CONTENTSOPENING SESSION:ADVANCED DISASTER MANAGEMENT BASED ON GREEN GROWTH PARADIGM
IN KOREA
PARK, YEON-SOO

1

FRAMEWORK / MECHANISM OF INTERNATIONAL COOPERATIONFOR DISASTER RISK REDUCTION AND JAPAN’S CONTRIBUTIONYASUYOSHI ICHIKAWA

13

DESIGNING RC STRUCTURES FOR FIRE
SAMARTH P. RAMDASI, SUDHIR MISRA AND P.S. GHOSHDASTIDAR

27

CLOSING SESSION:
ALOS AND SENTINEL ASIA FOR DISASTER MONITORINGHARUHISA SHIMODA

35

EARTHQUAKE COUNTERMEASURES FOR SAFER FUTURE IN KOREA
WAON-HO YI

37

PARALLEL SESSION 1:
RESEARCH ON DIGITIZED EMERGENCY RESPONHSE REPLANFOR PUBLIC SAFETY IN CHINA
FAN WEICHENG, GUOFENG SU and HONG HUANG

45

BEHAVIOR OF LEVEE MODELS REINFORCED WITH CUTOFF STEELSHEET-PILES DURING EARTHQUAKEMASARU KANEKO and JUNICHI KOSEKI

57

PERSPECTIVES ON SUSTAINABLE PRACTICES AND MATERIALSIN THE JAPANESE CONCRETE INDUSTRYMICHAEL HENRY and YOSHITAKA KATO

67

LANDSLIDE MOVEMENT AND DEFORMATION FOR DIFFERENT LENGTH
AND WIDTH OF LANDSLIDE MASSMUNEYOSHI NUMADA and KAZUO KONAGAI

77

CASE STUDIES OF COASTAL EROSION CONTROL BY GEOTEXTILETUBEEUN CHUL SHIN, SUNG HWAN KIM and YOUNG KEUN LIM

87

CROSS-BOUNDARY WATER RESOURCES ADAPTATION:
COMPARING A WATERSHED APPROACH AND A POLITICAL UNIT APPROACHAKIYUKI KAWASAKI, SRIKANTHA HERATH and KIMIRO MEGURO

97

COMARISON BETWEEN LEED® AND CASBEE BUILDING ASSESSMENT SYSTEMPRANAB J. BARUAH and KIMIRO MEGURO

107

PARALLEL SESSION 2:
IMPORTANCE OF OVERALL EVALUATION OF CIVIL STRUCTURES TO MAINTAINSAFETYTAKETO UOMOTO119NONLINEAR ANALYSIS OF SHEAR STRENGTHENING
OF REINFORCE CONCRETE COLUMNS BY USING FIBER REINFORCE POLYMERPRAGASIT JUNTANALIKIT and AMORN PIMANMAS131

EXAMINATION CONCERNING THE ACCEPTANCE INSPECTION
FOR QUALITY ASSURANCE OF STRUCTURAL CONCRETE
SHOTA MIZUKAMI, TSUGIO NISHIMURA, YOSHITAKA KATO andFUTOSHI KATSUKI

143

ESTIMATION OF SEISMIC CAPACITY OF KOREAN TYPICAL SCHOOL BUINDINGSUNDER DESIGN RESPONSE SPECTRUM
HO CHOI and YOSHIAKI NAKANO153

SHAKING TABLE TESTS OF TRADITIONAL TIMBER FRAMESINCLUDING KUMIMONO - MODELING OF HORIZONTAL RESISTANCE FORCE IUKO TSUWA and MIKIO KOSHIHARA

163

RESIDUAL DISPLACEMENT PREDICTION OF R/C BUILDING STRUCTURES
USING EARTHQUAKE RESPONSE SPECTRA
RISA KUWAHARA, NORIYUKI TAKAHASHI, HO CHOI and YOSHIAKI NAKANO

173

PARALLEL SESSION 3:
DHAKA CITY: HOT SPOT OR NOT?
MEHEDI AHMED ANSARY and MOHAMMAD SALAHUDDIN RIZVI183

PROPOSAL FOR REVIEWING AND REVISION PROCESS OF DISASTER
MANAGEMENT PLAN IN BANGLADESH -2007 CYCLONE SIDIR AS A CASE STUDYTAIKI KOU and KIMIRO MEGURO

193

DEVELOPMENT OF THE DISASTER INSTANCE MAP INCLUDING HISTORCIALDISASTER INSTANCES DAMAGED BY NATUAL DISASTERS
SEONHWA, CHOI

211

THE CONCEPT OF U-SAFE CITY AND SERVICE MODELS IN DISASTER PREVENTIONHYUN JU KIM and HYEONG JUN IM

219

METHOD FOR PROBABILISTIC DISASTER RISK EVALUATIONUSING RISK CURVE ANALYSIS
PARK, SOSOON

227

PARALLEL SESSION 4:
FAILURES AND SUCCESSES OF JAPAN'S EARTHQUAKE ENGINEERINGTSUNEO KATAYAMA

237

TRAP DOOR TESTS FOR EVALUATION OF STRESS DISTRIBUTIONAROUND A BURIED STRUCTUREHIROAKI EBIZUKA and REIKO KUWANO

245

FAILURE MECHANISM AND SEISMIC CAPACITY OF RC FRAMESWITH URM WALL CONSIDERING BEAM DEFORMATIONKIWOONG JIN, HO CHOI, NORIYUKI TAKAHASHI and YOSHIYUKI NAKANO251

A CASE STUDY OF GROUND CAVE-IN CAUSED BY SUBSURFACE EROSIONIN LARGE SCALE FILL GROUNDREIKO KUWANO and YUKIHIRO KOHATA

261

SEISMIC FRAGILITY FUNCTION FOR UNREINFORCED MASONRY BUILDINGSIN KOREA
JUNG-HAN LEE, HYE-WON KIM, BYUNG-CHEOL PARK and WAON-HO YI

269

PARALLEL SESSION 5:
INUNDATION PREVENTION AT THE UNDERGROUND SPACE IN KOREA
GYE WOON CHOI and SEONG JOON BYEON

277

EXPERIMENTAL STUDY OF MASONRY WALLETS MADE OF SHAPELESS STONESRETROFITTED BY PP-BAND MESH
KOTARO SAKURAI, NAVARATNARAJAH SATHIPARAN and KIMIRO MEGURO

291

SHEAR STRENGTHENING OF REINFORCED CONCRETE BEAMSUSING FERROCEMENTPRAGASIT JUNTANALIKIT, PANUWAT JOYKLAD and AMORN PIMANMAS301

A STUDY ON SEISMIC REPAIR COST OF R/C BUILDING STRUCTURES USINGA GEOMETRICAL DAMAGE ESTIMATION MODEL OF R/C MEMBERSNORIYUKI TAKAHASHI and YOSHIAKI NAKANO

313

EXPERIMENTAL STUDY ON PP-BAND MESH SEISMIC RETROFITTING
FOR LOW EARTHQUAKE RESISTANT ARCH SHAPED ROOF MASONRY HOUSESNAVARATNARAJAH SATHIPARAN, PAOLA MAYORCA, KIMIRO MEGURO

323

REPLACEABLE SLAB OF OPEN-TYPE PIERS AS NEW COST-EFFECTIVETECHNOLOGYYUICHIRO KAWABATA, MITSUYASU IWANAMI, EMA KATO, HIROSHI YOKOTA andMASAHIKO FURUICHI333

DESIGN OF CRACK SELF-HEALING ON CONCRETE STRUCTURES
TAE-HO AHN and TOSHIHARU KISHI

343

EXPERIMENTAL EXAMINATION ON THE REPAIR EFFECTOF EMERGENCY RAPID RETROFITTING METHOD TST-FiSH
MASAMITSU SUZUKI, RYOTA KASAKURA, MASANORI ITO and YOSHITAKA KATO

355

PARALLEL SESSION 6:
INFORMATION MANAGEMENT FOR DISASTER REDUCTIONKIMIRO MEGURO and SHINYA KONDO

365

DEVELOPMENT OF LIFE CYCLE MANAGEMENT SYSTEM FOR OPEN-TYPE WHARF
EMA KATO and MITSUYASU IWANAMI383

URBAN DISASTER AND EMERGENCY EXERCISE IN REAL TIME 3D SOCIAL
VIRTUAL ENVIRONMENTS
ALI ASGARY

393

QUANTITATIVE EVALUATION OF ESCAPE SAFETY CONSIDERING EXTENSIONOF ESCAPE TIME BY ESCAPE DISTANCE AND ESCAPE BARRIER
JEONG GUNSIK and YOUNGCHULL AHN

405

PROPOSAL OF AN EVACUATION NAVIGATING SYSTEMIN CASE OF NATURAL DISASTERAYAKO FUKUSHIMA, BYONG-PYO JEONG, ATSUYUKI IDA, SHIN’ICHI TSUCHIYA andYUJI HASEMI

417

INFLUENCE OF THERMAL CONDITION ON THE WIND ENVIRONMENT EVALUATIONFOR BUILDING DESIGNHONG HUANG, RYOZO OOKA and HOM B. RIJAL

427

EMERGENCY MANAGEMENT IN KOREA: JUST STARTED, BUT RAPIDLY EVOLVING1
KYOO-MAN HA439

CRITICAL REVIEW OF THE STANDING ORDERS ON DISASTER MANAGEMENT,BANGLADESHRIPON HORE and MEHEDI AHMED ANSARY

445

PARALLEL SESSION 7:
SEISMIC PERFORMANCE OF REINFORCED CONCRETE STRUCTURESSHIMA HIROSHI

453

MODELING OF RC COLUMN WITH LAP SPLICES STRENGTHENEDBY FIBER REINFORCED POLYMER
DAM XUAN THAI and AMORN PIMANMAS463

AN EXPERIMENTAL STUDY FOR THE QUALITY EVALUATION OF COVER CONCRETE
KENJI HAYAKAWA and YOSHITAKA KATO

483

THE SECULAR CHANGE OF TIMBER BRIDGE, “KINTAI-KYO”
MIKIO KOSHIHARA

493

THE SAFETY ASSESSMENT TO URBAN CITY OF COASTAL AREA
BY WAVE-STRUCTURE INTERACTION
JIN-HONG KIM and SUNGDUK KI

501

PARALLEL SESSION 8:
ANALYZING IMPACTS OF SEA LEVEL RISE ON COASTAL CITIES WITH FOCUS
ON FLOODS AND SALINITY FLUX
DUSHMANTA DUTTA and JABED ABDUL NASER BHUIYAN

511

INTEGRATED PLAN FOR FLOOD DISASTER MANAGEMENT BY CLIMATE CHANGESKEE-OH SHIM, BYUNGTAE YOO and KYUNGHO PARK

521

HYDRAULIC EFFECTS ON VEGETATION IMPACT BY FLOOD FLOW
IN URBAN STREAMS
JIN-HONG KIM

529

EFFECT OF CLIMATE CHANGE IN BANGLADESH AND DAMAGESDUE TO TWO RECENT CYCLONESMEHEDI AHMED ANSARY and SAIDUR RAHMAN

537

COMPUTATIONAL ASSESSMENT OF WINDSTORM HAZARD IN URBAN CANYONSUNGSU LEE, HAKSUN KIM, GULGI CHOI and KWANGHYUN NA

551

PARALLEL SESSION 9:
DEVELOPMENT OF THE WEB-BASED TOTAL SAFETY MANAGEMENT SYSTEM
GEONHO HONG, CHEEKYEONG KIM and HEEKYU KIM

557

CURRENT DEVELOPMENT OF AN INTEGRATED STEEP-SLOPEMANAGEMENT SYSTEM FOR URBAN DISASTER RISK REDUCTION IN KOREA
DUGKEUN PARK, JEONGRIM OH, YOUNG-KARB SONG, YOUNG-JIN SON
and MIN-SEOK LEE

567

PROPOSAL OF EFFICIENT ROAD SPACE UTILIZATION IN URBAN ARTERIAL STREETSHINJI TANAKA and MOTOMUNE KATAOKA

573

STUDY ON THE COASTAL DISASTER PREVENTION SYSTEMUSING EVACUATION MODEL
SUNG JIN HONG, TAEK JO KOH and HYOUNG SEONG PARK583

INTRODUCTION OF DISASTER IMAGINATION WORKSHOPINTO RISK-MANAGEMENT TRAINING FOR NURSERY SCHOOL LEADERSMARIKO ABE, KIMIRO MEGURO and MARI YOKOYA

591

APPLICATION OF ANALYTIC NETWORK PROCESS TO DESIGN EMERGENCY CAPABILITY 599
ASSESSMENT INDEX SYSTEMSHEN SHIFEI, CHU YANYAN, DU LIGANG, QIAO LIFENG and YANG RUIEMERGENCY RELIEF DELIVERY WITH DEMAND CONFLICT COORDINATIONAND GOAL SOFTENINGZHANG JING, SHEN SHIFEI and YANG RUI

609

PARALLEL SESSION 10:
REGIONAL FLOOD RISK MANAGEMENT IN KOREA
Special Presentation: BYUNGHA SEOH, BYUNG SIK KIM and DAE WON JANG

615

A COMPARATIVE STUDY OF URBAN VULNERABILITY
BETWEEN DHAKA AND TOKYO
MD. FAIZ SHAH and OSAMU MURAO

629

A STUDY ON THE EFFICIENT EARLY-WARNING METHODUSING COMPLEX EVENT PROCESSING (CEP) TECHNIQUESHYUNG WOO KIM, GOO SOO KIM and SUNG BONG CHANG

639

A SURVEY ON RESIDENTS’ RESPONSE TO EARTHQUAKE EARLY WARNING
AT THE 2008 IWATE-MIYAGI INLAND EARTHQUAKE IN JAPANMIHO OHARA, YASUHITO JIBIKI, NAOYA SEKIYA, TETUSTARO SUMI,
KIMIRO MEGURO and ATSUSHI TANAKA

649

SEISMIC MICROZONATION OF COX’S BAZAR MUNICIPAL AREA
A. B. AFIFA IMTIAZ and MEHEDI AHMED ANSARY663

DEVELOPMENT OF WINDRISK○R ; A TOOL FOR REGIONAL WINDSTORMRISK ASSESSMENTSUNGSU LE, HEE-JUNG HAM, DONGHYUN LEE, YOUNGKYU LEE, JASUP KOO
and JINA JEONG

677

DEVELOPMENT OF AN INTELLIGENT SMOKE CONTROL PROCEDUREUSING HVAC OPERATION AND DOOR CONTROL STRATEGY IN A BUILDING FIRE
CHU YANYAN, ZHANG HUI

683

PARALLEL SESSION 11:
EVALUATION ON PERFORMANCE DEGRADATION OF DETERIORATEDCIVIL INFRASTRUCTURE
HIROSHI YOKOTA, YOSHITAKA KATO, REIKO KUWANO, TAKAHIRO ENDO
and EMA KATO

693

REPORT OF NON-DESTRUCTIVE TESTING FOR AN AIRPORT RUNWAY
AND BRIDGE ASFALT PAVEMENT BY USING INFRARED CAMERANOBORU SATO

701

RECOVERY MECHANISM OF FIRE-DAMAGED HIGH-STRENGTH MORTARYOSHITAKA KATO, MICHAEL HENRY and MASAMITSU SUZUKI

707

EXPERIMENTAL STUDY OF ULTRA HIGH STRENGTH CONCRETE
AND REACTIVE POWDER CONCRETE STRUCTURES UNDER BLAST LOADING
NA-HYUN YI, SUNG-HWAN PARK, JANG-HO JAY KIM, KEUN JOO BYUN andJONG -KWON CHOI

717

OPTICAL SENSOR AND NEURAL NETWORKS FOR REAL-TIME MONITORINGAND ESTIMATION OF HAZARDOUS GAS RELEASE RATEWON SO, JAMIN KOO, DONGIL SHIN, KYOSHIK PARK and EN SUP YOON

727

EARLY EMERGENCY SYSTEMS BASED ON 3DGIS
FOR DISASTER PREVENTION SAFETY-CITY
YOUNG JIN PARK

737

IMPACT RESISTANCE OF REINFORCED CONCRETE WALL
OF BREAKWATER CAISSONTAKU MATSUBAYASHI, MITSUYASU IWANAMI and HIROSHI YOKOTA

747

A BASIC STUDY ON DEVELOPMENT OF NEW TRAINING SYSTEM
FOR BUILDING DAMAGE ASSESSMENT
MAKOTO FUJIU, MIHO OHARA and KIMIRO MEGURO

757

PARALLEL SESSION 12:
ANNUAL ENVIRONMENTAL CHANGES IN RUSSIA ANALYZEDBY REMOTE SENSING DATAHARUO SAWADA and YOSHITO SAWADA

765

EFFECT OF CROWN PROPERTIES OF CHAMAECYPARIS OBTUSA TREEIN JAPAN FOR DEM CREATIONTAKAHIRO ENDO and HARUO SAWADA

773

SIMULATION OF EXPLOSION MODEL WITH GIS/RS DATA IN HILLY URBAN AREAS
EUNMI CHANG and HYUNGSUK KIM

779

IDENTIFICATION OF GROUNDWATER POTENTIAL ZONESIN KEN-BETWA RIVER LINKING AREA USING REMOTE SENSING AND GIS
RAM AVTAR, HARUO SAWADA, S. MUKHERJEE and C. K. SINGH

787

ESTIMATION OF LAND SURFACE WATERCOVERAGE (LSWC)
WITH OPTICAL VS. MICROWAVESSHUMON MORI, WATARU TAKEUCHI and HARUO SAWADA

797

REMOTELY SENSED SOIL MOISTURE CHARACTERIZATIONWITH GROUND BASED MEASUREMENTSHYUNJIN PARK, JIYE KANG, JONG AHN CHUN, MINHA CHOI and JONGKYU LEE

807

ESTIMATION OF SEDIMENTS IN URBAN DRAINAGE AREAS
AND RELATION ANALYSIS FOR SEDIMENTS AND INUNDATION RISK USING GISPARK, MOO JONG and JUN, HWAN DON

815

OPENING SESSIONADVANCED DISASTER MANAGEMENTBASED ON GREEN GROWTH PARADIGM
IN KOREA
Park, Yeon-Soo
Vice Administrator
National Emergency Management Agency

ABSTRACT
Global warming changes in rainfall patterns, a rise in sea level, and awide range of impacts on plants, wildlife which effects on the typhoon, thetorrential rain, and the drought expecting to be continuing in the future withever-increasing size and scope. These changes make the natural andhuman-made disasters caused by combined effects of the aging society andchanging social structure which poses an unprecedented level of destruction
and damage. Also, there is a great need for national safety management
system on the epoch-making improvement of scientific disaster management
which appears new types of disasters through the exchange of traditional
disaster environment and responds actively to the rapid exchange of social
environment based on u-IT. To reduce the green gas and achievesustainable economic growth by developing low-carbon, eco-friendly
industries, the Korean government makes a plan a “green growth” as aplatform of river refurbishment project, in which four rivers will be
upgraded. The plans are for creating green belts, surrounding four mainrivers in Korea with trees and bicycle paths. The project to develop the Han,
Nakdong, Geum and Yeongsan Rivers flowing through the country's majorurban, industrial and farming areas and to reduce the damages from flood
related disasters around the rivers. The new paradigm is needed to manage
the damages regarding on the global warming or climate changes. The newadvanced disaster management based on green growth paradigm developedin this study provides the systematical information sharing networking
system and sharing real-time monitoring and simulating data amongst
government, local authorities and related organizations under both safety
management in normal times and circumstance management in disastertimes. In this study, the establishment of national safety strategy is also
reported to strengthen the functions such as prevention and preparation ofdisasters.

1. INTRODUCTION
Recently, localized heavy rain, typhoons have been increasing andintensity of them also increasing owing to climate change in the world.
Korea had major disasters for ten years such as flood on north part ofKyunggi-Do in 1998 and 1999, Typhoon Saomai in 2001, Typhoon Rusa in

1

October 2009, Incheon, Korea

2002, Typhoon Maemi in 2003, heavy rain on Kangwon-Do in 2006,
Typhoon Nari in 2007 and heavy rain on Bonghwa, Kyungbook in 2008
which disasters placed within the top ten made flood related damages almost
every year in recent.
IPCC reported on the 4th report that disasters regarding on extreme
events such as heat wave, drought and flood will be increased at the near
future. In the case of flood, increased intensity and frequency can be madelarge scaled damages at any time. Thus it is needed for reducing flood
related damages to prepare the disasters. However, changing of society
structures such as old-aged, information-oriented, urbanization andglobalized society changed life pattern which made centralization of
population and infra structure in the urban area and also increased
possibility of disasters. Thus, the central government derives a policy to
reduce the damages regarding on these natural and changed society structure
based disasters and make a long term roadmap for master plan to prepare
and reduce the damages regarding on extreme events.
In this study, concept of green disaster management was defined from
reviewing and analyzing of the factors to lead to disasters and advanced
disaster prevention and preparedness based on the green growth was also
reported from analyzing on various countermeasures collected from various
countries coping to climate changes.

2. GREEN GROWTH AND DISASTER MANAGEMENT
2.1 Concept of Green Growth
Now days, advanced countries concentrations their all effort to take apart a main role for leading market regarding on green growth. Although theconcept of green growth is not defined but green growth is new paradigm toincrease economics based on realizing the low carbon development and thegreen industry.
Here, low carbonized development means to realize the low carbon
economy development route through the low carbonization process. The
purpose of low carbon is the low carbon emission and advanced humanistic
development. With the low carbonization process, the industrial and energy
structures will be adjusted, which will affect the industrial employment
structure and the regional employment structure to some extent. It should be
noted that the low carbon development does not mean to restrict oreliminate the high carbon industry, but mean to eliminate the lag-behindproduction capacity, develop policies and methods for new technology, newenergies, etc. and realize the dual objectives of sustainable development andhandling of climate change.
Green industry means the industry which can promote theimprovement of ecological environment, with low energy consumption, lowpollution, high carbon efficiency and less rejects，such as Forestry. The
low carbon industry is not certainly the green industry, such as the service
for finance and insurance. Some environmentally friendly industries may bepresented as the industries with high emission and high pollution in a certain
period due to outdated technology; some industries can also become the2

New Technologies for Urban Safety of Mega Cities in Asia

green industry by improving the carbon efficiency and the low carbon
technology, such as the resource recovery and processing industry
2.2 Concept of Green Disaster Management
The Green Growth undertaken in the Republic of Korea show that
Green Growth can be a pioneering and concrete sustainable economic
development model which approach is spurring creativity and innovation forgreen markets and investments through new policies for greening theindustries and jobs.
The example of the policies undertaken in the Republic of Korea
show that Green Growth can be a pioneering and concrete sustainableeconomic development model. Green Growth is also becoming thefundament for joint action between the UN agencies in the region, as
advocated by ESCAP, to assist countries to build low carbon and climatechange resilient societies.
For this Presidential Committee on Green Growth formed Green
Growth Underwriting Project Team which team established five years load
map for low carbon and greening the industries. There are three strategies
and ten policies in this load map shown in Figure 1 where basic strategy
plan for disaster management was included in the project of strengthen forthe disaster management abilities.

Figure 1: Three strategies and ten policies developed by the Green Growth
Underwriting Project TeamTo follow up this national strategy of Republic of Korea, National
Emergency Management Agency (NEMA) introduces the Green Disaster
Management which means all activities to reduce or prevent the risks having
influence on the human society without harm to the environment. Throughthe Green Disaster Management, we reduce the risks of the disasters
increasing by growth oriented development and establish the base forcoexistence and harmony between human and nature on the all phages ofdisaster management such as the prevention, the preparedness, the response
and the recovery.
For successful of the Green Disaster Management, the establishmentof foundations such as database and technology for the Green Disaster
Management is needed at the first stage. Namely, the database and thetechnologies for estimating size and aspects of the disasters and minimize
the damages from disasters such as typhoon, drought, flood and flash flood

Advanced Disaster Management based on Green Growth Paradigm in Korea

3

October 2009, Incheon, Korea

are needed to manage disasters. Furthermore establishment of eco-friendly
countermeasures for disasters are also needed.
Accordingly, it is needed to develop the environmental friendly
technology for construction to prevent disasters or restoration technology torecover from disasters. Low carbonization technology and enhanced
management technology are needed to take a part on the national effort to
reduce greenhouse gases and secure safe and green industries through theextending of research and development support and supporting on the green
growth. These policies can make a green disaster management.

3. CHANGE OF RISK FACTORS DUE TO CLIMATE CHANGE
Now days, disaster events have been increasing and this trend is surprisingly
increased from later half of 1990s. Especially, various risks created from
artificial urbanization, destruction of the environment, estate development
make a increasing of vulnerabilities due to floods, landslide and inundationon the sea side and also change a risk pattern as follows:First, frequency and intensity of extreme events such as cold wave,
hot wave, typhoon, floods and drought will be increased. In the case of
Korea, rainy days was decreased but total amounts of rainfall and rainfall
intensity were increased (National Metrological Institute, 2007)
Second, a new disaster appear or disaster size is bigger on some area
because these areas are not undertaken the disaster before but are includedin the overlapping area of climate change now. It is expected to more rainon Korea but more dry on China which no rain can make desertification on
2/3 of area of South Korea and yellow send. Because the yellow send from
China make a big problems on spring season in Korea, it is needed
countermeasures to manage new or bigger disasters due to climate changes.
Third, the vulnerabilities from risks due to sea surface level increasing
and melting of ice is increasing. Recent, Tuvalu shown in Figure 2 on the
Oceania has suffering from unsufficient drinking water form high salinity
on the ground water and unsurfficient useful land from land contaminatedby much salt due to high sea surface level. From 2002, the project toemigrate refugees from Tuvalu to New Zealand has been performing.
However, 10,000 persons remaining on Tuvalu have insecurity tounexpected disasters.

Figure 2: Scene of Funafuti of Tuvalu’ capital city and Nukufetau

4

New Technologies for Urban Safety of Mega Cities in Asia

4. COPING TO CLIMATE CHANGE AND COUNTERMEASURESFOR DISASTER MANAGEMENT ON FOREIGN COUNTRIES
Although, the policies for reducing on greenhouse gases are performing tocope with climate changes, a new strategies and policies are needed toreduce the damages expected continuous or increasing for a while. In thisstudy, the strategy of USA to cope with climate changes and detailed sub
framework of Japan to adapt on climate changes were collected andanalyzed to derive the guideline for establishment of strategies on National
Emergency Management Agency and other related organizations.
4.1 The Strategy to Cope with Climate Changes in USA
4.1.1 Change Environmental Monitoring
The policy makers have to understand the effects on climate changes
specifically. Especially, monitoring on system for climate change andnatural phenomenon is important to establish the adaptable strategies tocope with climate changes.
Thus, NEMA has to collect data for natural phenomenon from
Ministry of Land, Transport and Maritime Affairs (MLTMA) to analysis ofrelationship between data and disasters and establish the organ anadministrative structures to monitor and analyze the metrological data anddata regarding on river system such as depth, discharges on the small andmiddle size river basin in which date are not collected from anyorganization.
4.1.2 Analyze Reason of Vulnerability and Finding Countermeasures
The policy makers can make a change and rise the effects with
monitoring on public factors to restrict ability of local government toproduce and cope with disasters and concrete coping policies.
Now, because economical indecency of local government and prevent
oriented disaster management were not enough, NEMA has to establish thepolicies to analysis vulnerabilities of each local government and to leadcoping policy of local government based on long-term plan. The basic law
to drive these policies is the Total Countermeasures for Flood Related
Disasters on the Law on Countermeasures for Natural Disasters and it isneeded to establish a policy to develop long-term plan to define thevulnerabilities of risk and reduce the risk under local government area
through this basic law.
4.1.3 Prepare long-Term Countermeasures
The effects on climate changes are should be considered to establish
or decide for policy such as investment for infra-structures and economic
intensive structures and land development, which have long-term effects on
the disaster management.
Thus the construction code for waste and rainfall channels and rivers
on urban areas considered future rainfall change aspects is should beconsidered and the research and development projects are should be
developed to establish the concrete construction code.

Advanced Disaster Management based on Green Growth Paradigm in Korea

5October 2009, Incheon, Korea

4.1.4 Prepare Countermeasures for Weak Point
The weak point such as infra-structure, eco-system, industry and local
government which these are sensitively changed by climate change andsociety structure changes are should be considered for top policy priority.
Especially, multi-purpose dams and rivers are should be recovered
and reinforced for considering on climate change effects. NEMA has todevelop the codes or guidelines to add on the rule of disaster assessment for
urban plan and land use plan to cope with climate change on the small andmiddle size urban area.
The new model adapted on Korea is should be developed to determineor estimate the most dangerous area on each local government under low of
the Total Countermeasures for Flood Related Disasters and master plan is
also should be considered to develop the new model in phases.
4.1.5 Form and Reinforce Community Network
Strong relationship between confidential persons or companies is big
property to cope with climate change for person or company. Strong readersinspire to the organizations at the hard time and well organized and trained
persons spread information to the public persons for well adapting on
climate changes.
Thus MEMA have to make effort to build well organized community
network instead of government oriented disaster management. For this,
NEMA organizes system or supports to revitalize the panel on
countermeasures reducing disasters and the self control panel on disasterprevention.
4.1.6 Use Resources and Capacity of Local Governments
For development of countermeasures or method for coping method toclimate changes, NEMA has to consider cooperation works with local
universities and related companies which have professionalized knowledge
and technologies.
The capacity of local government are divided by disasters
management capacities of persons and local government in which systemfor education and public relation is necessary for teaching on importance ofdisaster management and raising disaster management capacities. Central
government have to reinforcement relating laws and budget system tosupport local government to establishment disaster management system
which system is not for waiting from central government but prevent andcommunity based network oriented system.
Furthermore, because self disaster management of company is also
important, NEMA study and organize system to revitalize the law for
supporting on private companies.
4,2 The Strategy to Cope with Climate Changes in Japan
Since 1984 Japan has operating the panel on total policy investigation for
countermeasures according to necessary for finding of basic solutions onflood related disasters which are formed by 13 experts working foruniversity and institutes. This panel made basic paradigms and urgent action

6

New Technologies for Urban Safety of Mega Cities in Asia

plans for disaster management and monitoring on results from management
every year. The main enhanced paradigms and action plans are following as:
4.2.1 Transform from Information Receiving to Information Sending
To escape from disasters, it is needed to reproduce the information
sending method and the information for escaping and reducing damages aresupported with estimated and monitored information which information
produced by system adapted on local area.
4.2.2 Transform to Society Knowing Guideline for Disaster
Management
The persons and local government who didn’t experience on any
disasters should learn the possible various disasters and the manual for
action.
4.2.3 Operating the Utilities for Disaster Prevention
Local government built managing system for disaster prevention andhigh level construction code to prevent disasters of natural disasters overdesign based on knowing of capacity for coping with disasters are
weakening and urban structure are changing.
4.2.4 Import New Improvement Technology
Recent, because natural disasters over construction code andconcentrated rainfall are being frequently it is needed to provide effective
safety standard before the disasters. For this, the new improvement
technology such as safety standard for land use and operating rules forutilities are needed.
4.2.5 Strengthen Capacity for Disaster Management on Local Region
To cope with society structure changes such as lower population, oldages, local society decline, urban structure changing, disaster prevention
system to attend many related participants, disaster prevention activities toattend residents and wide supporting system are prepared to strengthen thecapacity of local disaster management.

5. ESTABLISHMENT OF STRATEGY FOR THE GREENDISASTER MANAGEMENT SYSTEMAs shown the above, establishment of green disasters management system isknown as environmental friendly disaster management system to cope withclimate change. These green disasters management system shares its context
with recent disasters management paradigms focused on prevention in thedisaster management phases.
After all, preliminary activities for minimizing damage, grasping of
mechanism on disaster occurrence and development of prevention
technologies are should be performed based on a scenario of climatechanges, and the most important point in establishing green disastermanagement system is how to confront to meteorological disasters such as
extreme flood having renewed recent records. This study suggested 8

Advanced Disaster Management based on Green Growth Paradigm in Korea

7

October 2009, Incheon, Korea

driving assignments focusing on prevention, preparation, response andrehabilitation in disaster management phases for establishing green disasters
management system shown in Fig. 3.

Figure 3 Specific Plan of the Green GrowthFirst, strengthening of early warning ability on the damages of storm
and flood according to climate change is required for establishing
preliminary prevention system on disasters, and simultaneously a resetting
plan on disasters management standard with reasonable level responding tosevere meteorological phenomena should be carried out.
Second, weakness factor on disasters according to climate change forpropelling disaster prevention project vs. climate change shall be discovered,and then natural prevention project toward dangerous disaster district andsmall stream etc should be performed based on the results of weakness
findings. Specially, water environment including water control should becreated through management of small stream and maintenance project forconsidering ecological environment.
Third, strengthening of emergency rescue and relief system throughestablishing emergent response system on the vulnerable class should beexecuted for emergency response system and enhancement of emergency
response ability, and establishment of responding system after resetting
vulnerable class to climate change such as the aged population and city poor
is required. Also, development of training model with national participationis needed and voluntary participation of citizens is induced so as to be
spread widely through promoting consciousness on disasters. Specially,
insurance should be activated promptly to prevent the disaster by self-help
efforts on nature disaster which has been increasing rapidly according toclimate change.
Finally, environmental project should be performed by developing
construction material of environment and rehabilitation method which is
harmonized with natural environment to transfer from function oriented
recovery to make successful environmental recovery. Also, development ofenvironmental rescue goods and management of relief materials should beexecuted.

8

New Technologies for Urban Safety of Mega Cities in Asia

Through structural and unstructured tasks explained before, the green
disaster management could be a basement in making green safety nation
where nature and human are coexisting by executing low-carbonate andenvironmental friendly prevention.

6. RESEARCH S FOR GREEN DISASTER MANAGEMENT
6.1 Forecasting system establishment on flash flood in preparing forclimate change
Recent phenomena of abnormal climate is causing a lot of damages
owing to severe rain storm, and many damages are occurring annually byFlash flood stemming from abrupt rain storm. Specially, the Flash floodcauses a lot of personnel injury because the arrival time is too short andevacuation time is short, and thus forecasting system on the flood is very
necessary. For this purpose, NIDP is developing a system to estimate flash
flood effects from data receiving ultra-short term rainfall data bycooperation with National Institute of Meteorological Research. The system
can respond to abrupt severe storms owing to meteorological extraordinary
phenomenon.
6.2 Development on guideline for installation of reduction facilities
Recently, various cases experiments for rainfall-runoff phenomenon
were performed to test inducing rainfall’s penetration into the ground and its
storage. NIDP is installing and managing experiment facilities for reducing
rainfall runoff on laboratory located in Daejeon to develop installation
standard on rainfall penetration and rainfall storage facilities for flood
control.
Currently experiment on the footpath block with water permeability
and permeable trench and endeavoring were performed to develop
installation standard and to define the food control’s effect in reduction
facilities of rainfall runoff in case of designing flood-defense facilities forprotecting city from penetration.
6.3 New technology for levee repair of small stream
In our country the repair rate rose to a considerable level throughrepair projects focusing on current national rivers, but relatively that ofsmall streams is low, and thus a lot of damages from recent severe rainstorm are occurring in the small streams. Specially, passive repair method
for small streams is widely supplied and encouraged actually. In this regard,
the NIDP applies passive sea defense method centering on areas having
executed repair project for small streams, and intends to present a guidelineon proper sea defense method in relation with water quality and flood
control by monitoring.

Advanced Disaster Management based on Green Growth Paradigm in Korea

9October 2009, Incheon, Korea

6.4 Automated damage estimation system
Korea has performing damage estimation survey and then analysis forcause and damage amount before establishing rehabilitation plan. This
analysis for cause of damages and damage amount are used for establishingrough rehabilitation plan, and for suggesting the improvement rehabilitation
for coping with climate changes. Therefore, damage survey is one of mostimportant factors for rehabilitating activities, because there are someproblems to estimate damage amount because judging factor of survey’s
subject is effecting strongly. In this regarding, the NIDP developed atechnology which can get subjective damage information from survey byutilizing spacing images on damaged areas. Especially, this image
information can be used not only for damage survey but also for assistanceto field situation in case of large damage afterwards along with researchmaterials related to disasters.

7. CONCLUSION
This study reported a new disaster management system based on green
growth policies. The study also defined the green disaster prevention system
focused on necessities of establishment to countermeasures for disastermanagement for coexisting with nature along with responding efforts on
climate change. Also, disaster management policies and systems of theUnited States and Japan to respond to extreme events in recent wereanalyzed, and then the detailed strategy for propelling green disasterprevention fit to Korea was suggested. Finally, the NEMA can take a mainrole in establishing green disaster management system, and further the green
disaster management system will be a foundation for a safe country basedon the green growth.
Even though many researches are progressing to cope with climatechange, extreme events owing to climate change is become and natural
disaster according to climate change is also occurring differently with pastdisasters with bigger size and stronger intensive such as floods of typhoon
Nari at Jeju Island in 2007, heavy rain at Bongwha-Gun and North
Gyeongsang Province at 2008. Thus it is needed to establish the positive
countermeasure for disaster management system adapted in Korea.
German philosopher, Geothe said that positive activities is importantsuch like applying knowledge to real problems and acting according towillingness, rather than our knowledge and intentions to do something. Thus,
only positive responding for disasters regarding on climate change will give
us safe society and economy at the future. Therefore, a fact that desirable
future could be achieved through actions and practices of our generation
should not be forgotten.

REFERENCES
Borga, M., Gaume, E., Martina, M. and Thielen, J., 2008. Realtime Guidance for10

New Technologies for Urban Safety of Mega Cities in Asia

flash flood risk management, FLOODsite Consortium.
Hey, D., Kostel, J., MonTgomery, D., 2009. An Ecological Solution to the
Flood Damage Problem.
Federal Emergency Management Agency, The Great Midwest Flood:
Voices 10 Years Later, FEMA Report.

Advanced Disaster Management based on Green Growth Paradigm in Korea

11

FRAMEWORK / MECHANISM OF
INTERNATIONAL COOPERATION FOR
DISASTER RISK REDUCTION AND
JAPAN’S CONTRIBUTION
Yasuyoshi Ichihashi
Visiting Professor, ICUS, IIS, University of Tokyo, Japanysich555@iis.u-tokyo.ac.jp

ABSTRACTIn recent years, there has been increased international recognition
that damages caused by disasters seriously interfere with “human security”
by hindering development efforts and the accomplishment of “sustainable
development.” Furthermore, more recently, there is also growing alarm
about global climate change and increasing disaster risks.
Japan, as one of the countries that suffered from frequent natural
disasters including earthquakes, tsunamis, typhoons, volcanic eruptions,etc., has accumulated its own knowledge and culture to cope with large
scale natural disasters, promoted scientific approaches and developed
technologies in related areas. Japan has also developed its own domestic
system of early warning and training, immediate rescues, and policies forreconstruction and long term development.
Against such background, Japan has been actively promoting,often by taking initiatives, international efforts to strengthen effective
cooperation in the area of disaster risk reduction.
Central to the issue of setting up international framework andmechanism and securing a wide ranging international cooperation was the
adoption of “Hyogo Framework for Action” (HFA) at the UN World
Conference on Disaster Reduction held in 2005 in Kobe, Japan. Since thenthe HFA already became an international norm and standard document in
the context of disaster risk reduction.
This paper briefly reviews the process and accomplishments so far
in the setting up of framework and mechanism of international cooperation
on disaster risk reduction, reviews also Japan’s contribution in the same
area, and calls for a renewed attention to integrate various efforts into a
concerted international cooperation.

1. BRIEF REVIEW: SETTING UP OF FRAMEWORK AND
MECHANISM OF INTERNATIONAL COOPERATION ON
DISASTER REDUCTION(1)

To mitigate damages caused by disasters, it is necessary to coordinate
pre-disaster measures and post-disaster efforts of emergency relief and13

October 2009, Incheon, Korea

recovery/reconstruction. Traditionally, international cooperation during
large scale disasters has been centered on humanitarian assistance either
bilaterally between the governments, or through UN organizations
and/or International Federation of Red Cross and Red Crescent Societies.
Currently, UN Office for the Coordination of Humanitarian Affairs(OCHA) coordinates search and rescue activities in emergency
situations. (The UNDRO, established in 1971 by the UN General
Assembly resolution, was incorporated into the UN Department of
Humanitarian Affairs (DHA) in 1992.
This Department was
reorganized into OCHA as part of Headquarter of the United Nations.
One of OCHA offices is located in Kobe. ) (http://ochaonline.un.org)(2)
On the other hand, pre-disaster measures have not necessarily been
given priority in many country’s development strategies, and it has
become recognized that such efforts are essential in achieving
sustainable development. In 1987, following a joint submission from155 countries led by Japan, UN General Assembly decided that 1990s
be the “International Decade for Natural Disaster Reduction.” (IDNDR)(3)
In the mid-decade year of 1994, Japan hosted World Conference on
Natural Disaster Reduction in Yokohama, the first international
conference on disaster risk reduction, and contributed in the adoption of
Yokohama Strategy and Plan of Action for a Safer World.
(4)
Towards the end of the decade, UN General Assembly adopted“International Strategy for Disaster Reduction.” (ISDR) in1999 tosucceed IDNDR.
UN placed secretariat in Geneva.
(http://www.unisdr.org) Thereafter in 2003, UNGA adopted that Japanhosts the next World Conference on Disaster Reduction.
(5)
In January 2005, Japan hosted the UN World Conference on Disaster
Reduction (WCDR) in Kobe, Hyogo Prefecture. Along with the review
of “Yokohama Strategy” implemented for 10 years, the participants ofthe conference examined a guiding framework in disaster risk reduction
and adopted the “Hyogo Framework for Action 2005-2015” (HFA) thatgathered up priorities of the disaster risk reduction measures that eachcountry and international organization should carry out for the coming
ten years.
(6)
It was also decided that the UN/ISDR plays a key role in following
up the implementation of HFA, and the result to be reviewed in the
United Nations Commission on Sustainable Development 2014/2015.
“Hyogo Declaration” was adopted at the same time, which advocatedthe importance of consolidating sustainable development and disasterrisk reduction, and spreading the culture of disaster risk reduction.
Furthermore, the Special Session on Indian Ocean Tsunami ofDecember 2004, just before the Conference was held on the initiative ofJapan. At this session, Common Statement was released calling for theestablishment of an effective and durable tsunami early warning system
for the Indian Ocean.
(7)
At the WCDR, Japan’s Prime Minister (then) Koizumi announced
Japan’s Initiative for Disaster Reduction through ODA for thecomprehensive and consistent cooperation strategy corresponding toeach stage of disaster prevention, emergency relief and reconstruction.

14

New Technologies for Urban Safety of Mega Cities in Asia

Thereafter at the Asia-Africa summit meeting held in April 2005, Japanannounced that it will be providing more than US$ 2.5 billion (including
more than US$ 1.5 billion of grant aid) over the next five years inassistance for disaster prevention and mitigation, and reconstruction
measures in Asia, Africa and other regions.
(8)
One of the strategic goals of the “Hyogo Framework of Action” is tointegrate risk reduction approach into post disaster recovery. To
translate this policy into practice, the International Recovery Platform(“IRP”) was established in 2005 as a network of organizations such as
ISDR, UNDP, ILO, the World Bank, ADRC (Asian Disaster Reduction
Center), and several countries including Japan. Having its secretariat in
Kobe, IRP is promoting knowledge sharing, capacity building andsupportsofthedisasterrecoveryprograms.
(http://www.recoveryplatform.org/jp/)(9)Considering the disaster risk reduction as an important part of theagenda for poverty reduction, the World Bank established the “Global
Facility for Disaster Reduction and Recovery” (“GFDRR”), in 2006, tosupport each country to mainstream the disaster reduction into national
development plans and policies in line with the HFA. Japan supports
effective implementation of this facility and pledged US$ 6 million
contribution. Japan also acts as a member of the donor meetings andparticipates in the Result Management Committee (RMC).
(http://www.worldbank.org/japan/jp)(10)
To follow up and to secure implementation of the HFA, UNGA in2006 decided to establish the Global Platform for Disaster Reduction asa forum to discuss matters related to HFA implementation at country,
regional and international level. The 1st meeting of the Global Platform
was held in January 2007, and the 2nd in June 2009, in Geneva.
(http://www.preventionweb.net/globalplatform/2009)(11)
Thus the current international framework has the HFA as its guiding
principles, the global platform as the international forum to review andpromote the implementation of the HFA, and ISDR as the central
secretariat body of the coordination. National progress reports are being
submitted every two years.

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution15

October 2009, Incheon, Korea(12) Table 1 shows evolution of the international framework on disaster
reduction since late 1980’s.
Table1:

16

New Technologies for Urban Safety of Mega Cities in Asia

2. PROMOTING COOPERATION IN ASIA
(1)

It is crucial to promote cooperation on disaster risk reduction atregional level where countries share the meteorological, geographicaland topographical characteristics. Especially in Asia, a number ofnatural disasters occurred as represented by the Sumatra Earthquake andthe subsequent Great Indian Ocean Tsunami in December 2004,
Pakistan Earthquake in October 2005, Sichuan Earthquake in May 2008
and others. Such disasters take a heavy toll of lives and damage thesustainable development of the affected countries. Japan has beenpromoting regional cooperation including information sharing, humanresources development through the activities of Asian Disaster

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution

17

October 2009, Incheon, Korea

Reduction Center (ADRC).
(2)ADRC was established in July 1998 in Kobe, Hyogo Prefecture, as aresult of Asian Disaster Reduction Experts Meeting in 1996 and Asian
Disaster Reduction Cooperation meeting in 1997. Currently it has 27
member countries and 5 advisory countries and organizations, and themain activities cover the following areas: (a) accumulation andprovision of information on natural disasters and disaster risk reduction,(b) studies on the promotion of disaster reduction cooperation, (c)gathering of information on emergency relief during times of disaster,(d) developing materials for dissemination of knowledge and raisingdisaster risk reduction awareness, (e) developing education and training
programs dealing with disaster risk reduction information.
( http://www.adrc.asia )(3)
In November 2008, Asian Conference on Disaster Reduction 2008
was co-organized in Bali by the Government of the Republic ofIndonesia, the Government of Japan, the United Nations Secretariat ofthe International Strategy for Disaster Reduction (UN/ISDR) and the
Asian Disaster Reduction Center (ADRC), and discussed current statusof the HFA implementation in each country and ways for its further
promotion.
(4)
Apart from the ADRC, multilateral cooperation on disaster risk
reduction in Asia-Pacific region has been formed in the following
manner:(a) Asian Ministerial Conference on Disaster Reduction was first hosted
by China in September 2005, and subsequently hosted by India in
November 2007 and by Malaysia in December 2008, and discussed
ways to promote regional cooperation.
(b) In December 2005, at the 9th ASEAN-Japan Summit in Kuala
Lumpur, the collaboration between ASEAN and Japan in the field of
disaster management was reaffirmed on the Joint Statement, and at
the 10th ASEAN-Japan Summit in Cebu, Prime Minister (then) Abe
declared that Japan would contribute about US$ 5.6 million toprovide to ASEAN countries materials for disaster risk reduction.
(c) In January 2007, at the 2nd East Asia Summit meeting in Cebu,
Philippines, Japan announced to provide, by making use of JapanASEAN Integration Fund (JAIF), US$ 3million in total to support
ADRC projects on disaster risk reduction in ASEAN member
countries. The projects were: (i) Promotion of Disaster Education in
Schools, (ii) Capacity building of Local Government Officials on
Disaster Management, (iii) Utilization of satellite image on disastermanagement, and (iv) Development of web-based GLIDE associateddisaster event databases for ASEAN countries. These projects started
in 2008.
(d) In April 2009, Japan also announced the following additional
contributions in disaster reduction area as one of the measures tohelp Asian countries to cope with global economic and financial
crisis: (i) To provide additional fund of US$ 13 million to JAIF inorder to assist ASEAN countries to stockpile emergency supplies fortheir mutual assistance use, (ii) To develop human resources in

18

New Technologies for Urban Safety of Mega Cities in Asia

ASEAN countries to evaluate and analyze disaster risks, (iii) To
provide US$ 6 million in total, by making use of JAIF, to establish
information and communication system in ASEAN countries during
times of disaster, (iv) To carry out trainings for about 300 personnel
from EAS countries over 5 years time in the field of disaster risk
reduction, including those from ASEAN countries mentioned in (ii)above, and also to provide opportunities for the students and youths
who visit Japan under the “Japan-East Asia Network of Exchange
for Students and Youths (JENESYS) Program to experience disasterrisk management in Japan.
(e) Japan-US-Australia
In June 2008, at the Japan-US-Australia trilateral strategic dialogue
at the ministerial level, a joint statement was issued in which it wasstated that the three countries committed to strengthen cooperation
on disaster management and emergency response, and to develop
guidelines to facilitate this trilateral cooperation and information
sharing on humanitarian assistance and disaster relief.
(f) Japan-China-South Korea
In December 2008, at the Japan-China-ROK trilateral summit, aTrilateral Joint Announcement on Disaster Management
Cooperation was issued, in which the leaders of the three countries
shared that it is crucial for the three countries to share information
on projects, initiatives, good practices, lessons learned and scienceand technologies to strengthen disaster management capability. It
was also stated that the three countries will enhance cooperation in(i) developing comprehensive disaster management framework, (ii)developing measures and systems to reduce vulnerability to disasters
and to minimize damage from disasters, (iii) strengthen effective
disaster management at the national, local and community levels.
Moreover, in order to implement the above cooperation, the threeleaders shared the view to hold trilateral heads of government
agency and expert level meetings on disaster management in rotation,and to consider the first meeting to be hosted by Japan in 2009.
(g) ARFASEAN Regional Forum (ARF) has also been active in disaster
relief. It places disaster relief as one of the priority areas ofactivities, and has been promoting regional cooperation in the AsiaPacific region. As one of such activities of the ARF, in May 2008, a
multi-national disaster relief desk top exercise was conducted inIndonesia, and in May 2009, a multinational disaster relief field
exercise was carried out for the first time in the Philippines. The
concept of the field exercise was a search and rescue activity for alarge scale damages caused by a typhoon in Luzon, to which
civilians take the lead with the military assist. 25 countries and theEU participated in this field exercise and relevant events thatcoincided with the exercise and Japan also participated in a large
scale, combining personnel/equipments/aircrafts of Ministry ofForeign Affairs, JICA, Ministry of Defense and
Ground/Air/Maritime Self Defense Force.

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution19

October 2009, Incheon, Korea

3. JAPAN’S CONTRIBUTION
Since the initiatives that Japan has been taking in the field of multilateral
cooperation for disaster reduction are already described in the above
sections, this section mainly focuses on a brief look at Japan’s bilateralassistance through ODA.
(1)
As mentioned in 1. (7) in the above, Japan announced Initiative forDisaster Reduction through ODA for the comprehensive and consistentcooperation strategy corresponding to each stage of disaster prevention,
emergency relief and reconstruction. Thereafter at the Asia-Africa summit
meeting held in April 2005, Japan announced that it will be providing morethan US$ 2.5 billion (including more than US$ 1.5 billion of grant aid) overthe next five years in assistance for disaster prevention and mitigation, andreconstruction measures in Asia, Africa and other regions.
(2)
By 2007, the third year of the pledged US$ 2.5 billion over 5 years,
total expenditure of the Japanese ODA in the field of disaster risk reduction
during 2005-2007 achieved US$ 2.53 billion, and the target was already met
in advance. Break-downs by each year are as follows: (Figures include bothbilateral ODA and contribution through multilateral organizations)
FY
2005
2006
2007

US$
approx. 840 mil.
approx. 820 mil.
approx. 870 mil.

J\approx. 89.8 bil.
approx. 90.9 bil.
approx. 100.7 bil.

(3)
Break-downs of Japan’s bilateral ODA for disaster risk reduction
during 2005-2007 by forms of assistance are as follows:
FY
2005
2006
2007

20

Grant
J\ 22.6 bil
J\ 16.2 bil
J\ 22.6 bil

Loan
J\ 55.9 bil
J\ 67.7 bil
J\ 60.4 bil

Total
J\ 78.5 bil
J\ 83.9 bil
J\ 83.0 bil

New Technologies for Urban Safety of Mega Cities in Asia

(4)Break-downs of bilateral ODA by types of disaster in FY 2007 are
as follows:
Assistance by Types of Disasters

Road Disaster(Bridge Constructionetc.) 4%

Drought (Food Aidetc.) 12%Windstorm/Flood(Prevention
Planning etc.) 25%

Information for
Disaster Prevention(MeteorologicalRader/Warning
System etc.) 3%
Earthquake/Tsunami (Emergency
Relief/Reconstructi
on etc.) 28%

Soil erosion(Reforestation etc.)
28%(5)Initiative for Disaster Reduction through ODA divides the types ofcooperation by different phases of disaster. (a) Integration of disasterprevention into development policies, (b) Rapid and appropriate assistancein the immediate aftermath of disaster, and (c) Cooperation that extend fromreconstruction to sustainable development.

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution21

October 2009, Incheon, Korea(a) Integration of disaster prevention into development policies
In order to minimize the escalation of damage caused by natural
disasters in developing countries, it is essential to take into account the
preparedness for possible disasters. In order to introduce the “culture of
prevention” into long term national policy, city planning, regional
planning, regulations and standards, Japan will provide assistance
relating to policy recommendations, institution–building and humanresources development. It includes as elements:- Institution building that incorporates the perspectives of disasterprevention,- Training of experts and developing capacity for disaster prevention,- Raising awareness and building capacity of local communities on
disaster risk reduction.

<Case File 1> Rising Capacity to Respond and Enhancing Disaster
Prevention Framework of Administration Institutions (Turkey)
In 1999, Turkey was hit by two large earthquakes that exceeded
magnitude of seven on the Richter scale, causing heavy damages leaving
more than 25,000 dead. The Government of Japan extended assistancethrough Loan Aid, namely “Emergency Measures for Rehabilitation ofEarthquake Damage” (FY 1999, J\ 23.6 billon) and “The Seismic
Reinforcement Project for Large Scale Bridge in Istanbul” (FY 2001, J\12.0
billion). Reflecting that government bodies’ inability to adequately respond
may have led to far larger scale of damages than estimated, the Governmentof Turkey requested the Government of Japan for technical assistance inraising its administrative capacity to respond to disasters, and enhancing its
disaster prevention framework.
Technical assistance that began in 2001 emphasized disasterprevention trainings of administrative officials. First, Vice-governors anddistrict governors of Turkey received trainings on the efforts ofreconstruction after Hanshin/Awaji Earthquake. From 2003, using thetraining curriculum developed by returned-trainees, “Disaster Prevention
Measure Training Project” was conducted to 260 Vice-governors anddistrict governors. From 2005, “Earthquake Damage Mitigation Project”
was carried out which also included trainings to mayors and urban-planning
directors.
These efforts are furthering the city planning that would not repeat thedisaster tragedy and enhancement of administrative institutions’ capabilities
to cope with disasters.

22

New Technologies for Urban Safety of Mega Cities in Asia

(b) Rapid and appropriate assistance in the immediate aftermath ofdisasterIn the immediate aftermath of a disaster, Japan will provide rapid
assistance such as dispatching the Japan Disaster Relief Team forlifesaving, providing basic necessities and food aid, and restoration ofbasic human economic and social infrastructure. In addition, Japan will
dispatch experts specializing in such field as training, risk assessment ofbuildings and flood control to assist in the human capacity development
which will enable an emergency response. The contents are:
- Prompt and appropriate emergency assistance,- Training of experts and transfer of expertise for emergency response,- Food aid in response to food shortage caused by disasters,- Coherent cooperation corresponding to each phase of disaster.

<Case File 2> Seamless Assistance after the Occurrence of Disaster(Indonesia)
In May 2006, heavy damage was caused by a large-scale
earthquake that generated in the Central Java in the Republic ofIndonesia with more than 5,700 death casualties. Utilizing learned
lessons from the past experiences in post-disaster assistance andrecognizing the importance of seamlessly connecting emergency
response to recovery and reconstruction phase, the Government of Japan
carried out assistance in close coordination of various schemes.
Directly after the earthquake, dispatch of Japan Disaster Relief
Team (JDR: Medical Team and Unit of the Self-Defense Force), anddistribution of emergency relief goods and assistance of goods throughemergency grant aid cooperation were conducted. For example,
distribution of tents, blankets and other goods necessary for the period of
evacuation, emergency treatment of the injured, and establishment of
temporary classrooms for the resumption of school education were
implemented.
After the emergency phase, recovery and reconstruction assistancewere conducted seamlessly through utilization of Grant Aid for Disaster
Prevention and Reconstruction as well as technical assistance. For
example, official resumption of school education was assisted throughdistribution of textbooks and other goods upon reconstruction of schoolbuildings and training of teachers. In addition, upon reconstruction ofhealth center, technical assistance such as treatment of trauma andrehabilitation assistance were conducted to enhance medical service.
Such seamless assistance conducted directly after the disaster has
facilitated steady progress of reconstruction in Bantur Province ofCentral Java.

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution23

October 2009, Incheon, Korea(c) Cooperation that extend from reconstruction to sustainable
development
Japan will support actions by developing countries to end the vicious
circle of disaster in the reconstruction phase towards developing adisaster-resilient community and sustainable development, targetingareas where severe damage from earthquakes, tsunamis, storms, andfloods is widely spread and frequent occurrence of natural disaster ishindering economic growth. For this purpose, Japan will provide
cooperation with an emphasis on economic and social infrastructure,building, and systems that are disaster-resilient. The contents are:
- Assistance for developing disaster-resilient economic and social
infrastructure and architecture,- Dissemination of disaster resilient systems and technology,- Provision of financial assistance necessary for reconstruction anddevelopment.

<Case File 3> Prevention of Water Disasters caused by Intensive Rainfall in
the Urban Area (Tunisia)
While majority of Tunisia’s urban area is within sub-arid area,
intensive rainfalls in a short period of time cause floods that could lead toextensive damages. To prevent such damages, the Government of Japandecided to extend its assistance to “Inundation Protection Project” (FY
1997, approximately J\ 9,100 million) through Loan Aid in response to arequest from the Government of Tunisia.
This project is a counter-flood measure plan in Ariana situated in thenorthern Tunis, the capital, and Kairoan which is the hub of the country’s
central region. In Ariana, rehabilitation of drainage and reservoirs as well
as rehabilitation of existing channels are in progress along the Enkhit River.
In Kairoan, flood control channels and river dikes are being constructed for
Merguellil River and the Zeroud River, which flow into the Kairouan Plainthat surrounds the city.
These efforts have mitigated flood damages and have promoted
economic and social development in the targeted areas. In particular, in
Kairouan, the project will make it possible for a large area of land that has
not been utilized because of floodi ng to be used effectively for agricultural
purposes.

(6)
Apart from the ODA program as described in the above, Japan has
experienced extensive devastation caused by a multitude of disasters
including earthquakes, tsunamis, typhoons, floods, and volcanic eruptions.
Based on harsh experiences, Japan developed disaster management system,and takes full advantages of its experience, knowledge, and technologies tocontribute to the improvement of disaster management capabilities in thedeveloping countries. Some examples are as follows:(a) Early Warning System and Hazard Maps

24

New Technologies for Urban Safety of Mega Cities in Asia

For early warning systems to be useful in mitigating natural disasters,
it is necessary:(i) to enable the issuance of prompt and accurate early warning
information based on accurate, real-time measurements of various
natural phenomena and scientific data analysis.
(ii) to incorporate systems for sharing warning information among
relevant organizations and disseminating it to people, and(iii) to raise awareness on disaster reduction to ensure that more timely
and appropriate disaster risk reduction actions are taken based on thewarning information issued.
In Japan, such early warning systems are established throughout
the country.
Also, Japanese municipalities generally create and distribute hazard
maps that show the areas vulnerable to earthquakes, tsunamis, volcanic
eruptions, floods, and landslides, as well as evacuation information.
Throughout the country, in particular on September 1, Disaster
Reduction Day, many disaster reduction drills and outreach activities
are conducted to prepare for future disasters.
(b) Community-based Disaster Reduction Activities and Disaster
Reduction Education
It is important to improve the general public’s awareness of disasterrisks and disaster reduction at the community level so that everyone cantake the appropriate actions when a disaster strikes. Some communities
organize activities designed to increase public understanding of hazard
maps and activities to create community-based disaster risk reduction
maps. These include “town watching” activities in which people
actually go around the town they live in and identify its disaster risks,and hold workshops on disaster risk reduction. Such activities raise
local residents’ awareness of disasters and disaster reduction, lead tosuggestions for improving the community’s vulnerabilities, andcontribute significantly to improving the disaster reduction capabilitiesof the community.
To promote disaster reduction education, education materials werecreated and distributed in 8 Asian countries, in which the tale of“Inamura no Hi” (“Fire of Rice Sheaves”) based on an actual disaster
experience in Wakayama Prefecture was translated into local languages.

Framework/Mechanism of International Cooperation for Disaster Risk Reduction and Japan’s Contribution25

October 2009, Incheon, Korea<Case file 4> Flood Hazard Mapping in 8 Asian Countries
Asian Monsoon areas, especially East and Southeast Asian areas
experience numbers of floods each year. Many human lives and propertiesare lost due to the floods. In order to reduce damage caused by floods, built
infrastructures like river dikes or reservoirs are very effective. On the other
hand, non-built infrastructures such as “Flood Hazard Map”, which can offer
information on past flood track records, flood estimation, evacuation route,evacuation place, etc. to the residents, are also important. Effectiveness ishigher and quicker especially in areas where built measures are not yet inplace.
From such viewpoint, in 2006, the Government of Japan implemented
a training course called “Food Hazard Mapping” to technical managers andengineers involved in flood or river management in the public sector from 8
countries in East and Southeast Asia (Cambodia, China, Indonesia, Laos,
Malaysia, Philippines, Thailand, and Vietnam). It is expected that after the
training, knowledge and technique will be spread in each country, and flood
damages in each areas are mitigated through development of flood hazard
map.

(7)
Some information on Japanese government offices and institutions
related to disaster reduction are as follows:
Cabinet Office; http://www.cao.go.jp/index.html (Japanese)
http://www.cao.go.jp/index-e.html (English)
Ministry of Land, Infrastructure, Transport and Tourism;
http://www.mlit.go.jp/ (Japanese)
http://www.mlit.go.jp/index_e.html (English)
National Research Institute for Earth Science and Disaster Prevention;
http://www.bosai.go.jp/index.html (Japanese)
http://www.bosai.go.jp/e/index.html (English)
4. CONCLUSIONSIn the above sections, the author tried to have an overview of overall
framework of international cooperation for disaster risk reduction and therelated process that has been taken, regional cooperation mechanism
particularly in the Asian region, as well as the efforts so far undertaken by
Japan. Next year, 2010, will be the mid- term year of the HFA, and at thisjuncture, the author sincerely hopes that there will be a renewed attention to
integrate efforts at various levels into a concerted international and regional
cooperation.

26

New Technologies for Urban Safety of Mega Cities in Asia

DESIGNING RC STRUCTURES FOR FIRE
SAMARTH P. RAMDASIFormer Graduate Student, Dept. of Civil Engineering, IIT, Kanpur, India
imsaneth@gmailcom
SUDHIR MISRA
Professor, Dept. of Civil Engineering, IIT, Kanpur, India
sud@iitk.ac.in
P.S. GHOSHDASTIDAR
Professor, Dept. of Mechanical Engineering, IIT, Kanpur, India
psg@iitk.ac.in

ABSTRACTReinforcing bars within concrete need to be protected from hightemperatures that may occur outside in the event of a fire, etc. and the coverconcrete serves that purpose. Design codes usually place an empirical limit
on minimum cover thickness for a certain level of fire resistance.
In order to establish a rational basis for determining the concrete
cover thickness, an effort has been made in this study to estimate thetemperature variations within concrete for different fires in a model
reinforced concrete (RC) chamber using MATLAB. The analysis has carriedout in two steps – (a) determination of the environmental (gas) and surface
temperature of concrete using the compartment fire model proposed byPettersson et al. (1976), and, (b) studying the temperature variation withinconcrete based on 1-d transient heat conduction using the explicit finite
difference method. The geometric and material properties of the RC
chamber were varied, and the required cover obtained for different‘permissible’ levels of temperature at the reinforcement level.
Results showed that the parameters like openings area, room size, andmaterial properties significantly affect the temperatures in the chamber andalso within concrete. For example, increasing the compartment size from
4x5x3.1 (At=95.8 m2) to 5x6x3.1 (At=128.2 m2), can reduce the firetemperature by 1640 C (about 11%). Similarly, lowering of compartment
openings can reduce the fire temperature by 1250C though it also has theeffect of increasing the duration of fire by about 8 minutes. Thus, attention
to these parameters can help reduce the cover thickness requirement.

1. INTRODUCTION
Concrete is a composite material widely used material in the construction ofvarious kinds of structures. It acts as a load bearing material in building27

October 2009, Incheon, Korea

components and the cover concrete protects the reinforcement within fromthe harmful effects of environmental action such as chloride attack and fire.
It has been reported that reinforced concrete (RC) structures lose theirability to carry loads after exposure to higher temperatures due to the effectof high temperatures on both – steel and concrete (Harmathy, 1970;
Takeuchi, 1993). Though concrete is poorer conductor than steel, sustained
high temperature at the surface, as can be expected in a fire, leads toprogressive heating of the inner layers of concrete, and also exposes
reinforcing bars to elevated temperature, depending upon factors such as theduration of fire, thickness and properties of the cover concrete, etc. Indeed
the properties of concrete are also known to undergo significant changes
upon exposure to high temperatures. Effort in this study is directed to study
the effect of outbreak of fire in an RC chamber with openings and a certain
amount of fuel on the temperature of the environment in the chamber (gastemperature) and the variation of temperature within the concrete.

2. MODEL DESCRIPTION
2.1 Basic description
Figure 1 gives a diagrammatic representation of the RC chamber usedin the model here. It can be understood that in the event of a fire in thechamber, the temperature (of the air) within the chamber will increase,which, in turn, will cause the surface temperature of concrete to also
increase, depending upon the fire temperature and surface heat transfer
coefficient. Further, an increase in the surface temperature will have theeffect of increase in the temperatures within the concrete depending upon
the properties of the concrete, including conductivity, etc.

qw
qw

qL

q c:
q L:
q w:

qR

qc

qR:
qB:

qw

heat
releaseddue
tocombustion
convection heat loss
heat loss by conduction
through all the walls of thechamberradiation heat loss
heat stored in the gas volume(neglected, not shown in thisfigure)Figure 1: Compartment fire heat balance
In present study, for the first part, i.e. computation of the timetemperature variation of the gas within the chamber and subsequently thesurface temperature of concrete, the compartment theory concepts and amathematical model available in the literature have been used (Harmathy

28

New Technologies for Urban Safety of Mega Cities in Asia

1972; Pettersson, 1976) have been used. The model discussed takes into
account the affect of parameters such as the dimensions of the chamber, fuelload within the chamber, size and location of openings and thermal
characteristics of the compartment boundaries (Kawagoe, 1958). It may be
noted that all walls of the chamber have been assumed to be made ofconcrete and have the same thickness. For the second part, the formulation
is based on the explicit finite difference method using 1-d heat conduction.
2.2 Problem formulation
As mentioned above the basic mathematical formulation adopted isthat developed by Pettersson et al (1976). The heat balance in the event offire in the RC chamber shown in Figure 1, can be represented as:
qc = qL + qw + qR + qB……….(1)In this study, while qB has been assumed to be small and neglected,
other terms have been evaluated and finally the gas temperature in thechamber calculated using the following equation (Patterson, 1976).
……….(2)where,
Cp = Specific heat of the gas in KJ/(Kg.K)
To = Outside temperature in K
Aw = Area of the opening in m2
H = Height of the opening in m
At = Total surface area of the room in m2
hi = Heat transfer coefficient of the wall in KW/m2K
Ti = Inside wall surface in K
σ = Stefan-Boltzmann constant KW/m2K4
εf =Emissivity
Tg =Gas Temperature in K
In the next step, 1-d transient heat conduction equation
has been used to calculate the temperature variation within the chamber
walls using a formulation based on explicit finite difference method’. The
approach divides the wall into several slices, each measuring Δx, andcalculates the temperature at each grid point lying at the interface of theslices at time ‘P+1’, for the given thermal conductivity K, specific heat C
and density ρ using the following relationship.
……….(3)where,

Designing RC Structures for Fire,

, Δt and Δx are the time and distance intervals

29

October 2009, Incheon, Korea

At the inside and outside surfaces of the compartment boundaries,
surface temperature at point ‘1’ and ‘N’ is obtained using convection
boundary condition and using the image point technique.
……….(4)……….(5)where, β and β’ are given by as follows:

h and h′ are the surface heat transfer coefficients (Pettersson, 1976). The
time step, Δt, has been so chosen as to ensure that the coefficients ofandare always positive to ensure numerical stability.

3. RESULTS AND DISCUSSION
3.1 Compartment used
Notes:i.
All dimensions in meter
1
ii.
Thickness of all chamber
wall/slabs taken to be 160mm
iii.
Ambient temperature outsidechamber: 25 0C

0.9
3.1
2.1

0.9

0.9

4
5

Figure 2: Model chamber used for calculations
Figure 2 shows the details of the model chamber used in the study,
including the dimensions, locations of openings, etc. Table 1 gives thedetails for the different relevant parameters. The results obtained using themodel described above are given in the following paragraphs.
3.2 Variation of Tg with time
Effect of total area of the compartment (At): Effect of room size, in termsof the total inside surface area of concrete walls on maximum gas
temperature (Tgmax) has been shown in Figure 3, keeping the opening sizeand height constant at 2.79m2 and 1.75m, respectively. The gas temperature
has been calculated at three levels of fuel in the room – 300 kg, 500kg and1000 kg, and varying the total surface area At from 10 m2 to 1000 m2.

30

New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Assumed parameters
Parameter
Unit
Value
Remarks
CP
KJ/Kg
1.01
Specific heat of airσ
KW/m2 5.67x10-11 Stefan-Boltzmann constant
KW/mConductivity of concrete in theK
1.7x10-3
K
walls of the chamber
C
KJ/Kg
0.836
Specific heat of concrete
3
ρ
Kg/m
2300
Density of concrete
Δx
m
0.010
Grid spacing
Δt
sec
0.4
Time step

Figure 3: Variation of Tg max
with total surface area ‘At’ for aconstant ventilation factor

Figure 4: Variation of Tg
with At for different AwH1/2
for a constant fuel load

It can be seen from Figure 3 that Tgmax decreases as size of room
increases with a relatively small impact of the amount of fuel in the room.
The result can be attributed to the fact that the ventilation factor AwH1/2 hasbeen kept constant in this study, i.e., flow of fresh air into the room is highly
restricted. Thus, for an increase in the size of the room, the effect is simply
the lowering of the maximum temperature reached in the event of fire. It isalso interesting to note that the effect of the fuel load is reduced at both
extremes – for small and large values of At. Figure 4 shows the variation of
Tgmax with At for a fixed fuel load of 500 Kg for different ventilation factors.
It can be seen that the trend is almost similar to Figure 3 and the variation
can be taken as linear except at very high or very low values of At.
Effect of varying area (Aw) and the height (H) of opening: The opening
size is an important parameter in determining the gas temperature, as an
opening serves the dual role of (i) facilitating inflow of fresh air and oxygen,
which are required to sustain a fire, and, (ii) serving as an exit for the hotgases resulting in heat loss through convection. In this study, the opening
size (Aw) has been varied from 0.5 m2 to 5 m2, keeping all other parametersconstant, and Figure 5 shows the results obtained. The height of the opening

Designing RC Structures for Fire

31

October 2009, Incheon, Korea

H, the total surface area At of the compartment and the fuel load has also
kept constant at 1.75m, 95.8 m2 and 500kg, respectively.
Now, as opening area increase from about 0.5 to 5m2, it can be seenthat the Tg increases by about 600ºC. This increase can be justified on
account of the fact that for larger openings, there is ample flow of fresh air(along with oxygen) aiding the burning and heat release. It may also bementioned that larger openings also lead to greater heat loss through them. It
should also be noted that the opening size also has an impact on the durationof the fire, and this aspect has dealt with elsewhere (Ramdasi, 2009).

Figure 5: Variation in Tgmax
with respect to opening size Aw

Figure 6: Variation in Tgmax withrespect to height of the opening H

Similarly, the height of the opening is also an important parameter,
and the results obtained by varying the height between 0.5m and 4m areshown in Figure 6. It can be seen that increasing height of ventilation
opening, could cause significantly higher values Tg.
3.3 Variation of temperature within concrete
From an engineering point of view it is important to know thetemperatures reached at the location of the reinforcing bars to decide theresidual strength of the steel bars and the repair strategy (Hemraj, 2009).
Though largely related to issues such as the amount of fuel, duration of fire,
etc. the variation of temperature within concrete is also affected by thethermal properties of concrete – conductivity and specific heat. Thoughmore rigorous analysis should take into account changes in these properties
as the temperature within rises, in the present analysis, these values havebeen taken to be constant (temperature invariant).
Thermal conductivity of concrete (K): Thermal conductivity of concrete is
known to vary between 1.2 and 1.9 W/m K (Lie, 1978), and affects thevariation of temperature within concrete. The effect of conductivity on the

32

New Technologies for Urban Safety of Mega Cities in Asia

maximum temperature profile within the concrete wall is shown in Figure 7
for a constant specific heat and density. The results for two durations of fireshow that as the K, the maximum surface temperature increases. As the
conductivity goes down, dissipation of heat through conduction decreases,
increasing the gas temperature and surface temperature within thecompartment (Harmathy, 1972). In other words, though the maximum
surface temperature of low conductivity concrete increases, the maximum
temperature within the concrete decreases. Similarly, in cases when the K is
high, the concrete absorbs more energy from the environment, and though
the gas temperature (and the surface temperature) goes down, the maximum
temperature within concrete tends to increase (Ramdasi, 2009).

Figure 7: Maximum temperature profile for different conductivity value fordifferent durations.
Specific heat (C): Specific heat of the material is amount of heat required toraise temperature of unit quantity of material by a unit degree oftemperature. Thus, for the same amount of heat, a higher rise in temperature
may be expected in materials with a lower specific heat, than in a material
with higher specific heat. Figure 8 shows the variation in maximum
temperature profile within concrete for different values of specific heattaken from the literature. It can be seen that there is a steady increase inmaximum temperature values for decreasing specific heat.

Figure 8: Maximum temperature profile within concrete wall for different
specific heat value for full duration.

Designing RC Structures for Fire

33

October 2009, Incheon, Korea

4. DETERMINATION OF CONCRETE COVER THICKNESS
Codes generally ‘prescribe’ different levels of concrete cover for varying
durations of fire (IS 456, 2000). However, more than such an empiricalvalue, a rational design approach should be based on fixing a criticaltemperature at the reinforcement level, which should not be exceeded in theevent of fire, and then determining the required cover based on theproperties of concrete, duration of fire, etc. Now on the basis of the analysis
discussed above, Table 2 presents the results for the required levels of cover
thickness for the model structure given in Figure 1 for different criticaltemperature at the reinforcement location, depending on the characteristics
of compartment.
Table 2: Estimates of required cover thickness for the model structure
Fire duration(hours)12
34Required cover (in mm) for different critical temperatures
400ºC
500ºC
600ºC
44
37
32
68
59
51
88
76
67
106
92
80

5. CONCLUDING REMARKSWith special concretes with properties quite different from conventional
concrete being used often in very critical structures susceptible to fire, it isimportant that rational methods be adopted to determine the cover required
based on the design fire, the actual geometric design and material properties,
and the ‘permissible’ critical temperature at the reinforcement level. The
computations presented highlight the importance of these parameters andshow that the present specifications need to be re-evaluated.
REFERENCES

Harmathy, T.Z. (1972); A New Look at Compartment Fires, Part II. Fire
Technology,Vol. 8 (4), 326-351.
Harmathy, T.Z. (1970); Thermal properties of concrete at elevated temperature.
ASTM Journals of Materials, 47-74.
IS:456 (2000); Indian Standard for plain and reinforced concrete -Code of practice(fourth revision). Bureau of Indian Standards, New Delhi.
Hemraj, B. (2009); Effect of heat on thermo-Mechanically treated reinforcing steel
bars. M Tech Thesis submitted to IIT Kanpur
Kawagoe, K. (1958); Fire Behaviour in Rooms. BRI Report No.27, Building ResearchInstitute, Ibaraki-Ken, Japan.
Lie, T.T. (1978); Calculation of the Fire Resistance of Composite Concrete Floor andRoof Slabs. Fire Technology Vol.14 (1), 28-45.
Pettersson, O., S. Magnussen, and J. Thor. (1976); Fire Engineering Design of Steel
Structures. Swedish Institute of Steel Construction, Stockholm.
Ramdasi, S.P. (2009); Modeling reinforcement temperatures in RC structures
susceptible to fires. M Tech Thesis submitted to IIT Kanpur
Takeuchi, M., M. Hiramoto, N. Kumaga, N. Yamazaki, A. Kodaira, and K. Sugiyama.
(1993); Material properties of concrete and steel bars at elevated temperatures. Elsevier
Science publishers.

34

New Technologies for Urban Safety of Mega Cities in Asia

CLOSING SESSIONALOS AND SENTINEL ASIA FOR
DISASTER MONITORING
Prof. Haruhisa Shimoda
Director, Tokai University Space Information Center
Deputy Director, Tokai University Research & Information Center
President of Commission 8 (Remote Sensing Application),International Society for Photogrammetry and Remote Sensing
smd@keyaki.cc.u-tokai.ac.jp

ABSTRACTALOS was launched on 24th Jan. 2006 from Tanegashima Space
Center by H2-A launcher. Satellite is operating well and all 3 sensors onboard are also operating well. Commissioning phase ended at the beginningof May 2006, calibration and validation phase ended at October 2006 andALOS has been full operational from the middle of October 2006.
The mission of ALOS is to provide sufficient data, which enable togenerate 1 to 25,000 scale base maps all over the world as well as disastermonitoring. ALOS carries 3 sensors. One is an L band synthetic apertureradar called PALSAR (Phased Array L band Synthetic Aperture Radar).
PALSAR has an active phased array antenna, and has many capabilities,
like variable incidence angle, variable resolution, scan SAR capability andmulti polarization capability.
ALOS has two optical sensors, i.e., AVNIR-2 and PRISM. AVNIR-2(Advanced Visible and Near Infrared Radiometer) is a follow on of AVNIRon ADEOS and has 4 bands with 10 m resolution. PRISM is a panchromatic
sensor with 3 telescopes, which will enable PRISM to take 3 direction (nadir,fore and aft) stereo pairs simultaneously. The resolution of PRISM is very
high (2.5m) with rather narrow swath (35km). In addition to the stereo
capability which will provide global DEM data, PALSAR will be also usefulfor the evaluation of global tree stand biomass.
For the disaster monitoring, ALOS is a part of two international
projects, i.e. the International Charter "Space and Major Disasters", andSentinel Asia. International Charter aims at providing a unified system ofspace data acquisition and delivery to those affected by natural or manmade disasters through Authorized Users. Each member agency has
committed resources to support the provisions of the Charter and thus ishelping to mitigate the effects of disasters on human life and property.
Sentinel Asia is a "voluntary and best-efforts-basis initiatives" led by
the APRSAF (Asia-Pacific Regional Space Agency Forum) to share disaster
information in the Asia-Pacific region on the Digital Asia (Web-GIS)
platform and to make the best use of earth observation satellites data fordisaster management in the Asia-Pacific region.
ALOS has been contributing to these two projects many times during
its operational phase.

35

October 2009, Incheon, Korea

ALOS follow on is now planned in JAXA. They are ALOS2 and ALOS3.
ALOS2 will carry an improved L-band SAR with high spatial resolution (upto 1x3m GSD), while ALOS3 will carry also high resolution optical sensor(0.8m PAN and 2.4m XS GSD).

36

New Technologies for Urban Safety of Mega Cities in Asia

EARTHQUAKE COUNTERMEASURESFOR SAFER FUTURE IN KOREA
WAON-HO YI
Director, National Institute for Disaster Prevention, Korea
whyi1208@nema.go.kr

ABSTRACTDue to the great earthquakes which occurred recently in neighboring
countries, such as the 1995 Hyogoken-Nambu Earthquake with more than
6,500 fatalities in Japan, the 1999 Chi-Chi Earthquake with more than
2,500 fatalities in Taiwan, and the 2008 Sichuan Earthquake with more than
69,000 fatalities in China, the importance of the future earthquake
preparedness measures is highly recognized in Korea. Lesson from theHyogoken-Nambu Earthquake in 1995, Korea Government has added
earthquake as the disaster items in the revised "National Disaster
Countermeasures Act" and established 1st Earthquake Disaster
Countermeasure Plan. And Korea Government has made the efforts forearthquake hazard mitigation including 1st~3rd Earthquake Disaster
Countermeasures Plan focused on setting the seismic performance level,
legal system maintenance, prevention, preparation, response, recovery and
Earthquake Disaster Countermeasure Act enacted in Mar. 28, 2008. In thispaper, proceedings of Earthquake Disaster Countermeasure Plan in Korea
from 1995 to 2009 is introduced and discussed.

1. INTRODUCTION
The devastating 1995 Hyogo-Nambu Earthquake occurred in Japan withmore than 6,500 fatalities, 1999 Chichi Earthquake occurred in Taiwan withmore than 2,500 fatalities and 2008 Sichuan Earthquake occurred recently in
China with more than 69,000 fatalities in China awakened the publicconcern about the possible earthquake disaster in Korea.
Many seismologists pointed out that a disastrous earthquake could occur at
any time. After the Hyogoken-Nambu Earthquake in 1995, Korea
Government has added earthquake as the disaster items in the revised"National Disaster Countermeasures Act" and established 1st Earthquake
Disaster Countermeasure Plan. And Korea Government has made the efforts
for earthquake hazard mitigation including 1st ~ 3rd Earthquake Disaster
Countermeasures Plan and Earthquake Disaster Countermeasure Act
enacted in Mar. 28, 2008.

37

October 2009, Incheon, Korea

A comprehensive earthquake disaster countermeasures plan was drawn up
to establish the mitigation countermeasures, emergency response
countermeasures, and rehabilitation countermeasures of related agencies in
1998.
In this paper, historical and recent earthquakes mainly occurred in Korea
and 1st ~ 3rd phase of Earthquake Disaster Countermeasure Plan are
introduced. Also, main research and development project plans regarding to
the Earthquake Disaster Countermeasure Plan are discussed.

2. STATUS OF THE EARTHQUAKE OCCURRENCE IN KOREA
It is well known that Korea for the earthquake is relatively safer thanneighboring countries located in circum Pacific zone such as Japan and
China as shown in Fig. 1 (http://www.seismo.ethz.ch/gshap/eastasia).
Furthermore, recent hazardous natural disasters occurred in Korea havebeen mainly caused and governed by meteorological and hydrologicalphenomena.

Figure 1: Seismic Hazard Map for Eastern Asia
However, it is pointed out that the Korean peninsula is not free from thedestructive earthquakes according to the historical earthquake records.
Historical earthquake records from the historical literatures shown in Fig. 2
indicate that a number of earthquakes occurred during the 15-18th centuries
and the seismicity in 20th century increased.
In addition, frequency of earthquakes is increased steadily as shown in Fig.
3, although a felt earthquake more than 4.0 of earthquake magnitude is notincreased. And also, due to the reason regarding to the Korean peninsula
located in border line of Pacific Plate and records of historical earthquake
damage, it is needed to prepare the future earthquake.

38

New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Time Distribution of Earthquake Occurrence in Korea
60
Total number of the earthquake occurrence49

Number of the earthquake occurrence over the 4.0
of magnitude

50
e
c
n
e
rr
u 40
c
c
O
e
k
a
u
q 30
th
r
a
E
f
o
r
e
b 20
m
u
N

50

42

43
39

42
39

38
37
32
29

29
26

25
23

22
16 15

15

15

21

19

20 19
16

27

15

13
11

10

6

6

0
78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08
Year of Earthquake Occurrence

Figure 3: Earthquake Activities (1978~2007)

Table 1 shows the list of representative earthquakes and tsunami affected
damages in Korea in 20th Century.
As shown in Table 1, it is found that most of economic losses are caused bytsunamis. However, casualties from earthquake are relatively less thaneconomic losses, because of the earthquake characteristics with short period
and sustained time. However, based on the fact that the Tangshan
earthquake in 1976 showed that the intraplate seismicity can cause the large
disasters, and also several faults are founded in Korea. So that reasons,many researchers carefully attempt to propose that the Korea is not the safearea from the earthquake disaster.

Earthquake Countermeasures for Safer Future in Korea

39

October 2009, Incheon, Korea

Table 1: Earthquakes and Tsunamis affected damages in Korea
Casualties
Earthquake/
Mag.
TsunamiTotal Death Injured Missing
Ssanggyesa
Earthquake(1936.7.4)
TsunamiCaused by
Niigata
Earthquake(1964.6.16)
Mt. Songni
Earthquake(1978.9.16)

Economic Losses

4

0

4

0

- Damages in Building : 113 (Collapse : 3)
- Damages in Cultural Buildings including
Ssanggyesa

7.5

0

0
(473
in
Japan)

00- Wave Height : 32cm(Pusan), 39cm (Ulsan)

5.2

0

0

0

0

-

5.1

- Economic Losses : 301million won- Damages in Building :100 (Cracks in 1,000 buildings)- Hongju Castle was collapsed- Broken Windows :500 windows in Official Building-Economic Losses :370million won(Wondeok Port : 243,
Samcheok Port 93, Ulleungdo 21,
Uljin 6million won)
- Damages in Building :44(Collapse : 1, Flood : 21)- Damages in Ship : 81

Hongseong
Earthquake(1978.10.7)

5.0

2

0

2

0

TsunamiCaused by
Earthquake in
Middle East
Sea
(1983.5.26)

7.7

5

1

2

2

TsunamiCaused by
Earthquake inSouthwestern
Seaway of
Hokkaido(1993.7.12)

7.8

0

0

0

0

Yeongwol
Earthquake(1996.12.13)

4.5

0

0

0

0

Uljin Offshore
Earthquake
5.2(2004.5.29)

0

0

0

0

Fukuoka
Earthquake(2005.3.20)

7.0

0

0

0

0

-The elevator was temporarily stopped in
Pusan-Unloading operations stopped 30 minutes in
Pusan port

Mt. Odae
Earthquake(2007.1.20)

4.8

0

0

0

0

- Damages in Building : Cracks were appearedin old URM buildings- Economic Losses : 390million won- Damages in Ship : 35
- Fishing-nets : 3,000

3. EARTHQUAKE DISASTER COUNTERMEASURE PLAN
Destructive Hyogoken-Nambu Earthquake in Japan affected huge transitionof recognition for the earthquake countermeasures in Korea. With this as a
momentum, Korea Government has added earthquake as the disaster itemsin the revised "National Disaster Countermeasures Act" and established 1stEarthquake Disaster Countermeasure Plan. In this chapter, process of 1st ~3rd Earthquake Disaster Countermeasures Plan is discussed.

40

New Technologies for Urban Safety of Mega Cities in Asia

3.1 The first phase of earthquake disaster countermeasure plan
In January 27, 1995, the 1st Earthquake Disaster Countermeasure Planof Korea Government is established through the conference participated
relevant ministries and experts. In this 1st Earthquake Disaster
Countermeasures Plan, setting the seismic performance level, legal system
maintenance, and preparing of Earthquake Disaster Countermeasure Act
were mainly focused on. As a consequence, direction of the propelled goalis planned as follows.
- Propelling the ACT for the Earthquake Prevention Countermeasures- Establishment of practical plan for the earthquake disaster mitigation- Reducing casualties from system maintenance of rescue and relief- Strengthening the relationship of each ministry and expert group- Promotion the PR for the consciousness of earthquake disasters- Strengthening and developing the seismic design code and provision- Encouragement the R&D for earthquake damage mitigation
From the 1st phase of Earthquake Disaster Countermeasure Plan,
adaptation of the seismic design is widened for the 20 kinds of facilities.
And seismic design provisions are re-established and applied. Through theevaluation of the 1st phase of Earthquake Disaster Countermeasure, the 2ndphase is established with modification and complement on December 2005.
3.2 The second phase of earthquake disaster countermeasure plan
It is highly recognized for the consciousness of the earthquake andtsunami damages from the Fukuoka earthquake which are occurred on
March 20, 2005. After the Fukuoka earthquake, Prime Minister Council
decided to establish the 2nd phase of Earthquake Disaster Countermeasure
Plan. And 2nd phase of Earthquake Disaster Countermeasure Plan (tentative)
is reported on April 12, 2005. As consequences, a special committee
regarding to the earthquake disaster prevention for the various
improvements is set up. After building the road map for 5 years R&D andpolicy plan, propelling of the 2nd phase is started. Directions of the propelledgoals as shown in Fig. 4 are planned as follows.
- Enactment and maintenance of ACT for the earthquake disastermitigation.
- Complementation for the early response system of improvement of
the observation and alert system for the earthquake and tsunami.
- Developing and strengthening the education and training programfor rapid response of the earthquake disaster.
- Building the earthquake disaster mitigation-based foothold including
strengthening the seismic provision and developing the earthquake hazard
map.

Earthquake Countermeasures for Safer Future in Korea

41

October 2009, Incheon, Korea

From the 2nd phase of Earthquake Disaster Countermeasure Plan, theAlert System for the earthquake/tsunami and the Earthquake Disaster
Management System were successfully developed.

Figure 4: 2nd Phase of Earthquake Disaster Countermeasure Plan
In addition, Earthquake Disaster Countermeasure Act (Act No. 9001)
that consists of 8 chapters and 29 articles enacted in Mar. 28, 2008 andenforced in Mar. 25, 2009. From the promulgation of Earthquake Disaster
Countermeasure Act, related enforcement decree (Presidential Decree No.
21362) that consists of 8 chapters and 16 articles were enacted and enforced
in Mar. 25, 2009. And Enforcement ordinance (Ordinance of Ministry
Public Administration and Security No. 72) that consists of 5 articles wereenacted and enforced in Mar. 26, 2009.
3.3 The third phase of earthquake disaster countermeasure plan
To keep and make safer Korea for the future earthquake disaster, the
3rd Earthquake Disaster Countermeasure Plan is propelled from 2009. In this
3rd phase from 2009 to 2013, it is mainly focused on the 6 kinds of subject
including (1) the seismic retrofitting for the existing structures adopted nonseismic design, (2) development and application of seismic hazard map, (3)development of earthquake notification and response system for the rapid
response, (4) development of tsunami countermeasures, (5) strengthening
the public education and training related to the earthquake disasterprevention and (6) strengthening and maintenance for the legislation and theorganization dedicated to the earthquake will be mainly propelled. In thisEarthquake Disaster Countermeasure Plan, it is established by 3 kinds ofmain tasks these are divided by 8 kinds of subsidiary tasks. And 8 kinds ofsubsidiary tasks are divided by total 24 kinds of tasks. From 8 kinds of42

New Technologies for Urban Safety of Mega Cities in Asia

subsidiary tasks, R&D project are being partially implemented in this year
2009 with 58 detailed projects. The 3 kinds of main tasks including 8 kindsof subsidiary tasks are as follows.
(1) Seismic Performance Level and Legal System Maintenance- Establishment of integrated seismic performance level- Maintenance of Institutionalized organization for effective promotion
regarding to the propelling of Earthquake Disaster CountermeasurePlan(2) Prevention and Preparation- Advancement of observation system for the earthquake/tsunami- Development and utilization of the earthquake hazard map andactive faults map- Re-establishment of seismic design provision and propelling ofseismic retrofitting for existing facilities- Establishment of tsunami disaster countermeasure- Strengthening of the public education and training program to thenation related to the earthquake disaster prevention(3) Response and Recovery- Development of rapid response system for earthquake occurrence

4. Earthquake Disaster Management System
For the prompt damage estimation according to the earthquake occurrence,
Earthquake Disaster Management System (EDMS) was developed in 2006.
As development of EDMS shown in Fig. 5~6, it is possible to inform the
National-wide intensity map, estimation results of the casualties anddamages in structures.

Figure 5: Precedence and Advanced Research on EDMS

Earthquake Countermeasures for Safer Future in Korea

43

October 2009, Incheon, Korea

Fig. 5 shows the development process including the precedence researches
which was established and advanced research which will be establishing on
EDMS. In 2008 research and development, further development of damage
estimation of lifelines and support system concerning with emergency
response was surveyed and applied to the EDMS. And 3rd phase of
Earthquake Disaster Countermeasures Plan, additional implementation of
the system’s advancing including the improvement of accuracy andextending the items to damage estimation shown in Fig. 6 will be propelled.

Figure 6: Advancing the EDMS

6. CONCLUSION
It is true that Korea is relatively safer than neighboring countries for thedisastrous earthquake and also recent hazardous natural disasters occurred in
Korea have been mainly caused by meteorological and hydrologicalphenomena. However, frequency of earthquakes is increased steadily, andalso, Korean peninsula located in border line of Pacific Plate. For thatreason, it is urgently needed to prepare the future earthquake. Lessons fromdisastrous earthquakes cases, all passions and efforts for earthquake disastermitigation will be devoted with Earthquake Disaster Countermeasures Plan.

REFERENCES
Yi, W. H., 2009, Earthquake Disaster Management Policies in Korea,
International Seminar on Disaster Prevention Technology 2009, 57-95
National Emergency Management Agency, 2009. Earthquake Disaster
Countermeasure Plan, 204.
National Emergency Management Agency, 2009. Disaster Management for
60 years, 580.

44

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 1

RESEARCH ON DIGITIZED EMERGENCYRESPONSE PREPLAN FOR PUBLIC
SAFETY IN CHINA
WEICHENG FAN
Center for Public Safety Research, Tsinghua University, Beijing, China
State Key Laboratory of Fire Science,
University of Science and Technology of China, Hefei, China
wfan@tsinghua.edu.cn
GUOFENG SU
Center for Public Safety Research, Tsinghua University, Beijing, China
sugf@tsinghua.edu.cn
HONG HUANG
Center for Public Safety Research, Tsinghua University, Beijing, China
hhong@tsinghua.edu.cn

ABSTRACT
Public safety is threatened by numerous disasters and accidents whichlead to tremendous loss of life, damaged infrastructures and lifelines,
collapsed buildings and houses, and unstable society, etc. It is the
responsibility of government and related departments to give a fast andefficient response to this kind of public accidents. Emergency response
preplan is the accident control and disaster relief plan which is made by thegovernment or companies beforehand to reduce the unexpectedconsequence of the public safety related accidents based on the hazard
source assessment and disaster forecast analysis. The preplan is theguideline for the emergency response and rescue activity. In this paper, theconcept of the emergency response preplan is introduced. Especially the
research on digitized emergency response preplan in China is presented. As
an example, the digitized emergency response preplan for fire safety ofBeijing Olympic venues is shown here. It can give the strong support for
arrangement of action and rescue of extinguishing activity, and provide anadvanced means of strategy, technical and psychologist training for
firefighters, and enhance the comprehensive management of fire emergency
response.

1. INTRODUCTION
In recent years, public emergency accidents occur frequently due tourbanization, globe climate change, informationized society, etc. Such as,
recent H1N1 influenza, Wenchuan Earthquake in China, Cyclone Nargis in
Myanmar, SARS rampant in China, Sumatran earthquake and its resultant

45

October 2009, Incheon, Korea

tsunami, Hurricane Katrina in USA and 911 terrorism in USA, etc. These
accidents all lead to tremendous loss of life, damaged infrastructures andlifelines, collapsed buildings and houses, and unstable society. It is the
responsibility of government and related departments to give a fast andefficient response to this kind of public accidents.
After suffered many public accidents, China government recognized theimportance of emergency response to public accidents and contributes great
effort to promote emergency management. On January 8, 2006, The China
State Council issued the national plan on emergency response (China StateCouncil, 2006). The National Emergency Response Preplan aims to increase
the government's capability to protect public safety, deal with unexpected
accidents, minimize the losses of the accidents, maintain social stability, andpromote the harmonious and sustainable development of the country. When
the National Emergency Response Preplan is announced, all provinces,autonomous regions and municipalities begin to make their own emergency
response preplans, indicating a basic emergency response framework has
been set up in China.
In this paper, the concept of the emergency response preplan is introduced.
Especially the research on digitized emergency response preplan in China ispresented. As an example, the digitized emergency response preplan for fire
safety of Beijing Olympic venues is shown here.

2. CONCEPT OF EMERGENCY RESPONSE PREPLAN
2.1 Text and digitized emergency response preplan
Emergency response preplan is the accident control and disaster relief
plan which is made by the government or companies beforehand to reduce
the unexpected consequence of the public safety related accidents based on
the hazard source assessment and disaster forecast analysis. The preplan is
the guideline for the emergency response and rescue activity (Fan and Su,
2005).
Usually, these preplans are in the form of text saved in security boxes
or electronic medium. Once public accident occurs, the procedure andtreatment formulated by these preplans are the major base of the first action.
Generally, the hypotheses of the progress process and consequences of theaccidents are used when making these preplans. However, because theactual situation usually is very complex, it is impossible that the hypotheses
are consistent with the actual accident progress. Therefore, the emergency
response preplan cannot be directly used to deal with the public accidents.
The text preplan must be revised and amended based on the pastexperiences, the past cases, on-site situation and theory models to form theactual response action plan for dealing with the public accidents. Because

46

New Technologies for Urban Safety of Mega Cities in Asia

coupled with the science model, decision-making technology and caseanalysis result, the actual response action plan is called intelligent plan.
Series analysis processes, including the introduction of the past cases,
experiences, models, on-site information and database, etc, are needed forthe generation from the text preplan to the intelligent plan. If we make thekey points in the text preplan structured, and associate, link and embed therequired past case libraries, knowledge database, model database to the
preplan through some specific ways, then we can establish a new type of
preplan based on the computer information system (Yuan et al, 2007).
This preplan includes not only the procedures and methods
regularized by the text preplan, but also the required information in thegeneration process from the text preplan to the intelligent plan. The
information include the spatial structure, experts, models, cases libraries,
knowledge, emergency resources and other information based on the
response platform. This preplan can shorten the generation time from theemergency response preplan to emergency response plan, it is more efficientto play a role of the preplan and implement training exercises and update of
the preplan. This new type preplan is called digitized preplan. When public
accident occurred, based on the accident information and other related data
information, the digitized preplan system will rapidly provide a direct andefficient action plan (intelligent plan) and adjust the action plan in real time.
Figure 1 shows the differences between the text and digitized preplan.
Digitized
Dynamic
Plan
Digitized
Preplan

Text Static
Preplan
Text
Plan

Scientific law of disaster occurrence
and development

Hypothetic
disasterConstitution reference

ComplicatedInquiry function

Simple and fast

Static text

Visual effects

Visual+ Dynamic+Audio

Little and fixed

Data information

Description incharacters

Integrated supporting

Strong comprehensive supporting
GIS-based resource allocationdifficulty

Expansion and update

Easy and Extendable

Vast and allocable

Figure 1. The comparison between text preplan and digitized preplan
for emergency response
2.2 Functions of digital emergency preplan
Digitized preplan system is established to satisfy the emergency
response to the public accidents. The aim is to rapidly and efficiently
accomplish the emergency rescue actions. Digital emergency preplan has
following functions.
1) Emergency response information management
Emergency response information is the all data related to the public
accident emergency response including preplan information, spaceenvironment information, emergency response resource information, on-site

Research on Digitized Emergency Response Preplan for Public Safety in China

47

October 2009, Incheon, Korea

situation information and past cases information. These information are very
important for emergency response, management of these information is thebase function of the preplan.
2) Accident situation analysis and simulation
Accident situation analysis is the analysis by the emergency response
personnel. Such as, analysis of the influence area of the accident, statistics
analysis of the environment in the emergency area, population, facilities,
hazard source and emergency resources, and risk and loss analysis, etc.
These analyses will provide emergency response personnel a comprehensive
and detailed understanding of the process of the accident and emergency
situation. Simulation includes event simulation and emergency response
process simulation. Event simulation refers to the simulation of the event of
the accident and the prediction of the progress tendency, influence area,
damage degree, etc. For example, fire spreading simulation, pollution
simulation, hazardous chemical leak prediction, explosion analysis, social
stability analysis, meteorological disasters analysis, typhoon track forecasts,
landslide and debris flow forecast, a large-scale epidemic spread of thedisease prediction, evacuation simulation. These analyses can help
emergency response personnel understand the trend of accidents, and makethe proper emergency decisions.
3) Emergency response action plan generation and adjustment
Generation and adjustment of emergency response action plan is an
auxiliary decision-making function. The emergency response action plancan be generated by the application of the digitized preplan with model
database, knowledge database, case libraries, on-site situation and otherinformation, and emergency information, accident situation analysis andsimulation results of the current public accident. Emergency response action
plan should not be static, but should change as circumstances change inorder to better adapt to the actual situation. Therefore, digitized preplan
system should adjust the generated action plan according to the accident
information and simulation results.
4) Good human-machine interaction and presentation features
A good human-machine interaction capability for managing
emergency information is necessary (Elizabeth, 2007) . A good presentation
capability can show the accident analysis and simulation results andresponse process visually and directly, which will help emergency response
personnel to better understand the situation more quickly and efficiently andmake decision-making plans.
5) Emergency response effect assessment
Emergency response effect assessment refers to assess the emergency
response steps, methods and results at the different stages of the emergency
response and at the end of the emergency response to confirm if the steps
and methods are correct. After the assessment, the system will be revised
and improved based on the assessment results. After the emergency

48

New Technologies for Urban Safety of Mega Cities in Asia

response, the emergency process will be compiled into a part of the caselibraries.
6) Emergency response exercise
Emergency response exercise is to carry out the accident response
exercise using the digitized preplan system in accordance with the virtual
events and environmental information when no public accidents occur. The
role of the emergency response exercise is to test and improve the digitizedsystem so that emergency response personnel can become familiar with the
emergency response procedures, while revise the imperfect parts of thesystem.
2.3 Structures of digital emergency response preplan
As a software system, the digitized preplan system needs
corresponding software modules.
1) System operating interface
In order to make the digitized preplan system has a good humanmachine interaction and presentation capabilities, the system interface
should be intuitive and clear, easy to use, beautiful and generous.
2) Database system
Database system manages all data information of the digitized preplan
system, including knowledge database, model database and case libraries.
Knowledge database includes related general and professional
knowledge applied in the emergency response decision-making process.
Model database includes all model data for accident analysis and simulation,such as the evolution and impact models, crowd evacuation and early
warning classification model. Case libraries include the information of thepast cases.
3) Analysis and simulation system
Analysis and Simulation system conducts the accident situation
analysis and simulations. Speed and accuracy are necessary. Usually, it isdifficult to satisfy both speed and accuracy. Fast model is not too accurate
and the simulation speed of the relative accurate model is not satisfied.
Therefore, it requires trade-off consideration. Usually, high accuracy modelis used for preplan and a faster model is used for on-site simulation. For
practical applications, a compromise plan will be applied to try to meet therequirements.
4) Decision-making support system
Decision-making support system helps emergency response commandpersonnel to complete the generation and adjustment of the emergency
response plan. The system operates throughout the emergency response
process from the beginning to the end, which is the core of digitized system.
Decision-making support system integrate the preplan information, databasesystems and on-site information to provide emergency response resources

Research on Digitized Emergency Response Preplan for Public Safety in China

49

October 2009, Incheon, Korea

management and ensure the necessary resources through the master of themain rescue teams, emergency response reservation supplies and rescue
equipments, emergency response communication systems, medical
emergency response agencies, and emergency response financial reservation,etc. If necessary, it can rapidly provide new resources arrangement plan andachieve interactive, dynamic decision-making command.
5) Assessment system
Assessment system accomplishes the emergency response effectassessment by automatically recording of the accident response process,determination of the assessment index in accordance with the provisions of
the emergency preplans and the integrate evaluation of timelines andefficiency of various measures in the emergency response and theevaluation of the emergency response ability combined with early warning
system.
6) Geographic information system
Geographic information system is the support system of the digitizedsystem to complete various functions. It can achieve the functions, such as
spatial location, inquiry, spatial analysis. GIS can provide data support andspatial decision support for emergency response decision making with thepowerful spatial inquiry and spatial analysis capabilities.
3. DIGITIZED EMERGENCY PREPLAN FOR FIRE SAFETY OF
BEIJING OLYMPIC VENUES
The emergency response preplan for fire safety focuses on those activities
which are directly related to an evolving firefighting or response of thepotential incident. For the Olympic venue fire safety, it is the mostimportant to direct based on the emergency response plan of the firefighting.
To meet the demand of firefighting in the Olympic projects, Beijing Fire
Bureau joined Tsinghua University and other agencies in researching anddeveloping the digital firefighting project and the synchronized training
system.
The Olympic venue fire safety preplan for emergency response provides aframework to enable the management of fire protection and firefighting aswell as the prevention of and preparation for subsequent events. The mainelements that should be included are: basic information about the venue andimportant units, combustible material and fire load, firefighting force
distribution, put-out and rescue tactics, water supply methods, etc. The
preplan is named as Fire Emergency Response Information System.
3.1 Fire emergency response information system design
The fire emergency response actions include from initial notification
to early coordination efforts to assess and disrupt the incident, topreparatory activation of the response preplan, to deployment of city

50

New Technologies for Urban Safety of Mega Cities in Asia

resources in support of firefighting and rescue operations. Fire brigade,police, public health and medical, emergency management, and otherpersonnel are responsible for Olympic venue fire at the city level (Sun et al,2006).
The fire brigade moves quickly to coordinate multiple department(police, public health and medical, etc.) activities which include thefollowing: information-sharing (Jackson, 2006), integration of the resources,
analysis and forecasting, alert and decision-making (Fredholm, 1997,
Danielsson, 1998), interagency course of action development, operational
coordination, and other assistance. In order to implement the firefighting
and realize the purpose to fire response plan, all of these need acomprehensive information system for fire safety to bring together andmake use of all necessary response resources quickly and effectively.

Beijing Olympic Stadium Digital Fire Response System

Plans
SystemTraining
SystemDecisionmakingSecurity
CommandFigure 2. The fire emergency response information system
After being classified, the elements needed to be considered of the fire
emergency response information system, as shown in Figure 2, include:(1) Basic information of venue and its important parts
Such as venue name, address, unit layout, fire prevention zone,
evacuation route, main combustible material type and quantity, fire hydrant
and locations of firefighting forces, etc.
(2) To design and set fire
Original point of the fire, type of combustive material, fire power
curve, type of the fire, possible serious consequence; temperature andconcentration change of smoke, evacuation route, etc. are necessary.
(3) Task for fire fighting, control, search, rescue, evacuation
Such as arriving time and parking location of fire fighting vehicles,
assigned tasks and resources, attack and back route, real time alarms, newresource requests and resource allocation, co-operation of multiple
departments, etc.
(4) Firefighting tactics
Such as different material, different units, different buildings, different
regions, different stages of the fire, different technical measures, different
games, and different crowd, different water supply methods, etc.
Research on Digitized Emergency Response Preplan for Public Safety in China

51

October 2009, Incheon, Korea(5) The others
Such as personal protective measures, information on casualties andlosses, notes for special type of fires, environment conditions andinformation of adjacent buildings, etc.
The fire emergency response system is designed to improve theresponse operations more scientific, effective, and efficient. It is acentralized solution for firefighting correlation, information sharing,
resources aggregation, fire development analysis, firefighting and rescue,evacuation and investigation of fire events with the networked matrix mode.
Using simulation and GIS technology, the information system
combines hazard layers with city databases, and then applies standardized
loss estimation and risk assessment methodology. The platform environment
allows users to create graphic presentations, helping users visualize andunderstand their fire risks and solutions.
The information system gives decision-makers the tools to makebetter decisions. It establishes a mechanism for sharing the information all
cross city including basic geographical information and public safety
information, enhances the analysis of available options for rescue operation,
optimizes the decision-making process, and can greatly improve the ability
to select the best course of response plan.
3.2 General frame and functional modules of the information system
The general frame of the fire emergency response information system
is shown in Figure 3:
Plan applied system
Basic information module

Plan apply

Fire setting and response module
Plans basePlan production and maintenanceTraining
systemPlan expression

Tools module

Interface platform
GIS platform

3D visual platform

Database system
GIS database

Building structure

Fire simulation model

Firefighting resource

Other
information
systemFigure 3. The general frame of the fire emergency response
information system
The database of information system includes five parts: GIS database,building structure data, fire simulation models data, firefighting resource
data, and plan database. In order to fulfill the fire emergency response plans,

52

New Technologies for Urban Safety of Mega Cities in Asia

it is necessary to obtain the full and accurate geographical information andfire safety related information. The fire emergency response information
system has already included a large amount of relevant basic information,such as topographical data of the city, pipe network data of the urban
lifeline, information of the dangerous source, key place and infrastructure,
rescue force, population distribution and layout of refuge area, etc. The data
involved are extensive and complicated in space distribution to meet anurgent need for fire safety.
Emergency warning
DecisionMaking……
Deciding & commanding
Resource allocation
Firefighting plan……
Response Plan

Water supply plan
Special solution plan

Fire Emergency
Response System

Fire spread simulation
Fire Simulation
Model

……
Smoke and CO simulation
Crowd evacuation simulation
Database of basic information……

Database

Database of geography
Database of firefighting resource

Figure 4. The function flow of the fire emergency response
information system
Figure 4 describes the procedure how to get the executable action plan.
We can obtain venue information from the monitoring system with the aidof GIS system, use the information in the fire response information system
database, then choose the model which accords with present terms from thefire model database, input the data to forecast fire spread and analyze its risk.
The results of calculation of these models can offer scientific basis for thefirefighting and rescuing. Namely, according to the prediction result andfirefighting resource distribution, the response plan is selected from the plan
database, to optimize decision-making, and form series implementing
commands and actions.
Figure 5 and Figure 6 give some examples about the visual interface
in information system. Figure 7 illustrates that the system can provide
valuable decision making support for fire emergency response. Theinterface shows the overall comprehension picture corresponding to thesurround information of a venue fire incident. It displays information about
venue, related buildings, outside hazards, supporting fire station, hospitals
and police stations near to the vicinity of the incident. All on-site and onroad resources are given to plan overall consideration and arrangement

Research on Digitized Emergency Response Preplan for Public Safety in China

53

October 2009, Incheon, Korea

according to the risk assessment. The on-going actions and the next tasks
are adjusted according to response development.

Figure 5. The photo of Fengtai softball venue and the visual interface ininformation system

Figure 6. The fire emergency response preplan layout with RS picture

Figure 7. The firefighting force and resource analysis of
the information system

54

New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSIONS
The research on digitized emergency response preplan for public safety in
China is presented in this paper. Many emergency response preplans are
made to increase the government's capability to protect public safety, deal
with unexpected accidents, minimize the losses of the accidents, maintainsocial stability, and promote the harmonious and sustainable development of
the country. Digitized emergency response preplan is a new type computer
information system based preplan which coupled with past case libraries,
experiences, knowledge database, science model database and on-site
information, etc. It will rapidly provide a direct and efficient action plan
(intelligent plan) and adjust the action plan in real time.
As an example, the digitized emergency preplan for fire safety of Beijing
Olympic venues is shown here. It can give the strong support for
arrangement of action and rescue of extinguishing activity, and provide anadvanced means of strategy, technical and psychologist training for
firefighters, and enhance the comprehensive management of fire emergency
response. The information system has been proven to be not only useful andrapid during firefighting venue fire, but also economical in firefighting
exercise.

REFERENCES
China State Council, 2006. National Emergency Response Preplan.
Danielsson, M., 1998. The cognitive structure of decision making tasks inmajor versus minor emergency responses. In Scott PA, Bridges RS,
Chasterrs J (eds.): Proceedings of the Global Ergonomics. Cape Town,
South Africa, 627-632.
Elizabeth, C., Murray, T., 2007. Human-Computer Interaction: The Humanand Computer as a Team in Emergency Management Information Systems.
Communications of the ACM, 50, 3, 33-38.
Fan, W.C. Su, G.F., 2005. Progress in emergency management research fora Mega-city in China, 4th USMCA International Symposium. Singapore,
31-39.
Fredholm, L., 1997. Decision making patterns in major fire-fighting andrescue operations. In R. Flin, E. Salas, M. Strub & L. Martin (eds.):
Decision Making under Stress. Aldershot: Ashgate, Bookfield USA.
Jackson, B.A., 2006. Information sharing and emergency responder safety
management. Available at: http://www.rand.org/pubs/testimonies/2006/
RAND_CT 258.pdf.
Sun, Z.H., Su, G.F. et al. 2006. Fire hazard analysis and digital fire
emergency response plan, Journal of Basic Science and Engineering 14,
205-211.
Yuan, H.Y., Su, G.F., et al, 2007. Discussion of text preplan, digital preplan
and intelligence preplan in emergency management, China Emergency
Management 4, 4, 20-23.

Research on Digitized Emergency Response Preplan for Public Safety in China

55

BEHAVIOR OF LEVEE MODELSREINFORCED WITH CUTOFF STEELSHEET-PILES DURING EARTHQUAKEMASARU KANEKOThe University of Tokyo, Japanmasaru3@iis.u-tokyo.ac.jp
JUNICHI KOSEKI
Institute of Industrial Science, The University of Tokyo, Japan
koseki@iis.u-tokyo.ac.jp

ABSTRACTThe number of local downpour that causes damage to levee isincreasing recently in Japan. Furthermore, we have tremendous losses dueto the breach of levees all over the world, and this was the exact real case in
the 2005 Hurricane Katrina in USA. Therefore, the role of levee has become
more important than before, in particular with urban areas.
In view of the above, we analyzed results from a series of relevant
shaking table model tests, in which an embankment model resting on aliquefiable sandy soil layer was reinforced with steel sheet-piles. Existenceof sheet-piles affected the response acceleration characteristics andproperties of the excess pore water pressure generation. Bending strains
induced in the cutoff sheet-piles were larger in the deeper part, especially atthe embedded regions. Sheet-piles installed at the foot of the embankment
suffered from larger bending strains than those installed at the shoulder ofthe embankment.

1. INTRODUCTION

Figure 1: Breached levee in USA

Figure 2: Subsided levee in Japan57

October 2009, Incheon, Korea

Fig.1 shows a photograph of breached I-type flood walls in the 2005
Hurricane Katrina, USA (US Army Corps of Engineers, 2006). During the
Hurricane Katrina, collapse of Hurricane Protection System (HPS) triggered
catastrophic damages in southeast Louisiana. Sasanakul et al (2008)
reported that the cause of I-wall’s breaching was composed of two factors;
one is the misinterpretation of geologic conditions and the other is the lackof the penetration depth of the sheet-pile into clay layer.
Fig.2 shows an example of earthquake-induced damage to non-reinforced
levee during the 1995 Hyogoken-Numbu earthquake, Japan. This levee was
located along Yodogawa-river, which separates Osaka and Hyogo
prefectures, and the crest of this levee settled down by 2 or 3 m, due to the
influence of liquefaction in the foundation layer. If a typhoon or heavy
rainfall attacked these areas just after the earthquake, the river water would
overflow easily because of the lack of the levee height, and tremendous
losses would be induced.
These case histories suggest that some of the levees should be reinforced
properly in order to protect our lives and properties from floods. As one of
the methods to reinforce levees, use of steel sheet-piles has been consideredwidely in Japan. For example, the sheet-piles have been used for therevetments along urban rivers. Nowadays, they are also used as thereinforcement for foundation soils against liquefaction.
In view of the above, we set two main targets for our research; the first one
is to examine whether subsidence of a levee could be reduced by means ofreinforcement with steel sheet-piles after liquefaction occurs in foundationsoils, and the second one is to check whether the reinforced levee could
keep its required performance to protect our lives and properties, whenfloods break out. In this paper, regarding the first target, analysis of test
results from a series of relevant shaking table model tests (JASPP 2002) is
conducted, in which reinforcement of the levee resting on a liquefiable
sandy soil layer with steel sheet-piles was made, focusing especially on
response characteristics and bending strains of sheet-piles.

2. MODEL CONTAINER AND TEST CONDITIONS
Elevation (cm)：deformation sensor
Slope:

gravel (20mm thick)

１：１.75：accelerometer

In Fig.9

In Fig.11

84.5

30

54.5

0

19.5

-35

0

-54.5

：pore pressure meter

Rubber

350
195

845

300

Boundary:

P1

P2

Liquefiable layer

No.1
700

Compacted layer
525

300

525

700

2800

Direction of shaking

Figure 3: Model container and the definition of elevation

58

New Technologies for Urban Safety of Mega Cities in Asia

Fig.3 illustrates the configuration of a soil container which measures 2800 mm inlength, 340 mm in width, 845 mm in depth. The model ground and levee weremade of silica sand No.7 (Gs=2.648, D50=0.177 mm, Fc=1.4 %). The model
ground consisted of 2 layers; the lower one named as “compacted layer” having a
relative density Dr of approximately 90%, and the upper one was named as“liquefiable layer” having a Dr value of approximately 40%. During shaking, theground water level was maintained at the surface of the liquefiable layer. The
model levee had a height of 300 mm with the slope of 1.75 horizontal to 1
vertical. Five models with different patterns of sheet-piles installation, named as
No.1 through No.5 as shown in Fig.3 and Fig.4, were prepared. Fig.5 shows two
types of input waves, the one named “a” is the sinusoidal wave (5Hz) withtapered amplitudes, and the other one named “b” is the sinusoidal wave withconstant amplitude (5Hz). Each model was subjected to horizontal excitations byfollowing the 4 steps of excitation events step by step.
Step 1 a-300gal
Step 2 a-500gal
Step 3 b-300gal
Step 4 b-500gal

No.2

No.3

sheet piles( t=２ mm)tie-rodpinned connection to base ofsoil containert = ３mm

No.4

No.5

t = ３mm

t = ３mmt: thickness of sheet-pile model base 

1000
500

a

0
-500

 base 

-1000
5

6

7
8
9 10
時間（sec）
Time (sec)11

Acceleration(gal)
加振加速度（gal）

Acceleration(gal)
加振加速度（gal）

Figure 4: Illustrates of each case base 

1000
500

b

0

 base 

-500
-1000
5

6

7
8
9 10
時間（sec）
Time (sec)11

Figure 5: Input waves

Behavior of Levee Models Reinforced with Cutoff Steel Sheet-Piles During Earthquake

59

October 2009, Incheon, Korea

3. ANALISIS OF TEST RESULTS
3.1 Residual Subsidence

No.1

No.2

No.4

No.3

No.5

24th June 2009

Figure 6: Residual deformation

200
subsidence(mm)
盛Accumulated
土天端累積
沈 下 量 （mm）

No.1
No.2

150

No.3
No.4
No.5

100
50
0
1

2

3

4

Step
Figure 7: Accumulated subsidence
Fig.6 shows the illustrations of the residual deformation observed after
the Step 4 excitation, and Fig.7 shows the accumulated residual subsidence
at the crest of the model. It is noteworthy that, though the lateral flow ofliquefied subsoil was observed in every case, it could be mitigated to someextents due to the installation of sheet-piles except for case No.1. The levee
models with cases No.1 & No.4 remarkably settled down because of no orlack of reinforcement. On the other hand, those of cases No.2 & No.3 did
not subside so largely. These results reveal that sheet-piles that are installed

60

New Technologies for Urban Safety of Mega Cities in Asia

in both shoulders of the levee can exhibit the greatest effects in mitigating
the subsidence of the levee.

Acceleration(gal)
応答加速度（gal）

1000

No.1



500
0



-500

Step 2

-1000
5

6

7

8

9

10 11

Acceleration(gal)
応答加速度（gal）

3.2 Response Acceleration of Levee1000

 5  10   15

500
0

 5

-1000

Step 4
5

6

No.2



500
0



-500

Step 2

-1000
5

6

7

8

9

7

8

9

10 11

時間（sec）
Time
(sec)

10 11

Acceleration(gal)
応答加速度（gal）

応答加速度（gal）
Acceleration(gal)

時間（sec）
Time
(sec)
1000

 10   15

-500

 5  10 

1000
500
0

 15

-500

 5

-1000

Step 4

 10 

 15

6

8

10 11

5

時間（sec）
Time
(sec)

7

9

時間（sec）
Time(sec)

土槽底面からの高さ（cm）
Elevation (cm)

土槽底面からの高さ（cm）
Elevation (cm)Figure 8: Response accelerations at the crest of the levee model
100
75
50
25

Step 1

0
0

0.5

1

1.5

100
75
50
25

Step 2

0

2

0

100
75
50
25

Step 3

0
0

0.5

1

1.5

加速度応答倍率

Amplification

0.5

1

1.5

2

加速度応答倍率
Amplification

2

Elevation (cm)
土槽底面からの高さ（cm）

土槽底面からの高さ（cm）
Elevation (cm)

加速度応答倍率
Amplification
100
75
50
25

Step 4

0
0

0.5

1

1.5

2

加速度応答倍率

Amplification

Figure 9: Amplification factors in each case
Typical time histories of response accelerations at the crest of thelevee model are presented in Fig.8. The maximum amplitudes of responses
acceleration in case No.2 were larger than those in case No.1. The levee
model in case No.1 did not respond considerably due possibly to the effectof base isolation by the liquefiable subsoil under the levee. On the other
hand, the levee model in case No.2 was larger due to the confinement by thepair of sheet-piles and the tie-rod. Fig.9 shows the distribution of theamplification factors of response acceleration measured at the central axis of
the levee model and its underlying liquefiable layer. The elevation is

Behavior of Levee Models Reinforced with Cutoff Steel Sheet-Piles During Earthquake

61

October 2009, Incheon, Korea

measured from the bottom of the compacted layer (Fig.3). The amplification
factors are defined as follows:
Amplification factor = αmax /αbase (Step1, Step2)= αave /αbase (Step3,Step4)
αmax = max(α+, α-)αbase = max(αbase+, αbase-)11αave =  
 i    i  
3  i 5,10,15 2


(1)
(2)
(3)
(4)

α+ & α- are shown in Fig.8, and αbase+ & αbase- in Fig.5. In thispaper, α ave is defined as the average of the amplitudes of response
acceleration in the 5th, 10th, and 15th cycles. No significant difference
between the four cases was seen in Step 1, while clearly different behaviorsof response acceleration were observed in Step 2. In Step 2, the values of
the amplification factors in cases No.2 and No.3 were over 1.0 due possibly
to the effect of confinement by the sheet-piles and the tie-rod, while those inother cases were under 1.0 due to the effect of base isolation as explained
above. In contrast, in Step 3 and Step 4, every case showed a reduced valueof the amplification factor. These results indicate that the influence ofliquefaction appeared in every case, though the extents of liquefaction weredifferent among the different cases.

No.1

500
0
-500
-1000
5

6

7
8 9 10 11
時間（sec）
Time
(sec)

80

P.W.P
(gf/cm2)
過剰間隙水圧（gf/cm2）

1000

500
0
-500
-1000

5

6

7 8 9 10 11
時間（sec）
Time
(sec)

50

P1

20

5

6

7

8

9

10

11

時間（sec）
Time
(sec)

No.2

1000

No.1 水平P1
No.1 下方
P2

P2

-10

80

過剰間隙水圧（gf/cm2）
P.W.P(gf/cm2)応答加速度（gal）
Acceleration(gal)

応答加速度（gal）
Acceleration(gal)

3.3 Pore Water Pressure and Response Acceleration of Liquefiable
Layer

P1
No.2 水平No.2 下方
P2

P2
50

P1

20

-10
5

6

7

8

9

10

11

時間（sec）
Time(sec)

Figure 10: Pore water pressures and response accelerations
In order to investigate more in detail, the difference in the amplification
factors between cases No.1 and No.2 in Step 2, the recorded time histories of
response acceleration of the liquefiable layer under the levee model and excess
pore water pressures measured at P1 and P2 (see Fig.3) are shown in Fig.10. In
terms of the response accelerations, the underlying liquefiable layer showed a62

New Technologies for Urban Safety of Mega Cities in Asia

behavior that was similar to that of the levee itself, as stated in 3.2. The excess
pore water pressures, measured at P1 were almost the same behaviors in bothcases. However, the excess pore water pressure, measured at P2 below thelevee was higher and more rapidly increased after 7sec in case No.1 than incase No.2. Such rapid increase of excess pore water pressure in case No.1 leadto the reduction of effective stress in the liquefiable layer below the levee, andthus affected the response accelerations as well.
3.4 Residual Bending Strain of Sheet-piles
20

Elevation(cm)
深さ（cm）

-20

-20

No.2
-400

-200

0

200

400

600

-60
-600

Elevation(cm)
深さ（cm）

Elevation(cm)
深さ（cm）

020

step1 終了時
step2 終了時
step3 終了時
step4 終了時

-20

-60
-600

No.3
-400

-200

0

200

400

残留曲げひずみ（μ）
Residualstrain (μ)

20

step1 終了時
step2 終了時
step3 終了時
step4 終了時

0

-400

-200

0

200

残留曲げひずみ（μ）
Residualstrain (μ)

400

600

－＋

No.3
-400

-200

0

200

0

200

残留曲げひずみ（μ）
Residualstrain (μ)

400

600

step1 終了時
step2 終了時
step3 終了時
step4 終了時

0

-20

-40

No.4

-60
-600

600

-20

-40

Definition-40

残留曲げひずみ（μ）
Residualstrain (μ)
20

step1 終了時
step2 終了時
step3 終了時
step4 終了時

0

-20

-40

-40
-60
-600

0

Elevation(cm)
深さ（cm）

Elevation(cm)
深さ（cm）

0

step2 終了時
step3 終了時
step4 終了時

20

step1 終了時
step2 終了時
step3 終了時
step4 終了時

step1 終了時

Elevation(cm)
深さ（cm）

20

-40

-60
-600

No.4
-400

-200

0

200

400

残留曲げひずみ（μ）
Residualstrain (μ)

600

-60
-600

No.5
-400

-200

残留曲げひずみ（μ）
Residualstrain (μ)

400

600

Figure 11: Distribution of residual strain of sheet-piles
Fig.11 presents the distribution of residual bending strain of sheet-pileobtained after each shaking step. The vertical axis shows the elevation which ismeasured from the surface of the liquefiable layer (Fig.3), and the direction of
positive bending strain is defined as shown in Fig.11. The strain was defined to
be zero immediately before applying the step 1 shaking. In all cases on thewhole, positive strains appeared from the top of levee to the middle ofliquefiable layer, and negative strains appeared at the deeper positions. They are
influenced by increased earth pressure acting from the levee and the liquefied
subsoil, and the tensile load mobilized in the tie-rod. In cases No.3 and No.4
which have two kinds of sheet-piles, one installed at the shoulder of the levee
model and the other at its toe, the negative bending strains after shaking
become maximum at the lower part of the sheet-pile at the toe.
3.5 Maximum Bending Strain during Shaking

曲げひずみ（μ）*
Bending
strain (μ)＊

1000

正側
＋ 負側
－
No.2
No.3
No.4
No.5

750

＊Strains before Step1 zeroed

500

250

0
1

2

Step

3

4

Figure 12: Maximum bending strains during shaking

Behavior of Levee Models Reinforced with Cutoff Steel Sheet-Piles During Earthquake

63

October 2009, Incheon, Korea

Fig.12 shows the maximum values of both positive and negative
bending strains of sheet-piles during each shaking step. As a whole,negative strains were larger than positive ones except for Step 4 in caseNo.2, and this tendency was more significantly observed in cases No.3 &No.5, as compared to the other cases.

No.2

No.3

：maximum ＋：maximum － +1,+2

+1
+2,+4

+3

-1

+4

-3,-4

-1,-2,-3,-4
+3

-2

No.4
+2

No.5

+3
-4

+1,+2

-1

+3,+4

+1
+4

-1,-2,-3,-4-2,-3

Figure 13: Positions of maximum bending strain
The positions where the maximum bending strain was observed areillustrated in Fig.13 (the numbers in each box indicates the step number).
Almost all the maximum negative bending strains in cases No.3 & No.5
were recorded at the lower part, i.e., at the boundary between the liquefiable
and compacted layers, of the toe sheet-pile that was not connected by thetie-rod. Generally, the maximum bending strains during shaking wererecorded at nearly the same position as the residual bending strain (Fig.11).

4. CONCLUSIONSIn this paper, analysis of results from a series of relevant shaking tablemodel tests on levees reinforced with cutoff steel sheet-piles is made. Test
results revealed that sheet-piles contributed to reduce the subsidence of thecrest of levee, while the extent of the mitigative effect depended on thelocations of their installation. Moreover, sheet-piles affected the response
accelerations and the excess pore water pressures, and they were closely
related with each other. As for bending strains of sheet-piles, they werelarger in the deeper part, especially at the boundary between liquefiable andcompacted layers, and those of the sheet-piles at the toe of the levee model
tended to be larger than those at its shoulder, when two pairs of cutoff sheetpiles were installed.

64

New Technologies for Urban Safety of Mega Cities in Asia

REFERENCES
Japan Association for Steel Pipe Piles (2002) “Technical report on levees
reinforced with steel sheet-piles” 33p. (in Japanese)
Sasanakul , I. et al. (2008) “New Orleans System Performance during
Hurricane Katrina: 17th Street Canal and Orleans Canal North”. Journalof Geotechnical and Geoenvironmental Eng., ASCE, 657-667.
US Army Corps of Engineers (2006) “Performance Evaluation of the New
Orleans and Southeast Louisiana Hurricane Protection System, Draft Final
Report of the Interagency Performance Evaluation Task Force”, V-9.

Behavior of Levee Models Reinforced with Cutoff Steel Sheet-Piles During Earthquake

65

PERSPECTIVES ON SUSTAINABLE
PRACTICES AND MATERIALS IN
THE JAPANESE CONCRETE INDUSTRYMICHAEL HENRY
Department of Civil Engineering, The University of Tokyomwhenry@iis.u-tokyo.ac.jp
YOSHITAKA KATO
ICUS, Institute of Industrial Science, The University of Tokyo
katoyosh@iis.u-tokyo.ac.jp

ABSTRACTOne of the difficulties in adopting sustainable practices is the wide
variety of perspectives on what exactly constitutes sustainability. For theconcrete industry, people have focused primarily on the environmental
aspect of concrete, which typically includes CO2 emissions, resource
consumption, and waste generation. However, the concrete industry itself iscomposed of a large collection of separate social groups, each of which has
their own perspective and goals regarding the usage of concrete and how
sustainability should be achieved. In order to take a step forward towards
resolving a unified approach to sustainable practice in the concrete industry,
it is necessary to understand how these social groups view concrete as atechnology – looking specifically at their relationship to concrete as well as
their knowledge level of sustainability. By evaluating these perspectives, apicture of contrasting problems and solutions can be formed, which willthen allow for progress towards a common goal of sustainable practice bynegotiating the differences between these social groups.

1. INTRODUCTION
The increasing frequency of environmental disasters, such as hurricanes andfloods, has emphasized the importance of considering global climate change
as a danger to public safety. Climate change has been attributed to rapid
growth, urbanization, and industrialization over the past hundred years and,if such unsustainable development continues and deterioration of the global
climate goes unchecked, may lead to more disasters due to rising sea levels
and changes in wind and temperature patterns (IPCC, 2007).
In order to prevent or mitigate these future disasters, modern
societies are attempting to adopt sustainable practices by considering theeffects of their actions on the development of future societies. However,even though sustainable development was proposed by the United Nationsin 1987, the term was defined in at least 57 different ways from 1979 to
1997 (Murcott, 1997), demonstrating that there still remains much debate67October 2009, Incheon, Korea

regarding what constitutes sustainability. One modern means of visualizing
sustainability is given in Figure 1, where it is shown as the integration of thethree “pillars”: the environment, society, and the economy. This image
captures the idea that the three pillars are not separate but, rather, there
exists a co-dependency between them; for example, the well-being ofsociety depends on the well-being of the environment.

Economic
SocialEnvironmental

Figure 1 Visualization of sustainability (Cornell, 2009)
The concrete industry contributes both positively and negatively to
all three of the areas shown in Figure 1. The concrete industry is a massive
employer world-wide, and concrete material is a fundamental component of
the infrastructure necessary to support human society. However, concretealso carries with it a significant environmental impact, from emissions due
to manufacturing and transport to resource consumption and land use formaterial production. Furthermore, the production of concrete infrastructure
is not a simple process, but involves the labor and cooperation from manydifferent stakeholder groups, such as general contractors, ready-mix plants,
cement manufacturers, researchers, government agencies, and so forth. Eachof these groups has a unique role, and thus different perspectives and goals.
Furthermore, different stakeholders are going to be affected by sustainable
practice in different ways, and they may have to compromise theirindividual goals in order to meet social or environmental requirements.
It is necessary to consider these different perspectives in order todevelop a unified approach to sustainable practice in the concrete industry.
This paper takes the first step in this process by dividing the concrete
industry into different social groups and evaluating their perspectives on
topics relating to concrete, sustainability, and sustainable practice andmaterials in the concrete industry.

2. METHODOLOGY
2.1 Selected social groups
For this study, the Japanese concrete industry was selected due to theauthors’ access to experts through domestic industry contacts. The industry
itself was divided into four categories: academic, government, contractor,
and manufacturer. These categories were selected based upon the structureof the Japanese industry and consideration of the social groups relevant to68

New Technologies for Urban Safety of Mega Cities in Asia

concrete construction, as described in Figure 2. For civil structures, thegovernment is typically the owner. These groups may also be composed ofsub-groups; the government has research institutes as well as construction
bureaus, contractors have internal divisions and research groups, andmanufacturers include cement producers, aggregate quarries, ready-mix
concrete plants, chemical admixture companies, and so forth.
Government
Research

Concrete structure

Contractor

Academic

Concrete materials

Manufacturer

Figure 2 Conceptual structure of concrete industry (civil structures)
2.2 Semi-structured interviews
The social groups’ perspectives were evaluated using semi-structured
interviews. Semi-structured interviews fall between structured andunstructured interviews, as shown in Figure 3, where the dimensions aredegree of structure and depth. Structured interviews are rigid andstandardized, with precoded categories for responses, and do not investigate
in great depth; unstructured interviews are flexible, following a general setof questions which guide the overall direction of the interview but allow forareas of interest to be investigated in further detail (Punch, 2005).
Structured
interviews

Semi‐structured
interviews

Unstructured
interviews

Standardized interviews
Survey interviews
Clinical history taking

In‐depth interviews
Survey interviews
Group interviews

In‐depth interviews
Clinical interviews
Group interviews
Oral/life history interviews

Figure 3 Continuum model for interviews (Minichiello et al., 1990)
After contact was made with the interview subjects, they were
provided with an interview summary which contained an overview of the
primary questions to be asked. The interview was then conducted following
the primary questions, but deviating as necessary to provide clarification on
topics of interest. In some cases, the interviewee provided answers to thesummary before the interview, in which case the interview was conducted toclarify or expand upon the interviewee’s response in greater detail. Theinterviews were generally conducted in English, but when Japanese wasused interview results were translated to English before analysis.
2.3 Research hypotheses & interview topics

Perspectives on sustainable practices and materials in the Japanese concrete industry

69

October 2009, Incheon, Korea

This research was conducted in order to understand the perspectives
held by different social groups within the concrete industry on the adoptionof sustainable practice. Therefore, two main hypotheses were proposed:(1) The social group’s perspective on sustainable practice is affected bytheir relationship with concrete.
(2) The social group’s perspective on sustainable practice is affected bytheir concept or definition of sustainability.
Based upon these hypotheses, a general outline of the interview topics isgiven in Figure 4. Sustainable practice in the concrete industry was broken
into three different categories based on the authors’ research interests.

Social group
Relationshipto concrete

Knowledge ofsustainability

Sustainableconcrete practices
Evaluation ofsustainability

Sustainable
materials

Barriers tosustainability

Figure 4 Outline of interview topics
2.4 Coding
Interview results were organized and analyzed by coding. Codes aretags or labels used to give meaning and are attached to data, such as words,
sentences, or paragraphs, in order to facilitate retrieval and organization ofdata for clustering and drawing conclusions (Miles & Huberman, 1994).
After conducting the interviews an initial list of codes was constructed to
begin analysis and refine the interviewing process for future interviews.
Some examples of codes and their definitions are given in Table 1. These
codes describe the social groups’ perspectives by identifying goals,
relationships, indicators, definitions, conflicts, problems, and actions.

Code
GOAL
REL
IND
DEF
CONF
PROB
ACT

70

Table 1 Examples of codes and definitions
Definition
The social group’s goals or targets
Relationship between the social group and another social group
Indicators used for evaluating concrete, sustainability, etc.
The social group’s definition of a term or concept
Conflict between the social group and another social group
Problem as viewed by the social group
Action the social group should take or believes should be taken

New Technologies for Urban Safety of Mega Cities in Asia

3. INTERVIEW RESULTS & DISCUSSION
3.1 Distribution and description of interviewees
The distribution of interviewees is shown in Figure 5 and described in Table
2. Six people were interviewed: five of them are involved in research and/or
technology development; four of them have worked in an academic setting
and have doctoral degrees; three of them are directors or managers; half of
the interviewees belong to material manufacturing companies; one is a CEO
and one is a professor.
1

1

Government
Contractor

1

Manufacturer
Academic
3

Figure 5 Distribution of interviewees

Interviewee
Government
Contractor
Manufacturer
Academic

Table 2 Interviewee descriptions
Description
Director, independent government research center
Chief researcher, general contractor
Technology and Development director, cement company
Development center manager, chemical admixture company
CEO, concrete ready-mix plant and aggregate quarry
University professor

3.2 Relationship to concrete
The conceptual structure of the concrete industry shown in Figure 2
illustrates that each social group interacts with concrete differently. The
relationship of these groups to concrete is also dependent on the relationshipbetween social groups, depending on their role in the construction process.
Within the manufacturer group, the cement and chemical admixture
companies are providing a product to the ready-mix plant which produces
the actual concrete material for construction. Since the ready-mix plant is
the customer of the cement and chemical admixture companies, thesecompanies develop and evaluate their products considering the criteria
which the ready-mix plant uses to evaluate its products (Table 3). Concrete
is typically specified by compressive strength, slump, and aggregate
gradation, so the ready-mix plant evaluates their product based on thesecriteria. However, since anyone can produce concrete which meets these
specifications, concrete quality becomes an important criterion for customer
satisfaction. Although ready-mix plants do not have the means forevaluating durability, it may be specified by the owner, so cement andadmixture companies need to consider this performance as well.

Perspectives on sustainable practices and materials in the Japanese concrete industry

71

October 2009, Incheon, Korea

Table 3 Evaluation criteria for concrete materials
Interviewee Indicators
Government Hardened (strength, durability), cost
Contractor
Cost, quality
CementHardened (strength, durability), cost, quality
company
Admixture
Fresh (viscosity, fluidity, pumpability, slump retention),company
hardened (strength, durability)
Ready-mix
Fresh (slump, air content), hardened (strength)
Academic
All criteria
The contractor’s role is to construct infrastructure using the concrete
produced by the ready-mix plant. Construction is performed according tocontract between the contractor and the owner, so the contractors wants toutilize concrete materials with low cost and high quality to meet budget
requirements and ensure structural performance. The owner, in turn, isfocused on the cost and performance (strength and, in some cases,
durability). The academic institution supports all levels of this process byproviding research for solving problems found in practice or developing
new technologies, techniques, or standards from basic on-going research.
However, researchers may not consider cost even though it is important
throughout the construction process and used by the other social groups.
3.3 Knowledge of sustainability
Although the relationship of a given social group to concrete may be
the same when considering different individuals or organizations within thesame social group, knowledge of sustainability is largely dependent on
individuals, so that even within the same organization or social group there
may be widely varying ideas regarding sustainability. For this research work
it is assumed that, since the selected interviewees occupy positions whereby
their ideas affect the development or direction of their organization, theirindividual ideas can be representative of their organization.
The visualization of sustainability shown in Figure 1 emphasizes thedependency between the environment, society, and the economy. Thisdependency is also shown in the perspectives on sustainability held by theinterviewees, which are summarized in Table 4. The common theme
between the interviewees is the importance of reducing CO2 and CO2 as anindicator for sustainability. The environment is frequently referred to in bothconcept and indicators, including CO2, resource consumption, waste usage,
recycling, and others. Societal issues are also referenced, such as humanactivity, safety, community, health, and social merit. Economic issues are
mentioned the least, with economic merit and cost/benefit suggested as twomeans of evaluation. It can be clearly seen that most of the definitions andindicators are focused on the environmental impact, followed by social andeconomic issues, which reinforces the hierarchy in Figure 1.

72

New Technologies for Urban Safety of Mega Cities in Asia

Interviewee
Government

Contractor
Cementcompany
Admixturecompany
Ready-mix

Academic

Table 4 Perspectives on sustainability
Concept
Indicators
Maintain current level of life
while developing humanEnvironmental impact, CO2,
activities, but environment
natural resource consumption
affects all activities
What everyone can use or do
Safetysafely from now
CO2, recycling, land use
Maintaining and improving
management, resource
built and natural environment
consumption, waste materials
Environmental impact, CO2,Society will define based onclean air and water,
environmental issues andcontamination and pollution,
economic meritsocial and economic merit
Reduction of CO2
CO2
Resources, air, CO2, water,soil, noise, waste, economic
effect (cost/benefit),
Reduction of CO2
community, land systems,
population statistics, safety,
health, comfort, biodiversity

3.4 Sustainable concrete practice
The final part of the interview focused on the interviewees’
perspectives on sustainable practice in the concrete industry, considering inparticular how to evaluate sustainability, sustainable materials, and barriers
to sustainable practices. The proposed indicators or methods for evaluating
sustainable concrete practice are given in Table 5. From these results it canbe seen that durability, LCC, and CO2 are the most common indicators
proposed. Durability and LCC are the main engineering-based indicators,
whereas several different sustainability-based indicators were alsomentioned, including recyclability, environmental preservation, and social
benefit. However, most of the interviewees agree that considering cost andCO2 emissions over the life cycle are the most important means forevaluating sustainability.
Table 5 Sustainable concrete practice indicators
Interviewee Indicators
LCC, life cycle CO2, durability, recyclability, use of waste
Governmentand recycled materials, preservation of natural environment
Contractor
LCC, durability, recyclability, use of inorganic materials
Cement
LCC, life cycle CO2, environmental impact, durability
company
Admixture
LCC, life cycle CO2, environmental impact, durability, social
company
benefit
Ready-mix
Durability, workability, reliability, constructability, LCA
Academic
CO2, other criteria dependent on project

Perspectives on sustainable practices and materials in the Japanese concrete industry73

October 2009, Incheon, Korea

Given these indicators, sustainable concrete materials should bedesigned considering durability of the material in both the fresh andhardened states, and selection of materials should be conducted based uponevaluation of LCC and life cycle CO2. Waste and recycled materials should
also be used if possible, but it is important to maintain durability and quality
since these materials are of inferior quality. Since cement is the primarycontributor of CO2, the use of admixtures or alternative cementitious
materials is necessary to reduce the volume of cement as much as possible.
The results in Table 5 showed a general consensus among the socialgroups regarding what indicators should be used for evaluating sustainable
practice, and criteria for sustainable materials could be proposed based uponthis consensus. However, there exist many barriers to the adoption of thoseindicators and the practical application of such materials, as summarized inTable 6. Among these, the problem of establishing an evaluation system isthe most prominent. To ensure transparency, official inventory data and astandardized code are necessary. Furthermore, current evaluation systems
focus on initial cost, so environmental impact evaluation needs to be
integrated with the current system, as well as means for evaluating
additional value other than reduced environmental impact. Finally, there areproblems of perception. Since recycled materials are inferior in quality,
concrete with recycled materials is avoided because people believe that
quality cannot be assured. However, the greater problem is the perceptionthat concrete as a construction material is not environmentally friendly.
Table 6 Barriers to sustainable concrete practice
Barriers
Lack of inventory data, lack of standardized code,
government focus on cost-benefit ratio which doesn’t include
Government
environmental cost, CO2 specification relative not absolute,
reluctance to use new or unfamiliar materials
Focus on initial cost, government doesn’t consider long-term
Contractor
usage of infrastructure
Lack of standardized code, gap between specifications andactual quality, ready-mix cannot evaluate durability, lack of
Cementvertical integration, over-design of structures, gap between
companyhigh compressive strength and high durability, perception of
concrete as not environmentally friendly
Loose environmental codes, balance between company andAdmixturesocial benefit, perception of concrete as not environmentallycompany
friendly
Lack of inventory data, lack of standardized code,
Ready-mixtransparency in calculating CO2, balance between different
evaluation criteria, perception of recycled materials
Lack of standardized code, transparency in calculating CO2,
focus on initial cost, can’t evaluate additional value, balance
Academic
between different evaluation criteria, sustainability
knowledge gap among people
Interviewee

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New Technologies for Urban Safety of Mega Cities in Asia

3.5 Relating concrete use and sustainability to sustainable practiceIn Section 2.3 two hypotheses were proposed: that sustainable
practice was affected by the relationship to concrete, and that sustainable
practice was affected by the knowledge of sustainability. From the resultspresented in Section 3.2, it was found that the social groups’ relationshipwith concrete was tied to the interaction between the social groups and theirrole in the concrete production and construction process. However, althoughdurability was specified as an evaluation criterion by several groups,
demand for durability derives from the owner, who typically only specifies
strength. The perspectives on sustainability found in Section 3.3 followed
the general hierarchy presented in Figure 1 and most of the emphasis wasplaced on environmental indicators – primarily CO2 – although social andeconomic merit were also mentioned. The results of Section 3.4 showed that
evaluation of sustainable practices and materials should be conducted using
durability, LCC, and life cycle CO2. The selection of CO2 as a sustainability
indicator for the concrete industry can be derived directly from the emphasis
placed on CO2 as a general environmental indicator; however, durability and
LCC are not currently used to evaluate materials in practice (althoughdurability may be specified in some cases). This follows directly from thebarriers identified in Table 6, which showed that there is a lack ofstandardized code for evaluating LCC, emphasis is placed on initial costrather than LCC, lack of consideration for long-term usage in somegovernment officials, and lack of method for ready-mix plants to evaluate
durability. Furthermore, although there is consensus on the importance oflife cycle CO2 as an indicator, a standardized method for evaluation andensuring transparency has not yet been established. Figure 6 shows therelationship between these issues.
Evaluation criteria for
concrete materials

Durability, LCC

Standardized code, consider life cycle,
durability evaluation, industry structure

Sustainableconcrete practices
Life cycle CO2
Sustainability
indicators

Standardized code, inventory data,transparency, consider life cycle

Figure 6 Deriving sustainable concrete practices from relation to concreteand sustainable knowledge
Finally, the importance of each social group’s role in the production
and construction process (the industry structure) is a key point fordeveloping sustainable practice. The additional value of utilizing sustainable
materials needs to be evaluated at each stage of the production andconstruction process, so the role each group plays needs to be consideredwhen developing codes and boundary conditions for the evaluation of life
cycle costs and CO2 emissions.

Perspectives on sustainable practices and materials in the Japanese concrete industry

75

October 2009, Incheon, Korea

4. CONCLUSION
In this paper, the perspectives on concrete, sustainability, and sustainableconcrete practice were presented for different social groups in the Japanese
concrete industry. It was found that the relationship each group has withconcrete is dependent upon their relationship with other social groups due tothe structure of the Japanese industry, and that different evaluation criteria
are applied at different stages of the construction process. The ultimate
product of the manufacturing stage is fresh concrete from the ready-mix
plant, so cement and admixture companies focus on assuring the quality andimproving the performance of criteria which the ready-mix plant has tosatisfy – usually slump and compressive strength. However, the ready-mix
plant is more concerned with providing quality concrete to satisfy therequirements of the contractor, whose contract with the owner requires thatthe contractor provide a certain level of quality at a specified price. Even
though each social group relates differently to concrete, the interviewees
generally gave similar responses when asked to define and evaluatesustainability. Environmental impact, such as CO2, received the greatestemphasis, with less emphasis on social and economic concerns. This result
reinforces the hierarchy shown in the visualization of sustainability in
Figure 1. When considering the development of sustainable practice for theconcrete industry, boundaries need to be overcome in order to implement
the practices which are considered necessary. The current specification
process for concrete emphasizes strength and initial cost; however,
evaluation methods and standardized codes should be developed which canprovide the means for considering durability and life cycle cost in theevaluation process. CO2 is clearly a vital indicator for understanding theenvironmental impact, but standardized evaluation methods, inventory data,
and transparency need to be established and considered along withdurability and life cycle cost. Finally, boundary conditions for theseevaluations need to be set considering the industry structure.

REFERENCES
Cornell, 2009. Cornell University Sustainable Campus (online). Available
from: http://sustainablecampus.cornell.edu/csi.cfm (28 August 2009)
IPCC, 2007. Climate Change 2007: Synthesis Report. Intergovernmental
Panel for Climate Change, Geneva.
Miles, M.B and Huberman, A.M., 1994. Qualitative Data Analysis. SAGE
Publications, London.
Minichiello, V., Aroni, R., Timewell, E., Alexander, L., 1990. In-DepthInterviewing: Researching people. Longman Cheshire, Melbourne.
Murcott, S., 1997. What is sustainability? AAAS Annual Conference/IIASA
Sustainability Indicators Symposium, Seattle, USA.
Punch, K.F., 2005. Introduction to Social Research. SAGE Publications,London.

76

New Technologies for Urban Safety of Mega Cities in Asia

LANDSLIDE MOVEMENT AND
DEFORMATION FOR DIFFERENT LENGTH
AND WIDTH OF LANDSLIDE MASSMUNEYOSHI NUMADA
International Center for Urban Safety Engineering
Institute of Industrial Science, University of Tokyo, Japannuma@iis.u-tokyo.ac.jp
Kazuo KONAGAI
Institute of Industrial Science, University of Tokyo, Japan
konagai@iis.u-tokyo.ac.jp
ABSTRACT
It is important to forecast the run out-distance of landslides mass to
reduce the landslide disaster. This research aims to analyze the key
parameter that control the run out-distance of landslides mass. The
numerical analysis is an effective approach to analyze the dynamic
mechanism of the landslide. For numerical analysis, Material Point Method(MPM) is used in this research.
The condition requested from the numerical analysis includes two
following elements: 1. Large deformation of soil; and 2. Input parameterscomposed of information which can be measured. Input parameters appliedin MPM model are slope form (geographical features and slide surface),
physical properties of deformation of sliding mass (geological features) andphysical properties of sliding surface
The parameters that control the run out-distance of landslides mass
are geometry, physical property and frictional coefficients to observe thecontribution to run out-distance. For different lengths of the landslide mass
( L ), the mass movement is examined in the time-marching calculation ofMPM. Lengths of the landslide mass segments L1 and L 2 on the level andinclined sliding surfaces are obtained respectively at every time step. Also
width of a landslide mass can be analyzed. As the width increases, the curve
converges on the plane-strain solution, and it is rather closer to plane-stresssolution for thinner soil cases. The ultimate load capacity F would be morecrucial in determining its distal reach.
This research introduced some results for extracting importantpieces of information for landslide risk assessment from numerical modeland real landslide masses. For coherent mass movements, numericalsimulation of landslide mass movements using MPM did hint an idea for
extracting parameters from real landslide masses. This knowledge will
provide a good perspective for landslide risk assessments.

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October 2009, Incheon, Korea

1. INTRODUCTION
Landslides can range in size from small movements of loose debris
to massive collapses of entire summits. For short to medium-length slopes,
installing preventive drainage works, anchoring and/or reinforcing slopes
will be effective for assessing and mitigating landslide hazards. However for
extremely large slope failures, it is very difficult to mitigate and thus theimportance of run out analysis emerges. Many landslides with limited
internal deformation will move as coherent masses on thin mobile basal
layers. However, others will become flow-like in character after runningsome long distances, though exhibiting some solid features at their earlystages of failure. It is important to forecast the run out distance of landslides
mass to reduce the landslide disaster.
This research is aim to analyze the key parameter that control the runout distance of landslides mass. The numerical analysis is an effective
approach to analyze the dynamic mechanism of the landslide. For numericalanalysis, Material Point Method (MPM) is used in this research.

2. NUMERICAL PROCEDURES IN MPM ANALYSIS
2.1

Overview of MPM

The MPM is categorized as one of the mesh-less methods formulated
in an arbitrary Lagrangian-Eulerian description of motion. In MPM, a bodyis to be analyzed as a cluster of material points. Material Point has
information of physical properties on a peculiar position and the stress, etc.
The material points, which carry all Lagrangian parameters, can move freely
across cell boundaries of a stationary Eulerian lattice, and the information is
distributed to each node of belonging cells. This mesh is called ascomputational mesh, should cover the virtual position of the analyzed body.
The computational mesh can remain constant for the entire computation,
thus the main disadvantage of the conventional finite element method
related to the problem of mesh distortions is eliminated for large
deformation of soils (Figure 1).

node

Eularian Latticematerial point: mp

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New Technologies for Urban Safety of Mega Cities in Asia

2.2

Figure 1: Eularian lattice and material points
Modeling of landslide mass

All Lagrangian parameters for the entire landslide mass are hardly
obtained. For example, it is often that the plants growing on a landslide
mass shoot their roots all through the soil mass. In such a way that overallcharacteristics of the soil mass is largely different from those obtained
through test of soil samples taken point-wise from the landslide mass.
The condition requested for the numerical analysis includes two
following elements: 1. Large deformation of soil; and 2. Input parameterscomposed of information which can be measured. Input parameters appliedin MPM model are slope form (geographical features and slide surface),
physical properties of deformation of sliding mass (geological features) andphysical properties of sliding surface.
A lot of parameters that constitute physical properties of landslide
are taken into real landslide phenomenon, but the pseudo-three dimensionalmodel can reduce the number of complex parameters as much as possible.
The landslide mass is considered to be equivalent fluid in this model andmodeling it as assemble of soil columns. In such a model, complex landslide
model can be expressed by the interactive force between soil columns, basal
force and reducing necessary parameters. Therefore, there is an advantagethat the computational complexity can be decreased at the computing leadtime (Figure 2).
■ 3D■ not base
Neglect toStress, velocityZyx■ Pseudo 3D

σ iz = 0■ baseVertical stress:
Soil column

Shear stress:

σ zz bed
σ zx bed , σ zy bed

Figure 2: Pseudo three dimensional model of landslide mass

3. NUMERICAL SIMULATION FOR DIFFERENT LENGTH AND
WIDTH OF LANDSLIDE MASS
3.1

Modeling of landslide mass

For landslide mass is modeled in MPM, width of the landslide W and
depth H are made constant, the landslide length is set different six patternfrom 20 to 100m length (Figure 3). The initial thickness H of the landslide

Landslide movement and deformation for different length and width of landslide mass79

October 2009, Incheon, Korea

mass is set to 1m. A rectangular-planner soil mass of 1m thick is assumed tobe resting on a flat slope dipping to a level ground, which spreads in
immediately front of the toe of the landslide mass. The slope angle of MPM
model is set uniformly to 20 degrees. The coefficient of friction is set
separately on the slope side and flat surface side, and the coefficient of flat
surface side μ1 and slope side μ 2 are 0.8 and 0.2 respectively (Table 1).
The Young’s modulus of the landslide mass E is taken as 2×106 Pa,
poisson’s ratio is 0.3, internal frictional angle φ is set to 30 degrees,
cohesion c is derived from Rankin’s earth pressure model to stand upright
1m height in the gravity. The constitutive law of landslide mass is used
Drager-Prager model. The initial material point for one cell arranges to be
2×2 for 0.2m×0.2m size cell.
plane

foot

HeightContour Line※slope angle = 20deg

Foot of slope

A

A

W=2m

L=80m
cross
H=1m

20deg

Figure 3: MPM model for different length of landslide mass(upper: plane view, lower: cross)80

New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Parameter of landslide mass and MPM setting
Topic
Comment
Sliding surface dip
20 degμ1 (flat surface)0.8
μ 2 (slope surface)0.2
φ (soil mass)
30 degYoung’s modulus
2×106 Pa
Possson’s ratio
0.3
Density
1600 kg/m3
Cell size
0.2m × 0.2m
Initial arrangement of
2×2
particles in a cellTime increment
5 × 10-4

3.2

Numerical result of different length of landslide mass

For different lengths of the landslide mass L , the mass movement is
examined in the time-marching calculation of MPM (Figure 4). The run outdistance L1 is defined as the distance from boundary of slope-flat surface
zone to head of the landslide mass, and L 2 is the distance of the landslide
mass that remains of a slope side (length of the remaining on the slope).
These are obtained at every time step. The average stress σ a is the averagevalue of the stress that acts upon the boundary on a slope and flat side. The
average stress σ a is calculated the average value of the stress of node on theboundary between a slope and a flat surface side. Initially landslide mass
keeps L1 + L 2 to be completely identical to the entire length of the landslide
mass L . to be exact, the entire length is kept unchanged (Figure 5).
However, as the landslide mass runs further forward over the levelground (deposition zone), its movement slows down due to larger frictionalcoefficient and with no driving force induced on the level ground.
Eventually the following segment of the landslide mass pushes the soil frombehind, and immediately after the ultimate load capacity F , the average
stress σ a reaches peak strength σ p , that the limit landslide mass can sustain
is reached and L1 + L 2 value is starts shrinking ( L1 + L 2 < L ).
For long landslide masses, L1 converges on a constant value,
ultimate L1y , suggesting that the entire length of the landslide mass has little
or nothing to do with the ultimate load capacity. In the other word, there is
the upper bound of distal reach of the landslide mass. It will be also a matterof course that L 2 can converge likewise on a particular value, ultimate L2y ,with the presence of the ultimate load F .

Landslide movement and deformation for different length and width of landslide mass81

October 2009, Incheon, Korea

Flat

Slope (20 deg)

Figure 4: Plane view of height of landslide mass for different length(Time = 15s)

82

New Technologies for Urban Safety of Mega Cities in Asia

L

L1y

Cross
foot

σa σa
L1[m]

L2[m]

Figure 5:Relationship between L1 and L2 for different
length of landslide mass
3.3

Numerical result of different width of landslide mass

Width of a landslide mass can also affect F and therefore L1 y andL 2 y , as the width increases, the curve converges on the plane-stress solution
for thinner soil cases (Figure 6). In Figure 7, after the landslide mass starts
yielding, dL 2 / dL1 becomes less steep for wider soil masses. This can be
explained as follows: This dL 2 / dL1 , when multiplied by the cross-sectional
area of the landslide mass, is identical to − dV 2 / dV 1 , where dV 2 and dV 1 aresoil volumes which pass through the cross section per unit time forsegments L 2 and L1 , respectively.
The soil volume dV1 will be pushed forward over the deposition zoneby the following soil volume dV1 , while the volume of dV 2 − dV 1 is pushed
up and/or sideways making a bulge at around the toe of the slope. It is thus
clear that, less steep dL 2 / dL 1 indicates larger confinement of dV 2 − dV 1
causing slight increase of F even after the initial ultimate capacity F wasreached. In other words, the effect of confinement can be quantitatively
estimated from geometry of the deformed landslide mass. Width of alandslide mass can also affect F .
As the width increases, the curve converges on the plane-strain
solution, while it is rather closer to plane-stress solution for thinner soilcases. The ultimate load capacity F would be more crucial in determining
its distal reach. In this research, by analysis on different width of theLandslide movement and deformation for different length and width of landslide mass

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October 2009, Incheon, Korea

landslide, as the confining pressure is increasing, peak stress is increasing; it
becomes a phenomenon similar to tri-axial compression tests.
Flat

Slope (20 deg)

Figure 6:Plane view of height of landslide mass for different width(time = 15s)

W:
L1y
L2[m]

Plane
strain

Cross
foot

σa σa
L1[m]

L2[m]

L1[m]

Figure 7: L1 and L2 for different width of landslide mass

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New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSION
This research introduced some results for extracting important pieces of
information for landslide risk assessment from numerical model and reallandslide masses. For coherent mass movements, numerical simulation oflandslide mass movements using Material Point Method (MPM) gave an
idea for extracting parameters from real land slide masses. A real cohesive
landslide can be viewed as a large-scale specimen of a monotonic loading
test for obtaining its ultimate load capacity F , which can be greatly
responsible for distal reach of the landslide mass. And also, the coefficientof sliding surface that is one of the important parameter to define run-out
distance on the deposit zone is difficult to be evaluated from real site. For
that one possible approach is proposed in this research. This knowledge will
provide a good perspective for landslide risk assessments.

REFERENCE
Sulky, D., Chen, Z. and Schreyer, H.L. (1994): A particle method for history
dependent materials, Computer methods in applied mechanics andengineering, 118, pp. 179-196.
Konagai, K. and Numada, M. (2002): Pseudo-three dimensional lagrangianparticle finite difference method for modeling long-traveling soil flows,
Journal of Dam enginnering, 12(2), pp. 123-128.
Numada, M., Konagai, K., Ito, H. and Johansson, J. (2003): Material point
method for run out analysis of earthquake-induced long-traveling soil flows,
Journal of Earthquake Engineering, 27.

Landslide movement and deformation for different length and width of landslide mass

85

CASE STUDIES OF COASTAL EROSIONCONTROL BY GEOTEXTILE TUBE
1

1

Eun Chul Shin, 1Sung Hwan Kim and 2Young Keun Lim
Department of Civil and Environmental Engineering, University of Incheon,
Korea, ecshin@incheon.ac.kr, sherikim315@naver.com
2
Department of Geomarrine Systems, Korea, limyg2005@empal.com

ABSTRACT
Recently, because of the shortage of natural rock, traditional forms ofriver and coastal structures have become very expensive to built and to be
maintained. Therefore, the materials used in hydraulic and coastal
structures are changing from the traditional rubble and concrete systems to
the cheaper materials and systems. Also, geotextile tube technology haschanged from being an alternative construction technique and, in fact, hasadvanced to become the prime solution of choice. This paper presents thestability analysis and field monitoring results of stacked geotextile tube
structure for temporary construction platform, the various issues related to
the geotextile tube technology and case history of shore protection of Korea,
Republic of Korea. Geotextile tube was proposed for desired crest height,
and the stability analysis against external force was conducted to the eachcross section of stacked geotextile tube. The considered external forces arewave force, tidal force and lateral earth pressure by reclamation.

1. INTRODUCTION
Erosion problems in coastal zones are become increasingly serious due tothe development of artificial activities related to the expansion of city
functions, industrial complexes and harbor facilities, as well as the removalof sea sand for use in aggregate resources at the construction sites, which isa major factor in the inflow and outflow of sea sand. In addition, theenvironmental and economical importance of the coastal beach zones isincreased. However, coastal beach zones are constantly eroded by waves
accompanied with the rising water level due to storm surges, hurricanes,
winter storm impact, and high tide. This erosion motion accelerates theregression of the coastal cliff due to the regression of the dunes or the
shoreline. In addition, the regression leads to loss of real estate in thehinterland and ruins the shock-absorbing zone between land and sea.
Therefore, the destruction of the dunes may lead to a loss of the habitat or
egglaying grounds of living creatures. In addition, the erosion motion ofcoastal beach zones destroys the living sites of inhabitants who live incoastal beach zones, and the erosion problem harms the local economy bydecreasing the number of visitors. For these reasons, concern is increasing
for the protection of coastal beach zones. Many nations are striving toprevent damage to such zones, as are private organizations and local

87

October 2009, Incheon, Korea

selfgovernments. One such preventive effort is beach nourishment or
construction of the coast structures. Geotextile containment such as small
sand bag has been adopted for the construction of civil structures in the past,large volume geotextile containers are being applied widely in considerationof economical and easy installation, and also for the minimization ofenvironmental effects. Especially, contaminated soil and sediments dredged
from port area are utilized to fill in geotextile containment for reclamation.
Geotextile containment is widely classified into geotextile bag, geotextile
tube and geotextile containment, and they are filled with soil to be shaped ofstructure. The filling method is normally hydraulic filling by means ofpumping, and also mechanical method can be applied according to the site
condition. This technology can be applied for the sea shore embankment,
embankment core material, embankment enforcement and disaster recovery
construction. For environmental application, it can be used for embankment
construction to recover and preserve swampy land and dredging reclamationof deep sea contaminated accumulated earth sand. In case of conventionalstone and concrete sea shore structures, they accompany large scale
environment destruction. However, the construction using this technology
does not accompany environment destruction. In particular the materials
that may contaminate the environments in sea shore, recovered swampy
land and embankment can be used as a filter. Therefore, it is an excellent
technology that can bring dual advantages to the environment. Additionally,
as it uses the deep sea sand on the site rather than the expensive goodquality sand, this technology saves a lot of money. Furthermore it will bringthe additional cost saving through shortening the construction period
because of the easy application.

2. CONSIDERATED CONTENT FOR CROSS-SECTION DECISION
Formulation of a geosynthetic tube, filled with pressurized slurry or fluid, isbased on the equilibrium of the encapsulating flexible shell. The results ofthis formulation provide both the circumferential tensile force in and thecylindrical geometry of the encapsulating shell material. It should bepointed out that the formulation appears in numerous articles (e.g., Liu 1981,
Kazimierowicz 1994, Carroll 1994). For the sake of completeness, only an
overview of the basic formulation is reproduced later. Refer to Figure 1 fornotation and convention. For clarity of presentation, the tube considered issurrounded by air and is filled with only one type of slurry. However,extension of the formulation to include layers of slurry inside and layers of
fluid outside, is straightforward. Note that the cross section is symmetrical,
having a maximum height of h at the centerline, maximum width B, and aflat base that is in contact with the foundation soil and is b wide. Theppumping pressure of the slurry into the tube is 0 . The average unit weight(density) of the slurry is γ . Hence, the hydrostatic pressure of the slurry at
any depth x, as measured from point O, is p ( x) = p0 + γ x .

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 1:Cross-Sectional View of Geosynthetic Tube
The geometry of the geosynthetic shell is defined by an unknown functiony=f(x). At a point of contact S(x,y), the radius of curvature of thegeosynthetic is r. The center of this curvature is at point C(xc,yc). Both r andC vary along y(x). Consider the forces on an infinitesimal arc length, ds, ofthe geosynthetic at S. Since it is assumed that the problem is twodimensional and that no shear stresses develop between the slurry and thegeosynthetic, it follows that the geosynthetic tensile force, T, must be
constant along the circumference. Assembling the force equilibrium
equation in either x or y direction leads to the following relationship:T(1)
γ ( x) =p( x)Equation 1 is valid at any point along A1OA2. To simplify the analysis, it isassumed that the calculated T from Equation 1 is carried solely by thegeosynthetic along the flat base b. That is, no portion of T is transferred to
the foundation soil due to shear along the interface between the geosynthetic
and soil. The tube in the z-direction(i.e., axial direction) carries the force P.
T
The force axial per unit length then is P divided by the circumference, L, of
the tube. That is:
T a x ia l =k2• ∫ ( p0 + γ • x) • y ( x)dx
0
L

CASE STUDIES OF COASTAL EROSION CONTROL BY GEOTEXTILE TUBE

(2)

89

October 2009, Incheon, Korea

Typically, the circumferential force T is larger than Taxial . Hence, if theTgeosynthetic having isotropic strength is considered, the value of axial is notneeded in design. However, frequently geosynthetics are anisotropic; i.e.,their strength in the warp direction (usually corresponds to the tube's
circumferential direction) is different than that in the fill direction (usuallycorresponds to the tube's axial direction). This anisotropy is particularlycommon in medium to high strength geotextiles, where different types andnumber of yarns per unit width are used in each of the principal directions in
the fabrication process. The end product may have either significantly
higher or worse, lower strength in the axial direction as compared to thecircumferential one. Consequently, to assure economical selection of ageosynthetic, producing a safe structure, the value of Taxial should always beTconsidered. Program GeoCoPS provides the values of both T and axial .
These values are adjusted by user-prescribed reduction factors that accountfor the reduction in geosynthetic strength due to seams and possible
construction damage. The end result allows for the selection of an adequate
geosynthetic.

Figure 2: Axial Tensile Force in Geosynthetic Tube

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: Geosynthetic Tube Install Procedure

3. PARAMETRIC STUDY ANALYSIS AND RESULT
To realize how sensitive the solution for the geosynthetic tube is withrespect to the design parameters, a parametric study was conducted. This
instructive study was conducted using program GeoCoPS. For all cases, thecircumference of the tube was chosen as L= 9.4m(GTD 300), the unit
weight of slurry relative to water was taken as 1.2, no water, 1.0m, 1.5m,
2.0m, 2.5m outside the tube was considered, and all safety factors on
geosynthetic strength were set to default value.

Figure 4: Effects of Tult, on Geometry of Tube (outside water = 2.5m)
Figure 4 shows the effects of the specified tensile force of the geosynthetic
on the geometry of the tube. To get a perfect circular cross section, having a
diameter equal to D=L/π=9.42m(GTD=300), the required T must approachinfinity. Figure 5 illustrates the effects of a designed height h on the

CASE STUDIES OF COASTAL EROSION CONTROL BY GEOTEXTILE TUBE

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October 2009, Incheon, Korea

geometry of the tube. For a desired height of 1.65m (about 55% of D), therequired pumping pressure is nearly zero, and required circumferential force
is only 8.9kN/m. however, for a desired height of about 90% of D (h=2.7m),
the required pumping pressure is about 13.3kPa, and the required
circumferential force is substantially larger, approximately 98.3kN/m.

Figure 5: Effects of h on Geometry of Tube (outside water = 2.5m)

3.0

3.0

2.5

2.5

2.0

1.5

1.0

Outside water 2.5m
Outside water 2.0m
Outside water 1.5m
Outside water 1.0m
No outside water

0.5

0.0
0

5

10

15

20

Height of Tube, h (m)Height of Tube, h (m)Figure 6 demonstrates the relationship between the height of the tube andthe pumping pressure. It can be seen that p0 is most significant at low
pressures; as the pressure increases, its effect on h becomes negligible. At apumping pressure of 20kPa, 90% of the theoretical height is achieved. In
fact, the relationship approaches an asymptote of h=D that will be metonly
when p0 is at infinity

25

Pumping Pressure, P0(kPa)(a) At design tensile strength

2.0

1.5

1.0

Outside water 2.5m
Outside water 2.0m
Outside water 1.5m
Outside water 1.0m
No outside water

0.5

0.0
0

10

20

30

40

50

Pumping Pressure, P 0(kPa)(b) At design height

Figure 6: Height of Tube versus Pumping Pressure
Figure 7 illustrates between ultimate tensile strength and the pumping
pressure. For the selected parameters in the parametric study, it can be seenthat as p, decreases, the ultimate tensile strength approaches the value ofzero. This figure is particularly instructive in the context of design; it
illustrates the potential economy when selecting a geosynthetic having ananisotropic strength that corresponds to both tensile forces T and Taxial whenthose are significantly different. Since these strengths must develop throughthe seams, one can also realize the critical importance of seam strength andefficiency.

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New Technologies for Urban Safety of Mega Cities in Asia

350

Outside water 2.5m
Outside water 2.0m
Outside water 1.5m
Outside water 1.0m
No outside water

150

Ultimate Tensile stength, Tult(kN/m)

Ultimate Tensile stength, Tult(kN/m)

200

100

50

0
0

5

10

15

20

Outside w ater 2.5m
Outside w ater 2.0m
Outside w ater 1.5m
Outside w ater 1.0m
No outside w ater

300

250

200

150

100

50

0

25

0

10

Pumping Pressure, P 0 (kPa)

20

30

40

50

Pumping Pressure, P 0 (kPa)(a) At design tensile strength(b) At design height

Figure 7: Tult versus Pumping Pressure
Finally, Figures 8 show the relationship after consolidated height of tube thepumping pressure. At a pumping pressure of 15kPa, for a desired height of
1.2m (about 40% of D), the required pumping pressure is nearly zero. A flat
top geometry will render the mathematical solution of the problem ofpressurized slurry tube invalid. As reduced slurry unit weight decreased
after consolidated height of tube Hf. This approximate procedure allows fora rough estimate of the average drop in height, once a supposed density offill material is achieved. Also, if the filling ratio is at least up to 80%, theimmediate settlement is negligible because geotextile confined the fillmaterial by highly developed tension in geotextile. However, the long-term
consolidation of whole geotextile containment bund is more complicatedphenomena, there has a single unit behavior and stacked surcharge loading
relationship. Therefore, the long-term deformation of geotextile containment
bund was need more strict quality control during and after bund construction
by field monitoring such as settlement cell, pore pressure transducer andother sea bed scanning systems.
1.6

1.2

1.0

0.8

0.6

0.4
3

Slurry unit weight, rslurry=14kN/m

0.2

3Slurry unit weight, rslurry=16kN/m

After consolidated height of Tube, hf (m)After consolidated height of Tube, hf (m)

1.4

1.4
1.2
1.0
0.8
0.6
0.4
3

Slurry unit weight, rslurry=14kN/m

0.2

3Slurry unit weight, rslurry=16kN/m

3

Slurry unit weight, rslurry=18kN/m

0.0
0

5

10

15

20

3

Slurry unit weight, rslurry=18kN/m

0.0
0

Pumping Pressure, P0(kPa)

10

20

30

40

50

Pumping Pressure, P0(kPa)(a) At design tensile strength(b) At design height
Figure 8: After Consolidated Height of Tube at Given Pumping Pressure

4. MONITORING OF DEFORMATIONTo check variation of shape, deformation, and other condition of thegeotextile tube, it shall be surveyed a right angle to the shoreline fromdatum point of location of geotextile tube. The survey of water shape,
deformation, and other condition shall be carried out by diver inspection(video camera), hydrographic method, side scan sonar apparatus on

CASE STUDIES OF COASTAL EROSION CONTROL BY GEOTEXTILE TUBE

93

October 2009, Incheon, Korea

monitoring boat, and it shall be repeated to reduce the scope of error forcorrect location. 3-D Echo Sounder and GPS system is recommendable assounding apparatus which has capacity to survey up to 100 meter's deep andthe distance of movement(See Figure 9). Also, the pneumatic settlement cellshall be used.

Figure 9: Illustrate Echo-Sounder Apparatus and Surveying Scene

5. CONCLUSION REMARK
An overview of analysis to calculate the geometry and stresses of ageosynthetic encapsulating pressurized slurry has been presented. The
validity of the resulting equations was verified against the numerical andexperimental results obtained by other investigators. Parametric studies
indicate that stresses in the encapsulating geosynthetic are very sensitive at
the pumping construction stage, it is extremely important to safeguard
against accidental increase in the slurry pumping pressure. The parametricstudies also reveal that a significant increase in pumping pressure will only
slightly increase the tube’s cross-sectional area and, hence, its storage
capacity. A guide to selecting a geosynthetic is provided. It is based onpartial safety factors. These safety factors address the seam strength,
potential installation damage.(i.e., accidental increase in pumping pressure),
accelerating creep, and possible chemical and biological degradation. Also
addressed is the required permeability of particles. Finally, a simple
procedure to assess the final height of a tube filled up with clayey slurry is
proposed. It should be pointed out that complete design of geosynthetic
tubes has to also include the head loss occurring as the slurry flows awayfrom the inlet. This aspect of design that will determine either the maximum
length of a tube of the distance between inlets along that determine either
the maximum length of a tube or the distance between inlets along the tube
has not been addressed. Thought empirical rules dealing with this aspect
exist, a rational analytical procedure is needed. Also, the measurement
during construction for geotextile Tube is classified by 3 items. The first
item is monitoring of individual geotextile tube unit for management offilling and dumping process, the second item is deformation monitoring of
lumped geotextile tube for local stability, the last item is monitoring of
geotextile tube bund for overall stability.

94

New Technologies for Urban Safety of Mega Cities in Asia

REFERENCES
Shin, E. C., Oh, Y. I. 2004, Consolidation Process of Geotextile Tube Filledwith Fine-grained Material, International Journal of Offshore and Polar
Engineering, Vol. 14, No. 2, pp. 120-158
Shin, E. C., Oh, Y. I. 2004, Using Submerged Geotextile Tube in theProtection of E. Korean Shore, International Journal for Harbour andOffshore Engineers, Volume 53, No. 11, pp. 879-895
Shin, E. C., Oh, Y. I. 2007, Coastal Erosion Prevention by Geotextile Tube
Technology, Geotextiles and Geomembranes, Vol. 25, No. 4, pp. 264-277
Horace, M. Y., Meyers, T., Townsend, D. 1998, Evaluation of Geosynthetic
Fabric Containers to Contain Contaminated Dredged Sediment, Proceedingsof Sixth International Conference on Geosynthetics, Atlanta, Georgia, USA,
Vol. 2, pp. 1173-1176.
Gibson, R. E., England, G. L., Hussey, J. L. 1967, The Theory of OneDimentional Consolidation of Saturated Clay, Finite Non-Linear
Consolidation of Thin Homogeneous Layers, Geotechnique, Vol. 17, pp.
261-273.
Koerner, R. M., and Koerner, G. R. 1996, Geotextiles Used as Flexible
Forms, Geotextiles and Geomembranes, Vol. 14, No. 6, pp. 301-311.
Koerner. R. M. 2000, Emergind and Future Developments of Selected
Geosynthetics Applications(The thirty second Terzaghi Lecture), Journal of
Geotechnical and Geoenvironmental Engineering, ASCE, Vol. 126, No. 4,
pp. 291-306.
Leshchinsky, D., Leshchinsky, O., Ling H. I., Gilbert, P. A. 1996,
Geosynthetics Tubes for Confining Pressurized Slurry: Some Design Aspect,
Journal of Geotechnical Engineering, ASCE, Vol. 122, No. 8, pp. 682-690.
Pilarczyk, K. W. 1997, Application and Design Asptects of Goecontiners,
Proceedings of Geosynthetics '97 Conference, Long Beach, CA, IFAI, St.
Paul, MN, pp. 147-160.
Pilarczyk. K. W., Breteler, M. K., Stoutjestijk, T. 1998, Stability Criteria for
Geosystems -an Overview-, Proceedings of Sixth International Conference
on Geosynthetics, Atlanta, Georgia, USA, Vol. 2, pp. 1165-1172.
Welsh, J. P., Koerner, R. M. 1979, Innovation Use of Synthetic Fabric in
Coastal Construction, Coastal structures, Journal of GeotechnicalEngineering, ASCE , Vol. 1, pp. 364-372.

CASE STUDIES OF COASTAL EROSION CONTROL BY GEOTEXTILE TUBE

95

Cross-boundary Water Resources
Adaptation: Comparing a watershed
approach and a political unit approach
AKIYUKI KAWASAKI1, PETER ROGERS2SRIKANTHA HERATH3 and KIMIRO MEGURO1
1
IIS, The University of Tokyo, Japan
2
Harvard University, USA
3
United Nations University, Japanakiyuki@iis.u-tokyo.ac.jp

ABSTRACTThe Man-made boundaries such as national borders are typicallyused as the unit for considering river-basin management and policy, while
natural boundaries such as watersheds are propounded as a promising
approach for environmental management. However, few studies have
proven the latter’s utility by comparing the two approaches based onpractical analysis with local data. This study investigated the utility of two
approaches, a “watershed” and a “political unit (a national or provincial
boundary)” approach, for water resources adaptation in cross-boundary
sub-basins by investigating a range of climate-adaptation strategies forcooperation among the riparian nations. By investigating the results of eachapproach, a suitable adaptation strategy for a specific area was assessed
and the general advantages and disadvantages of each approach in likely
scenarios were demonstrated. The Mekong River basin, fed by the longest
international river in the Asia, is the study area. We will show by the use of
geospatial technology and hydrological simulation how conflict andcooperation for climate adaptation in a cross-boundary river-basin would
be viewed in the light of game theory, and then use this technique tocompare the watershed approach and the political unit approach.
This study’s innovative, robust methodology for solving complex
cross-boundary river-basin issues would be a basis for local policy
decision-making and research for climate adaptation and urban andregional planning in the Mekong River and beyond. The characteristics ofstudy areas and initial discussion of this study as well as analysis process
are described in this paper.

1. INTRODUCTION
Developing a scientific framework for cross-boundary water resourcesmanagement is urgently required as available fresh water becomescompetitive, and thus causes more conflicts over water, due to both
population growth and climate change. Conventionally, river-basin policy is
divided by man-made boundaries such as national borders (Beach 2000;

97

October 2009, Incheon, Korea

Rogers 1969; Rogers 1993; Rogers and Kung 1985), although many havecalled for better environmental management through natural boundaries
such as watersheds, the area of land where all of the water that is under it ordrains off of it goes into the same place (Millennium Ecosystem Assessment
2005; US EPA 2009). This approach would capture most externalities in theriver basin, but it is politically problematic, since all of the riparian nations
must agree on those externalities. Solid research should inform the policy
makers, however, few studies, have proven the utility of the watershed
approach by comparing it to the traditional national border approachthrough practical analysis based on local data. This research will investigate
the use of the watershed and political unit approach, for water resources
adaptation in cross-boundary sub-basins by investigating a range of climateadaptation for cooperation among the riparian nations. By investigating theresults of each approach, we hope to demonstrate their advantages anddisadvantages in likely scenarios, and discuss how a desirable solution canbe derived.
The main tool we used for this study is a Geographic Information
System (GIS), which is a promising tool for integrated river-basin analysis
and management. In particular, we will use the Arc Hydro data model(Maidment 2002), a spatial and temporal data model for water resources, tomodel the water flow from upstream to downstream. We will show by theuse of geospatial technology and hydrological simulation how conflict andcooperation for climate adaptation in an international river-basin may beviewed in the light of game theory, and then use this technique to compare
the watershed approach with the political unit approach. The characteristics
of study areas and initial discussion of this study as well as analysis process
are described in this paper.

2. STUDY AREA
2.1

Overview of the 3S basin

The 3S basin, named after the three sub-basins it contains (theSekong, Sesan and Srepok), is part of the Lower Mekong River Basin on the
Indochinese Peninsula and includes land in Cambodia, Lao People’s
Democratic Republic (Lao PDR), and Vietnam (Fig. 1). The 3S area is thelargest tributary system of the Mekong River Basin (Mekong River
Commission 2007). It covers about 10% of the area of the entire Mekong
Basin and contributes 17% of the total run-off (World Bank 2006). The
Mekong River Commission (MRC)’s Basin Development Planning project(2009) identified the area as a region where considerable development
potential exists and as a result, multilateral development banks have been
investigating it. World Bank (2006) studied the water resources assistancestrategy for integrated development and management. The AsianDevelopment Bank has been supporting arrangements to strengthen regionalcross-border collaboration at the request of the National MekongCommittees (NMC) of the governments of Cambodia, Lao PDR, and Viet
Nam since April 2006.

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New Technologies for Urban Safety of Mega Cities in Asia

The precipitation varies regionally across the 3S, ranging from about
1,500mm in the downstream areas and middle reaches of the Srepok togreater than 3,000mm in the upstream portions of the Sekong and Sesan
sub-basins.
Much of the development in the 3S area is related to the design andconstruction of hydropower plants. As of February 2009, 9 hydropower
plants were in operation, 8 were under construction and 24 were still indesign or planning stages (Asian Development Bank 2009). The 78,650km2
study area is divided between the three countries, with 29% of the area in
Laos, 33% in Cambodia and 38% in Vietnam. In relation to its large area thetotal population is low, about 2,700,000 in 2000 and 2,900,000 in 2004, but
the population growth rate is much higher than average in each country. The
values of area and population by countries within the entire Mekong Riverbasin and within the 3S area are shown in table 1. The social and economic
development and resulting environmental pressures are higher in the
upstream than the downstream regions. Detailed characterizations of each
sub-basin are given in following section.

Figure 1: Three cross-boundary sub-basins in the Lower Mekong River
Basin, Sekong, Sesan and Srepok (the 3S), cover the three national bordersof Lao PDR, Cambodia, and Vietnam in the Indochina Peninsula.
2.2 Characteristics of individual sub-basins
2.1.1 The Sekong River s
The Sekong is the only sub-basin of the Mekong including lands fromthree countries. Seventy eight percent of the area is in Laos, 19% in
Cambodia, and 2% in Vietnam. The basin area in Laos, despite covering amajority of the area, have very few population, though the Vietnamese
territory is very small it accounts for 18% of the population in the basin. As
a whole, population density in the Sekong basin is by far lowest of the three:11.5 persons/km2 in 2000.
Hydropower dam development is not very active in comparison to theother two sub-basins; only one plant, located in Laos in the middle of the

Cross-boundary Water Resources Adaptation: Comparing a watershed approach and a political unit approach99

October 2009, Incheon, Korea

sub-basin, is currently in operation. However, three relatively large scalehydropower plants (total 572MW) are under construction, and if all theplants now in design or master plans stages are actually built this sub-basin
will be the most developed in the 3S, in terms of both number ofhydropower plants (20) and installed capacity (total 2,688MW). The
planned developments are all located in Lao territory in the middle andupstream region of the sub-basin. If all of these plants are constructed thispart of the sub-basin will hold the largest active storage (total 11,067MCM)
in the 3S. This development, in combination with changing land-use
patterns upstream, may threaten the water use in the downstream
Cambodian territory.
Table 1: Area and population by countries within the entire Mekong Riverbasin and within the 3S area.
Area(103km2)
Cambodia
Lao PDR
Vietnam
Total

155/ 25
202/ 2265/ 30422 / 77

Current population(million)
14.6 (2007) / 0.28 (2004)
6.2 (2007) / 0.22 (2004)
22.2 (2006) / 2.4 (2004)
65.7 / 2.9

Annual Growth
Rate (%)

Population in2020 (million)

2.5 / 2.99
2.9 / N/A
1.3 / 1.95
2 / N/A

20.1 /0.34
7.7 / N/A
25.6 / N/A
77.8 / N/A

2.1.2 The Sesan River
Hydropower plant development is currently most advanced in the
Sesan River basin. Five plants, with a total installed capacity of 1,177MW
are now in operation. One plant, with a capacity of 360MW, is underconstruction and five, totaling 1,033MW of installed capacity,, are in thedesign or master plan stage.. Many reports and documents, especiallyinvestigating fishery issues, have been written about this sub-basin, due inpart to recent interest in trans-boundary issues (Hirsch 2004; Ian G. Baird
2005; Nam 2006).
The total active storage of existing and planned hydropower plants(5,919 MCM) is small relative to other two sub-basins (11,067 MCM for
Sekong, and 9036 for Srepok), which might translate into a relatively small
impact on water use in the downstream Cambodian territory. However,since 90% of population of the sub-basin is in Vietnamese territory with ahigh rate population growth, the corresponding increase of water use might
still threaten the downstream areas.
2.1.3 The Srepok River
Two small hydropower dams (total installed capacity 28MW) are in
operation in the middle of the Vietnamese side of the Srepok basin. Four
plants are under construction (total 656MW) and three plants are part of themaster plan (total 396MW). Compared to other two sub-basins the totalplanned installed capacity is small (total 1,080MW), but the total active
storage is estimated to achieve over 9,000 MCM. More than 80% of the
population lives in the Vietnamese part of the basin and a rapid increase ofwater use corresponding to population increase and expansion of agricultureon the Vietnamese side are projected in this sub-basin (Kawasaki et al.
2009). This may cause higher pressure on water resources and the100

New Technologies for Urban Safety of Mega Cities in Asia

environment in the relatively sparsely populated areas on the Cambodianside of the basin.
Poverty remains high in the Central Highlands of Vietnam,
particularly the southeastern part of the basin. In the past 25 years, a
constant influx of settlers into the sub-basin from other parts of Vietnam has
resulted in an increase in transient poverty (World Bank 2006). The climate
and hydrological data and documentation available for this sub-basin tends
to be relatively abundant and of higher quality, particularly for theVietnamese side, where the water resources development and management
infrastructure is more advanced than in the surrounding areas.

3. METHODOLOGY
We will show by the use of geospatial technology and hydrologicalsimulation how conflict and cooperation for climate adaptation in a crossboundary river-basin may be viewed in the light of game theory, an analytic
method for describing such conflicts and for clarifying the issues at stake.
Then, we will use this technique to compare the watershed approach and thepolitical unit approach. The main tool we will use for this study is a
Geographic Information System (GIS). Details are described as follows.
3.1 Method
3.1.1 Analyzing the characteristics of sub-basins.
To historical trend of land-cover change in this area, comparison of theland-cover area between 1997 and 2002/2005 are described at Table 2.
Assumed upstream countries impact on downstream country is analyzed atTable 3 to illustrate the relationships among sub-basins in the 3S area.
3.1.2 Investigating future available water
Streamflow in the next several decades, until 2025 and 2050, will besimulated by considering the potential impacts of climate change and socioeconomic development on water supply and demand from domestic,
agricultural and industrial uses. Various scenarios such as “business as
usual”, “minimum” and “maximum” development, and “extreme climatechange” will be incorporated for building future land-use and precipitation
models by integrating the IPCC (Intergovernmental Panel on Climate
Change) climate scenarios (2007).
We have already developed an experimental hydrological model in the
Mekong (Kawasaki et al. 2009). By calibrating my simulations to landuse/water-use changes that have occurred in the past, we will sophisticate
our model for a policy-making support.
3.1.3 Considering water resources adaptation strategies
Possible water resources adaptations will be proposed for eachscenario and each sub-basin in light of simulated stream flows and local
characteristics. Adaptation involves the following types of activities:
investment planning for new or expanded infrastructure (reservoirs,
irrigation systems); maintenance and major rehabilitation of existing

Cross-boundary Water Resources Adaptation: Comparing a watershed approach and a political unit approach101

October 2009, Incheon, Korea

systems (dam safety, levees); modifications in processes and demands(water conservation, pricing, regulation); and introduction of new efficienttechnologies (drip irrigation, reuse, recycling). In this process, we will haveintensive interviews and discussions about the likely future development
scenarios, adaptation strategy and its impact on geopolitics with the experts
especially scholars in international politics, environmental politics, public
policy and development economics.
Table 2: Comparison of the land-cover area between 1997 and 2002/2005
Seson
SrepokSekong
2005
2005
1997
2005
1997
15,841 70% 13,767 61%
1,753 8% 1,397 6%
10 0%
905 4%
443 2%
0 0%
4,503 20% 6,493 29%
5,126 92% 4,369 79% 6,310 83% 4,585 60% 10,620 83% 10,228 80%
183 3%
175 3% 770 10%
835 11%
486 4%
531 4%
0 0%
5
0%
3 0%
5 0%
2 0%
8 0%
6 0%
104 2%
15 0%
144 2%
69 1%
191 1%
187 3%
825 15% 438 6% 1,675 22% 1,514 12% 1,653 13%
394 57%407 59% 6,088 54% 5,789 51% 8,991 50% 6,875 38%
67 10%
39 6% 2,937 26% 2,122 19% 6,116 34% 6,793 37%
0 0%
0 0%
18 0%
0 0%
6 0%
0 0%
34 5%
0 0% 696 6%
0 0%
446 2%
0 0%
13%
25%
35%
27%
29%
172
242
3,028
3,268
2,442
4,433 24%

Vietnam

Cambodia

Laos

1997

ＦorestAgriculture
Urban area
Grass land
Open land
ForestAgriculture
Urban area
Grass land
Open land
ForestAgriculture
Urban area
Grass land
Open land- Area unit is km2- Percentage shows the areal portion of each country within the basin.
Table 3: Assumed upstream countries impact on downstreamt Sekong(Viet, Lao-->Cmb) Sesan (Viet --> Cmb) Srepok (Viet --> Cmb)
Assumed impact
Population
×: Very small change in △: Large increase in◎: Large increase inincrease
upstream Laos where
upstream Vietnam where upstream Vietnam where(Domestic water dominate more than 70% dominate about 90%
dominate about 95%
demand)population in the subpopulation with 0.7
population with 1.7
basin
million in the sub-basin
million in the sub-basinLanddevelopment(agriculture andindustry)○: Rapid change inforest and open land
between 97 and 05. Still
has the large potential.

HEP storage◎: Only 1 HEP is
operation now, but
11,067MCM active
storage HEPs are plannedin Laos

×: Small change of land ○: Rapid change inforest and open land
cover in upstream
Vietnam between 97 and between 97 and 05. Still
05. Not so high potential has the large potential.
for large development
because of precipitous
terrain○: 2,129MCM active△: 1,026MCM active
storage are operated and storage are operated andplanned in upstream
planned in upstream

Installed capacity (both in operation and planned)◎: 2,688MW HEPs n◎： 1,736MW in Vietnam △: 733MW in Vietnam
HEP capacity
Laos
784MW in Cambodia
347Mw in Cambodia

102

New Technologies for Urban Safety of Mega Cities in Asia

Then, both a political and a natural boundary approach will besimulated. Water quantity and net benefits (normalized to dollars) will be
the criteria for comparison. Several strategies will be considered, such as inthis simple two country example:
Case 1: Both Vietnam and Cambodia do nothing;
Case 2: Vietnam optimizes, Cambodia does nothing;
Case 3: Both optimize independently;
Case 4: Regional optimization with distinct sub-regional budgets;Case 5: Regional optimization with a single regional budget.
3.1.4 Comparing strategies
We are faced with the dilemma of how to select the best strategy forthe development of the region. For example, choosing case 5 as yielding thehighest overall net benefits to the region might not satisfy Vietnam, who
would do better in case 3. For Cambodia, however, case 3 is much lessattractive than case 5. Luce and Raiffa (1989) would describe these conflicts
as a “cooperative two-person nonzero-sum game”.
When we have three countries, we use the theory of the core fromgame theory. Suitable water resources adaptations for the study area will be
discussed by comparing various adaptation strategies in both a watershed
and a political unit.
3.2 Data
Availability of hydro and climate data in the study area is as follows.
18 hydrological observation data are available in the 3S sub-basins form the
Mekong River Commission Secretariat database. All the stations records
daily water level in some periods of years such as some records data in
1910-1970 and other records only after 2000. However, only 7stations
record daily discharge from 1990’s.
Regarding land-cover data, a variety of maps and datasets have been
produced showing vegetation types and extent of forest cover in Cambodia
however there are discrepancies in the forest cover percentages between
these. The wide variety of forest cover figures can be attributed to factors
such as incomparable data generation methods, lack of backgroundknowledge on the analyst’s past and lack of funds or time (MRC 2003). For
more detailed information, please refer to Forest Trends.
The selection of Forest Resource maps in the atlas intends to give an
overview o f the forestry sectors in Cambodia including information onvegetation types, trends, non timber forest products and management
approaches. Explanations of the methodology used and limitations inregards to data collection are given in the appropriate sections throughout
the chapter.

4. FUTURE WORKIn this paper, the characteristics of study areas and initial discussion of thisstudy as well as analysis process are described. The result of this study will
be described at another paper in near future. Then, we will visit stakeholders

Cross-boundary Water Resources Adaptation: Comparing a watershed approach and a political unit approach103

October 2009, Incheon, Korea

in environmental policy making in the Mekong River Basin to discuss thevalidity of our research results. The scope of these interviews will be
confined to four of the countries in the Lower Mekong: Cambodia, Laos,
Thailand and Vietnam (we would like to include China and Myanmar if
possible). Their feedback will be taken into account for modifying models
and methodologies and refining the proposed adaptation strategies.
Planned organizations to visit include: National and local authorities
in the four countries, a joint panel of the regional nations (Mekong River
Commission), local offices of multilateral development banks (World Bank,
Asian Development Bank), nongovernmental organizations such as the
Mekong Watch, and local academic institutes for the Mekong study such as:
Asian Institute of Technology, Thailand; National University of Laos, Laos;and Can Tho University, Vietnam.

ACKNOWLEDGEMENT
We are grateful to Ms. Janet He and Ms. Julie Malakie for their dedicatedwork to conduct the simulations in this study. Also, we appreciate Dr.
Masatsugu Takamatsu, for his valuable support for hydrological simulation.
This study was supported financially by Research Fellowships of the Japan
Society for the Promotion of Science for Young Scientists.

REFERENCES
Asian Development Bank. 2009. Sesan, Sre Pok and Sekong River Basins
Development Study in the Kingdom of Cambodia, Lao People's Democratic
Republic and Socialist Republic of Viet Nam, TA6367 (REG): Pilot testing
IHA-SGAP in the 3Ss Basins Inception Report.
Beach, H. L., Hamner, J., Hewitt, J. J., Kaufman, E., Kurki, A.,
Oppenheimer, J. A., and Wolf, A. T., 2000. Transboundary Freshwater
Dispute Resolution: Theory, Practice, and Annotated References, United
Nations University Press, Tokyo, New York, Paris.
Hirsch, P., A. Wyatt., 2004. Negotiating local livelihoods: scales of conflictin the Se San River basin. Asia Pacific Viewpoint, 45 (1), 51-68.
Ian G. Baird, M. M., 2005. Sesan River Fisheries Monitoring in Ratanakiri
Province, Northeast Cambodia: Before and After the Construction of theYali Falls Dam in the Central Highlands of Viet Nam. 3S Rivers Protection
Network (3SPN), Ratanakiri Province, Cambodia.
Intergovernmental Panel on Climate Change (IPCC), 2007. Fourth
Assessment Report: Climate Change 2007.
Available at: http://www.ippc.ch/ipccreports/ar4-syr.htm.
Kawasaki, A., Takamatsu, M., He, J., Rogers, P., and Herath, S., 2009.
Evaluation of local water resources adaptation to climate change: the Srepok
River Basin in Vietnam and Cambodia. Journal of Water Resources
Planning & Management, in review.

104

New Technologies for Urban Safety of Mega Cities in Asia

Maidment, D. R., 2002. Arc Hydro: GIS for Water Resources, ESRI Press,
Redlands, California.
Luce, R., Raiffa, H., 1989. Games and Decisions: Introduction and critical
Survey, New York: John Wiley, chapter 6.
Mekong River Commission. 2007. Diagnostic study of water quality in theLower Mekong Basin: MRC Technical Paper No. 15. Vientiane, Lao PDR.
Mekong River Commission. 2009. Basin Development Plan, Phase 2(BDP2): HYDROPOWER SECTOR REVIEW FOR THE JOINT BASIN
PLANNING PROCESS (Draft Report). Mekong River Commission,
Vientiane, Lao PDR.
Millennium Ecosystem Assessment. 2005. Ecosystems and Human Wellbeing: Synthesis, Island Press, Washington DC.
Nam, E. o. V., 2006. Comprehensive Development Study on Hydropower in
Se San River in Cambodia: Summary Report (Draft Volume 1). Electricityof Viet Nam, Hanoi, Vietnam.
Rogers, P., 1969. A GAME THEORY APPROACH TO PROBLEMS OF
INTERNATIONAL RIVER BASINS. Water Resources Research, 5(4),749-760.
Rogers, P., 1993. THE VALUE OF COOPERATION IN RESOLVINGINTERNATIONAL RIVER BASIN DISPUTES. Natural Resources Forum,
17(2), 117-131.
Rogers, P., and Kung, S. L., 1985. Decentralized planning for the Ganga
basin: Decomposition by river basins. Sadhana-Academy Proceedings inEngineering Sciences, 8, 123-134.
US Environmental Protection Agency (EPA). 2009. Watersheds. US
Environmental Protection Agency, <epa.gov/watershed/>.
World Bank. 2006. Mekong Water Resources Assistance Strategy(MWRAS): Options for Integrated Development and Management in the Se
Kong - Se San - Sre Pok Catchments of the Mekong in Cambodia, Lao PDR
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Cross-boundary Water Resources Adaptation: Comparing a watershed approach and a political unit approach105

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106

New Technologies for Urban Safety of Mega Cities in Asia

COMPARISON BETWEENLEED® AND CASBEE GREEN BUILDINGASSESSMENT SYSTEMPRANAB J. BARUAH, KIMIRO MEGURO
International Center for Urban Safety Engineering (ICUS)
The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 1538505{baruah,meguro}@iis.u-tokyo.ac.jp
ABSTRACT
Recently, building and construction sector is gaining increased
attention due to their potential in achieving significant energy, water andresource efficiency at minimal or no costs through integrated design
approach, which also leads to substantial green house gas reduction
towards mitigation of climate change. In order to incorporate various
sustainability elements during design, construction and operation of built
environment while improving overall building performance, green building
assessment systems are being developed around the world. In this review
paper, we give a brief overview of presently available building assessment
systems around the world before comparing two such systems, namely®
LEED(Leadership in Energy and Environmental Design) of USA and
CASBEE (Comprehensive Assessment System for Built Environment
Efficiency) of Japan. The main reason for comparing them is the differencein their assessment concept, origination country and market transformation
strategy. We carried out a descriptive comparison on their effectiveness inaddressing sustainability issues, assessment methodology, market maturity,
market transformation through leadership, awareness generation &capacity building through education, social transformation through green
building advocacy, partnership & outreach, research & development aswell as their universality & flexibility for innovation.
Building assessment systems are mainly non-profit initiatives
advocating whole building design approach and sustainable designprinciples, but their pursuance provide considerable economic benefits
along with environmental one to stakeholders, which becomes thesignificant driving factor for their adoption. Thus, these systems are incompetition with each other and their business case drives their potential
for growth, adoptability and ultimate survival of the vision/principles
behind them. Based on our comparison, we analyzed the competitive®
advantage and found that LEED
system has established a clear
competitive advantage in USA and globally over CASBEE, however,
CASBEE is the default leader in Japan in terms of adoption. It is inferred
that, overall slower adoption of CASBEE in and beyond Japan is not
because of weaker assessment effectiveness and/or result delivery potential
but because of inability to formulate a strong business case in line withpresent times.

107

October 2009, Incheon, Korea

1. INTRODUCTION
Building and construction sector has been identified as a key sector forsustainable development. The sector provides 5-10% employment innational level and generates about 5-15 % of GDP. If the energy, water andother resources consumed during construction and utilization of thebuildings in their entire lifespan is considered, built environment is
responsible for about 40% of CO2e emission, 30% of solid waste generation
and about 20% of water effluents. In terms of resources used, about 40% ofenergy, 20% of water and 10% of land-area are used by the building andconstruction sector (UNEP-SBCI, 2006). Globally, buildings use about 40%
of raw materials (3 billion tons). With business as usual, these figures areprojected to go up significantly with increasing population growth,prosperity in emerging countries and rapid urbanization. For example, China
is forecasted to add twice the amount of current office space between 2000
to 2020, with roughly 60% of Chinese population living in the city in 2030
from about 40% in 2005. In developed countries, coupled with an inefficientbuilding stock, increasing use of services and appliances, ageing population(in many countries) along with changing lifestyle leading to single-personhousehold, has increased the use of energy and resources use in buildings.
At the same time, building and construction sector is a key sector forachieving various efficiency improvements with significant green house gas(GHG) mitigation potential at minimal or negative costs (IPCC, 2007).
Sustainable building practices for efficiency improvements and GHG
abatements have not been unfamiliar to designers/architects even decades
before, however a strong business case for these sustainable designs as wellas involvement of various stakeholders and awareness at the customer level(owner and tenant) were lacking. Now, with increasing public concerns
about environment, particularly climate change with increasing energy
prices and depleting fossil fuel as well other natural resources, a green
building (GB) movement is gaining momentum. With the introduction ofgreen building assessment systems around the world, multiple stakeholders
in this complex sector with significant inertia to change is gradually
recognizing the economic potential and environmental benefits of greening
the real estate (Nelson, 2007).
In 1990, UK’s Building Research Establishment (BRE) first such building
assessment system, BREEAM (BRE Environmental Assessment Method),designed to help the UK building and construction sector incorporate
sustainability elements into their designs and construction practices. Last
decade and a half have seen development of several green building
assessment systems around the world (Baruah et al., 2008) with systems
developed in at least 20 countries and the latest one being Germany’s
DGNB released in 2009. There are hundreds of building evaluation tools
available worldwide, however, sustainable or green building assessment
systems mentioned here are those that provide a whole-building evaluation(rather than an individual design feature) incorporating an integrated andteam approach to design. So, an effective green building assessment system
incorporates vast array of best practices and techniques to also provide the108

New Technologies for Urban Safety of Mega Cities in Asiaframework and strategies to design buildings that are better than the averagestock in reducing the overall impact of the built environment on humanhealth and the natural environment by efficiently using energy, water, andother resources, in protecting occupant health and improving employee
productivity, and in reducing waste, pollution and environmental
degradation in their lifecycle. Some assessments systems also take into
account other social, structural and economic elements such as community
development, social transformation, durability and affordability. In general,
each of these tools reflects social, economic, cultural and climaticbackgrounds of the respective country.
In this paper we compare two green building assessment systems, namely
LEED® (hereafter, LEED for convenience) from US Green Building
Council (USGBC) and CASBEE from Japan GreenBuild Council (JaGBC).
Both are voluntary assessment systems. Starting with BREEAM, several
well-recognized green building assessment systems including LEED use
purely criteria based methodology assigning point values to a selected
number of parameters on a scale. On the other end, some systems use
rigorous life cycle based approach which is often difficult, laborious and atime-consuming. CASBEE takes an intermediate stance by employing ascheme that promotes life cycle assessment but with an unique methodology
to arrive at its rating criteria. In the next section, a brief overview of these
two assessment systems is given.
2. USGBC LEED & JAGBC CASBEE ASSESSMENT SYSTEM
Inspired by BREEAM of UK, in order to serve the US building community,
non-profit USBGC unveiled LEED in 1998 as a voluntary rating systemwith a market-driven strategy to accelerate adoption of green building
practices. In its website presentation, LEED claims to be a consensus-based“leading edge system for certifying the greenest performing buildings in theworld”. Originally developed for new commercial buildings (LEED-NC),
LEED has gone through major update in 2003 and now several versions
exist to serve different building types and function. The system got a major
overhaul in 2009 where additional functionalities were added with thechanges in points allocation and reweighing of some functions. In the latest
system, the entire process is expected to be flexible to adapt to changing
technology, account for regional differences and encourage innovation.
Though primarily developed for US building and construction sector, over
the years, LEED has gained world-wide popularity with the system being
adopted in countries like Canada, UK, Brazil, China, India and the Mid-East.
Supported by Ministry of Land Infrastructure and Transport (MLIT), Japan
GreenBuild Council(JaGBC)/Japan Sustainable Building Consortium(JSBC) along with subcommittees consisting of members from academia,
industry and government have developed and launched CASBEE in 2004.
Secretariat of CASBEE is administered by the Institute for Building
Environment and Energy Conservation (IBEC). According to Prof. S.

Comparison between LEED and CASBEE Green Building Assessment System

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October 2009, Incheon, Korea

Murakami, Chair of JSBC, “CASBEE creates incentives for building
owners, designers and users to develop high quality sustainable buildings.
The system meets both political requirements and market needs forachieving a sustainable society.” The latest version of CASBEE is released
in 2008. The system has been increasingly adopted by industry in Japan andseveral regional governments have made it mandatory reporting of
CASBEE ranking for new buildings.
3. COMPARISON BETWEEN LEED AND CASBEE
Table 1, 2 and 3 give the comparison between LEED and CASBEE. Please
note that lists are non-exhaustive and the comparison is based on available
information and technical manuals of the two systems. Major sources
includes, CASBEE (2009), CASBEE NCe (2008), Fowler et al. (2006),
LEED Manual (2009), Saunders (2008) and USGBC (2009).
Table 1: General Comparison: LEED vs. CASBEELEEDCASBEE

Start year

1998

2001

Developer

USGBC in a consensus process with nonprofit organizations, government
agencies, architects, engineers,developers, builders, productmanufacturers and other industry leaders

Joint industry / government /academic project. Support from
MLIT, developed by JaGBC/JSBC(secretariat by IBEC) andsubcommittees

Project
registered
Project
certified

24,679 commercial projects, June 2009
(about 5 billion square feet)
3,111 commercial projects, June 2009(floor space: 385 mil sq.ft.)

Membernumber & type

> 20,000 paying members, July 2009
Builders, Developers, Architecture firms,
NGOs, Municipalities, Universities,
Product manufacturers

Unknown, webpages (CASBEE &IBEC) do not provide information

Assessors

LEED Professional (LEED AP & GA) :131,700 (as of June 30, 2009)

3,885 (as of October 2008)

Assessor
countriesat >40 countries

Japan

Internationalpresence

Projects in 103 countries(25% of total floor space, 9% of projects)

Unknown

International
adaptation(versatility)

LEED Canada, LEED India(LEED Brazil & LEED Italia in
discussion phase)

Use in local
governments-Boston, Massachusettes and Washington
DC (from 2012) requires LEED
certifications for buildings > 50,000 sq.ft.
-Babylon, NY: permits only to buildings>4,000 sq.ft. with a LEED checklist-Arlington, Virginia requires site plansapplications with LEED score card and
LEED assessors in project

Unknown
80 (as of August 14, 2009)

Concept of CASBEE incorporated
in GOBAS, the Green Building
standard of Beijing Olympics(2005) and National Green
Building Standard of China (2006)
15 local governments in Japanrequire mandatory submission of
CASBEE assessment of theirbuildings(Total submissions 3,664 by 2008)

Table 1 continues to next page..

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New Technologies for Urban Safety of Mega Cities in Asia

..Table 1 continued from previous page
Incentive
programs
using thesystem-Chicago: Expedited permitting for LEED
certified-San Francisco: Priority permitting for
LEED Gold certified-Arlington, Virginia: Graded density
bonuses for LEED certified-Seattle: Greater height to floor spacearea for certain LEED certified

Some cities provide incentives.
-City of Osaka subsidizes
residential buildings with a A-rank-City of Nagoya has gradedsubsidy for residential buildings
based on CASBEE ranking-Financial sectors, such as banks,
are offering better interest rates tohigh ranked CASBEE houses

Revisions, last
updateWhen needed
April 2009 (major update)

Periodic, September 2008

Alliance withotherorganizations-BRE (UK), Green star (Australia)
Objective: Develop common CO2 metrics-Canada GBC, India GBC, GBC Italia,
GBC Brazil; Objective: LEED adaptation-Clinton Climate Initiative
Objective: Develop 16 large-scale urban
projects in 10 countries-SB Alliance: CSBT (France,
initiator), BRE (UK), DGNB
(Germany)
Objective: R&D co-ordination andsharing, shared use, promotion

Visiting
delegation,internshipprogramCommunication &Transparency

Open
Resources

WebpagestatusPromotion
Language
Information
channelKnown Cost
premium &payback
periodVisiting delegations comprising students,
building professionals, government
officials, and market analysts from China,
Russia, Japan, the Nordics, UK andAustralia.
Financial statements online and open,
tools and manuals available on purchase,
assessment process known, appeals
possible, organizational structuretransparent, prompt e-mail enquiry
service, Credit Interpretation Request(CIR) possible with fee-USGBC homepage: Research
publications, project case studies, GB
links, research fund proposals, general
presentation, government resources,
resources for K12 students, commercial
real estate resources, LEED
manuals(purchase) & CIRs (membershipneeded), links to chapter resources-GBCI: Credentialing resources,
certification resources, data graphs
Up-to-date with links and resources
Three main webpage (USGBC, GBCI,GreenBuild365), easy to navigate
USGBC Chapters, GreenBuild365,
USGBC website
EnglishUnknown

Tools and manuals available free,assessment process known,
organizational structure somewhat
known

CASBEE homepage, certified
project database

Up-to-date with latest tools,
Japanese page more recent and upto-date
CASBEE webpage
Japanese and English (partial)

E-mail and USGBC chapters

E-mail & telephone

Cost-premium: Vary with studies -->minimal to non-existent to an average of
2% (0.66% for LEED-certified to 6.5%
for LEED-Platinum); 3-6 years payback
period for existing buildings

No known studies

Table 1 continues to next page..

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October 2009, Incheon, Korea..Table 1 continued from previous page
-Membership: Quadrupled since 2000
-Every business day, $464 mil registeredwith LEED-Compound annual growth rate: 86%(2002-2007)-Assessors: 2700-->3885(from Aug. to Oct. 2008)-Certified Buildings: 34-->80(from Aug. 2008 to Aug. 2009)(>100% growth)-Mandatory submission by local
govt.: 2479 --> 3664
(from March to year end 2008)

Growthforecast-Overall green building market in USA to
double to $96-140 billion

Unavailable

Google hits

6,210,000 on 11 August 2009

60,000 on 11 August 2009

Growth rate

3.1 General comparison
Looking at the general comparison in Table 1, it is evident that both
systems have grown over the years due to the increasing demand ofsustainable housing around the world. LEED is gaining tremendous
popularity and growth when compared with CASBEE. Google popularity of
LEED is more than 100 times of its peer. This is because while its main
focus is on the domestic US market, USGBC is being increasingly adopted
internationally for its transparent, market-based and internet-based approach.
Over the years, it has evolved itself into three focus-based entities; Green
Building Certification Institute (GBCI) to focus on certification andcredentials, GreenBuild360 for education and outreach and USGBC for
administration, strategy and system formulation. When compared with
CASBEE, its accomplishment in advancing sustainability in the building
sector also matches its popularity. With project in more than 100 countries,
it has certified more than 3000 projects as of June 2009 compared to
CASBEE’s 80, and with a huge pool registered project in the pipeline(>24,000). It has more assessors (about 121,000 presently) than probably
assessors of all major GB assessment systems combined. LEED assessors
comprise of not only engineers or architects, but also environmentalists,
lawyers, students, product manufacturers, government officials, insurance
agents etc, or simply anyone who is interested in advancing/proving theircredentials in sustainability. Whereas, CASBEE has restricted theireligibility criteria for assessors examination to only first class Japanesearchitects. In case of CASBEE, local governments have been most active to
adopt it under the nation’s Environment Preservation Act. CASBEE is now
being adopted as a mandatory reporting standard by 15 local governments
across Japan. However, reporting does not make certification mandatory
here. In coming years, LEED may also see an upsurge as a mandatory
system by local governments since a large number of USGBC’s more than
20,000 members are now local governments. In case of CASBEE, though
the Beijing Olympic’s GoBAS system was based primarily on it, its
international presence and activities have been limited compared to LEED.
3.2 Assessment System Comparison
LEED is a point based system with 4 ratings (Certified, Silver, Gold,112

New Technologies for Urban Safety of Mega Cities in Asia

Table 2: Assessment System Comparison: LEED vs. CASBEELEEDCASBEE

Credit elements

Sustainable Sites
Water Efficiency
Energy and Atmosphere
Materials and Resources
Indoor Environmental Quality
Awareness and Education
Location and Linkages
Neighborhood Pattern and Design
Green Infrastructure and Building
Innovation in Design
Regional Priority

Versions-LEED for New Construction(includes major renovation)-LEED for Existing Buildings-LEED for Commercial Interiors-LEED for Core and Shell-LEED for Homes-LEED for Neighborhood
Development-LEED for Schools LEED for Retail

Sustainability
issuesaddressed

Global warming mitigation, Resource
efficiency, Biodiversity conservation,
Pollution prevention, Community
development, Contribution to regional
economy & community, Equity

Global warming mitigation,
Resource efficiency, Biodiversity
conservation, Pollution prevention,
Durability, Disaster risk reduction

Scoringsystem- Point based with pre-requisites- Static set of equal-weight credits canbe reweighted using a scenario tool
and/or to address regional priority- better performance more points-Eco-efficiency based BEE concept-complex weighted points-high Q & Low L, high BEE

Info gathering/paperwork

Design/project team or Assessor

Design/ project team

Assessment &certification
body

Tools andManuals-Assessor participates through designand construction process to achieve
points and puts in the paperwork to
GBCI for certification-GBCI certifies based on submitted
evidence, random audits done
-Manual can be purchased online-Online checklists, scorecard andrelevant document submission uponregistration of project

Environmental Quality (Q)Q1: Indoor Environment
Q2: Quality of Service
Q3: Outdoor Site Environment
Environmental Load (L)L1: Energy
L2: Resources & Materials
L3: Off-site environment----------------------Building Environmental Efficiency,
BEE = Q/L
Basic Tools:-CASBEE for Pre-design-CASBEE for New Construction-CASBEE for Existing Building-CASBEE for Renovation
Extended Tools:-CASBEE for temporary
construction-CASBEE [local] (e.g. Nagoya)-CASBEE for Urban Development-CASBEE for Heat Island-CASBEE for Detached House-CASBEE Urban Design+Buildings-Self certification-Third party verification is possible-Manuals can be downloaded-Excel tools/scorecard can be
downloaded

Language

English-Tools in Japanese and English-Manual in Japanese, English,
Korean and Chinese

Registration
cost$450 (members) - $600

$0Certification
cost-$1,250-$22,500 (increase from 2010)-Additional fee for CIRs and appeals-Expedited review: additional $10,000$3,570-4,500

Table 2 continues to next page..

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October 2009, Incheon, Korea..Table 2 continued from previous page
Tools and
Project tools free with registration,
manuals cost
manuals $175

Free

Resultcommunication

100 points, additional 6 in Innovationin Design and 4 in Regional Priority- Certified : 40-49- Silver : 50-59- Gold: 60-79- Platinum: > 80

Radar chart, histograms, numericalvalues and BEE
C : BEE 0-0.49
B- : BEE 0.5-0.99
B+ : BEE 1.0-1.49
A : BEE 1.5-2.99
S : BEE 0-0.49

Result productAward Letter, Certificate, PlaqueCertificate and published in webpage

Availability of
implementation
strategies

Strategies available in the manual,credit interpretation requests, projectcase studies

Strategies available in manual,project case studies

Education

Dedicated education wing,GreenBuild365. It organizes seminars,
conferences and provides year-roundgreen building related courses onsite
and online. Resources for K-12
students available

CASBEE has been used in educationin universities and private sector

R&D$2 million for GB research grantUnknown

Benchmarking

Yes

Yes

Checklist

Yes

Scorecard available

Type

OnlineOn-line Excel spreadsheet

At what stage

Design Review and Construction
Review

Preliminary design, execution designand completion

Third party
evaluation

Yes

Available

Result delivery
potential(Various
improvements )-Credits for innovation in design-Designs submitted under innovationin design credit is open for members
and registered project-CIRs open to members and projects-R & D for innovative technologies-Mandatory commissioning
prerequisites and enhanced
commissioning points-Energy and water usage data to besubmitted to USGBC annually-Existing building recertified in a
two-year cycle-On average LEED buildings are 2530% more efficient than non-LEED(Platinum and Gold: >45% efficient)-Studies available on improvements

Credit related
design enquiry

CIR (paid enquiry), leeduser.com tonavigate the latest rating system

Scope forinnovation

Assessment
verification

Flexible system that facilitates
innovation

Building certified for three years

Unavailable

Unknown

Platinum) based on total number of points achieved. It has a static set of
credits with equal weights which can be re-weighted using a credit
weighting tool with selectable scenarios. Total operational GHG emission
for the chosen scenario can be calculated. CASBEE uses a complex
calculation methodology to calculate an index called Building

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Environmental Efficiency (BEE). BEE is based on the eco-efficiency
concept by WBCSD and OECD. Weights, decided by questionnaire surveyof building practitioners and researchers, are applied to each category andsubcategories to derive environmental quality and performance andenvironmental loadings. However, unlike LEED, there is very little
information on how the credits are actually assessed, other than theperformance level required. In that sense, inconsistencies may occur andthey may be interpreted in different ways. In CASBEE, credits can beearned for ease of renewal or earthquake resistance, not available in LEED,
which are useful in an earthquake prone country like Japan. Also, credits
such as humidity control or flexibility for storey height are not available in
LEED. CASBEE also approximately calculates life cycle CO2 from thebuilding project. On the other hand, LEED has points, not seen in CASBEE,
to encourage regional use of resources and to encourage compact city andmass transportation.
However, it would be difficult to compare the systems directly
because of their difference in approach to calculate ratings. Especially, incase of CASBEE, effect/value of addressing individual issues ormodifications in deign can not be worked out until the final BEE value iscalculated. This also reduces the value of CASBEE as a design tool
(Saunders, 2008). However, CASBEE’s BEE approach can provide tradeoff between environmental loading and quality of space provided. Also,
since its metrics can be interpreted in different ways, there is more
flexibility and scope for more innovative designs to be incorporated. This,on the other hand, provides loopholes for proving effectiveness of ainefficient design. Most important of all, while both system addresses the
major issues of building environmental issues, as a system LEED provides astronger basis for whole building design with clearly stated intent,
requirement and strategies for each credit and explaining synergies withother credits to better pursue whole building design. The latest LEED V3
also provides points for integrating sustainability features with education
program in case of school projects.
3.3 Assessor System Comparison
Assessors assess and/or help design the buildings to be certified under aGB system. At the same time, an assessor indirectly promotes and spreads
the principles of the system he is accredited to assess. It is evident that,
LEED is taking a more active role in spreading the green building
movement among all stakeholders by taking a more open stance to its
assessor certification program. Apart from engineers and architects, this has
generated interests also among builders and developers to productmanufacturers, lawyers, insurance providers etc., to serve and advance thegreen building market and movement effectively. Since building assessment
systems are ideal actionable frameworks to pursue sustainability with abusiness case, understanding them also provides excellent education for ashift towards sustainability thinking. In other words, with too few
sustainability education and certifications available, passing the assessor
examination adds to one’s sustainability credentials.

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October 2009, Incheon, Korea

Table 3: Assessor System Comparison: LEED vs. CASBEELEEDCASBEE

Assessortraining-Non-mandatory; available from
USGBC, USGBC Chapters, third party
training providers recognized by
GreenBuild365 and other private
providers (range from $99 USD online
to > ~$1,500 USD)

-Mandatory from JSBC
-Held at 9 major cities across Japan
once in a year
-In Japanese only, 10,000 yen

Criteria for
Accredited
Assessor-Before June 2009: Pass exams only
-From August 2009: Pass a two-partexams; GB experience and continuing
education required(Those passing before June 2009 need
proof by 2011)

Designated JSBC training +Japanese first class Architect
license + pass exams

Certification
agencyGBCIIBEC and four other bodies.

Assessor
Examination-Held at all major cities of USA and theworld, all continents, year round-Detailed FAQ at GBCI homepage-Student pricing, special requirements(handicaps etc.) available-2 parts, total 4 hours, computer-based
200 multiple choice questions-Pass score: 85%, Pass rate: ~ 25-30%-$100 application fee, $450 exams fee,
online reservation, free certificate-Immediate result and name listing in
GBCI webpage-Held once in a year at 9 major cities
around Japan-Information in Japanese in
CASBEE homepage-40 multiple choice questions,
2 hours-Pass score: 77-80%,
Pass rate :~70-90%-15,000 yen exam fee,
10,000 yen certification fee-Reserve by fax and money transfer-Result published in webpage, excel
file of assessor list in IBEC webpage

Assessor
continuing
education

Credential Maintenance Program
through GBCI and GreenBuild365

No such program

Assessorpoints

Project receives points for having active
accredited assessors in project team

No points for having accredited
assessor in the teamWith a transparent, flexible and global assessor education and assessor
examination system, LEED is effectively spreading its vision, principles andcreating interests also in other sectors in pursuing sustainability with abusiness case. CASBEE accredited assessor system is only open to firstclass Japanese architects and having the examination in Japanese and onlyin Japan makes it exclusively a national system. Training for becoming a
CASBEE assessor is exclusively provided by JSBC whereas for LEED, it
has a dedicated training provider (GreenBuild365.com) which alsoorganizes seminars, conferences and provides substantial amount of its
training online to reach broader audience worldwide. Moreover, regional
chapters of LEED and third party private providers are also allowed toprovide training. To address the lack of experience and proper backgroundin many LEED assessors, new criteria is introduced in LEED V3 with a twotier system with mandatory experience in GB projects along with continuing
education (but not professional background).

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4. COMPETITIVE ADVANTAGE
Building assessment systems are primarily non-profit initiatives with a goal
to provide actionable framework to the building and construction industry toaddress sustainability issues such as elimination of building construction
and operations’ contribution to climate change and natural resource
depletion and thereby serve as catalyst for active participation by the sector
towards achieving sustainable cities and communities. While their primary
goal is same and is of global interest, their acceptability within the sector
depends heavily on their ability to show and prove the business case behindadoption of their proposed framework and their involvement with all
stakeholders in the building sector and society as a whole. Large scale
adoption through market transformation is the key to the advancement andsurvival of their vision. Since pursuing sustainability with an integrated
whole building design approach increases the value of a property throughdecreased operating expenses, decreased environmental risks, increased
reputation through increased environmental credentials, increased wellbeing such as productivity and health of occupants (Ries et al., 2009), thesesystems are increasingly becoming key marketing and profit-generation
tools for the industry. And in a globalized world, owners and builders alikenow prefer to adopt systems that have better reputation and are effective,
transparent, innovative and are adopted by their peers or competitors. In thatsense, in the business sphere, these systems are in competition with eachother and the advancement and survival or their vision and mission depends
on their competitiveness in the long run.
Primary factors for competitive advantage are innovation, reputation andrelationships. There are not many studies to compare the performance ofboth LEED and CASBEE on a same building. Also, since two systems aredesigned mainly for climatic and other regional conditions of theirrespective country, comparing them directly would not give any conclusive
result on which is better overall. However, there are more studies on LEEDon their effectiveness in delivering results (with hard numbers) than
CASBEE. In leadership and market transformation, both are at the forefront
in their country of origin. However, LEED has gone beyond USA anddeveloped a worldwide reputation and awareness about green buildings withprojects in numerous countries. CASBEE is clearly the winner in Japan withJapanese corporations adopting it as the default standard. Also, it has been
adopted by the local governments as a mandatory system. Without anotherassessment system available in Japanese language, probably there was also
no alternative for these local governments. However, the system is muchless transparent and less open compared to LEED. While LEED is taking aprofessional market-based approach everything from system development,
marketing, outreach, education and networking, CASBEE is taking a rather
voluntary and conventional approach in its expansion. In terms of cost of
pursuing certification, CASBEE is much cheaper to pursue. Moreover,concept of CASBEE system has been able to shift from single buildings toregional development and sustainable city with its array of tools. However,in an international arena and from a business perspective, apart fromenvironmental and other tangible benefits from pursuing an assessment

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October 2009, Incheon, Korea

system, LEED would clearly add more value to a project through its
burgeoning reputation itself.
5. CONCLUSION
With increasing interest in sustainability, a green building movement istaking place around the world. Green building assessment systems havebeen instrumental in generating interests in the building and construction
sector to pursue sustainability with a business case. We carried out adescriptive comparison of two major assessment systems, LEED and
CASBEE. Due to their difference in methodological approach and target
region for design considerations, it is difficult to compare the performanceof the assessment systems directly. However, it terms of market
transformation, green building advocacy, stakeholder involvement,
transparency & communication and adoption, LEED is found to be in aleading position. In terms of adoption, both systems are leader in theirrespective origin country, however, adoption of CASBEE is relatively
slower. Transparency and a strong strategy-driven market-based approach
are found to be the keys to rapid adoption of LEED. These, along with its
increasing partnership & outreach as well as reputation, are providing itwith a competitive advantage over CASBEE in the international arena.
REFERENCES
Baruah, P.J., Sumi, A., and Endo, T., 2008. Green Building: Current Status andProspects, In: Proc. 7th International Symposium on New Technologies for Urban
Safety of Mega Cities in Asia, Beijing, Oct 21-22, 2008, pp 767-778.
CASBEE, 2009. Comprehensive Assessment System for Built Environment
Efficiency homepage, http://www.ibec.or.jp/CASBEE/english/overviewE.htm(accessed on 10 September, 2009).
CASBEE NCe, 2008. CASBEE for New Construction Technical Manual 2008
English Edition, IBEC, 262 pp.
Fowler, K.M, and Rauch, E,M., 2006. Sustainable buildings rating systems
summary, Pacific Northwest National Laboratory, 47 pp.
IPCC, 2007. Climate Change 2007: Synthesis Report. Intergovernmental Panel on
Climate Change, 57 pp.
LEED Manual, 2009. Green Building Design and Construction, USGBC, 675 pp.
Nelson, A.J., 2007. The Greening of U.S. Investment Real Estate-Market
Fundamentals, Prospects and Opportunities, RREEF Research, 47 pp.
Ries, R., Bilec, M.M., Gokhan, N.M., Needy, K.L., 2009. The Economic Benefitsof Green Buildings: A Comprehensive Case Study, The Engineering Economist,
51(3), 259-295.
Saunders, T., 2008. A discussion document comparing international environmental
assessment methods for buildings, UK-BRE, 46 pp.
UNEP-SBCI, 2006. Sustainable Buildings & Construction Initiative, 2006
Information Note, United Nations Development Program, 12 pp.
USGBC, 2009. US Green Building Council homepage, www.usgbc.org. (accessedon 10 September, 2009).

118

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 2

IMPORTANCE OF OVERALL EVALUATIONOF CIVIL STRUCTURES TO MAINTAINSAFETYTAKETO UOMOTO
Professor Emeritus, The University of Tokyo, Tokyo, Japan
Professor, Shibaura Institute of Technology, Tokyo, Japanuomoto@sic.shibaura-it.ac.jp

ABSTRACT
Tremendous amount of structures have been built in recent years
throughout the world. These structures are important properties to thepeople as far as they are used by the people. Looking at the situation now
in our country, although the amount of the structures is tremendous, thesestructures are not always being maintained well by the public. Especially inJapan, due to natural hazards, such as earthquakes, typhoons, floods, etc.,
and the change of the economy and politics, it is difficult to maintain all thestructures in convenient state. This paper explains how we have been
looking at the problem and maintains the existing structures especiallyreinforced concrete structures. The technologies related to maintenanceare also explained in the paper.

1. INTRODUCTION
Up till now in Japan, the economic growth was rapid in the period of 1960
～ 1980. More than 100million cubic meters of concrete were used toconstruct the structures such as buildings, bridges, tunnels, dams, etc. tosupport the activities of Japanese people. As a result, these infrastructures
rapidly reached 50 years in service, and due to deterioration of the structures,
maintenance of these structures has become a major interest among theowners and the civil engineers.
On the other hands, population of Japan will reduce from now on because of
fewer babies in a family approximately 1.2 children per one family.
Although high technologies have been developed in recent years, it is surethat fewer engineers have to take care of the huge amount of structures fromnow on, which has never experienced in the past. Due to reduction in theeconomical growth, the budget for both construction and maintenance will
be reduced in the future. The maintenance of existing structures must be
done with the following conditions: 1) rapid increasing of the amount ofexisting structures reaching to the age of 50 years, 2) less amount ofengineers to maintain the structures, 3) less amount of budget can be used tomaintain the structures.

119

October 2009, Incheon, Korea

Although there are many hazards in each country, concrete structures are
expected to be safe for long period of time. Main hazards for the structuresin Japan are as follows:
1.
2.
3.
4.
5.
6.

Earthquake and volcanic action
Landslide and flood
Typhoons and strong windFire and Thunder
Accidents
Terrorism

If the structure is deteriorated before the hazards, the structure may easilycollapse andit is difficult to maintain the safety of the people. The Figure 1
shows an example of a collapsed pier during Hanshin Awaji Great
Earthquake. As shown in the photo, the pier was deteriorated to large extent
due to alkali aggregate reaction. Concrete is cracked severely and is justlike a bundle of concrete blocks.

Figure 1: Collapsed reinforced concrete pier affected by alkali aggregate
reaction
In order to keep the safety of urban area, it is important to study andinvestigate not only on hazards but also on durability aspects of existing
structures. Even a small amount of concrete spalling may cause traffic
accidents to large extent as we experienced in Sanyo-Shinkansen in 1999.
Considering these situations now, this paper explains what is happening
now in Japan and how we are dealing with the problems through researches
and engineering.

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New Technologies for Urban Safety of Mega Cities in Asia

2. GENERAL MAINTENANCE METHODS BEING USED UP TILL NOW
The maintenance of concrete structures has been done mostly by the ownersof the structures. In case of public structures, the ministries, etc. maintainthe structure after the structures are completed. For the time being, themethods for the maintenance differ according to the owners of the structures.
Although there are some differences, the main concept of the maintenancecan be summarized as follows (Uomoto and Misra, 2001):
1. Periodic inspection and evaluation of deterioration degree
2. Detailed inspection and decision making
3. Repairing and strengthening of deteriorated structures
For periodic inspections, the inspectors inspect the structures visually,sometimes with the help of binoculars and hammers, once a year or once inseveral years according to the importance and time after the structure iscompleted. The inspectors are mostly trained engineers with experiences.
The detailed inspection is done when the estimated degree of deterioration
exceeds certain limit, or when some new phenomenon is found during theperiodic inspection. The detailed inspection is done by visual inspections
with the aid of non-destructive tests or taking core samples out from theinspected structure. The purpose of the inspection is to decide the cause of
the deterioration and also to evaluate whether repair and/or strengthening isneeded or not.
To repair or strengthen the existing structures, it is important to design andselect sufficient methods and materials. The most popular repair method forcorrosion of steel bars due to carbonation is to eliminate the carbonatedconcrete and replace it by new concrete and apply coatings with and without
FRP sheets. But in case of steel corrosion due to chlorides from thesurrounding environment, the highly chloride concentrated portion of
concrete are taken out, anti-corrosive treatment is applied to the surface ofthe bar, and polymer cement mortar is generally used to repair the concrete
before coating the concrete surface.

3. CASE STUDIES OF ACTUAL EXISTING STRUCTURESIn the cities, many underground tunnels exist in the urban area. When a
new construction work is planned to build houses, facilities, etc., it iscommon to survey whether there are ny under ground structures exist or not
at the point of the new construction site. If any tunnels exist, designer must
check whether the structure may affect the tunnel or not before theconstruction occurs. But in some cases, the designer may not consider theaffect well, and it may cause effects to the existing structures.
In this chapter, two examples encountered in actual existing tunnels are
discussed. The first case is the effect of a dike of a river on the tunnel
located underneath and the second case is the effect of earth fill on thetunnel underneath. In the first case, at the design stage of the dike, it was

Importance of Overall Evaluation of Civil Structures to Maintain Safety121

October 2009, Incheon, Korea

assumed that some effect may occur on the existing tunnel andreinforcement was applied to the existing tunnel. But the inspected results
show that the effect was much larger than expected and due to the loadcracking has occurred inside the tunnel lining. In the second case, the earth
fill was only 1 to 2 meters in depth and nothing was done. Through theseinvestigations, the importance of the behavior of the tunnels constructed insoft ground or reclaimed land was clarified.
3.1 Effect on concrete tunnel under river dikes (Case 1) [1,2]3.1.1 Outline of the inspected tunnel
The figure 2 shows the relation between the tunnel being inspected and thedike above the tunnel. As shown in the figure, the tunnel is located about 10 to
20m below the dikes. The clay above and underneath the tunnel is soft comparedto sand layer, and they may settlement after the construction of dikes above.
The diameter of the tunnel is 2590mm and non-reinforced concrete lining isapplied as the secondary lining. In the normal section, steel segment withsecondary lining is applied. In the reinforced section, reinforced concrete linings
are applied inside the tunnel to increase the strength of the lining. . The thicknessof the secondary lining is 246mm, and the third or reinforced lining is 160mm tin
thickness.
(m)
Dikee

50
40

Reinforced

30

Pond

River
Sand
Clay

20
10

N=2～8

N=4～25
Sand

0
1437m

Figure 2: Location of a tunnel and dikes above the tunnel(Takeuchi and Suzuki 2007)
3.1.2 Inspected results of the tunnel
An example of the inspected result is shown in Figure 3. As shown in
the figure the cracks are observed elsewhere and the distribution is large
especially S10 to S11. Most of these cracks are vertical to the tunnel axis,
indicating that the cracks may be made by force rather than deteriorationsuch as corrosion or alkali aggregate reaction.
After the construction, the tunnel has been used for 30years and quitea large amount of settlement was observed. Every year, the height of thetunnel is measured. Figure 4 shows the height and settlement of the tunnel
just after the construction and after 30 years. As shown in the figure, thelargest settlement was observed in the span No. S 13, and another portion
was in the span No. 69. On the contrary, a large rise was observed in the
span No. 43. These figure shows that the tunnel has moved downwards insome places, but also some portion moved upwards after the construction.

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New Technologies for Urban Safety of Mega Cities in Asia

Side (left)

Center

Top

Side (right)
Span No.

S-2

S-6

補強区間
Reinforced
Section

S-10

Figure 3: Crack distribution of the tunnel from Span S2 to S14(Takeuchi and Suzuki 2007)
Comparing the measured height with the structures above, we can easilyfind that the tunnel just underneath the dikes has large amount of settlement
and the tunnel below the pond has the rise as mentioned in the Figure 5.
These results indicate that the tunnel was affected by the structures
constructed above the tunnel. When dikes are newly constructed, the tunnel
sunk down with the movement of the ground and when the load above thetunnel reduces, the tunnel rise upward as in the case of the pond excavated after.
3.1.3 Numerical analysis
To check the movement of the tunnel, FEM analysis was performed.
As shown in Figure 6, a large tensile stress occurs at the bottom of thetunnel when the Elastic modulus of the ground becomes low. On thecontrary, the stress is negligible small when the Elastic modulus of theground becomes high. These results indicate that this inspected tunnel has
suffered a lot from the load above the tunnel after the tunnel is being
constructed. As a result, the linings of the tunnel were cracked mostly by
the movement of the tunnel due to newly constructed structures just above
the tunnel.

Importance of Overall Evaluation of Civil Structures to Maintain Safety

123

100

-8
-9

Elevation from sea level (m)

50
-10
-11
0
-12
-50

-13
-14

-100
-15
-16
-150
-17
-200

-18
0

20

40

60

80

100

Total amount of Settlement (mm)October 2009, Incheon, Korea

Original
Measured
Elevation
Settlement

120

Number of Span

Height of the ground (m)

40

800
700

35

Dike

30

600
500

25

400

20

300

Height of surface (m)15Amount of
Settlement (mm)Tunnel

10

200
100
0

5

Ａ

0
0

250

-100

Reinforced
500

Amount of Settlement (mm)Figure 4: Level of the tunnel and the amount of settlement measured after
30 years (Takeuchi and Suzuki 2007)

-200
750

1000

1250

1500

Length of the tunnel(m)Figure 5: Comparison of the tunnel and the structures on the surface of theground (Takeuchi and Suzuki 2007)

E=1N/mm2

E=10N/mm2

E=100N/mm2
E=1000N/mm2
Figure 6: Tensile stress distribution of tunnel in a ground with different
elastic modulus (Takeuchi and Suzuki 2007)

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New Technologies for Urban Safety of Mega Cities in Asia

3.2 Effect on concrete tunnel in reclaimed land (Case2) [3]3.2.1 Outline of the inspected tunnel
The figure 7 shows the relation between the tunnel being inspected and theearth fill above the tunnel. As shown in the figure, the tunnel is locatedabout 3 to 10m below the ground at the time of construction and earth fill
was applied about 2 to 1 meters after 13 years. The ground above andunderneath the tunnel is soft with the N value of 1 to 20, and they may settle
after the construction. The cross section of the tunnel is shown in figure 8.
The height of the tunnel is 5.2m and the width is 3.5m. The thickness of thewall is 40cm with steel reinforcements.
8
6

Elevation
(m)
標高（ｍ）

4
2

Elevation of Tunnel

0
-2 0

100

200

300

400

500

トンネル管頂標高
建設時（1994）地盤高
Elevationof ground (1994)
2007年地盤高
Elevation of ground (2007)

-4
-6
-8

Distance fromトンネル延長（ｍ）
the Entrance of Tunnel (m)Figure 7: Elevation of the tunnel and ground surface (Kato 2008)

Figure 8: Cross section of the tunnel (unit:mm)

3.2.2 Inspected results
The arrangement of the steel reinforcements was measured by electromagnetic method. Figure 9 shows an example of the bar arrangement. It
coincides well with the designed drawings but the shear cracks wereobserved as shown in figure 10.

Importance of Overall Evaluation of Civil Structures to Maintain Safety125October 2009, Incheon, Korea

Figure 9: Measured steel bar
Arrangement

Figure 10: Crack observed on thewall

The levels of tunnel are measured every year since 2004, and the total
amount of settlement is calculated from the data. The result is shown in
Figure 11. As shown in the figure, the level of the tunnel is almost constant
except the portion between 40m to 180m from the entrance of the tunnel.
The cause of the settlement may be caused by the earth fill load appliedabove the tunnel in 2005 after the construction of the tunnel.

沈下量（ｍｍ）（mm）
Total Settlement

Settlement in 20072007年累積沈下量

2004
2004年〃

2005
2005年〃

2006
2006年〃

20
0
-20 0

100

200

300

400

500

600

-40
-60
-80
-100

Distance fromthe Entrance of Tunnel (m)トンネル延長（ｍ）

Figure 11: Total settlement of tunnel since 2004 (Kato 2008)
0

2004
2004
2005
2005
2006
2006
2007
2007
2008
2008
Anal.
解析

(mm)(mm)
Total予測沈下量
settlement

-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
40

60

80

100

120

140

160

180

(m)
Distanceトンネル延長from entrance(m)

Figure 12: Analyzed settlement of Tunnel (Kato 2008)

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New Technologies for Urban Safety of Mega Cities in Asia

3.2.3 Numerical analysis
To estimate the final settlement of the tunnel, 3-dimensional FEM
analysis was performed. The entrance (distance: 40m) is composed ofvertical shaft, and there is a pile foundation at the distance point of 180m.
In the analysis, these two points are assumed as fixed points in the verticaldirection. The elastic modulus of the soil was calculated from the measured
N-value. The load on to the surface was estimated from the specific gravityof the earth fill.
The calculated settlement is shown in Figure 12. As shown in the
figure, the calculated value coincide well with the measured settlement in
the year 2008. From the result, it can be estimated that the settlement wascaused by the earth fill mounted on the surface just above the tunnel. Fromthese two case studies, it is important to know that the tunnels in soft
foundation may be cracked due to settlement of the surrounding land. To
check the cause, periodic overall measurement of level of the structure is agood method to estimate the cause of cracks.

4. PROBLEMS IN ACTUAL EXISTING STRUCTURES
When a civil engineer is asked by the owner to check the safety of an old
existing structure, one of the largest problems is that there are neither
drawings nor construction records of the structure available. No problem
may occur in case of important facilities, which is maintained with greatcare. But in case of normal structures, the owners do not know theimportance of these documents.

7,300

85 0 65 0
D16120190

4,500

65 0
4,500

250
D25

1,000 30 0

12 023 0

21@300１

1,300

280 8@200

210

50 280 9@200

18,390CL

9,390
280 16@200280

D13
120@125
15,620120

Figure 13: Re-designed reinforced concrete pier of a bridge(Okazaki ,2005)
To deal with the problem, NDI is not enough. Fortunately, our structures
are not too old, and they are mostly designed and constructed by the method
specified by JSCE, AIJ or other associations. Considering these, the only
way is to re-design the structure again using the methodologies used at theImportance of Overall Evaluation of Civil Structures to Maintain Safety127

October 2009, Incheon, Korea

time of construction. Figure 13 shows an example of re-designed bridge
pier constructed about 35 years ago. From the figure, it is much easier for a
civil engineer to check the safety of the structure under several hazards. It
will become more important for the owners and engineers to keep these
documents throughout the service life of a structure.

Figure 14: Estimation of the movement of a steel truss bridge when amember is deteriorated (Yasuzawa 2007)
When we have to monitor existing structures by NDT, important point iswhere and how to monitor. Because the amount of fee is limited, we can
not monitor everything at all points. As mentioned in Chapter 3, it isimportant to keep the structure safe to the public. To do so, the engineers
have to estimate where and how to monitor. The figure 14 shows how thesteel bridge behaves if a member of the steel truss bridge is deteriorated.
The calculation is done by 3 dimensional analysis, checking all the members
what may happen if the member is deteriorated and can not support the load.
As can be seen from the figure, the vertical member at the point of support
is very important to maintain the bridge safe enough for the people to go
across.
Knowing the evidence, we can monitor the bridge at this point. May bestrain measurement is enough to check the safety of this bridge. Further, if
we wish to monitor the structure as a whole, several points may be enoughfor the monitoring. We can reduce the cost to maintain and monitor the
structure not to cause catastrophic failure.

5. CONCLUDING REMARKS
Engineering is not always complete, and further research works are needed.
To sustain existing structures, durability of the structure is important. One
good method is to construct durable structures, but for the existing
structures maintenance is the only way to deal with the problem. Althoughconcrete committee of JSCE has set up a good system for maintenance ofexisting concrete structures, there are still many things to be done: not only
researches but also education to the students and engineers about durability
and maintenance. I hope this paper may become a help to the concrete
engineers of the world who are trying to design, construct and maintainconcrete structures.
REFERENCES

128

New Technologies for Urban Safety of Mega Cities in Asia

Concrete Committee of JSCE, Standard Specifications for Concrete
Structures-2007 “Design”. JSCE, Tokyo.
Concrete Committee of JSCE, Standard Specifications for Concrete
Structures-2007 “Materials and Construction”. JSCE, Tokyo.
Concrete Committee of JSCE, Standard Specifications for Concrete
Structures-2007 “Maintenance”. JSCE, Tokyo.
T. Uomoto and S. Misra,. Role of Engineers to Improve Quality of Concrete
Structures. Proceedings of EASEC-8, Singapore, 2001.
S. Suzuki, K. Kinoshita and T. Uomoto: Fundamental study on crack
distribution and settlement of Shield Tunnel Lining, JSCE General Meetingof Kanto-shibu, 2008
M. Takeuchi, Y.S hirane and T. Uomoto: Fundamental study on relation
between crack and surface load on Tunnel Lining, JSCE General Meeting ofKanto-shibu, 2008
M. Kato and T. Uomoto: Fundamental study on causes of tunnel
deterioration in urban area, JSCE General Meeting of Kanto-shibu, 2009
Okazaki, S., 2005. Development of monitoring system for RC bridge basedon restoration design method. Thesis submitted to the University of Tokyo
for Master of Engineering degree.
S. Yasuzawa and T. Uomoto: Estimation of dangerous points of an existing
steel truss bridge, JSCE General Meeting of Kanto-shibu, 2008

Importance of Overall Evaluation of Civil Structures to Maintain Safety

129

NONLINEAR ANALYSIS OFSHEAR STRENGTHENING OF
REINFORCE CONCRETE COLUMNSBY USING FIBER REINFORCE POLYMERPRAGASIT JUNTANALIKIT
Sirindhorn International Institute of Technology,
Thammasat University, Pathumthani, Thailand
pj_bank2@hotmail.com
AMORN PIMANMAS
Sirindhorn International Institute of Technology,
Thammasat University, Pathumthani, Thailand
amorn@siit.tu.ac.th

ABSTRACT
Seismic assessment and retrofit of existing columns in buildings
require accurate prediction of the available deformation capacity. In last
decade, Fiber Reinforced Polymer (FRP) has been used widely to enhancestrength and deformation capacity of deficient reinforce concrete (RC)column. This paper presents a study of a RC rectangular column
strengthened by wrapping FRP sheet. An analytical model is proposed torepresent potential plastic hinge regions of RC columns under cyclicloading by fiber-section spring model. The shear transfer mechanism of thespecimen reinforced with FRP sheet was developed based on previous
proposed model, represented by one nonlinear shear spring. The proposed
analytical model is verified with the available cyclic test data of an earlier
study on five columns with and without FRP. The study shows thatconventional concrete column strengthened with FRP could be predictedwith a Fiber-section element spring model which is capable of capturing
essential features of the response such as strength degradation due to lap
splice slippage. Furthermore, it is observed that, in estimating the responseof existing deficient columns, parameters such as plastic hinge length,
concrete strength and splice length are important sources of uncertainty.
Good agreement was shown between the analytical models and theexperimental results.

1. INTRODUCTION
The aim of the seismic design of reinforced concrete (RC) column is to
avoid brittle failure modes. In terms of the strength, shear failure in column
can be avoided by making shear failure capacity exceeding maximum
flexural feasible capacity. For under-designed column with low shear131

October 2009, Incheon, Korea

strength, shear strengthening is required to increase the shear capacity.
Externally bonded FRP for increasing shear resistance has been popular
recently. The deformation capacity can also be enhanced because FRP
confinement can delay concrete crushing.
There are vast experimental works on using FRP for retrofitting substandard
columns. Experiments performed on the retrofitting substandard column
with FRP lamina demonstrated the increase in strength and deformation
capacity. The result also displays the great increase in energy dissipation of
FRP-confined column, similar to those confined with internal steels. The
external confinement of concrete using FRP is also effective in increasing
the splice strength compared with the internal confinement provided byordinary transverse steel.
It is possible to predict the behavior of RC column strengthened with FRP
lamina using the concept of fiber-discretized nonlinear frame element
together with the associated constitutive modeling of steel and concrete. The
aim of this paper is to propose an analytical model that can be simulate
gravity-designed reinforced concrete columns confined by FRP confinement
under reversed cyclic loads. The backbone shear force-shear displacement is
adopted from previous research. The general framework on nonlinear frame
element is proposed and verification with available experimental data ispresented

2. ANALYTICAL MODELINGThe cantilever column fixed at base is modeled as a nonlinear frame
element that is divided into two zones; the nonlinear zone that models theplastic hinge at the base and the elastic zone above the nonlinear zone
(Matrin 2007). This model is extended to investigate the cyclic response ofcolumn confined by FRP.
2.1 Length of Plastic hinge
In a cantilever RC column, plastic hinge forms at the section of largest
moment which is at the base of the column. The reinforcement yields in thiszone and the concrete is loaded to nonlinear range. The length of plastic
hinge is determined based on the work of Paulay and Priestley (1992) as
L p  0.08 L  0.022d b F y(1)

As mentioned, the entire column is divided to two zone; elastic andplastic zone. The plastic zone has the length determined from equation 1.
The remaining length of column is therefore governed by a linear elastic
response.

132

New Technologies for Urban Safety of Mega Cities in Asia

2.2 Elastic-frame element
The upper portion of the column is linearly elastic, thus it can bemodeled by elastic frame element. The flexural and axial stiffness used inelastic frame element can be calculated according to the recommendationsof ATC-40 (ATC,1997).
Effective Flexural Rigidity  0.7 E c I g
Effective Axial Rigidity  1.0 E c I g

2.3 Fiber discretization in the plastic zone

Steel Bar

Concrete FiberhLp(a) RC column model(b) Discrete fiber section

Figure 1: Geometry of fiber-section element
The nonlinear plastic hinge zone is to model the nonlinear flexural andshear behaviors. The nonlinear flexural response can be modeled using theconcept of fiber discretization in figure 1(a). In this concept, the crosssection is divided into several fibers; each containing concrete, steel or both
(Figure 1(b)). The fiber section adopts the assumption of “plane section
remains plane”. The concrete and steel fibers can be modeled with nonlinear
springs. If the properties of steel and concrete spring are known, it ispossible to analyze the response of the column. The constitutive models canbe modified FRP confinement. As for shear behavior, a nonlinear shear
spring is also attached at the plastic hinge. The following sections explain
the nonlinear properties of concrete and steel under the external
confinement of FRP.
2.4 Concrete spring
For the RC column section confined with transverse reinforcement,
the concept of the effectively confined concrete area proposed by Mander et.
al. (1989a) is used. The strength enhancement due to confinement isdetermined by stirrup spacing, strength of reinforcement and configuration

Nonlinear Analysis of Shear Strengthening of Reinforce concrete columns by using Fiber Reinforce Polymer 133

October 2009, Incheon, Korea

of sectional dimension. The maximum axial stress of confined concrete andthe corresponding strain can be computed as follows:f cc  Kf co


(2)

 f cc 1
 f co cc   co 1  5(3)Consider confined concrete wrapped with FRP jacket. Lam and Teng
(2003a) presented the maximum stress and maximum confinement pressure
as follows:  3.3K a f l
f ccu
2 E f nt f  fe
fl 
D


 ccu   c 1.50  12 K b


(4)
(5)
f l   fe 
f c   c (6)

The maximum compressive strain of the FRP confined concrete canbe found using equation 6 where K a and K b are the effective factor
accounting for the geometry of the section.
Roy and Sozen (1964) introduced the formula for computation theslop of descending line. The value of strain at one-half of peak concrete
stress can be calculated as follows: 50 

3  0.29 f co
145 f co  1000

(7)

2.5 Steel bar spring
The cyclic model of longitudinal reinforcement is assumed to bestraight line to represent elastic condition followed by the horizontal line
representing the yielding of reinforcing bar. The stiffness of reinforcement
is computed as total area of reinforcement As  multiplied the elastic
modulus of steel E s  and divided by plastic hinge length L p  . The yieldforce can be obtained from multiplying the yield stress of reinforcement( Fy ) with total area of reinforcement.
2.6 Lap splice spring

The stress in bar along the lap splice zone is assumed to be developed
along the development length in the plastic hinge zone. Along thedevelopment length of the spliced bar, the yielding portion of reinforcement( L y ) and the elastic portion of reinforcement ( Le ) can be computed by134

New Technologies for Urban Safety of Mega Cities in Asiaequation 8 and equation 9 respectively. The amount of slip is computed byintegration of strain along required development length ( Le  L y ) and isexpressed by Equation 10.
Le 

Ly 

fedb
4u e

(8)

 f s  f e d b



4u y

(9)



 s  0.5 Le   f e   L y   f e     f s 

(10)

The bond stress-slip relationship is proposed by Alsiwat andSaatcioglu (1992), and Lowes et al. (2003). The average elastic bond stress(u e ) is determined by substituting value of development length ( Ld )recommended by ACI318-05 into equation 8. For the average values ofbond stress in yielding portion of reinforcement (u y ) , the value of 0.4 f cas proposed by Harajli (2004) is assumed in this study.
2.7 Shear spring

The experimental and theoretical analysis was applied to develop a
simple method for calculating the shear strength of FRP confined section.
The modified shear model divides the shear capacity into three components.
The first component represents the shear transfer mechanism of concrete
denoted by Vc which depends on the magnitude of axial load, shear span toeffective depth ratio and concrete cross-section. The second component istransverse reinforcement contribution, Vs .The third component is the shear
force contribution of FRP, V f .
V n  Vc  V s(11)

Vsi  Vc  Vn  V f(12)

In order to investigate of mechanism of shear behavior, shear
resistance for RC column under monotonous increasing lateral deformation
was studied by Halili Sezen (2008). The shear model was adopted for
nonlinear shear-spring as shown figure 2. The critical points of the model
are maximum shear strength, the onset of strength degradation and the lossof axial-load carrying capacity. The formula for the maximum shear
strength Vn  is given by equation 13.
Vn  kAv f vy ds 0.5 f 
P 
c
 k
1
0.8 Ag
 a/d
 
f
0
.
5
c



(13)

Nonlinear Analysis of Shear Strengthening of Reinforce concrete columns by using Fiber Reinforce Polymer 135

October 2009, Incheon, Korea

Figure 2: Proposed shear model
The factor k is defined to be 1.0 for the displacement ductility lessthan 2, 0.7 for displacement ductility exceed 6.0, and to vary linearly forintermediate displacement ductility. For the column that fail in shear, theaverage shear strain at the maximum shear force is influenced by many
parameters such as, the axial load ratio, yield strength of reinforcement, andlongitudinal steel ratio. The value of shear strain at the maximum shear
force can be calculated from equation 14.

u 

f yl   laP5000  dAg f c 0.0004(14)

The shear strength is assumed to be constant until the onset of strength
degradation. The shear strain at the onset of strength degradation is
calculated from equation 15.
v 
f c 

 n   4  12 n  u

(15)

The last point on the shear envelope defining the axial load failure isalso considered to completely the shear model. The deformation capacity at
this point is derived from the shear friction model proposed by Elwood andMoehle (2005). The angle of the shear crack is assumed to be 65 degree.

 ALF  0.04 

1  tan 2 
L


s

tan   P
 A f d tan  
v
vy
c



(16)

Regarding the shear transfer mechanism of RC member, shear force
resisted by the FRP is assumed to follow the truss mechanism, similar totruss mechanism carried by transverse reinforcement as shown in figure 3.

136

New Technologies for Urban Safety of Mega Cities in Asia

The shear contribution of FRP can be determined using equation 17. In the
FRP-confined column, the shear strain of FRP is very small before diagonal
shear crack occurs and increases very quickly after shear cracking. However,the strain of FRP does not reach the ultimate value at the maximum shear
strength of the column, while the transverse steel was assumed to attainyielding.
Thus, in the shear model, the first straight line segment in the figure 2
can be divided into two-sub-stiffnesses: the first segment to represent theelastic shear stiffness of the RC column, and the second segment torepresent the elastic shear stiffness after shear cracking. It is noted that theshear stiffness of strengthened depends on the tensile modulus, width of
FRP reinforcement, and the thickness of the layer as shown in figure 4 (G.
Promis (2008)). However, the last two points of the shear model of FRP
confined column lacks supporting experimental evidence. As a result, thepoint at the onset of shear degradation and axial load failure are assumed tofollow equation 15 and equation 16 for unconfined section.
Vf 

A fv f fe sin   cos  d fv
Sf

A fv  2nt f w f

(17)
(18)

V
wf


Sf

d fv
V

Figure 3: Shear transfer mechanism of FRP

Figure 4: Influence of stiffness in relation to width of the band and slope

Nonlinear Analysis of Shear Strengthening of Reinforce concrete columns by using Fiber Reinforce Polymer 137

October 2009, Incheon, Korea

3. VERIFICATION OF REINFORCED COLUMNS WITH ANDWITHOUT FRP CONFINEMENT

The results of two experimental programs conducted by Lieping Ye at. al.
(2002), used for validation of the analytical model. The specimens were
tested under a single curvature set-up and assigned reverse lateraldisplacement under constant axial load. One reference specimen and one
CFRP-retrofitted specimen were analyzed using the developed models. In
strengthened specimen (CS20-1-15), the length of CFRP confinement wascovering the entire column length with partial wrapping. The column ismodeled using a fiber-section method with each fiber being ten millimeter
width. The columns section was 200mm x 200mm with round corner toavoid stress concentration in FRP sheets. Eight longitudinal reinforcing bars
with diameter of 22 mm were assigned round the section perimeter. The
transverse reinforcement hoops were 6 mm diameter with spacing of 200
mm for both specimens.
Table 1: Specimen’s Parameter
Code ofcolumnf c (MPa)a/h

CFRP sheetnCS20-0-15
CS20-1-15

48.2
48.2

2.0
2.0

20x60

0.13
0.13

Diameter(mm)
22
6

Table 2: Material Properties
TensileYield
Area
strength
strength
(mm2)
(MPa)
(MPa)
380.1
381
571
28.3
345
492

Elastic
modules2.0x1052.1x105

The experimental parameters for both specimens are listed in table 1 andtable 2. The tensile strength and elastic modules of CFRP were 3500 MPa
and 2.35x105 respectively. The comparison of cyclic responses of bothcolumns with the experimental results is presented in figure 5. It can beobserved that significant strength degradation of unstrengthened column
occurs after reaching the peak strength. For the FRP-retrofitted column, thepeak shear strength is increased and the load degradation is delayed.
The model simulations of strength and deformation at maximum load areagreeable with experimental results. The slope of descending branch on theenvelope curve also have good match between analytical and experimental results.
The developed model is also verified with the columns tested by Melanie
Marcos-Regino (1999). Three column specimens were tested under cyclic
lateral load. The specimens represent lightly transverse-reinforced RC column
with the spacing of transverse steel of 300mm. The 1350 mm-tall and 300
mm-square cross-section columns were reinforced with 20 deformed D13

138

New Technologies for Urban Safety of Mega Cities in Asia

bars. The column height-to-diameter ratio was 3.7, indicating the shear failuremode in a single curvature condition. The compressive strength of concrete
was 32.1 MPa, and the tensile strength of the longitudinal reinforcement andtransverse reinforcement was 434 MPa and 346 MPa, respectively. One
control specimen was compared with two CFRP-retrofitted specimens. The
difference was the technique of strengthening with a layer thickness of 0.11
mm. One strengthened column (SP-2) was partially wrapped transverse to thecolumn axis and the other specimen (SP-3) was diagonally wrapped from thebase as shown in figure 6. Figure 7 shows the comparison between the modeland experimental result. It is found that the response of analytical model
agreed closely with the experimental results.

(a) CS20-0-15(b) CS20-1-15
Figure 5: Comparison of test and predicted result

Specimen
CS20-0-15
CS20-1-15

Table 3 Test Result
Lateral ForceExperimental
Analysis
(kN)
(kN)
147
150
177
179

Failure
Mode
Shear
Shear

(a) SP-1(b) SP-2(c) SP-3
Figure 6: Technique of strengthening CFRP
250

160

200

200

140

150

150

100

120

100

80
60

0
-60

-40

-20

-50

0

20

40

60

Test

20

-200

0
2

4

6

8

Displacement(mm)

10

12

14

-20

0

20

16

-250
Displacement (mm)

40

60

-100

-150

Predicted
0

0
-40

-50

-100

40

-2

50

50

Load (kN)

Load (kN)

Load (kN)

100

Test
Predicted

-150

Test
Predicted-200
Displacement (mm)(a) SP-1(b) SP-2(c) SP-3
Figure 7: Comparison of test and predicted result

Nonlinear Analysis of Shear Strengthening of Reinforce concrete columns by using Fiber Reinforce Polymer 139

October 2009, Incheon, Korea

4. CONCLUSIONSThis study was carried out to develop a model to analyze RC column
confined by FRP under cyclic lateral displacement. The columns are thosethat are susceptible to shear failure. The analytical model is described to be
based on the fiber-section technique. The nonlinear models for concrete andsteel spring incorporating the effect of FRP confinement are described. The
nonlinear shear model taking into account the effect of FRP confinement isalso proposed based on the previous model developed for unconfinedcolumn. The developed models have been applied to analyze columns tested
in the past. A good agreement is found for both experimental series. The
nonlinear shear model should be enhanced especially for the point ofstrength degradation and the point of axial load failure for the section that isconfined by FRP.

NOTATION

The following symbols are used in this paper:
Av = area of transverse reinforcement (mm2)
A fv = area of FRP external reinforcement (mm2) co = compressive strain of unconfined concrete (mm/mm)

 c = maximum strain of unconfined concrete (mm/mm)
 cc =compressive strain of confined concrete (mm/mm)

 fe = effective strain level in FRP reinforcement attained at failure(mm/mm) ccu =compressive strain of FRP-confined (mm/mm)

f co =compressive strength of unconfined concrete (MPa)f l = maximum confining pressure (MPa)f e = maximum stress of reinforcement in elastic portion (MPa)f fe = effective stress in the FRP attained at section failure (MPa)f vy = yield strength of transverse reinforcement (MPa)f s = maximum stress of reinforcement in yielding portion (MPa)f cc =compressive strength of confined concrete (MPa)f ccu=compressive strength of FRP-confined (MPa)K = effective confinement coefficientLy= development length required for yielded portion of reinforcement(mm)L= length of column (mm)Le = elastic portion of reinforcement (mm)140

New Technologies for Urban Safety of Mega Cities in Asia

Lp

= plastic hinge length (mm)u e = average elastic bond stress (MPa)uy= average plastic bond stress (MPa)d b = diameter of longitudinal reinforcement (MPa)Fy= yield strength of longitudinal reinforcement (MPa)E c = elastic modulus of concrete

E s = elastic modulus of reinforcement
E f = tensile modulus of elasticity of FRP
Ig= moment of inertia of the gross section
Ag = area of the gross section (mm2)s = spacing of transverse reinforcement (mm)d = effective depth (mm)d fv = effective depth of FRP shear reinforcement (mm)a = shear span (mm)k = degarrding coefficient
P = axial force (N) l = longitudinal steel ratio

REFFERENCE

Richard D. Lacobucci, Shamin A. Sheikh, and Oguzhan Bayrak, Retrofit ofSquare Concrete Columns with Carbon Fiber-Reinforced Polymer for
Seismic Resistance, ACI Structural Journal, V.100, No.6, Nov-Dec 2003.
Mohamed H. Harajli and Ahmad A. Rteil, Effect of Confinement Using
Fiber-Reinforced Polymer of Fiber-Reinforced Concrete on Seismic
Performance of Gravity Load-Designed Columns, ACI Structural Journal,
V.101, No.1, Jan-Feb 2004.
Muhammad S. Memon and Shamin A. Sheikh, Seismic Resistance ofSquare Concrete Columns Retrofitted with Glass Fiber-Reinforced Polymer,
ACI Structural Journal, V.102, No.5, Sep-Oct 2005.
S. Matthys, H. Toutanji, K. Audenaert and L. Taerwe, Axial Load Behaviorof Large-Scale Columns Confined with Fiber-Reinforced Polymer
Composites, ACI Structural Journal, V.102, No.2, Mar-Apr 2005.
Kent A. Harries, James R. Ricles, Stephen Pessiki, and Richard Sause,
Seismic Retrofit of Lap Splices in Nonductile Square Columns Using
Carbon Fiber-Reinforced Jackets, ACI Structural Journal, V.103, No.6,
Nov-Dec 2006.
Melanie Marcos-Regino (1999), Shear strength enhancement of reinforced
concrete bridge piers by wrapping of fiber reinforced plastic sheet, M Eng
Thesis, Saitama University, Japan.
ACI 440 American Concrete Institute committee 440, (2008) Guide for thedesign and construction of externally bonded FRP systems for strengthening

Nonlinear Analysis of Shear Strengthening of Reinforce concrete columns by using Fiber Reinforce Polymer 141

October 2009, Incheon, Korea

concrete structures. American Concrete Institute committee 440,Farmington
Hills, Michigan.
G. Promis, E. Ferrier, P. Hamelin, Effect of external FRP retrofitting on
reinforced concrete short columns for seismic strengthening, Composite
Structures 88 (2009), 367-379.

142

New Technologies for Urban Safety of Mega Cities in Asia

EXAMINATION CONCERNING
THE ACCEPTANCE INSPECTION
FOR QUALITY ASSURANCEOF STRUCTURAL CONCRETE
SHOTA MIZUKAMI
Department of Civil Engineering, Shibaura Institute of technology
m509091@sic.shibaura-it.ac.jp
TSUGIO NISHIMURA
Institute of Industrial Science, University of Tokyotsugio@iis.u-tokyo.ac.jp
YOSHITAKA KATO
ICUS, Institute of Industrial Science, University of Tokyo
katoyosh@iis.u-tokyo.ac.jp
FUTOSHI KATSUKI
Shibaura Institute of technology
katuki@sic.shibaura-it.ac.jp

ABSTRACTThe construction process greatly influences the quality of structuralconcrete, so it is necessary to improve the inspection method of the process.
In particular, the acceptance inspection of the current state does not
appropriately consider durability, so this research aims at the establishmentof an appropriate concrete acceptance inspection for quality assurance
considering durability, and examined stiffening behavior and flesh
properties. As a result, it was found that the influence of environmental
condition on compressive strength and air permeability is different, and it
was clarified that it is difficult to use compressive strength as arepresentative parameter for durability. By changing the fineness modulus,
sand-aggregate ratio, and unit water content in the tamping test, thesegregation resistance was determined by calculation of flow coefficient,and the usefulness of the tamping test became clear. In the future, it will benecessary to relate this result with other viscous measurement technique.

1. INTRODUCTION
In recent years, the importance of quality control and inspection
systems has increased due to the large amount of careless construction
works done by low bids. Since the construction process greatly influences
the quality of structural concrete, it has become necessary to introduce theexecution process. To improve the inspection system, the influence on
durability factors should be controlled and the results should be applied
immediately.

143

October 2009, Incheon, Korea

Based on those current conditions, this research aims at theestablishment of a quality inspection system for structural concrete. For thebasic examination, fundamental tests were performed on the acceptanceinspection of concrete. Compressive strength is one acceptance inspection
criteria, and is used as a substitute index to evaluate durability. However,when the curing method is changed, resistance to mass transfer in coverconcrete changes greatly, but this is difficult to confirm using only thecompressive strength test, so the influence of curing method was measured
and the air permeability of the concrete compared with the compressive
strength. Next, testing of fresh property was conducted and the workability
estimated by consistency and segregation resistance. Slump is highly
influenced by the yield stress of the sample, so it is difficult to evaluate
segregation resistance by slump test. Therefore, the tamping test andcylinder penetration test were conducted to evaluate the materials’
segregation resistance and water content per unit volume.

2. EXPERIMENTAL OUTLINE
2.1 Air permeability test
Concrete mix proportions are shown in Table 1. Specimens were castin summer (July), autumn (September), and winter (December) and cured
outside to consider the influence of the seasonal climate conditions; these
conditions in Otemachi, Tokyo, are shown in Table 2. Materials for mixing
were prepared and stored at 20ºC for 24 hours before casting. The
specimens were cylinders φ 100×200mm.
Table 1: Mix proportions (air permeability and compressive
strength test)
3
Slag
W/C s/aCementsubstitution(%) (%)
rate(%)
OPC
BB

40
50
60
40
50
60

41
43
45
41
43
45

－
－
－
45
45
45

Amount of unit(kg/m )

W

C

BS

S

G

179
171
171
179
171
171

448
342
285
246
188
157

－
－
－
202
154
128

667
746
804
661
742
799

986
1015
1007
977
1010
1002

AE

AE waterreducing
agent

C*0.01%

C*0.25%(C+BS)*
0.01%(C+BS)*
0.25%

Table 2: Climate condition during curing period (OPC)
Average temperature : ℃
SummerAutumnWinterAverage
28.5
22.2
9.1
Average humidity : %SummerAutumnWinterAverage
70.0
69.8
48.3

144

Precipitation in total : mm
SummerAutumnWinter
Total
168.5
247.0
39.5
daylight hours : h/day
SummerAutumnWinterAverage
5.5
3.3
7.1

New Technologies for Urban Safety of Mega Cities in Asia

Three curing methods were used, as shown in Figure 1, and the total
curing period was 28 days for all three conditions. The period of wet curing
was decided by the average temperature during the period, per the Japan
standard specifications for concrete structures (JSCE, 2007). After curing, a
40mm section was cut from the center of the cylinder with a wet processcutter and spin-dried with a furnace dryer.
28daysWater-curing

Wet-curing

Air-curing

Air-curing

Figure 1: Curing method environmental conditions
These specimens were then fitted in a rubber cylinder and set up in acell of the air permeability device (Fig. 2). Compressed air is injected into acell, and once the air flow reaches steady state, the volume can be measured
by the amount of water displaced, and the air permeability coefficient can becalculated by equation (1) from this value and the loading conditions (Ujiie
and Nagataki, 1988).

K=

2rLP2 Q
2

2

A( P1 − P2 )(1)
Where, K is coefficient of air permeability (m/s), P1 is loadingpressure (N/m2), P2 is atmospheric pressure (N/m2), L is the thickness of thespecimen (m), Q is quantity of air penetrating (m3/s), A is surface area ofspecimen (m2), r is unit volume mass of the air (=11.81(N/m3)).
Regulator

Data logger(Loading pressure
monitoring)Compressed
air cylinder
Water
displacement
methodFigure 2: Schematic of air permeability test machine

Examination concerning the acceptance inspection for quality assurance of structural concrete

145

October 2009, Incheon, Korea

Compressive strength test specimens were prepared under the same
conditions as air permeability specimens in order to compare the effect of
curing environment on air permeability and compressive strength. Results
for are the average of three specimens.
2.2 Tamping test
The tamping test is a test method used to evaluate the segregation
resistance and consistency of concrete (Ishii et al., 2008). Measurement
items and methods are shown in Table 3 and Figure 3.
Table 3: Measurement items and methods for tamping test
Measurement item

MethodSlump flow

When slump cone is raised and slump flow is 250, 300,
350, 400, and 450mm, the following items are measured.

Slump

At the time of each slump flow value.

Upper circle
Number of tampingtimes

At the time of each slump flow value;
circular presence and diameter are examined.
A wooden stick of mass 1.2kg is dropped from 50cm highsequentially on the four corners of the slump board.
The necessary tongue Ping number of times to reach eachslump flow is recorded.

Figure 3: Schematic view of the tamping test
Mix proportions are shown in Table 4. Fineness modulus was selected
as one experimental parameter to evaluate segregation resistance. As thefineness modulus becomes larger, segregation resistance increases but
consistency decreases. Two sizes of coarse aggregate, "5-13mm" and "1020mm", were used and three kinds of fineness modulus were set bychanging their mixture ratio. Similarly, sand percentage (s/a) was used by"40%", "45%", and"50%" to understand its effect of viscosity. Finally, threemix proportions with varying water content per unit volume were also tested.
The Ministry of Land, Infrastructure, Transport and Tourism in Japan(MLIT) specifies that water content per unit volume should fall within therange of ±15kg/m3. Therefore, the water content was varied ±15kg/m3 totest this effect.

146

New Technologies for Urban Safety of Mega Cities in Asia

Table 4: Mix proportions (for tamping test)
Amount of unit(kg/m3)
Change item

Water content
per unit volume
Fineness modulus

Sand percentage

s/a
(%)

W

C

S

G

45
45
45
45
45
45
40
45
50

156
171
186
171
171
171
171
171
171

260
285
310
285
285
285
285
285
285

827
804
763
804
804
804
714
804
892

1046
1007
964
1007
1007
1007
1099
1007
916

G:5-13mm G:10-20mm
504
504
504
806
504
201
504
504
504

504
504
504
201
504
806
504
504
504

AE

AE waterreducing
agent

C*0.01% C*0.25%

Slump
(cm)
8.5
10.0
17.5
11.5
10.0
9.0
9.5
8.5
7.5

3. RESULTS AND DISCUSSION
3.1 Air permeability results
The results of the compressive strength and air permeability tests when
expressed as the change in relation to water curing are shown on the Table 5
for all test cases. For both cement types, the compressive strength tends todecrease as water-cement ratio increases. In addition, the results decreased
in order "water"→"wet+air "→"air". Air permeability tends to increase
under the conditions given above. This shows that there is an inverse
relationship between strength and air permeability. However, in comparison
with the rate of change of compressive strength, the rate of change of air
permeability is very high.
Table 5: Results of the compressive strength and air permeability tests
Kind of tests
Water-cement ratio ・ Seasons Cement
W/C=40%・Summer
W/C=50%・Summer
W/C=60%・Summer
W/C=40%・Autumn
OPC
W/C=50%・Autumn
W/C=60%・Autumn
W/C=40%・Winter
W/C=50%・Winter
W/C=60%・Winter
W/C=40%・Summer
W/C=50%・Summer
W/C=60%・Summer
W/C=40%・Autumn
BB
W/C=50%・Autumn
W/C=60%・Autumn
W/C=40%・Winter
W/C=50%・Winter
W/C=60%・WinterCompressive strength
Water Wet+Air
Air
1
0.92
0.80
1
0.99
0.81
1
0.98
0.77
1
0.95
0.95
1
1.01
0.94
1
1.04
0.93
1
0.90
0.83
1
0.88
0.82
1
1.00
0.89
1
0.89
0.74
1
0.87
0.68
1
0.89
0.61
1
0.90
0.84
1
0.92
0.86
1
0.92
0.85
1
0.76
0.72
1
0.78
0.70
1
0.73
0.65

Coefficient of air permeability
Water Wet+Air
Air
1
2.60
2.80
1
3.09
5.81
1
1.75
6.85
1
1.73
1.46
1
2.21
1.92
1
1.48
2.28
1
3.59
3.08
1
4.19
4.21
1
2.66
5.06
1
2.32
2.34
1
1.74
2.76
1
1.59
3.02
1
2.01
1.83
1
1.57
1.35
1
1.54
1.74
1
3.56
2.47
1
1.59
3.38
1
1.47
4.81

A conceptual diagram of the general tendencies of the test results,
when expressed as the change in relation to water curing, is shown in Figure
4. First, the "quantity of water" is considered because it is necessary forhydration of cement. Supply of water decreases in order of"water"→"wet+air"→"air", and it can be seen that the results follow thistrend. Therefore, strength decreases according to decrease of water supply

Examination concerning the acceptance inspection for quality assurance of structural concrete147

October 2009, Incheon, Korea

Compressive strength ratio

W/C=40%(Compres
sive strength)
OPC・BB

W/C＝60%(Compressive
strength)
BB

W/C＝60%(Compressive
strength)
OPC

W/C＝40%(Airpermeability)
OPC・BB

Air-permeability ratio

and air permeability increases. In the case of the lower water-cement ratio,
the compressive strength showed a similar tendency, but air permeability
did not change from "wet+air"→"air". Air permeability is generally related
to the quantity, size, and network of voids whereas strength is related to thequantity of voids and degree of hydration. Therefore, the change in strengthis an effective method to understand the degree of hydration, whereas thechange in air permeability can be used to understand change in the void
structure. Since the content of mixing water is low for low water cement
ratio, longer wet curing is necessary to develop pore structure. However
because the wet curing period is short, pore structure does not develop
enough, and voids do not close, so after wet curing free water may easily
evaporate. Furthermore, for air curing, the hydration reaction may bedelayed.

W/C＝60%(Airpermeability)
OPC・BB

Water

Wet+ Air

Air

Figure 4: Conceptual diagram of the influence of curing condition on air
permeability and compressive strength
The compressive strength and air permeability test results in case oflower water-cement ratio are considered as follows. Since the compressive
strength decreased in order of "water"→" wet+air"→" air,” less hydration
occurred in air curing than in wet curing. However, hydration development
under curing did not influence the results of the air permeability test.
Although hydration occurred under wet curing, development of hydration
product was not enough to reduce voids and decrease air permeability.
Possibly, hydration occurred just enough to influence the air permeability byaffecting the quantity of solid space (particles of cement and aggregate).
Particularly in the case of lower water-cement ratio, there is little water
available for hydration, so more non-hydrated cement is present than in thecase of high water-cement ratio. Therefore, under the curing period set by
the Japan Standard Specifications for Concrete Structures, it is believed thatthe curing was insufficient for air permeability because the degree ofhydration did not increase enough. By that reasoning, the change in air
permeability was confirmed in order of "water"→" wet+air". However, achange was not confirmed in order of "wet+air "→"air".

148

New Technologies for Urban Safety of Mega Cities in Asia

5

140

0

120
100

-5

80

-10

60

-15

40

-20

20

-25

Air-permeability ratio (%)

Compressive strength ratio (%)

Furthermore, when considering the influence of climate condition insummer and winter, the results followed the above tendency because thequantity of supplied water decreased in order of "water"→"wet+air"→"air".
On the other hand, in autumn the air permeability is around 50% for
W/C=40%, and around 70% for W/C=60%. This rate of change is much
lower than the other case (Fig. 5). In addition, compressive strength
decreased 5%, and the rate of change of “wet+air” and ”air” was similar too,
although air permeability did not change much for W/C=40%. When all theabove points are considered, the change ratio of both results is much smaller
than the case for lower water-cement ratio in particular. No change incompressive strength and air permeability was observed in the case of“wet+air”→”air”. It is possible that this was due to the high temperature andlarge volume of rainfall in autumn and the small difference in quantity ofwater supplied between the wet-curing and air curing conditions.

W/C=40%・Compressie strength
W/C=60%・Compressive strength
W/C=40%・Air-permeability
W/C=60%・Air-permeability

0
Water

Wet+Air

Air

Figure 5: Relationship between air permeability ratio and compressive
strength ratio (in autumn)

3.2 Result of tamping test
Result for slump flow and number of tamping times for variablefineness modulus of coarse aggregate are shown in Figure 6. The number oftamping times that is necessary to arrive at slump flow 450mm for finenessmodulus 6.82 and 6.68 is more than 10 times less than that for 7.07. The
measurement of the number of tamping times may evaluate consistency
more easily than slump because the result of the slump test was 10±1.5cm.
The upper circle of the sample could be confirmed until slump flow reached
300mm in the case of fineness modulus 7.07, but only until slump flow
reached 250mm for fineness modulus 6.82, and unable to be confirmed fromthe measurement start for fineness modulus 6.68. The validity of this result
was confirmed by the other research works, which also observed the change
in upper circle due to fineness modulus.
The effect of sand percentage was similar to that of fineness modulus.
Although initial slump was 8.5cm±1.0cm, the number of tamping times forsand percentage 50% was more than 10 times that for sand percentage 40%
and 45% (Fig. 7). The upper circle of the sample could be confirmed until

Examination concerning the acceptance inspection for quality assurance of structural concrete

149

October 2009, Incheon, Korea

slump flow reached 300mm for sand percentage 50%, but only until slump
flow reached 250mm for sand percentage 45%, and unable to be confirmed
from the measurement start for sand percentage 40%.

Number of tamping times

60
50

FM=6.6840

FM=6.8230

FM=7.07

20
10
0
200

300

400

500

Slump flow (mm)Figure 6: Relationship between number of tamping times and slump flow
(fineness modulus)

Number of tamping times

70
60

s/a=40%50

s/a=45%40

s/a=50%

30
20
10
0
200

300
400
Slump flow (mm)500

Figure 7: Relationship between number of tamping times and slump flow
(sand percentage)
To evaluate this more clearly, the “flow coefficient” was defined as
the slump flow divided by the slump. A high flow coefficient value
expresses that the slump greatly increases with increasing slump flow, but a
low flow coefficient value means that slump does not greatly increase withincreasing slump flow. Therefore, the upper circle remained in some cases
because the viscosity of the samples was high. For example, in the case ofsand percentage 50%, the flow coefficient was generally lower than theother cases, but in the case of sand percentage 40%, the flow coefficientsuddenly increased (Fig. 8), so the viscosity was low. In other words, since
the segregation resistance was low, segregation occurred immediately andthere was a possibility that the sample would collapse. To summarize, theflow coefficient could show the possibility of segregation resistance.
When water content per unit volume was changed, it was found that
evaluation by slump test was sufficient due to the large negative relationshipwhich was identified between the initial readings of slump and the numbers

150

New Technologies for Urban Safety of Mega Cities in Asia

of tamping times necessary to reach slump flow of 450mm. The upper circle
could be confirmed until slump flow of 450mm in the case of water content
per unit volume 156kg/m3. However, it could not be confirmed from themeasurement start in the case of water content per unit volume 186 kg/m3.
As a result, it was concluded that the evaluation of segregation resistance byflow coefficient was difficult (Fig. 9).

Flow coefficient

0.7
0.6
0.5

s/a=40%0.4

s/a=45%s/a=50%

0.3
0

20

40

60

Number of tamping times

Figure 8: Relationship between flow coefficient and number of tamping
times (sand percentage)
1
W=171kg/m3

Flow coefficient

0.9

W=186kg/m3

0.8

W=156kg/m3

0.7
0.6
0.5
0.4
0.3
0

10

20

30

40

50

Number of tamping times

Figure 9: Relationship between flow coefficient and number of tamping
times (water content per unit volume)

4. CONCLUSION
This study aimed to establish the acceptance inspection for securing thequality of structural concrete by conducting an experimental examination on
the effect of the assessment methods for resistance to mass transfer andsegregation resistance on durability. It was confirmed that the water-cement
ratio and curing method had an influence on compressive strength and air
permeability. Furthermore, it was found that in the actual environment, there
was a large difference between mix proportions. In the future, curing overother time period should be carried out so that segregation resistance can beunderstood quantitatively under different environmental conditions. To

Examination concerning the acceptance inspection for quality assurance of structural concrete151

October 2009, Incheon, Korea

evaluate segregation resistance, it is important that the presence of the upper
circle on the sample is confirmed when the slump test is performed. Finally,
it was shown that the transformation of the sample due to changes insegregation resistance might be estimated quantitatively. Previously
established tests for evaluate viscosity should be conducted to more clearly
understood these changes and to compare with the results in this paper.
REFERENCES
The authors would like to express their thanks to Mr. Michael W. Henry
who generously assisted.
REFERENCES
JSCE, 2007. Japan Standard Specifications for Concrete Structures, pp. 122124.
Ishii, Y., Uji, K., Ueno, A., 2008. A study on quantitiative evaluation of air
permeability of concrete. Proceedings of the Japan Concrete Institute Vol.30
No.2, pp. 37-42. (in Japanese)
Ujiie, I., Nagataki, S., 1988. Simple method for evaluation of workability by
tamping test. Journal of Materials, Concrete Structures and Pavements,
JSCE, Japan. (in Japanese)152

New Technologies for Urban Safety of Mega Cities in Asia

ESTIMATION OF SEISMIC CAPACITY OF
KOREAN TYPICAL SCHOOL BUINDINGSUNDER DESIGN RESPONSE SPECTRUM
HO CHOI
Institute of Industrial Science, The University of Tokyo, Japan
choiho@iis.u-tokyo.ac.jp
YOSHIAKI NAKANOInstitute of Industrial Science, The University of Tokyo, Japaniisnak@iis.u-tokyo.ac.jp

ABSTRACTIn the current seismic design provisions of Korea, school buildings
are specified as evacuation shelter after an earthquake and are constantly
requested the seismic design. However, there are no investigations onwhether existing school buildings can play a role as evacuation shelter
against future earthquakes.
In this study, the seismic capacity and the damage class of existing
typical school buildings in Korea are therefore analytically estimated. For
this purpose, a 4-story frame including unreinforced concrete block walls
based on the standard design of Korean school buildings in the 1980s is
selected as a model structure, and 6 artificial ground motions
corresponding to Korean design response spectrum level are used toestimate the seismic capacity of the model structure.
All of the analysis results of first story for 6 artificial ground motions
exceed the maximum strength and reach in the state of damage class III
through V. This result means that existing typical school buildings in Korea
do not escape at least moderate damage and then may not be able to play arole as evacuation shelter against the earthquakes of Korean design
acceleration level.

1. INTRODUCTION
In Korea, countermeasures against earthquake disasters such as the seismic
capacity evaluation and/or retrofit schemes of buildings have not been fully
performed since Korea had not experienced many destructive earthquakes in
the past. However, due to more than eight hundred earthquakes withslight/medium intensity in the off coastal and inland of Korea during thepast 30 years as shown in Figures 1 and 2, and due to the recent greatearthquake disasters in neighboring countries, such as the 1995 Hyogoken-

153

October 2009, Incheon, Korea

Figure 1: State of earthquake occurrence in Korea after 1978

Number of EQ. occurrence60

M >3.0Total number

50
40
30
20
10
0

1980

1985

1990

1995

2000

2005

Year

Figure 2: Frequency rate of earthquake occurrence
Nanbu Earthquake with more than 6,500 fatalities in Japan and the 1999
Chi-Chi Earthquake with more than 2,500 fatalities in Taiwan, theimportance of the future earthquake preparedness measures in Korea ishighly recognized.
Seismic design provisions for building structures in Korea first wereintroduced in 1988 and were revised in 2000 and 2005. Since the seismic
design, however, was requested for the buildings more than 6 stories before
2005, school buildings which are mainly less than 5 stories have been
excluded from the seismic design. In the current seismic design provisionsof Korea, school buildings are specified for the first time as evacuation
shelter after an earthquake and are constantly requested seismic design
regardless of the number of stories. However, there are no investigations onwhether existing school buildings can play a role as evacuation shelter
against future earthquakes.

154

New Technologies for Urban Safety of Mega Cities in Asia

In this study, the seismic capacity and the damage class of existing typicalschool buildings in Korea are therefore analytically estimated under Korean
design response spectrum level. For this purpose, a 4-story frame including
unreinforced concrete block (CB) walls based on the standard design of
Korean school buildings in the 1980s is selected as a model structure, and 6
artificial ground motions corresponding to Korean design response spectrum
level are used to estimate the seismic capacity of the model structure.

2. OUTLINE OF MODEL STRUCTURE
Figure 3 shows a standard design of Korean school buildings in the 1980s(The Ministry of Construction and Transportation, 2002). In this study, the4-story RC frame including CB walls as shown in this figure is analyticallyinvestigated as a model structure. Since seismic design provisions forbuilding structures in Korea first were introduced in 1988 as mentioned
above, the model structure studied herein is not designed to seismic loads.
Therefore, they have (1) large spacing of hoops (300mm) and (2) 90 degree
hook at both ends of hoops. The design strength of concrete is 21N/mm2,
and the deformed bar SD40 (nominal yield strength: 395N/mm2) is used for
longitudinal and shear reinforcement. The size of a CB unit is 390×190×190mm. It has three hollows inside and a half-sized hollow on both ends.
Longitudinal dir.

10,000

4,500

4,500

4,500

4,500

C2

C2

C2

C2

C1

C1

C1

C1

7,500

2,500

Transverse
dir.

[Column]
C1 col.
C1 col.
(left side) (right side) *B×D : 400×450 (C1)
400×400 (C2)
C2 col.
*Main reinforcement : 8-D19*Hoop : D10@300
IW4
C2[Concrete block]*390×190×190
C1*Effective sectional area
: 46,700mm2(excluding the hollow)
IW1

C1

C1

C1

C1

C1

[unit:mm]

Figure 3: Standard design of Korean school buildings in the 1980s andmodel structure

3. SEISMIC CAPCITY AND DAMAGE CLASS OF EXISTINGTYPICAL SCHOOL BUILDING IN KOREA
3.1 Hysteretic characteristics of model structure
In this section, shear strengths of each column and CB wall arecalculated based on the test results previously performed, and the loaddeformation curves of each story are determined with a simplified model.
3.1.1 Outline of experiment
In order to calculate the shear strengths of each column and CB wallof the model structure, the test results previously performed by authors arereferred (Nakano and Choi, 2005). In the tests, 2 specimens representing a

Estimation of Seismic Capacity of Korean Typical School Buildings under Design Response Spectrum

155

October 2009, Incheon, Korea

first or fourth story of 4-story RC school buildings are investigated asshown in Figure 3. They are an infilled wall type (IW1) assuming the firststory and an infilled wall type 2 (IW4) assuming the fourth story. Material
properties of C1 and C2 columns (see Figure 3) obtained the test results areshown in Table 1. Although the design strengths of concrete andreinforcement specified in the standard design of Korean school buildings in
the 1980s are 21N/mm2 and 395N/mm2, respectively, as mentioned in theprevious chapter, those strengths exceed the design values. Figure 4 shows
the relation between the lateral load and the drift angle of specimens IW1
and IW4. Assuming the discrepancy between the observed peak load ofoverall frame and the calculated shear strength of both columns is carried by
the CB wall, the average shear stresses B of CB wall to sectional area A
including hollow (A=390×190mm) for both specimens are identically
0.4N/mm2 as plotted in Figure 4.
1200
900

B = 4.0 N/mm

2

Specimen IW1

Specimen IW4
B = 4.0 N/mm

2

Load (kN)

600
300
0
-300

Ry

Ru

Ru

Ry

Axial stress
4.0MPaAxial stress
1.0MPa-600-900
Calculated shear strength for both columns-1200-2.5-2.0-1.5-1.0-0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 -2.5-2.0-1.5-1.0-0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
Drift angle, R (%)
Drift angle, R (%)

Figure 4: Load vs. drift angle of specimens IW1 and IW4Table 1: Material properties of C1 and C2 columns
Compressive Yield strength of Yield strength ofColumn Column Column
longitudinaltransverse
strength
Col. width depth heightof concrete reinforcement shear reinforcementb (mm) D (mm) h0 (mm)Fc (N/mm2)
y (N/mm2)
wy (N/mm2)
C1
400
450
2,800
26.2
432
404
C2
400
400

3.1.2 Determination of hysteretic characteristics
To simulate the inelastic behaviors of the model structure, the loaddeformation curve is represented by a simplified hysteretic model withassumptions (1) through (3) described below.
(1) The Takeda model is employed for the basic hysteretic rule assuming (a)no hardening in post-yielding stiffness and (b) stiffness degradation
factor  of 0.7 derived from the test results during unloading.
(2) Table 2 shows the shear strengths of each column and CB wall
calculated using each value of Figure 4 and Table 1. The yield load Qy issimply calculated as the sum of shear strengths of three columns and156

New Technologies for Urban Safety of Mega Cities in Asia

one CB wall, and the average shear stress B of the CB walls for eachstory are identically assumed 0.4N/mm2 from test results. The yield drift
angle Ry for each story is equally assumed 0.67%, and the load Qcr anddrift angel Rcr at cracking point are assumed Qy/3 and Ry/15,
respectively, based on test results.
(3) The ultimate ductility factors  of specimens IW1 and IW4 defined by
Ru/Ry, where the ultimate drift angle Ru is defined as the drift angle
when the lateral load carrying capacity decreases to 80% of the peakload, are approximately 2.0 and 3.0 (see Figure 4). According to thisresult, the factors  of first story through forth story are assumed 2.0,
2.5, 2.5 and 3.5, respectively.
Figures 5(a) through 5(d) shows the load-deformation relation of eachstory determined by assumptions above together with damage classdetermined by definition for RC members in the Guidelines for PostEarthquake Damage Evaluation and Rehabilitation of RC Buildings in Japan(2001) shown in Figure 6.
3.2 Korean design response spectrum and artificial ground motion
In this section, design response spectrum provided Korean seismic
design provisions is discussed, and artificial ground motions corresponding
to design response spectrum are determined.
In the current seismic design provisions of Korea, general response
spectrum with 5% of critical damping can be obtained by the design shortperiod spectral response acceleration parameter of SDS and the design
spectral response acceleration parameter at one second of SD1 as shown inequation (1) (Architectural Institute of Korea, 2005). Figure 7 shows
spectral response acceleration determined by equation (1). The parameters
SDS and SD1 are determined respectively from Tables 3 and 4, based on thesite class and the seismic zone as shown in Tables 5 and 6, respectively. In
this study, site class, SC, at seismic zone 1 is selected since the soil type of
Korea mainly consists of soft rock.

S DS
T  0.4S DS
T0

S a  0.6
S a  S DSSS a  D1
T

for 0  T  T0
for T0  0  TS

(1)

for T  TS

where, T0 and TS are given by the equations (2) and (3).

T0  0.2
TS 

S D1
S DS

S D1
S DS

Estimation of Seismic Capacity of Korean Typical School Buildings under Design Response Spectrum

(2)
(3)

157

October 2009, Incheon, Korea

Table 2: Shear strengths of each column and CB wall
C1 column(right side)
Axial
Shear
force
strength
N (kN)Qc (kN)
165
109
331
131
496
150
662
168

Story

4
3
2
1

Damge class

I II III IV V

1200

C1 column(left side)
Axial
Shear
force
strength
N (kN)Qc (kN)
221
116
441
144
662
168
882
190

800
600

Hysteretic characteristicsof 3 columns and 1 CB wall

400

0
0.0

800

0.5

1.0 1.5 2.0 2.5
Drift angle, R (%)

3.0

3.5

Damge class600

Hysteretic characteristicsof 3 columns and 1 CB wall

400

I II

III

IV V

Damge class

Hysteretic characteristicsof 3 columns and 1 CB wall

400

3.5

IV V

Damge class

800
600
400

Hysteretic characteristicsof 3 columns and 1 CB wall

200
3.5

III

Ultimate drift angle(Ultimate ductility factor  = 3.0)

1000

200
3.0

II

I

1200

Ultimate drift angle(Ultimate ductility factor  = 2.5)

0.5Ry Ry
2.0Ry 2.5Ry0
0.0 0.5 1.0 1.5 2.0 2.5
Drift angle, R (%)3.0(b) Second story

Load (kN)

Load (kN)

600

IV V

521

Ultimate drift angle(Ultimate ductility factor  = 2.5)(a) First story

800

III

Shear
strength
QB (kN)

0.5Ry Ry
2.0Ry 2.5Ry0
0.0 0.5 1.0 1.5 2.0 2.5
Drift angle, R (%)

0.5Ry Ry 1.5Ry 2.0Ry

1000

Shear
strength
Qc (kN)
84
91
97
103

200

200

1200

CB wall

1000

Ultimate drift angle(Ultimate ductility factor  = 2.0)

Load (kN)

Load (kN)

Axial
force
N (kN)
55
110
165
221
I II

1200

1000

C2 column

00.0

Ry 1.5Ry 2.5Ry 3.0Ry
0.5

1.0 1.5 2.0 2.5
Drift angle, R (%)

3.0

3.5

(c) Third story(d) Fourth story
Figure 5: Load-deformation relation of each story
Lateral load
Vertical load

Load carrying capacity

Damage class

Remained

Deteriorated Lost

Remained

Lost

I

II

III

IV

V

Compression failureof conc. starts
Yielding oftensile rebars

Buckling of rebars /falling of covering conc.

Cracking

Deformation

Figure 6: Schematic illustration of damage class (Ductile member)

158

New Technologies for Urban Safety of Mega Cities in Asia

Spectral response acceleration, Sa

Sa = 0.6

SDS
T + 0.4SDS
T0

SDS
Sa =
SD1

SD1
T

SDS
2.5

TS

T0

1.0
Period, T (sec.)

Figure 7: General response spectrum
Table3: Short-period spectral response Table4: Spectral response acceleration
acceleration parameter, SDS
parameter at one second, SD1
Seismic zone, A
Seismic zone, A
Site
Site
class
class
1
2
1
2
SA
2.0M*1A*2
1.8MA
SA
0.8MA
0.7MA
SB
2.5MA
2.5MA
SB
1.0MA
1.0MA
SC
3.0MA
3.0MA
SC
1.6MA
1.6MA
SD
3.6MA
4.0MA
SD
2.3MA
2.3MA
SE
5.0MA
6.0MA
SE
3.4MA
3.4MA
*1 M =1.33 (M is a response acceleration parameter at 2%/50 year probability of exceedance(2,400 years of mean return period))*2 A : Seismic zone factor (see Table 6)

Table 5: Site classes in Korea
Site
class

Soil class

Shear wave
velocityVs (m/s)

SA
SB
SC
SD
SE

Hard rockRock
Very dense soil, Soft rock
Stiff soil
Soft clay>1,500760 - 1,500
360 - 760
180 - 360<360Standard
Undrained
penetration test
shear strength
blow countSu (×10-3N/mm2)
N (/300mm)>50>100
15 - 50
50 - 100<15<50

Table 6: Seismic zone factor corresponding to each zone
Seismic zone
1

2

Zone
All of zone
Exceptseismic zone 2
North Gangwon-do,
South Jeolla-namdo,
Jeju-doSeismic zone factor
A

Remarks
0.07

0.11
0.11

0.07

0.07

Estimation of Seismic Capacity of Korean Typical School Buildings under Design Response Spectrum

159

October 2009, Incheon, Korea

Acc. (cm/sec )

600
400
200
0
-200
-400
-600

Kobe 1995 (NS)Max Acc.=-821.0gal

Acc. (cm/sec )

600
400
200
0
-200
-400
-600

Hachinohe 1968 (EW)Max Acc.=183.0gal

Acc. (cm/sec )

600
400
200
0
-200
-400
-600

Tohoku univ. 1978 (NS)Max Acc.=258.0gal

600
400
200
0
-200
-400
-600
-800

Uljin 2004 (NS)Max Acc.=72.5gal

2

2

2

2

2

Acc. (cm/sec )

800
600
400
200
0
-200
-400
-600

Acc. (cm/sec )Since the earthquakes of maximum acceleration level specified in thecurrent seismic design provisions of Korea have not been occurred, 6
artificial ground motions herein are used to estimate the seismic capacity ofthe model structure. The following 6 records are used to determine phaseangles of ground motions: the NS component of El Centro 1940 record(ELC), NS component of Kobe 1995 record (KOB), EW component ofHachinohe 1968 record (HAC), NS component of Tohoku University 1978
record (TOH), NS component of Uljin 2004 record (ULJ) which has thehighest maximum acceleration among the earthquake data measured by
Korean meteorological office, and random excitation (RAN). Figure 8
shows 5 earthquake record data except random excitation, and Figure 9shows the elastic acceleration response spectra of artificial ground motions
with 5% of critical damping corresponding to the design response spectrumat seismic zone 1 and site class, SC.
El Centro 1940 (NS)Max Acc.=341.7gal

0

5

10

15

20
Time (sec.)

25

30

35

40

Figure 8: Earthquake record data

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New Technologies for Urban Safety of Mega Cities in Asia

500
Artificial wave
Target spectrum* Seismic zone 1
Site class SC

2

SA (cm/sec )

400
300

* Dampin ratio, h=0.05
200
100
0
0.0

0.5

1.0
1.5
2.0
Predominent period, T (sec)

2.5

3.0

Figure 9: Elastic acceleration spectra of artificial ground motions
3.3 Seismic capacity and damage class of existing typical school buildingin KoreaIn this section, the seismic capacity and the damage class of existing
typical school buildings in Korea, which should be properly functional as
evacuation shelter as well as structurally safe after an earthquake, areanalytically investigated using the hysteretic characteristics and 6 artificial
ground motions mentioned in previous sections.
Figure 10 shows the inelastic behaviors of first story, where the mostserious damage is found, for 6 artificial ground motions together with thedamage class. As shown in this figure, the behaviors and damage classes areslightly different due to phase angles of each ground motion. However, allof analysis results exceed the maximum strength and reach in the state ofdamage class III. The results due to KOB, HAC and RAN particularly
exceed the ultimate drift angle of 1.35% and reach in the state of damage
class V (i.e., collapse). For the RC frame without CB wall, more serious
damages are expected since the lateral load carrying capacity is relatively
small than that with CB wall. This result means that existing typical schoolbuildings in Korea do not escape at least moderate damage and then may not
be able to play a role as evacuation shelter against the earthquakes of
Korean design acceleration level.

4. CONCLUSIONSThe seismic capacity and the damage class of Korean school buildings,
which should play a role as refuge facilities after an earthquake, areanalytically estimated under Korean design response spectrum level basedon the test results. All of the analysis results of first story for 6 artificial
ground motions exceed the maximum strength and reach in the state ofdamage class III through V. It is revealed that existing typical schoolbuildings in Korea do not escape at least moderate damage and then may not
be able to play a role as evacuation shelter against the earthquakes of
Korean design acceleration level.

Estimation of Seismic Capacity of Korean Typical School Buildings under Design Response Spectrum

161

1200

I

Damage class
II III IV

900

KOB

600

Load (kN)

ELC

Load (kN)

October 2009, Incheon, Korea

1200

0-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)
-600

900
600

0
-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)-600

I

Damage class
II III IV

900

TOH

600

Load (kN)-900I
IV III II-1200
Damage class

Load (kN)-900I
IV III II -1200
Damage class
HAC

1200

0
-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)
-600

600

0
-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)-600

I
IV III II-1200
Damage classI
IV III II-1200
Damage class
I

Damage class
II III IV

900
600
300

0
-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)
-600

RAN

Load (kN)-900

Load (kN)

Damage class
II III IV

900

-900

ULJ

I

300

300

1200

Damage class
II III IV

300

300

1200

I

1200

I

Damage class
II III IV

900
600
300

0
-1.2 -0.8 -0.4 0.0 0.4 0.8 1.2-300
Drift angle, R (%)
-600

-900

-900

I
IV III II-1200
Damage classI
IV III II-1200
Damage class

Figure 10: Inelastic behaviors and damage class of first story

REFERENCES

The Ministry of Construction and Transportation, 2002. A Study on the
Seismic Evaluation and Retrofit Low-Rise Buildings in Korea. pp.113-155.
Nakano, Y. and Choi, H., 2005. Experimental Study on Seismic Behavior
and Crack Pattern of Concrete Block Infilled RC Frames. New Technologies
for Urban Safety of Mega Cities in Asia (USMCA), ICUS/INCEDE Report 2,
Singapore.
JBDPA (The Japan Building Disaster Prevention Association), 2001.
Guidelines for Post-Earthquake Damage Evaluation and Rehabilitation.
AIK (Architectural Institute of Korea), 2005. Commentary on the Guideline
for the 2005 Korea Building Seismic Code.

162

New Technologies for Urban Safety of Mega Cities in Asia

SHAKING TABLE TESTS OF
TRADITIONAL TIMBER FRAMESINCLUDING KUMIMONO– MODELING OF HORIZONTALRESISTANCE FORCE IUKO TSUWA
Graduate School of Engineering, the University of Tokyo, Japantsuwa@iis.u-tokyo.ac.jp
MIKIO KOSHIHARA
Institute of Industrial Science, the University of Tokyo, Japan
kos@iis.u-tokyo.ac.jp

ABSTRACTThis paper presents the results of the shaking table tests of traditionaltimber frames with mud wall and without it. The aim of this research is toclarify the vibration characteristics of the whole frames and structuralelements which are column, Nuki, Kumimono, and mud wall, and to identify
the difference of the behaviour about Kumimono in two types of specimens.
The results of the specimen with mud wall were compared with thoseof one without mud wall. The way to model stiffness of each element andboth whole frames is discussed using the previous theory and experimental
and material results. It is clarified that the relationship between load anddisplacement of a whole frame can be evaluated by adding the restoring
force characteristics of each structural element. The restoring force
characteristics of Kumimono have a very small effect on one of a frame
because the stiffness of Kumimono is much higher than one of column andmud wall.

1. INTRODUCTION
Traditional timber structures have been built by empiricalknowledge of carpenters. However recently the quantitative evaluation of
their structural behaviours is needed in order to build new traditional timber
structures or for restoration works of such structures. Therefore thequantitative evaluation of their structural behaviors is indispensable. In thebuildings such as temples and shrines, column, mud wall, Nuki which is atie beam extending from one pillar to another, and Kumimono which is a
structural component between a column and roof, etc, are considered as
structural elements. Each element has been researched and modeled
experimentally and analytically. However it is not clear how each element163

October 2009, Incheon, Korea

contributes to the whole structural behavior. In this study, shaking table tests
were performed with the two types of specimens. One specimen consistedof columns, Nuki, and Kumimono. Another one included mud wall with theother type. The aim of this research is to clarify the vibration characteristics
of each element in a frame and the difference of the behavior about
Kumimono in the two types of specimens.

2. OUTLINE OF EXPERIMENT
2.1

Test specimens

The specimens were the 2/3 scale model of a frame in the Asuka styleof the five-storied timber pagoda as shown in Figure 1. The span between
columns was an outside plane of structure in the first story of the pagoda as
shown in Figure 1, in order to clarify the modeling method of the structuresconsisting of Nuki, columns. Kumimono modeled the parts of 2 pairs on thecentral two columns because Kumimono in corners is projecting at 45degree angle in a flat and has complex forms and the aim of this study wasto get basic data of each element. A cornerstone was put under each column.
They were connected with a dowel. Tree species were yellow cedar.
Two types of specimens were used in the tests as shown in Figure 2.
Specimen 1 consisted of columns, Nuki, and Kumimono. Specimen 2 wasmade by adding mud wall between the columns of the Specimen 1.

The part of Kumimono(a) Elevation(b) Plan
Figure 1: Subject plane of structure

3060
1260

900

The part below
Kumimono

900

726

Toshi-hijiki
Kumimono
Daiwa
2706

Column1980

300

Mud wall300
Koshi-nuki

Ji-nuki164

Mud wall

New Technologies for Urban Safety of Mega Cities in Asia

Figure 2:Specimens
2.2 Experimental method
The shaking table tests were carried out at the shaking table of Chiba
Experiment Station of Institute of Industrial Science, the University ofTokyo. Horizontal unidirectional shaking was conducted. Figure 3 showsthe experimental method. The vertical load of 39.9kN made of steel frames
and lead was put on the specimen. A load cell to measure axial force andshear force was placed under each column. The acceleration, displacement
and the strain of specimens were measured using about 75 devices.
BCJ-L2, the level 2 of a simulated wave provided from the building
center of Japan, was used as a large input motion. In the tests of Specimen 1,
the maximum input acceleration was increased by 10% from 10% (35.6 gal)to 100% (356 gal). In the tests of Specimen 2, one input with BCJ-L2 20%
and two inputs with BCJ-L2 100% were carried out.
Support frame
Pantograph726

Vertical load

2706

300

Specimen

300

300

1980

1260

Dowel

Cornerstone

285

Load cell
Shaking table
East -+ WestFigure 3: Experimental method

3. EXPERIMENTAL RESULTS
3.1 The relationship between load and displacement
Figure 4 shows the relationship between load and displacement fromthe inputs of BCJ-L2 20%, 40%, 80%, 100% to Specimen 1. Until the testof 20%, the relationship between load and displacement was linear. Afterthe test of 30%, the relationship became nonlinear. The stiffness went downat the displacement of about 5mm. After the yield point, the hysteresis curve
became swollen. The negative gradient appeared in the deformation fromthe maximum to the origin. The maximum shear force was 10.75kN at thetest of BCJ-L2 80%. The maximum displacement was 180.2mm, 1/13raddeformation angle of a column, at the test of BCJ-L2 100%. After the

Shaking table tests of traditional timber frames including Kumimono

165

October 2009, Incheon, Korea

experience of a large deformation, a load around an origin point wasincreased drastically8

Load (kN)

20%

10

40%

6

4

4

2

-3

-2

2

Displacement (mm)

0
-6

0

6 -30

3

-20

-10

-2 0

20

30

-6

-6

-8

-8

-10

15

15

Load (kN)

100%

10

Load (kN)

1055Displacement (mm)

0
-50

10

-4

80%

-100

Displacement (mm)

0

-4

-150

Load (kN)

8

6

0
0

50

100

150 -200

-100

0

-5

-5

-10

-10

-15

-15

100
200
Displacement mm)

Figure 4: The relationship between load and displacement of Specimen1
Figure 5 shows the relationship between load and displacement for the
inputs of BCJ-L2 20% and BCJ-L2 100% to Specimen 2. In the test of BCJL2 20%, the stiffness was higher than that in the test of 20% for Specimen 1.
It was assumed to be due to the resistance of the mud wall.
In the first BCJ-100%, the load went up to about 12kN within 40mm
displacement. It can be assumed to be due to the resistance force of the mud
wall. After the collapse of the mud wall, the resistance force of the specimen
dropped and a hysteresis curve changed to a gray line in Figure 5. Therefore,
in the test of the second BCJ-100%, the load did not rise like the first one.
At around 5kN load, the stiffness changed and a load increased gradually up
to around 10kN.

Restoring
Force （ｋN)

20%

15

Restoring
Froce (kN)

100%
10

10

5

5

0
-10

-5

0
0

-5

166

15

5
10
Displacement （mm）

-150

-100

-50

0
-5

-10

-10

-15

-15

50

100
150
Displacement （mm）

Before collapse of wall
After collapse of wall

New Technologies for Urban Safety of Mega Cities in Asia

Figure 5: The relationship between load and displacement of Specimen2
Figure 6 shows the relationship between load and displacement for
BCJ-L2 100% of Specimen 1 and Specimen 2. The characteristics of every
hysteresis curve were almost same after the collapse of the mud wall.
However the load of Specimen 2 in the range of less 50mm became higher
than that of Specimen 1. It can be assumed to be due to the resistance forceof mud wall.

Restoring
Froce (kN)

100%

15

10

5

0
-200

-150

-100

-50

0

50

100
150
200
Displacement （mm）

-5

Specimen 2 (Before collapseof wall)Specimen 2 (After collapseof wall)Specimen 1

-10

-15

Figure 6: The comparison of the relationship between loadand displacement
3.2 Deformation
Figure 7 shows the horizontal deformation of specimens in the rangeof the maximum amplitude from the test of BCJ L2 100%. Most of thedisplacement of Specimen 1 was the displacement from the inclination ofcolumns. The line between Daiwa and Toshi hijiki was vertical almost all
time. It means that the displacement of Kumimono was very minute. As forSpecimen 2, the characteristic was almost same. However, at the maximum
deformation, the line between Daiwa and Top inclined. It can be seen thatthe deformation of Kumimono increased slightly.
Specimen 2 (100%-2)

Specimen 2 (100%-1)

Specimen 1
Deformation Direction

Displacement (mm)
-200

-100

0

100

200

Displacement (mm)Displacement (mm)
-200

-100

0

100

200

-200

-100

0

100

200

Figure 7: Behavior in 100% tests
3.3 The share force at the bottom of columns

Shaking table tests of traditional timber frames including Kumimono

167

October 2009, Incheon, Korea

Figure 8 shows the share force measured at the bottom of columns ofSpecimen 1. Each share force of right and left columns went up and downwith the opposite stiffness. It is because the compressive force occurred at
Jinuki and the force toward a direction spreading the width of columns
happened when both columns leaned.
20

Shear force
（kN）

15
10
5
0
-200
-150
-100
Displacement （mm）

-50

0

50

100

150

200

-5
-10
-15

Column (right)
Column （left）-20

Figure 8: The Shear force at the bottom of columns

4. Modeling of each element
Whole frames including columns, compressive strains inclined to the grain
at Koshinuki and Jinuki, Kumimono, and Mud wall were modeled as shownin Figure 9. The restoring force of each element was calculated by themeasurement values from experiments or material experiment results. Eachelement model is as follows.

Kk :Spring of Kumimo
Kc +Kn+Kj+Kw: Spring of Column, compressive
strains inclined to
the grain at Koshinuki and Jinuki,
and Mud wall
Figure 9: The model of a whole frame
4.1 Restoring force of Column
Restoring force of columns was calculated with reference to previous
experiments and researches of Ban, 1942 and Kawai, 1992.
(1)
y=H0{1-δ/b＋0.99625e-7.5675δ/b - 1.9963/(25δ/b＋１)}
y: Restoring force, δ: Horizontal displacement, b: Diameter of column,
H0: = Pb/h Restoring force of rigid body, h: The length of column,
The factor b considered the rabbet like Figure 10. The maximum of
restoring force was 80% of H0. The horizontal displacement of this force

168

New Technologies for Urban Safety of Mega Cities in Asia

was 0.088 times of a column width. Assuming that two columns wereconnected with a parallel spring, the stiffness of both columns can be added.
In addition, it is assumed that deformation and vertical load of both columns
were same.
Pδ

H

Sheareforce (kN)

6
4

hh

2

θ

Deformation angle (rad.)

0
-0.1

θ

-0.05

0

0.05

0.1

-2
-4
-6

Figure 10: The model of a column

Figure 11: The restoring force
of columns

4.2 Evaluation of Koshinuki
Perfect elastoplasticity hysteresis shown in Figure 11 and 12 wasgiven by using Merikomi theory (Inayama, 1992) , the theory for calculating
the theoretical stiffness of timber perpendicular to the grain, based on the
hypothesis that compressive strains inclined to the grain were at placeshown in Figure 12. On the other hand, bending moment of Koshinuki
measured by strain gauges was given from experiment results. By the values
and calculating deformation angle of the column-Koshinuki joint, rotational
stiffness was calculated. Figure 13 and 14 show the rotational stiffness of
the right column-Koshinuki joint in Specimen 1 and 2. In both specimens,
experimental results from strain gauges were higher than theoretical ones.
For this reason, hysteresis curves like heavy line in Figure 13 and 14 weremodeled.
4500
3500

Column柱(西)ーθ(kN・mm)

2500

d/2

1500
500

Koshinuki
腰貫
-0.1

-0.05

d/2
＋

モーメント
Moment-500 0
-1500

d

-2500

0.05

0.1

Rotational 接合部の回転角(rad.)angle (rad.)Specimen 1
試験体１
Model
モデル化

-3500

Theory
めり込み理論-4500

Figure 12: The place of compressive strains Figure 13: The restoring forceof Koshinuki (Specimen 1)
4500Moment
3500(kN・mm)
2500
1500
500
-0.12

-0.08

-0.04 -500 0

0.04

0.08

0.12

-1500

Rotational angle (rad.)-2500

Specimen 2
Model
Theory

-3500
-4500

Shaking table tests of traditional timber frames including Kumimono

169

October 2009, Incheon, Korea

Figure14: The restoring force of Koshinuki (Specimen 2)
4.3 Evaluation of Jinuki
After experiments, compressive strains inclined to the grain occurred
due to the joint of columns were observed on Jinuki. By calculatingrotational stiffness assuming that compressive strains occurred at places
shown in Figure 15, first stiffness became 146,000 kN･mm/rad., and yieldresistance were 1,982 kN･mm. By using the theoretical values, the restoring
force as shown in Figure 16 were given because no measurement values like
Koshinuki were.
4

Column柱(西)θShear force
(kN)

3
2

d

1
0
-0.1

-0.05

0
-1

Jinuki
地貫

0.05

0.1

Rotational deformationof a column (rad.)

-2
-3
-4

Figure 15:The place of compressive strains Figure 16: The restoring forceof Jinuki
4.4 Restoring force of Kumimono
The horizontal displacement of Kumimono was calculated bysubtracting one of Daiwa from one of top. The relationship between loadand displacement of Kumimono was gained shown in Figure 17. Restoring
force of Kumimono in Specimen 1 and 2 were evaluated like heavy lines in
Figure 17.
15

Shear 15
force (kN)Shear force
(kN)

10

10

5

5
0

0
-20

-10

0
-5
-10

10
20
Displacement （mm）

Experiment
Model

-15

-20

-10

0
-5
-10

10
20
Displacement (mm）Experiment
Model

-15

Figure 17: The restoring force of Kumimono

4.5 Restoring force of Mud wall170

New Technologies for Urban Safety of Mega Cities in Asia

In order to figure the strength of mud wall out, material tests for mud
wall were performed as shown in Figure 18. From the results, the hysteresis
curve of mud wall was modeled like a heavy line shown in Figure 19.
Load

Load [kN]

16.0
14.0
12.0
10.0
8.0
6.0

Experiment
Model

4.0
2.0

Deformation angle [rad.]

0.0
0.00

Figure 18: Material test

0.02

0.04

0.06

0.08

0.10

Figure 19: The restoring force of mud wall

5. Analysis Results and Discussions
The restoring force characteristics of Specimen 1 and 2 given byadding each hysteresis model shown above were compared with the loaddeformation relationship given by experiments. Figure 20 shows thehysteresis curve given by adding downside elements of columnm, Nuki, andmud wall. Figure 21 shows the hysteresis curve given by adding a model
shown in Figure 20 and Kumimono. It is assumed that no restoring force ofcompressive strains inclined to the grain occurred during unloading. It isclarified that experimental model corresponds to theoretical one. The
restoring force can be calculated by adding each restoring force model of
elements.
It can be seen that in the range of the first stiffness, the ratio of therestoring force of columns is the highest in Specimen 1. In the range of
deformation more than 100mm, one of Koshinuki is high. On the other hand,
the ratio of restoring force for mud wall is the highest in the Specimen 2.
After collapse of mud wall, the restoring force of Koshinuki accounts forhigh percentage of the whole bearing force. The horizontal derfomation of
Kumimono was very little in both specimens.
Shear force 15(kN)

Shear force 15(kN)

Specimen 1

10

10

5

5
0

0
-200

-100

Specimen 2

0
-5

100
200
Displacement （mm）

-200

-100

-15

100
200
Displacement （mm）

-5

Experiment
Theory (uploading)
Theory (unloading)ColumnKoshinuki
Jinuki-10ｖ0Experiment （Top displacement）
Downside elements（uploading）
Downside elements（unloading）
ColumnKoshinuki
JinukiM d ll-10-15

Figure 20: The comparison between experimental and theoretical results(Structural elements without Kumimono)
Shear force
(kN)

10

10

5

5

-100

0

100
200
Displacement （mm）

-5
-10Specimen 2

0

0
-200

Shear force 15(kN)

Specimen 1

15

Experiment (Top displacement)
Downside elements（uploading）
Downside element（unloading）
Model (Kumimono）
All (uploading）
All （unloading）-15

Shaking table tests of traditional timber frames including Kumimono

-200

-100

ｖ

0
-5
-10
-15

100

200

Displacement （mm）
Experiment （Top displacement）
Downside elements（uploading）
Downside elements（unloading）
Model（Kumimono）
All（uploading）
All （unloading）

171

October 2009, Incheon, Korea

Figure 21: The comparison between experimental and theoretical results(Structural elements including Kumimono)
6. CONCLUSIONS
Shaking table tests were performed using a traditional timber frame
consisted of columns having large diameter, Kumimono, Nuki. Specimens
were with mud wall and without one. It is found that the restoring force
characteristics of Kumimono in both specimens have a very small effect on
one of a frame. It is because the stiffness of Kumimono is much higher than
one of column, Nuki and mud wall making the weakest structural frames in
traditional timber structures. It is clarified that the relationship between loadand displacement of a whole frame can be evaluated by adding the restoring
force characteristics of each structural element.

ACKNOWLEDGMENT
The specimens used in the tests were made by master carpenter Mr.
Yasugoro Kaneko of Fudosyaji. The tests were performed with staff andstudents of Koshihara Laboratory, Yosuke Simawaki, Assistant, Mr. Hideo
Otsuka, a Technical Staff, Dr. Kim Hye Won, Postdoctoral Fellow, Mr. Kei
Kato, a Graduate Student, and Ms. Tomoka Takase, an Undergraduate
Student of Isoda Laboratory at Shinshu University. The authors wish to
express their sincere gratitude to all of people above for their generosity andhelp without which this experiment could not be accomplished.
REFERENCES
Ban, S., 1942. A study on the determination of the stability about main hall
structures, Vol. 3: a mechanical study on the Japanese Traditional Frame, 1,
the stability restoring force of a column. March, 252-258. (in Japanese).
Kawai, N., 1992. A study on the structural stability of traditional timber
structures, The Building Center of Japan, March. (in Japanese).
Inayama, M., 1991. The theory of compression perpendicular to the grain inwood and its application, Dissertation of the University of Tokyo. (inJapanese).
Kato, K., Tsuwa, I., and Koshihara, M., 2008. Shaking table tests oftraditional timber frames including Kumimono Part 1 Experimental outline
and results, Annual Meeting Architectural Institute of Japan. C-1, Structures
III, pp.43-44 (in Japanese).
Tsuwa, I., Kato, K., and Koshihara, M., 2008. Shaking table tests oftraditional timber frames including Kumimono Part 1 Experimental outline
and results, Annual Meeting Architectural Institute of Japan. C-1, Structures
III, pp.45-46 (in Japanese).

172

New Technologies for Urban Safety of Mega Cities in Asia

RESIDUAL DISPLACEMENT PREDICTION
OF R/C BUILDING STRUCTURES
USING EARTHQUAKE RESPONSE SPECTRA
RISA KUWAHARA
Graduate Student, Graduate School of Eng., The University of Tokyo, Japan
kuwarisa@iis.u-tokyo.ac.jp
NORIYUKI TAKAHASHI
Institute of Industrial Science, The University of Tokyo, Japanntaka@iis.u-tokyo.ac.jp
HO CHOI
Institute of Industrial Science, The University of Tokyo, Japan
choiho@iis.u-tokyo.ac.jp
YOSHIAKI NAKANOInstitute of Industrial Science, The University of Tokyo, Japaniisnak@iis.u-tokyo.ac.jp

ABSTRACT
Strong earthquake motions exceeding the current design standard
level have been recorded during recent severe earthquakes in Japan.
Collapsed reinforced concrete building structures are very few because theJapanese building code requires high performance for their seismic safety.
Some of them, however, show moderate or severe damage, and the total costfor their repair often exceeds that of reconstruction. It is, therefore,
important that the building design code ensure not only its seismic safety,
but also its reparability performance. The residual displacement after
earthquakes is one of the most important factors for predicting theirreparability performance. In previous studies, most of researchers estimate
the residual displacement of buildings based on non-linear earthquake
response analyses.
In this paper, a simplified method is proposed to predict the residual
displacement where it is approximated by the point where the line
connecting two displacement peaks in positive and negative domains ofload-deflection curves crosses the abscissa. Considerable prediction errors
are found between predicted displacements in the proposed method andthose directly obtained after non-linear response analyses. The accuracy of
predicted residual displacement is, however, much improved when the 3rd
displacement peak is taken into account in addition to the 1st and 2nd
displacement peaks. The proposed method is further extended and applied
to the conventional capacity spectrum method to predict peak displacements.
It is revealed that the method can successfully predict the residual
displacements and enhance the conventional capacity spectrum method.

173

October 2009, Incheon, Korea

1. INTRODUCTION
Most buildings, which satisfied the current design criteria, survived recent
severe earthquakes in Japan, owing to the high requirement of the seismic
performance to prevent building collapse and human casualties. Somebuilding structures, however, showed damage to some extent after
earthquakes and it cost much more than expected by building owners tohave them repaired. They are concerned with not only direct but also
indirect losses such as business downtime. Performance-based design
therefore should include reparability and functionality of buildings after
earthquakes.
To identify the reparability performance, an effective evaluation index isrequired. In recent studies especially for the precast concrete members, theresidual displacement control is considered an effective method to assure
the reparability performance. In this paper, the residual displacement after
excitations is employed as an index to identify reparability performance ofreinforced concrete structures. A simplified method is proposed to predictthe residual displacement after excitations, and its accuracy is discussed
through comparison with results of non-linear response analyses.
2. PREDICTION OF RESIDUAL DISPLACEMENT WITH PEAKRESPONSE DISPLACEMENTS
2.1 Definition of estimator R of residual displacement
Reinforced concrete structures are idealized with an SDOF system inthis study as shown in Figure 1. Goto et al. (1970) estimate the residual
displacement r after excitations (point A) with the mean value of maximum
response displacements in the positive and negative directions. Kitamura etal. (2009) concludes that the response after the maximum displacement
particularly influences the residual displacement r. In this study, theestimator R of residual displacement r is defined for better predictions
under rational assumptions in the following manner.
The 1st peak P1 in a non-linear earthquake response analysis isdefined as the maximum response point, which is supposed to be found in
the positive domain hereafter, as shown in Figure 1. The 2nd peak P2 isdefined as the maximum response point in the opposite negative domain
after P1, and the 3rd peak P3 is then defined as the 2nd maximum response
point in the opposite positive domain after P2. As shown below, subsequent
peaks P are then defined in the analogous manner described above (Figure 2).

P2i-1: i-th max in the positive domain.
P2i-1: i-th max in the negative domain.
The estimator RN of residual displacement r is then defined as the point174

New Technologies for Urban Safety of Mega Cities in Asia

where a line connecting PN and PN+1 crosses the abscissa as shown in Figure 1.
P1

Force
PN

A

Displacement

Estimator RN
PN+1
P2

Residual displacement rFigure 1: Definition of estimator R of residual displacement
Displacement P
1
P3

P5

P6

Time

P4
P2

Figure 2: Definition of peaks
2.2 Modeling of building structure
The hysteretic rules for building structures are idealized with Takeda
model (Takeda et al., 1970) in the nonlinear earthquake response analyses(Figure 3). The base shear coefficient and the natural period of the structures
are 0.3 and 0.3(s), respectively, in all analyses. A viscous damping factor
proportional to instantaneous stiffness is assumed to be 5% of the critical
damping. The cracking strength is assumed 1/3 of yielding strength and thesecant stiffness at yielding is assumed 30% of the elastic stiffness. The postyielding stiffness is assumed 0.1% of the elastic stiffness. The hysteretic
parameter  for unloading stiffness in Takeda model is 0.5. Three observed
earthquake records are applied for excitation, which are El Centro NS 1940,
Tohoku NS 1978, and JMA Kobe NS 1995. The accelerations are scaled sothat the maximum ductility factor  of the model should reach 1.0, 2.0 and
3.0, respectively. Note that the residual response, rather than the structuralsafety during large inelastic response, is the primary concern in this study,
and the maximum ductility factor  is therefore limited to 3.0 herein.

Residual Displacement Prediction of R/C Building Structures Using Earthquake Response Spectra

175

October 2009, Incheon, Korea

Base shear coefficient

Qy: yielding strengthc : cracking displacement
y : yielding displacement

Qy/mg(=0.3)

0.001K1/3  Qy/mg

Kr= (Qy+Qc)/(y+c)  |max/y|-

0.3K
K

c

y

max

Displacement

Figure 3: Hysteretic model
2.3 Results of analyses
Nine cases consisting of 3 parameters for input earthquake records
and 3 target maximum ductility factors are investigated in this study, and theprediction error R of estimator RN defined in Equation (1) is examined ineach case: R  RN   r  2 y(1)where, RN is the N-th estimator of r (N=1, 2, 3,…),r is the residual
displacement after non-linear response analysis, and y is the yielding
displacement of the model structure.
Figure 4 shows prediction errors R with respect to N. In case of the error R is negligibly small regardless of the value of N in any
earthquake since the values of RN and r are much smaller than y. In casesof and , the error is much larger and does not necessarily decrease
with increase in the value of N. The results found in Figure 4 can be
explained as fallows.
0.2

 =1.0(a) El Centro NS 1940(b) Tohoku NS 1978

 =2.0 =3.0(c) JMA Kobe NS 1995

(RN-r)/2y

0.1
0.0
-0.1
-0.2

1
2
(R1) (R2)

3
(R3)

4
5 1
2
(R4) (R5) (R1) (R2)

3
(R3)

4
5 1
2
(R4) (R5) (R1) (R2)

3
(R3)

4
5
(R4) (R5)N

Figure 4: Prediction error R
Supposing the 1st peak P1 falls within the positive domain and bearing
the definition of estimator RN described in section 2.1 in mind, the values of176

New Technologies for Urban Safety of Mega Cities in Asia

R1 to R5 satisfy the following relation: R2<R1, R2<R3, R4<R3, R4<R5 (cf.
Figure 5). When r is smaller than R2 (Figure 5 left), R2 (N=2) is always abetter estimator of r than R1 (N=1) due to the relation of r <R2<R1. Thus
the prediction is improved with increase in N. On the other hand, when r islarger than R1, R1 (N=1) is a better estimator than R2 (N=2) due to therelation of R2<R1<r. Thus the prediction is not improved with increase in N.
The estimator RN with larger value of N does not necessarily give a better
estimator of r under the values of N equal to around 5 or 6 as investigatedin this study, and the accuracy depends on the relation between RN-1, RN and r.
Figure 6 shows the ratio =|(R2-r)/(R1-r)| to identify a better
estimator, where R2 is a better estimator when  < 1.0 and R1 is a better
estimator when   1.0. As can be found in the figure, a plot in case of
Tohoku NS 1978 (=3) can be better predicted by R1, and this is consistent
with the result found in Figure 4 as enclosed by a dotted line where theprediction error of R2 is larger than that of R1.
P1

Force

P3

r
K2

P3

r

K1
Displacement

r
R1

R2 < R1

P4

R2

P2

P2

R3

R2 < R3

R2

Figure 5: Relationship of R1, R2, R3, and r
Ratio  to identify better estimator
 =|(R2-r)/(R1-r)|

1.2
1.0

Poor prediction with R2
Tohoku NS 1978, =3

0.8
0.6
0.4

 =1.0 =2.0 =3.00.2
0.0Good prediction with R2

r<R2

R2<r<R1

R1<r

Figure 6: Relationship between , R1, R2, and r
2.4 Determination of estimator R
The simplest procedure to predict the residual displacement r is toemploy R1 discussed above. There are, however, some cases where R2 is abetter estimator than R1 as shown in Figures 4 and 6. To identify a better
estimator between R1 and R2, the following procedure is discussed herein.

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October 2009, Incheon, Korea

The difference between R1 and R2 is first examined. As can be foundin Figure 6, the following tendency can be derived.
(1)When r is larger than R1, the ratio  is close to 1.0 and the difference
between R1 and R2 is therefore small.
(2)When r is smaller than R1, the ratio  is generally much smaller than 1.0
and the difference between R1 and R2 is large.
To describe the closeness of R1 and R2 discussed above, an equivalent
stiffness ratio K1/K2 is employed, where KN signifies the equivalent stiffness
connecting peak values PN and PN+1 as shown in Figure 5. Additionally, a
new parameter  defined in Equation (2) is considered to express which of
R1 and R2 is closer to r. When r is located just on the center of R1 and R2, is equal to 0.

   r 

R1  R2  2
2




(2)

y

Figure 7 shows the relationship between  and K1/K2. When K1/K2 issmaller than 1.0,  tends to be negative, which means r is closer to R2. On
the other hand, when K1/K2 is close to 1.0,  tends to distribute around 0 orin the positive domain, and r is therefore closer to R1.
1.00

R1  R2
(a)

K1/K2

0.95

(b)

0.90

 =1.0 =2.0 =3.0

0.85
-0.2

-0.1

r closer to R2

0.0


0.1

R1 < R2
0.2

r closer to R1

Figure 7: Relationship between  and K1/K2
As stated earlier, R1 can be the simplest estimator of r. As can befound in Figure 7, however, R2 can be a better estimator of r in case of
K1/K2 smaller than 0.95. Considering the results above, the following
practical procedure to predict r is proposed.
 r=R1 when K1/K2  0.95 as shown (a) in Figure 7.
 r=R2 when K1/K2< 0.95 as shown (b) in Figure 7.
Figure 8 (1) shows results simply predicted by R1 and Figure 8 (2)shows those obtained by the procedure above. As can be found in the figure,178

New Technologies for Urban Safety of Mega Cities in Asia

the prediction error is, as shown in Figure8 (2), significantly reduced after
considering R2 or the 3rd peak displacement and the proposed procedure canbe an effective tool to predict the residual displacement r.

Residual displacement r [m]0.02 =1.0(1) Predicted with R1 =2.0 =3.0(2) Predicted with R1 or R2
depending on K1/K2

0.01

0.00

-0.01
-0.01

0.00

0.01

Displacement R1 [m]

0.02

-0.01

0.00

0.01

0.02

Displacement R1 or R2 [m]Figure 8: Relationship between r, R1 and R2
3.

PREDICTION OF RESIDUAL DISPLACEMENT
EARTHQUAKE RESPONSE SPECTRAUSINGIn the previous section, a procedure to predict r with R1, R2 and K1/K2 (orP1, P2 and P3) are proposed. If the parameters above can be successfully
predicted from the capacity spectrum method, the proposed procedure canbe practically applicable in the structural design stage.
In the subsequent sections, a new approach to predict R1 and R2 from thecapacity spectrum method is first proposed. It is then combined with theprocedure described in section 2.4 and its applicability is discussed.
3.1 Prediction of peak responses with capacity spectrum method

A new approach to predict peak responses including those after the
maximum using the capacity spectrum method is discussed. The procedureis shown in detail below. Note that the maximum response, i.e., the 1st peak
response, is supposed to be found in the positive domain in this study.
[1]Firstly, the maximum displacement is predicted with the conventional
capacity spectrum method in the positive domain using the structural
capacity curve (i.e., backbone curve) and the demand spectrum (i.e., SA1SD1 curve) as shown point P1* in Figure 9.
Setting i equal to 1 in Equations (3) and (4), the demand SA1-SD1 curve isobtained by multiplying a reduction factor Fh1 and the response spectrumwith a 5% damping factor to consider the effect of hysteretic energy
dissipation due to non-linear response. The equivalent damping factor

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October 2009, Incheon, Korea

heq1 in Equation (3) is evaluated by Equation (4), and the definitions ofdissipated energy W1 * and W1 * are illustrated in Figure 10. The factor
1 in Equation (4) is set 0.8 to predict the 1st peak response considering
the notification No.1457 by the Japanese Ministry of Construction, whichis generally applied in Japan and Midorikawa et al. (2003):
1.5
1  10heqi  0.05
1 Wi *
heq i 
 i
4 Wi *
Fh i 

(3)(4)

where, Wi * is the hysteretic energy dissipation in one cycle, Wi * is theequivalent potential energy, and i is a reduction factor to allow for nonstationary responses to predict Pi*.

Response acceleration SA[SA1-SD1]  Fh1
P1*

P1*
W1 *

-u1

Backbone curve

W1 *

o

u1

-P1*

Response displacement SD

Response displacement SD

Figure 9: Prediction of P1*

Figure10: Definition of W1 * and W1 *[2]Secondly, the 2nd peak is predicted in the negative domain using theconcept analogous with the conventional capacity spectrum method as
employed above.
The employed backbone curve to predict the 2nd peak P2* is shown in
Figure 11, where the reloading curve in the negative displacement
domain after P1* is used. Setting i equal to 2, the SA2-SD2 curve isobtained from the spectrum of 2nd peak defined in section 2.1 and Fh2 inEquations (3) and (4) where the factor 2 is tentatively set 0.8
considering preliminary studies on the ratio of hysteretic energy
dissipation to W2 during non-linear response analyses in chapter 2. The
definitions of W2 * and W2 * are shown in Figure 12 where the unloaded
displacement in the negative domain u2n is assumed to follow theunloading rule of the Takeda model and the distance |o’-u2p| is equal to|o’-u2n| to represent a stationary response. During calculations, the 2nd
peak P2* is initially assumed -P1*, and iterative calculations are
performed until the predicted peak converges.

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New Technologies for Urban Safety of Mega Cities in Asia

= |o’-u2 |p= |o’-u2 |nResponse acceleration SA

P1*

u2p

u2n

y

o’
Employedbackbone
curve

P2*

P 1*

[SA2-SD2]  Fh2

W2 *

W2 *

P2*

Response displacement SD

Response displacement SD

Figure 11: Prediction of P2*

Figure12: Definition of W2 * and W2 *[3]The 3rd peak is evaluated in the positive domain in the analogous manner

described earlier. The employed backbone curve to predict the 3rd peakP3* is shown in Figure 13, where the reloading curve in the positive
displacement domain after P2* is used. Setting i equal to 3, the SA3-SD3
curve is obtained from the spectrum of 3rd peak defined in section 2.1
and Fh3 in Equations (3) and (4) where the factor 3 is tentatively set 1.0
considering preliminary studies as is done for 2. The definitions of W3 *and W3 * are shown in Figure 14 where the unloaded displacement in thepositive domain u3p is assumed to follow the hysteric rule and the
distance |o’-u3p| is equal to |o’-u3n|. During calculations, the 3rd peakP3* is initially assumed P1*, and iterative calculations are performed untilconverged.

Response acceleration SA

Employedbackbonecurve= |o’-u3 |n= |o’-u3 |p[SA3-SD3]  Fh3

P 1*
P3*

-u3n
W3 *

P2*

P 1*
P3*
W3 *

o’

u3p

P 2*

Response displacement SD

Response displacement SD

Figure 13: Prediction of P3*

Figure14: Definition of W3 * and W3 *3.2 Residual displacement predicted through capacity spectrum concept

Peak responses P1*, P2* and P3* are obtained as shown in section 3.1
and then the residual displacement r can be predicted by either R1* or R2*,
which is the point where a line connecting PN* and PN+1* crosses the abscissa.

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October 2009, Incheon, Korea

Residual displacement r [m] (calculated)

Predicted results considering criteria shown in section 2.4 arecompared with those obtained in the non-linear response analyses in Figure
15. As can be found in the figure, the predicted displacement using thecapacity spectrum method compares well with those obtained from the nonlinear response analyses and the proposed method can successfully predictthe residual displacement.
0.02

0.01

0.00

-0.01
-0.01

 =2.0 =3.0

0.00

0.01

0.02

Displacement R1* or R2* [m] (predicted)

Figure 15: Relationship between r, R1*, and R2*
4. CONCLUSION(1)A simplified method is proposed to predict the residual displacement
where it is approximated by the point where the line connecting two
displacement peaks in positive and negative domains of load-deflection
curves crosses the abscissa. Its accuracy is much improved when the 3rd
displacement peak is taken into account in addition to the 1st and 2nd
displacement peaks.
(2)The proposed method above is further extended and applied to theconventional capacity spectrum method to predict peak displacements. It
is revealed that the method can successfully predict the residual
displacements and enhance the conventional capacity spectrum method.
REFERENCES
Goto, H. and Iemura, H., 1970. A study on the Plastic Deformation of Elasto-Plastic
Structures in Strong Earthquakes. Proceedings of Japan Society of Civil Engineers, Vol.
184, pp.57-67 (in Japanese).
Kitamura, H., Nomura, A., Kawasaki, M., Dan, K. and Satou, T., 2009. A Proposal for
Cumulative Damage Evaluation Method for Longevity Life Steel Buildings Considering
Plural Strong Ground Motions. Journal of Structural and Construction Engineering, AIJ,
Vol. 74, No. 642, pp. 1443-1452 (in Japanese).
Takeda, T., Sozen, M. A. and Nielsen, N. N., 1970. Reinforced concrete response to simulated
earthquakes. Journal of the Structural Division, ASCE, Vol.96, No.ST 12, pp. 2557-2573.
Ministry of Construction, 2000. Notification No.1457 by the Japanese Ministry ofConstruction (in Japanese).
Midorikawa, M., Okawa, I., Iiba, M., and Teshigawara, M., 2003. Performance-Based
Seismic Design Code for Building in Japan. Earthquake Engineering and Engineering
Seismology, Vol. 4, No. 1, pp. 15-25.

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PARALLEL SESSION 3

DHAKA CITY: HOT SPOT OR NOT?
MEHEDI AHMED ANSARY
MOHAMMAD SALAHUDDIN RIZVI
Department of Civil Engineering, BUET, Dhaka-1000, Bangladesh
ansary@ce.buet.ac.bd
ABSTRACT
Dhaka is prone to damaging and costly flooding, both from therivers that bound it and from rainfall that generates runoff that is beyond thecapacity of the drains. In less than 20 years, the city has faced three major
floods, each causing huge damage and economic loss. Although thegovernment has taken a number of measures to improve Dhaka's capacity towithstand floods, there is further opportunity. Dhaka is now the world's
eighth largest city. The relationship between climate change and cities iscomplex. City-based activities contribute significant amounts of greenhousegases (GHG) and, simultaneously, are often more vulnerable to the impactsof climate change. The most adverse impacts of climate change are likely to
be in urban areas where people, resources, and infrastructure areconcentrated. Dhaka is the capital of Bangladesh and epicenter of thecurrent urbanization surges. The responsibility of responding to climatechange impacts and consequences will fall on the city government and on its
communities. There is a strong local commitment and organization isrequired to deal with behavior and technological change to reduce carbon
emissions and the disasters that climate changes consequences and regional
threat represent.
Climate change will require concerted actions by local government
and their partners to manage a changing and more invasive environment.
The need to promote changes in technologies, citizen participation andurban growth patterns are equally important parts of the behavior of theurban populations that contribute to global warming and create
vulnerabilities to disasters. Mainstreaming these issues into policy andpractice will lead to a holistic rather than sectoral engagement in climatechange.
The objective of this study is to assess Dhaka city’s human and built
environment characteristics, potential impacts of climate change, andnatural or other hazards. Beyond that, the assessment will also identify
local government prerogatives and authorities that would allow it to takeaction in dealing with potential climate change impacts and natural hazards.
The ultimate determination from the assessment is to identify the areas
which are risky and more vulnerable. This knowledge is then applicable fordefining priority actions that prevent (or “cool down”) the city frombecoming a “Hot Spot.”

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1. INTRODUCTION
Dhaka is situated between latitudes 23°42' and 23°54'N andlongitudes 90°20' and 90°28'E. The city is bounded by the rivers Buriganga
to the south, Turag to the west, Balu to the east, and Tongi Khal to the north.
Figure 1 shows the location of Dhaka city. The city has three distinct
seasons: winter (November-February), dry with temperatures ranging from
10° to 20°C; the pre-monsoon season (March-May), with some rain and hottemperature reaching up to 40°C; and the monsoon (June-October), which isvery wet with temperatures around 30°C. Dhaka experiences about 2,000mm of rain annually, of which about 80% falls during the monsoon.
Dhaka is one of the populous mega city in the world. The Statistical
City Corporation Area of Dhaka has about 7.3 million people within 360
km2 now. It will become fifth largest city by 2030 in terms of population.
Over 40% of the population of Dhaka is poor, who live in slums and fringe
areas and are extremely vulnerable to disaster and climate risks
Urbanization in Dhaka is restricted mostly to the north bank of theriver Buriganga. The four-hundred-year history of Dhaka city can bedivided into five different stages of development: Pre-Mughal period,
Mughal period, British period, Pakistan period, and Bangladesh period.

Figure 1: Location of Dhaka City
Rapid urbanization without considering the geological aspects has broughtsignificant changes in the geo-environment of the city area. Water logging,pollution, changes in the hydrogeological system, localized land subsidence,and building collapse are the hazards associated with these changes in thegeo-environment. Groundwater withdrawal has increased more than 90%
over the last 30 years resulting in groundwater mining and lowering of thewater level by 20 m. Water resources of the city are being polluted by theindiscriminate disposal of untreated industrial and municipal wastes inswamps and natural channels in and around the city.

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New Technologies for Urban Safety of Mega Cities in Asia

In this study, Dhaka city’s human and built environment characteristics havebeen assessed based on a recently published World Bank Primer (2008) on
Reducing Vulnerabilities to Disasters. To assess the Dhaka city’s
characteristics, officials from Dhaka City Corporation, Department ofEnvironment etc. have been interviewed.

2. OBJECTIVE OF THE PRIMER
The Primer is intended to be a tool and an applied knowledge resource for
local governments and their stakeholders to address climate change impacts
and disaster risk management issues in the city. It is not an exhaustive
compilation of thought and practice to prove that climate change is a threat
and does not present recipes for action. Rather it offers principles andexamples of sound practice that a city can adapt to its particular context.
The primer offers illustrative examples of addressing disaster risk
management and climate change as essential components of urban
development and management. The primer reinforces the idea thatsustainable development in urban areas must include disaster risk reduction
and climate change actions to reduce vulnerabilities. Figure 2 illustrates thelinkages between the disaster risk management, climate change, anddevelopment policy.
This primer initiates a learning process that can be carried forward
by local government on the issues of climate change, and the critical
relationship between current urban and financial trends with climate change,
disaster risk management and sustainable development.

Figure 2: Integrating climate change and disaster risk management intodevelopment policies

The main objectives of this study are as follows:a. assess the Dhaka city’s human and built environment characteristics
b. potential impacts of climate change, and natural or other hazards

Dhaka City: Hot Spot or Not?

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October 2009, Incheon, Korea

c. understand the different types of impacts of climate change and natural

disastersd. systematically organize their communities to take proactive actions in
reducing vulnerabilities through mainstreaming resilience
3. HOT SPOT ASSESSMENT
3.1 Completing the City Typology and Risk Charaterization Matrix
After collecting adequate background material, it should complete the city
Typology and Risk Characterization Matrix. Designed to give an overview
of all important issues and activities that could affect the city, the city
Typology and Risk Characterization Matrix is divided into 11 categories of
attributes ( A through K), in six main areas:
City description (A-B)



Governance and management(C-E)
Built environment (F)Political and economic
impacts (G-H)
Natural hazards (I-J)

Climate change impacts (K)Category A identifies the geographic location of the city. This helps in
identification of impacts of climate change and the likely natural hazards
that are of concern of the city.
Category B indicates the size and characteristics of the city area andpopulation. Resident population, floating population, density and growthrate are important indicators of the concentration of problems and their rateof increase over time.
Category C relates to governance structure and hazard management.
Category D establishes the responsibilities for disaster risk management andclimate change management.
Category E focuses on the financial resources of the city.
Category F relates to the city’s built environment.
Category G relates to the political impact of a disaster affecting some cities.
Category H establishes the impact of disasters on the most relevant urban
economic activities of the city.
Category I assesses the threat of natural hazards.
Category J relates to disaster response system and existence of a city’s
emergency response plan.
Category K relates to climate change impact
3.2 Additional Testing for A Hot Spot
A clear link between climate change impacts and the cityvulnerability assessment can be established by completing the figure, inwhich cities evaluate the consequences of specific climate factors such astemperature rise, precipitation change and sea level rise on the main sectors
in the city.

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New Technologies for Urban Safety of Mega Cities in Asia

A benchmark evaluation of risk can also be helpful in motivating thecity to understand where the main gaps and difficulties are in preparing fordisasters and natural hazards. To establish a benchmark evaluation on
Disaster Preparedness and Response in specific sectors for specific natural
hazards, the city officials and their Climate Change Team should assess thelevel of preparedness for each sectors such as industrial, service, financial,
tourism and hospitality etc.
4. WHEN IS A CITY A HOT SPOT?
Being a Hot Spot implies that the city has a high level of vulnerability to
climate change impacts (at least in some sectors, activities, and areas) and is
at high risk of being adversely affected by natural disasters
Based on the completed City Typology and Risk Characterization
Matrix and rating levels, the city government and climate change Teamshould determine their vulnerability assessment that leads to a Hot Spot
categorization : the higher a city's vulnerability, the hotter the city is as a
Hot (Figure 3).

Figure 3: The climate change Hot Spot spectrum
The greater the number of adverse conditions that are satisfied (ratings ofHigh and Medium and Yes responses), the “hotter” the city’s categorization
is as a Hot Spot. The level of “hotness” can be used by the city to prioritize
its activities and to motivate integration of development plans considering
climate change impacts and disaster risk management. Figure 4 shows thelinks among consequences and sectors with potential impacts and climatechange mitigation and adaption options.

Dhaka City: Hot Spot or Not?

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October 2009, Incheon, Korea

Figure 4: Linking consequences and sectors with potential impacts andclimate change mitigation and adaption options
5. THE OUTCOME
According to primer the following outcome has been found for Dhaka
city based on the guidelines recommended in the Primer. Figures 5 (a) to 5(h) show the assessment results for the individual component.

Figure 5(a): Typology and Risk Characterization Matrix: City description
and size characteristics

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 5(b): Typology and Risk Characterization Matrix Governancestructure, city management, and financial resources

Figure 5(c): Typology and Risk Characterization Matrix: Built environment

Figure 5(d): Typology and Risk Characterization Matrix Political andeconomic impacts

Dhaka City: Hot Spot or Not?

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October 2009, Incheon, Korea

Figure 5(e): Typology and Risk Characterization Matrix Hazards and adisaster response system

Figure 5(f): Typology and Risk Characterization Matrix Climate change
impacts

Figure 5 (g): Vulnerability assessment for different consequences of climatechange in urban areas

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 5 (h): Preparedness and response to different natural hazards inurban sectors
From the above data, it can be said that the vulnerability level of Dhaka city
is Medium to High and preparedness and response level to different natural
hazards is Low. So Dhaka can be termed as a “Hot Spot”.

7. RECOMMENDATIONTo remove Dhaka from “Hot Spot” classification, following measures canbe cosidered immediately:
a. City planning must incorporate climate issues
b. Decentralization and pro-poor developmentc. Institutional integration at national, city government, inter agency
and local levels
d. Promote adaptation by building resilience in human, social andnatural systems with greater capacity, awareness and local action in
the current and future climate contexts
e. Adaptation strategies are to be integrated into DRR, urban planning,poverty alleviation
f. Poor need greater resilience with new knowledge, engagement in
adaptation action, resources and technology supports
g. Promotion of Adaptation and mitigation together (energy efficiency,
solar energy and conservation of energy, water, social forestry oncity embankments etc).

8. CONCLUSION
The Primer initiates a learning process for local governments. It
looks at the issues of climate change, the potential consequences of climatechange that can affect cities and the critical relationship between current

Dhaka City: Hot Spot or Not?

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October 2009, Incheon, Korea

urban development and local government financial trends with climatechange, disaster risk management and sustainable development. The primer
recommends a thorough city self assessment and a comprehensive
information base as starting points. It provides sound practices, case studies
and resources that a city can use as follow up to building its programmes forresilience.
Dhaka city is experiencing urbanization at an unexpected rate. The
growth is far beyond the capacity of city governments to provide
infrastructure and basic civic amenities. As a result, Dhaka city is becoming
more vulnerable to the impacts of natural hazards including those due topotential impacts of climate change. The degree of impact from which thecity has been suffering from climate change will depend on the actions andinitiatives local governments take to build a resilient city. City officials needto understand the urban characteristics that make the city susceptible todisaster risk and climate change, such as determining if the city is a Hot
Spot. The city needs to establish and manage a consolidated informationbase that can play a huge part in devising the most appropriate urban
management strategies.

REFERENCES
Alam and Rabbani (2007). Vulnerabilities and responses to climate change
for Dhaka, Environment and Urbanization. Vol. 19: 81-97.
Cities Alliance (2007). Guide to City Development Strategies: Improving
Urban Performance, City Alliance, Washington DC.
Pelling, M. (2006). International Data on Disaster Risks, World Disaster
Report, IFRC, Geneva.
Rahman, A. and DL Mallick (2006). Climate Change Impacts on Cities ofDeveloping Countries: A Case Study on Dhaka.
Schipper, L., and M. Pelling (2006). Disaster Risk, Climate Change andInternational Development: Scope and Challenges to Integration, Disasters
Vol. 30 (1): 19-38.
Van Aalst, M.K. (2006). The Impacts of Climate Change on the Risk of
Natural Disasters, Disasters, Vol. 30(1): 5-18.
World Bank (2007). East Asia Environmental Monitor: Adapting to Climate
Change, World Bank, Washington DC.
World Bank (2008). Climate Resilient Cities: A Primer on Reducing
Vulnerabilities to Disasters, published by the World Bank, Washington, DC.

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PROPOSAL FOR REVIEWING AND
REVISION PROCESS OF DISASTER
MANAGEMENT PLAN IN BANGLADESH-2007 CYCLONE SIDR AS A CASE STUDY1

TAIKI KOU and 2KIMIRO MEGURO

1

Graduate Student, Department of Civil Engineering
The University of Tokyo, Japan
kou@risk-mg.iis.u-tokyo.ac.jp
2
Director/Professor, International Center for Urban Safety Engineering
Institute of Industrial Science, The University of Tokyo, Japan

ABSTRACT
Natural disasters have been causing huge economic and human losses
every year in Bangladesh. Well prepared disaster management plan is an
essential element to mitigate damage and to implement disaster response
operations successfully. Through the experience of several devastating floodand cyclone damages between 1980s and 90s, total disaster management
plan was published and has contributed to decrease the damage. However,after 10 years of its implementation, several controversial points have been
noted these days.
In this paper, the authors discuss future agenda of disastermanagement plan and actual situation in Bangladesh. Firstly, present
situations of disaster management plan called “Standing Orders on
Disaster (SOD)” and actual operations are discussed. The 2007 Cyclone
Sidr is taken as a case study for actual situation analysis. Information on
actual operations was collected by the authors and researchers in
Bangladesh University of Engineering and Technology (BUET) throughfield surveys and briefing papers prepared at that time. Agendas such as
absence of disaster management operations’ total picture, description
amount gap among actors, and obscurity of feasibilities are pointed out
about the current disaster management plan. In addition, agendas such as
not fully achieved situations due to the human/physical limitation,
concentration of operation and scarcity of disaster management operation
records are pointed out about the current disaster operations. Secondly,
based on these agendas, an actually suited disaster management plan modeland a precise disaster management reviewing model are discussed. To
implement disaster management operations exhaustively at disaster
response stage and to make clarify what can or cannot be done at disaster
reviewing process, breakdown structure of disaster management plan is
proposed. To evaluate each operation appropriately and to revise disastermanagement plan for more actually suited disaster management plan,disaster response operation information database is proposed. Finally,
possible usages of these models are discussed. The authors believe these
proposals will contribute to enhancing disaster management plan andincreasing efficiency of disaster management operations.

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1. INTRODUCTION
1.1 Background
Standing Orders on Disaster (SOD), which is equivalent to the basic
plan to implement disaster management operations in Bangladesh, waspublished in 1997. The principal thinking behind the formulation resulted
from the experiences of devastating flood and cyclone damages during the
1980s and 1990s. Before formulating SOD, each disaster management plan(such as flood or cyclone) rarely had uniformity in the plan. To improve
such situation, total disaster management plan; SOD was formulated, which
was adoptable even though the types of disasters are different. The Orders
comprehensively describe total disaster management plan for each of the 38
actors, which are related to disaster management operations by each stage
such as “Normal Times”, ”Alert Stage”, ”Warning Stage”, “Disaster Stage”
and “Rehabilitation Stage”.
However, as it has passed more than 10 years since the Orders were
put into effect, several controversial points have been noted,
 No description of total picture of disaster management operations
 Obscurity of coordination and linkage of operations / information withother agencies
 Planned operations are only listed, and a time axis is not considered.
 Not updated since the publication in 1997
These arguments increase the momentum towards upgrading theOrders into further practical steps these days.

1.2 Purpose of the study
Taking these controversial points into consideration, in this study, we
aim to figure out future agenda of disaster management plan and actual
situation. Next, we aim to propose appropriate countermeasures against
these agendas and set proposal for upgrading disaster management plan.
Firstly, we have analyzed present situation of disaster management
plan and actual situation in Bangladesh. Also, we have analyzed SOD andcompared it to actual operations during and just after the 2007 Cyclone Sidr.
Through the analysis of disaster management plan and actual disastermanagement operations, we have extracted several future agendas for eachplan and actual situation.
Secondly, we have discussed an actually suited disaster management
plan model and a precise disaster management reviewing model from a view

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New Technologies for Urban Safety of Mega Cities in Asia

point of efficient implementation of operations, sufficient accumulation ofdisaster management operation records at disaster stage and comprehensive
reviewing of disaster management operations.
2. ANALYSIS OF PRESENT SITUATION
2.1 Methodology
2.1.1 Operation category analysis
Operation category analysis makes it possible to look overview ofown disaster management operations in the total picture of disastermanagement, and this analysis makes it easier to point out insufficientdescriptions in the SOD. These processes help the SOD to be morecollectively exhaustive. In addition, this analysis makes it possible to figureout other actors implementing cognate disaster management operations.
As it is pointed out in the previous chapter as a controversial point, it
is quite difficult whether the descriptions of disaster management operationsin the SOD exhaustively provide necessary operations (Figure 1 left) since
the absence of disaster management operation’s total picture in the SOD,
which is raised as a controversial point of SOD.
To check up this point, general category which can define total pictureof disaster management operations universally is needed, which has
empirically reviewed and revised to describe for actual suited disastermanagement plan. As one competent category which possibly defines
general disaster management operations, we adopted category of Japanese
Basic Disaster Prevention Plan as a reference, which has reviewed andrevised along with Japanese disaster experiences for about half a century.
(Figure 1 right) For operation category analysis, attribution data which are
the components of category are tagged each description in the SOD (Figure
2 left). And choosing actors and operation category as two axes, each
description in the SOD is plotted on the operation category field (Figure 2
right).

2.1.2 Three dimensional analysis
To visualize amount of disaster management operation descriptions in
the SOD for each phase, we conducted three dimensional analysis.
In order to express and analyze disaster management operations
described in the SOD along with more precise time line, we introduced
relative time axis, which divided three stages into seven phases, which isfrom disaster foreseeing phase to assistance beginning phase (Figure 3).
To visualize the amount of disaster management operation descriptions foreach phase, we added attribution data of relative time axis into each
description in the SOD (Figure 4 left). Choosing actors, time axis andamounts of operations’ description, each actor’s amounts of operations
relative to time is visualized (Figure 4 right).

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October 2009, Incheon, Korea

Disaster Management(DM)Operations’ descriptions
1‐A

4

4‐A

1

1‐B

4

4‐B

1

1‐C

4

4‐C

1

1‐D

4

4‐D

2

2‐A

5

5‐A

2

2‐B

5

5‐B

2

2‐C

5

5‐C

3

3‐A

3

3‐B

3

3‐C

3

3‐D

3

3‐E

No.

・・・

1

No.

:Actor

No.‐X

No.‐X

:Operation

Collecting

Countermeasures
immediately
before thedisaster

Collecting
information,
information,
Ensuring
Ensuring
liaison

Building up
the operation
systemExpansion,
prevention ofdisasterRescue, relief
and medical
treatment

Ensuring andimplementing
emergencytransportation

Evacuation,accommodation

Procurementof reliefmaterials

Health,sanitation,bodytreatment

Maintenanceof social order

Emergency
rehabilitation

Information
propagating

Voluntary aid
acceptanceVictimassistance

Reconstruction
support ofenterpriseliaisonReference: Japan Basic Disaster Prevention Plan

Figure 1: Overview of operation category analysis (1)Figure 2: Overview of operation category analysis (2)196

New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: Overview of three dimensional analysis (1)Descriptions
in SOD
1
1
1
1

1‐A
1‐B
1‐C
1‐D

i
i
iv
v

III

2
2
2

2‐A
2‐B
2‐C

ii
iv
vii

IV

3
3
3
3
3

3‐A
3‐B
3‐C
3‐D
3‐E

i
iii
v
vi
x

No
.

:Actor

No.‐X

I
I
II

I
II

4
4
4
4

4‐A
4‐B
4‐C
4‐D

ii
v
vi
xii

5
5
5

5‐A
5‐B
5‐C

ix
xi
xv

No.‐X

n

IV
V

Actor

・・・

I
III

2
No
.

N

VI

:Operation

1n :Category

Time LineN :Phase
I

II

III

IV

V

VI

VII

Figure 4: Overview of three dimensional analysis (2)2.2 Analysis of present SOD
Using the operation category analysis, we analyze description amount
gap among actors or components of the category in the SOD or operation
feasibilities toward descriptions in the SOD (Figure 5).
From Figure 5, it can be seen that, some plans of disastermanagement operations were fully described to implement comprehensive
disaster management operations, such as Ministry of Home Affairs (MoHA),
Ministry of Shipping (MoS), Ministry of Health and Family Welfare(MoH&FW), Ministry of Local Government (MoLG). During disaster stage,
every actor faces the scarcity of both the artificial and the physical. It isquite important for each actor to describe not only disaster management
operations related to its usual operations but also, disaster particular
operations such as rescue, relief operations excepting the particular
operations which require some authorities or abilities, such as the
distribution of relief aid, rehabilitation of the infrastructure system ormedical relief as a description of SOD.
However, the problem is that “Is it possible or not to implement thewhole operations illustrated in the SOD during the disaster stage whichfaces the crucial scarcity”
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October 2009, Incheon, Korea

If not, the SOD would be an all-round less effective plan. At the stageof comparison with actual disaster management operations, the SOD have to
be checked against whether the SOD was formulated with taking
consideration of that point.

BDRCS
Chairman, Union Parishad
Thana Nirbahi Officer

MoIndustry, MoE,
MoCmmerce etc cannot fully
described the action plans

Deputy Commissioner
Divisional Commissioner
MoE&F
MoPE&MR
MoP&T
MoCommerce
MoE
MoIndustry
MoFA
MoLG
MoSW
MoH&PW

Amounts of description of
Emergency Rehabilitation,
Voluntary Aid Acceptance,
Victim Assistance are
relatively little compared withother categories

MoS
MoC
MoHA
MoD
AFD
MoF&L
MoA
MoFoodMoI

Actor

MoH&FW

BWDB
CPP
MoFDM
IMDMCC

Category

Figure 5: Clarification of disaster management operation fieldof each actor based on operation category analysis

2.3 Analysis of actual disaster management situation-2007 Cyclone Sidr as a case example2.3.1 Follow-up period
This study sets from 13th to 22nd November as a follow-up period ofdisaster management operations led by the government and public
administration of Bangladesh for the following reasons:Situation Report about Cyclone Sidr had been published on 13th
November (15:30, 13th Nov, ‘07). After 22nd November, international
coordination relief operations called “Cluster Approach” which both
described actors and not described actors in SOD committed had started.
This was triggered by the Disaster Emergency Response (DER) Meeting
which government, donor, international organization and NGO participated
in.

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2.3.2 Limited information of disaster management operation
Before starting the analysis, there are some controversial points about
disaster management operation records; partial and limited records ofdisaster management, no detailed description of time and date, amount oftime required or head-count required. These ambiguous points wereconfirmed as possible by the field surveys conducted by the authors and
BUET research members. The results of field surveys were reflected to thisanalysis as much as possible along with the operations defined in SOD.
However, to set an efficient feedback and update system of disastermanagement operation in place, it will be also required to amend how torecord the disaster management data in the future.

2.3.3 Comparison of actual operations and planned operations
by using operation category analysis
Figure 6 shows a comparison result of actual and planned operations
by using operation category analysis (Left: planned, Right: actual). From theresult of analysis and field survey, the following points can be indicated:
1) Disaster management operations were not or could not be
implemented, nor was there a mechanism of informationtransmittance to the upper organization even though the operations
were done
2) Disaster management operations were mainly done within normal
time’s operation fields of each organization
3) Only limited organizations were able to implement measures in theoperation field while several organizations were supposed to
implement the operation.
From the insight of field survey, the reason for point 1) and 2) could
be divided into two aspects. One was a human resource problem, involving
insufficient numbers of public officers or officer’s affliction. The other was
physical problem: insufficient number of motor boats to distribute the reliefmaterials or shortage of budget to keep up a distribution operations.
Related to 2), it could be indicated that there was no room to enlarge
the operation field to disaster-particular operation fields, such as rescue or
relief operations for the problem of the scarcity of human or physicalresource problem.
About 3), in 2007 Cyclone Sidr case, Armed Force Division (AFD)
played a leading role of operations in the field just after the cyclone.
Especially, long-range transportation of relief materials was almost totally
implemented only by AFD.
Besides, the blank areas of the right figure, which means that planned
operations were not done, were substituted by internal/international aid
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October 2009, Incheon, Korea

agencies, NGOs or NPOs.’ relief operations. These situations could be
realized by analyzing not only records but also field surveys.

2.3.4 Comparative analysis of planned and actual disaster managementby three dimensional analysis
Figure 7 is a result of comparison of actual and planned operations(Left: planned, Right: actual). From the result of the analysis, not fully
achieved situation of disaster management operations can be seen as sameas the result of operation category analysis. In addition to that point, fromthis analysis, situation such that a small portion of central organizations
were forced to implement more operations than the Order provisioned isobserved. Such situation was can be seen at the central disaster management
organizations such as Ministry of Food and Disaster Management(MoFDM) or Disaster Management Bureau (DMB). The reasons for theexcess amount of operations, which were confirmed by the field survey,
were the concentration of operations such as coordination operations withseveral donors and UN agencies or operation works at field emergency
operation center (at Barisal).
BDRCS
Chairman, Union Parishad

PlannedThana Nirbahi Officer
Deputy Commissioner

ActualDivisional Commissioner
MoE&F
MoPE&MR
MoP&T
MoCommerce
MoE
MoIndustry
MoFA
MoLG
MoSW
MoH&PW
MoS
MoC
MoHA
MoD

AFD
AFD
MoF&L
MoA
MoFoodMoH&FW
MoI

Category

Actor

BWDB
CPP
MoFDM
IMDMCC

Figure 6: Reviewing process of disaster management operations
by using operation category analysis

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New Technologies for Urban Safety of Mega Cities in Asia

18
16
14
12
10
8
6
4
2
0
CPP Field

18
16
14
12
10
8
6
4
2
0

•Generally, Operations were not fully achieved
along with the Order•Mechanism of information transmittance to theupper office was obscure

BDRCS
BDRCS
bilities of Union Parishad Members
Chairman, Union Parishad
MoLG RDCDLGEDMoLG Local Government Division
MoLG
Fire & Civil Defence
Ansar & Village
BD Police
BDR
MoF&L Directorate of Fisheries Field
MoF&L Directorate of Livestock Field
MoA BADCMoA DG, AED Field
MoFood DG Directore of Food field
MoH&FW DoH Field
BWDB Field(Cyclone)
BWDB Field(Cyclone)
Thana Nirbahi Officer
Thana Nirbahi Officer
DRRO/PIO
Deputy Commissioner
Deputy Commissioner
Divisional Commissioner
MoE&F Department of Enviornment
MoE&F Department of Forest
MoE&F
MoPE&MR Petroleum and Mineral Resources Division
MoPE&MRDG of BD Post office
T&T
MoP&T
Ministry of Commerce
MoE Primary and Mass Edu
MoE
MoIndustry
ERD
MoF Finance Division
MoFA
MoSW
MoH&PW Public Works Directorate
MoH&PW
BIWTA
BIWTC
MoS
MoC BD Roads and Highways Directorate
MoC BD Road Transport
MoC BD Railway Authority
MoHA
BMD
MoD
AFD BAF
AFD Navy
AFD Army
AFD
MoF&L Directorate of Fisheries
MoF&L Directorate of Livestock
MoF&L
MoA DG, AED
MoA
MoFood DG Directore of Food
MoFoodMoH&FW DoH
MoH&FW
Mass Communication
BD Television
Radio BDMoI
BWDB(Cyclone)
CPP
DRR
DMB
MoFDM
IMDMCC•At some field offices,
Human resource and physical problem
prevented from implementing Operations•Some central offices were forced to implement
further operations than planed

Field
officeActualCentralofficePlannedFigure 7: Comparative analysis of planned and actual
disaster management by three dimensional analysis
As pointed out above, insufficient information transmittancemechanism to the upper organization can be observed through the above
analyses. We would like to point out the reason for this insufficiency fromtwo elements, damage information transmittance structure and damage fillin form in Bangladesh, Form-D.
As an ideal situation, damage information transmittance to the central
office would be done by two ways (Figure 8 left); one is Disaster
Management Council route which is the main route of informationtransmittance by using Form-D, and the other is ministry route which
supplement detail attribution information (such as where, who, when thedamage information was gathered) which cannot be contained in Form-D.
However, at the actual situation in 2007 Cyclone Sidr, damage
information gathering were done almost only by the main route; “Form-D
route”. And the function of supplement information transmittance route
could not be observed through the field survey. Therefore, as referred in
Figure 8, at the central control room level and even at the District DMC
level, it was quite difficult to trace which actor did disaster damage survey
and where at the field level. Such situations caused informationtransmittance obscurity and made it difficult to make decisions of relief
operations contingent at the disaster management council.

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October 2009, Incheon, Korea
Info Flow Structure
CDMP
DMIC

Information
Traceability

Damage Information Transmittance Flow

MoFDM
DMB

DRR

National
Damageinfo

Info transmitting
By Form‐D

NumberWho
Where

Central office ofeach Ministry

AffecteAffecteAffectedddPersonPersonPersonDRRO

Form‐D
District office ofeach Ministry

District
Damageinfo

District
DMC

Form‐D
UpazilaDMC

District
Damageinfo

AffecteAffecteAffectedddPersonPersonPersonUpazilaDamageinfo

UpazilaDamageinfo

AffecteAffecteAffectedddPersonPersonPerson12 Fieldoffices ofeach Ministry

Union
DMC

Damageinformation

Damageinformation…

Damageinformation

Damageinformat
ion

Who
Where

UpazilaDamageinfo

AffecteAffecteAffectedddPersonPersonPersonDamageinformation

NumberNumberWho
Where
NumberDamageinformat
ion

…

Who
Where

Figure 8: Information transmittance structure and information traceability

2.3.5 Future agenda of disaster management operations
Comparison of planned and actual operations by using category
analysis and three dimensional analysis enables us to review and evaluate
total picture of disaster management in Bangladesh, which had not been
done sufficiently before.
At the present stage, as we have discussed above, such disastermanagement operations described in the SOD could not be fully achieved, it
is necessary to set priorities on actual disaster management operations under
the human, physical resource and time limitation.
In concrete terms, conducting the following validations enables us toreview actual situation and renew the SOD into more actual suited orders: Figuring out whether each actor could conduct the disastermanagement operations along with the SOD or not, through looking
around the whole situation of disaster management
 About the blank areas which can be seen in right side of Figure 6,
confirming the capacity of implementing disaster management
operations of each actor planned in the Order If there is sufficient capacity, clarifying and ensuring theimplementation framework of the SOD for upcoming disaster. If not,confirming which actor could substitute the operations, and reallocating the operations
 Considering which is adoptable and efficient for the actual situation,
coming to terms with the concentrated situation or seeking alternative
solutions (Ex: concentration on AFD to transform the relief materials)

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New Technologies for Urban Safety of Mega Cities in Asia

3. PROPOSAL FOR ACTUAL SUITED PLAN MODEL
AND REVIWING MODEL
3.1 Discussion for present agenda
for reviewing and revising disaster management plan
Based on disaster management operation records and data of fieldsurvey, we can look into the overview of disaster management operationand point out some action agendas for disaster management operations
through the analyses toward 2007 Cyclone Sidr’s situation. However, thequantity and quality of each disaster management operations or disastermanagement information have not been discussed yet because of the
scarcity of disaster management records which can support to analyze fromthese points of view.
To objectively figure out the entirety of the disaster management
situation, the more precise and structured record of disaster management
operations and reviewing system has to be proposed. At the same time, forpractical use of the disaster management plan at the disaster stage, alsoprecise and easily understandable disaster management plan is required.
From these aspects, we would like to propose some solution
countermeasures toward reviewing and revising process of disastermanagement plan.

3.2 Solution countermeasures
3.2.1 Breakdown structure of disaster management plan
For implementing efficient disaster management operation, disastermanagement plan should be not abstract but more concrete one. For this, it
is quite necessary to establish more precisely broken down structure disastermanagement plan which helps both emergency operation center (EOC) andfield officer to get into action.
Setting Operation category as a highest (most abstract) level, disastermanagement operations are broken down gradually into from large, medium
to small operations, whose levels are similar to actions at field level (Figure9). And the present descriptions’ level in the SOD are not unified (somedescriptions’ level is equivalent to large operation and others’ level isequivalent to medium operation). Establishment of unified and structured
disaster management plan is one of future agenda of present SOD. Further,for sufficient disaster management record accumulation, disastermanagement operation records at disaster stage should be noted along withthat breakdown structure with some attribution data which can record thequantity, quality or information flow of disaster management collectively(Figure 10).
For the record accumulation, disaster management operation
information database should be established, in which several attribution data
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October 2009, Incheon, Korea

closely related to disaster management operations. Although they arecontained such as time information data: start/end time of the operation;organization data: person who committed the operation, resources which areused for the operation; information flow: from whom information whichmake it possible to implement the operation were given, what information
were generated through implementing the operation, and to whom thegenerated information were transmitted; quantity information (operation
amount information): man-hour data, related operations data.
LL Operation

Time Line
Large operation 1

Large operation 1
Middleoperation 1‐1
Small
operation1‐1‐1
S 1‐1‐2

Middle operation 1‐1
Small Operation 1‐1‐1

S 1‐1‐2

M 1‐2

M 1‐2
S 1‐2‐1

S 1‐2‐1

S 1‐2‐2

S 1‐2‐2

S 1‐2‐3

S 1‐2‐3

L2

L2

M 2‐1
M 2‐1‐1

M 2‐1
M 2‐1‐1

M 2‐2

M 2‐2

M 2‐3

M 2‐3

L3

L3

Figure 9: Breakdown structure of disaster management plan

Figure 10: Disaster response operation information database
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New Technologies for Urban Safety of Mega Cities in Asia

3.2.2 Organizational / inter-organizational information
Thus far, we have discussed the contents of operations implemented
by each actor. However, it is quite necessary to clarify own organizational
or inter-organizational information to effectively implement disastermanagement operations or to coordinate relief operations among actors.
According to Yamamoto (1981), organization can be expressed as aformation of four structures (Figure 11); resource structure, decision
making structure, implementing structure and value evaluation structure.
Especially focusing on disaster stage, efficiency of the organization isdefined by the decision making structure and implementing structure.
Further, these structures are regulated by the resource structure.
Resource structure can be expressed by the “Flow Stock”. “FlowStock” is expressed by human resource, which is mainly typified by its
Organograms (person / Position / Decision making authority descriptions)and physical resource amount which is typified by its equipment andmaterial retention list. This “Flow Stock” can make clear the organization’s
resources, which can be applied for disaster management operation.
Decision making structure and implementing structure can be
expressed by diagram. The diagram can be divided into two elements;
information flow diagram and operation flow diagram. Operation flow
diagram makes clear the disaster operation flow, i.e. from whom theoperation is taken over to whom the operation takes over, what operations
will be triggered by the finish of the operation and with whom the operation
has to be implemented. Information flow diagram makes clear the damage
information flow or operation assignment flow; from whom the information
should be acquired to implement own operation, what kind of information
will be generated in own organization by implementing this operation, andto whom this generated information should be transmitted.

Organization Structure
3.3. Possible usageFigureof the 11:
measures

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October 2009, Incheon, Korea

Based on the above solution measures, following discussion would bepossible about disaster management operation reviewing for updating thedisaster management plan.
 Setting appropriate Countermeasures Toward Unfulfilled Operations
As illustrated above at the present situation, we have not had adiscussion foundation of disaster management quality. Using the breakdown
structure disaster management plan for reviewing process, extracting
descriptions of operations and those details from disaster response operation
information database, we would be able to discuss each operation’s quality
more precisely. In other words, we would be able to look into every element,
which compose disaster management operation exhaustively and the criticalreason that prevented from implementing the disaster management (Figure12). This process would be informative to avoid searching abstract reasonsand setting only abstract “all-round less effective” countermeasures for theunfulfilled operations.
 Argument of Operation Quantity and Quantity Equalization
By extracting “man-hour data” from disaster response operation
information database, we would be able to discuss operation quantity ofeach operation and each actor objectively and quantitatively. Based on thisoperation quantity analysis, excess burden of operation or room for
implementing operation would be discussed.
If the “man-hour data” of disaster response operation information
database would be recorded in unified format, it would be able to discussinter-organizational disaster quantities gap. For the actor whose operation
quantity excesses own disaster management capacity, it would be able todiscuss operation quantity equalization countermeasures, i.e. operation
quantity share among disaster management actors toward to handle quantity
imbalances (Figure 13).
 Clarifying Actual Operation / Information Flow
By extracting “start/end time of the operation” from disaster response
operation information database, we would be able to visualize each disastermanagement operation in time axis as Figure 9 shown in. On thisfoundation, we would be able to review disaster management by using Gantt
chart. Further, sorting these operations along with time line, we would be
able to acquire actual disaster management operation flow within the actor.
Summing up each operation flow, we could get inter-organizational disastermanagement operation flow.
As illustrated in
Figure 15 upper, we could trace information which should be
required, generated and transmitted along with operations’ moving ahead.

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New Technologies for Urban Safety of Mega Cities in Asia

Summing up such information in time line, we also could get information
flow.

Figure 12: Concept of operation quality argument

Figure 13: Operation quantity share argument
 Critical Path Clarification and Necessary Information Extracting for
Efficient Disaster Management Operation
Based on the Gantt chart and actual operation flow, we could draw up
PERT operation diagram, i.e. operation flow diagram in which eachbottleneck for implementing operations is clarified (Figure 14). This
diagram clarifies operations on the critical path, which has a possibility todelay whole disaster management operations. This analysis would help eachactor to set countermeasures for these operations on the critical path in

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October 2009, Incheon, Korea

advance and contribute to improving the precision of planned operationflow.
Based on the information flow, by re-assembling disaster management
operations from information flow, we could extract necessary
information to implement disaster management operations along withpassage of time. In other words, who would like to use this information
at which phase of disaster stage would be figured out (Figure 15 lower).This necessary information would be a benchmark
for the operations.

Figure 14: PERT operation diagram
Actor I

RequiredInformation

Time Line

Generated
Information

RequiredInformation

Info A’

Info A’

Info B’

Info B’

Info D

Info D

Info C’

Info C’

Info G’

Info G’
Info H’

Large operation 1
Middle operation 1‐1

Info A
Info B

Small Operation 1‐1‐1

Info CS 1‐1‐2

M 1‐2
Info G

S 1‐2‐1

Info HS 1‐2‐2

Info H’

Info IS 1‐2‐3

Info K’

Info J

Disaster

1 Hour
After

1 Day
After

3 DaysAfter

1 WeekAfter

Info ATime Line
Actor
I

S
1‐1‐1

Actor
III

S
5‐1‐1

Actor
IV

S
#‐#‐#

Actor
X

S
#‐#‐#

Figure 15: Extracting necessary information with passage of time
for implementation of disaster management operation

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New Technologies for Urban Safety of Mega Cities in Asia

4. CONCLUSIONS
We have looked into future agenda of disaster management plan and actual
disaster management operations’ situation. And we have proposed
appropriate countermeasures against these agendas and set proposal for
updating disaster management plan.
Firstly, about present disaster management operations’ situation, it isnecessary to set priorities on actual disaster management operations under
the human, physical resource and time limitation. And it is also necessary toconsider the efficiency validation of operation’s concentrations.
Secondly, for efficient disaster management operation implementing, it isquite necessary to establish more precise and easily understandable disastermanagement plan. For such a plan, setting structurally broken down disastermanagement plan is required. And for efficient disaster management
reviewing, foundation for disaster management operation records
accumulation should be also established. It is hoped that if these proposals
would be put into effect, disaster management plan and reviewing processof actual disaster management operation would be much more enhanced.

ACKNOWLEDGEMENT
The authors would like to express their sincere gratitude for all the
support by Prof. Mehedi Ahmed Ansary and Researcher Afifa Imtiaz, Urban
Safety Engineering Department, BUET for conducting the field surveys.

REFERENCES
Shinya KONDO, 2002. Proposal of Supporting System to Prepare Disaster
Manual for Improvement of Proper Disaster Countermeasures, 20-53.
Yoshiki HIRUMA, Kimiro MEGURO, 2009. Study on Crisis Managementof Organization and Disaster Information Management, Building up
Methodology of Disaster Management Operation, 1-36.
Mehedi Ahmed Ansary, Rubel Das, Afifa Imtlaz, 2008. Role of Logistics
during Cyclone SIDR, BNUS, BUET, USMCA 2008, 249-254.
Yasumasa YAMAMOTO, 1981. Social Scientific Approach for Disaster.
Disaster and Organization. Hirotada Hirose, Japan.
World Bank, 2008. Cyclone Sidr in Bangladesh, World Bank Report, April,
2008.
Government of the People's Republic of Bangladesh, 1999. Standing Orders
on Disaster. Ministry of Food and Disaster Management, Bangladesh.

Proposal for Reviewing and Revising Processof Disaster Management Plan in Bangladesh -2007 Cyclone Sidr As a Case Study-209

DEVELOPMENT OF THE DISASTERINSTANCE MAP INCLUDING HISTORCIALDISASTER INSTANCES DAMAGED BYNATUAL DISASTERS
SEONHWA, CHOI
National Institute Disaster Prevention, Republic of Korea
shchoi333@nema.go.kr

ABSTRACT
Numerous historical records about damage caused by diverse natural
disasters and recoveries from those reinforce us to grow conscious of oursafety and a sense of national disaster management. Although a service
providing information on historical disaster instances in a country is an
essential system among various information systems, there are no systems
providing information on historical disaster instances from the time existing
annals to the present in Korea. We present here a new system called“DiMap”, which provides the information on historical disaster instances
due to natural disasters since the era of the Three States and visualizes thaton a map considering a location at which a disaster instance occurred forhigh usability and high comprehensive faculty by intuition. Through DiMap,
we would like to provide not only the changes of disasters happening in a
specific region by time-series but also damage information, the counterplan of damage, the implication learned through a disaster, and documents
about a disaster instance. In the future, enhancing the contents and userinterface of DiMap by degrees, we will provide various information of adisaster totally.

1. INTRODUCTION
Numerous historical records about damage caused by diverse natural
disasters and recoveries from those reinforce us to grow conscious of oursafety and a sense of national disaster management and are put knowledge
for preventing and preparing disasters to practical use as well by a person in
charge of disaster management.
Although a service providing information on historical disasterinstances in a country is an essential system among various information
systems, there are no systems providing information on historical disasterinstances from the era of the Three States to the present in Korea. In 2008,
the database of the main disaster instances which are built by National
Emergency Management Agency provide several disaster information suchas a damage, a cause of a damage and photographs related to major disasters

211

December 2007, Dhaka, Bangladesh

to a person in charge of disaster management. However, an amount of
information provided by this system is too small and not various, and alsouser interface of this was not designed by a user-friendly method.
We present here a new system called “DiMap”, which provides theinformation on historical disaster instances due to natural disasters since theera of the Three States and visualizes that on a map considering a location atwhich a disaster instance occurred for high usability and highcomprehensive faculty by intuition. By recycling the disaster instance
database constructed previously, by integrating scattered data stored in apersonal computer of a person in charge of disaster management, bycollecting documents related to disasters such as a research report, a reportof on-the-sport investigation, the disaster instance database of DiMap was
made.
Through DiMap, we would like to provide not only the changes ofdisasters happening in a specific region by time-series but also damage
information, the counter-plan of damage, the implication learned through adisaster, and documents about a disaster instance.
In the future, enhancing the contents and user interface of DiMap bydegrees, we will provide the information on various types of disaster and as
well disaster information enlarged by integrating and connecting withrelated disaster information systems. Also we will apply the technology of
Semantic Discovery to DiMap, so that a user will be provided the userspecific data.

2. DEVELOPMENT OF DISASTER INSTANCE MAP
For successful development of DiMap, first of all, we made a prototype of
DiMap as following steps:
a. Sampling data from documents on reporting disasters
b. Define an initial data structure and functions
c. Build a prototype of DiMap
d. Collect and analyze needs of user, feed back to c
By reflecting needs of user repeatedly, a prototype of DiMap was modified
2.1

A target user and contents of DiMap

2.1.1 A target user of DiMap
DiMap will provide information for a person in charge of disastermanagement, a researcher on disaster, and the public by degrees. At first, aperson in charge of disaster management will be serviced, and a service fora researcher on disaster, and the public will be operated by way of showing
an example.

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New Technologies for Urban Safety of Mega Cities in Asia

2.1.2 Contents of DiMap
Contents of DiMap should be inclusive of data from the ancient Korea
to the present. Since the composition of disaster records of the ancient
Korea and those at present about disasters are too different to extract acommon item, we defined contents separately. Table 1 shows the contents
which DiMap services

Times
Three States
GoryeoJoseon

20C and 21C

Table 1: The contents of DiMap.
Contents

the summary of a research report
the original and translation of disaster historical records









damage information due to disasters
the counter-plan of damage
the implications learned through disasters
the on-the-spot pictures before and after recovery
documents about disaster instances
article and report of broadcasting
the disaster history of a specific region by
time-series

DiMap includes disaster instances from the era of the Three States to2008, and contains information of three types of natural disaster such as aheavy rain, an earthquake, and a drought. Additionally, information of seventypes of natural disaster such as a typhoon, a strong wind, a tidal wave, aheavy snow, a steep slope, a lightning, and a forest fire are constructed by
way of showing an example and are planned to expand more. In Figure 1,
we present the plan for a service of DiMap by degrees.

Figure 1: DiMap service by degrees

2.2 The functions of DiMap
For explaining the functions of DiMap, we above all describe userinterface of DiMap divided by four parts (Figure 2): the menu part for
statistical data about disaster instances, the information visualization partDevelopment of the Disaster Instance Map including historical disaster instances
damaged by natural disasters

213

December 2007, Dhaka, Bangladesh

based on a map, the result list of searching, and the input part of conditions
such as a type of disaster, a period, and a region for searching

Figure 2: Four parts of UI of DiMap
2.2.1 Statistical Information about disaster instances
DiMap provides the amount of damage due to a disaster by a district
with color-map, the trend of disasters which happen in a district using agraph.
2.2.2 Visualization of information based on a map
Information of disaster instances are visualized on a map considering
a location at which a disaster instance happen for high usability and highcomprehensive faculty by intuition. We developed DiMap using Open API
functions offered by Google Map for building a base map.
If mouse is over a spot, the list of disaster instances happening in an
adjacent area pops up (Figure 3) and we can select one of disaster instances.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: The list of disaster instance happening in an adjacent area
Also, concise information (Figure 4) and detail information (Figure 5)
on a selected disaster instance can be given. Concise information shows
damage information briefly and provides the on-the-spot pictures before andafter recovery. These pictures are visualized on a location at which adisaster instance happened. If a small picture box is clicked, the enlarged
picture before and after recovery appears. All functions for manipulating a
map are provided.

Figure 4: Concise information: pictures before and after recovery
Development of the Disaster Instance Map including historical disaster instances
damaged by natural disasters

215

December 2007, Dhaka, Bangladesh

To gain more detail information about a disaster instance, click “showthe detail” and then detail information on a selected disaster instance are
given as Figure 5.







damage information due to disasters
the counter-plan of damage
the implication learned through disasters
the on-the-spot pictures before and after recovery
documents about disaster instances
article and report of broadcasting

Figure 5: Detail information
Additionally, DiMap gives the disaster chronicle of a specific region. We
can be given information on a specific area by time-series. For example,

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New Technologies for Urban Safety of Mega Cities in Asia

we can know how many disasters happen or which disasters happen in
our place of residence.

3. CONCLUSION AND FUTURE WORKSIn this paper, we present a new system called “DiMap”, which provides theinformation on historical disaster instances due to natural disasters since theera of the Three States. DiMap visualizes information on a map considering
a location at which a disaster instance happened for high usability and highcomprehensive faculty by intuition.
Through DiMap, we would like to provide not only the disasterchronicle of a specific region by time-series but also damage information,
the counter-plan of damages, the implications of disasters, and documents
about disaster instances. First of all, DiMap services to an officer servant
and then the service of DiMap plans to be expanded for a researcher and the
public by degrees.
In the future, we will enhance the contents and user interface of
DiMap by degrees. Through expanding information on a man-made disasteras well as information on natural disaster, we plan on providing various andabundant information. Disaster information enlarged by integrating andconnecting with related disaster information systems will be included in
DiMap.
Also we will apply the technology of Semantic Discovery to DiMap,
so that a user will be provided the user-specific data.

REFERENCES
Choo, G.S., 1999. Evaluation and Collective Arrangement of Historical
Damaging Earthquakes for the Suggestion of New Korean Seismic Map.
The research report , NIDP, Korea.
The chronicle of Disaster Management, 2009. NEMA, Korea.
Dean Allemang, Jim Hendler, 2008. Semantic Web for the working
ontologist. ELSEVIER.
Ramesh R. Rao, Jon Eisenberg, and Ted Schmitt, 2005. Improving Disaster
Management : The Role of IT in Mitigation, Preparedness, Response, andRecovery, The National Academies Press.

Development of the Disaster Instance Map including historical disaster instances
damaged by natural disasters

217

THE CONCEPT OF U-SAFE CITY ANDSERVICE MODELS IN DISASTER
PREVENTION
Hyun Ju KIM, Hyeong Jun Im
National Institute for Disaster Prevention, Republic of Korea
hjkim5, imhjun@korea.kr

ABSTRACTThe rapid development of information technology has greatly effectedon our life and urban paradigm. In this research, a u-Safe City and a u-Safe
City service are proposed as a national disaster management system. Firstly,a u-Safe City is defined as a city which uses ubiquitous technology tominimize damages from disaster. The vision and goals of u-Safe City arederived from investigating the social change and urban paradigm for thedevelopment of information technology, the condition of disastermanagement within a ubiquitous society and the informative circumstances.
Secondly, a u-Safe City service is defined as a set of ubiquitous activities toprovide disaster information to support decision-making.
u-Safe City service models are classified into 5 detailed services of themonitoring service, the safe management service, the damage estimation
service, the prediction and warning service, and the situation management
service. Based on the definitions in this research, the u-Safe City concept
will be applied to urban developments. This research closes by proposing
the scheme of the systematic and long-term strategy development, thefeasible plan for the promotion and the test-bed projects, and the policy
directions for the u-Safe City promotion.

1

INTRODUCTION

1.1 Background and Purpose
Recently, the rapid advance of information technology has changed
our life and the urban paradigm through integrating the ubiquitous
information service with the urban space. Local governments haveconducted the u-City developments and gradually modified to enhance theregional characteristics and to improve their growth potential.
The purpose of this research is to define the u-Safe City and the uSafe City services for the application on the urban development. It is crucial
to establish the integrated and interrelated u-Safe City service models
among the central and local governments and related organizations for
efficient emergency response and disaster prevention. However, there areconstraints such as discontinuity between the new and the old systems,
discordance between different disaster prevention systems of local219

October 2009, Incheon, Korea

governments. Therefore, it is urgent to develop the national guideline fordisaster prevention in u-City.
1.2 Definition of u-City
Development of ubiquitous city Act, which is the fundamental law on
u-City development in Korea, defines u-City as a city where u-City services
are provided through u-City infrastructures to improve quality of life and todevelop competitive power of city. The Act defines a u-City infrastructure
as an infrastructure which is related to telecommunication or utilized toprovide u-City services, such as RFID, uSN, W-CDMA, WiBro, DMB, etc.
A u-City service is defined by the Act as a service which interactively
collects and provides information of primal urban functions such asadministrative, transport, welfare, environment, disaster prevention, etc.

2. CONCEPT OF u-SAFETY CITY
2.1 Definition of u-City
A u-Safe City is defined as a city uses ubiquitous technology tominimize damages from disaster. In terms of national safe management, uSafe City is practical and strategic plan of "u-Safe Korea" which aims toguarantee safety from disaster in Korean peninsula in the manner ofubiquitous.
2.2 Vision of u-Safety City
The vision of a u-Safe City is "People-oriented Safe City". A u-Safe
City is the model of a safe city where daily life is not interrupted by disaster,and guarantees continuity in urban function. Also, u-Safe city provides
efficient disaster management services. In Korea, many cities experienced
disasters which became serious due to the inconsiderate urban developments,
and they caused a lot of casualties. A u-Safe City values individuals’ lifeand safety in urban developments. The disaster prevention system withubiquitous technology can provide rapid responses, and disaster information
can be managed very efficiently.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 1: Vision and Goal of u-Safe City
There are layers of elements to achieve the vision of the u-Safe city
(Figure 2). Basically, there are u-City infrastructures like ubiquitous Sensor
Networks (uSN), Radio-Frequency IDentification (RFID), etc. Based on uCity infrastructures, u-Safe City services organize another layer. They
provide disaster prevention services to people and governments. Disasterprevention is not a task for a single city, but cities in the co-operational
system. In many cases, even all national power and resources need to be
assigned quickly and systematically, which can be done effectively byconnections among u-Safe Cities.

Figure 2: Target System of u-Safe City

3. u-SAFE CITY SERVICE
A u-City service can be defined as a set of ubiquitous activities to collectand process information, and provide a proper result for a certain purpose.
In u-Safe City, a certain purpose is the disaster prevention, and theinformation is about disasters. Therefore, u-Safe City service can be defined
as a set of ubiquitous activities to provide disaster information to support
decision-making of disaster management system.

The Concept of u-Safe City and Service Models in Disaster Prevention221

October 2009, Incheon, Korea

The model for u-Safe City services is classified into 5 detailed
services. They are the monitoring service, the safety management service,
the damage estimation service, the prediction and warning service, and thesituation management service. Figure 3 shows the examples of service
applications.
Figure 4 is a conceptual master plan of u-Safe City services.
Emergency Operations Center (EOC) is the main body of u-Safe City
services. EOC operates the monitoring service as well as the damage
estimate service and the safety management service. When there is a
symptom of disaster, EOC delivers warning messages to local government,
the individuals in the vulnerable area and the relative organizations. EOC
also delivers disaster information to support the situation management.

Figure 3: u-Safe City Services (NIDP, 2008)

Figure 4: Concept of u-Safe City Service

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 5 shows an example of the u-Safe City flood mitigation service.
First of all, there is a set of monitoring services on the spots. The sensors are
installed on the riverside to monitor the flood control facilities. The sensors
in the inner city collect information of the urban underground space and thelow level area. Hydrological and meteorological information are alsocollected and directly sent to EOC by cable or wireless networks. EOC has
data-base servers, web servers and operational servers. Informationdelivered to EOC are stored in the database servers and released to public by
web servers. When EOC catches abnormal symptoms, EOC immediately
responds and recovers remotely or manually. EOC also conducts thedamage estimation based on the flood hazard map. Then, they develop
preparation scheme such as flood response guidelines and co-operational
system with the relative organizations. If flood outbreaks and is caught by
sensors, the information will be sent to the EOC operators. The information
also will be sent to the individuals on the low level area to help theirevacuation on occasion. In case of road inundation, EOC directs vehicle
bypassing by controlling the traffic signal or variable message sign (VMS).
EOC Servers exchange real-time information with relative organizations
and neighborhood cities for cooperation and their preparation. After flood,
sensors collect the damage information to re-assign the vulnerable area andconduct recovery projects. Pre and post disaster information is collected insystematic and automatic manners, and reported to the central government
for national aid.

Figure 5: Concept of u-Safe City Flood Mitigation Services
Figure 6 shows an example of u-Safe City fire prevention service.
There are three objects in the fire prevention service. They are the district
office which operates EOC, the field manager, and the fire department. The
sensors at the target site collect the site information of flame, movement,
smoke, and temperature to send to EOC which operates DB server, WEB
server, SMS server, and control server. The EOC processes information
The Concept of u-Safe City and Service Models in Disaster Prevention223

October 2009, Incheon, Korea

from the site and operates the services such as the damage estimation andthe real-time surveillance. If there is a signal of fire at the target site, EOC
makes a request of dispatch to the fire department

Figure 6: Concept of u-Safe City Fire Prevention Services

4. CONCLUSIONS
A u-Safe City is a city which uses ubiquitous technology to minimize
damages from disaster. The goal and the vision of a u-Safe City satisfies thegoals of the national ubiquitous projects such as the e-government projectby Ministry of Public Administration and Security (MOPAS), the nationalsafety management information project by NEMA and the u-Safe Korea
project of NIDP. Complement and linkage with the projects above arenecessary as well as comprehensive planning and strategic approach on
disaster prevention system, while the platforms for u-Safe City system and
EOC with ubiquitous technology are necessary for u-Safe City service
operation.
Many local governments are interested in u-Safe City, on the other
hand, they have distinct condition on u-City infrastructure, disastercharacteristics, and disaster management system. Accordingly, it isimportant to promote u-Safe City projects on a certain type of disaster, andto gradually procure the requirements for u-Safe City and u-Safe City
services.
There are 3 elements on u-Safe City promotion scheme. Firstly,
Systematic and long-term strategy development is necessary for effective
promotion and synergy effect. Further researches are recommended for theelaboration of u-Safe City services based on the demand analysis and theverification to allow for the trend of the information technology and thechanges in the ubiquitous environments. Secondly, the feasible promotion
plans as well as the test-bed projects based on the super ordinate

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New Technologies for Urban Safety of Mega Cities in Asia

development plan and the related projects are important. The model projectsof governments are able to verify its adequacy and to be applied to the newurban developments. Finally, the policy direction needs to be formulated forinvestment and cooperation among governments, private companies,
academy, and research institutes.

REFERENCES
Kang, Yejin, 2006, A study on paradigm shifts of disaster management andthe betterment of urban disaster management system, Ajou Univ.
Busan, 2007a, A report for the establishment of strategy regarding Busan uSafe City model
Busan, 2007b, A study on u-Busan urban disaster prevention system
Jeremy Morley, 2003, MasterMap in Academia-Experiences at UCL,
University College London
Kim, Sang Bong, Cho, Woo Jin, 2007, A Study on the Development andApplication of 3Dimensional Spatial Information of Virtual City Using
Digital Photogrammetry, Geodesy, Photogrammetry, and Cartography,
Korean Society of Surveying
Korea Institute of Construction & Transportation Technology Evaluation
and Planning, 2006, Construction of the 3D Virtual Land Information andDevelopment of its Application
Lee, Seong-Kil, Cho, Jung-Rak, Kim, Jung-Jae, 2008, Ubiquitous city tolead u-City project
Masahiko Murata, 2004, 3D-GIS Application for Urban Planning based on
3D City Model, ESRI International User Conference 2004
MIC, 2006, u-Korea master plan to realize the first leading ubiquitous
society
NIA, 2005a, The development history of information policy in Korea
NIA, 2005b, A study on the core applied technology and standardization
NIDP, 2008a, Introduction of principles for disaster prevention planning in
u-CityNIDP, 2008b, Development of the standard model for ubiquitous disasterprevention City
NIDP, 2008c, A study on the construction for the u-Safe Korea system
Park, Inhye․ Jun Chulmin․ Lee Jiyeong, 2008, GIS-based Fire Evacuation
Simulation using CA Model, Geographic Information System Association of
Korea
P. Frederiksen. J, Grum. L.T, Joergensen, 2006, Strategies for Updating a
National 3-D Topographic Database and Related Geoinformation, National
Survey and Cadastre, Seoul Development Institute, A Study on developmentof Seoul Virtual City using 3D GIS
Shin, Seong-Beom, 2006, A comparative study on Korea and Japan for
Ubiquitous IT strategy, Tong-Myong Univ.
Shim, Jae-Kang, 2002, A study on integrated emergency management andemergency information system - the seoul metropolitan emergency
operation center, Univ. of Seoul
URISA, 2006, 3D Geospatial, 2006 Workshop
The Concept of u-Safe City and Service Models in Disaster Prevention

225

METHOD FOR PROBABILISTICDISASTER RISK EVALUATION USINGRISK CURVE ANALYSIS
PARK, SOSOON
National Institute for Disaster Prevention,
sspark@korea71.kr

ABSTRACT
Recently, damage magnitude of disaster is sharply increasing but its
occurrences and damage scales are so uncertain that it is hard to constructa reasonable response, mitigation plan and its infrastructures. Therefore,
the needs for an advanced risk management technique based on aprobabilistic and stochastic risk evaluation are increased. In this study,
these evaluation methods were investigated and an advanced disaster risk
evaluation method, which is based on the probabilistic or stochastic risk
assessment theory and also on a quantitative evaluation technique by risk
curve analysis, was suggested. With this method, each risks of humaninduced disaster for recent 10 years were evaluated respectively andcompared. Through the consilience of the traditional risk assessment
methods and this method, a probabilistic risk estimation technique for theuncertainty of future disaster's damage could support for a reasonabledecision making on disaster damage mitigation.
1. INTRODUCTION
Various disaster management policies were developed in Korea after
NEMA was started 5 years ago. Disaster damage occurrence status forrecent years was over-viewed and it is clear that the national disaster rateand its total damage were reduced in a large scale compared to those ofhuman-induced disaster (National Institute for Disaster Prevention, 2008).
Therefore, the safety and damage loss reducing technology for humaninduced disaster mitigation was started to development recently. For thereasonable and effective disaster mitigation plan, disaster’s damage risk
must be evaluated clearly as like risky factor’s distribution over aroundareas and their occurrence probabilities and severities also. If prediction for
the future’s risk is possible, it is so much the better for decision making. But
it is very difficult to predict the future’s risk .
Therefore, various quantitative disaster risk indexes of human-induced
disaster, which is based on the risk-based analysis method dealing withstatistics technique and probabilistic risk assessment using risk curve, wasinvestigated in this research. From the results, some quantitative disasterrisk evaluation functions are suggested, which is able to evaluate

227

October 2009, Incheon, Korea

quantitatively disaster risk without concern of area neither dimension nor
disaster’s type. Through the results of this research, surveying theoccurrence states of domestic human-induced disaster as quantitative
disaster risk’s change behavior and its characteristics could be possible. And
the safety states of future risk level could be exactly estimated relatively inrange of trustworthy if the system structure of the industry facilities and its
distribution/infrastructures of nation/city/region were not changed in a large
scale.

2. RISK MAP AND RISK CURVE
2.1 Definition of risk and risk map
According to the Kaplan and Garrick, risk R(x) is the accident
scenario with event series of disaster which was caused by troublesome
event/factors and expanded to incident in a construction, local society orsystem of industry. From the definition of risk, a general concept figure of
the observed data, which is the discrete probability of event and time series
data during monitoring period, is called risk map. Risk map can be
expressed by triple set of T (i ) , S (i ) and X (i ) . Statistical risk values of timeseries data in risk map is given by Equation 1.
RiskMap =< S (i ), p (i ), x(i ), t (i ) >[ x(i ), t (1)] < [ x(2), t (2)] < ⋅ ⋅ ⋅ < [ x(i ), t (i )] < ⋅ ⋅ ⋅ < [ x( N 0 ), t ( N 0 )](1)

i = 1,2,3,⋅ ⋅ ⋅, N 0

Here, accidents caused during monitoring period T can be expressed
as a disaster risk map shown at Figure 1. And an accident and its damage
scale were resulted in accordance with its scenario gotten over a local
system or area. Then, some scenario list can be elicited from the disasterrisk map and these scenarios were sorted as a sequential list in inverse orderof the damage magnitude from maximum to minimum. In Table 1, N 0 setsof accident’s scenario S (k ) , its each occurrence probability P (i ) anddamage scale X (k ) were given, which is called scenario list. A scenario listof exceedance cumulated probability as like Table 1 can be made bycalculating the exceedance cumulated probability for each threshold ofdamage scale. When a total count number of accident scenario causing
disaster in a target system is N 0 , accident scenario is S (k ) , its eachoccurrence probability is P (k ) and threshold of damage scale for accountis X (k ) , a triplet set which was composed with these three factors is definedas the risk itself in a target system, which is shown in Equation 2.
Risk =< S ( k ), p ( k ), X ( k ) >,X (1) = X Min < ⋅ ⋅ ⋅ < X ( N 0 − 1) < X ( N 0 ) = X Max , k = 1,2,3,⋅ ⋅ ⋅, N 0

228

(2)

New Technologies for Urban Safety of Mega Cities in Asia

Magnitudeof damageAccident i
Accident 2

Accident 1

Accident (i+1)

Accident N0

Accident 3

· ···

h

·· ··

Accident (N0 -1)

TTime, th : threshold value for significant event

Figure 1: Disaster risk map for observation period T
Table 1 : Scenario list and exceedance cumulated probability
Scenario

Damagescale

Probability
P = F / N0

Exceedance cumulated probability,

SN 0

X ( N 0 ) = X Max

PN 0

Pexcd ( N 0 ) = P( N 0 )S N 0 −1

X ( N 0 − 1)

PN 0 −1

Pexcd ( N 0−1) = P( N 0−1) + Pexcd ( N 0 )

·

Sk

·

Xk
·

Pexcd = Fexcd / N 0·

Pexcd ( k ) = Pk + Pexcd ( k +1)

Pk
·

·

·

·

S2

X2

P2

Pexcd ( 2 ) = P( 2 ) + Pexcd (3)S1

X 1 = X Min

P1

Pexcd (1) = P(1) + Pexcd ( 2 )2.2 Statistic disaster analysis and the disaster risk curve function

If each value of damage scale X and its exceedance cumulated
probability Y are plotted respectively, then a disaster risk curve during
monitoring period T can be expressed as a stairs-type function with thediscrete damage magnitude which was shown at Figure 2. From statisticalrisk value of time series data, risk map was represented in Equation 1 andFigure 1 in details. If the damage scale (probability variable, X ) has
continuous values, the disaster risk curve can be expressed as a curve with acontinuous line. It can be called as a disaster damage characteristic curve as
well. Here, let the probability variable of damage scale as X and let the
cumulated frequency of each scenario’s occurrence probabilities of that X
exceeds h as P(h) . Then, X and P(h) at the X can be represented as shownin Figure 2. CDF is a exceedance cumulative distribution function and therelationship between X and P(h) is given as follow (equation 3):

Fexcd (hi ) = CDF [ X ≥ hi ] or Pexcd (hi ) = Pr[ X ≥ hi ], i = 1,2,3,L, M(3)

If the discrete time series data of a finite number of accident
occurrences are arranged as N 0 accidents from the Figure 1, then the

Method for Probabilistic Disaster Risk Evaluation Using Risk Curve Analysis229

October 2009, Incheon, Korea

relationship between X and P(h) can be expressed in the followings(equation 4):∞

Fexcd (h) = ∫ C ( x)dx ∝ h − Ds , Ds > 1(4)h∴ Pexcd (h) = Fexcd (h) / N 0 = h− Ds, Ds = Ds − 1 > 0This type of distribution function is called Pareto type distribution that
depends on Ds dimensional fractal distribution with self-similarity and only
the inverse power law function satisfies the fractal distribution (Takayasu
Hideki, 1991). And this distribution is the disaster risk curve if values
log h are plotted at X-axis and log P(h) values at Y-axis. Disaster riskfunction of Equation 4 means that the relationship between damage
magnitude and its exceedance cumulative probability can be evaluated by
the dimensional fractal distribution with self-similarity.
P

Log[R(X′)]

discretefunction
계단형함수

P1

1
리스크곡선
risk
curve

P2

D2’
D1’
PN
X1

X2

(a) Risk curve

XN

X

Log(X′+1) , X′ +1>0(b) Normalized risk curve

Figure 2: Concepts of stairs-type disaster risk function, risk curve andnormalized risk curve
Here, if statistic disaster analysis was conducted within a same grouphaving a fixed total count number of disaster, and if the probability variable
X has continuous value, P(h) is able to represent as an exceedance
probability. That is expressed as an exceedance probability distributionfunction (PDF). Therefore, Fexcd (h) and Pexcd (h) are able to consider as anequivalent value.
In Figure 2, the risk curve plotting cannot be entirely described by alog-log linear relation even though the results in the range of high damage
magnitude are well fitted. Thus, in order to represent the frequency-damage
magnitude relation in a log-log linear type over the entire distribution region,a certain location parameter, say γ , was introduced. In other words, the timeseries data in Figure 1 can be considered to be on a base line γ . Then thedata is rearranged under h + γ (= h' ) in the damage magnitude range value
instead of h which was used as threshold value in Figure 1. Then thefunction of damage magnitude and probability at that damage will be
represented as follows (equation 5 and equation 6):

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New Technologies for Urban Safety of Mega Cities in Asia

Fexcd (h) ∝ (h + r ) − Ds ' , Ds' = Ds − 1 > 0(5)Fexcd (h) / N 0 = [(h / r ) + 1]− D ' , h ≥ 0(6)R(h) = Fexcd (h) / N 0 = [(h / r ) + 1]− D ' , h ≥ 0(7)This equation can also be considered as a same kind of Pareto type
Fractal distribution as represented in Equation 4. The location parameter γ
is estimated by the least square method to the assumed regression risk curve.
In selection of introducing γ , Equation 5 depends on the shape of theoriginal risk curve. From these conclusions, a location parameter γ would
be a meaningful parameter because it is not only a location parameter thatapproximates a linear function, but also has a specific value particular forthe subject accident data group. As given in Figure 2, damage magnitudes
due to those accidents depend on an inverse power law function of theEquation 5 in case of location parameter of γ was introduced.
Here, R(h) is referred as "upper exceedance cumulated probability
distribution function". The parameter of γ in Equation 6 and Equation 7 is alocation parameter of Pareto type distribution function in a statisticalmeaning as mentioned also. Here, let introduce a new concepts of damage
scale variable as X ' = h / γ then X ' can be defined as a normalized damage
scale variable which has no dimension. Hence, the exceedance probability
distribution function PN ( x) and the upper exceedance probability
distribution function RN ( x) of X ' are given as follows:
PN ( x) = Pr( X ' < x) = 1 − (1 + x) − D '(8)

RN ( x) = Rn ( x) = Pr( X ' ≥ x) = (1 + x) − D '(9)At the Equation 9, RN ( x) is referred as a normalized risk curve. This
normalized risk curve can be represented on a log-log scale plotted graphbased on the relation between RN ( x) and 1 + x for overall x value as alinear straight curve as shown in Figure 2. As like this, the magnitude ofdamage in this risk curve can be scaled by the normalized unit of X ' without
concerning of damage’s type or its unit. It is the reason why the various
kinds of disasters can be expressed, evaluated and compared quantitatively
each other even though disaster kind or their damage type is different.

3. SUGGESTION AND COMMENTARY OF QUANTITATIVEDISASTER RISK INDICATOR INDEX

From the disaster risk curve, various indicator indexes to evaluate thedisaster risk and disaster risk parameter are introduced.

Method for Probabilistic Disaster Risk Evaluation Using Risk Curve Analysis

231

October 2009, Incheon, Korea

r2

r4
r3

ri

r5 r6 ri

(Area 1 or Area 2)

1

Area 1Px(Area2) = 20 %Area 2

0.1
Px(Area1) = 10.2 %At Loss level : XP(x)(Area) =60
D(Area 1) =6

D(Area 2) = 5.7

0.01
0.01

XP(x)=60

0.1

1

10

100

1000

Loss
damage) ofyears,MHRp(or(Momentary
AEaccident
activity),for
hit10
rate
/ hit·hX-1

Exceedance cumulative probability

r1

Exceedance cumulative probability / -pX1) | D | and | D |−1
They are come from the slope value of tail part in the disaster risk
curve, which is a territory where the reverse Pareto function (power law
function) is formed. It can be expressed as D = − log F ( x) / log( x) and it’s akind of the dimensional fractal distribution with self-similarity.
1-0.6116y = 7.2766x2

Pexcd(x0.3)

R = 0.9724

Pexcd(x0.2)
0.1

Pexcd(x0.1)
Pexcd(x0.01)
0.01

X0.1
0.001
0.00001

0.001

0.1

10

X0.3

1000

X0.2

X0.01
10000010000000

6

Magntitude of damage cost by fire accident, X [10 won],'90 ~ '06, Korea

Figure 3: Concepts of local disaster risk analysis and comparison between twoareas and deducting disaster risk monitoring parameters from risk curveThis parameter | D | can be employed as a safety index whichcharacterizing the relationship between the damage scale and its occurrence
probability (frequency) in a certain system. This is a parameter thatindicates the functional ability index or a safety yardstick of fail-safeorganizations statistically. Here, | D |−1 can be used as a disaster risk
intensity factor because it represents the ratio of increased damage scale perunit accident or event, which can be understood from the function of | D | .
2) < X k > and < X Nk > , < X Max > and < X NMax >They are the statistical damage magnitude and normalized damage
magnitude at a focused occurrence probability range, which can be referredfrom Figure 3. Damage magnitude in evaluating disaster risk is an important
index. The value of k is the exceedance occurrence probability with thethreshold damage level to be monitored or controlled. These values can be
set by the decision maker to manage the disaster risk in a range ofacceptable risk level according to the status of the society’s needs for safety.
For example as like < X 0.03 > , < X 0.1 > , < X 0.2 > and < X 0.3 > , which meansa value of statistical damage magnitude at a monitoring risk levelprobability 3%, 10%, 20%, 30% respectively. Values of< X Max > and < X NMax > are also very important indexes. They are themagnitude of maximum damage, which can be used for maximum risk
degree by disaster. And the scenario of the accident can be the worst
scenario at the same type of disaster.

4. SUGGESTION OF
EVALUATION METHODQUANTITATIVEDISASTER

RISK

4.1 Quantitative disaster risk function using risk curve analysis

232

New Technologies for Urban Safety of Mega Cities in Asia

As a disaster risk evaluation index, | D |−1 , < X k > , < X Nk > , P( X k ) ,P( X N ) could be useful. Using these indexes, disaster risk function can be
represented in Equation 10. The meaning of these indexes are examined andexplained before. If disaster risks among different kinds of disaster that
happened within the same area and same periods are compared, thepopulation characteristic of their group is same. Therefore, the regional
disaster risk depends on just Function [ Xp(i ), | D |, p (i )] and the comparisonof various type of disaster is possible with only Xp(i ) / | D | . Then thedisaster risk function can be given as follow, which has the same form withlocal disaster risk evaluation function of a'Albe (Emergency Management
Agency, 2008).
DisasterRisk ∝ Function{| D |−1 , < Xp (i ) >, < p (i ) >} =< X a > × p (< X a >)|D|

X × p ( X Max )MaximunDisasterRisk = Max
|D|

(10)

4.2 Comparison of human-induced disaster’s risk

It has been possible to quantitatively compare the degree of disasterrisk according to each human-induced disaster through the using risk curve
analysis method and disaster risk function of a'Albe, which utilizes the risk
curves. Further, it has been possible to secure the objectivity and theefficiency for priority decision about disaster countermeasures.
1000

Normalized exceedance cumulative
probability

Exceedance cumulative probabilty1

0.1
Collapse('96-'05)
Fire accident ('96-'05)
Wild fire('96-'05)

0.01

Ship accident('96-'05)
Explosion('96-'05)* Wild fire [ha]0.001
0.00001

Explosion('96-'05)
Fire accident ('96-'05)
Collapse('96-'05)

10

Ship accident('96-'05)
Wild fire('96-'05)

0.1

0.001

0.00001
1

0.001
0.1
106
1000
Magnitude of damage cost, X [10 won], Korea

100000

10

100

1000

10000

1000001000000 10000000

Unified magnitude of damage, damages,
X'+1, '96-'05, Korea(a) Damage cost(b) The death
Figure 4: Risk curves and normalized ones of human-induced disasters
At 3% upper exceedance cumulated probability of damage cost, it was
Explosion that showed the highest risk level with the highest risk intensity
factor. And Explosion and Collapse at 10% and 20% showed the highest
risk level with the highest risk intensity factor respectively. In details of
10% upper exceedance cumulated probability of damage cost, risk level ofExplosion was the highest and Collapse showed the lowest risk level. Also,
Explosion was 1.7 times of Collapse’s risk, Ship accident was 1.4 times, andFire accident was 1.2 times. In terms of fatality risk level, Ship accident
showed the lowest level and Fire accident showed the highest risk level
which was 11.4 times of Ship accident’s risk. While Collapse was 2.4 times
and Explosion was 1.2 times of it. In a same way, risks of each disaster were

Method for Probabilistic Disaster Risk Evaluation Using Risk Curve Analysis

233

October 2009, Incheon, Korea

analyzed at 3% and 20% upper exceedance cumulated probability also. But
the results of at the 10% upper exceedance cumulated probability wereshown as representatives.
As like this, it is possible to utilize the damage magnitude regarding
each exceeding cumulative probability as a disaster risk index. As anotherusage of disaster risk curve, if an accident “A” was happened and its
damage magnitude was X = 60 . Here, the risk curve was given of the area as
Figure 3 (left), then it is possible to understand that the accident A’s risk
degree is in range of the worst upper 10% at Area 1 and the worst upper
20% at Area 2. From this, decision maker can rearrange the risk
management policy and method depends on the areas.

Figure 5: Quantitative disaster risks for the last 10 years

5. CONCLUSION

It is still difficult to apply existing techniques to the whole region of city or
nationally with conventional risk assessment. However, this research was
not aimed to examination of complicated physical characteristics of theaccident, but aims to the simple and quantitative evaluation method ofdisaster risk including the statistical probability and damage scales. For that,lots of accidents and just simple emergency information as like damage
magnitude, accident’ area and date and disaster type that happed over awhole area were used. It is certain that it is possible to evaluate the disasterrisk of whole regions easily and quantitatively from the results. Furthermore,
the estimated results by risk curves showed that the magnitude of damage
and risk directly depends on their probability. Therefore, it is easy for thedecision maker to understand the total risk states (or safety state) due todisasters over a region of district or nation.
In fact, the quantitative disaster risk index and the disaster risk evaluation
technique, utilizing disaster risk curve in this paper, has shown high level ofconfidence regarding large scale disaster. Also, it has been possible toquantitatively compare and analyze the observatory frequency according todisaster type/region/facility, regardless of damage types.
From these conclusion, disaster risk evaluation technique and related
prognosis technique by risk curve method, which is trustworthy andquantitative, may be able to play an important role in producing information
for an effective decision making in the field of emergency management in
Korea.

234

New Technologies for Urban Safety of Mega Cities in Asia

REFERENCES

Hanayasu, S. and Sekine, K., 2003. Statistical damage modeling andanalysis of industrial accidents and its application to industrial safety
problems, Applications of Statistics and Probability in Civil Engineering,
San Francisco, California, USA, July 6-9, pp.792 ~ pp.799.
Wackerly, D.D., Mendenhall, W. and Scheaffer, R.L., 1996. Mathematical
Statistics with Applications (Fifth Edition), Duxbury.
National Emergency Management Agency, 2008. Disaster and Safety
Management LAW, Homepage of Ministry of Legislation.
National Institute for Disaster Prevention, 2008. The Major Outcomes ofDisaster Prevention Researches in 2008, pp.259 ~ pp.276
Hideki T., 1991. Fractals in Physical Sciences, Manchester University Press,
New York, pp. 1 ~ pp. 58

Method for Probabilistic Disaster Risk Evaluation Using Risk Curve Analysis

235

PARALLEL SESSION 4FAILURES AND SUCCESSES OF
JAPAN’S EARTHQUAKEENGINEERINGTSUNEO KATAYAMA
Professor, Tokyo Denki University, Japankatayama@cck.dendai.ac.jp

ABSTRACT
People often say that Japan is one of the most advanced countries in
the field of earthquake engineering. It may be true in a sense. But, because
Japan is located in one of the most earthquake prone areas on earth, we
also made so many failures in the past. We did learn from failures, but at
the same time some of our successes were followed by different types offailures.

1. UNTIL THE KOBE EARTHQUAKE
1.1 Our Earlier Failures
Probably we made our first major failures near the end of the 19th
century. In 1891, a disastrous earthquake took place in central Japan and in1894 the Tokyo area was strongly shaken by a medium-sized earthquake.
Japan was eagerly importing the western culture and science during thisperiod, but the damage caused by these earthquakes showed that the simple
import was inadequate and pointed to the importance of establishing somestandards for earthquake resistant structures.
Although a written form of earthquake-resistant construction
requirements was not made available immediately following those events,
younger engineers in Japan adopted a commonsense engineering approach.
The 1906 San Francisco earthquake gave impetus to the problem. It was
proposed that earthquake-resistant structures could be built by assuming
lateral force proportional to the structure’s weight. A coefficient k = a/G
was to be laterally multiplied to the weight of a structure, where a is theacceleration assumed for design and G the acceleration of gravity.
1.2 The 1923 Kanto Earthquake
Damage to engineered buildings by the 1923 Kanto earthquake left
both successes and failures. Although reinforced concrete buildings wereconsidered to be the most earthquake resistant in those days, the earthquake
revealed that some of them were very dangerous. The guiding principle wasto keep the building deformation small. Stiff buildings generally fared well.
It was reported that buildings designed along the principles of strong boxes237

October 2009, Incheon, Korea

Figure 1: European-Style Structures Heavily Damaged(1891 M8.0 Nobi Earthquake)were safe whereas those of skeleton framing with weak curtain walls
invariably suffered great damage.
Shocked by the devastation by the earthquake, building engineers
realized the need for an earthquake resistant building code. And k = 0.1 and0.15 were specified for general structures and chimney-like structures,
respectively. These numbers were based on the estimated acceleration of
0.1G in the up-town area of Tokyo.
1.3 From Conservative to Obsolete
These values of k’s were incorporated into the revised 1924 Building
Code together with the height limit of 31m. The experience of stiff building
suffering less damage left a continued effect on the Japan’s earthquake
resistant design. The 1924 Building Code remained practically unchanged
until the 1948 Fukui earthquake that claimed about 4,000 lives. A new
Building Standard Law introduced in 1950 increased the design seismic
coefficient from 0.1 to 0.2. The allowable stresses of building materials for
short time seismic loading conditions were set at about twice the value
allowed in the 1924 code.
Although nearly 10 earthquakes with almost or over 1,000 death tolls
took place after the 1923 Kanto earthquake, urban areas were not seriously
affected until the 1948 Fukui earthquakes. And hence, a rather conservative
earthquake resistant design continued to be made together with the 31m
height limit. In the 1950 Law, the effect of flexibility was taken into
account by gradually increasing k value for the portions above a certain
height of a building. Practicing engineers were disappointed, because
design of tall buildings became even more difficult.
In the early ‘50’s, studies were vigorously carried out on the effective
dynamic k value, the probabilities of destructive earthquakes and the effectsof sub-soil conditions. In 1955, the Building Standard Law Enforcement

238

New Technologies for Urban Safety of Mega Cities in Asia

Order was modified to reduce k by taking into account the seismicity of the
district and subsoil conditions.
1.4 Height Limit Lifted
By reading papers published in the 50’s and 60’s, we could see howmuch study Japan’s researchers and engineers performed in that period,
especially on the dynamic effects of earthquakes.
In 1959, the first systematic research started to investigate thepossibility of construction of a tall building in Japan. The 24-storiedbuilding was modeled by a shear building with 5 concentrated masses andthe dynamic analysis was carried out by using an analog computer. This
research was followed by several similar studies. General conclusions fromthese studies were that the 31m height limit could at least be partially lifted.
The height limit of 31m was finally lifted in 1963, and the Japan’s first
157m tall building was completed in 1968.
The 1963 revision of the Building Standard Law was such that, for thetime being, the current Law at that time was to be used for a building withless than 45m in height.
When the construction of a taller-than-45m
building was proposed, a special examination board individually reviewed
the soundness of the design. This approach was effective to encourage
engineers with different ideas for the earthquake-resistant design of tallbuildings.
1.5 Pitfalls under Our Eyes
Japan’s earthquake engineering seemed to be making considerable
advances. We had come to be able to build tall buildings in one of the mostearthquake prone regions in the world.
During the 1968 Tokachi-Oki earthquake, however, a number ofreinforced concrete buildings were badly damaged. They were mostly lowrise and earthquake-resistant designed. The most notable mode of damage
was the explosive shear failure of short columns due to the lack of ductility.
Lessons from this earthquake led to the 1971 revision of the BuildingStandard Law.
Many researchers and engineers, however, thought that the Japan’searthquake design code was obsolete because of the conservatism assumed
in the past. A 5-year research and development project started in 1972 to
update the then existing code by taking account of most advanced
knowledge in the field. The outcome of the study resulted into the 1981
revision of the Building Standard Law and also incorporated in earthquakeresistant design regulations of several other structures. A number of newconcepts were introduced. (1) Higher lateral seismic shear force in the upper
part of a structure than that used in the previous codes, (2) Consideration of
the effect of story deflection in the building, and (3) Two levels of design
earthquake motion with the concept of ductility and ultimate strength.
While vigorous studies were being made to improve an obsolete code
into a modern one, those buildings we thought had been conservatively
designed were damaged again by the 1978 Miyagi-Ken-Oki earthquake.

Failures and Successes of Japan’s Earthquake Engineering239

October 2009, Incheon, Korea

2. THEN, THE KOBE EARTHQUAKE
2.1 Our Worst Failure in Recent Years
At 5:46 in the early morning of January 17, 1995, a magnitude 7.2
earthquake rocked the city of Kobe and its vicinity with a total population ofalmost 2 million. Since earthquake disaster mitigation programs had
previously been directed toward the Tokyo area, both officials and citizens
in the hardest hit region were largely unprepared. The nation was also
appalled by the lack of leadership and absence of crisis management at thenational level.
The 1995 Kobe earthquake revealed that we had made another andone of the biggest failures in recent years. Until then, we had been luckythat strong earthquakes did not take place near our urban areas for almost
half a century. During the same period of time, Japan’s earthquake
engineering technology made significant advancement.
By simply
combining these two apparently independent facts, we were beginning towrongly believe that Japanese structures and cities had become strong
enough to survive even severe earthquakes.
2.2 Self-Confidence Totally Shattered
The death toll reached about 5,500 in a fortnight, making it the worst
earthquake since the 1923 Kanto earthquake. Within the five years
following the earthquake, the death toll increased by another 900 due to theindirect causes. About 100,000 houses and buildings were totally destroyed,
and more than 100 reported fires burned down about 7,000 houses killingsome 560 people. The region's infrastructures were crippled, paralyzing
business and financial operations. The direct and indirect damages were
estimated at 37% of the total property in the stricken region, or 1.6% ofGDP.
We realized how self-conceited we had been about the earthquake

Figure 2: Modern Bridges Collapsed in Kobe
240

New Technologies for Urban Safety of Mega Cities in Asia

safety of our structures and communities. Before the Kobe earthquake, wewere beginning to place more emphasis on economic and social issues ofearthquake disasters than on their technical and engineering aspects. But,
hundreds of thousands of the traditional Japanese wooden houses weretotally destroyed, and a number of non-ductile reinforced concrete bridges
and buildings built according to the old codes were badly damaged. We
were forced to accept the fact that strength of structures is still a crucial
issue in Japan’s earthquake risk mitigation.

3. AFTER THE KOBE EARTHQUAKE
3.1 Headquarters for Earthquake Research Promotion Established
The Kobe earthquake has greatly changed Japan’s earthquake disastermitigation policies. In July, 1995, half a year after the earthquake, theSpecial Measures Law on Earthquake Disaster Prevention was proposed by
Parliament Members, and was immediately enacted. Based on this Law, theHeadquarters for Earthquake Research Promotion was established in thePrime Minister’s Office to conduct the basic and comprehensive research ofseismology on a nationally integrated way. The Basic Disaster Prevention
Plan, often referred to as the constitution for disaster mitigation issues, wasrevised in June 1997, expanding contents related to earthquake and tsunami
disasters.
The Headquarters evaluates and disseminates information on thecurrent seismic activities of Japan based on the in-depth analyses by experts.
When a significant earthquake occurs, by collecting all available records,
the Headquarters disseminates a unified opinion about the earthquake to the
public through the media. Establishment of the Headquarters is one of thebest legacies that the Kobe earthquake has left.
3.2 Construction of “E-Defense”
Before the Kobe earthquake, it was hard to imagine Japanese
structures would fail in a similar way that some structures did in the otherparts of the world. We had, however, to accept that structures still collapse
and kill people, and that there are millions of old and/or weak houses, andalso thousands of modern-looking but low-quality structures in large
urbanized areas in Japan. Assessment of the earthquake strength of existing
structures and of the effects of their strengthening was mandatory. Unlessthese weaker structures are properly strengthened, the tragedy of Kobe will
happen again.
Limited damage has to be tolerated when structures are subjected toan extremely strong earthquake, otherwise the construction cost will become
unacceptably high. New design and effective strengthening methods must
be based on the understanding of the reliable characteristics of structural
failures. Full-scale collapse tests were thought necessary to eliminate
scaling effects inherently involved in scale-model tests. A large-sized 3dimensional shaking table “E-Defense” was constructed for this purpose.
The table size is 20m×15m, and the maximum testing weight is 1,200 ton-f

Failures and Successes of Japan’s Earthquake Engineering241

October 2009, Incheon, Korea

roughly corresponding to the weight of a real-sized 6-storied reinforced
concrete building with a floor area of 20m x 15m.
In the collapse tests of traditional Japanese wooden houses, two
identical wooden houses were placed on the shaking table side by side.
Then one of them was strengthened, and both were subjected to one of thestrongest 3-D shaking recorded during the Kobe earthquake. The nonstrengthened house collapsed within some 10 seconds, while strengthened
one survived the strong 3-D shaking in spite of substantial damage. The
tests were televised and made much stronger impact to the people about thesignificance of structural strengthening than any of the previous efforts
made by municipal governments. Since then, “E-Defense” has been used
for collapse or failure tests of, among others, reinforced concrete buildings,
steel frames, reinforced concrete bridge piers, multi-storied woodenbuildings, components of nuclear power reactors.
3.3 K-NET, Hi-net, and F-net
The national program of monitoring earthquakes started in August
1997. This program consists of establishment of seismometer and GPS
station networks, and active fault surveys. Today, there are about 3,500
seismometers at around 1,800 locations covering Japan, about 2/3 of which
are maintained by the National Research Institute for Earth Science andDisaster Prevention (NIED).
K-NET is a network of about 1,000 digital strong-motion
seismometers installed on the free field at an average station-to-station
distance of about 25km. The seismometer has a maximum measurable
acceleration of 2,000 cm/s2. Hi-net system utilizes about 800 velocity-type
seismometers to obtain precise ground motions. Seismometers are encasedin anti-pressure vessel and placed with an average spacing of 15 to 20km.
They are located at the bottom of a bore hole of 100m or deeper to eliminate
noises caused by human activities. Two strong-motion acceleration-type
seismometers are installed at each of the Hi-net stations, one at the bottomof the bore hole and the other on the free field. F-net is a network of about
70 broadband seismometers with a natural period of 300s. The records from
F-net are used for researches of earthquake source mechanisms and thestructure of the earth’s interiors.
Records from the networks are freely obtained through the Internet
within the shortest possible time. In the case of the Niigataken Chu-etsu
Oki earthquake of July 16, 2007, which may be known for its damage to anuclear power station, 390 records were obtained by K-NET alone.
3.4 Earthquake Early Warning (EEW)
In an attempt to best utilize the records from the dense seismometer
array, a 5-year research program started in 2003 on the real-time estimation
and warning of earthquake motions. Two major organizations in thisprogram were JMA (the Japan Meteorological Agency) and NIED. The
purpose of the researches was to develop a system of real-time
determination of seismic parameters, and transmission of the seismic
intensity and the expected arrival time at a site of interest, within several

242

New Technologies for Urban Safety of Mega Cities in Asia

seconds after the earthquake occurrence but before the arrival of groundshaking.
The NIED’s system is able to determine the epicenter within a few
seconds when P-waves are detected at 2 stations, by also utilizing theinformation that records have not reached the other near-by stations.
Presently data are collected from the JMA’s tsunami and earthquake
detection network consisting of 200 strong motion seismometers and the
NIED’s Hi-net consisting of about 800 velocity-type seismometers. All thedata are sent to and analyzed by JMA in real-time, and the results
disseminated from JMA. The system went into full operation on October 1,
2007.
JMA issues two kinds of EEW: One for the general public, and theother for the special users. The EEW for the general public is transmitted
through TV, radio, and mobile phones. The special advanced users will
directly receive the successively renewed information from JMA and use it
in their most effective way. Schools, hospitals, or plants may be able to findtheir best applications:
I do believe in the great potentiality of EEW, but at the same time, I
understand the general dissatisfaction about EEW regarding the very shortlead time and accuracies. In spite of the present shortcomings, there still are
a number of fields where the EEW can be practically and effectively used
for earthquake disaster mitigation.

4. NATURE DISLIKES US?
I still vividly remember the scenes in the hard-hit area in Kobe after almost
15 years. I was at a loss, because, very foolishly, I was beginning to think
our structures had become strong enough to resist a most powerfulearthquake like the one that devastated Tokyo and Yokohama in 1923. I
could not imagine our bridges collapsing so badly. Even at that time, ourbuilding codes were reasonably well composed, we built structures withgood materials and workmanship, and we thought we knew the significanceof preparedness. Then, why did such a disaster take place?
The ground motion was much stronger than those previously recordedin Japan. But, it should have been expected. Because seismometers had
been only sparsely located before the Kobe earthquake, we could only rarely
record very strong ground motions. Structures designed according to thecontemporary standards were found earthquake resistant. But, we had not
paid enough attention to a large number of low-quality structures. Wooden
houses had been built according to old building codes, many reinforced
concrete structures had been designed taking insufficient notice of ductility,and hundreds of bridges had been constructed before we learned the lessonsof the 1971 San Fernando earthquake or even those of the 1964 Niigata
earthquake.
But, I do not think the root of our failures was simply scientific ortechnical. To get to the heart of the issue, we have to consider thecircumstances surrounding the society, and the subsequent attitudes ofearthquake experts. During the 70’s and 80’s, Japan’s economy was“bubbling.” "Make it faster" was a slogan of the time. After having

Failures and Successes of Japan’s Earthquake Engineering243

October 2009, Incheon, Korea

successfully constructed the Shin-Kansen bullet train, expressways, andnumerous tall buildings, we had become too much confident of what we had
been doing.
Excellence accompanies arrogance. We had become arrogant andself-conceited in spite of our ignorance, and we did not try to clearly tellpeople what we knew as well as what we did not know. When people began
to think earthquake prediction would soon become practical, scientists failed
to tell people what they do under the name of earthquake prediction were
simply basic studies of earthquakes. In fact, practical prediction was still
very far. Engineers also mislead people. It was true we could build
earthquake resistant wooden houses. But when it was wrongly interpreted
wooden houses were generally strong against earthquakes, we did not
rectify the difference.
The problem of earthquake disaster mitigation in Japan, especially inlarge cities, is huge and heavy. Urban areas are full of potentially hazardous
structures. Practical earthquake prediction is difficult to make, we havemillions of low-quality houses in densely built-up areas, many of them are
inflammable, and the number of houses retrofitted after the Kobe earthquake
is appallingly small.
Always only after a big disaster, we realize that the nature is notalways kind to us, that we are so small and powerless in front of it, and that
we know so little about it. I would like to emphasize that experts should try
to more seriously learn the laws of nature. We should not forget that ourignorance and arrogance often magnified disasters in the past.

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TRAP DOOR TESTS FOREVALUATION OF STRESS DISTRIBUTIONAROUND A BURIED STRUCTUREHIROAKI EBIZUKA
Graduate Student
Department of Civil Engineering, The University of Tokyo, Japanebizuka@iis.u-tokyo.ac.jp
REIKO KUWANO
International Centre for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japankuwano@iis.u-tokyo.ac.jp

ABSTRACTA trap door test apparatus is developed to evaluate the change in earthpressures acting on a buried structure in an embankment due to differential
settlements. Base of a soil chamber consists of five separated blocks, any
combination of those can move downward, in order to simulate the unevensettlement. Small load cells were placed on the base blocks to measure theload distribution. Change in stress and deformation within the model
ground are tried to be captured also by the technique of shear wave velocity
tomography using a series of bimorph piezo-ceramic elements.
1. INTRODUCTION
Earth pressures acting on underground structures are highly dependent
on the interaction between ground and structure. Increase in the verticalearth pressures acting on a buried structure in high embankment should be,therefore, considered, depending on the size and depth of structure and typeof foundation, since differential settlements are often expected in suchconditions, as schematically shown in Figure 1. However, in practice, theincrement of vertical earth pressures on underground structures is estimatedin the empirical manner, mainly based on the information of past earthpressure measurements in the limited number of sites (see for example
General guidelines for road earthworks, 1999). In such estimation, thedegree of settlement and/or mechanical properties of backfill materials are
not always taken into account.
Kuwano et al. (2007) investigated the effects of differential
settlements on earth pressures acting on a buried structure in sandy soil by aseries of trap door tests (see Figure 2). It was found that the size, shape andburial depth of a buried structure and mechanical properties of backfill soil
are governing factors for the increment of vertical earth pressure at the topof the structure, while the construction/settlement history showed only
minor effects. It was also reported that even a simple calculation, where the245October 2009, Inchon, Korea

friction forces generated between the soil mass above the structure andsurrounding soil are taken into account, can offer reasonable estimation for
the increment of earth pressure. However, due to the limited performance ofearth pressure transducers used in the experiment, details of the earthpressure distribution were not clearly understood.
A sophisticated trap door apparatus is newly developed in thisresearch, in order to improve the previous study. Shear wave velocity
tomography technique is also attempted in the soil chamber for theevaluation of stress and strain condition within the model ground.

Figure 1: Increment of the earth pressure due to the uneven settlement.

Outline of trap door test

１B～４B

box／pipeB

down
Location of earth pressure
cell

down
top
side

600

1

5

base
2

4

6

150

7
150

3
250

445

250

110

445

(mm)

Figure 2: A soil chamber having separated moving base platens andlocation of earth pressure transducers (Kuwano et al.2007).

246

New Technologies for Urban Safety of Mega Cities in Asia

2. A TRAP DOOR APPARATUS
2.1 Soil chamber
A soil chamber for trap door testing is constructed, the inside of whichis shown in Figure 3. It can accommodate model ground of 700mm wide,
294mm long and 555mm high. The base of the chamber consists of five
separated movable blocks whose size is 99.8mm wide, 293.6mm long and
105mm high, and fixed parts in both sides, in order to create unevensettlement in the model ground, as schematically shown in Figure 4.

5 movable parts
Figure 3: Inside of the soil chamber

Figure 4: Reproducing an uneven settlement in model ground

Each base block is equipped with five two-way load cells to measure
the load distribution on the base, as shown in Figure 5. A load cell is

Trap Door Tests for Evaluation of Stress Distribution around a Buried Structure247

October 2009, Inchon, Korea

attached with a plate of 19.8×199.6mm. Its loading capacity is 0.3kN for
both normal and shear forces.

a) Base blockb) Load cell
Figure 5: Movable base block with small load cells

2.2 Movable base
Figures 6 and 7 present the device for the control of base blocks.
Descent or ascent of the lower shaft controlled by a motor is transmitted tothe upper shaft only when the upper clamp is tightened, so that any
combination of blocks can be chosen to move or stay. Overall shape of theapparatus is shown in Figure 8.
850

460

260

Bearing
guide

900
405

Upper
clamp

235

Lower
clamp
Motor

Figure6: Device for controlling movement of base block248

New Technologies for Urban Safety of Mega Cities in Asia

Figure7: Upper shafts and clamps

Figure8: Overall shape of the trap door apparatus

2.3 Tomography of shear wave velocity in the model ground
Tomography of shear wave velocity measurement is attempted in the model
ground. Bimorph piezo-electric ceramic elements, so called bender elements,
are used for transmitter and receiver of shear wave. Forty-six elements areused in total. Twenty-eight elements are placed in both sides of the model

Trap Door Tests for Evaluation of Stress Distribution around a Buried Structure249

October 2009, Inchon, Korea

ground. Nine elements are located at the bottom and surface, as shown in
Figures 9.

Figure 9: Bender element and its arrangement
Magnitude of shear wave velocity in soil generally reflects its small strain
stiffness, which is mainly dependent on current state of density and stress.
Technically speaking, then, the distribution of shear wave velocity may givesome important information on the stress condition in the ground. Further
study is now underway.

3. SUMMARY
A sophisticated trap door apparatus is newly developed in this study, inorder to investigate effects of differential settlements on earth pressures
acting on a buried structure. Shear wave velocity tomography technique is
attempted for the evaluation of stress states within the model ground.

REFERENCES
General guidelines for road earthworks - culvert work -, 1999. Japan roadassociation, ISBN 978-4889504101, Maruzen Print Co. Ltd. (in Japanese).
Kuwano, R., Horii, T. and Kohashi, H., 2007, Increment of Earth Pressure
Acting on a Buried Box Structure due to Differential Settlements, New
Frontiers in Chinese and Japanese Geotechniques, Proceedings of the Third
Sino-Japan Geotechnical Symposium, 2007, 309-314.

250

New Technologies for Urban Safety of Mega Cities in Asia

FAILURE MECHANISM AND
SEISMIC CAPACITY OF RC FRAMESWITH URM WALL CONSIDERINGBEAM DEFORMATIONKIWOONG JIN
kwjin@iis.u-tokyo.ac.jp
Graduate Student, Graduate School of Eng., The University of Tokyo, JapanHO CHOI
Institute of Industrial Science, The University of Tokyo, Japan
choiho@iis.u-tokyo.ac.jp
NORIYUKI TAKAHASHI
Institute of Industrial Science, The University of Tokyo, Japanntaka@iis.u-tokyo.ac.jp
YOSHIAKI NAKANOInstitute of Industrial Science, The University of Tokyo, Japaniisnak@iis.u-tokyo.ac.jp

ABSTRACTThe objective of this study is to evaluate in- and out-of-plane seismic
capacity of unreinforced masonry (URM) walls built in reinforced concrete(RC) frames. For this purpose, RC frames with unreinforced concrete block(CB) wall for typical school buildings in Korea are experimentallyinvestigated to evaluate their failure mechanisms and seismic capacity.
One-fourth scale, one-bay specimens having different boundary condition of
CB walls due to beam deformation, which is considered one of importantfactors affecting their out-of-plane failure, are designed, and in-plane tests
under cyclic loadings are carried out as a first step herein. In this paper, thefailure mechanism and the load bearing capacity of overall frames due tobeam deformation are discussed.

1. INTRODUCTION
In some earthquake-prone regions of Asia, Europe, and Latin America,
serious earthquake damage is commonly found resulting from catastrophic
building collapse. Such damaged buildings often have unreinforced masonry(URM) walls, which are considered non-structural elements in structural
performance even though URM walls may interact with boundary frames as
has been often found in the past damaging earthquakes.
In the past few years, the authors have conducted cyclic loading tests of fullscale reinforced concrete (RC) frames with unreinforced concrete block(CB) walls to investigate their structural characteristics including residual251

October 2009, Incheon, Korea

seismic capacity (Nakano et al., 2005). The specimens had rigid beams
above and below the CB wall, as was generally employed in otherexperimental researches. However, experimental studies related to theeffects of boundary condition of CB walls on their out-of-plane failure due
to beam deformation, as well as the following strength degradation of theframe, are necessary to fully understand their seismic capacity. For thispurpose, 1/4-scale, one-bay specimens having different boundary conditionof CB walls due to beam deformation, which is considered one of importantfactors affecting their out-of-plane failure, are designed, and in-plane tests
under cyclic loadings are carried out as a first step herein.

2. OUTLINE OF EXPERIMENT
2.1 Prototype building and experimental parameters
The test specimens are designed according to the standard design of
Korean school buildings (referred to as “prototype building” shown in Figure1) in the 1980’s (The Ministry of Construction and Transportation, 2002),
which is the same as the full-scale test previously investigated (Nakano et al.,2005). In this study, 4 specimens having different levels of axial load (firstand fourth story) and different boundary conditions of beam (rigid andflexural beam) are tested under cyclic loading. Among these specimens, test
results of the 2 specimens with different boundary conditions of beam under
the axial load assuming a first story are discussed in this paper.
4,500

4,500

4,500

[unit : mm]

7,500

10,000

2,500

4,500

Figure 1: Standard design of Korean school buildings in the 1980’s
2.2 Design of small-scale specimen
Figure 2 shows the two types of specimens. They are an infilled wall typewith rigid beam (IFRB) and with flexural beam (IFFB), respectively. The
design details and methods for each member are briefly described as follows.
2.2.1 Columns and beams
The size of column section is 1/4 of that of prototype building. The
axial stress in columns, the ratio of longitudinal reinforcement, and that ofshear reinforcement are almost same as the prototype building. As shown in
Figure 2, the upper beam of specimen IFRB is designed to remain elastic
even after the columns and CB wall fail. On the other hand, specimen IFFB

252

New Technologies for Urban Safety of Mega Cities in Asia

Pin
300

140 270

D6@30
Steel Column

2-D10

1320
610

8-D6
D3@70
96×48×48
8-D19
D8@70

300

300

1210
610

8-D6
D3@70
96×48×48
8-D19
D8@70

160

2-D10

150110890

110 150

150110170 110 170

1410

890

1101501410

450

170 110 170
450

5

9

48

30
48

9

(a) Specimen IFRB(b) Specimen IFFB
Figure 2: Details of specimens (unit:mm)

6 9 16 9 16 9 16 9 696

48

Unit : mm

Figure 3: Details of small scale CB unit

Photo 1: Small scale CB unit

is designed to have steel columns above the upper beam to simulate themoment distribution of the prototype building (typical 4-story building)shown in Figure 1. The upper beam with a rectangular section is designed to
fail in flexure, where the shear-to-flexural strength ratio (QSU / QMU) and the
maximum deflection level within elastic range are both similar to those of
the prototype building.
2.2.2 Concrete Block units
The concrete block unit is 1/4 of that of the full-scale unit. Threelayered CB prism specimens are tested, where the cement-to-sand ratio isadjusted so that the strength and stiffness should be close to those of the
full-scale. It has three hollows inside and a half-sized hollow on both ends
as shown in Figure 3 and Photo 1.
2.3 Material test
Tables 1 through 3 show the material test results, where the values
represent the average of 3 samples in each test. Although the design strengthof concrete specified in the standard design of Korean school buildings in
the 1980’s is 21 MPa, the compressive strength of test pieces exceeds thedesign value as shown in Table 1. The yield strength of reinforcementshows higher values by 5 to 20% than the nominal strength. The
compressive strength and Young’s modulus from the 3 layered CB prism
tests are around 90% and 50% of the full-scale CB prism, respectively.
Although the Young’s modulus of CB prism is not reproduced, it is foundthrough previous investigations according to the Equations (1) and (2)(FEMA 306, 1998) that the reduction of Young’s modulus does not havemuch effect on the shear strength Vc of CB wall, and those 1/4-scale CB
units are therefore applied to the test specimens.

Failure Mechanism and Seismic Capacity of RC Frames with URM Wall Considering Beam Deformation

253

October 2009, Incheon, Korea

Table 1: Mechanical properties of concrete (Average)
Compressive strength
30MPa

Elastic modulus
2.1×104MPa

Split tensile strength
2.8MPaTable 2: Mechanical properties of reinforcement
Bar
D3 (SD390)
D6 (SD345)
D6 (SD785)
D10 (SD785)
D10 (SD295)

Tensile Young’s
Yieldstrength strength modulus
(MPa)
(MPa)
(MPa)
Hoop / Column
420
495 1.90×105
Main bar / Column
365
525 2.09×105
Stirrup / Flexural beam
890
1,150 2.01×105
Top main bar / Flexural beam
960
1,080 1.95×105
Bottom main bar / Flexural beam360
520 2.05×105
Use / Member

Table 3: Mechanical properties of concrete block and joint mortar
Concrete block
Joint mortar
Block prism*
Compressive strength
Young’s modulus
Compressive strength
21.6 (20.8)MPa
6.5 (7.3)MPa
1.0 (2.0)×104MPa* 3 layered specimen, ( )：Material test results of full-scale CB unit

Vc = Weq ⋅ t ⋅ f m ⋅ cos θ

(1)
0.1

⎛ 4 ⋅ Ec ⋅ I c ⋅ hm ⎞⎟ ⋅ ldWeq = 0.175 ⋅ ⎜⎜
4 ⎟
E
⋅
t
⋅
⋅
h
sin
2
θ
⎝ m
⎠

(2)

where Vc is the shear force carried by the equivalent diagonal strut of CB
wall, Weq is the equivalent strut width, t is the thickness of CB wall, fm is the
50% of prism strength, θ is the angle of CB wall height to length, Ec is theYoung’s modulus of concrete, Ic is the moment of inertia of column, hm isthe height of CB wall, Em is the Young’s modulus of CB prism, h is thecolumn height, and ld is the diagonal length of CB wall, respectively. The
joint mortar has the cement-to-sand ratio of 1:3.5, which is generally used in
Korea and the same with the full-scale specimen (Nakano et al., 2005).
2.4 Loading plan

The loading system of specimen IFFB is shown in Figure 4. For theother specimen IFRB, a steel beam is placed between the loading beam andrigid upper beam to have the same loading point with specimen IFFB.
Cyclic lateral loads are applied to each specimen through the loading beamtightly fastened to the specimen.
Figure 5 shows the loading history, where a peak drift angle (R) is
defined as “lateral deformation (δ) / column height (h0=610mm)”. As shownin the figure, peak drift angles of 0.1, 0.2, 0.4, 0.67, 1.0, and 2.0% are plannedand 2.5 cycles for each peak drift are imposed to eliminate one-sided
progressive failure (unsymmetric failure pattern in positive or negative
loadings). It should also be noted that 0.4% loading is imposed after 1.0% to254

New Technologies for Urban Safety of Mega Cities in Asia

425

Actuator for lateral loading

Loading beam
Negative
directionloading

1410

Positive
directionloading

500 390

Actuators forvertical loading

Target displacement (mm)Figure 4: Test setup of specimen IFFB (Unit:mm)
16
12
8
4
0
-4
-8
-12
-16

0.1

0.2

0.4
1.0
0.67
Peak drift angle, R (%)

0.4

2.0

Figure 5: Loading history
investigate the effect of small amplitude loading (i.e., aftershocks) after large
deformation. A constant axial load of 96kN is applied to each specimen.
2.5 Measurement plan

The measurement system of specimen IFFB is shown in Figure 6. The
relative lateral displacement between upper and lower beams, the verticaldisplacement of each column, and the diagonal deformation of frame aremeasured. To measure the curvature distribution in columns, displacementtransducers (LVDTs) are attached on both sides of each column at aninterval of 150mm. Strains of longitudinal and shear reinforcement incolumns of both specimens and in the upper beam of specimen IFFB aremeasured.
Strain gauge
Strain gauge

Displacement
tranducers forcurvature

Lateral displacement
at each column section

Lateral displacement

Beam deflecion
Verticaldisplacement
Diagonal
deformationof frame: LVDT: Strain gauge

Figure 6: Measurement system (Specimen IFFB)

Failure Mechanism and Seismic Capacity of RC Frames with URM Wall Considering Beam Deformation

255

October 2009, Incheon, Korea

3. TEST RESULTS
3.1 Failure patterns

Figure 7 shows the crack patterns of both specimens at their maximum
strength. The failure patterns observed in each specimen are as follows.
3.1.1 Specimen IFRBSpecimen IFRB has flexural cracks in RC columns and vertical andhorizontal cracks in joint mortar between CB units at the first cycle with peak
drift angle of +0.1%. During +0.2% loading, stair-stepped cracks in the CB
wall due to diagonal strut are observed, and some cracks in joint mortar
extend diagonally into CB units. Clear shear cracks at the top of tensile
column and the bottom of compression column are observed at the peak drift
angle of +0.4%. The crack running through the entire bed joint (horizontal
joint) under the middle row of the CB wall induces slippage at the joint
during -0.67% loading. Since the shear cracks at the column base ofcompression side rapidly open with increase in the drift angle up to -1.8%, thetest is terminated during the first cycle of -1.0% loading.
3.1.2 Specimen IFFB
The specimen IFFB shows a failure pattern totally different from thatof specimen IFRB. At the first cycle with peak drift angle of +0.1%, flexural
cracks develop in columns and beam, and diagonal cracks into CB units areobserved in the top row of the CB wall. Since the beam deformation causes
large compressive force into the CB units at the compression corner of thewall underneath the beam, resulting in their diagonal cracks and crushing,
the area of bed joint under the top row of the wall reduces and eventually
the joint becomes relatively weaker than other rows. As a result, cracks
causing slippage at the joint successively occur fully under the top row. It is,therefore, considered that severe damage in CB units and the following
slippage at the joint caused by beam deformation imply the higher
possibility of out-of-plan failure due to orthogonal excitations even in asmall drift ratio. During +0.2% loading, the remaining part of CB wall under
the top row acts as a diagonal strut developing stair-stepped cracks in thewall. Clear shear cracks develop in columns and beam at the peak drift
angle of +0.4%. Between the peak drift angles of 0.67% and 2.0%, thedamage in the beam is concentrated on its critical sections. Since the cracks
at the critical sections are abruptly widened and the strains of longitudinal
reinforcement in the beam significantly increase, the test is terminated at thedrift angle of +3.0%.
3.2 Relation between lateral strength and drift angle
3.2.1 Specimen IFRBAs shown in Figure 8(a), the maximum strength of 48.6kN is recordedat the drift angle of +0.67% after the longitudinal reinforcement in columns
yield at around +0.60%, and no remarkable strength deterioration is found

256

New Technologies for Urban Safety of Mega Cities in Asia

until the drift angle of +1.0%. Shear cracks at the bottom of compression
column rapidly open at the drift angle of -1.0%, resulting in sudden
deterioration of the lateral load carrying capacity as shown in Figure 8(a).
This specimen finally fails in shear after flexural yielding in columns.
3.2.2 Specimen IFFBAs shown in Figure 8(b), the yielding drift angle of the longitudinal
reinforcement in the upper beam is about -0.67%, and the maximum
strength of 39.8kN is recorded at the drift angle of +1.8% after thelongitudinal reinforcement in columns yield at around +1.3%. No
remarkable strength deterioration is observed until the drift angle of +3.0%.

Negative direction
loading

Positive direction
loading

Positive direction
loadingShearcracks

FlexuralcracksStair-stepped cracks
by diagonal strut

Slippage in the entire
bed joint by sliding shear

Slippage in the entire
bed joint by sliding shear

FlexuralcracksStair-stepped cracks
by diagonal strut

Shearcracks

FlexuralcracksShearcracksLoad(kN)(a) Specimen IFRB (+0.67%)(b) Specimen IFFB (+2.0%)
Figure 7: Crack patterns at maximum strength[+0.4%]Column, Beam50[+0.60%][+1.3%]Column:Main bar yielding[+0.67%]:Shear crack[+0.2%]
40 Column:Main bar yielding
Maximun strength(48.6kN)
CB wall:Stair-stepped[+0.4%]
30
diagonal crack[+0.1%]
Column:Shear crack[+3.0%]
Column, Beam:Flexural crack
20[+0.1%][+0.2%]
Abrupt increase
CB wall:Diagonal crack into
10 Column:Flexural crack
CB wall:Stair-stepped diagonal crack,of damage at
CB unit in top row,
critical beam section
diagonal crack into CB unit
CB wall:Crack in joint mortar
slippage at top
0
joint
[
+
1.8%
]
[
0.96%
]
-10
Maximun Strength(39.8kN)
Column：Rapid open of-20
shear crack-30[-0.67%]-40[-0.67%]
CB wall:Slippage at middle joint
Beam：Bottom main bar yielding-50-2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Drift angle（R，%）

Drift angle（R，%）(a) Specimen IFRB(b) Specimen IFFB
Figure 8: Lateral strength and drift angle relation

Failure Mechanism and Seismic Capacity of RC Frames with URM Wall Considering Beam Deformation257

October 2009, Incheon, Korea

4. MAXIMUM STRENGTH OF OVERALL FRAME
4.1 Maximum strength evaluation based on column moment distribution
4.1.1 Specimen IFRB
Figure 9(a) shows the curvature distribution and yield hinge zones inboth columns, where measured strains of main bars exceed the yield strain.
They are formed over a distance of column depth D (110mm) at both ends ineach column, and their bending moment distribution assumed from thehinge formation is also shown in the figure. The flexural strength QMU(23.6kN) of each column is evaluated by 2MU / 3.5D, where the ultimate
bending moment MU of columns is calculated based on the plane-section
assumption setting the ultimate strain εCU at the compression fiber ofconcrete equal to 0.003 with an equivalent rectangular stress block
coefficient 0.85. The overall lateral strength P derived from the assumptions
above agrees well with the recorded capacity as shown in Figure 10 (a).
4.1.2 Specimen IFFB
The curvature distribution and yield hinge zones in both columns areshown in Figure 9(b). They are formed over the height of 4.0D at the bottom of
tensile column and 1.0D at the bottom of compression column, respectively.
The bending moment distribution assumed from the yield hinge formation is
also shown in the figure. The bending moments at the beam-column joints are
determined to meet the moment equilibrium, where the beam end at the top of
P=48.6kN (Maximum Strength)

Left column

Right column

Strain gauge position（mm)

600
1.0D

1.0D

500

1.0D

400
300
200

Yield
hinge
zones

h0
(≒3.5D)

1.0D

1.0D

100

QMU
(＝23.6kN)

QMU(＝23.6kN)

MU

0

MU

h0
(≒3.5D)
1.0D

MU=4.5kN・m-8 -4 0 4 8-5Curvature (×10 /mm)

1.0D

MU

MU

Yield
hinge
zones

1.0D
-8 -4 0 4 8-5Curvature (×10 /mm)(a) Specimen IFRB
PL

PR
P＝PL+PR=39.8kN(Maximum Strength)

Left column
Strain gauge position（mm)

600
500

Yield
hinge
zones

h01,L
(≒1.5D)400

QMU,L(＝30kN)

300
200

4.0D

100
0

-8 -4 0 4 8-5Curvature (×10 /mm)

QMU,R(＝10kN)h02(＝270mm)Right column

h01,R(≒4.5D)

Yield
hinge
zones

4.0D
MU

MU
1.0D
MU=4.5kN・m

1.0D-8 -4 0 4 8-5Curvature (×10 /mm)(b) Specimen IFFB
Figure 9: Curvature of columns and moment distribution at maximum strength258

New Technologies for Urban Safety of Mega Cities in Asia

tensile column is assumed yielded while the moments at the bottom of upper
steel columns and at the column top in compression side are derived fromobserved strains, which remain elastic throughout loadings. The ultimate
bending moment of the beam end is calculated based on the same assumption
with that of the column of specimen IFRB, where the tensile axial load (10.5kN) acting in the beam is considered. The flexural strength QMU in eachcolumn is then calculated considering the rest span length (1.5D in the tensile
column and 4.5D in the compression column) above yield hinge zones asshown in Figure 9(b). The overall lateral strength P considering the column
hinge zones agrees well with the recorded capacity as shown in Figure 10(b).
4.2 Maximum strength estimation by practical method

In the previous section, the overall lateral strengths of RC frames with
CB wall are evaluated according to the observed moment (or curvature)
distribution in columns. In the design stage, however, the moment distribution
discussed earlier based on the curvature profile is not given and the lateralstrength can not be predicted as is done in this study. A simplified strength60
40

VC of CB Wall (Eq.(1))

QMU : Hinge zones in columns
neglected

10

' '

0

'

Load (kN)20

QMU : Hinge zones in columns considered

P
P
2QMU

'

30

''

50

-10

P =2QMU + VC

P =2QMU

P

P

-20

'

MU

-40

QMU

-50

MU

MU

-30

-60
-2.5 -2.0 -1.5 -1.0 -0.5

0.0

0.5

'

MU

MU

MU

QMU

QMU

QMU

MU

MU

1.0

1.5

2.0

2.5

3.0

3.5

(a) Specimen IFRB60

PP
Qm+QMU

10

'

'
'

0

P =Qm+QMU+VC
PR

PL

'

Qm

-50
0.0

0.5

PR
QMU, L
QMU, R

QMU

MU

-60
-2.5 -2.0 -1.5 -1.0 -0.5

PL

MU

'

-30
-40

P=QMU,L +QMU,R

'

-10
-20

(Eq.(1))

Qm,QMU: Hinge zones
in columns
neglected'

Load (kN)20

VC of CB Wall

'
'

30

QMU,L, QMU,R : Hinge zones in columns
considered

'

'

40

'

50

MU

MU

1.0

1.5

2.0

2.5

MU

3.0

3.5

(b) Specimen IFFB
Figure 10: Maximum strength of overall frame

Failure Mechanism and Seismic Capacity of RC Frames with URM Wall Considering Beam Deformation259

October 2009, Incheon, Korea

evaluation of the specimens is, therefore, made based on the FEMA 306(1998), where the strength is calculated from column moments neglecting
hinge zones resulting from the presence of CB wall.
In the simplified evaluation, the ultimate strength of the bare frame is first
calculated, and the shear force VC contributed by CB wall is then added to thestrength above to obtain the overall strength. For specimen IFRB, as shown in
Figure 10(a), yield hinges are assumed at both column ends, and the column
strength Q’MU is computed by 2MU / 610mm (column height), where MU isdefined in subsection 4.1.1. For specimen IFFB, as shown in Figure 10(b), thecolumn strength Q’MU in compression side is obtained by the same assumption
with that of specimen IFRB, while the yield hinge is assumed both at the beam
end and at the column bottom to obtain the strength Q’m in tensile side. The
ultimate bending moment at beam end, where the tensile axial load (-2.3kN)
acting in the beam is not taken into account for the practical estimation becauseof its negligible effect on the beam strength and accordingly column strength, isdistributed to the top of tensile column in accordance with the elastic moment
distribution ratio at its top and the bottom of steel column. The shear force VC(15kN for both specimens) of CB wall carried by the equivalent diagonal strut
is computed by Equation (1) (FEMA 306, 1998). The sum of shear forces ofthe bare frames and CB walls, plotted in Figure 10, shows good agreement withthe recorded maximum strength of overall frames in both specimens.
5. CONCLUSIONS

Seismic performance of RC frames with unreinforced CB wall for standard
Korean school buildings were experimentally investigated under cyclicloadings. The major findings can be summarized as follows.
(1) Because of beam deformation above CB wall and resulting different yieldhinge zones, the moment distribution in columns and load bearing capacityof specimen IFFB are totally different from those of specimen IFRB. It
should also be noted that severe damage in CB units and slippage at thejoint is developed in the early stage of loading due to beam deformation in
specimen IFFB, and it implies the higher possibility of out-of-plan failure
even in a small drift ratio when the beam is not fully rigid.
(2) The maximum strength evaluated by the moment distribution alongcolumns considering hinge zones agrees well with the load bearing
capacity recorded in both specimens.
(3) A simplified method consisting of the bare frame strength neglecting hingezones and the contribution of CB wall computed based on FEMA 306(1998) can successfully predict the load bearing capacity of overall frame.
REFERENCES
The Ministry of Construction and Transportation, 2002. A Study on the Seismic Evaluation
and Retrofit of Low-Rise RC Buildings in Korea (in Korean).
Nakano, Y. and Choi, H., 2005. Experimental Study on Seismic Behavior and Crack
Pattern of Concrete Block Infilled RC Frames. New Technologies for Urban Safety ofMega Cities in Asia (USMCA), ICUS/INCEDE Report 2, Singapore.
FEMA 306, 1998. Evaluation of Earthquake Damaged Concrete and Masonry Wall
Buildings. Applied Technology Council (ATC-43 Project).

260

New Technologies for Urban Safety of Mega Cities in Asia

A CASE STUDY OF GROUND CAVE-IN
CAUSED BY SUBSURFACE EROSIONIN LARGE SCALE FILL GROUNDREIKO KUWANO
International Centre for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japankuwano@iis.u-tokyo.ac.jp
YUKIHIRO KOHATA
Department of Civil Engineering and Architecture
Muroran Institute of Technology, Japan
kohata@news3.ce.muroran-it.ac.jp

ABSTRACT
Ground cave-in is usually initiated by the formation of cavity within the
ground due to soil loss. When the location of the cavity is deep in the
ground, the detection of the cavity is not easy. Then it is possible that thehidden cavity expands for a long time to eventually cause sudden largescale collapse.
A case of large scale ground collapse in the old fill ground wasstudied and described in this paper. The underground cavity appeared to becaused by subsurface erosion deep in the ground and to expand/extend
upward till it was ended by the catastrophic ground failure. It highlighted
the importance of proper drainage work in a large scale land fill.

1. INTRODUCTION
A sudden collapse of the ground occurred in the 8th fairway at the Le Petaw
golf course in Hokkaido on April 2, 2009, when a woman golfer
unfortunately stepped on it. She fell into a hidden hole formed underneaththe ground and by the time a rescue team arrived she had passed away.
The hole was 5m deep and 7m wide at the bottom. Although the golfcourse was daily checked by maintenance staff, they could not get any signof the hidden hole even in the morning of the accident. The ground collapse
seemed to have happened all of sudden, as the victim’s son who walked justa couple of meters behind her saw her suddenly disappearing into theground.
A detailed investigation took place by Hokkaido prefectural police,assisted by the authors. This paper reports findings in the investigation,
based on which the mechanism of the hidden cavity formation is discussed.

261

October 2009, Inchon, Korea

2. OUTLINE OF THE COLLAPSE
2.1

Topography and ground condition

The golf course was originally built more than 15 years ago in hilly land, by
filling a valley with local soil. The ground consists of mud rock covered
with silty volcanic ash. The thickness of the land fill seems to be 10 to 15
meters. The surface layer of about 0.5m was added fertile soil for the growthof lawn. It is a gentle slope in the 8th fairway and there used to be a stream
along the east-west direction at the location of the collapse. Although theexact locations are not identified, drain pipes should be installed
underground to carry away the subterranean water while preventing soil
from seeping out. There are several artificial ponds around the fairway forwater hazards in the course, as shown in Figure 1. When the accident
occurred, the ground water level was considered to be higher than usual, as
it was the thawing season.

Ncollapse

The 8th fairway

Figure.1 Photo at the location of collapse (after Asahi Newspaper 090417)
2.2 Underground cavity
The hidden hole had a flask shape with a 1 m wide opening at the groundsurface (see Figure 2), and was 5m deep and 7m wide at the bottom. There
was an about 0.6m deep shallow water pool in the east side of the hole, andthe water flew to the west direction. Noticeable erosion was found in bothwest and east sides at the bottom as schematically shown in Figure 3.
The volume of the soil for the cavity is about 75m3. One of thequestions is that where such amount of soil went. There is a water reservoir
in the down stream of the 8th fairway as shown in Figure 4, where large

262

New Technologies for Urban Safety of Mega Cities in Asia

amount of soil sediment was found. It may be the possible destination of thesoil flown from the cavity.

Figure.2 Opening at the ground surface (from Hokkaido Newspaper)

1～1.5m

5m

West

East
erosion

water
pool

water flow

erosion7m
Figure.3 Schematic of the underground cavity

NLand fill of about 10-15m thick
The 8th fairway
Water hazard
Collapse???

Reservoir
Large amountof soil sedimentRoad

Figure.4 Possible destination of the lost soil

A Case Study of Ground Cave-in Caused by Subsurface Erosion in Large Scale Fill Ground263

October 2009, Inchon, Korea

3. INVESTIGATION BY EXCAVATION
A large scale excavation was carried out around the hole to understand how
and why such a huge underground cavity was created. Soil sample wastaken from three locations to characterize their physical properties.
3.1 Soil pipe discovered beside the hole
Figure 5 is a photo of excavation. Excavated soil was mixture of
volcanic clay, silt, sand, and relatively small gravel, as shown in Figure 6.
Roots of plants were also included, which indicates the excavated strata wasfilled soil.

５ｍ
East

West

Location of
opening at
ground surface

Figure.5 Excavation around the hole

Sand with highwater content

Plant root
Figure.6 Soil in the excavated wall (GL-approx.6m)
At the depth of 8m from the ground surface, there was the boundary
between original stiff ground and filled soil, where a lateral ground cavity of
about 2m wide was discovered in about 20m west from the center of thehole, as shown in Figure 7. The sound of water flow was clearly heard in thecavity. The length of the cavity was at least 6m, but could not be confirmed

264

New Technologies for Urban Safety of Mega Cities in Asia

as the further excavation was not conducted. It seemed to be a path throughwhich soil with water was transported out of the hole.

Figure.7 Natural soil pipe due to the internal erosion

3.2 Search for the destination of the water flow in the soil pipe
Water colored by fluorescent paint was poured into the cavity tosearch for the destination of the water flow in the soil pipe. After 20 minutes,
the colored water started flowing out at the reservoir, 700m down from thecavity. It can be considered that a soil pipe is formed in the ground between
the collapsed location and the reservoir (see Figure 4).
3.3 Location of the water inflow
In the excavation on the east side, the point where the water flew into
the hole was found at about 10m away from the center (Figure 8).

Figure.8 Water inflow at the east side of the hole

A Case Study of Ground Cave-in Caused by Subsurface Erosion in Large Scale Fill Ground265October 2009, Inchon, Korea

4. ESTIMATION OF UNDERGROUND CAVITY FORMATION
Comparison between old and current map of the location revealed that the
ground collapse occurred at the land fill exactly on the old stream, as shownin Figure 9. The locations of the water inflow and outflow were identified ateast and west side of the hole respectively.
Land fill of about 10-15m thickN

The 8th fairway

Old stream
Water hazard
Collapse???

Reservoir
Large amountof soil sedimentRoad

Figure.9 Location of the old stream
Ground appeared to be internally eroded by the natural water pathformed at the old stream. It is like a natural drainage pipe, so that it is calledsoil pipe. As the erosion of the soil at the location of the collapse seemed tobe accelerated for some reason, a distinctive ground cavity was created. The
hidden cavity grew silently, possibly due to the change of ground waterlevel and eventually caused ground collapse. Such a process is
schematically shown in Figure 10. However, the state and the condition of
the installed drainage pipes are not yet examined. Further investigation isrequired in this aspect.

Original stream

Formation of small cavity
due to erosion
at some point

Land fill constructed

Erosion progressed
Cavity and surrounding
loosening expand

Natural water path is formed
along the old stream

Failure of cavity ceiling

By repetition of erosion
and failure of cavity ceiling,a cavity moves upward

Figure.10 Formation of underground cavity

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New Technologies for Urban Safety of Mega Cities in Asia

Kuwano et al. (2006), Sato & Kuwano (2008), Kuwano & Sato (2009)
investigated the mechanism of ground cavity and surrounding loosening due
to the failure of sewer pipes. It was found that the state of water infiltrationand soil properties are the governing factors for the growth of the groundcavity and loosening, while the failure of pipe is a trigger of thephenomenon. Based on the research, the followings are considered to be key
issues for explaining the formation of large underground cavity in this case.
(1) Soil properties
The soil was permeable, subjected to the erosion relatively easily.
Fines can be first flown away with water, which created ground looseningaround the cavity.
(2) Ground water
There was a subsurface water path which can transport soil out of thehole with water. There is also seasonal change in ground water level, which
may accelerate the cavity growth as the saturation of soil at the ceiling helps
failure and expansion of the cavity.
(3) Soil loss
Direct trigger of the formation of natural water path may be a defectof drainage pipe. But the state and the current condition of the pipes have
not yet examined.

5. SUMMARY
A case of large scale ground collapse in the old fill ground was investigatedand described in this paper. The underground cavity appeared to be causedby subsurface erosion deep in the ground and to expand upward till it was
eventually caused the catastrophic failure. It should be noted again theimportance of proper drainage work in land fill construction.

REFERENCES
Kuwano, R., Horii, T., Kohashi, H. and Yamauchi, K., 2006, Defects of
Sewer Pipes Causing Cave-in's in the Road, Proc. 5th International
symposium on new technologies for urban safety of mega cities in Asia,
USMCA, Phuket, November 2006.
Sato, M. and Kuwano, R., 2008, Experimental Study on the Evaluation of
Loose Ground Surrounding a Cavity in Soil, Proc. 7th International
symposium on new technologies for urban safety of mega cities in Asia,
USMCA, Beijing, October 2008, 751-758.
Kuwano,R. and Sato,M., 2009, Basic study for prevention of ground cave-in,
Seisan Kenkyu, Bimonthly Journal of Institute of Industrial Science, The
University of Tokyo, Vol.61, No.4, 57-61 (in Japanese).

A Case Study of Ground Cave-in Caused by Subsurface Erosion in Large Scale Fill Ground

267

SEISMIC FRAGILITY FUNCTION FOR
UNREINFORCED MASONRY BUILDINGSIN KOREA
Jung-Han LEE, Hye-Won KIM, Byung-Cheol PARK and Waon-Ho YI
Structural Safety Research Team,National Institute for Disaster Prevention, Korea
ljhunk@nema.go.kr

ABSTRACTThe objectives of this research are to evaluate the seismic fragility
curve and function for "Slight", "Moderate", "Extensive", "Complete"structural damage states of URM buildings including the major parameterssuch as the interstory drift at threshold of damage state and spectral
displacement in HAZUS and to develop the seismic fragility function of theexisting unreinforced masonry buildings in Korea. To develop the seismic
fragility function of the existing URM buildings in Korea, capacity spectrum
analysis of the URM building using the Midas GEN Ver.741 is surveyed.
From the capacity spectrum analysis results, spectral displacements for 4
kinds of damage state adopting the suitable drift ratio of damage state in
Korea are suggested, and the seismic fragility function for existing URM
building in Korea is developed.

1. INTRODUCTION
In worldwide, huge casualty and economic losses are steadily occurred withcollapsing of the unreinforced masonry buildings due to the earthquakes.
The crustal activity does not affect directly to the Korea different from theJapan, China and there is no experience of destructive earthquakes in thepast. Also, countermeasures against earthquake disasters such as the damage
estimate and disaster reduction measures have not been fully performed.
However, with more than eight hundred earthquakes with medium intensitythat centered on off-coastal and inland areas of Korea during the past 31
years, and due to the great earthquakes which occurred recently inneighboring countries, such as the 1995 Hyogoken-Nambu Earthquake withmore than 6,500 fatalities in Japan, the 1999 Chi-Chi Earthquake with morethan 2,500 fatalities in Taiwan, and the 2008 Sichuan Earthquake with morethan 69,000 fatalities in China, the importance of the future earthquake
preparedness measures is highly recognized in Korea. In many countries,
most of the residential buildings are constructed with unreinforced masonry.
More than 46 percent of buildings in Korea are constructed using
unreinforced masonry. Unreinforced masonry buildings have advantages of
reducing the construction time and are easy to construct. However,unreinforced masonry buildings have limited strength against lateral forces.

269

October 2009, Incheon, Korea

Moreover, most of low rise buildings have not adopted seismic designs, andfor that reason, critical damage can be expected with an earthquake.
Therefore the preparedness of the damage estimate and disaster reduction
measures for the unreinforced masonry buildings which accounted for the
majority of residential buildings is needed for the future earthquakes.

2. PREV I OUS RESEARCH
From the previous research(Yi, W.H., et. al; 2006), a survey on 98 URM
buildings in Seoul is executed by dividing URM buildings into singlefamily housing, multi-family housing, and neighborhood facilities.
Thereby it identifies the distribution of floor number and height; grossfloor area; wall length; wall quantity and ratio; and opening ratio. Based on
the result of the survey, for a modular planning, data about wall and opening
length is extracted from the investigation by types, area-scales, and room
configurations, and proposed are 2 types of a standard drawing for each typeand a design standard for future URM buildings. Because the construction
accuracy of URM buildings is very low and does not meet the current
standard, to improve their seismic performance, a large scale of repairreinforcement would be necessary. Previous research including the shaking
table tests surveyed by Kim, J.K., (1999) and Kwan, K.H., (2001) areinvestigated to evaluate the damage status, drift ratio and the othervibration characteristics for the unreinforced masonry buildings. Fromthe shaking table tests results, damage status and drift ratio at damage arequite different from the HAZUS. And, to evaluate the main variables suchas the response modification factor and the period equation for the seismic
design and seismic capacity evaluation of the unreinforced masonrybuildings, previous research and codes are investigated. From theinvestigated results, 1.5 of response modification factor and 0.049Hn(3/4) ofperiod equation suggested from the KBC-2005 are more appropriate to use.

3. DEVELOPMENT OF SEISMIC FRAGIL I TY FUNCT I ON FOR
URM BUILDINGS
3.1 Fragility Curve by Using HAZUS Classification
In HAZUS, 36 model building types that are used by the methodology
are defined. These model building types are based on the classification
system of FEMA 178, NEHRP Handbook for the Seismic Evaluation of
Existing Buildings [FEMA, 1992]. And 4 kinds of damage state such as“Slight”, “Moderate”, “Extensive” and “Complete” are defined in eachstructural type. From the mean value of spectral displacement at which thebuilding reaches the threshold of damage state and the standard deviation of
the natural logarithm of spectral displacement for the damage state, seismic
fragility curve.

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New Technologies for Urban Safety of Mega Cities in Asia

S d = S d ,ds ⋅ ε ds

(1)

Where, Sd .ds : Median value of spectral displacement of damage state, ds
ε ds : Lognormal random variable with unit median value and logarithmic
standard deviation,
The conditional probability of being in, or exceeding, a particulardamage state, ds, given the spectral displacement, Sd, (or other PESH
parameter) is defined by the function:⎡ 1 ⎛ Sd ⎞ ⎤P[ds Sd ] = Φ ⎢ln⎜⎟⎥⎣ β ds ⎝ Sd ,ds ⎠ ⎦(2)Where, Sd,ds : Median value of spectral displacement at which the building
reaches the threshold of damage state,βds : Standard deviation of the natural logarithm of spectral displacementfor damage state,Φ : Standard normal cumulative distribution function
It is considered that the material nonlinear by a wide use structural
analysis program. It can be evaluated the capacity spectrum curvefor URM buildings by the capacity spectrum analysis in this chapter. It isestimated that the drift ratios of damage states and spectral displacement forbuildings by the capacity spectrum results. It is also estimated that themedium values and seismic fragility curve by using the spectral
displacement. It is developed that the suitable seismic fragility curve for
URM and estimated the adequacy of seismic fragility curve computing
solution in Korea by comparison and analysis of HAZUS and derived one.
Table 1: Parameter of Fragility Curve in Pre-Seismic Code of Analytic Example
Interstory Drift at Threshold ofDamage StateType

Spectral Displacement, inches (cm)SlightModerate

Extensive

Complete

Slight Moderate Extensive Complete
Median Beta Median Beta Median Beta Median Beta
URML

0.0024 0.0048(1/417) (1/208)

0.0120(1/83)

0.0280(1/36)

0.32
0.65
1.62
3.78
1.15
1.19
1.20
1.18
(0.81)(1.65)(4.11)(9.60)

3.2 Seismic Fragility Curve by Using CSM
3.2.1. Verification of Analyzed Program
In this research, the application is verified through comparison andanalysis of practiced experimental results and analytical them of URM by
midas GEN Ver.741. Analytical results are also compared with theexperimental results of 10 unreinforced masonry walls practiced by W. H.
Yi (2003, 2006) to verify the midas program. Representative comparison
specimens are totally 10 unreinforced masonry walls. The list of
specimens and experimental results are shown in Table 2, and 3.
Earthquake Countermeasures for Safer Future in Korea

271

October 2009, Incheon, Korea

Table 2: Specimen List
Label

Size
(h×l)

Aspect Ratio
(h/l)

Wythe
(t)

Axial Stress(MPa)

Opening(h×l)

270W-1F

2.7m×2.7m

1.00

1.0B(190mm)

0.086

-

270W-2F

2.7m×2.7m

1.00

1.0B(190mm)

0.250

-

270W-2F-0.5B

2.7m×2.7m

1.00

0.5B(90mm)

0.250

-

270W-2F-W

2.7m×2.7m

1.00

1.0B(190mm)

0.250

window (1.2×1.5m)

270W-2F-D

2.7m×2.7m

1.00

1.0B(190mm)

0.250

door (2.15×1.0m)

120W-2F

2.7m×1.2m

2.25

1.0B(190mm)

0.250

-

180W-2F

2.7m×1.8m

1.50

1.0B(190mm)

0.250

-

360W-2F

2.7m×3.6m

0.75

1.0B(190mm)

0.250

-

400W-2F

2.7m×4.0m

0.68

1.0B(190mm)

0.250

-

540W-2F

2.7m×5.4m

0.50

1.0B(190mm)

0.250

-

Table 3: Maximum Load of Experimental and Analytical Results of Specimens
Maximum Load (kN)Specimen

Variables
Analytical Results Experimental Results

Ratio of Exp. andAna.

270W-1F

Vertical Load

84.14

81.43

1.03

270W-2F

Prototype136.12134.361.01

270W-2F-0.5B

Wythe

103.75106.440.97

270W-2F-W

Opening(w/wo)

49.72

50.88

0.98

73.65

57.78

1.27

120W-2F

35.89

35.08

1.02

180W-2F

63.43

59.73

1.06

195.84179.16

1.09

400W-2F

192.90199.07

0.97

540W-2F

277.53268.75

1.03

270W-2F-D

360W-2F

Aspect Ratio

It is applied the pushover analysis of URM walls by midas GEN
Ver.741. URM walls are modeling by nonlinear beam elements, and it isapplied that axis stress and material properties of URM walls equal withvalues of specimens. The hinge property of pushover determined ratios ofductility and yield through trial and error method from the experimental
results values. The type of buildings is existing buildings and the prism
press strength applies 6.18 MPa that is result value of material experiment.
In case of the value of shear strength for URM, it is determined 0.14 MPa
from results of existing material experiment and URM walls experimentthrough trial and error method.

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New Technologies for Urban Safety of Mega Cities in Asia

3.2.2 Seismic Fragility Curve
To develop the seismic fragility curve, it is selected an analysis pieceof URM buildings in order to deduce a seismic fragility curve of them indomestic and then achieve the pushover analysis. From the results of
pushover, it calculates the average spectral displacement of each damage
conditions. Each damage conditions is called "Slight", "Moderate","Extensive", and "Complete" which is presented by HAZUS. It calculates
the average spectral displacement through the application of story drift
ratios of HAZUS and Korea Infrastructure Safety and Technology
Corporation (KISTC). From the computed average spectral displacement
and standard deviation, the seismic fragility curve is deduced. It is required
the definition of spectral average displacement and standard deviation
through basic story drift ratios as damage conditions by deducing theseismic fragility curve. In internal URM buildings, it is hardly applied
the HAZUS to internal situation because it is different from structural
systems and construction materials of U. S. URM buildings. So it is proper
an application to employ KISTC guaranteed. It would be comparedwith the results of story drift ratios by two kinds of damage states
were shown in Table 4. Fig. 1~3 show the spectral displacement frompushover analysis.
Table 4: Story Drift Ratios of Each Damage Conditions
SlightModerate
Extensive
Complete
HAZUS

0.0024(1/417) 0.0048(1/208) 0.0120(1/83)) 0.0280(1/36)

Standard ofDomestic

0.0020(1/500) 0.0040(1/250) 0.0067(1/150) 0.0100(1/100)

1000

)
m
m
( 100
t
n
e
m
e
c
la
p
s
i
D 10
l
a
rt
c
e
p
S
1
0.00

SlightModerate
Extensive
Complete
S- HAZUS
M- HAZUS
E- HAZUS
C- HAZUS

0.02

0.04

0.06

0.08

0.10

0.12

Wall Ratio (m2 / m 2 )Figure 1: Entire Spectral Displacements during Damage States

Earthquake Countermeasures for Safer Future in Korea

273

October 2009, Incheon, Korea

1000

)
m
m
( 100
t
n
e
m
e
c
la
p
is
D 10
l
a
rt
c
e
p
S
1
0.00

SlightModerate
Extensive
Complete
S- HAZUS
M- HAZUS
E- HAZUS
C- HAZUS
S_Average

164. 76
71. 7028. 72
14. 2096. 01
41. 15
16. 51
8. 13

0.02

0.04

0.06

0.08

0.10

0.12

Wall Ratio(m 2 / m2 )Figure 2: Spectral Displacements with HAZUS Story Drift Ratios
1000

)
m
(m 100
t
n
e
m
e
c
a
l
p
is
D 10
l
a
rt
c
e
p
S
1
0.00

SlightModerate
Extensive
Complete
S- HAZUS
M- HAZUS
E- HAZUS
C- HAZUS
S_Average

96. 01
60. 11
40. 14 41. 15
24. 0912. 1016. 51
8. 13

0.02

0.04

0.06

0.08

0.10

0.12

Wall Ratio (m2 / m2 )Figure 3: Spectral Displacements with Korea Story Drift Ratios
3.2.3 Proposal of Seismic Fragility Function
It is determined to underestimate the spectral displacement as
application of HAZUS story drift ratios. Therefore it is proper to apply thestandard of Korea Infrastructure Safety and Technology Corporation(KISTC). Spectral displacement is also shown in Table 5 and seismic
fragility curves of each damage states are also shown in Fig. 4.
According to these results, Table 6 shows the story drift ratios andaverage spectral displacement for each damage states of seismic fragility
function in internal URM buildings. Seismic fragility curve for eachparameter of URM buildings in Korea is as follows as Fig. 5.

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New Technologies for Urban Safety of Mega Cities in Asia

Table 5: Spectral Displacement of Each Damage State
Sm

Mm

Em

Cm

Sd (mm)

8.13

16.51

41.15

96.01

SdH (mm)

14.20

28.72

71.70

164.76

SdH/Sd

1.747

1.740

1.742

1.716

Drift Ratio

0.0024(1/417)0.0048(1/208)0.0120(1/83))

0.0280(1/36)

SdK (mm)

12.10

24.09

40.14

60.11

SdK/Sd

1.488

1.459

0.976

0.626

Drift Ratio

0.0020(1/500)0.0040(1/250)0.0067(1/150)0.0100(1/100)

HAZUS
Applied Story Drift Ratio
for HAZUS

Applied Story Drift Ratio
for Domestic State
Estimation Grade

1.0
0.9
0.8

S_HAZUSM_HAZUSE_HAZUSC_HAZUS

0.7
] 0.6
d
ٛS
ٛ
s0.5
d
>
D
[ 0.4
P
0.3

S_URM(H)
M_URM(H)
E_URM(H)C_URM(H)S_URM(K)
M_URM(K)E_URM(K)C_URM(K)

0.2
0.1
0.0
0

50

100

150
Sd(m m )

200

250

300

Figure 4: Entire Comparison of Seismic Fragility Curve
1.0
0.9

Slight0.8

Moderate

0.7

Extensive

] 0.6
d
ٛS
ٛ
s0.5
d
>
D
[ 0.4
P
0.3

Com plete
SlightModerate
Extensive

0.2

Complete

0.1
0.0
0

50

100

150
Sd(m m )

200

250

300

Earthquake Countermeasures for Safer Future in Korea

275

October 2009, Incheon, Korea

Figure 5: Seismic Fragility Curve for URM in Korea

Table 6: Spectral Displacement and Drift Ratio for URM in Korea

Sd (mm)Drift Ratio

Sm

Mm

Em

Cm

12.10

24.09

40.14

60.11

0.0020(1/500) 0.0040(1/250) 0.0067(1/150) 0.0100(1/100)

4. CONCLUSION
From the capacity spectrum analysis results, spectral displacements for 4
kinds of damage state adopting the suitable drift ratio of damage state in
Korea are suggested, and the seismic fragility function for existing URM
building in Korea is developed.
1) Suitable drift ratio for "Slight", "Moderate", "Extensive" and "Complete"damage state of URM buildings in Korea is suggested.
2) From the capacity spectrum analysis results, spectral displacements for 4
kinds of damage state adopting the suitable drift ratio of damage state in
Korea are proposed.
3) The seismic fragility function for existing URM building in Korea isdeveloped.

REFERENCE
Architectural Institute of Korea, Korean Building Code, 2005. pp. 337-394.
FEMA, 1999. HAZUS99 Technical Manual.
MIDASIT, 2008. MIDAS GEN Ver.741
MIDAS SDS Ver.340
MIDAS GEN Analysis Reference.
NEMA, 2008. Earthquake Disaster Management System.
Kim, J.K., Kim N.H., Ryu, H., Chae, Y.B., 1999. Seismic Response of
Unreinforced Masonry Residuntial Building, Proceedings of EESK
Conference, Vol.3 No. 2, pp. 383-387.
Kwon, K.H., 2001. Development of retrofitting method of unreinforced
masonry structures, University of Seoul, pp. 263.
Guido M. and Gian M. C., 1997. In-Plane Seismic Response of Brick
Masonry Walls, Earthquake Engineering and Structural Dynamics, Vol. 26,
pp. 1091-1112.
Yi, W.H., et al., 2006. A study on a method of the improving the seismic
performance of unreinforced masonry structures and realizing high-risebuildings with using masonry finishing, Construction & Transportation
R&D Report, pp. 216.

276

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 5

INUNDATION PREVENTION
AT THE UNDERGROUND SPACE
IN KOREA
11

GYEWOON CHOI, SEONGJOON BYEON
Department of Civil and Environmental Engineering
University of Incheon, Incheon, Korea
gyewoon@incheon.ac.kr

ABSTRACTIn Korea, localized heavy rainfall frequently happens especially in summer
recently owing to the global abnormal climate. The phenomenon of
subsurface infiltration capacity reduction and direct runoff increase isowing to the economic development plan for industrialization andurbanization in the late 1960s. There is an increase tendency of flood
damage scale and the typhoon Rusa (2002) and Maemi (2003) have cost
about 10,400 billion KRW to recover. This study discusses how to prevent
underground inundation which directly linked with surface inundation andis critical especially in urbanized area with a scope of damage diagnoses,
mitigation strategies and improvement plans. Almost all undergroundstructures have an inundation protection swell installed at the entrance.
However, if a flood depth is higher than the height of swell, inundation ofunderground space is easily happened and hardly recovered because oflower elevation than surface. Therefore, the most important component forprediction and action to mitigate damage is a flood depth at the flooded
area if it is higher than the protection swell and it can be predicted throughflood depth analysis activities such as researching past actual conditions offlood, mapping flood risk and river & coastal flood simulations. Althoughnatural flood risk map should be drawn up in natural disastercountermeasure, the propulsion is still adapting because of insufficientconsist of standard system and inhabitant resistance. To protect people frominundation damage at underground facilities, administrators should
consider for infrastructure safety management practices for user andmeasure for clearway as soon as possible in the expected inundation areas,
when underground facilities were planned and improve the regulations forbuildings. As shown above statements, inundation damage in undergroundis quite serious and complicated due to low elevation, several inlets andhard to be drained. Therefore prevention systems are needed to be
developed so that flood area and depth can be predicted and such as
National Flood Risk Map and related regulations should be improved inflood frequently occurring areas to reduce inundation damages.
Keywords: Underground, Inundation damage reduction, Flood risk map

277

October 2009, Incheon, Korea

1. INTRODUCTION
In Korea, localized heavy rainfall frequently happened recently owing
to the global abnormal climate. The phenomenon of subsurface infiltration
capacity reduction and direct runoff increase is owing to the economic
development plan for industrialization and urbanization in the late 1960s.
There is an increase tendency of flood damage scale. The Rusa typhoon of
2002 and Maemi typhoon of 2003 have cost about 10,400 billion KRW.
Although the loss of lives and property increased during the flood, theinundation precautions are still insufficient. To prevent inundation, thecauses of inundation were analyzed in the underground and presented thedevelopmental tendency in this presentation.
The National Emergency Management Agency (NEMA) under the
Ministry of Government Administration and Home Affairs (MOGAHA)
manages overall measures to counter natural disasters in Korea. From June
1, 2004 the Disaster and Safety Management Basic Law is enacted
designating disaster management competent organizations based on thedisaster definition, identifying the Central Safety Management Committee,
establishing rapid information dissemination system, and enhancing
disaster-related research functions. Disaster Impact Assessment (DIA)
system aims at fundamentally eliminating potential causes of disasters
inherent in various development projects in advance and ultimately
protecting the life and property of the people. This program is one good
example for implementing sustainable development. The disaster impact
assessment system is implemented when the area of targeted development is
not less than 300,000 m2. With respect to small- and medium-sizeddevelopment projects (150,000 m2 to less than 300,000 m2 in size), eachcity and province has introduced a local disaster impact assessment system.
To protect lives and property in downstream areas from the impact of largescale development, facilitating disaster prevention facilities such asretention reservoir in the development area, the DIA has been introduced
since 1996 and the coverage of DIA has been expanded in 2001. Currently,
DIA is applicable to 24 categories in 6 fields such as urban development,
industrial area development, touring attraction development, and mountainarea development.
For feasibility investigation of landslide monitoring and warning
system, analysis of landslide susceptibility using GIS technology isintroduced. Application of GIS technology and determination of affecting
factors are most important aspect of hazard mapping and assessment.
Gangneung City in Gangwon Province has landslide hazard mapping. Sametechniques will be applied to other areas in the near future. Flood hazard
mapping is currently under developing by the Korea Water Resources
Corporation. Korea identified 537 sites most susceptible to inundation,
collapse, and isolation by typhoons and floods, and labeled them as Disaster
Prone Areas. These areas are classified and managed by type, grade,managing entity, size, etc. A total of $1.1 billion will be invested for wide-

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ranging improvements for seven years from 1998 to 2004. Under this plan,$496 million has been invested to improve 488 disaster prone areas from1998 to 2002. Automated high-quality alert facilities, automatic voice
response service regarding the status of disasters and IT system for disasterprevention are in operation. 182 disaster vulnerable areas, which include
river, mountainous valley, etc., have been selected. In stormy weather, thepeople in this area are not allowed to enter and warned to take shelters to
reduce the casualties.
To reduce the loss of life, property damage, and economic hardshipcaused by natural disasters, the Korean government put in practice several
actions. For large scale construction sites, such as subways, golf courses,
dams, and residential development sites, Disaster Preparedness Plans arearranged and maintained, in which assigning multiple government officials
to monitor large-scale construction sites and setting construction priority.
Plans for repairing disaster prevention facilities including retaining walls,
embankments, and reservoirs are established and inspection and repairs forthe facilities are to be completed before the rainy season. Equipment andfacilities for emergency countermeasures have been secured according to
the need averaged over the last ten years and local conditions. For proactive
disaster prevention activities and emergency recovery during severe natural
disasters, the Special Fund has been allocated in 16 cities and 232 districts
since 1997. Small rivers in Korea are vulnerable to overflow. Thus, the firststep of the improvement for vulnerable small rivers is to refurbish from2000 to 2009 at the cost of about $3.9 billion. Since 2002, small river sites
totaling 800km were refurbished at the cost of $32 million, and $11 million
is being invested to 278km in 2002. The Korean government prepares
various disaster prevention plans such as basic and action plans. Basicdisaster prevention plan, which is a long-term plan against disasters
including disaster prevention systems and relevant countermeasures, isformulated every five years. The sixth basic disaster prevention plan iscurrently in effect since 2002. In accordance with basic disaster prevention
plans, specific action plans are formulated and implemented on a yearlybasis by the government.

2. FLOOD DAMAGE SCENARIOS
Recent urban floods such as Seoul flood in Korea in 2001 and 2006
induced inundation into underground spaces such as basements,
underground malls and subways. Underground spaces are located in the
deepest areas of the city, therefore they are very likely to be damaged byfloods, and it is very important to examine inundation flow behavior inunderground space from the hydraulic and disaster preventive aspects.
Regarding these engineering problems, the possibility of evacuation fromunderground space in inundation and necessity of suitable evacuation
system are discussed. In this study both of domestic (5) and overseas (3)severe inundation damage cases were reviewed and summarized bycomparative studies. Major cause of these damages found that swell height

Inundation Prevention at the Underground Space in Korea

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mitigation is more important to protect inflow to the subway from theoverland flow.
2.1 Domestic Flood Damage Scenarios
Underground passage and underground roadway Serious flood
damage caused owing to the uninstalled bump or installed in the lowposition at the entrance of underpass and underground roadway (Fig.1a). A
subway and a railway Damage occurred owing to the insufficient draining
pump, overflowing nearby river and unsuitable drainage inlet design(Fig.1b).

Seoul, 2002

Seoul, 2003

Figure 1a: Domestic Inundation Damage Case (1)Seoul, 2001

Seoul, 2006

Figure 1b: Domestic Inundation Damage Case (2)280

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Underground Shopping Center Serious damages occurred owing to theinsufficient path, unreliable electric equipments, and improper partitions andso on. If inundation occurs the damages become much more serious.
Because population density high in this location (Fig.2.a). Undergroundhouse Damages occur almost every year, especially in the coastal regions
where damages are much worse. Because back water occurred in drain
system due to simultaneous high tide and heavy rainfall (Fig.2.b).

Masan, 2003

Goheung,
2007

Figure 2.a: Domestic Inundation Damage Case (3)Gangwon, 2001

Anyang, 2001

Figure 2.b: Domestic Inundation Damage Case (4)Underground Multistory building It is very difficult to recover the damages
such as in the department stores and large apartments(Fig.2.c).

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October 2009, Incheon, Korea

Anyang, 2001

Masan, 2003

Figure 2.c: Domestic Inundation Damage Case (5)2.2 Overseas Flood Damage Scenarios
In Czech Republic, 2002 subway effected by severe flood damage
lack of drainage inlet, uninstalled bump or installed in the low position at
the entrance of underpass (Fig.3). In England in 2000 and in Mexico in 2007
residential buildings were damaged due to overland flood flow (Fig. 4). In
2007 in England and USA railway was collapsed by flooded water (Fig.5).

Czech, 2002

Czech, 2002

Figure 3: Oversea Inundation Damage Case (1)282

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England, 2000

Mexico, 2007
Figure 4: Oversea Inundation Damage Case (2)England, 2007

USA, 2007
Figure 5: Oversea Inundation Damage Case (2)3.
3.1 Underground Inundation Damage Diagnosis
Damages by increasing inflow water occur due to the bump ofunderground entrance which is lower than flood depth. In the case of
insufficient drain system or by poor maintenance and management,
inundation damages are more serious because water stayed for a long timein the underground facilities. If water is drained through the undergrounddrainage without proper size of water collection tank, serious damages occur
due to decreasing pump efficiency and backwater effect. In the undergroundinstallation, the damage is more serious, when the facilities which arebroadcasting system, light, ventilating holes and so on are insufficient for
shelter.
Inundation damages by stopping drain facilities due to disconnectingfrom electric source causing leakage circuit and blackout, etc. in the

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underground facilities. Flooded water can inflow through the lighting
windows and ventilating holes because they linked on outside and installed
on low position. The damage occurs due to ground water inflow through thewall, roof, and bottom while differential settlement exists on underpass andunderground roadway. Damages which can be overcome occur due toignorance of citizen such as insensibility of safety and negligent education.
Prospective flood depth can be decided with flood depth analysis such as
researching past actual conditions of flood, flood risk map, river flood
simulation and coastal flood simulation. Decision making tools depends on(i) Improving D/B related underground facilities for analysis of actual
condition of past flood, (ii) Compositing national flood risk map andsuggesting the prospected flood depth and (iii) Standardizing the floodmodeling such as river flood simulation, tsunami flood simulation, andregional system development accounts these strategies to diagnosis theunderground damage inundation. .

Figure 6: Standardization of various data system related with disasterprevention and improving related D/B to decide underground inundation
depth

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3.2 Development of National Flood Inundation Risk Map
Although natural flood risk map should be drawn up in natural
disaster countermeasures, the propulsion is still unfinished because of
insufficient consist of standard system and inhabitant resistance. Analyzing
levee overflow, compositing flood map (ex. Han River) required (i)collecting data and site investigation, (ii) flood scenarios, (iii) numerical
map production, DEM, hydraulic and hydrologic analysis, (iv) GIS mappingwith flood depth and inundation area. Compositing numerical flood risk
mapping project guidelines were established by Korean Water Resources
Engineering in 1999 and updated in 2001-2002. Inundation prediction,
catchments modeling and DEM shown in Fig. 7.a. National flood inundation
risk map shown in Fig 7.b by DEM, mesh & 2D drainage basins coupling
model in Fig.7.c.

INUNDA TIO N
PREDIC TIO N

RA INFA LL
RIVER
MO DELINGINPUTC O LLEC TIO N
SYSTEM

BA SIN C HA RA C TERISTIC S

Figure 7.a: Starting the developing project for flood inundation risk map

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1-D Model

Connection

2-D Model

Figure 7.b: Development of National Flood Inundation Risk Map andconnection of 1-D and 2-D Model

Couple2-D Model

Drainage System Model

Figure 7.c: Development of National Flood Inundation Risk Map andconnection of Drainage Catchments and 2-D Model

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Figure 8.a Development of Hazardous Area mappinghFigure 8.b: Development of Flood Depth and Risk mapping

4. THE ESTABLISHMENT OF MEASURES FOR INUNDATIONPREVENTION AND REGULATIONIn the expected inundation areas, when underground facilities wereplanned, administrators should consider for safety for user and measure forclearway as soon as possible. The measure for preventing inundation was
executed step-by- step. The first stage accounts (i) the inundation preventionof underground and the measure for delaying inundation time, (ii) the
number of users for underground and ensures the expected inundation time
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by safe shelter and (iii) to confirm securing the safety of shelter. Second
stage accounts (i) forewarned of inundation dangerousness and execution
instruction, (ii) accurately, rapidly collecting and transmitting flood
information, (iii) the training to prevent the damage from inundation in theunderground space, (iv) to present the plan of a taking shelter from theunderground space and (v) presenting the measure for reducing inundation
damage.
Building construction law must be followed i.e. the sheltering space ofbuilding, supplies restriction, regulation of underground, disastermanagement area and regulation amendment for elevator. According to
Housing construction regulation amendment about construction industry
approval, safety management plan and education (i) regulation of city
planning and underground (ii) the standard of decision about underpass andoverpass road, the standard of installation about the structure of square andpublic areas. Design standard of electric facilities required the improvementof substation facilities, electric wires of underground and management
standard. Design standard of apartment house required the improvement ofelectric devices, installation of IT and security management standard
facilities. Standards for more detailed information that can be used for
installing and operating underground facilities than the existing state should
be provided in order to prevent the damage.
5. CONCLUSION
About 40,000 buildings are damaged owing to localized heavy rainfall
every year. The loss of property has reached 1,200 billion KRW over the
past decade in Korea. Inundation damage in underground is more serious
than surface due to low elevation, several inlets and hard to be drained.
Prevention systems are needed to be developed so that flood area and depth
can be predicted such as National Flood Risk Map. Related regulations
should be improved in flood frequently occurring areas to reduce inundation
damages. Several realistic case studies recommend that these advanced
measures should be account significantly to reduce the flood damages. Thisdevelopment strategy must be functional for disaster preventing aspects.
REFERENCES
Choi, G. W, Lee, H. S, Lee, S. Y, 2007, Urban Inundation Analysis using
the Integrated Model of MOUSE and MIKE21, Journal of Korean Society ofHazard Mitigation Vol. 7 No. 4, KOSHAM
Choi, G. W, Choi, J. Y, Li, J. W, 2003, Reduction Rate of the Total Runoff
Volume though Installing a Rainfall Storage Tank in the Sub-Surface,
Journal of Korea Water Resources Association Vol. 36 No. 3, KWRA
Choi, G. W, Lee, H. S, Ahn, S. J, 1994, Simulation of Moving Strom in a
Watershed using Distributed Models, Volume5, Korean Association of
Hydrological Sciences, pp 1-16

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Ishigaki, T., Toda, K. and Inoue, K., Hydraulic model tests of inundation in
urban area with underground space, Proc. of XXX IAHR Congress, Theme
B, pp.487-493, 2003.
Ministry of Public Administration and Security, 2004, The Research on
Scheme to Prevent Inundation at The Underground Space, MOPAS, Korea.
Smith, G.P. and Carr, R.S., 2004, Linked 2D Overland and 1D Pipe System
Modelling for Urban Flooding. Conference Proceedings, NZWWA
Stormwater Conference, Rotorua, New Zealand.
Toda, K., Kuriyama, K., Oyagi, R. and Inoue, K., 2004, Inundation analysis
of complicated underground space, Journal of Hydroscience and HydraulicEngineering, Vol.22, No.2, JSCE, pp.47-58.

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289

EXPERIMENTAL STUDY
OF MASONRY WALLETTEMADE OF SHAPELESS STONESRETROFITTED BY PP-BAND MESH
1

KOTARO SAKURAI, 2NAVARATNARAJAH SATHIPARAN
and 3KIMIRO MEGURO
1

Graduate Student, Department of Civil Engineering,
The University of Tokyo, Japan
sakurai@risk-mg.iis.u-tokyo.ac.jp
2
JSPS Post Doctoral Fellow, Institute of Industrial Science,
The University of Tokyo, Japansakthi@risk-mg.iis.u-tokyo.ac.jp
3
Director/Professor, ICUS, Institute of Industrial Science,
The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp

ABSTRACT
Unreinforced masonry structure is one of the most popularly used
constructions in the world, especially in developing countries. It is also
unfortunately, the most vulnerable to the earthquake and its damage has
caused many human casualties. Therefore, from global viewpoint,
retrofitting of low earthquake-resistant masonry structures is essential toreduce the casualties significantly from earthquake disaster.
In developing countries, retrofitting method should be technicallyfeasible and economically affordable, the retrofitting material, accessible,
and the workmanship, locally available. Considering these points, PP-band(polypropylene bands, which is worldwide available and cheap material,commonly used for packing) retrofitting technique has been developed andmany different aspects have been studied using brick and adobe masonry
structures by Meguro Laboratory, Institute of Industrial Science, The
University of Tokyo.
In this research, we conducted a series of experiments to verify thesuitability of PP-band retrofitting for masonry structures made of shapelessstones. Material tests were conducted to understand the basic parameters ofstone masonry, i.e. shear, tension and compression strength. After thematerial tests, diagonal compression test and out-of-plane test were carriedout using masonry wallette made of shapeless stones with and without
retrofitting. From both test results, it was clear that PP-band retrofitting
improved drastically the overall stability and ductility of stone masonry
structures made of shapeless stones.

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INTRODUCTION
Masonry structure, constructed by piling burned bricks or unburned, justsun-dried bricks called adobes, stones or concrete blocks, is one of the mostpopularly used constructions in the world, but also most vulnerable to theearthquakes. Because distribution of the masonry structures overlap withhigh seismology area, it has caused many human casualties during
earthquake. Therefore in global viewpoint, retrofitting of low earthquakeresistant masonry structures is very important to save people fromearthquake disaster. Considering these points, a new retrofitting techniquefor masonry has been developed and proposed based on the use ofpolypropylene band (PP-band) meshes by Meguro laboratory. This PP-band
retrofitting technique prevents masonry structures from collapsing by giving
the stabilization.
Up to now PP-band retrofitting study mainly focus on houses build byregularly shaped bricks and adobes. But the masonry has many different
kinds of construction and the effect of PP-band is not confirmed for all
kinds of masonry. Especially in the mountainous region in developing
countries, stone masonry is constructed using shapeless or shaped stones asconstructing material. But stone masonry house, particularly shapeless stone
masonry house is the most vulnerable during earthquake (Table 1).
Therefore further test of stone masonry wallettes should be carried out.
Table 1: vulnerability table (European Macroseismic Scale, 1998)

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2. MATERIAL TEST
2.1

Test setup

Figure 1 shows the specimens used for shear, tension andcompression tests to obtain the mechanical properties of the masonry.
Shapeless stones whose size range from 60mm to 80mm were used forspecimens. A mortar mix of cement: lime: sand = 1: 5: 14 and cement/water
ratio = 0.20 in weight was used. To make the specimens close to real stone
masonry structures made of shapeless stones in developing countries, gravel
were put between the shapeless stones. The number of shapeless stones used
for specimen was 3, 2 and 5 for shear, tension and compression tests
specimen, respectively. Five identical specimens were constructed for eachtest. Specimens were tested 28 days after construction under displacement
control condition and the loading rate was 0.1mm/min.

Figure 1: The structure of the specimens for material test

2.2 Result of material tests
Due to different failure mechanism, major failure patterns of masonrycan be divided into 3 types.
a) Failure occurred within the mortar.
b) Failure occurred along the interface between mortar and stone surface.
c) Failure occurred within the brick or stone.
Only in case of special combination of very strong mortar and very weak
brick or stone, type c) failure can be observed.
From the shear test’s results, it is found that the failure pattern ofmasonry made of shapeless stones is type b) that is the separation along

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interface between stone surface and mortar because interface strength is lessthan that of mortar. Figure 2 shows the average strength of each test, i.e.
shear, tension and compression tests. Figure 3 shows the failure pattern ofstone masonry made of shapeless stones.

Figure 2: Mechanical properties from material tests

Figure 3: Separation along stone-mortar interface

3. DAIAGONAL SHEAR TEST
3.1 Outline of the diagonal compression test
To verify the suitability of PP-band retrofitting technique for stone
masonry, ¼ scaled model diagonal shear test was conducted. The wallette
dimension was 300×300×150mm3 and it was composed of 5 x 3 stones,
and 2 stones in the direction of depth as seen in Figure 4. Because the size

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and shape of stones were variable, there is approximately 10mm variation in
the height of the specimens. Considering the result of material tests, we useda mortar with the mixture ratio of cement : lime : sand = 1 : 7.3 : 18.7 inweight for diagonal shear test to make the specimens close to real masonry
structures made of shapeless stones in developing countries. Cement/water
ratio adopted was 0.15.
In this experimental program, masonry wallettes made of shapelessstones with and without retrofitting were prepared. In addition, specimens
with 10mm surface finishing were prepared. Three identical wallettes wereconstructed for each test. Specimens were tested 28 days after construction,
under displacement control loading condition. The loading rate was
0.5mm/min up to the first 10mm of diagonal deformation, and then it wasincreased to 2mm/min up to 50mm and 5mm/min up to 100mm of diagonal
deformation.

Figure 4: Specimen for diagonal shear test
3.2 Result of the experiment
Figure 5 shows the diagonal shear stress variation with strain for thenon-retrofitted and retrofitted specimens. In the non-retrofitted case, there
was no residual strength after first crack occurred and the specimens split
into two pieces at strain equal to 1.1%. In the retrofitted case, although theinitial crack was followed by a sharp drop, at least 64% of the peak stressremained. Subsequent drop were associated with new cracks such as the one
observed at the strain of 2.5%. After this, the stress was regained byreadjusting and packing by PP-band mesh. The stress equal to 72% and 81%of the initial peak stress was remained at the strain equal to 10% and 20%
respectively. The residual peak stress of the specimen was 99% of initial
peak stress. Specimen didn’t break at the strain equal to 24%, whichindicate that; retrofitted specimen was at least 21 times more ductile than
non-retrofitted one.

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October 2009, Incheon, Korea

Figure 5: Stress vs. strain for stone masonry wallettewith and without retrofitting by PP-band mesh
Figure 6 shows the non-retrofitted and retrofitted specimens at theend of test, which corresponded to strain equal to 1.1% and 24%
respectively. As strain became larger, due to very low mortar strength, PPband was penetrated to the specimens. Therefore, increase of strength was
not observed with strain. However, for specimens used for 1/4 scaled
experiment, scaled PP-band which width was approximately 6mm was used
and it was increased penetration-rate. But in case of full scale, 15mm PPbands will be use, penetration of PP-band mesh to the masonry houses will
be reduced relatively. Therefore additional increase of strength will be
expected, when retrofitting the real scale masonry structures by PP-bandmeshes.

Figure 6: Failure pattern of stone masonry wallette(Left: without retrofitting, Right: with retrofitting)Figure 7 shows the diagonal shear stress variation with strain for
retrofitted and retrofitted specimen with surface finishing. In this case,296

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surface finishing on specimens applied by mortar mix with the width of
10mm was used. In case of retrofitted specimen without surface finishing,
64% of the peak stress was remained after first crack. On the other hand,
retrofitted specimen with surface finishing, 77% of the peak stress wasremained after first crack. By overlaying mortar onto PP-band mesh, surface
finishing fill the gap between PP-band mesh and masonry wallette and theresidual strength was higher than the specimens without surface finishing. It
was found that surface finishing makes beneficial effect in residual strength
for masonry made of shapeless stones as well as for adobe and brick.

Figure 7: Stress vs. strain for retrofitted stone masonry wallettewith and without surface finishing

4. OUT-OF-PLANE TEST
4.1 Outline of the out-of-plane test
Out-of-plane test was carried out to investigate the effectiveness of
PP-band mesh in walls exhibiting arching action. Wallette used was 1/4
scaled model and its dimension was 480 × 240 × 150mm3 and it wascomposed 4 x 5 stones, and 2 stones in the direction of depth as seen in
Figure 8. Because the size and shape of stones were variable, there is theapproximately 10mm variation in the height of the specimens. Considering
the result of material tests, we used a mortar with mixture ratio of cement :lime : sand =1 : 4 : 11.2 in weight for out-of-plane test to make thespecimens close to real masonry structures made of shapeless stones indeveloping countries. And also, not to give damage to the specimen before
test, the cement/water ratio used was 0.25.

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Masonry wallettes made of shapeless stones with and without
retrofitting were prepared and three identical wallettes were constructed foreach test. Specimens were tested 28 days after construction underdisplacement control loading condition. The wallettes were simply
supported with a 440mm span and steel rods were used to support thewallette at the two ends. The masonry wallettes were tested under a line
load which was applied by a 20mm diameter steel rod at the wallette mid
span. The loading rate was 0.5mm/min for the first 6mm of verticaldeformation, and then it was increased to 2mm/min up to 65mm verticaldeformation.

Figure 8: Specimen for out-of-plane test

4.2 Result of the experiment
Figure 9 shows the out-of-plane load variation with net verticaldeformation for the non-retrofitted and retrofitted specimens at the mid span.
In the non-retrofitted case, the initial strength was 1.34 KN and thespecimens split into two pieces at the mid span deformation equal to 1.4mm.
While in the retrofitted case, although the initial crack was followed by a
sharp drop, at least 33% of the peak strength remained. After this, thestrength was regained progressively due to the PP-band mesh effects. The
strength equal to 225% and 433% of the initial peak strength was observedat the mid span deformation equal to 20mm and 40mm, respectively. The
residual peak strength of the specimen was 439% of initial peak strength.
Specimen didn’t break at the mid span deformation equal to 62mm, whichindicates that; retrofitted specimen was at least 45 times more ductile than
non-retrofitted one.

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Figure 9: Out-of-plane load variation vs. vertical deformation
Figure 10 shows the non-retrofitted and retrofitted specimens at theend of test, which corresponded to deformation equal to 1.4mm and 62mm,
respectively. In out-of-plane test, the improvement of final strength becamemuch bigger than that of diagonal compression test. The cement/water ratioof the specimens used for the diagonal shear test was 0.15, but in case ofout-of-plane test, the cement/water ratio equal to 0.25 was used. Because
strength of mortar is high enough, PP-band didn’t penetrate to thespecimens and the drastic improvement of residual strength was observed.

Figure 10: Failure pattern of stone masonry wallette(Left: without retrofitting, Right: with retrofitting)

5. CONCLUSIONSThis paper mainly discusses the result of a series of diagonal compression
tests and out-of-plane tests that were carried out using both non-retrofitted
and retrofitted wallettes by PP-band meshes.

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5.1 Summary of diagonal compression test
1. Masonry wallette without PP-band mesh lost the entire load bearing
capacity after crack appeared.
2. Masonry wallette with PP-band mesh retrofitting lost some of load
bearing capacity immediately after the crack-initiation, but 64% of
the peak stress was remained. With the effects of the PP-bandmeshes, it could regain the load bearing capacity, and its strengthand deformability improved. According to the experimental result,
1.3 times higher peak stress and at least 21 times larger ductility
were observed.
3. By overlaying mortar onto PP-band mesh retrofitted masonrywallette, 77% of the peak stress was remained after first crack. It
was relatively higher than that of the specimens without surface
finishing.
5.2 Summary of out-of-plane test
1. In case of out-of-plane tests, the mesh effect was not observed
before the wall cracking. After cracking, the mesh presence
positively influenced the wallette behavior. Also in case ofretrofitted wallette, 33% of the peak strength was remained after first
crack occurred, and then strength was regained and improved.
2. The retrofitted wallettes achieved 2.9 times higher strength and 45
times larger deformation than those of the non-retrofitted ones.
Considering the overall performance of the specimens, we can conclude
that PP-band mesh retrofit method can effectively increase the seismic
capacity of masonry wall made of shapeless stones, too. Based on the fact,
we can expect that with PP-band mesh retrofit method, seismic capacity of
weak stone masonry houses made of shapeless stones can also be improved
very much.

REFERENCES
Paola MAYORCA and Kimiro MEGURO, 2004. Proposal of an EfficientTechnique for Retrofitting Unreinforced Masonry Dwellings.
Proceedings of 13th World Conference on Earthquake Engineering,
Vancouver B.C., Canada, Paper No.2431.
Navaratnarajah
SATHIPARAN,
Paola
MAYORCA,
KouroshNasrollahzadeh NESHELI, Ramesh GURAGAIN and Kimiro
MEGURO, 2005. Experimental Study on In-plane and Out-of-plane
Behavior of Masonry Wallettes Retrofitted by PP-band Meshes,
SEISAN-KENKYU 57, pp.530~533.
Marjana LUTMAN. STONE MASONRY CONSTRUCTION (www.worldhousing.net), as retrieved on April 1st , 2009.
Navaratnarajah SATHIPARAN, 2005. Experimental Study of Retrofit of
Masonry Buildings by PP-band Mesh, M.Eng. Dessertation, The
University of Tokyo, Japan.

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SHEAR STRENGTHENING OF
REINFORCED CONCRETE BEAMSUSING FERROCEMENTPRAGASIT JUNTANALIKIT
Sirindhorn International Institute of Technology,
Thammasat University, Pathumthani, Thailand
pj_bank2@hotmail.com
PANUWAT JOYKLAD
Sirindhorn International Institute of Technology,
Thammasat University, Pathumthani, Thailand
joy.civil@gmail.com
AMORN PIMANMAS
Sirindhorn International Institute of Technology,
Thammasat University, Pathumthani, Thailand
amorn@siit.tu.ac.th

ABSTRACTThe methods for strengthening rectangular reinforced concrete beams
using ferrocement attached onto the surface of the beams are described inthis paper. The study is based on an experimental program carried out on 5
beams designed to fail in shear mode. One of them is control specimen andthe others are strengthened by various ferrocement techniques. In thesetechniques, two centimeter thick ferrocement jacket is used together withadditional external web reinforcement. The difference among each specimen
is the installation method, shape of ferrocement jacket, spacing ofadditional external web reinforcements and surface roughness between
original beam and ferrocement cover. Results from tests, such as ultimate
strength, ductility and cracking pattern, of strengthened specimens arecompared with control specimen. Load-deflection responses are obtained up
to failure or reach the capacity limit of measuring devices, and theperformance of the various proposed methods are compared withconventional ACI procedure. The effect of various parameters, such as
shape of ferrocement cover, spacing and configuration of external web
reinforcements and surface roughness are considered. Results show that the
proposed strengthening method provides better ductility, ultimate strengthand mode of failure. Therefore, it is found that the proposed shear
strengthening method is very effective and strongly confirms thatferrocement is a viable alternative material for strengthening reinforced
concrete structure.

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October 2009, Incheon, Korea

1. INTRODUCTION
The market for maintenance and repairing existing structures has beenenormous in the past years, due to the deterioration and/or the requirementson the existing structures to carry more loads. Of the various retrofitting
techniques available, steel plate bonding is one of the most effective andconvenient methods of strengthening. Ferroceemnt jacketing is found to be
one such attractive technique due to its properties such as good tensile
strength, light weight, overall economy and water tightness. The skeleton
steel combined with ferrocement cover is one of several suitable choices foruse in developing country. Ferrocement is a type of thin composite material
made of cement mortar reinforced with uniformly distributed layers ofcontinuous, relatively small diameter, wire meshes and skeleton steels.
Originally, ferrocement materials were used only in housing applications.
However, during the last two decades, the applications of ferrocement in thefield of repair and strengthening have been developed rapidly. Ferrocement
construction requires conventional technology and offers better performanceeven when handled by less experienced workers.
Many experimental studies have been conducted in recent years to increase
flexural capacity. Paramasivam et al. reported the test of six simplysupported inverted T-beams under static and cyclic loads applied at midspan. The results show that the beams were substantially strengthened andstiffened with the provision of additional stirrups and wire meshes in the
thickened sections encasing the beams’ web and the tension face.
Rafeeqi et al. tested five reinforced concrete beams designed to fail in brittle
shear-compression. The strengthened beams showed a marked improvementin performances at service load, greatly improved ductility at ultimate loadwith either a ductile shear failure or seemingly a transition from shear to theflexural mode of failure.
However, the research on using ferrocement to increase shear capacity has
been limited. In this paper, the authors apply the combined use of external
skeleton steel and ferrrocement cover for shear strengthening of reinforced
concrete beam. The proposed method focuses on strength and ductility. The
simple calculations recommended by ACI code are also compared withtested results in order to guide the designers.

2. EXPERIMENTAL PROGRAM
The simply supported reinforced concrete beams with four-point bending
was tested in this study. Five identical beams were strengthened by different
techniques using external skeleton bars and ferrocement cover. The crosssection was 200 mm wide and 300 high. The total length was 2400 mm andthe effective span was 2200 mm. The beams were designed to fail in shear
failure. The nominal moment capacity to nominal shear capacity ratio,

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Mn/(aVn), and shear span-to-effective dept ratio, a/d, was greater than 1.2
and less than 3.0, respectively. The details of material properties and test set
up are explained in the next section
2.1 Material Properties
The beams reinforced with four bars of 20 mm diameter in tension andtwo bars of 12 mm diameter in compression were cast using the same batchof ready mix concrete. The transverse reinforcements consisted of RB6 bars
spaced at 125 mm center to center. The tested yield and tensile strength ofreinforcements were given in Table 1.

Diameter
(mm.)
20
12
9
6

Table 1: Mechanical property of rebar
Tensile strength
Yield strength
Grade
(MPa)
(MPa)
SD30
347.13454.81SD40
479.19605.90SR24341.20471.24SR24
406.61511.85Hexagonal wire mesh was used for ferrocement. The mortar mix is
made of 1:1.8 cement sand mortar and w/c ratio 0.40 by weight. The
average cylindrical compressive strength of concrete was given in Table 2.
Table 2: Mechanical property of concrete
Specimensf’c (MPa)f’m (MPa)
CON
20.40
S200
23.05
48.74
S200SR
23.64
48.75
S200CL
23.54
48.75
U200
23.54
48.35
The average 50 mm x 50 mm x 50 mm cube strength of mortar was 49
MPa. The average tensile force of mortar was found to be 4.71 kN by direct
tensile test using 20 mm x 100 mm specimen as shown in Figure 1.

Figure 1: Direct Tensile Test of pure mortar and ferrocement specimen
2.2 Strengthening techniques
Out of the five beams, one was used as control beams (CON). The
S200 specimen was strengthened by ferrocement attached onto the both side
Shear Strengthening of Reinforced Concrete Beams using Ferrocement303

October 2009, Incheon, Korea

surfaces of the beam. Before the 20 mm thick ferrocement panels wereplastered onto beam, the beam was predrilled by an augur on both sides. The
spacing of the holes was 200 mm which was the spacing of additional
external web reinforcements (Table 3). Next, the prefabricated skeleton steel,made from RB6 with 2 layers of wire meshes, was attached onto beam faces.
Then, RB9 reinforcing bars that had been bent in C-shape were inserted intoholes and fixed with beam via chemical epoxy as shown in Fig. 2.

Specimens
CON
S200
S200SR
S200CL
U200

Table 3: Description of specimens
Spacing of Main
Special Detail
additional rebars (mm.)
200200Surface roughening
200
extra clip reinforcements
200-(a) C-shaped reinforcement (b) Plastering (c) Finishing the surface(external web reinforcement)
Figure 2: Construction procedure for specimen S200.
Specimens S00SR and S200CL had the same properties as S200 withsome modifications. For S200SR, the surface of the original beam wasroughened by chisel to increase the bonding with ferrocement covers (Fig. 3(a)).
To reduce the cost of drilling hole and epoxy and save theconstruction time and labor, specimen S200CL, with 200 mm c/c spacing ofC-shaped reinforcements, was also provided with additional C-clip steels
spaced at 200 mm. It should be noted that the C-clip steels were not inserted
into the drilled hole. In effect, the spacing of external reinforcements in
S200CL was 100 mm c/c (Fig. 3 (b)). For specimen U200, the beam wascovered with ferrocement panel on the side face as well as the bottom face
(U-shape). The RB9 external web reinforcements were bent in U-shape asshown in Fig. 4(a). The spacing of these reinforcements was 200 mm.

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(a) Increase the surface roughness (b) Extra C-clip steel for S200CL
for S200SR
Figure 3: Construction Techniques for specimens S200SR and S200CL(a) U-shape external web
reinforcements(b) Installing U-shape bars andskeleton steel(c) Plastering mortar at the(d) Finishing the surface
bottom face
Figure 4: Construction Techniques of specimen U200

Figure 6: Test Setup and loading
Details

Figure 5: Details of specimens
Shear Strengthening of Reinforced Concrete Beams using Ferrocement305

October 2009, Incheon, Korea

Figure 5 shows details of the five beams together with specimen
designation. It shall be noted that ferrocement cover was not patched for thefull depth of the beam, but the clear distance of 10 mm offset from theloading face of beam was provided to prevent any non-uniform contact
between load and the ferrocement cover. Table 4 shows the calculated shear
and flexural capacity and the failure mode of the beams.
2.3 Testing Arrangement
All five beams were tested using hydraulic jack mounted verticallyover the test beams. Two concentrated loads were applied at 700 mm
spacing (see Figure 6) in a four-point bending layout. The specimens were
tested using a strong steel frame. The specimens are supported by roller andpin support on each end. In the first stage, before reinforcements reached theyield strength, specimens were tested under load control with monotonicallyincremental load of 10 kN for each load step.
After reinforcements reached the yield strength, specimens were tested
under displacement control with monotonically incremental displacement of
one mm for each step. The deflection of the beam was measured using
displacement transducers placed at mid span and at the location of distributedload. The strain gauges were attached to the main reinforcing bars, transverse
reinforcing bars and additional external transverse reinforcing bars.
3. RESULTS AND DISCUSSION
Figure 7 shows the load versus deflection behaviour at the mid span of thetested beams. The experimental results are summarized in Table 5, as wellas the failure patterns shown in Figure 8. It is observed that the control
specimen that was designed to fail in shear reached the maximum load whena large single shear crack developed. The other specimens demonstrated
dramatic improvement in shear capacity.
300

250

Load (kN)

200

150

CON
S200

100

S200SR
50

S200CL
U200

0
0

10

20

30

40

50

60

Displacement(mm.)

Figure 7: Load-displacement curve for all test specimens

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Code
CON
S200
S200SR
S200CL
U200

Table 4: Specimen sectional force properties
Mn
Vn
Pp
Mn/(aVn)predict(kN-m)
(kN)
(kN)
89.28
86.73
1.37
173.4694.93
147.340.85
253.1494.93
147.830.85
253.1494.93
182.950.69
253.1495.54
149.600.85
254.77

Failure(Predict)
Shear
FlexureFlexureFlexureFlexureTable 5: Result of experiments
Code
CON
S200
S200SR
S200CL
U200

Pt
Tested (kN)

Pp/Pt

Ductilit
ratio

147.40239.20249.40241.95254.75

1.17
1.05
1.01
1.04
1.00

1.39
1.71
1.64
2.83
2.60

Failure(Tested)
Shear
Shear
Flexure/shear
FlexureFlexureThe mode of failure in most specimens changed from shear to flexure. Only
specimen S200 failed in combined shear and flexure. Nevertheless, allspecimens show significant increase in load capacity. U200 shows the samelevel of strength enhancement as S200, but the failure of U200 is flexural
failure which is different from shear failure of S200. As shown in Table 4,
the ductility ratio of U200 is 2.60, which is higher than specimen S200.
Consequently, the U-shaped ferrocement has certain benefits compared withside ferrocement.
In order to increase bonding between surfaces of two materials, theroughness between original beam and ferrocement cover was increased byroughening the surface of the original beam. The effect of surface roughness
can be evaluated by comparing the result of S200 and S200SR. The
maximum load capacity is almost the same for both specimens but theductility of S200SR is larger.
To prevent the shear failure in S200, specimen S200CL was provided withextra clip reinforcements attached on the surface of the beam. It is noted thatthe extra clip reinforcements are not fixed into the holes. As a result, there is
no extra cost of drilling hole and adhesive. As shown, the specimen shows
better performance as compared with S200 and S200SR. The failure modeis flexural failure with large ductility.

Shear Strengthening of Reinforced Concrete Beams using Ferrocement307

October 2009, Incheon, Korea(a) CON(b) S200(c) S200SR(d) S200CL(e) U200
Figure 8: Crack pattern at failure of specimens

4. PREDICTION OF CAPACITY USING ACI CODE
In order to predict the capacity of strengthened beams, the generalprocedure of ACI318 had been adopted and modified to analyze beams withferrocement cover.
4.1 Ultimate Moment Capacity
The theoretical ultimate moment capacity of the composite beam
sections was calculated by means of the conventional reinforced concrete
theory. The compressive force contributed by concrete was calculated basedon simplified stress block proposed in ACI318. The influence offerrocement in the compression zone was omitted. The tensile forces of thesection were contributed by tension steels and ferrocement tensile force. In
this case, ferrocement tensile force was previously obtained via tensile testof ferrocement panels. The compression forces acting on the section can be
expressed as,308

New Technologies for Urban Safety of Mega Cities in Asia

C  0.85 f cab   Asc f y(1)

The total tensile forces in the tension zone can be expressed as,T   Ast f y  T f

(2)

where
f c = compressive strength of concrete, (MPa)f y = tensile strength of steels, (MPa)T f = tensile force of ferrocement, (N)2

Ast = tension steel area, (mm. )a = depth of compressive stress block, (mm.)
b = section breadth, (mm.)

Based on equilibrium of forces on the section, the depth ofcompressive zone can be determined. The moment capacity can then becomputed as the product between either tension or compression force andmoment arm. Figure 9 shows the equilibrium of forces on the composite
beam section.
0.85 f c

As

As

fy

a

fy

f

Cc  C sMn

Ts
Tf

ferrocement cover

Figure 9: Stresses and forces on the section
4.2 Shear Strength

The shear strength of concrete section was evaluated using ACI318
simplified equation.
Vc  (1 / 6) f cbd

(3)

The shear strength contributed from mortar was ignored. Additional,
shear strength contributed by internal and external web reinforcements werecomputed by conventional formula.
Vs 

Av f y ds(4)Shear Strengthening of Reinforced Concrete Beams using Ferrocement309

October 2009, Incheon, Korea

whered = effective depth, (mm.)
s = spacing of web reinforcements, (mm.)
The comparison of failure load using ACI procedure is shown in
Table 4 and Table 5. A good agreement is obtained except specimen “con”
in which the ACI code seems to give higher load compared with the test
result.

5. PRACTICAL APPLICATION OF THE METHOD

Based on the results of the testing program, the proposed method has been
applied in real building. The 20 year old three-story residential house wasstrengthened in shear by ferrocement cover with additional web
reinforcements. The side cover method was applied to the edge beam while
the U-cover method was applied to the intermediate beams. The contractor’sopinion was that this strengthening method offered lots of advantages interms of fast time construction, low budget, low labor demand and easy
constructability. Figure 10 shows the real application in the field.

(a) Side-cover was applied
for edge beams(b) Finishing the surface(c) U-cover was applied
for intermediate beams(d) Finishing the surface

Figure 10: React application in the field

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New Technologies for Urban Safety of Mega Cities in Asia

6. CONCLUSIONS

Based upon the test results of the experimental, five reinforced concretebeams were tested under monotonic loading. The main parameters are theshape of ferrocement cover, surface roughness and extra clip reinforcement.
From these experiments, the following conclusions can be drawn.








The failure of strengthening beam is developed by flexural crack incompressive zone.
The capacity of strengthened specimens increased approximately
70% compared to the control specimen.
After strengthening, all of beam showed large deflection at ultimate
load.
Using special C-clip bars can save the construction times, prevent
shear failure and gain more ductility.
The surface roughness can increase ductility.
The specimen with U ferrocement cover has higher load carrying
capacity, preventing shear failure, and larger ductility compared withspecimens strengthened by side cover ferrocement.
The conventional ACI method can be adopted for strengthening
design purposes.

7. ACKNOWLEDGEMENTS

The authors are very grateful to Thailand Research Fund (TRF) for
providing the research fund RSA S280034 to carry out the research.

REFERENCES

P. Joyklad, T. Pheeraphan, and P. Nimityongskul, Development of
Ferrocement Panel to Resist Blast Load, The 10th National Convention on
Civil Engineering, Chonburi, May 2-4, 2005.
A. W. Anwar, P. Nimityongskul, R. P. Pama and Robler-Austriaco, Methodof Rehabilitation of Structural Beam Elements Using Ferrocement, Journalof Ferrocement, Vol. 21(3), 1991.
K. C. G. Ong, P. Paramasivam and C. T. E. Lim, Flexural Strengthening ofReinforced Concrete Beam Using Ferrocement Laminates, Journal of
Ferrocement, Vol. 22(4), 1992.
M. Z. Jamin and M. A. Alam, Flexural Strengthening of Reinforced
Concrete Beams Using Ferrocement Laminate with Skeleton Bars, Journalof Applied Sciences Research, Vol. 2(9), 2006.
H. F. Ezzat, B. I. S. Yousry and S. K. Yasser, Repairing Reinforced
Concrete Beams by Ferrocement, Journal of Ferrocement, Vol. 27(1), 1997.
P. Paramasivam, C. T. E. Lim and K. C. G. Ong, “Strengthening of RC
Beams with Ferrocement Laminates”, Cement and Concrete Composites,
Vol. 20, 1998.

Shear Strengthening of Reinforced Concrete Beams using Ferrocement311

October 2009, Incheon, Korea

S. F. A. Rafeeqi, S. H. Lodi and Z. R. Wadalawala, Behavior of Reinforced
Concrete Beams Strengthening in Shear, 7th International Symposium on
Ferrocement and Thin Reinforced Concrete Composites, National
University of Singapore, June 27-29, 2001.
ACI318-99, Building Code requirements for structural concrete andcomplementary. American Concrete Institute, Farmington Hills, Michigan,
1999.

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A STUDY ON SEISMIC REPAIR COST OF
R/C BUILDING STRUCTURES USINGA GEOMETRICAL DAMAGE ESTIMATIONMODEL OF R/C MEMBERSNORIYUKI TAKAHASHI
Institute of Industrial Science, The University of Tokyo, Japanntaka@iis.u-tokyo.ac.jp
YOSHIAKI NAKANOInstitute of Industrial Science, The University of Tokyo, Japaniisnak@iis.u-tokyo.ac.jp

ABSTRACTTo evaluate visible damage of reinforced concrete (R/C) members
such as crack width and length, cyclic load tests of one third scaled R/Cmembers were carried out. Based on the tests, a geometrical damage
estimation model is proposed to quantify each crack width andcorresponding length. The model consists primarily of a geometricalcondition for the relationship between the sum of crack widths and drift
ratio and a probabilistic model between crack widths and lengths.
Applying the proposed model to seismic response analyses of R/Cbuilding structures modeled as fish-bone shaped frames, the damage andrepairing process, as well as life cycle economic loss were simulated. Life
cycle economic loss was defined here as the repairing cost for maintenanceof the functionality of a building through its life length. As a result, it is
implied that the case of main damages on beams will suffer more life cycle
economic losses than the case of main damages on columns because of theextent of damaged area and the construction cost of falsework.

1. INTORODUCTION
Loss estimation of a building due to earthquake events in its life length isimportant to facilitate the decision making of the building owner to choose
the reasonable seismic performance. In this paper, life cycle economic loss
defined as the repairing cost of a building structure through its life length
was simulated using a new damage estimation model which is partiallybased on cyclic load tests of one third scaled R/C members.

2. EXPERIMENTAL PROGRAM
2.1 Test specimens, setup and instrumentation
Two R/C beam specimens proportioned to approximately 1/3 of full313

October 2009, Incheon, Korea

scale were tested under cyclic loading. The design parameters andcorresponding values are given in Table 1. The dimension for the test
specimens and test setup are shown in Figure 1. To obtain the propagationof crack width and length corresponding to attained and present drift ratio,
the cyclic displacement pattern shown in Figure 2 was operated. Crackwidths were measured at the points shown in Figure 3 by crack gauges.
Crack lengths were measured by image processing of sketched and scanned
cracking pattern.
Table 1: Description of Test Specimens
Rebar
Concrete
TensileSpecimen Strength
reinforcement(N/mm2)
ratio to thesection
8-D13
F-1
30
S-1
18
0.0121

Yield
strengthof rebar(N/mm2)295
785

LateralYield
reinforcement
strength
Failureof lateral
mode
Lateralreinforcement
reinforcement2(N/mm )
ratio to the section
D4@60
295
Flexure295
Shear0.0022

Figure 1: Dimension of Beam Specimen and Test Setup

Figure 2. Cyclic Displacement PatternFigure 3: Crack Measurement Point

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New Technologies for Urban Safety of Mega Cities in Asia

2.2 Test results
Figure 4 shows the shear force versus drift response for each specimen andthe cracking pattern at 4.0% drift. Measured maximum and average crack widths
are shown in Figure 5. Measured crack lengths are shown in Figure 6. Crack widthand length of specimen S-1 increased rather than specimen F-1 in large drift.

Figure 4: Shear Force versus Drift Ratio Response, and Cracking PatternFigure 5: Crack Width for Attained Drift Ratio

Figure 6: Crack Length for Attained Drift Ratio

3. GEOMETRICAL DAMAGE ESTIMATION
3.1 Geometrical damage estimation model
Architectural Institute of Japan (AIJ, 2004) proposed geometricalmacro model of relation between crack width and drift ratio shown in Figure
7. In this paper, this relation is expressed as
A Study on Seismic Repair Cost of R/C Building Structures Using A Geometrical Damage Estimation Modelof R/C Members

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October 2009, Incheon, Korea

R = R f + Rs =∑ w + 2∑ w ⋅ cosθfs

D − xnL(1)where, Rf: flexural drift ratio, Rs: Shear drift ratio, wf: flexural crack width,
ws: shear crack width, D: depth, xn: distance from extreme compression fiber
to neutral axis, and L: clear span, respectively. CEB-FIP (1978) proposedcrack spacing shown in Figure 8. Crack length at stabilized crack pattern
due to Figure 8 is expressed aslav , f =l av ,s =ζ ⋅ L ⋅ ( D − xn )

(2a)

S av

⎞ q ⋅ (q + 1) ⋅ S av
D ⎛ D cosθ + L sin θ⎜− 2q ⎟⎟ +S av
sin θ ⎜⎝sin θ cosθ⎠

(2b)where, lav,f: stabilized flexural crack length, lav,s: stabilized shear crack
length, Sav: crack spacing, θ: crack angle, and q: quotient of Dcosθ / Sav,
respectively.

Figure 7: Geometrical Model between Crack Width and Drift(a) Flexural crack spacing(b) Shear crack spacing

Figure 8: Crack Spacing

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Estimation results of crack width of specimen F-1 and S-1 due tothis geometrical model are shown in Figure 9 and 10, respectively. The
estimated crack width of specimen F-1 can approximately simulate theexperimental result. On the contrary, that of specimen S-1 canapproximately simulate the experimental result only at the unloaded drift,
and it overestimates at the peak drift and underestimates at the zero-residual
drift. It implies that the geometrical model shown in Figure 7 matches up
with the unloaded drift condition. In the after-mentioned study on life cycle
economic loss estimation, the residual drift after excitation is supposed to be
similar to the unloaded drift, and it is assumed that the crack width can becalculated from the residual drift after excitation with the geometrical model.

Figure 9: Crack Width Estimation of Specimen F-1
Exp. max crack width(at flexual crack)Exp. max crack width(at shear crack)
Calc. max crack width(at flexual crack)
Calc. max crack width(at shear crack)

peak
peak
peak
peak

unloadunloadunloadunloadzero-residual
zero-residual
zero-residual
zero-residual

Figure 10: Crack Width Estimation of Specimen S-1
Estimation results of crack length of specimen F-1 and S-1 due tothe geometrical model are shown in Figure 11. The estimated crack length
represents essentially the length at stabilized crack pattern, thus the
propagation of crack length can not be expressed. Based on Figure 11, a
new crack length propagation model is proposed in Figure 12. In Figure 12,
β means the ratio of flexural drift to total drift. In the after-mentioned study
on life cycle economic loss estimation, it is assumed that the clack length
can be calculated from the attained maximum drift with the geometricalmodel.
A Study on Seismic Repair Cost of R/C Building Structures Using A Geometrical Damage Estimation Modelof R/C Members

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October 2009, Incheon, Korea

Figure 11: Crack Length Estimation

Figure 12: Crack Length Propagation Model
Additionally, the spalling propagation model based on previous
research (Takahashi, 2005) shown in Figure 13 is proposed, though it
depends not on the geometrical model but on the empirical model. It is
formulated as
SR = αsp×(IDRmax − R0)(3)

where, SR: spalling ratio [m2/m2], αsp: constant value (= 3.67), R0: initial
spalling drift ratio (= 0.01), and IDRmax: attained maximum drift ratio.

Figure 13: Spalling Propagation Model
3.2 Probabilistic model between crack width and length
A new probabilistic model between crack widths and lengths is also
introduced. Crack length distribution to crack width is represented as lognormal distribution in this proposed model. Figure 14 shows the crack

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length distribution histogram at the drift of +0.01 rad. Comparing the
calculated results with experimental results, the crack length distribution ofboth specimen can be simulated by log-normal distribution with standard
deviation σ = 3.0. As concern with the standard deviation, the different
values, σ = 0.22~1.49, were proposed by other researchers (Takimoto et al.,2004 and Igarashi et al., 2009). It means that the standard deviation of crack
length distribution is unstable. In the after-mentioned study on life cycle
economic loss estimation, the standard deviation is assumed to be 1.1.

Figure 14: Crack Length Distribution to Crack Width (at +0.01 rad.)4. LIFE CYCLE COST ESTIMATION
4.1 Input ground motion
To estimate the lifecycle economic loss, the scenario of earthquake
events through lifecycle is necessary, then peak velocities of ground motion
on engineering bedrock are firstly calculated based on the seismic hazard
curve proposed by National research Institute for Earth science and Disasterprevention (NIED, 2005). Secondly, a series of peak velocities on themedium soil through lifecycle is created such that they fit the probabilistic
distribution using the plotting position equation. Plotting position equationis represented by
F ( x) =i−α
N + 1 − 2α(4)where, N: total number of years in record, i: rank in descending order (i.e.
from highest to lowest), x: value of ith data, F(x): exceedance probability andα: constant value. α is calculated as Equation 5 to define the probability ofexceedance for the largest earthquake as P(i)% in lifecycle years,α=( N + 1) ln(1 − P(i)) + iT
2 ln(1 − P(i)) + T(5)where, P(i): ith data’s probability of exceedance in T years. The sequence ofearthquake is rearranged in a random order. This series of peak velocity is
A Study on Seismic Repair Cost of R/C Building Structures Using A Geometrical Damage Estimation Modelof R/C Members

319

October 2009, Incheon, Korea

used as a target to modify an input base accelerogram. Figure 15 shows theseismic hazard curve in Tokyo proposed by NIED (NIED, 2005). Figure 16
shows the example of lifecycle peak ground velocities on the medium soil inTokyo in the case of 50 years life length and 10% in 50 years as theprobability of exceedance for the largest earthquake.

Figure 15: Hazard Curve in Tokyo Figure 16: Example of Life Cycle PGV
4.2 Structural modelTwo fishbone-shaped frames shown in Figure 17 are studied for
estimating the life cycle repair cost. One is strong-column and weak-beamframe with beam rebar strength σs=390kN. Another is weak-column andstrong-beam frame with beam rebar strength σs=490kN. Takeda hysteresis
model (Takeda et al. 1970) is used for each member modeled as onecomponent model. Viscous damping factors proportional to instantaneous
stiffness are assumed to be 3%. The cracking strength is assumed to be one
third of yielding strength, the secant stiffness at yielding point is assumed to
be 30% of the linearly elastic stiffness, and the third stiffness after yielding
is assumed to be 1% of the linearly elastic stiffness for each member.

Common Variable:
Mass : 1.2 tonf/m2
Column : 700×700 (Fc32, 8-D32/ σs=390kN)
Beam : 400×800 (Fc24, 8-D25/ σs=*)Footing : 600×1800 (Fc32, 12-D32 / σs=390kN)*Analytical Parameter:(a) Strong-column and weak-beam type
Beam rebar strength: σs=390kN(b) Weak-column and strong-beam type
Beam rebar strength: σs=490kN

Figure 17: Structural Model
4.3 Calculation results of life cycle economic loss
Providing the maximum drift ratio is larger than yielding drift(assumed to be 1/120 rad. in this study), structures are repaired according to320

New Technologies for Urban Safety of Mega Cities in Asia

the scenario described in Table 2. If the maximum displacement is smaller
than yielding drift, structures are left unrepaired with damage such as a
stiffness degradation. Estimated life cycle economic losses of two structures
defined as the repairing cost of structures through their life length are shownin Figure 18. Life cycle economic loss due to repairing the cracks are higher
in the strong-column and weak-beam structure than the weak-column andstrong beam strucutre, but life cycle economic loss due to repairing thespalling are higher in the weak-column and strong beam strucutre than thestrong-column and weak-beam structure.
Repairing cost of spalling depends on the maximun interstory drift
ratio through the life length. As shown in Figure 19, the maximum
interstory drift ratio, which come out at the 2nd floor, is larger in the theweak-column and strong beam strucutre than the strong-column and weakbeam structure. On the contrary, repairing cost of cracking depends not on
the maximun drift ratio but on the extent of cracking area. The strongcolumn and weak-beam structure shows the smaller maximum drift ratio at
the 2nd floor, but its drift ratio at the other floor is larger than that of the
weak-column and strong beam strucutre. This extent of cracking area affects
the repairing cost of cracking. Life cycle economic loss due to falsework islarger in the case of the exterior frame or the strong-column and weak-beam
structure because of the extent of damaged area.
Condition
Crack width < 0.2mm
Crack width < 1.0mm
Crack width ≥ 1.0mm
Spalling ratio < 0.05
Spalling ratio ≥ 0.05
at Interior Column
at Interior Beamat Exterior Column
at Exterior Beam

Table 2: Repairing Scenario
Repair method
Sealing
Epoxy injection
U-cut sealing / Cement grout
Patching resin mortar
Jacketing / Replacement
No falsework
Half floor hight
False- Damaged floor level
work
Damaged floor levelhight+ half floor hight

Unit price$9.1 /m$66.0 /m
$125.4 /m$270.0 /m2$542.3 /m2$20.0 /m2

Figure 18: Calculated Life Cycle Economic Loss Figure 19: Maximum IDR
A Study on Seismic Repair Cost of R/C Building Structures Using A Geometrical Damage Estimation Modelof R/C Members

321

October 2009, Incheon, Korea

5. CONCLUDING REMARKSLife cycle economic loss defined as the repairing cost of a building structure
through its life length was simulated using a new damage estimation model
which is partially based on cyclic load tests of one third scaled R/Cmembers. It is concluded that strong-column and weak-beam system will
suffer more life cycle economic loss than weak-column and strong-beamsystem because of the extent of cracking area and the construction cost offalsework.

REFERENCES
AIJ, 2004. Guidelines for Performance Evaluation of Earthquake ResistantReinforced Concrete Buildings (Draft). (in Japanese)
CEB-FIP, 1978. Model Code for Concrete Structures
Igarashi, S., 2009. Development of Analytical Model for Reparability
Evaluation of RC Columns Based on Damage (Part 1 – Part 3), Summaries
of Technical Papers of Annual Meeting of Architectural Institute of Japan,
Vol.C-2, 513-518. (in Japanese)
NIED, 2005. Japan Seismic Hazard Information Station (J-SHIS), http://
www.j-shis.bosai.go.jp/j-shis/
Takahashi, N. et al., 2005. Repair Cost Function in Seismic Reparability
Assessment for R/C Structures, Proc. of Japan Concrete Institute, Vol.27,
No.2, 1543-1548. (in Japanese)
Takahashi, N. et al., 2006. Life Cycle Input Ground Motion Intensities for
the Seismic Loss Estimation of the Building through its Lifetime, Proc. of
12th Japan Earthquake Engineering Symposium, 422-425. (in Japanese)
Takimoto, K. et al., 2004. Study on Evaluation of Damage of RC Beams
using Crack Data, Journal of the Japan Society of Civil Engineers,
No.760/V-63, 135-145. (in Japanese)
Takeda, T. et al., 1970. Reinforced concrete response to simulated earthquakes, Journal of Structural Division, ASCE, 96:ST12, 2557-2573

322

New Technologies for Urban Safety of Mega Cities in Asia

EXPERIMENTAL STUDY ON PP-BAND
MESH SEISMIC RETROFITTING
FOR LOW EARTHQUAKE RESISTANT
ARCH SHAPED ROOF MASONRY HOUSESNAVARATNARAJAH SATHIPARAN
Post Doctoral Fellow, The University of Tokyo, Japansakthi@risk-mg.iis.u-tokyo.ac.jp
PAOLA MAYORCA
Project Research Associate, ICUS, Institute of Industrial Science,
The University of Tokyo, Japanpaola@iis.u-tokyo.ac.jp
KIMIRO MEGURO
Director/ Professor, ICUS, Institute of Industrial Science,
The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp

ABSTRACT
Unreinforced masonry structure is one of the most popularly used
constructions. It is also unfortunately the most vulnerable to theearthquakes. It would collapse within a few seconds during earthquake
movement, and does become a major cause of human fatalities. Therefore,
retrofitting of low earthquake-resistant masonry structures is the key issue
for earthquake disaster mitigation to reduce the casualties significantly.
When we propose the retrofitting in developing countries, retrofitting
method should respond to the structural demand on strength anddeformability as well as to availability of material with low cost including
manufacturing and delivery, practicability of construction method anddurability in each region. Considering these issues, a technically feasible
and economically affordable PP-band (polypropylene bands, which iscommonly utilized for packing) retrofitting technique has been developed
and many different aspects have been studied by Meguro Laboratory,
Institute of Industrial Science, The University of Tokyo.
Unreinforced masonry structures with masonry arch shaped roofs are
generally characterized by weak, brittle materials, weak element
connections and excessive weight. The main points of weakness of the
traditional masonry arch roofs that contributed to poor seismic response
can be inability of the roof to act as a diaphragm and heavy weight of theroof. But ability of PP-band mesh kept the structure integral during theshaking will help to overcome this issues. Therefore, to evaluate thebeneficial effects of the PP-band mesh retrofitting method, shaking table
tests were carried out on arch shaped roof masonry structure with andwithout retrofitting.

323

October 2009, Incheon, Korea

From tests’ results, a scaled model with PP-band mesh retrofitting isable to withstand larger and more repeatable shaking than that without PPband retrofitting, which all verified to reconfirm high earthquake resistantperformance. Therefore proposed method can be one of the optimum
solutions for promoting safer building construction in developing countries
and can contribute earthquake disaster reduction in future.

1. INTRODUCTION
Unreinforced masonry structures with masonry arch roofs are generally
characterized by weak, brittle materials, weak element connections andexcessive weight. The main points of weakness of the traditional masonryarch roofs that contributed to poor seismic response can be summarized asfollows:
 Inability of the roof to act as a diaphragm: Masonry arch roofs areincapable of diaphragm action. This is due to their curved geometries, theload-carrying mechanisms and the weak and brittle materials. The loadcarrying mechanism of these types of roofs is primarily in compression.
The non-homogeneous masonry of the roofs is unable to carry tensile or
flexural loads. As a result, they are not capable of restraining the top of
their supporting walls during ground shaking, nor are they capable oftransferring excessive horizontal inertia forces. Furthermore, they induce
a pre-earthquake static horizontal force at the top of the walls as theytransfer their compressive load to the walls. In the shared load-bearing
walls, the thrust from the two adjoining arches cancel each other out.
However, in end arches this force causes an unbalanced outward thruston the wall.
 Heavy weight of the roof: Perhaps the most important seismic weaknessof the masonry arch is their excessive weight. The masonry arch roofs are,by nature heavy, as a minimum roof thickness is required to enable thesuccessful transfer of the gravity load in an arch action.

2. EXPERIMENTAL PROGRAM
2.1 Description of the specimens
For shaking table experiment, three models were built in the reduced
scale of 1:4 using the unburnt brick as masonry units and cement lime andsand (1:2.8:8.5) mixture as mortar with cement/water ratio of 0.33.
Attention was paid to make the models as true replica of adobe masonrybuildings in developing countries in terms of masonry strength even though
the construction materials used were those available in Japan.
Buildings dimensions were 933mmx933mmx720mm box shape with
380 mm height arch shape roof as shown in Figure 1. Wall thickness is324

New Technologies for Urban Safety of Mega Cities in Asia

50mm. The sizes of door and window in opposite walls were 243x485mm2
and 325x245mm2 respectively.

Figure 1: Model dimension (mm)Table 1 shows the shaking table testing programs. The specimens
were named according to the following convention: B-R-P-S in which;
B is
R is
P is

S is

Brick type used for construction of the model
A: unburned brick;
Roof type - AR: arch roof
Retrofitted condition
NR: non-retrofitted
RE: retrofitted;
Condition of tie bar
TB: with tie bar (10 mm bar with 160x160mm2 timber plate at end)
TX: without tie bar

Case No.
1
2
3

Table 1: Summary of shaking table test
Specimen Name
PP-band Retrofitting
A-AR-NR-TB
X
A-AR-RE-TXO
A-AR-RE-TB
O

Tie barO
XO

Experimental Study on PP-band Mesh Seismic Retrofitting for Low Earthquake Resistant Arch Shapes Roof
Masonry Houses

325

October 2009, Incheon, Korea

Totally two out three models were retrofitted with PP-band mesh after
construction. The cross-section of the band used was 6x0.24mm2 and themesh pitch was 40mm. The mechanical properties of masonry in terms ofcompressive, shear and bond strength were given in Table 2.
Table 2: Mechanical properties of masonry specimens (in MPa)
Diagonal
Compression
Shear
Bond
Specimenshear strength
strength
strength Strength
A-AR-NR-TB
0.042
4.36
0.00550.0050A-AR-RE-TX
0.052
4.44
0.00520.0055A-AR-RE-TB
0.048
4.28
0.00620.0046
2.2 Construction and retrofitting procedure
All specimens have two part; box shape house and arch roof. Box
shape house consisted of 18 rows of 44 bricks in each layer except openings
and arch roof consisted of 29 rows of 11½ bricks in each layer. Box shapehouse construction process takes place in two days, first 11 rows in first day
and remaining rows construct in following day. Arch roof construction
procedure take place after 7 days from initial construction of box shapehouse. Remaining two side walls constructed take place 7 days after archroof construction.
In case of retrofitted specimen initially boxed shaped was constructed
and retrofitted. Then arch framework place above box house model and PPband mesh cover that arch frame. Arch roof construction procedure takeplace after 7 days from initial construction of box shape house. After 4 daysof curing arch framework was removed. PP-band mesh come from inside
the arch roof and box house model were welded by ultrasonic welding
machine. Remaining two side walls constructed 7 days after arch roof
construction. And finally PP-band mesh come from outside the arch roof
and outside box house model were welded and retrofitted by wire
connectors. Construction and retrofitted procedure of house model was
shown in Figure 2.
2.3 Input motion
Simple easy-to-use sinusoidal motions of frequencies ranging from
2Hz to 35 Hz and amplitudes ranging from 0.05g to 1.4g were applied toobtain the dynamic response of both retrofitted and non-retrofitted structures.
This simple input motion was applied because of its adequacy for later use
in the numerical modeling. Figure 3 shows the typical shape of the appliedsinusoidal wave.
Loading was started with a sweep motion of amplitude 0.05g with all
frequencies of 2Hz to 35Hz for identifying the dynamic properties of themodels. The numbers in Table 2 indicate the run numbers. General trend ofloading was from high frequency to low frequency and from lower
amplitude to higher amplitude. Higher frequencies motions were skipped
towards the end of the runs.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Retrofitting Procedure

Figure 3: Typical Shape of Input Sinusoidal Motion
Experimental Study on PP-band Mesh Seismic Retrofitting for Low Earthquake Resistant Arch Shapes Roof
Masonry Houses327

October 2009, Incheon, Korea

Table 2: Loading Sequence
Frequency
Amplitude
2Hz 5Hz 10Hz 15Hz 20Hz 25Hz 30Hz 35Hz
1.4g
50
1.2g
54
49
1.0g
48
0.8g
53
47
43
40
37
34
31
28
0.6g
52
45
42
39
36
33
30
27
0.4g
51
44
41
38
35
32
29
26
0.2g
46
25
24
23
22
21
20
19
0.1g
18
17
16
15
14
13
12
11
0.05g
10
09
08
07
06
05
04
03
sweep
01,02

3. CRACK PATTERN AND ENERGY DISSIPATION MECHANISM
For specimen A-AR-NR-TB up to run 21, no major crack was observed inthis model. Major cracks were observed closer to openings from run 22.
After that, cracks widened with each successive run. At run 30, cracks
appear three corner of the window opening and propagate towards thecorner of the wall. Also crack observed left half circle of the east wall-archinteraction and this crack propagate full circle of east wall-arch interaction
with successive runs. At run 36, wall-arch interaction in both east and west
wall was totally cracked. Even it totally cracked, presence of tie bar, archroof prevented from splitting outward. Also large amount cracks wereobserved in roof part. Particularly, long horizontal crack at initial roof partof walls in direction shaking was observed. At run 39, top part of the east
wall (part, above the window opening) was totally separated from thespecimen and it was fallen from specimen. At run 41, top part of the west
wall (above the door opening) was totally separated from the specimen andit’s fallen from specimen. As a result arch part only supported by two walls,
which are in the direction of shaking and due to walls subjected to out-ofplane load; arch part was bursts outwards in shaking direction. This finally
led to the structure collapse at run 42.
For retrofitted specimen A-AR-RE-TX up to Run 21, no major crack was
observed in this model. Major cracks were observed closer to openings fromRun 22. After that, cracks widened with each successive run. At run 33,
wall-arch interaction in both east and west wall was totally cracked. Long
horizontal cracks were observed in top of the arch roof. Also large amountcracks were observed in roof part. Particularly, long horizontal crack at
initial roof part of walls in direction shaking was observed. At run 45,
although at the end of this run almost most of the mortar joints were cracked,
the specimen did not lose stability. Although PP-band mesh kept thestructure integral during the shaking, it allowed the sliding of the bricks
along these cracks to some extent. At the final stage of the test, run 54, with
50mm base displacement, 33 times more than the input displacement

328

New Technologies for Urban Safety of Mega Cities in Asia

applied in run 42 and 7 times more velocity, virtually all the brick joints
were cracked and the building had substantial permanent deformations.
However, building did not loose the overall integrity as well as stability andcollapse was prevented in such a high intensity of shaking. Anotherimportant point to mention that this retrofitted model has sustained 12 moreruns with higher input energy before this run.
In smaller input motions in case of retrofitted specimen A-AR-RE-TB,
amount of crack relatively fewer than that case of specimen A-AR-RE-TB.
But in higher input motion, in both models, there are not much difference
observed in dynamic performance. Like specimen A-AR-RE-TX, run 54
was the last run for specimen A-AR-RE-TB.
4. FAILURE BEHAVIOR AND PERFORMANCE EVALUATION
The performances of the models were assessed based on the damage level ofthe buildings at different levels of shaking. Performances were evaluated inreference to five levels of performances: light structural damage, moderate
structural damage, heavy structural damage, partially collapse and collapse.
Category
D0: No damage
D1: Light
structural damage

Table 3: Damage categories
Damage extension
No damage to structure
Hair line cracks in very few walls. The structure
resistance capacity has not been reduce noticeably.

D2: Moderate
structural damage

Small cracks in masonry walls, falling of plasterblock. The structure resistance capacity is partiallyreduced.

D3: Heavy
structural damage

Large and deep cracks in masonry walls. Somebricks are fall down. Failure in connection between
two walls.

D4: Partiallycollapse
D5: Collapse

Serious failure of walls. Partial structural failure ofroofs. The building is in dangerous condition
Total or near collapse

The Japan Meteorological Agency seismic intensity scale (JMA) is ameasure used in Japan to indicate the strength of earthquakes. The JMA
scale was colored according to the following convention:
Index

JMA ~4

JMA 5-JMA 5+JMA 6-JMA 6+JMA 7

4.1 Performance evaluation based on JMA scale
Table 4 shows the performances of non retrofitted model A-AR-NRTB with different JMA intensities. Partial collapse of the non-retrofitted
building was occurred at the 39th run at intensity JMA~4 and total collapse
at the 42nd run at intensity JMA~4. But it should be noted that the model
was already cracked in different loadings as discussed in previous section.

Experimental Study on PP-band Mesh Seismic Retrofitting for Low Earthquake Resistant Arch Shapes Roof
Masonry Houses329

October 2009, Incheon, Korea

Table 4: Performance of A-AR-NR-TB model
Acceleration
Frequency (Hz)
(g)
2
5
10
15
20
25
1.4
1.2
1.0
0.8
D4
D3
D2
0.6
D5
D4
D3
D2
0.4
D4
D3
D2
D2
0.2
D1
D1
D1
D1
D0
0.1
D1
D1
D1
D1
D1
D0
0.05
D0
D0
D0
D0
D0
D0

30

35

D2
D2
D2
D0
D0
D0

D2
D1
D1
D0
D0
D0

Table 5 shows the performances of non retrofitted model A-AR-RETX with different JMA intensities. The A-AR-RE-TX performed at heavy
structural damage at 42nd run at which A-AR-NR-TB was collapsed. Heavy
structural damage level of performance was maintained until 52nd run. Test
was stopped after the 54th run due to limitation of the shaking table capacity.
It should be noted again that this model survived 13 more shakings in which
many runs were with higher intensities than A-AR-NR-TB was collapsed
before reaching to the final stage at the 54th run.

Acceleration
(g)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.1
0.05

Table 5: Performance of A-AR-RE-TX model
Frequency (Hz)
2
5
10
15
20
25
D3
D3
D3
D4,D4 D3
D3
D3
D3
D2
D3
D3
D3
D3
D2
D2
D3
D3
D3
D3
D2
D2
D3
D2
D1
D1
D1
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0

30

35

D2
D2
D2
D0
D0
D0

D2
D2
D2
D0
D0
D0

Table 6 shows the performances of retrofitted model A-AR-RE-TB
with different JMA intensities. The A-AR-RE-TB performed at moderate
structural damage at 42nd run at which A-AR-NR-TB was collapsed. In thesame run specimen A-AR-RE-TX was performed at heavy structural
damage level. In the 47th run, another JMA 5+ intensity shaking, the A-ARRE-TB got the heavy structural damage level, which is crushing, extensive
cracking, and damage around openings. Test was stopped after the 54th run
due to limitation of the shaking table capacity. It should be noted again that
this model survived 13 more shakings in which many runs were with higher
intensities than A-AR-NR-TB was collapsed before reaching to the final
stage at the 54th run.

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New Technologies for Urban Safety of Mega Cities in Asia

Acceleration
(g)
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.1
0.05

Table 6: Performance of A-AR-RE-TB model
Frequency (Hz)
2
5
10
15
20
25
D3
D3
D3
D3,D3 D3
D2
D2
D2
D2
D3
D2
D2
D2
D2
D2
D3
D2
D2
D2
D2
D2
D2
D1
D1
D1
D1
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0
D0

30

35

D1
D1
D1
D0
D0
D0

D1
D1
D1
D0
D0
D0

4.2 Performance evaluation based on Arias intensity scale
The Arias intensity was initially defined (Arias, 1970) as

 t

(1)
a 2 (t )dt
2 g 0and was called scalar intensity. It is directly quantifiable through theacceleration record a(t), integrating it over the total duration of theearthquake. The arias intensity is claimed to be measure of the total seismicenergy absorbed by the ground.
Ia 

Figure 4 shows the performance level of each specimen against
dynamic motion. Figure 5 shows the specimen capacity against dynamic
motion for each specimen. From results, it’s clearly show that; retrofitted
model damage level performance at least 5 times better than that of nonretrofitted model.

Figure 4: Performance evaluation based on arias intensity
Experimental Study on PP-band Mesh Seismic Retrofitting for Low Earthquake Resistant Arch Shapes Roof
Masonry Houses

331October 2009, Incheon, Korea

Figure 5: Specimen capacity against shaking
5. CONCLUSION
This paper introduced the shaking table test program on arch shaped roof
masonry houses. Form test result showed that;For specimen A-AR-NR-TB, after run 36; due to presence of tie bar,even wall-arch interaction in both east and west wall was totally
cracked; arch roof prevented from splitting outward. It totally failed atrun 42.
AR-RE-TX & A-AR-RE-TB were withstands base displacements 50
times larger and velocities 10 times higher than the A-AR-NR-TB. It
should be noted again that these models survived 13 more shakings inwhich many runs were with higher intensities than A-AR-NR-TB was
collapsed before reaching to the final stage at the 54th run.

Considering overall performance of the both specimens, PP-band caneffectively increase the seismic capacity of masonry houses and therefore
reduce the number of casualties in the coming earthquakes.
REFERENCE
Mahmoud R. Maheria. Performance of Building Roofs in the 2003 Bam, Iran Earthquake,
Earthquake Spectra, Volume 21, No. S1, pages S411–S424, December 2005
T.Fujieda, P.Mayorca, N.Sathiparan and K.Meguro, Experimental Study on the
Behavior of PP-band Mesh Retrofitted Masonry Houses using Miniature Models,Bulletin of Earthquake Resistant Structure Research Centre, March 2008, No.41, 67-72
Pilot Studies for Knowledge Assistance for Verification and Promotion on a New
Seismic Retrofitting method for existing masonry Houses by Polypropylene Band
Mesh (The Islamic Republic of IRAN), Final Report, JBIC, ICUS, OYO
International Corporation, July 2007.

332

New Technologies for Urban Safety of Mega Cities in AsiaREPLACEABLE SLAB OF OPEN-TYPE
PIERS AS NEW COST-EFFECTIVETECHNOLOGY
Yuichiro KAWABATA, Mitsuyasu IWANAMI, Ema KATO
Structural Mechanics Division
Port and Airport Research Institute, Japan
kawabata-y@pari.go.jp, iwanami@pari.go.jp, katoh-e@pari.go.jp
Hiroshi YOKOTA
Research Group of Sustainable Infrastructure System
Hokkaido University, Japan
yokota@eng.hokudai.ac.jp
Masahiko FURUICHI
Director for Special Research
Port and Airport Research Institute, Japanfuruichi-m2dd@pari.go.jp

ABSTRACTThe authors proposed an idea of “replaceable” slab for open-typepiers as an appropriate maintenance solution of port structures without
interrupting the facility services. The replaceable slab is a precast RC
member, placed on RC beams with rubber shoes. It is recommended toutilize precast members in constructing superstructure of open-type piers inorder to reduce construction costs and construction period and to obtainhigher quality of RC members. When severe deterioration occurs in the slab
during the service period, the slab can be repaired by removing on land, or
replaced by a new intact slab so as to maximize net present value (NPV) of
the facility.
This paper presents the structural performance and the costeffectiveness of the replaceable slab of open-type piers. Joint details were
investigated to realize the replaceable slab of open-type piers throughloading tests on models of precast RC slab connected to beams by the
proposed joint. Based on the test results, the replaceable joint system was
proposed by comparing structural performance and fracture behavior of thereplaceable slab with those of the conventional RC slab. One trial
calculation revealed that the replaceable slab was cost-effective comparedto the conventional RC slab in case of development of large-scale container
terminal.

1. INTRODUCTION
Reinforced concrete (RC) members consisting of superstructure ofopen-type piers are exposed to very severe conditions, resulting in early
deterioration of concrete structures due to chloride attack. In such conditions,corrosion of reinforcing steel bars progresses rapidly, because protective333

October 2009, Incheon, Korea

coatings are inadequate around the bars, and structural performance of RC
members degrades as the cross-section of reinforcing bars reduces. For suchdeteriorated RC superstructures, appropriate maintenance should be
required from the viewpoints of durability and safety of the piers. In Japan,
a lot of piers need repair works only a few decades after completion of
construction because durability of RC in design had not been consideredappropriately. In repairing superstructure of the piers, it is necessary to set
up temporary scaffolds under the superstructure. Since working time isstrictly limited due to interference of tidal actions and waves, and working
conditions are considerably poor due to narrow clearance under thesuperstructure and high humidity, the repair works to deteriorated RC
superstructure of the piers are costly, causing an increase in life-cycle costsof the piers and beneficial loss due to restricting cargo handling operations.
The authors proposed an idea of “replaceable” slab for open-typepiers (see Fig. 1) as an appropriate maintenance solution of port structures
without interrupting the facility services. The replaceable slab is a precast
RC member, placed on RC beams with rubber shoes. It is effective to utilize
precast members in constructing superstructure of open-type piers in orderto reduce construction costs and construction period and to obtain higher
quality of RC members. Normally, after placing the precast slab on the
beams, the slab is rigidly connected to the beams by splicing projecting
rebars from RC members and casting concrete between them. Fig. 2 shows
one of the typical methods to connect concrete members in superstructure of
the piers. The structural behavior of the superstructure constructed by theconnection method such as Fig. 3 are similar to those of the conventional
superstructure in which beams and slabs are simultaneously constructed insitu.
On the other hand, the replaceable slab is connected temporarily by
the replaceable joint system to the beams so that the slab can be removed
easily during the service period. Hence, when severe deterioration isdetected in the slab at periodical inspections during services, the slab can be
repaired on land after removing, or replaced by a new intact slab. As a result,it enables us to omit repair works on temporary scaffolds under the slab,
resulting in reduction of maintenance costs of the piers without interruptingcargo handling operations.
In this study, joint details were investigated to realize the replaceableslab of open-type piers through loading tests on models of precast RC slab
connected to beams by the proposed replaceable joint. In the tests, a variety
of joint types and structural details were examined to determine appropriate
joints for the replaceable slab. Based on the test results, the replaceable joint
system was proposed by comparing structural performance and fracture
behavior of the replaceable slab with that of the conventional RC slab.
Structural design method of the replaceable slab was examined as well interms of supporting condition and span length.
In addition, cost-effectiveness of replaceable slab was investigatedusing Net Present Value (NPV) analysis. NPV of the replaceable slab wascompared with that of the conventional RC slab in a large-scale container
terminal as a case study.

334

New Technologies for Urban Safety of Mega Cities in Asia

Fig. 1 Replaceable slab

Fig. 2 Typical connection method(a) Type A(b) Type B
Fig. 3 Replaceable joint

2. REPLACEABLE JOINT FOR PRECAST RC SLAB
To realize the idea of replaceable slab of open-type piers, two types ofjoint structures were proposed as shown in Fig. 3. In Type A, a precast RC
slab is connected by using anchor bolts projecting from a supporting beam.
The slab is placed on rubber shoes on the beam with the anchor bolts
through holes in the edges of the slab, and then the nuts are tightened to fix
the slab. The nuts will be loosened, when removing the slab.
In Type B, the slab is connected by using a steel plate, which is fixedby an anchor bolt projecting from the beam. The edges of the two adjacentslabs are held down simultaneously. Compared with Type A, the number ofanchor bolts can be reduced, as shown in Fig. 3. However, since the heightof the beam is smaller, it is necessary to arrange more reinforcing bars or toenlarge the width of the beam in order to keep flexural rigidity of the beam.
There is no need to make holes in the slab for anchor bolts as in case ofType A.
Paying attention to the degree of connection between the slab and thebeam by these types of joints, the connection is not completely rigid.
Compared with simply supported members, they are connected more or lessby the anchor bolts or the steel plate. The degree of connection is dependent
on details of the joint, degree of tightening the nuts, type and size of rubber
shoes, position of the rubber shoes, and so on. It is essential to structuraldesign of the slab to investigate their effects on structural performance ofthe connection part.

Replaceable Slab of Open-Type Piers as New Cost-Effective Technology

335

October 2009, Incheon, Korea

For the purpose of establishing a design method of the replaceableslab for open-type piers, structural performance and fracture behavior of theslab connected to beams by the proposed joints should be made clear
through the experimental program.

3. STRUCTURAL PERFORMANCE OF REPLACEABLE SLAB
3.1 Experimental Outline
3.1.1 Experimental Set-up
In the experimental program, loading tests on models of precast RC
slab connected to beams by the joint of Type A or Type B were conducted
as shown in Fig. 4. Concrete blocks modeling beams were anchored by PCbars to a load bearing floor, and then a precast RC slab was placed on therubber shoes on the blocks. To connect the slab to the block, anchor bolts
and steel plates were used in case of Type A and Type B, respectively, as
illustrated in Fig. 4. The span of the slab was 3000mm, and the cross sectionof the slab was 1000mm by 300mm. The total length of the slab waschanged depending on the type of joint used.
The width and the height of rubber shoes were 150mm and 23mm,
respectively. The hardness of rubber material used was 61 degrees, which
was commonly used as shoes for bridges in Japan. The PC bars used asanchor bolts were of SBPR930/1080, and the diameter was 32mm. The steel
plate used for connection by Type B was of SS400, and the size was 750mm
by 500mm by 20mm. In the models used in this experiment, two anchor
blots were used for connection in each edge of the slab. The distance of two
anchor bolts was 500mm.

500

1000

3000

Nut

Load

Nut

Load

Steel plate

Rubber shoe

Concrete block

Precast RC slab
PC barPC barConcreteblock (Beam)Concreteblock (Beam)
Load bearing floor

Type A

Type B[ unit : mm ]Fig. 4 Experimental set-up

336

New Technologies for Urban Safety of Mega Cities in Asia

Table 1 Test cases
Model

Connection

Size of slab(m)

Strain of
PC bars(μ)

Overlapped
length
(m)

R

rigid

-

-

-

S

-

4.4x1.0x0.3

-

0.7

A1

Type A

4.0x1.0x0.3

200

0.5

A2

Type A

4.0x1.0x0.3

600

0.5

B1

Type B

3.4x1.0x0.3

200

0.2

B2

Type B

4.4x1.0x0.3

200

0.7

Remarks
Rigid connection(Conventional)
Simply supported

3.1.2 Test Cases
The test cases are indicated in Table 1. For comparison, models of
conventional slab which was constructed together with beams (Model R)
and of simply supported slab (Model S) were prepared. Two models were
tested for each type of joint. Model A1 and Model B1 were fundamental
cases. In Model A2, initially introduced strain of PC bars used as anchor
bolts was increased up to 600μ in order to examine how the degree oftightening the nuts affected the test results. In Model B2, the overlapped
length of slab over beam was enlarged up to 0.7m. Comparing Model B1and Model B2, influence of the position of rubber shoes on the test results
was evaluated.
3.1.3 Material Properties and Bar Arrangement
The water to cement ratio of concrete used in the slab was 0.57, andthe compressive strength and Young’s modulus of concrete cylinders at theloading tests was 33.1N/mm2 and 31.6kN/mm2, respectively. Two types ofdeformed bars were used as reinforcing bars of the slab. Yield strength andtensile strength of the bars were 371N/mm2 and 597N/mm2 for the bars of
13mm in diameter (D13), 404N/mm2 and 567N/mm2 for those of 16mm indiameter (D16), respectively.
In considering actual arrangement of reinforcing bars insuperstructure of open-type piers [3], bar arrangement of the precast RC
slab was determined as follows: in the lower layer, D13 and D16 wereplaced with the interval of 200mm. In the upper layer of reinforcing bars,
the edge part of the slab had the same bar arrangement as the lower layer inorder to resist negative moment occurring near the supporting points. In thecenter part of the slab, D16 was placed with the interval of 200mm in theupper layer. The cover thickness was 73.5mm for both layers of reinforcing
bars.
According to the results of calculation based on the beam-bending
theory, the first cracking load, the first yielding load and the ultimate load ofsimply supported slab (Model S) were 49kN, 155kN, and 184kN,
respectively.
3.1.4

Loading Test
The vertical loads were applied to the slab by using a hydraulic jack
mounted to a steel loading frame. The distance of two loading points was

Replaceable Slab of Open-Type Piers as New Cost-Effective Technology

337

October 2009, Incheon, Korea(a) Model R(b) Model S(c) Model A1(d) Model A2(e) Model B1(f) Model B2
Fig.5 Crack pattern
500mm. The loads were increased monotonically up to the ultimate failureof the slab.
During loading, applied loads, deflections of the slab, strains ofreinforcing bars and concrete, strains of PC bars, and displacements andstrains of steel plates were measured by a data logger.
3.2 Results and Discussions
3.2.1 Crack Pattern and Fracture Process
Fig. 5 shows crack patterns observed in a side surface of slabs after
the loading tests. As shown in Fig. 5, Model R failed in shear after flexural
cracks occurred on the top surface near the connection part of the slab andthe beam due to negative moment. It was because bending capacity of theslab was high since the shear span was short due to rigid connection of theslab and the beam. On the other hand, Model S showed typical flexural
failure, in which compressive fiber of concrete was crushed after yielding oftensile reinforcing bars.
In the both slabs connected by Type A joint, typical flexural failure
was observed. The crack patterns were similar to that of Model S. From this,in case of slabs connected by Type A joint, the slab seemed to behave like asimply supported member. Besides, the degree of tightening the nuts, that is,strain of PC bars had little influence on crack pattern and fracture process ofthe slab within the limit of this experiment.
As for the slab connected by Type B joint, when the overlapped
length was 0.2m (Model B1), the slab failed in bending, and the crack
pattern was similar to that of the simply supported case (Model S) and theslabs with Type A joint (Model A1 and Model A2). On the other hand,338

New Technologies for Urban Safety of Mega Cities in Asia

600

600
500

500

Model R

400
Load (kN)

400
Load (kN)

Model S

300

300

200

200

100

100

0

0
0

10

20

30

40

50

60

70

0

80

10

600

40

50

60

70

80

600

500

Model A2

500

Model A1

400

400
Load (kN)

Load (kN)30

Displacement (mm)Displacement (mm)

300

300

200

200

100

100

0

0
0

10

20

30

40

50

60

70

0

80

10

20

30

40

50

60

70

80

Displacement (mm)Displacement (mm)
600

600

500

Model B2500

Model B1400
Load (kN)

400
Load (kN)

20

300

300

200

200

100

100
0

0
0

10

20

30

40

50

60

70

80

Displacement (mm)

0

10

20

30

40

50

60

70

80

Displacement (mm)Fig. 6 Load-displacement curvewhen the overlapped length was 0.7m (Model B2), flexural cracks occurred
near the supporting points on the top surface as well as the bottom surface
near the midspan. It was because negative moment was induced near the
supporting points since the distance between the supporting points and the
PC bars fixing the steel plate was long.
3.2.2 Load-Displacement Curve
Fig. 6 shows load-displacement curves obtained from the loading tests.

Replaceable Slab of Open-Type Piers as New Cost-Effective Technology339

October 2009, Incheon, Korea

Table 2 Load bearing capacity of slab
Cracking load

Yielding load

(kN)

(kN)

R

119

394

600

S

40

161

220

A1

40

151

209

A2

40

219

454

B1

40

162

226

B2

42

143

210

Cal

49

155

184

Case

Maximum load(kN)

In the figure, the displacement is the measured deflection at the midspan of
the slab subtracting the average vertical displacements at the supporting
points.
Table 2 summarizes load bearing capacities of the slabs obtained fromthe loading tests together with the calculated ones of simply supported slab,
which was explained in 3.1.3.
In Model R where the slab failed in shear, since the shear span was
short due to rigid connection, flexural rigidity and load bearing capacity ofthe slab was considerably large compared with other test cases. The
maximum load was three times larger than that of the simply supported case(Model S).
The load-displacement curves of Model A1 and Model A2 weresimilar to that of the simply supported slab (Model S). Therefore, load
bearing capacities of these slabs were almost the same as that of Model S,
regardless of strain of PC bars (the degree of tightening the nuts). It meansthat structural performance of slabs connected to beams by Type A joint canbe evaluated by assuming to be a simply supported beam whose span length
is the distance between the two rubber shoes.
On the other hand, in case of slabs connected by Type B joint, when
the overlapped length was 0.2m (Model B1), the load-displacement curve
was similar to that of the simply supported case (Model S), and the load
bearing capacity was almost the same as that of Model S, similarly to theslabs connected by Type A joint. However, when the overlapped length was
0.7m (Model B2), the load-displacement curve was quite different from thatof Model B1. Also, the maximum load was much larger than that of Model
B1 although there were little difference in cracking load and yielding load
between Model B1 and Model B2. The reason for this difference can be
explained as follows: Before yielding of reinforcing bars, deformation of theslab was so small that negative moment was not induced near the supporting
points. Consequently, structural behavior of the slab were similar to those of
the simply supported case so that cracking load and yielding load were
almost the same as experimental and calculated ones of the simply
supported case. However, after yielding of reinforcing bars, deformation of
the slab became so large that fixing by steel plates started to get remarkable,causing negative moment near the supporting points. As a result, theapparent shear span became short like Model R, and therefore flexural340

New Technologies for Urban Safety of Mega Cities in Asia

rigidity and load bearing capacity increased. The maximum load of Model
B2 was double of that of Model B1 where the overlapped length was shorter.
It was found that the slab connected to beams by Type B joint withlarger overlapped length had greater load bearing capacity. However,
flexural cracks occurred on the top surface due to negative moment, causing
less durability of concrete members. Also, structural design of such slabs
was more difficult to establish than that of simply supported members. It
was considered that the overlapped length of slab over beam in case of TypeB joint should be as short as possible, such as 0.2m.

4. COST-EFFECTIVENESS OF REPLACEABLE SLAB OF OPENTYPE PIER
4.1 Target structure
NPVs of a 15meter-deep berth at Island City Container Terminal, Portof Hakata in Fukuoka Prefecture, Japan, were calculated for several
scenarios as a case study of a large-scale container terminal. The berth wasconstructed with jacket-type piers, of which total area was 5,250m2.
Expected container throughput capacity of the berth was 230 thousand
TEU/year.
4. 2 NPV analysis
In case of port facility, large-scale repair works inevitably interrupt
cargo handling operations resulting in a considerable decrease of annual
benefit of the facility. When assessing maintenance scenarios of the port
facility, its social benefits are to be taken into account as well as life-cycle
cost (LCC). Therefore, Net Present Value (NPV) was adopted as one of thesolution of cost-benefit analysis in this study.
The berth was assumed as open-type piers of which area andcontainer throughput capacity are the same as Island City Container
Terminal for simplified calculation. Social discount rate was assumed 4.0%.
LCC and beneficial loss caused by large-scale repair works for thesuperstructure were calculated according to the several maintenancescenarios (Table 3). Construction and maintenance costs were determinedaccording to the previous research (Kodama et al., 2001).
Table 3 Maintenance scenario
Scenario

Type of slab

Slab

Beneficial loss

surface coating at
initial and every 15 yrs.

C-P1
C-C1

Beam

Conventional
slab

C-C2
Replaceable
slab

R-C1

Cross-sectional repair
at 30 yrs.
Cross-sectional
Renewalrepair at 30 yrs.
at 30 yrs.
Cross-sectional
Replacerepair at 30 yrs.
at 30 yrs.

None
1/3 of cargo handlingfor 2 yrs.
1/2 of cargo handlingfor 2 yrs.
None

Table 4 Results of NPV analysis (unit: billion yen)
Scenario

Type of slab

LCC

Replaceable Slab of Open-Type Piers as New Cost-Effective Technology

TB

NPV

341

October 2009, Incheon, Korea
C-P1
C-C1

Conventional slab

C-C2
R-C1

Replaceable slab

32.1

106.1

74.0

31.3

105.0

73.7

32.8

104.5

71.6

31.2

106.1

74.9

Expected total benefit was 106.1 billion yen (Ministry of Land,
Infrastructure and Transport, 2006). Therefore, TBs were calculated withsubtraction of beneficial losses from expected total benefits. NPVs were
calculated with subtraction of LCCs from TBs.
4.3 LCM scenarios
Maintenance scenarios were assumed in service of 50 years (Table 3).
The basic strategy of C-P1 was based on preventive maintenance while thatof other cases was based on corrective maintenance. In R-C1 of which slab
was replaceable, however, the facility could be maintained without
restricting cargo handling operations. The beneficial losses of C-C1 and CC2 were determined empirically.
4. 4 Results and Discussion
Comparison of replaceable slab with conventional slab due to theresults of NPV analysis revealed that R-C1 was the most cost-effective
maintenance scenario. Replaceable slab could reduce LCC without
restricting cargo handling operations, even if its strategy was based oncorrective maintenance. Therefore, “replaceable” slab would be evaluated asa cost-effective technology because it enables the facility well maintainedwith optimum NPV of the project among the options.

5. CONCLUSIONS
From the experimental results of the loading tests on models of thereplaceable slab, it was concluded that the proposed replaceable joints, TypeA and Type B, may be used as the joint system for the replaceable slab ofopen-type piers. The overlapped length of slab over beam in Type B joint
should be determined appropriately since its influence on structural behaviorof slabs was not negligible.
NPV analysis revealed that replaceable slab was a cost-effective
technology because it enables the facility well maintained with optimum
NPV of the project.
REFERENCES
Kodama, S., Tanabe, T., Yokota, H., Hamada, H., Iwanami, M. and Hibi, T..
2001, Development of maintenance management system for existing openpiled piers, Technical note of the PHRI (in Japanese)
MinistryofLand,
InfrastructureandTransport,2006,
http://www.mlit.go.jp/tec/hyouka/public/jghks/karute/img/05111189001/05
111189001_2.pdf (in Japanese)342

New Technologies for Urban Safety of Mega Cities in Asia

DESIGN OF CRACK SELF-HEALING ON
CONCRETE STRUCTURES
TAE-HO AHN
Institute of Industrial Science, The University of Tokyo, Japan
than@iis.u-tokyo.ac.jp
TOSHIHARU KISHI
Institute of Industrial Science, The University of Tokyo, Japankishi@iis.u-tokyo.ac.jp

ABSTRACTThis study aims to develop and apply self-healing concrete as a new
method for crack control and enhanced service life in concrete structure.
This concept is one of the maintenance-free methods which, apart fromsaving direct costs for maintenance and repair, reduces the indirect costs –a saving generally welcomed by contractors. In this research, the selfhealing phenomenon of autogenous healing concrete using geo-materials
for practical industrial application was investigated. Moreover, a selfhealing concrete was fabricated by ready-mixed car in a ready-mixed
concrete factory, then used for the construction of artificial water-retaining
structures and actual tunnel structures.

1. INTRODUCTION
The serviceability limit of concrete structures is primarily governed by theextent of damage. Cracks, one of various types of damage, play animportant role in the serviceability limit. However, if it were possible toknow the reason for differing behavior of concrete structures exposed tolargely similar conditions, we might have the key for designing highdurability structures with low or negligible maintenance and repair costs.
Furthermore, the serviceability limit of concrete structures by cracking
might be overcome by crack control methodologies; the enhanced service
life of concrete structures would reduce the demand for crack maintenanceand repair. In particular, the utilization of self-healing technologies has highpotential as a new repair method for cracked concrete under the waterleakage of underground civil infrastructure such as tunnels, as shown in
Figure 1.
Recently, K. Van Breugel reported that the market survey for self-healing
cement-based materials as follows (K. V. Breugel , 2007). First, in case of
the USA, the cost for reconstruction of bridges has been estimated between$20 and $200 billion. The average annual maintenance cost for bridges inthat country is estimated at $5.2 billion. Comprehensive life cycle analyses343

October 2009, Incheon, Korea

indicate that indirect costs due to traffic jams and associated loss of
productivity are more than 10 times the direct cost of maintenance andrepair. For the United Kingdom, repair and maintenance accounts for almost
45% of the UK’s activity in the construction and building industry. In caseof Netherlands, one third of the annual budget for large civil engineering
works is spent on inspection, monitoring, maintenance, upgrade, and repair.
In case of Japan, East Japan Railway Company reported that maintenanceand repair cost of railway bridges and tunnels is estimated at $10 billion(T.H. Ahn and T. Kishi, 2007).

Figure 1: Application concept of self-healing concrete for the water leakage
of underground civil infrastructures as tunnels
The performance of structures with elapse of time is often reported withgraphs like that shown in Figure 2. In general, for high durability andnormal designs, increasing the volume of cracks in a structure increases therepair costs as shown Figure 2(b). However, when considering the selfhealing design, if a crack occurs, it will be healed autogenously after minor
damage, as shown Figure 2 (c) and (d). This concept is one of themaintenance-free methods which, apart from saving direct costs formaintenance and repair, reduces the indirect costs – a saving generally
welcomed by contractors. Furthermore, general construction philosophy has
begun to change from [Design and Construction concept: constructor
responsibilities for maintenance and repair of structures are limited] to[Design, Construction and Maintenance concept: constructor has

344

New Technologies for Urban Safety of Mega Cities in Asia

responsibilities including the maintenance, monitoring and repair for life
cycle of structures] as shown Figure 2. This trend shows that it is necessary
for both the industrial and research fields to develop concrete including selfhealing crack concepts in the near future.
The aim of this study is to develop autogenous healing concrete using
various mineral admixtures for practical industrial application. Especially, it
was investigated based on consideration with self-healing performance ofmaterials and cost effectiveness as shown Figure 2(d), in order to apply selfhealing concrete as a new method for crack control and enhanced service
life in concrete structures.
This study focused on two primary issues: (1) experimental and analyticaldesign of cementitious materials with self-healing capabilities, (2)development of a self-healing concrete using new cementitious materials at
normal water/binder ratio [over W/B=0.45] (T.H. Ahn and T. Kishi, 2008).
High durability design
Performance

Man made repair

1st repair

Cost

2nd repair

Required strength
Time

Time

(b)

(a)

Performance

Self healing(Self-repair after minor damage)

Cost

Cost Effective Method [Target]
Maintenance free method
Required strength• Materials Science• Chemical Science• Civil Engineering Tech.
Time

Time

(c)

(d)

Figure 2: (a), (b): Performance (a) and costs (b) over time for normal
structures (black line) and high durability design structures (red line). (c),(d): Performance (c) and cost (d) over time of the structure made with selfhealing concrete. (K. V. Breugel , 2007)

2. TEST PROGRAMS
2.1 Materials(1) Cement
Type I Japan Portland cement was used in all cementitious composite
and concrete mixtures.
(2) Mineral admixtures & Chemical agents
In order to compare the self-healing capability of cementitious
composite with various compositions, mineral admixtures such as expansive

Design of Crack Self-Healing on Concrete Structures

345

October 2009, Incheon, Korea

agent, geo-materials and chemical agents were used. These materials wereprepared based on self-healing performance as reported in the previous
researches (T.H. Ahn, 2008), (T.H. Ahn and T. Kishi, 2008). The expansive
agent, two geo-materials (A, B) and chemical agent used were commercial
products produced in Japan. Geo-material A was used for this investigation;
It has an SiO2 content of 71.3% and an Al2O3 content of 15.4%. It shows the
XRD pattern of geo-material, which reveals that it is mainly SiO2 andsodium aluminum silicate hydroxide [Na0.6Al4.70Si7.32O20(OH)4]. It also
contains montmorillonite, feldspar, and quartz, and its swelling is mainly
caused by the swelling of montmorillonite, which is a swelling clay mineral.
This type of geo-material swells 15-18 times its dry size when wetted bywater. Polycarboxylate-based superplasticizer was also used in order tofabricate specimens.
2.2 Specimens
Table 1 shows the mix proportions of cementitious composite
materials in this research. All cementitious composite pastes in this researchwere made at a constant water/cement ratio of 0.45. 200grams of cement
were used to make the cementitious paste. All the prepared cementitious
composite pastes were mixed manually for 5 minutes at ambient
temperature. The slump test was then conducted on a small volume of paste
using the mini-slump cone. The dosage of each superplasticizer was set in
the range of 0.8 – 2.50% in order to obtain the initial target flow. Paste flow
was measured at 30 minute intervals up to 90 minutes from mixing.
Table 1 Mix-proportions of cementitious composite materials based on the
self-healing design
SampleOPC
Expansive agent Geo-Materials
Chemical(A ,B type)additives
I
90%
O
O
II
90%
O
O
O
2.3 Estimation method of cementitious composites for crack healing
Cementitious composite pastes cylinders 5Ф x 10 cm in size wereprepared following the mini-slump test. They were cured for 120 days andthen artificially cracked in order to clarify the self-healing process. Crackwidth was controlled between 0.1 and 0.3 mm in consideration of the
maximum tolerable crack widths according to construction codes. After
cracking, the specimens were again water cured for 200 days.
2.4 Verification of self-healing capability on fabricated self-healing concrete
All cementitious composite materials with self-healing capability[called pre-mixed products] in this research were manufactured in thelaboratory. Table 2 and Table 3 show the mixing proportions of concretes;

346

New Technologies for Urban Safety of Mega Cities in Asia

Table 2 Mixing proportion of concrete
Binder (B)OPC (93%)3(kg/m )
Pre-mixed Products (7%)
Water/Binder (kg/m3)
W (W/B= 47.3%)
3
Sand (kg/m )S
3Gravel (kg/m )GSuperplasticizer
SP (1.15~1.35%)(% B by weight)

344.1
25.9
175
809
920
4.26~4.99

a W/B ratio of 47.3% and a S/A ratio of 46.6% were applied to all concretes.
Slump flow of concrete was measured at the initial point and after 30 and 60
minutes. Self-healing concrete 10Ф x 20 cm cylinders were prepared after
conducting the concrete slump test. They were cured for 1 month and thenartificially cracked in order to clarify the self-healing process. Crack width
was controlled between 0.1 mm and 0.3 mm according to the maximum
allowable crack widths dictated by construction code. The specimens werethen water cured for another 1 month after cracking.
Table 3 Mix-proportions of Binder
BinderOPC
Mineral admixtures
Plain Concrete
100%
0%Expansive Concrete90%
10%
Self-healing Concrete
93%
7%
Sample3. RESULTS AND DISCUSSION
3.1 Self-healing capability of cementitious composite materials(1) Effects of geo-materials on the self-healing
In order to develop cementitious composite materials with self-healing
capability compared to normal cement without self-healing capability at thenormal W/C ratio, sample I [OPC + Expansive agent + Geo-materials] wasinvestigated considering expansion and swelling terms.
Figure 3 shows the healing process of the cracked three-component
system under water supply. In this case, the crack with an initial width of
0.2 mm was almost healed after 28 days. Rehydration products between
cracks were clearly observed after 14 days, and the cracks self-healed
perfectly even though there were small cracks between the rehydration
products after 200 days, as shown in Figure 3 (f). Figure 4 shows the entire
self-healed shape of the cracked specimen by top, side, bottom and crosssection. It was composed of different phases between the original and selfhealing zone. Therefore, microscopy and SEM with EDS-detector werecarried out to investigate the morphology, shape, and size of re-hydration
products and to clarify re-crystallization.

Design of Crack Self-Healing on Concrete Structures

347

October 2009, Incheon, Korea

Figure 3: Process of Self-healing on the sample I pastes at normal
water/binder ratio of 0.45 (the three-component system)

Figure 4: Self-healed shape of cracked pastes according to regions such as
top, side, bottom and cross-section [in case of Sample I]

348

New Technologies for Urban Safety of Mega Cities in Asia

Figure 5 shows the re-hydration products on the surface of thespecimen between the original and self-healing zones in case of sample I.
Figure 5 (b) shows the X-ray map and spectra taken from rehydration
products. It was found that the re-hydration products were mainly composedof high alumina silicate materials as shown in the X-ray mapping results.
The self-healing zone was composed of modified gehelite phases (CASH)
with high alumina ions compared to original zone. This self-healing
phenomenon seems to be related to the crystallization by aluminosilicate
with calcium ion. This seems effective for sealing against water leakages.
From these results, it was concluded that application of geo-materials aredesirable for the application of self-healing concrete. However, self-healing
velocity for rapid water proof effect of water leakage needs to be improvedin order to apply for underground civil infrastructures. Therefore, sample II
has been tested in order to improve this. These results are reported anddiscussed in the following section.

Figure 5: Self-healing phenomenon of crack by crystallization ofaluminosilicate phases on the cementitious pastes incorporating expansive
agent and Geo-materials [Surface Analysis of specimen](2) Effects of chemical additives on the self-healing (Upgrade design)
The objective of upgrade design was to consider the chemical stability
as well as the improvement of self-healing velocity for the cementitious
composite materials. Figure 6 shows the process of self-healing of sample II
under water supply. In this case, the crack was healed after re-curing for 3days, as shown in Figure 6 (b). It was found that this design had greaterchemical stability compared to other results
Chemical additives significantly affected the formation of rehydration products with high chemical stability as compared to the previous
design. Furthermore, it didn’t show loss of re-crystallization products
compare to previous results after re-curing 3 days as shown in Figure 6 (c).
These rehydration products were mainly composed of fibrous phases fromchemical additives and calcite as shown in Figure 7. This indicates that these

Design of Crack Self-Healing on Concrete Structures349

October 2009, Incheon, Korea

fibrous phases, which were formed from chemical additives, play an importantrole in crack bridging between cracks. From these results, it was concluded thatvarious composite upgrade designs are desirable for the application of selfhealing concrete. Premix cementitious composite materials based on these results
were prepared for concrete mixing in order to give self-healing capability. These
results are reported and discussed simply in the following section.

Figure 6: Self-healing process of sample II [Upgrade design, Water/Binder
ratio of 0.45]

Figure 7: X-ray mapping results of fabricated fibrous phases and C-A-S-H
phases [Sample II, Water/Binder ratio of 0.45]

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New Technologies for Urban Safety of Mega Cities in Asia

3.2 Physical properties of self-healing concrete
Cement-based materials like concrete and mortar are quasi-brittle
materials. These materials show a softening behavior when tested in uniaxial tension. In order to quantify the early age behavior of self-healing
concrete as compared to those of conventional and expansive concrete, atemperature-stress testing machine (TSTM) test was conducted. Three typesof concrete – plain concrete, expansive concrete (EC) and self-healing
concrete (SHC)–were prepared for TSTM test and their experimental results
are presented in Figure 8. Under the same semi-adiabatic temperature
condition, the temperature evolution of the expansive concrete is slightly
higher than normal concrete, and that of self-healing concrete is slightly
lower than normal concrete. The first phenomenon was due to thereplacement of cement by expansive agent, which has a higher hydration
activity, thus the hydration heat on the first day elevated slightly. The
second phenomenon was caused by the cement amount, which is 10% lessin self healing concrete.
It is well known that expansive concrete can induce extra expansion tocompensate for shrinkage. The test results showed this tendency. After 20hours, the compressive stress of the expansive concrete was 0.8MPa higher
than that of normal concrete, whose was 1 MPa. After temperature of
specimens returned to room temperature, the tensile stress of expansive
concrete was slightly lower than that of normal concrete. This is because theextra expansion of expansive agent becomes stagnant after one day due tothe lack of water and the developing stiffness of surrounding hydrated
matrix. The restrained stress evolution of self healing concrete is between
these two concrete, the maximum compressive stress was 1.4MPa, and thefinal tensile stress was 1.6MPa. Even though the premix added in the selfhealing concrete was composed of many composites, its restraint stressdevelopment is similar to that of the expansive concrete. When comparing
the Young’s modulus, it can be seen that there is not large difference among
these types of binders. Based on the above, it could be concluded that thecracking sensitivity of self-healing concrete is similar to expansive concreteand has a better cracking resistance than normal concrete. Furthermore, incase of compressive strength, it can be seen that SHC exhibits similar
compressive strength to Plain as shown in Figure 9. This means that selfhealing concrete also passed the minimum field requirement forcompressive strength (red line).
For estimating the durability of concrete structures, it is necessary tounderstand the permeation of water into concrete. Water permeability ofself-healing concrete is one of several important concrete properties for theprevention of water leakage from water-retaining or underground structures.
In order to measure the permeability of concrete, this research adopted an
output method which enables the measurement of the permeation directly byobserving the reliability and starting point of hydraulic divergence of
permeation in concrete(T.H. Ahn, 2008). Table 4 shows the water
permeability test results of self-healing concrete. Generally, the function ofwater permeability coefficient is as follows.

Design of Crack Self-Healing on Concrete Structures351

October 2009, Incheon, Korea

Plain
ExpansiveSHCoTemperature( C)

50

40

30

20

Stress(MPa)

2
1
0
-1
-2
-3

Modulus(GPa)

25
20
15
10
5
0
0

20

40

60

80

100

120

140

Time(h)Figure 8: TSTM results of various concrete

Figure 9: Compressive strength of self-healing concrete
k=q/i
(1)
Where
K : water permeability coefficient (m/sec),
q: water flow /unit time and volume (m3/m2/sec),
i : hydraulic gradient
Table 4 Comparison water permeability between conventional concrete andself-healing concrete
SampleTime (s)V (cm/s)
K (m/s)Plain
60
0.000294
5.35E-05
SHC
1800
8.69E-06
1.65E-06

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New Technologies for Urban Safety of Mega Cities in Asia

Water pressure was 2.0 MPa (=2 x 106 N/m2) in this research. Eachspecimen was cured for 28 days, and then immersed in water again for 2days in order to estimate the water permeability. The result showed thatwater permeability coefficient of self-healing concrete was significantly
lower than that of conventional concrete. This indicates that self-healing
cementitious composite could be used as a mineral admixture for the sealingof water leakage.
3.3 Self-healing capability of self-healing concrete
In case of self-healing concrete, the crack was significantly self-healed
up to 28 days re-curing. Figure 10 shows the healing process of cracked
self-healing concretes made at the same mixing condition as theconventional concrete. A 0.15 millimeter crack was self-healed after 3 days
re-curing, as shown Figure 10 (b). After re-curing for 7 days, the crack
width decreased from 0.22 millimeters to 0.16 millimeters. Furthermore, it
was almost completely self-healed at 33 days as shown in Figure 10 (d).

Figure 10: Process of self-healing on self-healing concrete at water/binder
ratio of 0.47
This recovery appeared to include self-healing phenomenon such as
the swelling effect, expansion effect and re-crystallization as mentioned
above. However, in general, it should be considered that cracked aggregate
didn’t heal by itself. Self-healing at the initial stage occurred in the
cementitious paste area between cracks as shown in Figure 11, resulting in
the healing between the cementitious paste and surface of aggregate.
However, this type of crack did not perfectly self-heal at the same time asshown in Figure 11. Some re-crystallization structure from the cementitious
paste was deposited on the aggregate surface or in the crack between
aggregates as shown in Figure 12. Therefore, this indicates that cracks ofthese types will take more time for self-healing.

Design of Crack Self-Healing on Concrete Structures353

October 2009, Incheon, Korea

Figure 11: Process of self-healing on self-healing concrete at water/binder
ratio of 0.47

Figure 12: Self-healing images on crack between aggregate zone andaggregate zone of self-healing concrete

4. CONCLUSIONSIn this study, the self-healing properties of concrete using various mineraladmixtures were investigated.
(1) Self-healing capability was significantly affected by aluminosilicate
materials and various modified calcium composite materials.
(2) The essential properties such as expansion, swelling and recrystallization for self-healing design were analyzed and discussed.

REFERENCES
K. V. Breugel, 2007. Is there a market for self-healing cement-based materials?,
Proceedings of the 1st International Conference on Self-Healing Materials, 18-20 April
T.H. Ahn, T. Kishi, 2007. 1st International conference on self-healing materials, Con
ference Review, Magazine of Korea Concrete Institute (KCI), Vol 14(4), pp.82-85.
T.H. Ahn, 2008. Development of self-healing concrete incorporating geo-materials :A study on its mechanism and behavior in cracked concrete, Ph.D. dissertation,
Department of Civil Engineering, University of Tokyo, Japan.
T.H. Ahn, T. Kishi, 2008. The effect of geo-materials on the autogenous healing
behavior of cracked concrete, Proceeding of 2nd ICCRRR2008, Cape town, South
Africa.

354

New Technologies for Urban Safety of Mega Cities in Asia

EXPERIMENTAL EXAMINATION ON
THE REPAIR EFFECT OF EMERGENCY
RAPID RETROFITTING METHOD TST-FiSH
MASAMITSU SUZUKI
Department of Architecture and Civil Engineering,
Shibaura Institute of Technology, Japanm-suzuki@iis.u-tokyo.ac.jp
RYOTA KASAKURA
Tokyu Construction, Japan
kasakura.ryouta@tokyu-cnst.co.jp
MASANORI ITO
Tokyu Construction, Japanitou.AI9184@tokyu-cnst.co.jp
YOSHITAKA KATO
ICUS, IIS, University of Tokyo, Japankatoyosh@iis.u-tokyo.ac.jp

ABSTRACT
After disasters such as earthquakes, it is necessary to quickly repair
damage in order to ensure safety and speed recovery efforts. However,conventional methods require large-scale operations and the repair effectmay be delayed. Therefore, the authors proposed an emergency rapid
retrofitting method utilizing fiber sheets containing hydraulic resin (TSTFiSH) for the repair of reinforced concretes structure. The goals of this new
method are to provide higher safety, speed, and ease of applicationcompared to conventional methods. The basic properties were evaluated byadhesion test, the repair effect was investigated by beam specimen, and thestructural performance was confirmed by column specimen. As a result, incomparison with conventional fiber sheet wrapping method, it was
confirmed that TST-FiSH can provide the same repair effect and with only
one-tenth of the application time. This paper reports these experimentresults and the applicability of emergency rapid retrofitting method TSTFiSH.

1. INTRODUCTION
In Japan, the importance of seismic reinforcement in concrete
structures was realized after the Hanshin/Awaji great earthquake disaster of
1995. Seismic reinforcement improves ductility primarily by avoiding thebrittle “shear fracture" which occurs in column members. Maintransportation and emergency transportation roads in the Tokyo
metropolitan area are mostly reinforced by this method; however, there arestill many structures which may suffer serious damage due to the scale ofthe earthquake. In addition, new structures cannot avoid damage, as they are355

October 2009, Incheon, Korea

designed to permit some damage during a large-scale earthquake. When
structures are damaged by natural disasters, they require emergency
retrofitting to ensure safety and functionality. Conventional methods,
however, cannot adequately cope with subsequent aftershocks, and largescale repair works are time consuming. From a concept inspired by medical
plaster casts, a new repair method utilizing fiber sheets containing hydraulicresin (TST-FiSH) was developed to address this problem. This method canrepair reinforced-concrete structures through the hardening effect ofhydraulic resin when sprayed with water, and can provide higher safety,
speed, and ease of application compared to conventional methods (Figure 1).

Figure 1: Summary of conceptual method
When the repair effect of sheets using polyurethane resin and glass
fiber sheets was examined experimentally it was found that the stresscapacity recovered to the same level or higher than before damage,indicating that practical application is possible (Suzuki et al., 2008).
However, several questions remain: first, how much damage can be repairedby the emergency rapid retrofitting method, and second, what is the behavior ofdifferent fiber sheets, such as carbon, aramid, or vinylon. This research examined
the potential application of the hydraulic resin using various types of fiber
sheets, and the repair effect was confirmed by experimental testing of
damaged and repaired beam and column members.

2. EXPERIMENTAL PROCEDURE
2.1 Materials
2.1.1 Hydraulic polyurethane resin
The hydraulic polyurethane resin used in this study is a single liquidhardening resin which reacts and begins hardening after contact with waterand in the presence of carbon dioxide. The resin was diluted with glycol
ether solvent because the pure resin was difficult to handle due to highviscosity. Resin density 66% was chosen based on experimental results.
2.1.2 Fiber Sheet
The physical properties of the fiber sheets used in the experiments areshown in Table 1. The carbon fiber sheets are 2-directional and highstrength; aramid fiber sheets are 1-directional; and vinylon fiber sheets are
2-directional. The physical properties in Table 1 are published values.

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New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Physical properties of fiber sheets
Fiber sheet
CarbonAramidVinylonWeight(g/m2)
300
280
285

Tensile strength(N/mm2)
3400
2060
2000

Young modulus(N/mm2)2.45×105
1.18×105
4.30×10４

Fracture strain
(%)
1.5
1.8
4.8

2. 2 Beam member loading test
The repair effect of TST-FiSH test was tested on beam specimens
under two-point loading. From the test results of the adhesion test
(conducted in a separate investigation), TST-FiSH using three kinds of fiber
sheets (carbon, aramid, and vinylon) with resin density 66% test cases wereselected. Specimen dimensions are shown in Figure 2, specimen
specifications and test cases are shown in Table 2, and material properties
are shown in Table 3. First, the beam was damaged in shear under primaryloading, then repaired by wrapping TST-FiSH in a single-layer in the shear
span with a 150mm overlap on top of the beam. Secondary loading was
conducted after 6 days curing. Loading was applied one-directionally with
gradual but steady increase. Cracks were observed visually, and load,
vertical displacement, axial reinforcement strain and shear reinforcement
strain were measured.
Strain gauge100
2@150=300

2@75=150

SD295-D630

2@150=30030

2@75=150

SD345-D10

90

90

150

30

100

700

30

30

SD345-D13
5@30=150

100
150

900

Unit：mmFigure 2: Beam specimen dimensions
Table 2: Specimen specifications and test cases for beam member loading test
Specimen
No.
1
2
3
4
5
6
7
8

Axial direction rebar Shear reinforcement
Equivalent height Span
d
a
a/d
Resin
steel ratio
Steel ratio Damage degree Fiber sheet
Material
Material
(mm)
(mm)
(%)
(%)
Nothing
CarbonVinylonLow
Aramid
SD345
SD295A
Hydraulic120
300 2.5
2.8
0.094
D13
D6
Polyurethane
CarbonVinylonHigh
AramidCarbonEpoxy

Table 3: Material properties for beam member loading test
Concrete
Steel
Axial direction rebar
SD345 D13
Shear reinforcement
SD345 D6

Compressive strength(N/mm2)
27.8
Tensile strength
Yield stress2(N/mm2)(N/mm )

Young modulus(N/mm2)2.30×104
Young modulus(N/mm2)374

566

1.80×105

310

462

1.69×105

Two levels of damage were applied to the specimens, following theJapan Road Association specification (JRA, 2007). For low damage degree,
the load was removed when shear reinforcement reached the initial yieldstrain of 1830μ (see Figure 4). This value was determined by the occurrenceof diagonal cracking when the residual crack width W<0.5mm. For highExperimental examination on the repair effect of emergency rapid retrofitting method TST-FiSH

357

October 2009, Incheon, Korea

damage degree, specimens were unloaded at 80% of the maximum load, andthe residual crack width was 0.5mm≦W<2mm.
2.3 Column member loading test
The repair effect and shear capacity of TST-FiSH selected by the
results of the beam member tests were tested by cyclic lateral loading on acolumn member without axial force. The member was fixed at the base withthe top of the member free. Specimen dimensions are shown in Figure 3,
specimen specifications and test cases are shown in Table 4, and material
properties are shown in Table 5. Specimen size and bar arrangement were
decided based on a previous study (Katsuki et al., 1997).
Loading direction

Loading direction

Sheet wrapping

Before repair

After repair

Specimen No.1

Specimen No.2,3Figure 3: Column specimen dimensions
Table 4: Specimen specifications and test cases for column member loading test
SpecimenNo.

Fracture
mode

1

Shear

2

Equivalentheight
d
(mm)

260

Span
a
(mm)

910

Axial direction rebar
a/dMaterial

steel ratio
(%)

SD490
D25

7.8

3.5

flexural
3

SD345
D22

6.0

Shear reinforcement
Material

Steel ratio(%)

Damagedegree

Fiber
sheet

Hydraulic
Polyurethane

NothingSD295AD4

0.072

Aramid
High

Resin

Epoxy
Hydraulic
Polyurethane

Table 5: Material properties for column member loading test
Concrete
Steel
Axial direction rebar
SD345 D22
Axial direction rebar
SD490 D25
Shear reinforcement
SD295A D4

Compressive strength(N/mm2)
29.4
Tensile strength
Yield stress2(N/mm2)(N/mm )

Young modulus(N/mm2)
2.58×104
Young modulus(N/mm2)374

443

1.97×105543

710

1.86×105

320

488

1.84×105

In order to calculate the shear capacity carried by TST-FiSH,
specimen No.1 was repaired without primary loading damage. Specimen No.
2 and 3 compared the conventional epoxy method and the TST-FiSH tounderstand the repair effect after damage. Shear damage by residual crack
width (high damage degree 0.5mm≦W＜2mm) was given to the specimen
by primary loading, and secondary loading was conducted after 100mmwide aramid fiber sheets were wrapped around the shear span with 0mm
displacement. The aramid fiber sheet was overlapped 200mm for each

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New Technologies for Urban Safety of Mega Cities in Asia

specimen. Loading was displacement-controlled by member angle, andmember angle was increased sequentially (1/1000, 1/500, 1/250, 1/100,
1.5/100, 2/100, 3/100 …) until failure. After yield of axial reinforcement,
three additional loading cycles were applied for each member angle.
Cracking was observed by visual inspection, and load, vertical displacement,
axial reinforcement strain, shear reinforcement strain and aramid fiber sheet
strain were measured.

3.

EXPERIMENTAL RESULT AND CONSIDERATION

3.1 Beam member loading test
The calculated maximum stress capacity, experimental value, andfracture mode for beam specimens are shown in Table 6. The shear capacity
was calculated by Equation (2) and Equation (3) (JSCE, 2000).
(2)
Vfyd = Vcd + V sd + Vfd
Where, Vfyd is the shear capacity of member, Vcd is the shear capacity
carried by concrete, Vsd is the shear capacity carried by shear reinforcement,
Vfd is the shear capacity carried by fiber sheet.
Vfd = K ・[ Af ・ffud ( sin αf + cos α f ) / sf ]・ｚ(3)
Where, K is the shear reinforcement efficiency of the fiber sheet, Af is
the total cross section of the fiber sheet in section sf, sf is the disposedinterval of the fiber sheet, ffud is the design tensile strength of the fiber sheet,
αf is the angle of fiber sheets with respect to member axis, z is distance fromthe resultant force of the compressive stress to the centroid of tensile steel.
Table 6: Fracture mode and maximum load for beam specimens
Specimen
No.
1
2
3
4
5
6
7
8

Calculate value
Shear
Flexuralcapacity capacity
(kN)
(kN)

84.5

114.6

Primary loading
Experimental value
Load
(kN)
120.1
126.7
105.6
110.0
125.0
114.1
136.1
120.0

Residual
Damagecrack width
degree
(mm)
0.15
0.20
0.25
0.60
1.10
0.60
0.60

Low

High

Second loading
Calculate value
Experimental value
Shear capacity(kN)

Flexural capacity
(kN)

205.4
151.1
174.2
205.4
151.1
174.2
205.4

153.1
141.5
162.5
167.1
125.0
161.4
165.9

Fractualmode
Shear
flexuralShear
flexuralflexuralShear
flexuralflexural

The load-displacement relationship for specimen No.1 is shown in
Figure 4. In this case, the load was 64.5kN when diagonal cracking occurred,loading continued to increase after yielding of shear reinforcement, and the
maximum load was 120.1kN. The fracture mode was shear fracture after
yielding of the shear reinforcement.
3.1.1 Resinous influence
Load-displacement results of specimen No. 5 and 8 with different
resin and damage degree are shown in Figure 5. Carbon fiber sheets withepoxy and hydraulic polyurethane and high damage degree were used. Bothcases underwent flexural fracture, and the load increased slowly after
yielding of axial reinforcement until the test was finished at displacement
15mm due to crushing of the concrete at the upper edge.

Experimental examination on the repair effect of emergency rapid retrofitting method TST-FiSH

359

October 2009, Incheon, Korea

180
No.1
160

Initial yield strain of shear reinforcement
The yield strain of shear reinforcement

140

Load(kN)

120

High damage degree
80％ of maximum load

100
80
60

Low damage degree
Initial yield strain ofshear reinforcement

40
20
0
0

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15

Disp(mm)Figure 4: Load-displacement (specimen No.1)
In comparison, load increase behavior after secondary loading began
was slightly different, which may indicate that the resinous hardness has an
influence on the stiffness of the repaired specimen. The repair effect(maximum load after repair / maximum load before repair) was calculated
from the maximum loads given in Table 8; for specimen No.5 (TST-FiSH)
it was 1.34 and for specimen No.8 (conventional method) it was 1.38. This
result showed both had a similar repair effect in this experimental condition.
3.1.2 Influence of the damage degree
The load-displacement results for specimen No. 2 and 5 are shown in
Figure 5. The resin used was hydraulic polyurethane with different damage
degree and repaired by carbon TST-FiSH. The displacement at the start ofthe second loading was different due to primary loading, but both underwent
flexural fracture, and the load increased slowly after yield of axial
reinforcement until the test ended at displacement 15mm due to crushing of
the concrete at the upper edge. It was seen that the damage degree did nothave an influence on the repair effect, as found in previous studies.
3.1.3 Influence of fiber sheet typeThe load-displacement result for specimen No. 7 is shown in Figure 5.
In this case, high damage degree was repaired by aramid TST-FiSH. The
behavior of aramid TST-FiSH was similar to carbon TST-FiSH (Figure 8);
it underwent flexural fracture, and the load increased slowly after yield of
axial reinforcement until the test ended at displacement 15mm due tocrushing of the concrete at the upper edge.
The load-displacement result of specimen No. 6 is shown in Figure 5.
In this case, high damage degree was repaired by vinylon TST-FiSH. Shear
fracture was observed, and the load decreased slowly after maximum load
until the test ended at displacement 11mm due to failure of the vinylon fiber.
For the vinylon TST-FiSH, the Young’s modulus of the sheet itself (Table
1) is roughly the same as concrete and lower than the other sheets, so it was
assumed that the repair effect was less because the sheet followed thetransformation of specimen and broke after diagonal cracking occurred.
However, the repair effect (maximum load after repair / maximum load
before repair) calculated from maximum load shown in Table 6 exceeded
1.0, indicating that there was a recovery effect.

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New Technologies for Urban Safety of Mega Cities in Asia

180

180

160

160
140

140

High - Carbon+Epoxy

120

Load(kN)

Load(kN)

120
100

High - CarbonTST-FiSH

80

100

High - AramidTST-FiSH

80
60

60

Low - CarbonTST-FiSH

40

40High - VimylonTST-FiSH
20

20

0

0
0

1

2

3

4

5

6

7

8

9

10 11 12 13 14 15

0

1

2

3

4

Disp(mm)

5

6

7

8

9

10 11 12 13 14 15

Disp(mm)Figure 5: Load-displacement behavior of specimens with different resin anddamage degree (left) and differ fiber sheet types (right)
3.1.4 Comparison of construction time
The application time for the conventional method (specimen No.8)
and TST-FiSH were calculated, and it was found that the conventional
method required around 5 hours, whereas TST-FiSH could be finished inonly 30 minutes – roughly one-tenth the time. This confirmed that TSTFiSH is an effective method for rapid retrofitting after structural damage.
3.1.5 Summary
Summarizing the previous experimental results, it was found that thehydraulic polyurethane resin of resin density 66% could provide the same
repair effect as epoxy resin in one-tenth of the application time. For thefollowing column member loading test, the aramid fiber sheet was selectedbased upon consideration of its application characteristics.
3.2 Column member loading test
The calculated maximum stress capacity, experimental value, andfracture mode for column specimens are shown in Table 7. The calculation
values were calculated by Equations (2) and (3), similar to beam members.
Table 7: Fracture mode and maximum load for column specimens
Calculate value
SpecimenNo

1

Shear capacity(kN)

Primary loading
Experimental
value

Vc

Vs

Vd

Flexuralcapacity
(kN)

-

-

-

331.0

2

110.3

15.6

125.9

163.0

3

110.3

15.6

125.9

163.0

Second loading
Experimental
value

Calculate value

Load
(kN)

Residual
crack
width
(mm)

Vc

Vs

Vf

Vd

-

-

-

113.1

15.6

130.2

258.9

0.5

High

-

15.6

130.2

145.8

0.5

High

-

15.6

130.2

145.8

166.7
(-150.1)
172.8(-160.1)

DamagedegreeShear capacity(kN)

Flexuralcapacity(kN)
292.1(-273.0)229.9(-221.5)218.6(-210.5)

Fractual
mode

Shear
flexuralflexural

3.2.1 Shear capacity carried by TST-FiSH
The load-displacement curve for specimen No.1 with aramid TSTFiSH is shown in Figure 6, with the load at the time of yielding of the outermost axial reinforcement shown as a dashed line. Specimen No.1 shear
reinforcement yielded between 1.5/100 and 1/250 member angle, maximum
load occurred at 3/100 and -2/100, and the fracture mode was shear
compression failure and destruction of web concrete. Loading wascontinued only on the positive side after load decreased, and the aramid
fiber sheet broke when the load suddenly decreased after exceeding 9/100.

Experimental examination on the repair effect of emergency rapid retrofitting method TST-FiSH

361

October 2009, Incheon, Korea

Load-strain curve for specimen No.1 with aramid fiber sheet is shownin Figure 6. The strain meter was installed on the side of the column,
325mm above the base, and the strain meter for shear reinforcement wasalso installed in the same position. Up to the load of 120kN, strain wasapproximately equal for both shear reinforcement and aramid fiber sheet;however, at 161kN the shear reinforcement yielded. After that, strain ofaramid fiber sheet increased continuously, indicating that the aramid fiber
sheet was carrying the shear force after the shear reinforcement yielded. The
strain value at the maximum load was around 12,200×10-6, which was 71%
of the failure strain found in previous study (Nakajima et al., 1997). The
failure mode in this experiment was shear compression failure; the shear
capacity carried by the fiber sheet was calculated by truss theory to be
152.6kN in the plus side and 133.5kN in the minus side. Since these values
exceed the calculated shear capacity (Table 7 Vf = 130.2kN) and shear
reinforcement efficiency, it was concluded that this method provides a safe
estimate of the shear capacity. In addition, this result demonstrates that theshear capacity can be evaluated by the sum of the individual shear capacity
contributions, verifying the past research work (JSCE, 2000).
300

300

200

200

3/100
100
Load(kN)

Load(kN)

100

0Aramid fiber sheet strain
Shear reinforcement strain0

Aramid fiber sheet fracture strain
Shear reinforcement yield strain

-100

-100

-2/100-200-200No.1(AramidTST-FiSH)-300-120 -100 -80 -60 -40 -20

-300
0

20

Disp(mm)

40

60

80

100 120

0

5000

10000
Strain(μ)

15000

20000

Figure 6: Load-displacement curve (left) and load-strain curve for specimen No. 1
3.2.2 Verification of the repair effect
The load-displacement curves for primary loading of specimens No.2
and 3 are shown in Figure 7. For primary loading, both specimen No.2 and 3
showed the same load-displacement behavior, with diagonal cracks atmember angle 1/250, and yielding of shear reinforcement at member angle
1/200. Loading ended when it was judged that high damage degree
conditions were satisfied per 2.2, and the residual crack width was measured
as 0.5mm after ending member angle 1/100. The strain of axial
reinforcement in specimens No.2 and 3 was just before yielding.
The failure conditions after secondary loading are shown in Figure 8,
the load-displacement curves of the second loading for both specimens areshown in Figure 7, and the loads at yielding of the outer-most axial
reinforcement for both specimens are shown as dashed lines in Figure 7.

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New Technologies for Urban Safety of Mega Cities in Asia

300

300

1/200
1/250
1/500
1/1000Load(kN)

100

1/150

1/100

-200

-1/1000-1/100 -1/150

-6

-200

No.2(Armid + Epoxy)-4-2-1/100-100

02
Disp(mm)468No.2(Aramid + Epoxy)-6/100

-300

-8

8/100

1/100
0

-8/100-1/500-1/250-1/200No.3(AramidTST-FiSH)

-10

6/100

100

0

-100

3/100

200

Load(kN)200

10No.3(AramidTST-FiSH)-3/100-300-120 -100 -80 -60 -40 -20

0

20

40

60

80 100 120

Disp(mm)Figure 7: Load-displacement curve for primary (left) and second loading (right)

Figure 8: The failure conditions after secondary loading
The stress capacity of specimen No.2 with epoxy resin and aramid
decreased at member angle ±8/100, and after yielding of the axial
reinforcement displacement occurred along the diagonal crack surface
which was formed during primary loading. The failure condition (Figure 8)
was predominantly due to shear deformation caused by the diagonal cracks
from the primary loading. The fracture mode was likely flexural failure
because the characteristics of shear failure, such as load increase after
yielding of axial reinforcement, breaking of fiber sheet, or destruction of
web concrete (as seen in specimen No.1) were not observed. Loading
continued only on the plus side and after member angle 10/100 the aramid
fiber sheet broke when the failure load was reached. Specimen No.3
repaired with aramid TST-FiSH suffered greater displacement along the
diagonal crack surface formed during primary loading after yielding of axial
reinforcement. The load began to decrease slowly from ±4/100, until it
became less than the yield load at member angle ±8/100. The failure mode
appeared to be flexural failure, the same as specimen No.2, due to the
influence of the diagonal cracks from the primary loading. The repair effectof TST-FiSH for column member with shear damage was confirmed to be
the same as that of the conventional method. Loading continued only on theplus side, and after member angle 10/100 the aramid fiber sheet broke when
the failure load was reached.
When comparing the load-displacement curves for specimens No. 2
and 3, although there is a slight difference in the maximum stress capacity
and the rate of stress decrease, since the failure load is similar it is assumed
that same design stress capacity can be used for both methods. It’s possible

Experimental examination on the repair effect of emergency rapid retrofitting method TST-FiSH

363

October 2009, Incheon, Korea

that this small difference in behavior is due to the constraint effect of thematerials, particularly the epoxy and the hydraulic polyurethane resins.

4. CONCLUSION
This research examined the potential application of the hydraulic resin
using various types of fiber sheets, and the repair effect was confirmed byexperimental testing of damaged and repaired beam and column members,in order to clarify the performance and potential of TST-FiSH. TST-FiSH
could be applied much faster than the conventional method using epoxy
resin. The materials selected for TST-FiSH were hydraulic polyurethane
resin of density 66% and fiber sheet of weight around 300g/m², withfinishing conducted just after water spraying. The shear capacity of RC
members repaired by TST-FiSH could be evaluated as the sum of theindividual shear capacities. Although a small difference in behavior due tothe constraint effect of the concrete was observed and attributed to thephysical properties of the resins, it was concluded that for medium damage
degree TST-FiSH can provide a repair effect similar to that of theconventional method with epoxy resin.

ACKNOWLEDGMENT
This research was supported by a financial grant from the Japanese Ministryof Land, Infrastructure, Transport, and Tourism (MILT) for the research anddevelopment of construction technology. The authors would also like tothank MC Industries, Co., Ltd., Tokyu Construction Co., Ltd., and Mr.
Michael W. Henry for their support.

REFERENCES
Japan Society of Civil Engineers., 2000. Concrete library 101. The repair
and reinforcement guidelines of concrete structure using fiber sheet, JSCE,
Japan. (in Japanese)
Japan Road Association., 2007. Road earthquake disaster measures manual
volume earthquake disaster restoration. JRA, Japan. (in Japanese)
Nakajima, N., Nakai, Y., Watanebe, T., Matsumoto, N., 1997. Shear
behavior of railway viaducts columns strengthened with aramid fiber
reinforced sheet, Proceedings of the Japan Concrete Institute, Vol. 19, No.2,
pp.255-260. (in Japanese)
Katsuki, F., Nakai, Y., Watanabe, T., Moriyama, T., 1997, Experimental
study on deformation capacity of railway viaducts columns using aramid
fiber sheets, Proceedings of the Japan Concrete Institute, Vol. 19, No.2,
pp.1569-1574. (in Japanese)
Suzuki, M., Suzuki, R., Ito, M., Kato, Y., 2008. Development of emergency
retrofitting method using fiber sheet containing hydraulic resin, Proceedingsof the Japan Society of Civil Engineers, Vol. 63, pp. 645-646. (in Japanese)364

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 6

INFORMATION MANAGEMENTFOR DISASTER REDUCTION
1KIMIRO MEGURO and 2SHINYA KONDO

1International Center for Urban Safety Engineering
Institute of Industrial Science, The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp
2
The Great Hanshin-Awaji Earthquake Memorial
Disaster Reduction and Human Renovation Institute, Kobe, Japan

ABSTRACT
Quality and quantity of disaster can be discussed by the relations
between characteristics of hazard as an input, such as magnitude, locationof hypocenter, fault mechanism, etc. in case of earthquake andcharacteristics of the affected region as a system, such as soil condition,
infrastructure and housing condition, politics, economy, religions,education, history, culture, etc. The regional characteristics can be divided
into two groups, one is on natural environment and the other is on social
environment. Also, since activities of people and society are strongly
reflected by time, time related factors, such as season, day of the week, andevent occurrence time, etc. should be considered as a part of the system.
Disaster can be considered as an output of the above mentioned inputsystem mechanism.
While there are seven countermeasures for disaster reduction, namely,“mitigation”, “preparedness”, “prediction and early warning”, “damage
assessment”, “emergency disaster response”, “recovery”, and“reconstruction”. For implementation of all seven measures, “informationand communication” is a key and information management plays essential
role for “information and communication”.
The ideal disaster management measures are to be conducted byproperly balancing these seven measures considering hazard characteristics
and regional characteristics of the target area. In this paper, the authors
sort out important issues on information management and propose theirsolutions for total disaster management to minimize negative impact due tohazards.

1. INTRODUCTION
For total disaster management, there are seven countermeasures.
Figure 1 shows these seven measures, namely, “mitigation”, “preparedness”,“prediction and early warning”, “damage assessment”, “emergency disaster
response”, “recovery”, and “reconstruction”. For implementation of all

365

October 2009, Incheon, Korea

seven measures, “information and communication” is a key and information
management plays essential role for “Information and communication”. The
ideal disaster management measures can be conducted by properly
balancing these seven measures considering both the hazard characteristics
and regional characteristics of the target area.
In this paper, the authors point out important issues on information
management and propose their solutions for total disaster management tominimize negative impact due to hazards.
Risk Management
Preparedness
Mitigation

Prediction and
Early Warning
DisasterReconstruction
RecoveryInformation& Communication

Damage/Impact
Assessment
Disaster Response

Crisis Management

Figure 1: Elements of disaster countermeasuresand total disaster management system
2. CONSTRUCTION OF DATABASE
After a hazard attack, survey on information required by the affected people
and/or people who should take care of affected ones is often carried out
through questionnaire survey and interview survey. Figures 2 and 3 show
some examples of these survey results, however, they are not enough forproper actions. As Figure 4 shows, it is important that from before a hazard
attack to just after, and to recovery and reconstruction stages, and fromnational level to prefecture, city and town, and to citizens’ levels, allactivities by all divisions and information needed for those activities areanalyzed. In this chapter, the method for analysis and database preparedbased on the result of analysis will be introduced.
2.1 Information on Disaster Response Activities for Analysis

In Japan, we had an earthquake with the magnitude of 6.8 called the2004 Mid Niigata Prefecture Earthquake in the central part of Niigata
Prefecture on October 23, 2004. The death toll and injured due to thisearthquake was 68 and 4,805, respectively. The total number of heavily andpartially damaged houses and buildings was approximately 16,000. The
records of disaster response activities by the Niigata Prefectural
Government during this earthquake disaster were used for analysis. The
records summarized by the Niigata Prefectural Government employees

366

New Technologies for Urban Safety of Mega Cities in Asia

contain time series actions of each section with actors and their start andfinish times.

Information required
Aftershocks

Information required
Aftershocks

Situation on family and friends

Recovery on lifeline services
Recovery or conditionof road and traffic system
Food and emergency supply
for affected life
Public bath service

Magnitude and locationof the earthquake
Overall earthquake damage
Recovery on lifeline services
Safety of own house
Situation on fire
Recovery or conditionof road and traffic system
Safe evacuation
and refugee camp
Food and emergency supply
for affected life
Info. whose needs
increased

Place of food and water supply
Safety of own house
Overall earthquake damage
Situation on family and friends
Stores opened
Info. whose needs
decreased

Figure 2: Changes of needs of information
after the 1995 Kobe earthquake
Time (No. of days since the earthquake)
DamagesituationRoad
condition
Evacuation
situation
Gas supply
Water supply
Temporary
housing
Crime
prevention
Housing
consultant

Figure 3: Changes of information that Niigata Prefecture governmenthas been disseminating through Web
after the 2004 Mid Niigata Prefecture Earthquake
2.2 Activities and Required Information

In order to provide appropriate responses to the various tasks at
appropriate times, organizations do not respond to any single situation, butinstead they take an overview of the entire situation. Kondo and Meguro [1]have proposed an environment for provision of appropriate responses (seeFigure 5). People should improve their temporal and spatial grasp of theenvironment and what will happen after the disaster (imagination), as well
as sort out potential problems (analysis), design and develop
countermeasures (design & development), implement disaster drills(implementation), and assess each element (assessment).

Information Management for Disaster Reduction367

October 2009, Incheon, Korea

Activities&
Divisions

Before DisasterNationallevel

After Disaster

Before Disaster

Prefectural
Level

After Disaster

Before Disaster

City, Town
Level

After Disaster

Before DisasterCitizens

After Disaster

Before Disaster

Disaster

After DisasterFigure 4: Disaster Information Image of Disaster Information Database

Who?

Job
analysis
What?

Workload
Evaluation

Information
management

How much?

What kind ofInformation?

Constitution

MutualRelationsFigure 5: Environment for provision of appropriate responses [1]Figure 6 shows a series of activities as time goes that need information(A) and (B). Also, actor organization/division and required accuracy on theinformation are shown in the figure. In order to prepare this figure using realdata, we should make clear the relations between information and activity.
However, there is no person who can trace activities from the viewpoint of
information required for each activity. Therefore in the study, we picked up
all works from large scale and broke down these works up to concrete
actions by interview survey from all divisions related disaster response as
shown in Figure 7 (a). After getting all concrete actions, we asked thepeople at each division and could get information and accuracy required foreach action, and its provider division. About required accuracy of theinformation, there are three factors; quantity, location, and time. Accuracy
on these three factors becomes quite different with actor
division/organization, time, and action. When we can prepare all relations
among action, required information, and its accuracy and provider, wefinally can trace all activities from the viewpoint of each required
information as shown in Figure 7 (b). Adopting this approach, we can makedisaster information matrix and when we make disaster information platform using this concept, each division of all levels from national to city andtown levels can get necessary information in favorite time with required
resolution. Therefore, with this plat form system, people belonging to local
governments don’t have to report damage situation to the higher level

368

New Technologies for Urban Safety of Mega Cities in Asia

governments. With the following chapters, we will explain this approach
using real data.
2.3 Database Specifications

It is necessary to organize the input items for disaster response
analysis from the five viewpoints. There were 12 attributes in this study as
shown in Figure 8: responsible organizations, services provided, actions
taken, terms of measurement, start and finish times of events, workloads,
necessary information, division(s) to access information, output information,
division(s) of information destinations, and related actions. If some records
lacked certain attributes, details from the 2004 Mid-Niigata Prefecture
Earthquake were supplied through interviews with Niigata Prefectural
Government employees and reference materials [3 – 6] of this earthquake.
For sorting out potential problems, people should analyze the current
disaster from five viewpoints, i.e. “Constitution”, “Job analysis”, “Workload
evaluation”, “Information management”, and “Mutual relations.”“Constitution” means defining each group’s role, depending on how thesituation unfolds after the hazard attack. “Job analysis” means comparingneeds in the disaster area with what the organization should do. “Workload
evaluation” means estimating the quantity of work to be done for effective
use of limited resources (i.e., people, goods, capital, and information).
“Information management” means not only obtaining, controlling,
communicating, sharing, and using information to do work, but managing
cooperation with outside organizations. “Mutual relations” means analyzing
disaster response activities from the multiple viewpoints described
previously.
If the organization considers countermeasures based on these analyses,
each person’s actions will be linked so that things will be organized in atimely fashion with spatial efficiency. However, most existing reports lackanalysis from these five viewpoints. In a previous paper, the authors
proposed “A New Style Disaster Information Database,” which was asystem for multilateral analysis and assessment of a database consisting ofnewspaper articles, reconnaissance reports, compilations of lessons [2], anda new method for disaster response assessment using a disaster information
database constructed based on current available systems, such as fax
machines [1]. This system and method together form an environment thatprovides information to all people for the development of their mental
images of the situation after disaster struck. However, they do not have thefive viewpoints to analyze the organization’s disaster response. In this study,
the authors propose an environment to improve disaster management of theorganization in a disaster-free period. Specifically, the records of disaster
response activities in past disasters were analyzed from five viewpoints(constitution, job analysis, workload evaluation, information management,
and mutual relations), issues for improvement in disaster management of theorganization were sorted out, and the contents and structure of
improvements were identified.

Information Management for Disaster Reduction369

October 2009, Incheon, Korea

Which
Organization?

Which
Organization?

Which
Organization?

Which
Organization?

Info.
(A)

req. Ac

Which
Action?

Which req. Ac
Action?

req. Ac

Which
Action?

Which
Action?

req. AcNo person can trace disaster response activities from the viewpointof information required. Therefore, ・・・・・
Which
Organization?

Which
Organization?

Which
Organization?

Which
Organization?

Info.
(B)

req. Ac

Which
Action?

Which req. Ac
Action?

req. Ac

Which
Action?

Which
Action?

req. Ac(req. AC: Required Accuracy)

Figure 6: Activities are traced from the viewpointof each information required for the activity
Time from the event

Pick up all actions
from general to detail

HazardOrganization Work A

Work B

Work C

Division (D1)
Sub
W-A
1-2

Sub
W-A
1-1

Sub
W-B
2-1

Sub
W-B
2-2

Sub
W-C
3-1

Sub
W-C
3-2

ActionActionActionActionActionActionActionActionAction

１-1-1

１-2-1

１-2-2

2-1-1

2-2-1

2-2-2

3-1-1

3-1-2

3-2-1

Sortingproblems

1hr

３day

1day

1week

(a) Break down of works
T im e fro m th e e v e n t
1hr

1day

3day

1week

H a z a rd
A c tio n

A c tio n

A c tio n

A c tio n

A c tio n

A c tio n

A c tio n

A c tio n

A c tio n

１ -1 -1

１ -2 -1

１ -2 -2

2 -1 -1

2 -2 -1

2 -2 -2

3 -1 -1

3 -1 -2

3 -2 -1

In fo .

In fo .

In fo .

In fo .

In fo .

In fo .

In fo .

In fo .

In fo .

A ,B ,..
C , D ,E .
(+ re q .A C ) (+ re q .A C )B ,C ,..
C ,D ,..
B ,C ,E ..
(+ re q .A C ) (+ re q .A C ) (+ re q .A C )A ,C ,E ,..
B ,D ,F ,..
A ,B ,..
C ,E ,G ,..
(+ re q .A C ) (+ re q .A C ) (+ re q .A C ) (+ re q .A C )p ro v id e r p ro v id e r p ro v id e r p ro v id e r p ro v id e r p ro v id e r p ro v id e r p ro v id e r p ro v id e r
a ,b ,..
c ,d ,..
b ,c ,e ..
a ,c ,e ..
b ,d ,f..
a ,b ,..
c ,e ,g ..
b ,c ,..
c ,d ,e .. .
re q . A C : R e q u ire d A c c u ra c y
W h ic h
O rg a n iz a tio n ?
(D 1 )

W h ic h
O rg a n iz a tio n ?
(D ? )

W h ic h
O rg a n iz a tio n ?
(D 1 )

W h ic h
O rg a n iz a tio n ?
(D 1 )

In fo .
(A )W h ic h
A c tio n ?
1 -1 -1

re q . A c

W h ic h
A c tio n ?

re q . A c

W h ic h
A c tio n ?
2 -2 -2

re q . A c
re q . A c

W h ic h
A c tio n ?
3 -1 -2(b) Activity traceability by required information

Figure 7: Method for trace of activities from the viewpointof each information required for the activity
370

New Technologies for Urban Safety of Mega Cities in Asia

In this research, the records of the Niigata Prefectural Government’s
disaster response activities during the 2004 Mid-Niigata Prefecture
Earthquake were collected and used for analysis from five viewpoints. The
validity of the analysis from the five viewpoints was verified, and lessons of
the organization’s disaster response were summarized.
ID

Responsible organization(s)Service

1 Civil Engineering, Building and Housing Construction of temporary housing

ID

Action1

Research construction site for temporary housing

ID Term(s) of measures Time to start Time to finish
1

Emergency

100 (hours)

ID

Input
information

Division(s) toaccessinformation

1

No. ofhouseholds withrefugee

Life andenvironment
division

180 (hours)

Outputinformation

Workloads
10 (division x day)

Division(s)for information
destination

Candidate site
General affairs division,for
Administrative
temporary housing
promotion officeID

Related action

1

Budget for temporary house construction

Figure 8: Specifics of the database

3. ANALYSIS OF THE ORGANIZATION’S DISASTER RESPONSE
BASED ON THE DATABASE
In this section, the organization’s disaster response is analyzed using thedatabase. In this study, “Analysis” is defined as “breaking combined
operations down into their constituent parts and sorting those constituentsand their characteristics.” The current state of disaster response can beunderstood from an analysis of all operations, but problems are not sortedout quickly. Analysts (the authors and staff who responded to the disaster inthis study) determine the constituents and characteristics of the disaster
response and discuss its validity from the results of analysis. In addition,
problems emerged as gaps between an ideal situation and the actual
situation.
3.1 Constitution
After the 2004 Mid-Niigata Prefecture Earthquake struck, 17
departments were established under the Niigata Prefectural Emergency

Information Management for Disaster Reduction371

October 2009, Incheon, Korea

Operation Center (EOC). EOC meetings were held as needed. Some groups,
which consisted of several departments, reported on the situation at the time.
Table 1 shows the evolution of the structure. Many groups were
established in the EOC meetings: five groups in the first step (October 27,2004), two groups in the second step (October 31, 2004), and one group in
the third step (November 13, 2004). The reason for this was the need toprovide careful service. In the fourth step (December 24, 2004), all groups
except five were disbanded.
Table 1: Evolution of the Niigata Prefectural EOC structure

Structure

Date

Local plan fordisasterprevention
Headquaters
commission

First
→

Second→2004/10/27

Third
→

2004/10/31

2004/11/5→

Headquaters
commission→

Headquaters
commission→

Headquaters
commission

General affairs→

General affairs→

General affairs→

Countermeasure→

Countermeasure→

Countermeasure→

Bulletin→

Bulletin→

Bulletin→

Ministry on-site
support team→

Ministry on-site
support team

→

8

→

Headquaters
commission

General affairs

5→

General affairs

Countermeasure

15→ Countermeasure

Bulletin

5→

Bulletin

Ministry on-site
support team40→

Dissolution

Liaison to ministry → Liaison to ministry → Liaison to ministry → Liaison to ministry→ Control of SDF→ Control of SDF
Control of SDF→ Liaison to SDF→ Liaison to SDF→ Liaison to SDF
Liaison to SDF
Liaison to disasterprevension agency→

Lifeline→

Liaison to disasterprevension agency
Lifeline
Rescue→Liaison to disasterprevension agency

Lifeline→ Rescue→→

Lifeline→ Rescue→Information on
evacuation center→

Supply of food→

Supply of food→

Livingware
Liaison toGoverners

Liaison to disasterprevension agency→

Information on
evacuation center

4th
Numbers →(Max)
2004/12/24

Information on
evacuation center

Supply of foodRelief goods and→logistics
Liaison to→Governers

Dissolution
Dissolution→ Dissolution
→

60
15

→

10

→

Dissolution

8
16

→
→

Dissolution
Dissolution

5→

Dissolution

18

→

50

→

Dissolution
Relief goods
and logistics

10→

Dissolution

265

SDF: Self Defense ForceIn other words, the Niigata Prefecture EOC meetings decided on
countermeasures that could be implemented from soon after disaster struck
to two months after the Mid-Niigata Prefecture Earthquake. Thus, changes
in the organization’s structure proportional to changes in the disasteraffected community were made.
3.2 Job Analysis
Job analysis means the breaking down and refining of work to leadplanning operations to action. The first level was the EOC’s work as listed
in regional disaster prevention plan. The second level was the division’s
work listed in the regional disaster prevention plan. The third level wasintermediate tasks between the second and fourth levels. The fourth level
was concrete action. For the Civil Engineering Bureau Building andHousing division, the first level was “Housing” and the second level,“Construction and provision of temporary housing” consists of the thirdlevel: “Procuring of site,” “Budget,” “Manufacturers,” “Dwellers,” and“Orders,” as shown in Figure 9. In addition, the fourth level, “Procuring,”
consisted of “Households of refugees,” “Damage to construction sites,” and“Number of collapsed houses.”372

New Technologies for Urban Safety of Mega Cities in Asia

1stHousing

2nd

3rd

4th

DisasterWork structuring

Time from the event

Time setting

Construction & provision of
temporary housing
Procuring of site
Households of refugees
Damage of construction sites
No. of collapsed house

BudgetMaterial procurement
Cost assessment

Manufacturers
Dwellers
OrdersFigure 9: Job analysis (Civil engineering bureau, housing construction)
3.3 Workload Evaluation
In this section, each type of work to be done was quantified. Thiswas done by compiling the duration of first level works, with eight hours
equaling one unit per day. Figure 10 shows the prefectural staff’s workload
at each first level. “Setting and management EOC” was the largest categoryof work in terms of quantity. “Public establishment” and “Agriculture,
Forestry and Fisheries” are the second and third-largest categories of workin terms of quantity, respectively. The features of the 2004 Mid Niigata
Prefecture Earthquake were collapsed houses, blocked roads, isolated
settlements, and floods due to landslides. Local structures – rice terraces andcarp ponds – were damaged in Yamakoshi village. Rice terraces fell under
the category of “Public Establishments,” carp ponds under the category of“Agriculture, Forestry and Fisheries.” The amount of work to be done byeach division was analyzed for clarification of the division’s workload.
Table 2 is an analysis of the responsibility of the Living Environment
Bureau. The main work of this bureau was the following: A) Setting andmanagement EOC, C) Debris and human waste, and I) Volunteers. These
work categories were listed on the local disaster prevention plan. Thisbureau also worked with other bureaus’ main work categories, such as J)
Relief money and K) Commerce and industry. This analysis included eachbureau’s work, both its main work and complementary work. The work
categories listed in the local disaster prevention plan and carried out in realsituations were compared and analyzed. Figure 11 is an analysis of the Civil
Engineering Bureau’s work, where the x-axis is the organization responsible,
the y-axis is time from the event, and the z axis is the number of work
categories, with the local disaster prevention plan on the left and the realsituation on the right. The plan did not have a concept of a timeline;
therefore, related records were used in setting the times. This analysis

Information Management for Disaster Reduction373

October 2009, Incheon, Korea

showed concrete actions taken in the implementation of the plan, as well as
unplanned work. Table 3 is an analysis of unplanned work. Local
government staff should not only know the tasks listed on the plan, but also
recognize “Routine work,” “Conclusion of agreements,” “Assistance toother divisions,” “Publication and notices,” and “Demands and requests.”(division x day)NＮ
Others
その他

M Send staffs to
M 市町area
村へ派遣
affected・Analysis of all prefectural staffs’ disaster response for two months

LＬ
Reconstruction
災害復興

KKCommerce
and industry
商工業対策

J JRelief
money
義援金

I IVolunteer
ボランティア

HＨ
Housing
住宅対策

G Agriculture, Forestry
G Fisheries
農林水産業対策
andFＦPublic
establishment
公共施
設等対策

EＥ
Education
教育対策

D Supply of food andＤ食
糧供給・救援物資
reliefgoods
C Debris and human
Ｃ 廃棄物・し尿処理等
waste

BBHealthandwelfare福祉保健対策

AASetting
and
県災害
対策本部の
management
設置EOC
・運営

7000 6533
6000
5000
4176
3687
4000
3129
2592
3000
1395
1377
1343
2000
1285
826
703
618 680401
1000
0Figure 10: Prefectural staff’s workload for each first-level task

Table 2: Analysis of the responsibility for each divisionof the Life and Environment Bureau
Crisis management
Environmental plan
Environmental measures
Life
Nuclear safety measures
Fire difense
Promotion of gender equality
Debris measures
Cultural administration
Total

A
B
52 0
125 1
124 5
81 0
142 0
676 0
4 0
0 0
18 2
1222 8

C
0
64
75
0
0
25
0
523
0
687

D E F G H
47 0 0 0 0
1 0 0 7 0
2 0 0 0 0
5 0 0 0 0
0 0 0 0 0
4 0 0 0 0
2 0 0 0 0
0 0 0 0 0
0 0 4 0 0
61 0 4 7 0・Analysis of all prefectural staffs’ disaster response for two months

I
0
13
9
265
0
0
11
0
29
327

J K L M0 0 0 01 0 0 50 0 0 00 8 0 00 0 0 00 0 0 40 0 0 00 0 0 00 0 0 0
1 8 0 9

N
0
20
0
0
139
133
53
0
0
345

(division * day)

3.4 Information Management
Disaster response, from information managed at the time, has been
analyzed as follows. The work analyzed in Section 3.2 was “set-related”
information. Information and work did not always have a one-to-one
relationship. Figure 12 shows the result of associating related information
with structured second-level work, such as “the Construction and provisionof temporary housing.” Related information was separated into input andoutput as seen in Figure 13. Based on these processes, information-related
disaster response was arranged on a timeline.

374

New Technologies for Urban Safety of Mega Cities in Asia

Records ofdisaster response

Regional disasterprevention planZ
No. of works

33
26

12

Y

10

Time from the event

19

28
23

22

21 19

17 17

X

Responsibleorganization

6 6
4
3
2

2

20

0
Total

Total

Supervision

Supervision
Maintenance

Maintenance
515

Urban policy

Urban policy

Sewage system

Sewage system

Site & land use

Site & land use

10

Building housing

Building housing

0

Urban development

Urban development

River development

River development

River management

River management

5

Road construction

5

Road construction
Road maintenanceRoad maintenance
Erosion & torrent control
Technical management0

Erosion & torrent control

0

Technical management

Figure 11: Analysis of Civil Engineering Bureau’s work
Table 2: Unplanned work categories
2nd level
Carrying in and out relief supplies
Classification

ActionDisaster
response

Carry in relief supplies at Niigata Airport

Routine work

Provide house map to related divisions

Conclusion ofagreements

Conclude collaboration agreement with prefectural land development
corporation

Prepare rice ball at parking

Assistance to Assistance to Nagaoka branch officeother divisions Assistance to empty room information center
Publicationand notices

Demand andrequests

Notify regional agency of case example of site acquisition in the 1995 Kobe
earthquake disaster through written statements
Notify regional agency of site acquisition at disaster area
through a written statement
Go off to MLIT to demand special national taxation measures
for site acquisition
Request site office outside disaster area to assistance site acquisition
Support to respond to the media (Prime Minister inspection)

With the introduction of this process into the entire organization,
information regarding each division’s needs was arranged on the timeline(see the upper part of Figure 14). Which section needs information andwhich section provides information were focused on and arranged on atimeline. The lower part of Figure 14 shows an example of focus on“Refuge information.”In this study, the above method of analysis was called “information
traceability.” “Information traceability job analysis” focuses on “Refuge
information” and “Road damage information.” “Information traceability job
analysis” was an analysis of providers, users, and times for information use,arranged in a table. Work related to taking refuge was not routine work andInformation Management for Disaster Reduction375

October 2009, Incheon, Korea

was work related to various bureaus. Road damage information was used byvarious work categories.
Responsible organization
Related information

Construction & provide temporary housing
Procuring of site
Civil engineering,
Building andhousing

Households of refugee

RefugeeDamage of construction site

Lifeline

No. of collapsed house

Collapsed house

BudgetGeneral affairs,
Finance

Civil engineering,
Building andhousing

Material procurement

Material

Cost assessment

Site No. of construction

Manufacturer

Manufacturer No. of construction

Dweller

Refugee No. of construction

Order

ManufacturerSite
No. of construction

Figure 12: Result of associating related information
with structured second-level work

Input

1. Arrangement of works
according to time-line

Time from the event

No.1 (2nd level)

Output1-1 (3rd)

Info A

1-1-1 (4th)Info A’

Info B

1-1-2 (4th)Info B’

Info C

Info C’

1-1-3 (4th)

1-2 (3rd)

Info D
Info E

1-2-1 (4th)1-2-2 (4th)

1-3 (3rd)

Info F Info G
2. Set related
information

Info H
Info I

Info D’
Info E’
Info F’ Info G’

No.2 (2nd level)
2-1 (3rd)

Info H’

2-1-1 (4th)2-1-2 (4th)InfoInfoInfoInfoInfo
InfoInfo
Info
A BC H D I EF

Info I’

3. Arrangement of informationaccording to time-line

Figure 13: Arrangement of information by division
Figure 15 shows example of “job analysis from information
management.” The upper table is “Refuge information.” and he lower one is“Road damage information.” We have focused on 12 hours after theearthquake struck; refuge information is only used for damage surveys on
shelters. Road damage information was used for early works, such as
damage surveying and traffic regulating, setting up detours for transporting
relief supplies, and surveying isolated settlements when making surveys on

376

New Technologies for Urban Safety of Mega Cities in Asia

earthquake victims. Such work was needed for the working out ofprefectural policy. Therefore, it was necessary to improve the sharing ofroad damage information. Figure 16 shows the arrangement of work and thedivision responsible using refuge information from the timeline. Various
divisions provide service to refugees. Based on this figure, the relationships
among divisions, which were not listed in the local disaster prevention plan,
were shown.
Arrangement of division’s
information according to time-line

DisasterThe
secretarial
office（Refuge）

Civil
Engineering,
Construction

Info
B

Info
C

Info
D

Info
E

Info
D

Info

（Refuge）（Refuge）

Info
I

Environmental Health

Info
D

Info
G

Info
H

Debris

Info
C

Info
（Refuge）

Info
C

Info
B

Info
E

Info

Info

Info

Municipality（Refuge）

Time from the event（Refuge）

Info
F

Info
B

（Refuge）

Info
B

Info
G

Info
H

Info
B

Info
E

Info
（Refuge）

Info
C（Refuge）

Info（Refuge）

Info
H

Info
B

Info
F

（Refuge）

Info
D

Info
E

Info
H

Info
B

Info
C

Info

Info

Info

Info

Information trace
WHO？
Providers

4th level

WHO？

1-1-1

4th level

2-2-2Time fromthe eventInfo(Refuge)

Users
WHO ?

4th level

1-2-3

WHO？

4th level

3-1-2

Figure 14: Information traceability
Figure 17 is an analysis of the effect of information sharing. It wasapparent from the “information traceability job analysis” that different
divisions collected the same information at different times. It was assumed
that the information system would have shared refugee information with the
Niigata Prefectural Emergency Operation Center. The effort of collecting
information had therefore been decreased. By collecting information early,
logistic support, such as the provision of heaters and medicine and thepromotion of same via the media, could be done earlier. In other words,
information sharing was not for the good of disaster response organizations,but for the good of the victims.

Information Management for Disaster Reduction377

October 2009, Incheon, Korea

RefugeDamage survey
on shelter

12hrs. afterRoad damage
Damage survey
Traffic regulation
Set up diversion
Transport relief supply

Arrangement of works which need
information according to time-line

Survey isolated settlement

Figure 15: Job analysis from information management

RefugeDamage survey
on shelter

Education bureau
Cultural administration Health and Welfare Health measures
Enforced education
Higher education
Support to prepare hot meals General policy planning
Financial affairs
Collecting information
Lifelong learning promotion Living environment Debris measures
General affairs
Promote media at shelter
WelfareHealth and PhysicalSet temporary toilet

Agriculture, Forestry and Fisheries
Fisheries

Research on
affected farmer
Health and Welfare Health measures

Heath management on shelter

Living environment Debris measures

Living environment
Promotion of gender equality

Research the needs offemales on shelter

Rescue suffer from isolated settlement
Debris disposal
Enterprise
General affairs, attraction of enterprises

Food aid
Health and Welfare
Health measures

Living environment
Debris measures

Closing shelter project

Request Health and Welfare
garbage truckHealth measures

General policy planning
Accommodation

Actual condition
Make up amount demand Health and Welfare survey on shelter
Health measuresof daily essentials
Health check Medicines distribution
Living environment Fire defense

Gas canister distribution
1day

3days

1week

Education bureau
Financial affairs

Disasterassessment
1month3months

Figure 16: Information traceability job analysis
3.5 Mutual Relations
In this section, the relationship between information providers andreceivers was arranged with focus on types of information. Figure 18 shows
an example focus on refuge area information. The left side references thedivision providing and reporting information. The upper portion references
the divisions needing and receiving information. In this study, this figure
was defined as an input-output information matrix. From Figure 18,
divisions of the Education Bureau provided information to General Affairs.
This division edited information and provided it to the national government.
Figure 19 shows input-output information matrix- related road damage
information. The Civil Engineering Bureau’s Road Management Division

378

New Technologies for Urban Safety of Mega Cities in Asia

received this information not only from the Road Construction Division but
also from related outside organizations, such as municipalities and the
MLIT Regional Development Bureau. This division edited and controlled
information and provided it to the prefectural EOC, the city and national
governments.
In light of the above results, it was possible to improve theenvironment-related outside organizations and central division for
information management with arrangement of divisions providing or
receiving types of information. It was necessary to construct relationships
with related organizations and to learn information management.
Refuge (Actual)
Health and Welfare, Health measures

Different division collected same
information at different term.
Living environment, Fire defense

Collecting information
earlier, logistic support
can be done earlier

Health and Welfare, Welfare of handicapped

Information
sharing(No. of refugee)

Decrease the work ofcollecting information

Provide heater,
medicines
Promote media

Refuge(Improvement)

Figure 17: Effect of information sharing
Information inputDivision needing and receiving information
教
育庁 General
Education bureau
人
事
委
員
会
事
務
局
土
木
部 Municipality
output matrix
General
Debris Personnel Urban Municipality
各
市
町
村Gov.
国
affairs
H保
&体
P課廃
生
涯
学
習
推
進
課
W
CA
EE
HE
FA
LLP
文
化
行
政
課義
務
教
育
課高
等
教
育
課
財
務
課
総
務
課
福
利
課
健
育
棄
物
対
策
課
事
務
局
総
務
課
都
市
政
策
課
affairs(Refugee)
Cultural文
化行
政課
administration
Enforced
義務教
育課
education
Higher高等
教
育課
education

Financial
財務課
affairs

教
育庁
Lifelong learning
生
涯
学
習
推
進
課
promotion

○
A
b
○
A
b
○
A
b
○
A
b
○
A
b

Health and
保
健
体
育
課
Physical

○
A
ｂ

○
A
ｂ

General総務課
affairs
Welfare
福
利
課

○
A
b

○
A
b
○
A
b

Figure 18: Input-output information matrix (refugees)

Information Management for Disaster Reduction379

October 2009, Incheon, Korea
Division needing and receiving information

総合政策部
総務部
土木部
保健衛生部
教育庁 人事委員会事務局
農林水産部
災害対策本部 各市町村
保健体育課事務局総務課 調整課 市町村合併支援課国際交流課交通政策課 管財課 広報広聴課 監理課 建築住宅課道路管理課道路建設課 林政課 福祉保健課生活衛生課

教育庁

保健体育課

Civil engineering,
Road management

人事委員会事務局 事務局総務課

EOC

国

各地域機関

北陸地方
道路公団 AA交通
整備局

BB汽船 CC自動車 DDバス協会

Municipality
Government

調整課
市町村合併支援課

総合政策部
国際交流課

Edit,
Control

交通政策課
管財課

○
B
b

Input

総務部
広報広聴課
○

監理課

A
b

建築住宅課
Civil
engineering,
土木部
道路監理課
Road management○
Cｂ

Provide

道路建設課
Road construction
農林水産部

○

○
B
b

A
b

○

○

A
b

A
b

○

○

○

A
b

A
b

A
b

○
A
b

○
A
b

○

林政課

A
b

福祉保健課
保健衛生部

Relational outsideorganizations

生活衛生課
災害対策本部
各市町村
Municipality

○

○

○

A
b

A
b

A
b

国
Government
○

各地域機
関
Regional
agencyAb○

Hokuriku
RD
北陸地方整備
局

A
b

○

道路
JH公団
AA交通
A transportation

Civil engineering bureau,road division managed
information of road damage

A
b

○

○

○

A
b

A
b

A
b

B Steam
BB汽船
ship
CC自動車
C transportation
DDバ
ス協会
D Bus

○
A
b

○
A
b

○
A
b

Information
input-output matrix(Road damage)

Figure 19: Input-output information matrix (Road damage)

4. CONCLUSIONSIn this study, for implementation of proper disaster management, we havemainly done two issues related disaster information management. One is a
proposal of a new approach to make clear the relationship among activities
for disaster reduction in different time phases, actor organizations/divisions,required information, its accuracy and providers in order to make efficientdisaster information matrix. Adopting this concept, we have proposeddisaster information plat form. With this system, damage data collection andreport systems become efficient and quite different from conventional one
as shown in Figure 20. As Figure 21 shows, when disaster relatedorganizations had this system, efficient information sharing could be done
and disaster response activities might be smoother and more efficient.
The other is that we have proposed an environment to improve disastermanagement of organizations in a disaster-free period. To do so, the recordsof the Niigata Prefectural Government disaster response activities during the2004 Mid-Niigata Prefecture Earthquake disaster were analyzed from five
points of view (constitution, job analysis, workload evaluation, information
management, and mutual relations). Results are shown below.
z
z

380

From the viewpoint of constitution, changes in the Niigata Prefectural
Emergency Operation Center’s structure proportional to changes in thedisaster-affected community were cleared.
From the viewpoint of job analysis, the work divisions listed in theregional disaster prevention plan were broken down and refined for
putting planning operations into action. This analysis enabled
inexperienced people to get a grasp of the time required to carry out theworks.

New Technologies for Urban Safety of Mega Cities in Asia

z

z

z
z

z
z

The workload of each type of work was quantified. The amounts arecalculated by compiling the duration of first level work, with eight
hours equaling one workday. This analysis included both the main workand complementary work of each bureau.
The works categorized in the local disaster prevention plan and carriedout in real situations were compared and analyzed. This analysis
showed concrete actions to be taken to in the implementation of theplan, and also shows unplanned work.
From the viewpoint of information management, which section needs
information and which section provides information were focused on
and arranged on a timeline.
This analysis showed that the relationships between divisions, which
are not listed in the local disaster prevention plan, was shown, and theeffect of information sharing was not for the good of disaster responseorganizations but for the good of the victims.
From viewpoint of mutual relations, the relationships between
information providers and receivers were arranged in a matrix with thefocus on information input-output.
From this matrix, it could be understood that it is possible to improvethe environment-related outside organizations and central division of
information management with arrangement of divisions providing or
receiving types of information. It was necessary to construct
relationships between related organizations and to learn information
management.
National government

Conventional

Prefectures

Cities and Towns
Sections

Large human resour
and long time are req(Data collection
and summary makinof each level)

Lifeline utilities(Power, gas, telephone)

Damage information

National government

With Disaster Information PF and DB
Prefectures
Cities and Towns

Necessary information with required resolution

Disaster Information PF and DB
Sections

Lifeline utilities(Power, gas, telephone)

Damage information

Figure 20: Changes of damage data collection and reportamong disaster related organizations
with and without disaster information plat form

Information Management for Disaster Reduction381

October 2009, Incheon, Korea

Information of
Hospital
Power outage
area

Traffic JamFire

After Dr. I. Noda

(after Dr. I. Noda)
Figure 21: Disaster information sharing using disaster information plat form

REFERENCES[1] S. Kondo and K. Meguro: Development of a New Method for Disaster
Response Assessment Using Disaster Information Obtained byCurrent System, JSCE Journal of Earthquake Engineering, Vol.28,
2005.
[2] S. Kondo and K. Meguro: Development of New Style Disaster
Information Database for Implementation of Efficient Disaster
Countermeasures, Journal of Social Safety Science, No.4, pp. 261-266,
2002.
[3] Niigata Prefecture: The local disaster prevention plan –Earthquake
measures–, 2004.
[4] Niigata Prefecture: Information about the Mid-Niigata Prefecture
Earthquake in 2004, http://www.pref.niigata.jp/content/jishin/jishin
1.html[5] Fire and Disaster Management Agency: The Mid-Niigata Prefecture
Earthquake in 2004, http://www.fdma.go.jp/concern/index.html[6] Disaster Reduction and Human Renovation Institution: Studies on the
Niigata Chuetsu Earthquake Disasters of 2004, 2005.

382

New Technologies for Urban Safety of Mega Cities in Asia

DEVELOPMENT OF LIFE CYCLE
MANAGEMENT SYSTEM FOR OPEN-TYPE
WHARF
EMA KATO and MITSUYASU IWANAMIPort and Airport Research Institute, Japankatoh-e@pari.go.jp
HIROSHI YOKOTA
Hokkaido University, Japan

ABSTRACTThe authors have proposed the strategic maintenance method for port
facilities based on the life-cycle management (LCM) concept. In this paper,
the fundamental concept of the computer-based program to formulate themaintenance plan for an open-type wharf based on the LCM system wasdiscussed. The proposed program was composed of 4 main components in
the LCM system: inspection, assessment and prediction of performance, andimplementation of appropriate intervention. The program should be
improved by accumulating further inspection data and experiments;
however, the authors expect that rational and effective maintenance would
be realized by the results of this research and subsequently the life-cycle
cost reduction and performance maximization could be attained.

1. INTRODUCTIONPort and harbor facilities generally face severe environmental conditions
compared to other infrastructure. They often tend to suffer performancedegradation during their service period due to various reasons including
materials deterioration and damage of structural components. Therefore, thefacilities need to be maintained systematically and appropriately so as toprevent them from failing the performance requirements during their service
period. According to the Ministerial Ordinances on the Technical Standards
for Port and Harbour Facilities revised on April 2007, the basic principles offacility maintenance and maintenance procedures (method, content, timing,
frequency and procedure of inspection, assessment, prediction andcountermeasure/intervention) should be stipulated in advance in a
maintenance plan that conforms to series of basic maintenance proceduresin order to ensure effective maintenance. As reference work for preparing
maintenance plans, the Guidebook for Preparation of Port and Harbor
Facility Maintenance Plan (Ports and Harbours Bureau, 2007) and Manualon Maintenance and Rehabilitation of Port and Harbor Facilities (Port andAirport Research Institute, 2007) were published.

383

October 2009, Incheon, Korea

The authors have proposed the strategic maintenance method for port
facilities based on the life-cycle management (LCM) concept. The overall
concept of the LCM, its individual philosophies and perspectives have been
distributed through publishing the guidebook, the manual, etc. The
individual components and methodologies in the LCM system, regarding
inspection, assessment, prediction, and planning of countermeasures andtheir timings, have been established by the authors’ previous research (eg.
Yokota et al., 2008 and Kato et al., 2009). In this paper, the fundamental
concept of the computer-based program to formulate the maintenance plan
for an open-type wharf based on the LCM system was discussed. The
computer-based program was developed to distribute the concept of LCM
system to port managers and engineers. The program was composed byuniting the individual components developed by the authors, such as
performance assessment and performance prediction based on the inspection,and countermeasures planning based on inspection and prediction.

2. OVERALLSYSTEM

CONCEPT

OF

LIFE-CYCLE

MANAGEMENT

Maintenance plan
Service period
Usage

Inspection

Input/Reference

DesignEnvironment

Assessment and Prediction
Database

Performance
Input/Reference・Inspection
・Prediction

Present

・Intervention

Time

Service life
Future plan

Countermeasure

Input/Reference

LCM system

Reduce LCC and realize rational maintenance

Figure 1: Procedure of life-cycle management.
Maintenance of port and harbor facilities is conducted according toprocedures that include accurate inspection of deformation (that is, damage
or deterioration) of structures, components or parts by timely andappropriate method, comprehensive evaluation of the results of inspections,and implementation of necessary countermeasures. In the implementationof these maintenance procedures, the following concept of LCM, as shownin Figure 1, represents an effective approach to rational and efficientmaintenance. The LCM system is composed of the following 4 main
components: 1) Inspection of present condition according to standardized
criteria, 2) Evaluation of residual performance, 3) Prediction of future384

New Technologies for Urban Safety of Mega Cities in Asia

performance degradation based on the result of inspections andcomprehensive evaluation considering the plans for future usage of facilities,
the remaining service period and life-cycle cost, and 4) Implementation of
appropriate countermeasures based on the results of the comprehensive
evaluation.

3. MAINTENANCE LEVEL AND MAINTENANCE LIMIT
3.1 Maintenance level
Table 1 lists the three kinds of maintenance levels indicating basic
concepts of how the performance will be guaranteed beyond the required
performance limit and the maintenance limit. Selection of the maintenancelevel as the basic maintenance policy is necessary when designing andformulating a maintenance plan of the facility. The performance of eachcomponent should satisfy their performance requirements during theirservice life according to the selected maintenance level. It is ideal to selectLevel 1 for all the components of a facility. However, considering theseverity of marine environmental conditions on the maintenance work, it
may not always be practical from the viewpoint of life-cycle cost. Therefore,
it becomes necessary to select the appropriately maintenance level of eachcomponent. It can be concluded that the maintenance level is the mostimportant concept to achieve the strategic maintenance based on the LCM
concept.

Level
Level 1

Level 2

Level 3

Table 1: Definition of maintenance level.
Definition
When predicting deterioration or deformation of components
in the design stage and the maintenance planning, noperformance degradation is expected. It is ensured that
deterioration and deformation affecting their performanceare minor during the design service period (that is, theperformance is always kept above the maintenance limit).
When predicting deterioration or deformation of components
in the design stage and the maintenance programming, theperformancedegradationiscontrolled.
Minor
countermeasures are repeatedly applied to keep the
performance above the maintenance limit.
When predicting deterioration or deformation of components
in the design stage and the maintenance programming, theperformancedegradationis
expected.
Major
countermeasures may be applied once or twice for
performance recovery. Application of preventive
countermeasures is expected to be difficult or uneconomical.

In an open-type wharf conforming to the Ministerial Ordinances on
the Technical Standards for Port and Harbour Facilities, the maintenancelevel of RC decks, steel pipe piles and corrosion protection treatments are
set as Level 1, 2 or 3, Level 1, and Level 1, 2 or 3, respectively. The reason
Development of Life Cycle Management System for Open-Type Wharf385

October 2009, Incheon, Korea

why the steel pipe pile is set as Level 1 is depending on the difficulty of its
implementation of inspection and countermeasures against corrosion. Oncecorrosion of steel pipe pile occurs, its structural performance, which is
directly related to the serviceability and safety of the entire structure,
becomes decreasing thereupon. Therefore, from the viewpoint of the safetyof structures and cost for countermeasures, applying the corrosion
protection treatment before corrosion occurring is considered to beappropriate.
3.2 Definition of maintenance limit
In the maintenance work based on the LCM concept, the performanceof each component in a facility shall be kept above the maintenance limit
and/or the performance limit according to the selected maintenance level.
However, definitions of each limit and performance degradation curves
have been shown in conceptual and non-quantitative image (eg. Ports andHarbours Bureau, 2007) to date.
Concerning the state of performance degradation of components, there
are a lot of research and inspection results of materials deterioration. In
addition to those, the trend of structural performance degradations ofreinforced concrete member and steel member has gradually been clarified
by recent ardent research. However, detailed inspections with advanced
expertise are generally required to evaluate the performance degradations
quantitatively. Therefore, at present, a visually inspected deterioration ordeformation in a component is judged as the deterioration grade instandardized criteria. Then, the deterioration grade is generally considered
to be an index of performance degradation of the component.
Table 2: Basic policy of judgment of deterioration grades.
Grade
Basic policy
Performance of component is seriously degraded.
dPerformance of component is degraded.
cPerformance of component is slightly degraded.
b
Performance of component is not degraded.
aIn this study, the deterioration grades, Grade d to a, according to thegeneral grading criteria in the Manual on Maintenance and Rehabilitation of
Port and Harbor Facilities were considered as an index of performancedegradation of components (Port and Airport Research Institute, 2007).
Table 2 lists the basic policy of judgment of each deterioration grade. In the
Manual, the grading criteria for each part and component of the structure areproposed by focusing on the visible deterioration and deformation, which
affects the performance of the component.
Aiming at making the theoretical relation between the visible
deterioration and the actual performance of component, the deterioration
grades and load carrying capacities of concrete members extracted from theexisting RC decks of open-type wharves were investigated (Kato et al.,386

New Technologies for Urban Safety of Mega Cities in Asia

2008). To compare the load carrying capacities of tested members withvarious structural details, the load carrying capacities were normalized bycorresponding calculated results based on the beam theory by using
designed values of material properties, shape and dimensions of themembers, and so on. Figure 2 shows the relationship between thedeterioration grades and load carrying capacities of concrete members. In
tested members judged as Grades c, b and a, there were large variations in
the load-carrying capacity. There existed the cases of which maximum load
ratios are smaller than 1.0 in Grades c, b, and a. From the safety evaluation
point of view, when deterioration grade was judged as Grades c, b and a, inother words, symptom of deterioration appeared on the surface of concrete
members, the load carrying capacity might become smaller than the design
expectations.

Maximum load
Exp. / Cal.

1.5

1.0

0.5

Exp. data

A verage

c1

b2

0.0

d0

a3

Deterioration Grade

Figure 2: Structural capacity vs. deterioration grade.
According to the definition of maintenance level listed in Table 1, it isnecessary to ensure that the deterioration affecting the performance of acomponent is minor during the designed service period in Level 1. Basedon the consequence of the relationship between the deterioration grades andstructural performance shown in Figure 2, it was considered to become theimportant constraint that the deterioration grade of the component of which
maintenance level was selected as Level 1 should be kept Grade dthroughout its service period without any countermeasures.
The structural performance of components is strongly related to theserviceability and the safety of a facility. In fact, the limitation of theperformance requirements, such as serviceability and the safety, of acomponent was considerably depended on its importance of structural
severity and the importance of a facility. However, considering thestructural performances of tested members and the rapid progress of steel
bar corrosion in concrete members judged as Grade a, it was considered to
become the important constraint that the deterioration grade of thecomponent of which maintenance level was selected as Level 3, at which
major countermeasure was scheduled to be applied before loss in required
performances, should be kept above Grade b during its service period.

Development of Life Cycle Management System for Open-Type Wharf387

October 2009, Incheon, Korea

For the components of which maintenance level was selected as Level2, countermeasures as the preventive maintenance are required to keep the
performance above the required performance limit. Considering theconstraints for Levels 1 and 3 in addition to the above condition, theimportant constraint of the component for Level 2 was considered to be kept
the performance above Grade b or Grade c. Whether the maintenance limit
was Grade b or Grade c should depend on the importance of the components
and the easiness of its countermeasure.
In this study, the maintenance limit of performance of a component
for each selected maintenance level was defined as shown in Figure 3. Thisdefinition was applied to all the components in open-type wharf in thedeveloped computer-based program. Because these limits were proposed
based on the test results of structural performance degradation of concrete
members, it is not considered appropriate to apply these limits to other typesof members than concrete members such as steel pipe piles, corrosion
protective treatments and so on. Definition of the maintenance and required
performance limits of each component should be improved by accumulating
further inspection data and experiments.
Maintenance level 1dcMaintenance level 2ddMaintenance limit

c

c

b

b

a

a

Maintenance level 3

Maintenance limitbaMaintenance limit(= Required performance limit)

Service life

Service life

Service life

Figure 3: Definition of maintenance limit for each maintenance level.

4. SUMMARY OF THE COMPUTER-BASED PROGRAM TOFORMULATE A MAINTENANCE PLAN
Figure 4 shows the flow of the computer-based program to formulate amaintenance plan. The program is composed of 4 main components in the
LCM system shown in Figure 1.
Program users can formulate the comprehensive maintenance plan withconsidering the life-cycle cost and the remaining service life of the target
facility. Maintenance levels of each component shown in Figure 3 are set atthe first stage of the program. The maintenance plan formulations of eachcomponent are automatically controlled for each selected maintenance levelin the programs. In addition to those, the items and timings of theinspection for each component during their service life can be planned in the
program. Because the open-type wharf was located in the severe
environmental conditions affected by wave, splash, tidal changes and so on,

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New Technologies for Urban Safety of Mega Cities in Asia

the implementation of inspections generally requires the special techniques,
such as shipboard inspections, inspections by divers, inspections fromplatforms etc. Therefore, the cost related to the inspections was considered
to have an influence on the life-cycle cost of the open-type wharf comparedwith that of the land structures.
In this study, two kinds of programs, for newly designed open-type wharvesand for existing ones, were developed, while the bases of overall systemwere the same. For newly constructed open-type wharves, the applicationof the performance based design and the formulation of the maintenanceplan consequently bring the ensured prevention of performance degradation
during the service period. However, for existing ones, only implementationof the maintenance plan based on the result of inspections can supplement
non-ensured performances of structures in the design stage.
In the program for existing open-type wharves, the deterioration prediction
using the result of inspection was available. Moreover, the probabilistic
prediction considering the dispersion of the deterioration grades in theactual conditions can be carried out based on the Markov chain model(Yokota et al., 2006). The example of the maintenance plan for an existing
open-type wharf formulated by the developed computer-based program wasdescribed in the following chapter.
Start
Input structural information
Setting Maintenance level of components
Setting Maintenance limit of components

For New
For Existing

Input results of inspections

RC deck

Steel pipe pile

Deterioration prediction of RC slab and beam
Selection of countermeasures
Calculation of cost relating to countermeasures

Planning of Inspection

Deterioration prediction and/or setting of designed
service life of corrosion protection treatment

Selection of countermeasures
Calculation of cost relating to countermeasures

Proposal of design
condition

Planning of Inspection

Calculation of LCC

Calculation of LCC

Integration
Decision of whole maintenance plan

Figure 4: Flow of the computer-based program to formulate a maintenanceplan.

5. EXAMPLE OF MAINTENANCE PLAN
The target structure shown in Figure 5 was an open-type wharf which had
been in service since 1983. Its designed service period was 50 years. In
1995, the cathodic protection was applied to the parts of steel pipe piles inthe submerged zone. The maintenance levels and the maintenance limits ofDevelopment of Life Cycle Management System for Open-Type Wharf389

October 2009, Incheon, Korea

decks and the corrosion protection treatments were set at Level 2 and Gradeb. The maintenance level of steel pipe pile was set at Level 1. Table 3 lists
the deterioration grades of each component judged by visual inspection
carried out in 2008. Because almost all of mortar lining for corrosion
protection and RC beams already became Grade b, the target structure wasconsidered to require the application of countermeasures as soon as possible.
However, measured protective potential of steel pipe piles at the submergedzone were below -800 mV vs. Ag/AgCl electrode; therefore, the cathodic
protection system was still effective.

Figure 5: Cross-sectional view of target structure.
Table 3: Deterioration grades of each component.
Deterioration grades and its ratio

Component
RC deck

Slab
Beam

Steel pipe pile(at tidal zone)

Mortar lining

d

c

b

a

0.0 m20.0 %18.9 m2
5.1 %0 pile0.0 %253.2 m2
66.4 %
76.0 m2
20.6 %
5 piles
20.8 %

108.6 m2
28.5 %
205.9 m2
55.7 %
15 piles62.5 %

19.6 m2
5.1 %
68.9 m2
18.6 %
4 piles
16.7 %

Comparing the repair costs for the RC deck and the mortar lining, thecathodic protection to RC deck and the petrolatum lining to the parts of pilesin the tidal zone were recommended to apply as the countermeasuresconsidering the remaining service life of the target structure. In addition tothis, because the cathodic protection system at the submerged zone waspredicted to be effective until 2014 according to the prediction result of theconsumption amount of galvanic anodes, the galvanic anode of which
designed service duration was 20 years was scheduled to re-install to all
piles in 2014.
Table 4 lists the items and timing of inspections. Visual and detailed
inspections were scheduled to carry out every 3 years and 10 years
respectively. The shipboard inspections and inspections implemented bydivers were classified as the detailed inspection items. The amounts and thenumber of parts of the inspections were decided according to the Guidebook

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New Technologies for Urban Safety of Mega Cities in Asia

for Preparation of Port and Harbor Facility Maintenance Programs (Port andHarbours Bureau, 2007).
Considering the schedules and each cost of the countermeasures andinspections, the LCC in the remaining service life of the target structure wascalculated as shown in Figure 6.
Table 4: Items and amounts of inspections.
Component

Inspection item

RC deck

Visual inspection
Detailed visual inspection
Measurementofchlorideion
concentration in concrete
NDT for estimating cover depth
NDT for corrosion of steel bar
Survey (position and level)
Visual inspection
Detailed visual inspection
Detailed visual inspection
Measurement of protective potential
Measurement of consumption amount ofgalvanic anode
Measurement of galvanic anode current

Steel pipe piles at
the tidal zone
Steel pipe piles atthesubmerged
zone

Visualinspection
100 %*
No
No

Detailed
inspection
100 %*
20 %*5 samples

No
No
Yes
100 %*
NoNo
20 points
No

5 points
5 points
No
No
50 %*
100 %*
20 points
3 points

No

1 point* Ratio to the total surface area of components (%)

Inspection of Piles

1800
1600

Inspection of RC deck

Total cost

1400
1200

Cathodic protection at
Piles

1000
800

Protective coating at
Piles

600
400

Cathodic protection at
Beams

200
0
2008
1

2013
6

2018
11

2023
16

2028
21

Cathodic protection at
Slabs

Figure 6: LCC of the target structure.

6. CONCLUDING REMARKSIn this paper, the fundamental concept of the computer-based program toformulate a maintenance plan for an open-type wharf was discussed. Someof evaluation and prediction methods in the proposed program, such as thedefinition of the maintenance limit and required limit of each component,
should be improved by accumulating further inspection data andexperiments. However, the authors expect that rational and effective
maintenance would be realized by the results of this research andsubsequently the life-cycle cost reduction and performance maximization
Development of Life Cycle Management System for Open-Type Wharf391

October 2009, Incheon, Korea

could be attained. The part of this present research has been financially
supported by the JSPS Grant-in-Aid for Scientific Research (B) No.
20360195.

REFERENCES
Kato, E., Yokota, H., Iwanami, M., Akira, Y. and Kawabata, Y., 2008.
Simplified assessment for structural performance of deteriorated RC deck.
Proceedings of 2nd International Workshop on Life Cycle Management of
Coastal Concrete Structures, Hangzhou, China, pp.75-80.
Kato, E., Iwanami, M. and Yokota, H., 2009. Development of Life Cycle
Management System for Open-type Wharf, Report of the Port and Airport
Research Institute, Vol. 48, No.2, pp.3-35.
Port and Airport Research Institute, 2007. Manual on maintenance andrehabilitation of port and harbour facilities, Coastal Development Instituteof Technology. (in Japanese)
Port and Harbours Bureau, 2007. The Guidebook for Preparation of Portand Harbor Facility Maintenance Plan, Service Centre of Port
Engeering.(in Japanese)
Yokota, H., Komure, K. and Takahashi, H., 2006. Lifecycle Management ofConcrete Deck by Markov Model, Lifetime Engineering of Civil
Infrastructure, pp.137-149.
Yokota, H., Iwanami, M., Yamaji, T. and Kato, E., 2008. Life-Cycle
Management of Concrete Structures in Coastal Areas. Proceedings of 2ndInternational Workshop on Life Cycle Management of Coastal Concrete
Structures, Hangzhou, China, pp.53-58.

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New Technologies for Urban Safety of Mega Cities in Asia

URBAN DISASTER AND EMERGENCY
EXERCISE IN REAL TIME 3D SOCIAL
VIRTUAL ENVIRONMENTS
ALI ASGARY
Emergency Management, School of Administrative Studies, Faculty of
Liberal Arts and Professional Studies, York University, Canada
asgary@yorku.ca

ABSTRACTThis review-case study paper introduces real time 3D social virtualenvironment and their educational and practical applications in urban
disaster and emergency exercises. Second life (http://secondlife.com/) is
one of the most popular 3D virtual world platforms in use today, with anemphasis on social interaction. Conducting real world large urban disaster
exercises are very costly. Real time 3D social virtual environments provide
virtual environment in which disaster simulations and exercises could be
integrated with social interactions and communications which are essential
elements for a successful exercise This paper describe some urban disasterand emergency simulation and exercise cases from Second Life, including
the first International Virtual Swine Flue Exercise conducted in the York
University Virtual Emergency Operations Centre in Second Life in May
2009 (supported by the International Association of emergency ManagersIAEM). The goal is to show how real time 3D virtual environments could be
used for disaster simulations and exercises that need stakeholders’ social
interactions. The potentials applications of Second Life in urban disaster
simulation and exercise are then discussed, as well as some issues andchallenges related to the use of virtual worlds.

1. INTRODUCTION
Simulations and exercises facilitate improved disaster and emergency
management. They improve emergency planning, coordination andcommunication and have many other educational and training benefits suchas the development of a shared or common language and enabling similar
thinking regarding the nature of the emergency (Galley et al., 2004).
Simulations and exercises provide a common understanding of the ensuing
issues and their prioritization, identification of available resources and theirdeployment, and the articulation of a system to communicate withorganizations in an effort to produce a coordinated response. Increased
knowledge of the risks and impacts of a threat through simulation andexercise improves awareness of the need for effective planning and the needand usefulness of training. Such knowledge also provides a realistic
appraisal of the problems related to an event, allowing responders to act in
an informed manner rather than without prior ideas and thoughts.

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October 2009, Incheon, Korea

Furthermore, the use of simulation and exercise as a means of establishingrealistic expectations serves to reduce emergency managers’ stresses (Boinet al., 2004). This rationale argues for the importance of providing realistic
training through the use of simulations and exercises. Using disaster
simulations in an active engagement, realistic frameworks and sharedlearning is one way of incorporating all of the education components andaid disaster and emergency managers in dealing with disaster events(Taraban, Box, Myers, Pollard & Bowen, 2007; Bluestone, 2007; Hake,
1998; Micheal, 2006). While simulations cannot quite replay actual crises,
they are the closest form of exposure many participants might have to adisaster prior to an actual event, thereby providing an opportunity to learn
and practice in a calm, controlled environment.
Computer base simulations are becoming an important element ofdisaster simulation and exercise planning (Smith, Dowell & OrtegaLafuente, 1999). Conventional computer-based simulations allow
participants to interact in a dynamic disaster domain model through the useof video, audio and/or computer graphics. Complex systems allow
interaction with multiple users within the scenario enabling the process ofcoordination. Today a new component has been added to the computer
based simulation; that of the real time virtual on line environments. This is arelatively new and emerging learning environment. This paper explains
how on line virtual environments such as second life can be used in disaster
simulation and emergency exercises. The remaining parts of re organized asfollow: Section 2 provides some backgrounds on disaster simulations andthe virtual world. Section three discusses the use of Second Life virtualenvironment in disaster simulations and emergency exercise. Section four
reviews the use of Second Life by the author at York University. Section
five concludes the paper

2. DISASTER SIMULATIONS AND EMERGENCY EXERCISESAND THE VIRTUAL WORLD
2.1. Types of Disaster Simulations and Emergency Exercises
Disaster simulations and emergency exercises are common tools usedthroughout the world to evaluate and improve responses during an event andthey range in type, scope and the number of players involved. All
simulations and exercises share the common goal of identifying areas
requiring improvement, thereby necessitating an evaluation of thesimulation or exercise (Green et al., 2003).
Disaster simulations and emergency exercises are developed to allow
individuals to experience uncertain and unknown conditions and provide an
opportunity for organizations to work collectively during stressful andvaried contexts. The benefits of exercises and lessons learned are variable(Lonka & Wybo, 2005). Several gains can be realized through the use of
emergency simulations, including allowing participants to increase theirfamiliarity and test all aspects of emergency management which otherwise
can only be experienced through in vivo exposure (Boin et al., 2004).

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Exercises are invaluable in providing information regarding emergency
management related to a specific incident (Lonka & Wybo, 2005).
Simulations provide an easy method to obtain lessons learned, identificationof issues and an opportunity for multi-agency communications. Often
participants are unaware of the politics involved in crisis decision-making;therefore simulations give participants insight into how and why somestrategies are employed and why some are not, and present participants witha greater understanding of the process and its limitations (Hermann, 1997).
While real emergencies do not allow for failure, an exercise does and it
provides an opportunity to try again. In addition, systematic andspontaneous feedback following the simulation is important to allow
participants an opportunity to evaluate their own behavior, the rationale fordecisions made and identify problems specific to their organization
especially when used for training, teaching and planning purposes (Kleiboer,1997). Successful exercises depend on two main variables: similarity to realcircumstances and motivation of the players (Lonka and Wybo, 2005).
Simulations are tools for learning and a variety of types are utilized.
Traditional approaches include “table-top” discussion based exercises, drills,
functional and full scale exercises. Table-top exercises provide disastermanagers an occasion to practice the activation of the response plan in acontrolled, low stress environment and are often based on policy issues witha focus on processes (Canton, 2007; Coppola, 2007). Rather than having
participants perform their functions, a detailed discussion occurs andproblems and weakness are identified and dealt with. Table-top exercises
are effective because they eliminate stress and time limitations often foundduring an event. Discussions also identify poor planning assumptions andprovide a platform to clarify misunderstandings. These exercises areversatile in terms of length and cost. According to Smith et al. (1999) the
learning takes place through the experience of discussion. While discussion
based exercises lack the realism of other exercise types, they offer several
instructive strengths including face to face discussion, exposure to eachothers’ technical language, priorities, interpretations, organizational needs,
favored resolutions and assumptions (Smith et al., 1999).
Drills are supervised, controlled exercises during which a single
emergency operation is tested. Drills are often cost effective, require lessplanning time and focus largely on one issue. Functional exercises test
disaster manager capabilities by simulating an event that requires a response.
This exercise type tests a variety of related activities that collectively
accomplish an overall response (Canton, 2007; Coppola, 2007). Functional
exercises add the element of time, therefore introducing stress into thescenario. Participants must respond to the request as opposed to discussion
only, adding to the realism of the exercise. Functional exercises require amoderate amount of resources and several months of planning. Full-scale
exercises are complex, scenario based, and attempt to simulate a realdisaster, using actors and props. These exercises test all aspects of a plan forfunctionality, accuracy and effectiveness. This type of simulation requires
many resources including the participation of all functional roles as outlinedin the emergency operations plan, the activation of multiple response levels
and tests the functionality of the plan. The exercise occurs in real time
utilizing all procedures and equipment required in a real event.
Urban Disaster and Emergency Exercise in Real Time 3D Social Virtual Environments395

October 2009, Incheon, Korea

Disadvantages of this type of exercise are the vast cost and planning timerequired. This method is the best for testing jurisdictional emergency
management capacity.
2.2. Disaster Simulations and Exercises in the Virtual World of Second
Life
Multi-user virtual environments offer several benefits including
providing a more leisurely approach to learning, interacting with digital
objects, representing themselves through an avatar, communicating withother participants while engaging in collaborative learning activities andtaking part in modeling and mentoring experiences similar to those in realworld contexts.
Training in the virtual environment can be more cost effective andrealistic in ways that staged disasters cannot. For example, in the simulated
environment, if first responders fail to put on their safety vest or reflective
jacket when approaching the scene of an accident, their avatar may be hit by
a car a negative reinforcement that could not occur in a real-life training
exercise (Raths, 2008). Virtual disaster simulations provides emergency
responders from all disciplines the opportunity to train together in real time
for the purpose of learning the latest best practices in incident scene safety,
coordination, and quick clearance of emergency events (The Center for
Advanced Transportation Technology, 2008).
Second Life (SL) is a free online virtual world imagined and createdby its residents (www.secondlife.com). It is a “digital world filled withpeople, entertainment, experiences and opportunity”. It was publicly
released in 2003 by Linden Labs based out of California (Linden ResearchInc., 2009). Within SL environments, participants can share slides, audio andvideo, engaging in discussions, presentations, group projects, and explorations.
Second Life is currently one of the largest virtual worlds operating (Williams& Hudson, 2008). At any time there may be over 65,000 users logged in andexploring different aspects of the world. Once in-world, users are able to doa variety of everyday things such as strolling through the park, shopping at
the mall or going for a drive down the coast (Linden Research Inc., 2009).
Second life is a completely user-generated content, is relatively easy-to-use
and build in which users own the intellectual property for their creations.
Virtual disaster simulations and exercises in places like Second Life
have attracted many people because they are cost- and time-effective (Wyld,2009). Since its opening public and private organizations, colleges anduniversities and independent researchers and developers have used second
life for various disaster and emergency simulations and exercises. One of
the reasons that SL can be used for emergency training and exercises is thatit allows “for rich sensory immersive experiences, authentic contexts andactivities for experiential learning, simulation and role-play (Kay,
Educational uses of second life, 2009). These are the key ingredients for a
successful emergency simulation and exercise. Further, SL notes that theopportunities for collaboration and co-operation are possible in virtualworlds like SL but are not as easily experienced using other platforms.
Using SL, disaster and emergency trainers and educators can radically

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expand the problems that participants are able to address. This increase
happens in two areas. The first is with problems that are infeasible toexperience due to a lack of resources and second is with problems that are
impossible to experience because of the limits of the physical world (Mason,2007).
Second life has been used as a platform for disaster and emergency
related training and education by universities, research institutes, public andgovernment agencies and the private sector. At the University of
Maryland’s Center for Advanced Transportation Technology, researchers
have been developing a virtual-world training exercise encompassing manydifferent traffic scenarios, from minor accidents to major incidents for use
by emergency responders in the I-95 Corridor Coalition. These simulations
can now include hundreds of participants playing out their real-world
response functions in the virtual environment (Lynch, 2008).
USgovernment organizations such as National Oceanic and Atmospheric
Administration (NOAA), CDS, and DHS have created their own site insecond life and provide various hazard and emergency management
education and training. Usefulness of virtual environments such as second
life has attracted private companies as well. SRA International Inc. is atechnology provider with presence on Second Life. It provides services toorganizations in the national security, government, health care and publichealth markets by designing, developing and integrating systems which,among other things, help facilitate efficient responses to disasters.

3. YORK UNIVERSITY’S VIRTUAL EMERGENCY
MANAGEMENT LAB IN SECOND LIFEAt York University in Toronto, Canada, Ali Asgary (the Author), uses
Second Life for distance education, research and professional exercises.
Because of the dynamic nature of the subject matter, moving from a printbased to a 3D environment offers a more realistic visual sense of thetemporal spatial dimensions of a disaster scene, which distinguishes it fromthe usual discussion-based simulations that occur in class. It would beprohibitatively expensive and logistically too complex to arrange real-life
disaster simulations especially for university courses, so the SL environment
provides an opportunity for students normally outside the scope of what canbe taught in a structured learning environment. By utilizing the real-time
audio function, students, who are assigned roles for the exercise such as
mayor, fire chief, paramedic, etc., are able to coordinate their activities tomanage the different aspects of a given disaster from their multiple
perspectives by talking to each other in real time. The disaster simulation is
set in the York University Virtual Disaster and Emergency (DEM) Lab in
Second Life on a private island. The lab includes a Virtual Emergency
Operations Centre (VEOC), a Media and Training Room, and a Virtual
Disaster and Emergency Management Exhibition Hall, not yet completed, inwhich emergency management-related technology products will beshowcased and tested. It is this virtual scenario that is used for the live tabletop exercises.

Urban Disaster and Emergency Exercise in Real Time 3D Social Virtual Environments397

October 2009, Incheon, Korea

3.1

The Trillium Emergency Exercises

Two table top emergency management exercises have been conductedby students taking an emergency management course at York University.
The first exercise was conducted by students who took the course insummer 2008 as an internet course and the second exercise was conductedby students who took the course in campus during Winter 2009. While thefirst exercise was very much a virtual table top exercise without any
simulation of the disaster scene, the second exercise involved somesimulations of the actual disaster event. The emergency scenario wasadopted from a real world emergency exercise developed by the Emergency
Management Ontario as a community training tool. Both exercises took
place in the fictional industrial town of Trillium, a mid-sized region with apopulation of approximately 250,000 to 300,000 inhabitants located in
United County. During the summer and in the middle of the business week
at approximately 8:37AM, a single explosion occurs at the Trillium
Chemical Factory that is preceded by a series of secondary blasts that resultin numerous deaths and injuries.
Students played a different role as a member of the Emergency
Operations Centre (EOC), such as the mayor, community emergency
management coordinator, fire chief, police chief and medical officer ofhealth etc. In the winter in-campus emergency management course,
students were offered three distinct options for the final term project. One ofthese options was a virtual emergency table top exercise that was to beorchestrated online in the Second Life virtual environment. In the eyes ofthe students affiliated with this project, this option proved to be one of the
scarcest opportunities to be granted at the undergraduate level. After all, thesheer thought of utilizing innovative virtual technology to replicate actions,
meetings, and exercises stemming from an emergency scenario were likely
to be the closest interactive experience to a real life emergency.

Figure 1: A scene from the virtual disaster and emergency
management exercise conducted by on line students in Second Life in July
2008
The virtual tabletop exercises were conducted fully online. In orderfor the virtual tabletop exercise to be implemented as smoothly as possible

398

New Technologies for Urban Safety of Mega Cities in Asia

at various transition points, the exercise team had devoted much time inrevising the script, organizing joint meetings after class and online, andfurther rehearsing several times prior to the actual presentation. The final
exercise script was made in compliance with the scene that we intended tocreate, as well as the feedback from members after each rehearsal. Apartfrom each character’s line, a detailed description of character placements foreach scene was included in the script to ensure that each member would
know exactly where to be at which scene. A majority of the meetings
conducted were held online in Second Life in order to accommodate
individual schedules and to help familiarize all members with the Second
Life environment.
All students who participated in these exercises provided their
feedbacks and evaluations of the exercise. Distance learning tends to be
impersonal, but the Second Life online environment provided an
opportunity for creative collaboration and real-time interaction between
students that would have otherwise never met. The students seemed toenjoy and learned very much from the virtual experience. They found itvery interesting, engaging and fun and a very creative approach as tosimulating a table-top exercise. Students in distance education course foundit interesting to be able to hear everyone’s voice and communicate withthem through Second Life. Students believed that Second Life has thecapability of incorporating a class-like atmosphere in an online course, onethat is less monotonous and allows for more interactions.
Students believed that the scenario provided a very useful learning
tool for students fresh to the field of disaster and emergency management.
And they highly recommended this type of project for future introductory
courses to disaster and emergency management. The Second Life exercise
put in perspective how serious and fatal a real disaster can be. This exercise
was useful in learning how a community must work as a team and utilize allavailable resources to overcome such a catastrophic event. Through thisproject and practice, students learned the process of emergency response
vividly and gained a better understanding of the whole scenario. It helped
them understand the duties of an emergency response team. They also
learned that effective communication in emergency management isimportant. As for Second Life, they mentioned that it is a good way to dosome table-top exercises in emergency management.
Many students highlighted that it was very interesting for them toconduct a group project through Second Life and were able to act out scenesthat appear in real life. The learning experience of this virtual exercise
helped a lot in terms of understanding the importance of working together
during the planning process of an emergency and that such processes cannot
be done by one person. Overall, this exercise was useful as it allowed thosethat are interested in the emergency management field to have a glimpse andsome sort of “hands-on” experience with the possible happenings each role
would have to encounter.
Some of the students mentioned that the Second Life experience wasunlike any other they had encountered at York University. To engage indistance learning of this caliber and still listen and contribute in real time asif we were in a classroom is something unheard of in Internet-assisted
learning. The program gave us (the group members) the flexibility to sit at
Urban Disaster and Emergency Exercise in Real Time 3D Social Virtual Environments399

October 2009, Incheon, Korea

home and plug into group meetings and take part in voice-to-voice
discussions over our headsets. The Second Life table top presented thestandard operations of an Emergency Operations Centre while adding aheavy visual component in the design of the aptly named ‘York DEM
Island’. According to the participant this option should be available forstudents taking part in ADMS 3700 for years to come”.
According to the team members the Second Life program is a great
way of learning emergency management procedures and guidelines as wellas providing distant assistance. In terms of usefulness this exercise does
benefit students greatly in learning and applying the knowledge of in class
information to a disaster scenario. The table top exercise in Second Life isan excellent tool to expose students to the process of responding to an
emergency. According to the students this second life virtual exercise was a
success despite a few technical problems. The concept of the Second Life
program for emergency management exercises is very useful; however the
program itself still has many technical problems to be improved. Althoughstudents ventured into the concept of Second Life with no prior knowledge
in both the fundamentals of emergency management and in virtualtechnology software, they came out with a cohesive, well-executed disaster
scenario. Technical issues aside, the online table top provided students witha real grasp on the operation procedures which take place within an EOC.
The usefulness of this specific format is highlighted in its ability to allow for
flexible meeting times and let students think outside of the classroom. For
most of the students this was the first time that they were using Second Life.
It was an engaging and fun experience for students and they learned a lot
from the project on how emergency situations are actually handled and what
happens behind the scenes from the moment an emergency is detected until
the end.

Figure 2: Students participated in the Trillium table top exercise in
Second Life in May 2009

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New Technologies for Urban Safety of Mega Cities in Asia

3.2. The First International Virtual Emergency Exercise
The first international virtual emergency exercise was held in the York
University Virtual Emergency Management Lab in Second Life on May 5
and May 7, 2009. This event was organized by the Emergency Management
Program at York University, Toronto, Canada, in collaboration with theInternational Association of Emergency Managers (IAEM). More than 50
participants and observers, mostly the IAEM members who received the callfor participants through the IAEM discussion list, were from the USA,
Canada, United Kingdom, Spain, Turkey, Australia and the Netherlands.
They came together in real time and participated in these exercises. The
exercise scenario was an H1N1 Influenza (swine flu) pandemic developed
based on a Rand Corporation pandemic exercise impacting a hypotheticalcity
between
April
to
July
2009
(www.rand.org/pubs/technical_reports/TR319/). This scenario was chosen
mainly because of the ongoing worldwide concerns regarding the swine flu.
The exercise goals were: 1) to examine the usefulness, challenges and issues
of using the Second Life virtual environment as a platform for conducting
emergency exercises from emergency professionals’ perspectives. 2) To
understand and exercise the key preparedness and response elements of aswine flu emergency (surveillance and epidemiology; command, control andcommunications; risk communication; surge capacity; disease prevention
and control) at a typical local government setting.
As with a real world emergency exercise, these virtual tabletop
exercises were held in the York University virtual EOC conference room
(snapshots of the May 5 exercise are temporarily available atwww.yorku.ca/cst/zDEMmovies-temp/). These exercises simulated what
would happen in a face-to-face tabletop exercise. Considering that many
participants were first-time Second Life users but still were able to actively
participate in the virtual exercise shows that the learning curve is not amajor issue when it comes to using Second Life for such virtual exercises.
Participants must have the basic required hardware (a recent computer witha good graphic card and a headset) and software (Second Life browser
available free after registering at www.secondlife.com).

Urban Disaster and Emergency Exercise in Real Time 3D Social Virtual Environments

401

October 2009, Incheon, Korea

Figure 3: The first International Emergency Management Exercise in
Second Life conducted on May 2009
At the end of each exercise, a polling station was used to evaluate theexercise. Overall participants’ responses to the survey questions showed thatthese virtual exercises were successful in achieving their initial goals.
Respondents found the exercise to be “very impressive, fun and interesting,”“very useful” and a “good and new experience”. Some of the participants
were impressed with how the conversation developed over the course of theexercise and with the visualization and simulation capacities of the virtualworld for conducting various emergency management exercises. Most
participants mentioned that virtual environments such as this seem to be a
viable distributed environment for tabletop exercises, especially when it isdifficult or costly to bring people together in one physical place.

4. CONCLUSION
Overall, using Second Life virtual environment seems to be a feasible andan excellent learning experience for disaster and emergency simulation andexercises. Through experimentation and learning how to use SL, thesimulation and exercise team members can see potentials for virtual
simulations. It is a safe learning environment and a cost effective way of
exercising emergency plans once the scenario is set up. As with othercomplex software systems, the full benefit of SL can only be realized withinformed and expert manipulation. The end product of the simulation could
be used for exercise purposes as described in the research literature. The
benefits of using SL are greater than the drawbacks. The uses of Second
Life in the practice of emergency management should be further explored,with expert guidance.

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The Second Life emergency table top exercise has proven to be an
innovative solution to the standardized exercises currently undertaken. The
ability to create life like avatars and base functions in a virtual Emergency
Operations Centre adds depth and a new level of realism that simply can not
be replicated within the confines of a conference or class room. The concept
itself of bridging virtual technology with emergency management concepts
allows the user(s) to interact, listen, and showcase their knowledge in theoperations cycle of a disaster.
ACKNOWLEDGEMENT
The author would like to thank the York university students and IAEM
members who participated in these exercises and provided their feedbacks
and learning experiences. This work could not be accomplished without
their interest, enthusiasm and support.

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Bluestone, C., 2007. Infusing active learning into the research methods unit.
College Teaching , 55, 91 - 95.
Boin, A., Kofman-Bos, C., & Overdijk, W., 2004. Crisis
simulations:exploring tomorrow's vulnerabilities and threats. Simulation and
Gaming 35, 378 - 393.
Canton, L., 2007. Emergency management concepts and strategies for
effective programs. John Wiley & Sons, New Jersey.
Coppola, D., 2007. Introduction to international disaster management.
Elsevier, New York:.
Galley, I., Leonard, G., Johnston, D., Balm, R., & Paton, D., 2004. The
Ruspehu lahar emergency response plan development process: An analysis.
The Australasian Journal of Disaster and Trauma Studies 1.
Green, G., Modi, S., Lunney, K., & Thomas, T., 2003. Generic evaluation
methods for disaster drills in developing countries. Annals of Emergency
Medicine 41, 689 - 699.
Hake, R., 1998. Interactive-engagement versus traditional methods: A sixthousand-student survey of mechanics test data for introductory physics
courses. American Journal of Physics 66, 64 - 74.
Hargis, J. P., 2008. A second life for distance learning. Retrieved May 25,
2009, from Turkish Online Journal of Distance Learning:
http://tojde.anadolu.edu.tr/tojde30/index.htm
Hermann, M., 1997. In conclusion: the multiple pay-offs of crisis
simulations. Journal of Contingencies and Crisis Management 4, 241 - 243.
Kay, J., 2009. Educational uses of second life. Retrieved May 29, 2009,
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Education:
http://sleducation.wikispaces.com/educationaluses
Kleiboer, M., 1997. Simulation methodology for crisis management support.
Journal of Contingencies and Crisis Management 4, 198 - 206.
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Kolb, D., 1984. Experiential learning: experience as a source of learningand development. Prentice Hall, Englewood Cliffs.
Linden Research Inc., 2009. What is second life? Retrieved May 25, 2009,
from Second Life: http://secondlife.com/whatis/
Lonka, H., & Wybo, J., 2005. Sharing of experiences: a method to improve
usefulness of emergency exercises. International Journal of Emergency
Management 2, 189 - 202.
Mason, H., 2007. Experiential education in second life. Second Life
Education Workshop 2007 (pp. 14 - 18). Chicago: www.simteach.com.
Micheal, J., 2006. Where's the evidence that active learning works?
Advances in Physiology Education 30, 159 - 167.
Mitchell, J., 1997. Can hazard risk be communicated through a virtual
experience? Disasters 21, 258 - 266.
Smith, W., Dowell, J., & Ortega-Lafuente, M., 1999. Designing paper
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Taraban, R., Box, C., Myers, R., Pollard, R., & Bowen, C., 2007. Effects ofactive-learning experiences on achievement, attitudes and behaviours inhigh school biology. Journal of Research in Science Teaching 44, 960 - 979.
Williams, A., & Hudson, M., 2008. Reflections in wonderland. SCONULfocus 43, 19 - 21.
Wyld, D., 2009. Government in 3D: How Public Leaders Can Draw on
Virtual Worlds’, IBM.

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New Technologies for Urban Safety of Mega Cities in Asia

QUANTITATIVE EVALUATION OF ESCAPE
SAFETY CONSIDERING EXTENSION OF
ESCAPE TIME BY ESCAPE DISTANCEAND ESCAPE BARRIERGUNSIK JEONG and YOUNGCHULL AHN
Pusan National University, Geumjeong-gu, Busan 609-735, Korea
gunsik72@hanmail.net

ABSTRACT
Escape distance and escape barrier are main elements for thequantitative evaluation of escape safety and they have been analyzed andproved by theoretically for their generalization and adaptation using asimple and a real plane model in previous studies. However, we should
consider that there are many complex barriers in the escaping route, andthe actual conditions must be considered in the study of escape safety. So
the quantitative analysis on the effects of each barrier and escapeconditions to the escape safety is necessary.
In this study, the quantified function which can predict various escapebarriers in the escaping route is derived by theoretical analysis of escapebarriers and conditions. The derived function is substituted for theevaluation tool, which is suggested in the previous study for the evaluationof escape safety, and evaluated with the simultaneous consideration of theescape conditions and the barriers. The results can be simulated in a
hospital that has complex escape routes and various barriers, then it isanticipated more exact and actual escape analysis model can be acquired.

1. INTRODUCTION
Expansion of urban area and overpopulation cause large, complex and highrise buildings, however, it is more difficult to build a plan for preventing
disasters such as a fire, an earthquake, a storm, a flood and a terror. So more
tight regulations than the building law and the Fire Services Act are needed.
Researches about the improvement of safety of a city and a building havebeen performed in the various field and also there are many fruitful results.
But the results are not sufficient and there needs more improvements.
If we can recognize quantitatively the degree of hindrance of the leaved
things and establishments in the escaping way which can reduce effective
width of the way, and obstacles such as doors and stairs, then it can beconsidered during the design process and contribute to plan of urban andarchitectural design. Also it can affect custom of users and administrators todevelop safety and performance of disaster prevention.

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In this study, obstacles which are located on the evacuation way are
investigated and analyzed according to the evacuation conditions such as
power of locomotion and moving pattern, And a function which canquantify the degradation of evacuation safety due to the obstacles isderived. Also the validity of the function is verified by comparing with theprevious works.
2. PREVIOUS WORKS AND THEORIES
2.1 Previous works
There are several researches about the evaluation method of
evacuation safety. Choi, Jae-Pil(2006) suggested an evaluation model for
special space using a concept of evacuation expenses by visibility graphanalysis, and analyzed with a case of actual building. Oh Jung Woo(2007)
suggested a network model of indoor area using a network theory andstudied possibility of automatic search of evacuation path. Kim, JongHun(2007) researched evacuation of multiplex cinema using a fire
simulation and evacuation simulation based on the CO concentration andevacuation time.
Berlin evaluated escape potential, Mikio TAKAGI(1991) suggested
exponential constants for network analysis and adapted to the analysis ofunderground passage, Yoshitsugu AOKI(2001) suggested modification ofvalue of weight of network using neural network, Shigeyuki OKADA(2003)
adapted a concept of degree of risk to network analysis, and Kouji
SHIDA(2002) considered behavior ability of a people to the evaluation ofevacuation safety.
2.2 A model for change of reliability due to the escape distanceand obstacles
2.2.1 Evacuation safety and reliability
A "reliability" is used as an index of evacuation safety and it isdefined as "a probability which can insure the safe evacuation way from theinitial evacuation place to the final safe place in disaster circumstances."
However, the reliability has a meaning of relative comparison because theresults are not reflected any experimental or simulated analysis. That is, it
can not be believed that the safety is double when the reliability is double.
However, if we establish a database based on the actual in the near future.
2.2.2 Reliability of a link and a network
Fig. 1 shows an example of network graph for the connection from
evacuation starting node S to finishing node G, G1 and G2.
The passing through probability of each connection is represented as"link reliability", and "network reliability" represents combined reliability
which is considered from all the link reliability.

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New Technologies for Urban Safety of Mega Cities in Asia

The network reliability in a network model can be calculated,
In case of series connection (Fig. 1 (a))
Rij = ri × r j(1)
In case of parallel connection (Fig. 1 (b))
Rij = 1 − (1 − ri )(1 − r j )(2)

Rij： Combined reliability(network reliability) between link i and j.
ri： Reliability of link i.
rj： Reliability of link j.

(a)Series connection between link i and j(b)Parallel connection between link i and j

Figure 1: Network graph for the connection of node S and G(G1,G2)
2.2.3 Model for escape safety according to the escape distance
The previous model for the evaluation of evacuation safety using
network analysis method has some weak points. Adjustments(addition or
subtraction) of nodes which can not affect the size and type of network
graph shows different network reliability. And if the connection type of
network graph is same regardless of the size, the reliability shows always
constant.

To modify these problems, the reliability, which is different from thelength, is assumed that it is changed exponentially and Gunsik,
JEONG(2007, 2008) is suggested Equation (3).
d /dr (d ) = r0 0
(3)

r ( d ): Reliability of a link at the distance of d .
r 0 : Reliability of a base link at the distance of d 0 .
d 0 : The distance of a base link.
2.2.4 Model for escape safety according to the obstacles
The evaluation model which has a consideration of escape distancewas very useful to solve many problems which can not be solved using
previous model.

However, there needs to consider more actual escape conditions to thecalculation of network reliability. So Gunsik, JEONG(2007, 2008)
suggested a new model which adopted escape obstacles to the calculation of
Quantitative Evaluation of Escape Safety Considering Extension of EscapeTime By Escape Distance And Escape Barrier

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October 2009, Incheon, Korea

network reliability and proved the adequateness and the generality using asimple network model. The change of reliability of a link, which implies achange of escape safety, according to the escape obstacles and distance on
the escape way is suggested as a Eq. (4)d/dr (d ) = r0 0 ∏ hk
(4)r(d): Reliability of a link according to the distance "d".
h k : Passing through reliability of k th door on the escape way.
Eq.(4) implies that the reduced reliability of a link due to the passing
through a door is the same condition of increased escape distance in case ofno obstacles on the escape way.
3. QUANTIFICATION OF EFFECTS BY THE
ESCAPE OBSTACLES
3.1 Classification and characteristics of escape obstacles

This investigation is based on the case of a hospital which has
publicity and much kinds of handicapped pedestrians in the view of escape.
There are 5 types of obstacles of difference of floor elevation,
inclination, width of corridor, door and crowd. Table 1 shows the detailcharacteristics of the 5 types of obstacles.
① Difference of floor elevation may occur overturning and increase
the escape time.
② Over 4°of inclination of a floor can increase the escape time.
③ Change of a effective width of a corridor increase of crowd density
and it can increase the escape time and the overturning.
④ The open ration of a door can change the safety of evacuation andalso increase the time.
Table 1: Classification and characteristics of escape obstacles
Type
Characteristics
differenceof floorelevation
inclination

width ofcorridor

door

408

It can cause overturning and affect decrease of escape velocity. A wheelchair and a
movable bed may not pass through due to the elevation. In case of step, there may bean overturning and a misstep. If it is modeled to evaluate escape safety, it can cause abottleneck effect by decrease of effective width of corridor.
If the inclination of floor is larger than 4°there occur variation of pedestrian speed ingeneral case and more larger variation of pedestrian speed using awheelchair. Especially, in a long upward slope evacuation is sometimes impossible,
and in a downward slope the increased speed cause an overturning or a collision.
Decrease of effective width of a corridor is closely related with crowd density. The
winding escape way decrease escape time and leaved things act as critical obstacles
not to allow smooth evacuation.
The door open ratio becomes effective width regardless of the corridor
width. According to the type of door, the opening time is determined and makes
stagnation to the evacuation stream. In case of the door frame is installed protruded, it
makes overturning of peoples and difficult to pass through using a wheelchair.
Generally, when the protrusion exceeds 2 cm, the pass through rate of people
decreases in emergency. Sometimes, the effective width of an emergency gate is too

New Technologies for Urban Safety of Mega Cities in Asiasmall to pass through a wheelchair or a movable bed.

crowd

The persons can be obstacles each other in the crowded situation and heavy crowd
density make increase the escape time and the overturning.

⑤ The persons can be obstacles each other in the crowded situationand heavy crowd density make increase the escape time and theoverturning.

Moreover, intensity of illumination on the escape way, heat and toxic
gases during fire, psychological instability, vibration during earthquake, andsnowfall can affect escape conditions, but they are out of limit of thisresearch and can be discussed in the next research.
Fig. 2 shows the relationship of mobility of occupants and escapetypes. The occupants are classified a group with ability and a group withdisability. Generally, normal peoples with abilities can escape with his own
ability, but peoples with disabilities need extra considerations when theyescape.
In Fig. 2, when a people with abilities is drunk, he is lacking ofmobility and power of judgement so classified as a people with disabilities
using a dotted line.
The types of escape are free walk, crutch, wheelchair, movable bed
and so on, and the left side shows large capability for self supporting escape.

Figure 2 : Classification of various escape types
3.2 Quantification of effects by the escape obstacles

The degree of effects by the escape obstacles are defined as "Degreeof Hindrance (DOH)" in this study.
When we consider if we pass through an obstacle of door, thereliability of pass through is determined by the DOH of the door.
Quantitative Evaluation of Escape Safety Considering Extension of EscapeTime By Escape Distance And Escape Barrier409

October 2009, Incheon, Korea

That is, the DOH shows the degradation ratio of reliability. Ob = 1
menas impossible to pass through the escape way due to the obstacles andOb = 0 means no obstacles on the escape way. Let the minimum escape time
is Ts at the escape distance of Ds without any obstacles on the way, and Te at
the same distance but with obstacles such as stairs, then the extended escapetime Td due to the obstacles is
Td = Te − Ts(5)
If the escape velocity is the same, the moving distance during theextended time is
Dd = Td × V0
(6)
Therefore, the extended escape time is expressed as elongation of
escape distance Ds + Dd and Eq.(7).
( Ds + Dd ) = V0 × Te
(7)
Fig. 3 shows escape distance with and without obstacle such as stairs
and the obstacle is converted as elongated escape distance.
STAIR

The stairs are converted into an elongated escape distance, so
total escape distance will be Ds+Dd.

Figure 3: Elongated escape distance by escape obstacles.
Using the Eq.(3), the calculation of reliability in case of no obstacles
that is the escape distance of Ds is Eq. (8) and in case of obstacles that is theescape distance of Ds + Dd is Eq. (9).
r ( Ds ) = r0 s

D / d0r ( Ds + Dd ) = r0

(8)
( Ds + Dd ) / d 0(9)And the DOH can be expressed like Eq. (10).
r ( D s + Dd )Ob = 1 −(10)
r ( Ds )3.3 Investigation of adaptation using simple network model

In this study, the evaluation of evacuation safety is performed more
precisely and synthetically by analyzing various obstacles on the escapeway, even though the previous works used a single value of DOH.

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New Technologies for Urban Safety of Mega Cities in Asia

Fig. 4 shows a comparison between the previous and the newly
designed network model. Simply, an escape distance and an existence andnonexistence of obstacle are used in the previous model but information
about the types of obstacles are included in the new model.
In the new network model in the Fig. 4, the length of all the links are
the same and only consider the shortest path from the node "S" to the node

Solid line: have Link without obstacles,:door,

Dotted line: Link with obstacles:step,:stair(a)Previous Network Model(b) New Network Model

Figure 4: Comparison of the previous and the new network model
Table 2 : Matrix of shortest path
Link number

1

2

3

4

5

6

7

Path1

1

1

0

0

1

0

0

Path2

1

0

0

1

0

0

1

Path3

0

0

1

0

0

1

1

Table 3 : Values of reliabilities according to
the escape types and obstacles
Free walk Assistance Crutch Wheelchair

Movable Aged
Bed
person

step

1.0

0.9

0.9

0.6

0.6

stair

0.8

0.7

0.6

0.0

0.0

0.9
0.7

door

0.8

0.7

0.7

0.7

0.7

0.7

"G". Table 2 shows a matrix to find the shortest path.
The link 2, 4, and 7 represent a door, a step, and stairs, respectively,
and DOH of each obstacles are shown in Table 3.
The reliability of a link without any obstacles is 0.9 and thereliabilities of a link with obstacles are 0.9 product each values in the Table
3. Assume that the escapes of a wheelchair and a movable bed throughstairs are impossible. So the case of path 2 and 3 are excluded.
Fig. 5 shows the calculation results of network reliability. The
previous network model can not show the difference of escape types,
however new model shows various changes of network reliability.

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October 2009, Incheon, Korea

The escapes using a wheelchair and a movable bed are
disadvantageous than free walk and it is generally accepted in the actual
situation.
This results shows deep consideration should be required in the designof hospital and social welfare facilities and it can be used for judgments ofan evacuation plan.

Netwrok Reliability

1.0
0.8
0.6
0.4
Previous Network Model

0.2

New Network ModelwithabilityAgedpersonstretcher

wheel
chair

crutchassistanceFree walk

0.0

with dis ability
Es cape ty pe

Figure 5 : Change in the escape form andnetwork reliability

4. ANALYSIS USING AN ACTUAL PLAN
4.1 Calculation of network reliability

Fig. 6 shows an actual floor plan of a hospital and it consists of 52
nodes and 54 links. Each wards are set as evacuation starting nodes and a
special evacuation stairway and a outdoor evacuation stairway are set as
finishing nodes. The floor plan in Fig. 6 is slightly changed for the several
reasons in the actual building.
Nurse rooms, storehouses, a locker room, and lavatories are excludedin the evacuation starting nodes, and two stairways inside the building also
excluded in the finishing nodes.
The neonate room and the intensive care unit are expanded to thecorridor in different from the floor plan, so the link 28 and the link 34 can
not be used as an evacuation way.
The door on the link 39 is closed all the time from the site
investigation, so it is treated as an impossible way to pass through in thisstudy.
It is impossible to move from ward to balcony but consider the path tobalcony and the path from balcony to evacuation stairway, because the412

New Technologies for Urban Safety of Mega Cities in Asia

neonates can not escape without assistances. Also compared the results tothe case of evacuation using indoor paths.
Put the distance of a base link(d0) 60 m, and reliability(r0) 0.6, and thereliabilities are 0.8 for free walk, and 0.7 for wheelchair.

Figure 6 : Network model using an actual floor plan.
Table 4 represents the reliabilities of the network according to theescape types and compared the original floor plan to the modified actual
building as a reduction ratio.

Table 4 : Comparison of the network reliability between the original floor plan andthe actual building
START NODE
Node Node Node Node Node Node Node Node Node Node Node Node Node Node Node Node Node Node
1
2
3
4
5
6
7
8
9
10
40
41
42
43
44
45
46
47
0.910 0.968 0.909 0.903 0.899 0.899 0.910 0.905 0.903 0.910 0.870 0.910 0.901 0.897 0.899 0.904 0.906 0.911

STANDARD
WHEEL(A)
0.290 0.295 0.168 0.164 0.130 0.119 0.131 0.184 0.251 0.359 0.273 0.170 0.124 0.114 0.126 0.181 0.182 0.359
CHAIR
Floor
FREE
Plan
0.436 0.485 0.325 0.334 0.295 0.282 0.296 0.347 0.397 0.484 0.421 0.341 0.283 0.271 0.285 0.341 0.342 0.483
WALKING
WHEEL(B)
0.289 0.293 0.159 0.114 0.089 0.081 0.088 0.147 0.233 0.351 0.265 0.126 0.017 0.025 0.039 0.043 0.043 0.350
CHAIR
ActualFREE
Building
0.433 0.477 0.297 0.244 0.214 0.202 0.208 0.267 0.355 0.464 0.398 0.246 0.056 0.073 0.099 0.118 0.119 0.457
WALKING
WHEEL
Reduction
0.2% 0.8% 5.6% 30.9% 31.2% 32.0% 32.9% 20.1% 7.1% 2.1% 2.8% 26.0% 86.6% 77.9% 69.0% 76.1% 76.1% 2.5%
CHAIR
Ratio
FREE
(A:B)
0.6% 1.5% 8.7% 26.9% 27.5% 28.5% 29.7% 23.0% 10.6% 4.1% 5.6% 27.7% 80.4% 72.9% 65.1% 65.3% 65.3% 5.5%
WALKINGThe escape safety from node 42 to 46 decreased remarkably than othernodes, it because the link 34 and the link 28 are excluded from theevacuation way due to the expansion of the neonate room and the intensive
care unit.

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October 2009, Incheon, Korea

Table 5 shows the comparison of the network reliability with andwithout consideration of balcony escape at the node 6 and the node 40.
It shows considerably increased reliability and safety in both cases,
and the evacuation plan using a balcony is very effective and usefulespecially to the peoples with disabilities.

5. CONCLUSIONS

The development of quantitative evaluation tool for actual escapesafety is performed by the analysis of various escape obstacles and types
and it is evaluated using an actual floor plan of hospital.
Main achievements of this research are like belows.
① Classification and analysis of escape obstacles by the investigationof design drawings and previous works.
② Investigation of human characteristics related evacuation andescape type according to the mobility.
③ Derivation of a function to convert the delay of escape time due toobstacles to the elongated escape distance.
④ Development of actual evaluation tool for escape safety by the
combination of the previous model and the derived function.
The escape way of short and no obstacles is always best in theprevious network analysis, however this research proved that it may bechanged according to the escape type and obstacles even it is shortest way.
For more accurate analysis, analytical and experimental investigations areneeded simultaneously, and it will be performed in the future.
A remodeling or a change of floor plan are necessary because all thechanges can not predict at the initial design stage, but it should be very
careful if it has bad influences to the basic function of building, especially inthe view of safe evacuation.
It is anticipated to be used to design a hospital, and social welfare
facilities where are aimed to accommodate peoples with disabilities and to
be designed evacuation plan using a balcony.

REFERENCES

Choi, Jae-Pil Kim, Min-Seok Choi, Hyun-Chull. 2006. Development of
Evacuation Cost Analysis Method Based on Euclidean Distance with Visual
Depth, J. Archit. plan., AIK. No. 22, 115-112
Oh Jung Woo, Kim Kyung Hwan, Lee Yoon Sun, Kim Byeong Su, Kim
Whoi Yul, Kim Jae Jun. 2007. Network Model for Managing Interior Spacein Real-Time, STPAM of AKJCEM. KICEM, pp.840-843

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Kim, Jong-Hun Joo, Sung-Yong Lee, Jurng-Jae. 2007. An Evaluation on
Evacuation Safety in Multiplex Cinema based on Fire & Evacuation
Simulation, Vol.1, No.1, KIAEBS pp.7-13
Gunsik JEONG and Hidemasa YOSHIMURA. 2007. Quantiative
Estimation of Escape Safety in Buildings Considering Eecrease of
Reliability According to Escape Distance, J.Archit. Plann., AIJ, No. 616,
71-76
Gunsik JEONG and Hidemasa YOSHIMURA. 2008. Quantitative
Evaluation of Escape Safety in Buildings Considerirng Decrease of
Reliability by Escape Barrier, J.Archit. Plann., AIJ, No. 625, 551-557,
Mikio TAKAGI, Hirokuni TANIGUCHI and Jong-seok KIM. 1991. Basic
Study of Indexes of Grapbs and Networks and Analysis of Street Structuresof Underground Towns by Applying Them, J.Archit. Plann., Environ.
Engng, AIJ, No. 422, 37-44
Yoshitsugu AOKI, Haruyuki FUJII and Yoshiro KINOSHITA. 2001. A
Modeling of Expert-Judgement on Fire Safety Evaluation, J.Archit. Plann.,
Environ. Eng, AIJ, No. 546, 149-154
Shigeyuki OKADA and Nobuhiro KURDA. 2003. Study on The Evaluationof Seismic Casualty Risk Potential in Dwellings, J. Struct. Constr. Eng., AIJ,
No. 563, 83-89
Hiroki MURAI, Kouji SHIDA, Takeshi YATOGO and Kan MOMURA.
2002. Study on The Refuge and Safety in The Fire at Nursing Home and
Health Care Facilities, J.Archit. Plann., Environ. Eng, AIJ, No. 551, 181187
Hidemasa YOSHIMURA. 1987. On Measuring Escap Ability from A Maze,
J.Archit. Plann., Environ. Engng, AIJ, No. 375, 49-56
Hidemasa YOSHIMURA. 1989. A Metrical Evaluation of The Arrangementof Fire Escapes by Goal Programming, J.Archit. Plann., Environ. Engng,
AIJ, No. 403, 9-20
Hidemasa YOSHIMURA. 1992. An Evaluation Method of Escape Safety of
Building Plans Based on Weights of Safety Indexes Estimated AHP
Analysis, J.Archit. Plann., Environ. Engng, AIJ, No. 437, 87-96
19.N.B.Berlin. 1980. A Modeling Procedure for Analyzing the Effect of
Design on Emergency Escape Potential. PB80-204738

Quantitative Evaluation of Escape Safety Considering Extension of EscapeTime By Escape Distance And Escape Barrier

415

PROPOSAL OF AN EVACUATIONNAVIGATING SYSTEMIN CASE OF NATURAL DISASTERAYAKO FUKUSHIMA1, BYONG-PYO JEONG2, ATSUYUKI IDA3,
SHIN’ICHI TSUCHIYA4, YUJI HASEMI5
1
Graduate student, Waseda Univ., Japan
2
National Institute of Information and Communications Technology, Japan
3
Visiting Research Associate, Research Institute for Science andEngineering, Waseda Univ. M. Eng., Japan
4
Visiting Researcher, Research Institute for Science and Engineering,
Waseda Univ., PhD, Japan
5
Prof, Department of Architecture, Waseda Univ., Dr.Eng., Japan1
a_fukushima@akane.waseda.jp
2jeong@nict.go.jp
3
ida@kurenai.waseda.jp
4tsuchiya@afri.jp
5hasemi@waseda.jp

ABSTRACTJapan is well known as a country being hit by strong earthquakes that
may make numerous victims and collapse. After a heavy earthquake,
information networks and infrastructure could be disconnected for several
days. In the case of those disconnections, every victim, even the person who
have no difficulty in evacuating, are capable to become vulnerable people
because they could not make any decisions due to lack of information.
Especially, people that are not able to acquire and utilize informationsuch as Foreigners with less Japanese communication skill and lessexperiences of earthquakes will be placed in disadvantaged situations.
Therefore, Navigating Evacuation System (HINAVI; HInan(=Evacuation)
NAVIgation system) is proposed as an information providing system withinterface to make evacuating activity easier and safer.
The system is composed of several functions as follows; Evacuation
guidance, SOS-maps function, Family Safety Confirmation, Citizens
Information Application function, Translation and Risk Forecasting
function.
This paper mainly deals with the evacuation guidance and SOS-maps
function to rescue activities of the buried alive person. GPS (Global
Positioning System) and GIS (Geographic Information System) are applied
to these functions. Technical problems that need to be resolved are also
discussed.

417

October2009, Seoul, Korea

1. INTRODUCTION
As a typical damage of great disaster, telephone disconnection andtraffic damage are expected. Under that circumstance, information requisite
for evacuation would be unacquirable even for a person with normal
functional capacity. And then, their evacuation will delay and might becaught in dangers.
In addition, the number of foreigners visiting Japan for the purpose ofbusiness and sightseeing has increased in recent years. Because of theirinexperience in earthquake, there is a higher possibility that they will delayin evacuating.
Caused by diversification of traffic networks and lifestyles, even Japanese
has high risks that they will be hit by disaster in unusual situation such as in
a new place, transport facilities and so on. Those situations may cause theirless level judgment and great confusion.
On the other hand, from a viewpoint of rescuing a large indefinite number,the difficulty of determination of the extent of the damage will make proper
placement of rescue crews difficult.
Therefore, it is imperative that victims make judgments and actions
themselves, and that rescue crews determine the extent of the damage
correctly.
In this paper, we will aim disaster mitigation focusing on the role ofinformation that will assume in case of disaster. We will study how
information should be provided for people that are not able to acquire andutilize information, and propose HINAVI system.

2. BASIC CONCEPT of HINAVIThere are very few information providing systems that combine
scattered information depending on individual attribute and location, thoughvarious information needed for evacuation and rescue after disaster(Fukushima et al, 2008). From viewpoint of disaster victim, it is needed tomake a reasonable selection among massive amount of information spreadout for public and to make some decision and action. However, proper
decision-making is not facile for anybody, and difficulty for the
disadvantaged is expected.
Therefore, we advance structure of information providing system (HINAVI;
HInan(=Evacuation) NAVIgation system) that helps efficient information
accession and evacuation behaviors. These information and data aresupposed to be exchanged via portable devices (e.g. Mobile phone).
An example of evacuation activities of a HINAVI user is figured in Figure 1.
HINAVI is activated and starts help user in town A evacuate just after
earthquake has happened. Around the same time, situation of damage andusage of temporary evacuation area (B park), aid station for injured (Chospital) and evacuation center(D elementary school) are aggregated andreflected to evacuation routes. In the result, the route to Park B, which is themost accessible park from town A, is displayed and the user walk to Park B
based on the guidance. Based on the information that the user has received

418

New Technologies for Urban Safety of Mega Cities in Asia

minor injuries, the user stops at C hospital for treatment on the way to
refuge center, D elementary school.
If the user is visited by earthquake near the high-risk coast of tsunami
disaster, HINAVI issues a tsunami warning and urges quicker evacuating. In
the case of the user turned into unconscious under collapse, rescue crew that
got the report rushes to the site, transports him to C hospital that can accept
patients. In Addition, the system enables users inform their conditions to thefamilies far away during evacuation life.

Figure 1: An example of evacuation activities of a HINAVI user
In this system, information that transacted in the case of emergency isclassified into Inputs and Outputs. Inputs from victims to providers (Theorganizations retaining information) come to “Components that affectfiltering of providing information” and Outputs from provider to victims are“Necessary information” as figured in Figure 2.
Existing model
ProviderHINAVI model
ProviderInputs=individual attribute, conditionLargeamountofinformation

ProperOutputs

VictimUsers are forced to make a choicefrom a great deal of information
sent from provider.

VictimProvider outputs the information
proper to users based on individual
attribute and situation.(via personal
device)Figure 2: Models of information transaction(comparing existing model and HINAVI model)
Inputs are divided into “Advance registration inputs” such as age, sex, and“Post-Disaster inputs” are grasped after earthquake happened such as thecollapses and the injuries. Table 1 shows correspondences between Inputs
and Outputs. Corresponding Advance registration inputs are figured as O,
and Post-Disaster inputs are described with implements and contents.

PROPOSAL OF AN EVACUATION NAVIGATING SYSTEM IN CASE OF NATURAL DISASTER

419

October2009, Seoul, Korea

Post-Disaster inputs can be divided into “Inputs rely on self-diagnosis” and“Inputs remotely-monitored”.
#1 Inputs rely on self-diagnosis are as follows; Physical status (injuries,
fatigue), Report of the fires and collapses happened in one’s neighborhood.
#2 Inputs remotely-monitored are as follows; Damage of the area
undesignated a temporary refuge area for application as a refuge,
Congestion condition of refuge centers.
According to inputs combined individual attribute and environmental
condition, personal directions and information will be output (Table 2). It isnecessary to construct the system that allows “facile and propertransmission” from victims to provider and “quick and precise provision of
information” from provider to the victims.

Table 1: Correspondences between components affect filtering of providing
information (Inputs) and Information provided by HINAVI (Outputs)

Advance registration
Post-Disaster

INPUTS

Earthquake
fundamental
information
Earthquake
experience
Language
Sex
Age
Health condition
LocationHome address

Evacuation
direction

OUTPUTS
Surrounding
Evacuation area
dangerinformation

Water
supplement &ToiletEvacuation
Centerinformation

O
O
O
O
O

O

O
O

O

O

O
O

O
O

Remotelymonitored

Sensoracquired info.
of bldg.

Sensoracquired info.
of candidate
site

Rely on selfdiagnosis

Detailed
location

O

O

O
O

O
SensorDamage of the Congestion of
acquired info.
toilet andevacuationof bldg. andchannelcenterroads
VisualPhysical statusobservation

Table 2: Name and content of information provided by HINAVI (Outputs)
Style

Content

ExampleThis shaking is "Earthquake".
Earthquake fundamental Information about earthquake forCalm down and evacuate to wide space withinformation
inexperienced victims
alerting to fires and collapses.
Information about appropriate
Evacuation direction
Use the stairs to ground floor noting overheadactions
Information about a large spaceYour nearest evacuation area is **park.
Evacuation area
to avoid from spread of fire.
It takes 5 minutes by foot.
Location and route.
Surrounding danger
Information about surrounding
The road is cordoned off in 100 meters.
information
danger (fires, collapses)
Information about water
Turn to the right and take a rest in convenience
Water supplement & Toilet supplement and toilet during
store.
evacuation
Information about the life in
Evacuation Center information evacuation center. Location and Your evacuation center is OO elementary school.
route.

3. FUNCTIONS INCLUDED IN HINAVI
3-1 The function of evacuation route guidance

420

New Technologies for Urban Safety of Mega Cities in Asia

Key function of HINAVI is route guidance. The rough flow of usage
in the case of earthquake is as follows (Figure 3);(1) The users enter their information about attribute such as sex, age and soon in advance. (Advance registration inputs)(2) After earthquake happens, entries of injuries condition by users and ofdamages such as collapses and fires by remote sensors are aggregated.
(Post-Disaster inputs)(3) As guiding them depending on the situation, this system assists their safe
and comfortable evacuation.

Figure 3: Flow of HINAVI usage (from a viewpoint of user)
Just after earthquake, “Earthquake fundamental information” and“Evacuation direction” will support their start of safe evacuation. During
evacuation by walk, the user is navigated according to ”Evacuating Area
Information”, “Evacuating Center information” about his own evacuate
areas or centers. As necessary, HINAVI informs the user an alternative pathwhen they approach dangerous area in order to avoid secondary disaster(Surrounding danger information). “Water Supplement & Toilet” will maketheir evacuation safer. (Figure 4)
It is necessary that the system possesses some functions for efficientevacuation route guidance depending upon the situation.
(1) Risk forecastingThis function is to determine and present degree of risk of the present
location mainly by “Post-Disaster inputs”. The user with no experience ofearthquake will be urged to evacuate, as a result keeps himself in safety.

(2) Citizen Information application

PROPOSAL OF AN EVACUATION NAVIGATING SYSTEM IN CASE OF NATURAL DISASTER

421

October2009, Seoul, Korea

This function is to aggregate the information of fires and collapses gatheredby users evacuating, and to use that information as indications of rescue andfire fighting.
(3) Translation
This function aims to maintain minimum communication skill even though
all of the communication facilities are interrupted and real-time information
is deprived.
(4) Prehension assistantThis function complements information for prehension and action when
information is inadequate for user.
As it gives the users explanation about vocabulary (such as “Temporary
evacuate aria”) and systems (such as life in evacuate center), it will supply
lack of knowledge and encourage appropriate behaviors.

Evacuation
Route
Receivingpoint【地震基礎】
今の揺れは
地震です
慌てず
広い場所に
逃げてくださいHINABI
Display
image【Earthquake
foundation】
This tremor is
Earthquake.
Calm down andmove to broad
area.

【Surrounding
danger】【Evacuationarea】

Fire!!
100m ahead on
your way.

Nearestevacuation area
is ** Park.

【Evacuation
direction】
Tsunam(Big wave)
might occur.
Leave the coast

InitialLocation** Park
Fire【Water/Toilet】
Turn to the rightand take a rest at
the store.
Have some water.

Store【Evacuation
Center】
Yourevacuation
center is ○○elementary
school.

○○ Elementary
schoolFigure 4: Image of route guidance(5) Family Safety confirmation

422

New Technologies for Urban Safety of Mega Cities in Asia

This function assists the relatives confirm the safety of user. As the past has
already shown, for foreigners struck by earthquake in Japan were forced tocontact their family through embassy or international phone call. Those
actions are often hampered by communication troubles or long-distancemovement to embassy location. Therefore, this function is proposed torealize communication among family members through portable device.
The application of these functions in parallel with route guiding
might realize proper information provision to individuals.
3-2 SOS-maps function
SOS-maps function is to make rescue easier with prehension oflocation and condition of victims when disconnection for a given length oftime or impossibility of evacuation by one's own ability are occurred. This isessential function required right after great earthquake under chaos and lifethreatening condition. In the Great Hanshin-Awaji Earthquake, 1995,
150,000 people had been buried alive and 35,000 of that had been unable toevacuate on one's own (Yamamura, 1995). Since amount of collapses
happen over large areas, the strong cooperation among neighborhood
residents and public rescue crews is necessary. This can be achieved bycollection and sharing information about victims waiting for recues.
However, it is difficult to collect information about damage under disastersituation, and there are few interagency information sharing systems.
Figure.5 is showing outline of SOS-map function (SOS-map function
includes identification of location by GPS and visually-adjustment anddisplay by GIS.) and immediate rescue structure with information
unification.
SOS signal
Buried alive victim

SOS-map
Government
Prefecture

Ward, City
Evacuation
center

CONTENTSACTION

Extensive damage in XX division.

Demand the rescue
in the seriously damaged area

A number of buried
alive persons in YY city.

Demand the rescue
to the government

Location of buried alive person withdifficult situation and fire site.

Rescue work of heavy buried alive persons
Fire extinguishment

Location of buried alive person.
Detailed information
about buried alive person.

Confirmation of family members' safety.
Confirmation of the buried alive persons' safety
around evacuation center.
Rescue work. (Only low risk case)

Figure 5: Survey of SOS-map function(Contents and action of relevant organizations)
Some efficient functions for relief of victims and readily feasible
with existing technologies are as follows:
1. Determination of location of buried alive person with the mobile phoneequipped with a GPS location service

PROPOSAL OF AN EVACUATION NAVIGATING SYSTEM IN CASE OF NATURAL DISASTER

423

October2009, Seoul, Korea

By comparing the coordinate of user before and after earthquake, their
movement is determined. It determines the user is a buried alive person or
not based on displacement of user’s device and location before hit byearthquake. (Table 3)
Table 3: Guideline for determination of buried alive person by location
information
Indoors or
Location
Outsidebefore theCalculated
quake
collapse ratio
Move of the user
after the quake
Determination

IndoorshighhighOutsidelow

low

moved stayed moved stayed-

Buried
alive

-

-

high

high

low

low

Unclear(Disconn
ection)moved stayed moved stayed-

Buriedalive--

Buriedalive

2. Display of SOS-maps of buried alive persons with GIS
Figure.6 shows an example of SOS-map composed of location information(mentioned at 1.) and post-disaster inputs.
Since the category and the scope of required information differ according toorganization, it is necessary to draw a map corresponds well to eachorganizations’ needs and to share it widely. Organizations, such as firecompanies and neighborhood residents, refer to SOS-map and cooperate in
rescue activities.

ID: 0001
Name: Taro Yamada
Age: 22
Housemate: 1
Address: Shinjuku ward, xxx

ID: 0002
Name: Hanako Suzuki
Age: 42
Housemate: None
Address: Shinjuku ward, yyy◎：Location of buried alive person□：Advance registration information of user

Figure 6: Contents about buried alive victim displayed on SOS-map

424

New Technologies for Urban Safety of Mega Cities in Asia

3-2-1 Future tasks of SOS-maps function
When the victim is in underground area or communication knocked
out area, it is difficult to determine locations of buried alive persons becauseof difficulty of accession of location. Expansion of range of communication
with GPS relay-antenna, Wi-Fi and RFID technology is needed. Further totechnical issues, role-sharing arrangement and upgrading of
telecommunication networks are demanded to achieve the cooperation
among some organizations such as refuge centers, fire department and so on.

4. CONCLUSION
We discussed about the information provision responding to individual
condition, and we proposed HINAVI in this study.
The entire system includes technical problems as follows;(1) Securing the availability of the base station.
In the past heavy earthquake, large amount of communications traffic
concentrated to the local basement and caused the congestions. It is also
necessary that the base station facilities will be enhanced earthquake safety
or dispersed. Adoption of other network technologies (such as peer-to-peer
network) needs to be explored.
(2) Securing the power supply of the cellular phone terminals.
It is difficult to supply power to the personal cell phone terminals ,though
early restoration of power supply is expected. Because under suchcircumstance, continuity of medical activity or operation of refuge will begiven priority over individual usage.
In the case of past earthquake, probability of survival of rescuees had
reduced 3 days later (Iokibe, 1996). Therefore, as considering SOS-map
function usage, the devices should work as long as 3 days when it isnormally charged.

REFERENCES
Fukushima, A., Tsuchiya, S., Ida, A., and Hasemi, Y., 2008, Proposal of a
Navigating Evacuation System in Case of Natural Disaster for Foreigners,
Summaries of technical papers of annual meeting AIJ 2008, A-2, pp.11-12(in Japanese)
Yamamura, T., 1995, Self-disaster prevention organizations (Their missions
and activities), Bousai System Kenkyu-jo. (in Japanese)
Iokibe, M., 1996, Risk Management-Response taken by Government,
Hanshin-Awaji Daishinsai-shi , Asahi Shimbun Japan, p.347. (in Japanese)

PROPOSAL OF AN EVACUATION NAVIGATING SYSTEM IN CASE OF NATURAL DISASTER

425

INFLUENCE OF THERMAL CONDITION ON
THE WIND ENVIRONMENT EVALUATIONFOR BUILDING DESIGNHONG HUANG1, RYOZO OOKA2, HOM B. RIJAL2,
TAKEAKI KATSUKI2 and BYOUNGCHULL OH2
1
Center for Public Safety Research,
Tsinghua University, Beijing, 100084, P.R. China
hhong@tsinghua.edu.cn
2
Institute of Industrial Science, The University of Tokyo,
4-6-1 Komaba, Meguro-ku, Tokyo, Japan{ooka,rijal,wtakeaki,ohbc}@iis.u-tokyo.ac.jp
ABSTRACT
Computational Fluid Dynamics (CFD) simulation has become apowerful tool for wind environment evaluation for building design. In thisstudy, the wind environment in an existing urban block is investigated underisothermal and non-isothermal conditions in summer daytime (15:00) using
CFD simulation. The wind velocity under non-isothermal conditions is
considerably higher than isothermal conditions. This is probably a realistic
prediction considering the actual thermal environment in the urban block. It
is concluded that consideration of non-isothermal conditions is required innumerical simulations for wind environment evaluations of urban blocks
and building design. The linear regression equation is proposed to predict a
realistic wind velocity for the urban block.
1. INTRODUCTION
The wind environment evaluation for new building design is usually carriedout experimentally in wind tunnels. However, following the development ofComputational Fluid Dynamics (CFD) simulation technology in recent
years, CFD has become a powerful tool for wind environment evaluation.
When a wind environment is evaluated by numerical simulation, isothermal
conditions are often used (Hu et al, 2005) by assuming a large wind velocity
compared with the atmospheric stability and instability effect (Bulk
Richardson number is small). Huang et al (2008) carried out a CFD analysis
on traffic-induced air pollutant dispersion under non-isothermal condition in
a complex urban area. However, there has been little research on windenvironment evaluation for building design in actual urban blocks under
non-isothermal conditions. Therefore, this research focuses on an actual
urban block, and the wind environment was evaluated by CFD simulation
under both isothermal and non-isothermal conditions. The investigated area
is located in a very dense urban area with mid-rise and high-rise buildingsthat include offices, commercial and residential buildings, which is shownin Figure 1.

427

October 2009, Incheon, Korea

2. METHOD DESCRIPTIONIn this research, the coupled simulation of radiation and convection wasused (Huang et al, 2005 and Yoshida et al, 2000). At first, the radiation
calculation was performed, and this result is used for the CFD simulation.
Three-dimensional city model data (Remote Airborne Mapping Systems-E(RAMS-E), Kokusai Kogyo Co., Ltd.) measured by an aircraft equippedwith a laser scanner are used. In this data, the heights of buildings and theterrestrial surface are precisely measured by a laser scanner from the aircraft.
The three-dimensional city model data is first read by CAD software, andthen converted into Initial Graphics Exchange Specification (IGES) fileformat. After this, the IGES file is read by the computational grid-making
software (Gridgen, VINAS Co., Ltd.). An unstructured computational meshis constructed which is an effective means of conducting a CFD simulation
in a complex urban block. RADX software was used for the radiation
calculation (Ooka et al, 2006) and the commercial CFD code StarCD wasused for the convection calculation.
River

1700m

N

Target area

1700m

Figure 1: The simulated urban block, with the main ‘target area’ indicatedwithin the dotted line
The date and meteorological conditions are shown in Table 1. The analysis
date is 23rd July and the investigated time is 15:00 which is a fine summer’sday. The wind velocity was 1 m/s at 18 m above ground level. The
prevailing wind is southerly at the simulated time. The air temperature is
31.6°C at the same height.
The radiation calculation conditions are shown in Table 2. The Discrete
Transfer Method (DTM) is used in the radiation simulation. All thebuildings have concrete walls with 0.22 m thick. The radiation calculation
was conducted in an unsteady condition, and the pre-calculation time is 15
hours. The surface temperature, which was obtained from the radiation
calculation, is used as a boundary condition in the CFD simulation.

428

New Technologies for Urban Safety of Mega Cities in Asia

The CFD calculation conditions are shown in Table 3. The vertical windprofile of the inlet followed the 1/4 power law. The turbulent model is astandard k-ε model. Discretization is based on the Finite Volume Method(FVM) and the algorithm is the SIMPLE method. A first-order upwind
scheme was used as the differencing scheme. The side boundary is no slip,
while the sky boundary is free slip. The generalized logarithmic law withthe parameter E=9 was applied to buildings and the ground surface assmooth walls. The dimension of the computational domain is 1,700 m (x) ×1,700 m (y) × 600 m (z) with a mesh size of 810,642. In order toinvestigate the effect of the temperature, the CFD simulation was performed
under both isothermal and non-isothermal conditions.
Table 1: Meteorological conditions
Day and time
Wind direction
Wind velocity
Air temperature
LatitudeLongitude

23 July (15:00)
Southerly
1 m/s (18.0 m above ground level)
31.6°C35.18°N
136.90°E

Table 2: Boundary conditions for the radiation calculation

Building

GroundRiver

Wall
Solar reflectivity
Solar transmittanceThickness
Conductivity
Indoor convection heat transfer
coefficient
Indoor air temperatureLong wavelength emissivity
GroundSolar reflectanceLong wavelength emissivity
Underground temperature
Surface temperature

Concrete0.1
00.22 m1.64 W/(mK)4.64 W/(m2K)
26°C
0.9
Asphalt
0.1
0.9
26°C (0.5 m below ground level)
28°C

Table 3: Conditions of the CFD calculation (Huang et al, 2005)
Turbulent model
Discretization
Algorithm
Differencing scheme
Side
Sky
Wall

Inlet (Power law)

Turbulent kinetic energy (k)Standard k-ε model (inclusion of
buoyancy effect)
Finite volume method
SIMPLE method
First-order upwind scheme
No slip
Free slip
Generalized logarithmic law
U = U0(Z/Z0)0.25, Z0=18.0 m, U0=1.0 m/s
Z0: Representative height(meteorological station) (m)U0: Wind velocity at Z0 (m/s)
Z: Height from the ground level (m)U: Wind velocity at Z (m/s)
k=1.5(IU)2, I=0.1
I: Turbulent intensity

Influence of Thermal Condition on The Wind Environment Evaluation for Building Design429

October 2009, Incheon, Korea

Turbulent kinetic energy dissipation rate (ε)
Turbulence length scale (l)ε=Cμk1.5/l, Cμ=0.09
l=4(Cμk)0.5Z00.25Z0.75/U0

3. RESULTS AND DISCUSSION
3.1 Surface temperature distribution
The distribution of the surface temperature, which was obtained fromthe radiation calculation at 15:00, is shown in Figure 2. Due to the influenceof solar radiation, the variation in surface temperature of the buildings or
ground is high in the shaded and non-shaded areas. The sun is in thesouthwest direction at 15:00 and thus the surface temperature of the southand west-facing walls is higher than the north- and east-facing walls. The
surface temperature of the roof rises to 56°C due to the effect of direct solar
radiation. The surface temperature is about 50°C on the south- and westfacing walls, and about 40°C in the north- and east-facing walls. The surface
temperature of the ground is about 50°C in areas exposed to the sun, andabout 40°C in shaded areas. These surface temperatures are used as theboundary conditions under non-isothermal conditions.
3.2 Air temperature distribution under non-isothermal condition
The horizontal air temperature distribution at 1.5 m above groundlevel is shown in Figure 3. The mean and standard deviation are shown in
Table 4. The air temperature is high around the area where the surface
temperature is also high. Due to the effect of the river, the air temperaturenear the river is about 0.5K lower than the urban areas. Due to poor
ventilation, heat is likely to accumulate in the densest spaces (alleys, narrow
spaces) and thus the air temperature is highest in such areas. Conversely, theventilation is good in open spaces (wide streets, open land) and thus the airtemperature is comparatively lower there.
The vertical temperature distribution across the A-A’ section isshown in Figure 4. The mean and standard deviation are shown in Table 4.
The vertical temperature distribution decreases as the height increases. This
result shows that an unstable layer is formed near ground level. The verticaltemperature distribution of the whole calculated area is shown in Figure 5.
The Bulk Richardson number is about -14.4 when the maximum buildingheight of the calculated area is taken as the representative length, whichshows an unstable condition. There are many buildings up to 50 m above
ground level, and thus the temperature gradient is small. The number ofbuildings decreased above that height and thus the temperature gradient islarge.
3.3 Relationship between the air temperature and wind velocity under
non-isothermal conditions
The correlation coefficient of the air temperature and wind velocity
is shown in Table 4. The correlation coefficient is relatively high (0.50 ~430

New Technologies for Urban Safety of Mega Cities in Asia

0.65) in the lower parts of the urban area (0.5 ~ 75 m). The coefficientdecreases significantly above that height. The results showed that theNoCN(a) South- and west-facing walls(b) North- and east-facing walls

Figure 2: Distribution of the surface temperature in the ‘target area’
A
N
oC

River

B3

B2
B1

A’

Figure 3: Horizontal air temperature distribution at 1.5 m above groundlevel across the ‘target area’
B1, B2 and B3 indicate the buildings which appear in the cross-section.
oC

B1

B2

B3

Figure 4: Vertical air temperature distribution at A-A’ section‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐
Bulk Richardson number (Rb) is calculated using the following equation and parameters.

Rb =

T −T
gZ
× a 2 s(T + 273.15)
U

g: Acceleration due to gravity (9.8 m/s2), Z: Calculated height (100 m), T: Mean temperature (38.3°C),
Ta: Air temperature at Z (31.6°C), Ts: Surface temperature (45°C), U: Wind velocity at Z (1.71 m/s)

Influence of Thermal Condition on The Wind Environment Evaluation for Building Design431

October 2009, Incheon, Korea

250

Height (m)

200
150
100
50
0
31.5

31.6

31.7

31.8

31.9

32.0

32.1

32.2

32.3

32.4

32.5

Mean air temperature (o C)

Figure 5: Vertical air temperature distribution of the whole calculated area
(The figure is derived from the mean value shown in Table 4)
Table 4: Mean, standard deviation (SD) and correlation coefficient of the
air temperature and wind velocity across the entire calculated area
Height(m)

NumberofmeshesAir temperature
To (°C)Wind velocity (m/s)

Mean

SD

Non-isothermal
V
Mean
SD

a

Correlation coefficient (r)Isothermal Vi

To:V

V:Vi

Mean

SD

rb

p

r

p

0.5

11,362

32.5

0.4

0.88

0.48

0.41

0.33

-0.54

<0.0010.65<0.001

1

11,362

32.5

0.4

0.88

0.48

0.41

0.33

-0.54

<0.0010.64<0.001-0.54<0.0010.64<0.001-0.54<0.0010.64<0.0010.64<0.001

1.5
2

11,362
11,362

32.4
32.4

0.4
0.4

0.88
0.89

0.48
0.47

0.41
0.42

0.33
0.33

3

11,362

32.4

0.4

0.90

0.47

0.42

0.33

-0.52

<0.001

5

11,362

32.3

0.4

0.92

0.46

0.43

0.32

-0.51

<0.0010.63<0.001

7

11,362

32.3

0.3

0.95

0.46

0.44

0.33

-0.50

<0.0010.62<0.001

10

11,362

32.2

0.3

0.99

0.45

0.46

0.33

-0.50

<0.0010.61<0.001

15

11,362

32.1

0.3

1.06

0.45

0.51

0.33

-0.54

<0.0010.58<0.001-0.59<0.0010.54<0.001-0.65<0.0010.45<0.001-0.65<0.0010.38<0.0010.34<0.00120
30
40

11,362
11,362
11,362

32.0
31.9
31.8

0.3
0.3
0.3

1.14
1.32
1.47

0.44
0.42
0.38

0.58
0.76
0.94

0.32
0.28
0.25

50

11,362

31.8

0.3

1.55

0.34

1.09

0.22

-0.62

<0.00175

11,362

31.7

0.2

1.66

0.27

1.35

0.16

-0.50

<0.0010.35<0.001

100

11,362

31.6

0.2

1.71

0.23

1.53

0.11

-0.37

<0.0010.38<0.001

125

11,362

31.6

0.2

1.77

0.19

1.66

0.05

-0.23

<0.0010.34<0.001150

11,362

31.6

0.1

1.81

0.15

1.76

0.03

-0.03

<0.0010.28<0.0010.08<0.0010.31<0.0010.07<0.0010.32<0.001

0.00

0.916

0.31

<0.001-0.11<0.001

0.24<0.001

175
200
225
250

11,362
11,362
11,362
11,362

31.5
31.5
31.5
31.5

0.1
0.1
0.1
0.1

1.85
1.88
1.92
1.95

0.12
0.10
0.07
0.06

1.83
1.89
1.95
1.99

0.03
0.03
0.03
0.03

<0.001<0.001
All
238,602
32.0
0.3
1.35
0.33
1.01
0.21
-0.79
0.82
The number of meshes is equal at each height because all values are extracted using the mesh at ground level. Thus, thevalues are interpolated in the upper parts of the urban area where the same mesh does not exist.
b
Even though some of the correlation coefficients are quite small or zero, they are included in the overall model because thisprovides a higher correlation coefficient.
p: Significant levelacorrelation coefficient is different with and without buildings present, sincethese affect the air temperature and wind velocity. The correlation between
the air temperature and wind velocity of the whole calculated area is
illustrated in Figure 6. The linear equation, which is obtained from theregression analysis, is shown in Equation 1.

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New Technologies for Urban Safety of Mega Cities in Asia

To=-0.662V+32.9 (n=238,602, r=-0.79, p<0.001)(1)

Air temperature To (oC)where, To is the air temperature, V is the wind velocity under nonisothermal condition, n is the number of meshes, r is the correlation
coefficient, and p is the significant level of the correlation coefficient or the
regression coefficient. The correlation coefficient is high (r=–0.79) and theequation is statistically highly significant (p<0.001). This means that the airtemperature is high when the wind velocity is low, and the air temperature is
low when the wind velocity is high. Due to the low wind velocity, the airtemperature is high in the lower part of the urban area.

Wind velocity under non-isothermal condition V (m/s)

Figure 6: Relationship between air temperature and wind velocity acrossthe whole calculated area
(The figure is derived from all data shown in Table 4)
3.4 Wind velocity under isothermal and non-isothermal conditions
The distribution of the wind velocity vector at 1.5 m above groundlevel under isothermal and non-isothermal conditions is shown in Figure 7
and the differences of the wind velocity scalar are shown in Figure 8. Meanvalue and standard deviation are shown in Table 4. The wind velocity in the
open areas is high, but is low in dense areas. The variation in wind velocity
under isothermal and non-isothermal conditions is high, and in most areas,
the wind velocity under non-isothermal conditions is higher than isothermal
conditions (Figure 8). As indicated by dotted circles in Figure 7, the windflows from the urban areas back to the river under isothermal conditions,whereas under non-isothermal conditions, such flow is reversed. The results
showed that the cool air generated by the river flows into the urban areas
due to the southerly wind under non-isothermal conditions.
The vertical distribution of the wind velocity vector under isothermal
and non-isothermal conditions is shown in Figure 9. The wind velocity
under non-isothermal conditions is high, and a strong vertex is found in theleeward side of the buildings due to the temperature gradient. In order tocompare wind velocity under isothermal and non-isothermal conditions

Influence of Thermal Condition on The Wind Environment Evaluation for Building Design433

October 2009, Incheon, Korea

across the entire calculated area, the vertical distribution of the windvelocity is shown in Figure 10. For reference, the wind velocity as
calculated by the power law (Table 3) is also shown.
B

C
N

River

River

B3

B3
m/s

B2

B2

B1

B1

B’

C’

(a) Isothermal conditions(b) Non-isothermal conditions

Figure 7: Horizontal distribution of the wind velocity vector 1.5 m above
ground level across the ‘target area’

N

River

m/s

Figure 8: Horizontal wind velocity differences under non-isothermal andisothermal conditions 1.5 m above ground level across the ‘target area’

m/s

B1

B2

B3

(a) Isothermal condition (B-B’ section of Figure 7)

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New Technologies for Urban Safety of Mega Cities in Asia

m/s

B1

B2

B3

(b) Non-isothermal condition (C-C’ section of Figure 7)

Figure 9: Vertical distribution of the wind velocity vector across the ‘target
area’
250
Isothermal
200

Non-isothermal
Power law

Height (m)

150
100
50
0
0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Mean wind velocity (m/s)

Wind velocity under non-isothermal condition V (m/s)

Figure 10: Vertical distribution of wind velocity across the entire calculatedarea (The figure is derived from the mean value shown in Table 4)Wind velocity under isothermal condition Vi (m/s)

Figure 11: Relationship between wind velocity under isothermal and nonisothermal conditions across the entire calculated area (The figure isderived from all data shown in Table 4)
The wind velocity across the urban area increases with height.
However, standard deviation of the wind velocity is small as the heightincreases. The reason could be that the wind velocity is stable in the upper
regions of urban areas due to the decrease in the number of buildings. In thelower part of the urban block, the wind velocity under isothermal conditions
is smaller than the wind velocity as per the power law. One reason could bethat the wind velocity might decrease due to obstruction by the buildings.
On the other hand, the wind velocity under non-isothermal conditions ishigher than the wind velocity as per the power law. The reason could be thatthe wind is stimulated by the buoyancy effect. The difference in wind

Influence of Thermal Condition on The Wind Environment Evaluation for Building Design435

October 2009, Incheon, Korea

distribution under isothermal and non-isothermal conditions starts todecrease from about 100 m above ground level. This is because there arefew buildings above that height and the buoyancy effect is also small.
The correlation coefficient of the wind velocity under isothermal andnon-isothermal conditions is shown in Table 4. The correlation coefficient isrelatively high (0.54 ~ 0.65) in the lower parts of the urban area (0.5 ~ 20m), but decreases above that height. The correlation between wind velocities
under isothermal and non-isothermal conditions is illustrated in Figure 11.
The linear equation, which is obtained from the regression analysis, isshown as Equation 2.
V=0.685Vi+0.657 (n=238,602, r=0.82, p<0.001)(2)

where, V is the wind velocity under non-isothermal conditions, Vi is thewind velocity under isothermal conditions, n is the number of meshes, r isthe correlation coefficient, and p is the significant level of correlation
coefficient or regression coefficient. The correlation coefficient is high(r=0.82) and the equation is statistically highly significant (p<0.001). If weknow the wind velocity under isothermal conditions from a similar model orthe calculation conditions of this research, the wind velocity under nonisothermal condition can be predicted using Equation 2.
As we explained above, it is confirmed that significant differences
exist in wind velocities under isothermal and non-isothermal conditions.
The wind velocity under non-isothermal conditions can be considered more
realistic because it considers the actual thermal environment of the urban
block. Thus, if the Bulk Richardson number is large, it is desirable toperform a CFD simulation under non-isothermal conditions to evaluate thewind environment. However, further research may be required usingparametric studies or wind tunnel experiments for fully acceptableconclusions.
4. CONCLUSION
In order to evaluate the wind environment of an actual urban block,numerical simulations of the thermal and wind environments wereconducted, and the following results were obtained for the differences underisothermal and non-isothermal conditions.
1. The wind velocity under non-isothermal conditions is higher than underisothermal conditions. The wind velocity under non-isothermal conditions ismore realistic considering the actual thermal environment of the urban block.
Thus, if the Bulk Richardson number is large, a CFD simulation is required
under non-isothermal conditions to evaluate the wind environment forbuilding design.

436

New Technologies for Urban Safety of Mega Cities in Asia

2. By using the proposed equation, the wind velocity under non-isothermal
conditions can be predicted from the wind velocity under isothermal
conditions.
3. The air temperature around the river is 0.5K lower than the urban area. It
was confirmed that the cool air flows from the river into the urban areas.
4. The heat is likely to diffuse in open spaces (wide streets, open land) andthus air temperatures are comparatively lower in such spaces. Conversely,
the heat is likely to accumulate in the densest areas (alleys, narrow spaces)
and thus the air temperature is highest in such areas. These phenomena arealso confirmed by the high correlation between air temperature and windvelocity.
REFERENCES
Hu, C. and Wang, F., 2005. Using a CFD approach for the study of streetlevel winds in a built-up area, Building and Environment 40, 617-631.
Huang, H., Ooka, R. and Kato, S., 2005. Urban thermal environment
measurements and numerical simulation for an actual complex urban area
covering a large district heating and cooling system in summer, Atmospheric
Environment 39, 34, 6362-6375.
Huang, H., Ooka, R., Chen, H., Kato, S., 2008. CFD analysis on trafficinduced air pollutant dispersion under non-isothermal condition in acomplex urban area in winter, Journal of Wind Engineering and Industrial
Aerodynamics, 96, 1774-1788.
Ooka, R., Chen, H., Huang, H. and Nakashima, M., 2006, Study on impact
factor index of buildings on outdoor thermal environment using coupledsimulation of convection, radiation and conduction, Proceedings of 19th
National Symposium on Wind Engineering 91-96.
Yoshida, S., Murakami, S. Mochida, A., Ooka, R. Tominaga, Y. and Kim,
S., 2000. Influence of green area ratio on outdoor thermal environment withcoupled simulation of convection, radiation and moisture transport, J. Archit.
Plann. Environ. Eng., AIJ, 529, 77-84.

Influence of Thermal Condition on The Wind Environment Evaluation for Building Design

437

EMERGENCY MANAGEMENT IN KOREA:JUST STARTED, BUT RAPIDLY EVOLVING 1
Kyoo-Man HA
Senior Researcher (Ph.D. & CEM), the National Institute for Disaster
Prevention, Korea
kyooha@nema.go.kr

ABSTRACTThe purpose of this paper is to examine emergency management in
Korea, with the ultimate goal of contributing to its development. Thus, thepaper will carefully study three major factors in the area of Korean
emergency management, namely: 1) vulnerability, 2) organization, and 3)
challenges and opportunities. In conclusion, it has been observed that
Korea has begun to manage its emergency comprehensively, after
experiencing various dreadful emergencies. No single factor has
characterized the feature of this dynamic emergency management in Korea.
Rather, diverse factors play their own roles in formulating the complexity of
its emergency management.

1. INTRODUCTION
The fact that Korea is the “Land of the morning calm” is no longer true,
owing to the various emergency situations that have occurred in recent years.
When the Sampoong department store collapsed in 1995 and when a fire
accident took place at Daegu subway train in 2003 and killed many people,
the majority of Koreans thought that these incidents were a disgrace, or evena shame on Korea. As a result, Korea has begun to comprehensively
manage its emergency situations at the national level. Therefore, it isinteresting to review how Korea has dealt with emergency management.
The purpose of this paper is to examine emergency management in
Korea, with the ultimate goal of contributing to its development. Thus, thepaper will carefully study three major factors in the area of Korean
emergency management, such as 1) vulnerability, 2) organization, and 3)
challenges and opportunities. These three factors are prerequisite to study
one national emergency management system.
2. VULNERABILITY IN KOREA

1

This paper has been posted on the website of U.S. Emergency
Management Institute’s Comparative Emergency Management Book Project
since
May
2009.
RelatedURL
isfollowings:
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October 2009, Incheon, Korea

Vulnerability means many things to different people. Some may thinkvulnerability to be a certain negative aspect in a specific hazard or
emergency situation, while others consider it to be a broad problem in thefield of emergency management. In this study, vulnerability indicatessomething that is extremely susceptible or being exposed to an attack or
possible damage in the whole field of emergency management. Like anysociety, Korea has many negative aspects in emergency management withrespect to the series of emergency situations that occur throughout the year.
Among those negative aspects, one of the most vulnerable aspects is related
to the national culture.
Many Koreans are now willing to talk more seriously about theconsequences of emergencies than about the preconditions of disasters or
the preparedness level before the outbreak of these events. For example, inthe case of Daegu subway fire in 2003, very few people opted for safety ofthe subway in Korea before this accident. Despite the fact that there weremany problems with regard to the subway, such as non-availability ofplatform screen (or platform edge) door, lack of appropriate firefighting
equipment, use of non-fireproof material in the subway cabin, etc., mostpeople did not pay much attention to the safety of subway train and subway
station in particular, before the accident.
However, many began to seriously criticize the government’s failed
policy and pointed out the importance of safety in subway for a limited
period of time after the Daegu subway fire that resulted in the death of 192
people and injured many others (National Emergency Management Agencyof Korea 2009). Accordingly, the government tried to solve the related
problems, but it has not made significant progress yet. As the government
did not attempt to replace all non-fireproof materials in the subway train
owing to its high cost, there may be a possibility of fire accidents in the
future. In short, many Koreans have already forgotten the consequences ofthis emergency.
Similarly, Korea has emphasized the significance of the recovery
phase more than that of the other three phases, namely the prevention andmitigation phase, the preparedness phase, and the response phase in theemergency management process. Theoretically, each phase should be given
equal or at least similar importance in modern emergency management
process, considering that each phase has its own value for the ultimate
purpose of emergency management. Therefore, all the four phases require
equal efforts in emergency management process. However, through public
or private affairs, it has been revealed that the Korean society has invested
emergency personnel, funds, and other resources primarily for the recovery
phase (Ha & Ahn 2008-1).
For example, the National Emergency Management Agency (NEMA)of Korea, which is a single comprehensive agency on emergency
management field, had four sub-headquarters, namely the prevention andmitigation headquarters, the preparedness headquarters, the response
headquarters, and the recovery headquarters under its authorities. The
NEMA intends to emphasize the importance of each phase in its policy
process, but currently it provides more support to the recovery phase thanthe other three phases.

440

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There are many reasons to explain why the Koreans have considered
the result of emergency without equal emphasis to emergency preparedness.
For instance, Korea has nationally emphasized the importance of recovery
more profoundly than the other phases. One of the important reasons isrelated to the communications revolution in the Korean society. As a resultof the development of many cutting-edge information channels in Korea,
such as high-definition TV, Internet, and mobile phones, breaking news canspread very quickly. In other words, because of expanded information,
people have an increased tendency to consider what has just happened suchas the outbreak of emergency, but they forget what happened before theevent, such as the poor level of emergency preparedness.
Besides the communication revolution, another reason forvulnerability is that for a long time, many Koreans used to consider
emergency as a sort of destiny. As controlling emergency was beyond theability of humans, many Koreans believed in the supremacy of hazards forseveral years. For instance, Koreans used to treat flood with typhoon as anannual activity, rather than trying to figure out how to prepare for it. Thus,
this kind of emergency awareness under a unique environment has partiallyencouraged the Koreans to seriously discuss the results of emergency.

3. ORGANIZATION OF EMERGENCY MANAGEMENT
In the field of Korean emergency management, public organization has
historically dominated the relationship with the private organization. A
popular thought has been that emergency management is a sort of public
goods. Also, the unitary government system has been developed thatconsists of three-level governments, such as the central government (similar
to the U.S. federal-level government), the province and the metropolitan
government (similar to the U.S. state-level government), and the local
government. When compared with the federal government system, lowerlevel governments in Korea have had less autonomy.
The central government established the National Emergency
Management Agency (NEMA) of Korea in June 2004 to startcomprehensive emergency management, though it was not completed. In
viewpoint of comprehensiveness, the NEMA has not been substantiallysuccessful. Before the establishment of NEMA, several institutions used to
manage their own special emergency area. Now, the NEMA, under the
Ministry of Public Administration and Security (MOPAS), has substantially
focused on managing both firefighting and civil engineering. The MOPAS
recently tried to setup its own policy area by giving more emphasis to thefunction of policy decision than the NEMA.
Lower-level governments, such as the provincial government, themetropolitan government, and the local government, have set up their own“Section of Emergency Management” in each institution, to primarily
handle flood with typhoon. Also, fire stations are located in each local
community to handle fire accidents. Furthermore, police stations in each
community play a major role in taking care of terrorism in Korea more thanother emergencies.

Emergency Management in Korea: Just Started, but Rapidly Evolving441

October 2009, Incheon, Korea

An increasing number of business corporations are setting up theirown business continuity plans (BCP) since the establishment of NEMA in
2004. In particular, the export-oriented corporations have expanded their
BCP activity because they may find it difficult to work on international
affairs without implementing their own BCP, according to the agreementwith World Trade Organization. The governments have also tried to help
them to establish BCP by passing a related act, which is the “Act on
Government’s Helping Business Corporations to Voluntarily Set Up theirBCP.” However, small- and medium-sized corporations have worked for
BCP, mainly by setting up their computer backup systems.
Voluntarism without being paid has not historically been a popular
activity in Korea, although its activity has recently increased. However, thevirtue of cooperation has been very popular by giving and taking diverse
forms of assistance during emergency. To elaborate, cooperation entails areciprocal exchange of service. However, when a person helps another, heor she assumes that they will return the favor at a later time in Korea (Ha &Ahn, 2008).
There are not many professional voluntary organizations in Korea.
Instead, community-based organizations (CBOs) have played diverse rolesin emergency management, which include the Young Men Group, theMarried Women Group, etc. To boost voluntary activity, the NEMA, as agovernment institution, has participated in voluntary organizations as theirmembers, which include the Korean Disaster Safety Network (KDSN) andthe Citizen Corps Active in Disaster (CCAD).
Residents and their community have to deal with emergencies more
directly than anyone else. Since the establishment of NEMA, many
residents have increased their awareness of disasters and emergency
management, although there is still room for improvement. When an
emergency receives national attention via mass media or Internet, awarenessamong residents and their community dramatically increases. However, amajority of the residents have not attempted to set up their own written
emergency operation plan (EOP), though some have done it verbally (Ha &Ahn 2009).

4. CHALLENGES AND OPPORTUNITIES
Korea faces numerous challenges in emergency management. For instance,
serious challenges include the national culture of giving importance to theconsequences of emergencies, lack of emergency awareness, unpopularityof voluntary activity, and so on. In this section, one of the biggest
challenges in Korea is examined.
The Korean government has mainly focused on managing both
firefighting and civil engineering, though they have officially claimed thatthe government policy has made or will make efforts to manage all kinds ofemergency. For example, civil engineering is related to flood from typhoons.
As a result, government policy has been substantially oriented towards those
two disasters, without any significant emphasis on other types of
emergencies. To make matters worse, two categories of emergency

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New Technologies for Urban Safety of Mega Cities in Asia

personnel have been major players in the field—firefighters and civilengineers. Some critics state that these two categories might dominate thefield of emergency management without incorporating other professionals.
As floods from typhoons hit the Korean peninsula annually, it is nowonder that the nation has focused on civil engineering. Similarly, as fire
accidents have dramatically increased in the society, it is needless to say that
firefighting is heavily emphasized. However, neither firefighting nor civilengineering can accomplish its own purpose without the help from otherspecialties, such as medical science, psychology, sociology, public
administration, law, military science, meteorology, other engineering, etc.
Emergencies including fire, flood, and typhoon, are very complicated innature or have multiple facets, and hence, they should be comprehensively
managed. In short, Korea may face much more difficulties in accomplishing
the goal of emergency management in the near future, as long as it focuseson two kinds of emergencies only.
There are many opportunities in Korea, depending on the individual’s
viewpoint. One of the most appealing opportunities is that Korea has started
to practice the modern concept of emergency management at the
government level, and even nationally. For example, Korea has initiatedemergency management at the central government level via four scientificsteps that include prevention and mitigation, preparedness, response, andrecovery. In Korea, a popular belief is that human beings would have theirown destiny. Hence, people accepted emergencies in their lives, rather thandaring to challenge them. Without doing anything significant, Koreans used
to stay at home and then just wait for the moment of being hit by natural
disaster or other emergencies.
However, many terrible emergencies, such as typhoons, floods, andsubway-train fires, took place in Korea at the beginning of the twenty-first
century, and numerous innocent people became victims. The angry public
strongly asked their government to take significant action to curb thoseemergencies. As a result, the governments established the National
Emergency Management Agency (NEMA) of Korea in June 2004. This is asingle comprehensive agency, which began to take charge of emergency
management in Korea. Further, the governments passed “the Basic Act on
Emergency and Safety Management,” incorporating a number of previous
laws and regulations. At the same time, the governments are willing toaccept the principles of modern emergency management by allowing
stakeholders to study about it in advanced countries, such as the U.S., Japan,and Australia.
Although the field of emergency management has been surrounded bymany difficult challenges, the fact that Korea has already started to utilize
the modern emergency management system is a very positive signal to thenation. It would be almost difficult to exactly predict the future of
emergency management. However, based on the modern concept ofemergency management, Korea is predicted to make every effort to solve
serious problems in this field.

Emergency Management in Korea: Just Started, but Rapidly Evolving443

October 2009, Incheon, Korea

5. CONCLUSIONSThis paper has reviewed the emergency management system in Korea
using three key factors. In short, it has been observed that Korea has begun
to manage its emergency comprehensively, after experiencing various
dreadful emergencies. No single factor has characterized the feature of thisdynamic emergency management in Korea. Rather, diverse factors playtheir own roles in formulating the complexity of its emergency management.
Based on the results of this research, many in the international
community as well as in Korea are expected to have a better understanding
about the process of Korean emergency management. The result of thisresearch, including both positive and negative aspects of Korea, is assumed
to contribute to the development of emergency management in other nations.
Furthermore, the results of this research are expected to increase the interestof many international scholars in comparing their ways of emergency
management with those of Korea.

REFERENCES
Ha, Kyoo-Man. 2009. Emergency Management in Korea: Just Started, but
Rapidly Evolving. Comparative Emergency Management Book Project.
Available at
http://training.fema.gov/EMIWeb/edu/CompEmMgmtBookProject.asp
Accessed on August 1, 2009.
Ha, Kyoo-Man & Ahn, Ji-Young. 2008-1. Developing voluntary agencies inemergency management: The United States and Korea. Journal of
Emergency Management. 6(4): 39-50.
Ha, Kyoo-Man & Ahn, Ji-Young. 2008-2. “National emergency
management systems: The United States and Korea.” Journal of Emergency
Management 6(2): 31-44.
Ha, Kyoo-Man & Ahn, Ji-Young. 2009. Local emergency management
systems in the U.S. and Korea. Unpublished Manuscript.
Ministry of Public Administration and Security. 1995. Past 30 Year History
on Emergency: 1963-1993 (written in Korean). Seoul.
Ministry of Public Administration and Security. 2002. Past 6 Year History
on Emergency (written in Korean). Seoul.
National Emergency Management Agency of Korea. 2007. Annual Reporton Emergency in 2007 (written in Korean). Seoul.
National Emergency Management Agency of Korea. 2009. NEMA Website.
Available at http://eng.nema.go.kr/ (Search date: February 20, 2009).

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CRITICAL REVIEW OF
THE STANDING ORDERS ON
DISASTER MANAGEMENT, BANGLADESH
MEHEDI AHMED ANSARY and RIPON HORE
Department of Civil Engineering, BUET, Bangladesh
ansary@ce.buet.ac.bd

ABSTRACTThe Standing Orders (SoD) on Disaster Management on Bangladesh
have been prepared with the objective of making the concerned persons
understand their duties and responsibilities regarding disaster management
at all levels. All Ministries, Divisions/Departments and Agencies shallprepare their own Action Plans in respect of their responsibilities under theStanding Orders for efficient implementation. According to the SoD, theNational Disaster Management Council (NDMC) and Inter-Ministerial
Disaster Management Coordination Committee (IMDMCC) will ensure
coordination of disaster related activities at the National level. The Disaster
Management Bureau will render all assistance to them by facilitating theprocess. The Ministries, Divisions/Departments and Agencies will organize
proper training of their officers and staff employed at District, Thana,
Union and village levels according to their own Action plans so that they
can help in rescue, evacuation and relief work at different stages of disaster.
The different activities of different organizations are described at different
Phase namely, Normal Phase, Alert and Warning Phase, Disaster Phase
and Recovery Phase.
Although SoD is there, the disaster preparedness and management
operations of the country lacks in activity and long term plans during
normal times as well as the implementation of the action plans taken after
recovery of a disaster. This is the basic reason behind the huge damages
and losses of properties as well as significant number of the death tollcaused by Disasters. In some cases, overlapping of the different activities
among the different organizations created a huge problem. On the other
hand, the SoD is not properly followed by the different organizations. The
SoD lacks structural solution/mitigation which is sometimes required in the
pre-disaster as well as post-disaster cases. The coordination between theinternational and national agencies is not clearly defined in the SoD. The
SoD itself needs modification and clarifications of the roles of personnel
and organizations. This paper tries to summarize different salient featuresof the SoD and prescribe modifications which will improve the disastermanagement system in Bangladesh.

445

October 2009, Incheon, Korea

1. INTRODUCTION
Bangladesh is the largest delta in the world situated at the northern fringe ofthe tropics. The country is the worst victim of natural disasters through theprevailing weather systems during pre- and post- monsoon, causing at times
huge loss of lives and damage to properties, and also the sufferings anddisplacement of affected population. Natural and human induced hazards
such as floods, cyclones, droughts, storm surges, tornadoes, earthquakes,
riverbank erosion, fire, infrastructure collapse, the high arsenic contents ofground water, water logging, water and soil salinity, epidemic and various
forms of pollution are frequent occurrences. Over the years, Bangladesh hasdeveloped a system of disaster management. But in the system the focus ofdisaster management has been relief and rehabilitation.
The standing orders on disaster outlines the disaster management
arrangements in Bangladesh and describes the detailed roles andresponsibilities of committees, Ministries, Departments and other
Organizations involved in disaster risk reduction and emergency responsemanagement and establishes the necessary actions required in implementing
Bangladesh’s Disaster Management Model.
A Bangladesh Network Office for Urban Safety (BNUS) team has visitedthe cyclone SIDR affected areas from May 4 to 11, 2008. They have met
different professionals from Government and NGO sectors and some
affected population and compiled a report on cyclone SIDR. In this paper,
the activities of the different organizations according to the SoD have been
analyzed with respect to Draft-Sidr Report (CDMP, 2008) and BNUS
Report. Aslo the activities of the different organizations of two worst
affected districts Patuakhali and Barguna due to cyclone SIDR have been
analyzed.
2. ORGANIZATIONS INVOLVED
The different organizations involved during cyclone SIDR as reported by
CDMP (2008) is listed below:• Meteorological Department• Public Health Engineering Directorate (DPHE)• Local Government Engineering Department (LGED• Bangladesh Water Development Board (BWDB)• Bangladesh Inland Water Transport Authority (BIWTA)• Ministry of Education (MOE)• Ministry of Fisheries and Livestock (MOFL)• Directorate of Fisheries• Ministry of Environment and Forestry (MOEF)
The different organizations whose activities are analyzed by BNUS team are
as follows:• Armed Forces Division (AFD)446

New Technologies for Urban Safety of Mega Cities in Asia

•
•
•
•
•
•
•

Deputy Commissioner (DC)District Relief and Rehabilitation Officers (DRRO)
Field Office of Executive Engineer of BWDB
Upazila Nirbahi Officer (UNO)
Field level CPD Officials
Bangladesh Red Crescent Society Officials
Field Office of Executive Engineer of LGED

3. FEATURES OF THE EXISTING SOD
The existing SoD has Normal Phase, Alert and Warning Phase, Disaster
Phase and Recovery Phase. A short definition of the phases are provided
below:
Normal Phase (Normal Time):
A period when there is no immediate threat but long-term actions are
required in anticipation of the impact, at some unknown time in the future,of known hazards.
Alert and Warning Phase:
The period from the issuing of an alert or public warning of an imminent
disaster threat to its actual impact, or the passage of the threat and the liftingof the warning. The period during which pre-impact precautionary, ordisaster containment measures are taken.
Disaster Phase:
The period during which direct impact of a natural calamity is felt. Disaster
phase is long in case of slow on-set disasters (draughts, normal monsoon
flood) and short in case of rapid on-set disasters (flash flood, cyclone,earthquake, fire, industrial accident, landslide etc).
Recovery Phase:
The period, following the emergency phase, during which actions are to betaken to enable victims to resume normal lives and means of livelihood, andto restore infrastructure, services and the economy in a manner appropriate
to long-term needs and defined development objectives.
The existing SoD is divided in to following parts:
Part 1: introduction, part 2: national policy and coordination, part 3: local
level coordination, part 4: roles and responsibilities, part 5: other matters.
Also in the SoD, Overlapping of the different activities among the different
organizations can be observed; No structural solution is provided; The SoD
Mainly focusing on the post disaster stages.

4. ACTIVITIES OF THE DIFFERENT ORGANIZATION DURING
SIDR

Critical Review of The Standing Orders on Disaster Management, Bangladesh

447

October 2009, Incheon, Korea

Different organizations obey the SoD rules mainly during Disaster andRehabilitation Stages. Armed Forces Division (AFD) of Bangladesh playeda significant role in SIDR Management. AFD involved its own workforce
and logistics in damage assessment and relief and rehabilitation activities.
They immediately launched a massive search and rescue operation and also
assisted in the burial of dead bodies and removal of debris and dead
livestock. AFD were not only maintained the standing order for disastermanagement (SoD) but also provided some additional services. The
activities of the LGED are not clearly defined in the SoD. During SIDR,
LGED assisted AFD. “Ensure effective training and orientation of thevolunteers, formed for cyclone preparedness programmer drawn through
CPP and other agencies”, “Arrange tree plantation at shelter places forprotection against the severity of tidal bore due to flood and cyclone andarrange proper maintenance of ponds, village roads, embankments andsluice gates”, these are the activities of the Deputy Commissioner (DC) who
are incharge of the districts. In reality, no such activities are performed(BNUS, 2008; CDMP, 2008). The activities are maintained by therespective authorities such as BDRCS, few local NGOs, LGED, and WDB
etc. The activities between of Cyclone Preparedness Program (CPP) and
Bangladesh Red Crescent Society (BDRCS) are sometimes overlapped. The
number of different activities followed by different organization during
SIDR is shown in Figure 1.
Figure 2 shows theiractivities according to
SoD.
7

6

Number of Activity

5

4

3
AFD
MEOEF
DOF
MOFL
MOE
BIWTA
BWDB
LGED
DPHE
at
io

n

2

O

rg
an
iz

1

448

Disaster

BMD
Rehabilitation

Time

Alert & Warning

Normal0

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1: Activity Checklist for different organizations during SIDR

1098

Number of Activity

7
6
5
4
MEOEF

3

MOFL
2

Disaster

BMD
Rehabilitation

Time

Alert & Warning

Normal

0

O

rg
an
i

LGED

za
tio
n

BIWTA
1

Figure 2: Activity checklist for different organizations according to SoD
Figures 3 and 4 show activity checklist of different field level offices during
SIDR and in SoD, respectively.

5. PROPOSED MODIFICATIONS IN THE EXISTING SOD
The Disaster Stage of the Meteorological Department is not mentioned in
SoD. The SoD needs some modification and mention the role of the
Bangladesh Meteorological Department (BMD) during the disaster stage
clearly. The roles of BMD during the disaster stage in SoD may be as
follows:• Continuously monitoring the weather condition and supply information
through Fax/telephone/teleprinter to the Ministry of Food and Disaster
Management (MOFDM) and other concerned organizations.
• Monitoring the position of the cyclone, speed, direction and supply
information through Fax/telephone/teleprinter to the Ministry of Foodand Disaster Management (MOFDM) and other concerned organizations.

Critical Review of The Standing Orders on Disaster Management, Bangladesh449

October 2009, Incheon, Korea

During normal time, the awareness about the SoD needs to be createdamong the administration level and the related personnel. The structural
solutions for different disasters need to be included within SoD and actions
to be carried out by the relevant organizations should be mentioned.
An advisory committee must be established under the Ministry of Food andDisaster Management (MOFDM) to monitor the different stages of SoD andprovide advice for the Minister of MOFDM for immediate actions just aftera disaster takes place. Local contingency plans must be prepared by national
level and field level organizations to cope during a disaster event.
Research center must be built with skill persons and a continuous researchneeds to be carried out for better management and engineering solution ofdisaster problems. The coordination between the different foreign and localorganization during the post disaster situation must be defined in the SoD. A
time frame may be established to activate the different activities.

12

Number of Activity

10

8

6

4

FOEE (LGED)
BDRCS
Field Level CPP

2

DisasterDC
Rehabilitation

Time

Alert & Warning

Normal

O

rg
a

DRRO

0

ni
za
t

FOEE (BWDB)

io
n

UNO

Figure 3: Activity checklist for different field level organizations
during SIDR
6. CONCLUSIONS

450

New Technologies for Urban Safety of Mega Cities in Asia

Bangladesh has got a well organized network for cyclone early warning
system and preparedness at all stages which contributed significantly in
reducing human causalities due to several recent cyclones Still the disaster
preparedness and management operations of the country lacks in activity
and long term plans during normal times as well as the implementation of
the action plans taken after recovery from a disaster. This is the basic reason
behind the huge damages and losses of properties as well as significant
number of the death caused by a disaster in Bangladesh. The existing SoD
also needs some modification and clarifications of the roles of personnel andorganizations as mentioned in the paper. The authors hope that theGovernment of Bangladesh need to take necessary steps to overcome thissituation. With proper planning pre-disaster and post disaster situation canbe better managed.

25

Number of Activity

20

15

10
FOEE (LGED)
BDRCS
Field Level CPP

5

rg
an
iz
at
io

Rehabilitation

Disaster

Alert & Warning

Normal
Time

DC

O

DRRO

0

n

UNO
FOEE (BWDB)

Figure 4: Activity checklist for different field level organizations
according to SoD

REFERENCES:
BNUS (2008). Report on Cyclone SIDR, BUET, Dhaka.
CDMP (2008). DRAFT Report on Cyclone SIDR in Bangladesh, Damage,
Loss and Needs Assessment for Disaster Recovery and Reconstruction.
Government of People’s Republic of Bangladesh (1999). Standing Order on
Disasters.
World Bank Report (2008). Cyclone SIDR in Bangladesh, April, 2008.

Critical Review of The Standing Orders on Disaster Management, Bangladesh451

October 2009, Incheon, Korea

452

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 7SEISMIC PERFORMANCE OF
REINFORCED CONCRETE STRUCTURESHIROSHI SHIMA
Kochi University of Technology, Japan
shima.hiroshi@kochi-tech.ac.jp

ABSTRACTReinforced concrete is ductile when design and construction isproperly so that it should be suitable for mega cities not only without
earthquake but also with frequent earthquakes. Seismic design code inJapan has been revised sometimes based on experiences of past earthquake
damages. Performance-based seismic design code for civil structures inJapan was published in 1996 just after 1995 Hyogo-ken Nanbu Earthquake.
Seismic performance required to reinforced concrete structures for civil
structures and method for verification of the performance of structures aredescribed in this paper.

1. INTRODUCTION
One of causes of disaster in mega cities in Asia is earthquake. Concrete
structures have been damaged by large scale earthquakes. The number ofconcrete structures in a mega city is going to increase with the degree ofdevelopment. Normally, reinforced concrete is ductile if it is designed andconstructed properly. The reinforced concrete should be suitable structure
system for the mega cities in Asia especially with frequent earthquakes.
Japan is one of countries which are subjected to large scale earthquakes
frequently. Design code for the reinforced concrete structures in Japan was

Photo 1: A seismic damage at Kobe City in 1995

453

October 2009, Incheon, Korea

published firstly in 1933. Calculation method for seismic design was
proposed in this code. The number of the concrete structures in Japan
increases with economic growth since that time. However, not a few
concrete structures have been damaged by every large scale earthquakes.
Seismic design code has been revised sometimes based on these experiences.
Hyogo-ken Nanbu Earthquake in 1995 was the most disastrous earthquake
at a mega city on record that had ever been experienced after the reinforced
concrete structures came popular in Japan as shown in Photo 1. The seismic
design code was revised to performance-based design method with theexperience of this earthquake. In this paper, the seismic performancerequired to reinforced concrete structures for civil structures and theverification method for the seismic performance are described.

2. SEISMIC DESIGN CODES FOR CONCRETE STRUCTURES IN
JAPANSeveral specifications or guidelines of seismic design for concrete structures
have been issued from different organizations in Japan, such as Japan
Society of Civil Engineers (JSCE) for civil structures, Architectural Instituteof Japan (AIJ) for buildings and Japan Road Association.
Codes of seismic design for reinforced concrete structures are going tochange to be performance-based type. For example, JSCE published a codefor seismic design in Standard Specification for Concrete Structures after
one year of Hyogo-ken Nanbu Earthquake in 1995. This part of seismic
design prescribed how to verify the seismic performances in advance of theother parts of the specifications. The latest seismic design method is
described in Chapter 11 ‘Seismic Performance Verification’ in “Standard
Specifications for Concrete Structures-2007, Design” (JSCE, 2007) .

3. CONCEPT OF DESIGN METHOD
Definition of terms “Design” and “Verification”, especially definition of“Design” is not always clear. “Verification” is the step in which checks thata given structure satisfies the required performance to the structure or not.
“Design” in narrow sense means to create or set up type of structure, shapeand dimensions, materials, details of cross section and so on for the previous
step of the verification. “Design” in wide sense is a total system to decidestructure from type to details including the step of verification.
The concept of the performance-based design method is to decide theperformance required to the structure and verify that the given structure
satisfies the required performance. However, in most cases, the required
performance is conceptual so that the technique to verify the required454

New Technologies for Urban Safety of Mega Cities in Asia

performance directly has not been developed yet. For example, JSCE
Standard Specifications define the seismic performance as follows.
In general, seismic performance level of a structure may be classified
into the following three levels.
(i) Seismic Performance 1 : Function of the structure during anearthquake is maintained, and the structure is functional and usable
without any repair after the earthquake.
(ii) Seismic Performance 2 : Function of the structure can be restored
within a short period after an earthquake and no strengthening isrequired.
(iii) Seismic Performance 3 : There is no overall collapse of thestructural system due to an earthquake.
However, it is impossible to verify above performances numerically underpresent condition. In order to make verification, designers prescribe thelimit state which can guarantee these performances and replace theperformance verification with the examination of limit state as shown in
Figure 1. At the examination of limit state, the index which represents thestate is selected and limit value according to the required performance isgiven. Namely, seismic performance verification of a structure is carriedout by confirming that calculated response value (Sd) under assumed
earthquake ground motion does not exceed limit value (Rd) using specified
safety factors  as given in Eqs.(1) to (3).
 i S d / R d  1 .0

(1)

S d   a S(2)

R d  R /  b(3)

Seismic structural planning
Designation of Seismic performance
Ground motion

Seismic performance

Response analysis

Limit state

Verification index
Limit value R

Response value S
S / R 1.0

Figure 1: Flow of seismic performance verification

Seismic Performance of Reinforced Concrete Structures455

October 2009, Incheon, Korea

4. DESIGNATION OF SEISMIC PERFORMANCE
Seismic forces which are supposed to act to a structure in its service lifetime
vary from small to big. Therefore, the seismic design of structures should
be done to have designated seismic performance against to supposed
earthquake ground motions. For example, the requirement is such that “astructure does not need any treatment after medium scale earthquake which
occurs sometimes and is not destroyed by large scale earthquake which
occurs with low probability”. When a structure is designed only to not be
destroyed by large scale earthquake, the required performance for no
damage to medium scale earthquake has possibility to be satisfied.
However, this fact is not generally truth. In general, the seismic
performance should be designated to some various scales of earthquake
ground motion.
Concerning on the earthquake ground motion supposed in design work, JSCE
Specification suggests the following two levels of earthquake ground motion.
In general, two kinds of design earthquake ground motions – Level 1 andLevel 2 as given below, may be considered.
(i) Level 1 Design Earthquake Ground Motion: earthquake groundmotion that is likely to occur a few times within the lifetime of astructure.
(ii) Level 2 Design Earthquake Ground Motion: very strong earthquake
ground motion that has only a rare probability of occurrence within
the lifetime of a structure.
Seismic performance required to a structure is necessary to be designatedwith corresponding to level and return period of earthquake ground motion.
In JSCE Specification, the relationship between the assumed ground motion
and required seismic performance is described as follows.
In general, the following verification may be carried out.
(i) The structure satisfies Performance 1 against Level 1 Earthquake
Ground Motion.
(ii) The structure satisfies Performance 2 or 3 against Level 2
Earthquake Ground Motion.

5. DESIGNATION OF LIMIT STATE AND LIMIT VALUE
In case of verification on seismic performance of structures, it is necessary to
decide the limit state from which the seismic performance comes to beunsatisfied correspondingly with each designated seismic performance. The
seismic performance is, in general, designated as a performance to the structure.
The limit state corresponding to the performance of structure should be456

New Technologies for Urban Safety of Mega Cities in Asia

designated also as a limit state of the structure. However, the relationshipbetween the damage of structure level and damage of member level is mostly
not clear. On the other hand, the verification techniques for the limit state ofmember level have been advanced. Therefore, it is general that the limit state isdesignated to the member or element composing structure.
A way of approaching the limit values corresponding to each seismic
performance in JSCE are described below.
5.1 Seismic Performance 1
Concerning on the performance “Function of the structure during anearthquake is maintained”, when it is necessary that safety of moving
vehicles should be examined, the maximum response displacement should
be defined as the limit value.
The performance “The structure is functional and usable without any
repair after the earthquake” can be satisfied unless re-bars yield. Therefore,
yield displacement of a member can be decided as the limit value of Seismic
Performance 1 on the assumption that members do not fail in shear. Before
yielding of re-bars, stress of concrete does not reach the compressive
strength. However, when reinforcement ratio is large, it may be necessarythat the compressive strength is defined as the limit value.
5.2 Seismic Performance 2
The performance “Function of the structure can be restored within ashort period after an earthquake and no strengthening is required” can not besatisfied if members fail in shear or torsion. Therefore, shear and torsional
capacity of a member become to the limit value.
On the other hand, when members do not fail in shear or torsion, it
becomes a problem that how to represent the degree of damage corresponding
to the performance “Function of the structure can be restored within a shortperiod after an earthquake and no strengthening is required”. Loaddisplacement relationship of a member is closely related with the degree ofdamage as shown in Figure 2 (Watanabe et.al., 2001). For example, it was
found that buckling of longitudinal bars associated with spalling of concrete
cover causes drop of flexural capacity in flexural failure type column. Fromthese information, the performance “Function of the structure can be restored
within a short period after an earthquake and no strengthening is required”
when members do not fail in shear or torsion can be confirmed by checking the
maximum response displacement of the member. JSCE Specification defines
the ultimate displacement as one of the limit values for Seismic Performance 2.
In some structures, there may happen troubles in reusing them, when theresidual displacement becomes remarkably large. In those cases, the residual
displacement may be defined as the limit value which is determined considering
time and cost necessary for restoration and expected residual functions.

Seismic Performance of Reinforced Concrete Structures

457

October 2009, Incheon, Korea

Figure 2: Relationship between load-displacement curve and damagelevel of a column (Watanabe et.al.,2001)
5.3 Seismic Performance 3
The technology to verify the performance “There is no overall collapseof the structural system due to an earthquake” is developing. In general, thisperformance is satisfied when vertical members do not crush in verticaldirection. This kind of collapse can be normally prevented when the member
is sufficiently safe against shear failure. However, in the case of high axial
force, column collapses due to reversed loading after longitudinal bars yieldeven if shear failure does not occur. It is found that downward displacementof a column increases with repetition of loading from Figure 3.
In some cases, however, displacement of the whole structure becomes
excessive, and additional bending moment as well as longitudinal
displacement of member increase due to self-weight. These sometime maylead to self-collapse. Therefore, it should be necessary to confirm using the
response analysis of structures during earthquake that the structure does notreach to the condition of self-collapse due to self-weight.
200
100

5

Vertical displacement (mm)Horizontal force (kN)300
a/d=3.6
n=3.1N/mm 20-100
Step 3720-200

Step 3886

-300
-72

-48
-24
0
24
48
Horizontal displacement (mm)

72

0

-5

a/d=3.6

Step 3720

n=3.1N/mm 2

Step 3886

-10
-72

-48

-24

0

24

48

72

Horizontal displacement (mm)Figure 3: Horizontal force and vertical displacement under reversed cyclicloading of column (B400D400, H=1350mm, N=500kN)

458

New Technologies for Urban Safety of Mega Cities in Asia

6. CALCULATION OF RESPONSE VALUE
The response value caused by assumed earthquake motion is calculated
correspondingly with the limit value.
6.1 Analytical method
There are several analytical methods to calculate the response value.
Typical examples are static analysis, quasi-dynamic analysis such as
response spectrum method and time history response analysis. Recently, thenumerical simulation technique has been developed notably and reliabilityof analytical results has also been improved sufficiently throughcomparisons with several kinds of experimental results. The time history
response analysis is the most rational to analyze overall structure system
including surrounding ground. JSCE Specification describes that the
response should be estimated by carrying out the time history response
analysis for the estimation of response values.
6.2 Representation of ground motion
Representation method of ground motion is different with analyticalmethod. A design seismic coefficient is used in the static analysis and anelastic or nonlinear response spectrum is used in the quasi-dynamic analysis.
It is necessary to represent earthquake ground motion as a waveformin time history in order to execute the time history response analysis. The
waveform of ground motion can be represented in terms of displacement,
velocity and acceleration. The acceleration waveform is generally usedbecause of convenience in equation of motion. A sample of acceleration
waveform given in JSCE Specification is shown in Figure 4.
800600

ACC (gal)

400
200
0
-200
-400
-600
-800
0

5

10

15

20

25

30

35

40

Time (sec)Figure 4: An example of acceleration waveform given in JSCE Specification
6.3 Modeling of structure system and input point of earthquake motion
The seismic force which acts to a structure is affected by theproperties of subsurface ground at the location of the structure. Also, there
is an effect of interaction between structure and surrounding ground on theseismic response of structure. The combinations of types of structure andSeismic Performance of Reinforced Concrete Structures459

October 2009, Incheon, Korea

surrounding ground are infinite. A whole structural system including
foundation or surrounding ground should be analyzed in order to estimate
the effects of subsurface ground and its interaction properly. JSCE
Specification describes as follows.
(2) For the whole structure system, a coupled analysis considering thestructure and the ground together shall be carried out. However, if
dynamic interaction between the structure and the ground can beneglected or it can be appropriately modeled, the structure may beanalyzed independently.
An example of structure and ground in coupled analysis is shown in
Figure 5. Standard method to analyze the structure and the ground
independently is shown in Figure 6. The usual underground structure
constructed in the subsurface ground is hard to cause the relative vibration
against the ground. The structure follows the displacement and deformationof circumference ground during an earthquake, and the influence of inertia
force caused by the mass of structure is small. When the oscillation modeof the ground coincides with that of the structure, it can be used that the
deformation of the ground during the earthquake is obtained firstly and theresult is acted statically on the structure as forced displacement. Thismethod is called as response displacement method.

Figure 5: Example of structure and ground in coupled analysis

Base part ofEarthquake ground motion

Input toEngineering

Grounds

Earthquake ground motion

Figure 6: Method to analyze a structure independent of the ground460

New Technologies for Urban Safety of Mega Cities in Asia

6.4 Modeling of structures
In order to analyze the structural response, it is necessary to represent
structure by an appropriate structural model. As structure is composed ofmembers connected in three dimensions, strictly speaking, it may bemodeled in three dimensions. Two-dimensional modeling of structure,
however, may be applied in case that only response in two-dimensional
plane is enough to be considered according to the characteristics ofstructural response.
In modeling of structure, it is general to use two types of models: one
is finite element model and another is beam element model. The beam
element model represents column and beam by one line as shown in Figure
7. Applicable range is limited and quality of modeling affects to theaccuracy of analytical results. The finite element model represents
constituent members such as column, beam, wall and so on, as an assemblyof small elements as shown in Figure 8. This model can be applicable to thearbitrary shape of structures and members.

Figure 7: Beam element model

Figure 8: Finite element model

JSCE Specification defines the modeling of structures as follows.
(3) Structures should be modeled as 3-D or 2-D assembly of members.
(4) Structures should be analyzed using finite element or beam element
models.
6.5 Modeling of materials
Even in any structural modeling, it is necessary to model material
properties so that the structural properties can be reproduced. Stress-strain
relationship of constitutive materials is used in the finite element model andmoment-angle relationship at end of member is used in the beam element
model. These material models should be able to take nonlinear behavior
under reversed cyclic loading into account. In JSCE Specification describes
the details of analytical models of structure by finite elements as shown in
Figure 9, by lumped mass and beam element, and analytical models ofground as shown in Figure 10.

Seismic Performance of Reinforced Concrete Structures461

October 2009, Incheon, Korea(a) Concrete(b) Reinforcing bar
Figure 9: Hysteresis model of materials
G 0   a   a   a12 ryHysteresis curve(loading)

1
G0

1

G

 a ,  a 

skeleton



G 0
1

y

  a ,  a 

Hysteresis curve(unloading)  a r

G 0   a   a1
2 r

Figure 10: Dynamic shear stress-strain curve of soil

7. CONCLUSIONS
It is clear that reinforced concrete structure is indispensable to mega cities.
The reinforced concrete structures should maintain their functions during
and after an earthquake. The performance-based design method must be
suitable for facilities with a great wide variety of performance requirements
in mega cities. The technology for the performance-based seismic design isdeveloping. It is believed that progress of the technology to simulate theresponse of reinforced concrete structures against to an earthquake willcontribute to the urban safety of mega cities in Asia.

REFERENCES
JSCE, 2007. Standard Specifications for Concrete Structures-2007 ‘Design’,
Japan Society of Civil Engineers
Watanabe, T. et.al., 2001. Evaluation method of deformation capacity
related to damage conditions for reinforced concrete members, Journal ofmaterials, concrete structures and pavement, Japan Society of Civil
Engineers, No.683/V-52, pp.31-45, 2001.8

462

New Technologies for Urban Safety of Mega Cities in Asia

MODELING OF RC COLUMNWITH LAP SPLICES STRENGTHENEDBY FIBER REINFORCED POLYMER
DAM XUAN THAI
Sirindorn International Institute of Technology, Thammasat University, Thailand
AMORN PIMANMAS
Sirindorn International Institute of Technology, Thammasat University, Thailand

ABSTRACTThis paper presents a two-dimensional (2D) nonlinear analyticalmodel for analyzing reinforced concrete (RC) column with short lap splicestrengthened by fiber reinforced polymer (FPR) under seismic force. The
model was developed based on previous proposed nonlinear model, andapplied to simulate experiment studies on RC column with lap splicestrengthened by FRP sheets or prefabricated plates for verification. The
model is applicable to both rectangular and circular section, and to bothfull and partial wrapping. The model is divided into an elastic frame and an
assembly of nonlinear springs to represent the elastic portion and theplastic hinge, respectively. The effectiveness of FRP wrapping forstrengthening lap splice is taken into account by modifying properties ofnonlinear springs. Finally, the model was incorporated into Ruaumoko2D(Carr 1998) software for analyzing RC column strengthened by FRP
wrapping around lap splice zone.

1. INTRODUCTION
The critical non-seismic reinforcement details of sub-standard columns
which violate modern seismic design theory were identified. These include
short lap splices of column reinforcement located immediately above floor
levels or lap splice with starter bars from footing, widely spaced column ties,
inadequate hoop reinforcement in potential plastic hinge regions and joint.
Lap splice length designed for gravity only was normally shorter than that
required in current seismic design standards, thereby possibly aggravating
seismic performance of structure. The transfer of forces across the interface
between steel and concrete through bond plays a major role on the behaviorof reinforced concrete members. Cracking, deflections, structural strength,
energy absorption and dissipation capacities under seismic loading are all
related directly or indirectly to bond.
Several methods, such as external jacketing by steel plate, composite
materials, or steel fiber concrete, were used to strengthen lap splice capacity.
Some experiments and analytical models were conducted to assess the effect463

October 2009, Incheon, Korea

of strengthening lap splice on seismic resistance of column, and also toassess the effectiveness of each strengthening method on lap splice capacity
improvement.

Figure 1: RC column model, Matrin (2007)
Fiber reinforced polymer (FRP) composites have found increasingly wide
applications in civil engineering due to their high strength-to-weight ratio
and high corrosion resistance. One important application of FRP-composites
is as a confining material for concrete in the retrofit of existing reinforced
concrete (RC) columns. As a result of FRP confinement, the compressive
strength and the ultimate strain of concrete can be greatly enhanced. The
bond stress between reinforced bar and concrete is also increased.
Lowes et al. (2003) formulated a versatile two-dimensional macro-modelthat represents a reinforced concrete beam-column joint. In their model, thebond slip and shear deformation responses of joints were considered as
separate springs. The zero-length bond-slip springs were representatives ofthe force transferring ability between flexural reinforcement and thesurrounding concrete while the zero-length shear springs represented theability of shear transferring at the interface between frame members and thejoint.
Matrin (2007) developed a reinforced concrete column two-dimension
model (Figure 1) to simulate behavior of reinforced concrete column
without jacketing, subjected to seismic excitation. Basically, a singlecurvature column model consists of two major parts; the first part is anelastic frame oflength, which represents the elastic behavior ofcolumn. The second part consists of a zero-length fiber section which is an
assembly of nonlinear springs to represent the concrete and reinforcement
nonlinear behavior. The second part is connected to the first part by a rigid
link of464

length.

New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Discrete fiber section, Matrin (2007)
The fiber section was divided into a number of discrete fibers (Figure 2).
Each fiber will be modeled as concrete spring or steel spring, whosecharacteristics can be calculated from the section of fiber and material
properties. The concrete springs are classified into two types, confinedconcrete and unconfined concrete. The steel springs represent thereinforcement in each fiber (Figure 3). The steel spring normally consistingof three sub springs, i.e. steel bar sub-spring, lap splice spring, and bond-slip
spring connected in series from top of fiber. Shear behavior of column canbe simulated by a separate nonlinear shear spring.

Figure 3: Model a reinforced bar by 3 sub-springs
Ruaumoko2D is a well known platform for modeling reinforced concrete
structure, especially with capacity of degradation simulation and a huge
database of hysteresis model embedded in the program. Martin (2007) used
Ruaumoko2D to simulate cyclic behavior of several reinforced concrete
members, and found that the comparison between analytical model andexperimental result were closed. In this paper, the authors employed
Ruaumoko2D to simulate reinforced concrete column externally confined

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer465

October 2009, Incheon, Korea

by FRP sheet around the lap splice region. The nonlinear model of lap splicespring model with FRP confinement is incorporated into Ruaumoko2D. The
suitability of the nonlinear model is extensively verified via several
experiments conducted in the past.

2. NUMERICAL MODELING PARAMETERS
Various nonlinear parameters for modeling RC column strengthened by
FRP confinement are described here. Particular attention is paid to thenonlinear properties of lap splice spring with and without FRP wrapping.
2.1 Length of plastic hinge region
The length of plastic hinge ( ) is an essential parameter, which
separates a column into 2 parts, i.e., elastic (frame) and plastic (fiber
section) part. Priestley and Seible (1991) suggested the following plastic
hinge length formulas for analyzing inelastic flexural behaviors of
reinforced concrete columns with and without FRP jacketing:Without FRP jacketing(1)

With FRP jacketing(2)

is a gap at the bottom of the jacket;
and are diameter andwhere
yield strength of reinforced bar, respectively.
Xiao and Ma (1997) proposed an approach, in which the plastic hinge length
was assumed variable corresponding to the steel stress of the extreme tensilebar. The expressions (3) and (4) take the same format of (1) and (2) but

use variable steel stress, instead of the yield strength fy.

Without FRP jacketing(3)

With FRP jacketing(4)

2.2 Elastic frame element
Elastic-frame element is used to simulate flexural and axial stiffness inthe elastic part (top portion of the cantilever column). As recommended by; the effective
ATC-40 (1996), the effective flexural rigidity is set toaxial rigidity is set to; the effective shear stiffness is set to. Elastic
modulus of concrete

is set to

ACI318 (2005). In which,466

as recommended byis compressive strength of unconfined

New Technologies for Urban Safety of Mega Cities in Asia

concrete;andrespectively.

are gross area of section and the height of column,

2.3 Nonlinear Shear spring
Nonlinear shear spring is used to capture shear mechanism(deformation and stress) of column. Effective shear stiffness is set to
as adopted from ATC-40 (1996)
Shear strength of column with and without FRP wrapping can becalculated by equation (5) (Ye et al. (2002)).
(5)
In which

is shear strength of column without FRP wrapping obtained byequation (6), (Sezen (2002)).
is additional shear strength provided by
FRP sheets given by (7)-(9) ,Ye et al. (2002).

(6)
(7)
(8)

(9)
(10)

Lateral displacement (10) of gravity load collapse
is proposed by
Moehle et al. (2000). A monotonic curve that governs the behavior of shear
spring is shown in Figure 4, in whichis lateral force corresponding tostate of gravity load collapse and assumed equal to

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer.

467

October 2009, Incheon, Korea

Figure 4: Monotonic curve for nonlinear shear spring
2.4 Concrete spring
The peak compressive force of concrete springarea of concrete in a fiber
concrete(11) depends onand confined compressive strength ofwhich can be obtained from unconfined compressive strength

by multiplying with confinement factor

shown in Eq. (12).
(11)
(12)

Calculation of confinement factor
follows a uniaxial stress-strainmodel (13); (14) for confined concrete with either FRP or transverse
reinforcement as proposed by Harajli et al. (2006). The model is applicableto various conditions of cross section (rectangular and circular), wrapping
method (partial and full), thickness and number of FRP sheets, types of steel
stirrups (spiral and tie).
(13)

⎛

⎛f

⎝

⎝ fC

⎞⎞
⎟
⎠⎠

ε CC = ε 0 ⎜⎜1 + k2 ⎜⎜ CC' − 1⎟⎟ ⎟

(14)
(15)

The degradation of concrete spring is determined by a point ofremaining 50% peak stress with corresponding strain (15) (Roy and Sozen(1965)). A monotonic curve that governs the behavior of concrete spring(confined or unconfined) is shown in Figure 5.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 5: Monotonic curve for concrete spring
2.5 Bond slip sub-spring

A bi-linear bond-stress model proposed by Sezen and Moehle (2003)
is adopted. The anchored bar length was generally divided into two parts,
elastic

and plastic

zone with constant bond stresses

andrespectively. The length of elastic zone is given as
lengthofplastic

is

zone

to

(if

set

equal

, the plastic zone

depends on the state of stress in the anchorage zone.

For tension and compression zone,
and, while the). When the stressis less than yield strength
acting on steel bar
disappears, the anchorage behavior is purely elastic.
Plastic bond stress,(Shima et al. (1987))(Lowes et al. (2003)), respectively. Elastic bond stresscan be approximately estimated by, in which the required length

is recommended by ACI318 (2005) for tension (16) and compression(17) zone.
(16)
(17)
The critical force at bond failure can be obtained by trial procedure, inwhich the stress of bar will be increased until the satisfactionof. Fig 6 shows two types of bond failures, before and after

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer469

October 2009, Incheon, Korea

bar yielding depending on the anchorage length. The bond-slip can be.

computed as

Fig 6: Monotonic curve governs bond and lap splice spring

Steel bar sub-springThis spring represents the behavior of steel reinforcement in zone of plastic
hinge. The yield force of the spring is

stiffness of spring are equal to. The elastic and plastic

and, respectively.

Lap splice sub-spring
In case of RC column without confinement, the behavior of lap splice spring
follows the same concept as bond-slip spring. The calculation follows
section 0, in which the lap splice length
lengthis used instead of anchorage.

Fig 7: bond stress–slip model by Harajli (2009)

Since FRP wrapping around lap splice zone provides additional lateral stress,
thereby increasing the bond stress. Harajli (2009) proposed a bond-slip
model (Fig 7) for lap splice strengthened by FRP, the peak value of bondat bond splitting failure are given instress and corresponding slip
equations (18) and (19), respectively.

470

New Technologies for Urban Safety of Mega Cities in Asia

(18)

(19)
In whichis the maximum bond stress at pullout mode of bond failure

given as. Factorwith fully wrap

and partially wrap

which

represents the method of wrapping,taken as expression (20), in

is number of FRP strips with equal width.

(20)
As observed from eq.(18), bond strength is dependent on compressive(ratio of concrete coverstrength of unconfined concrete , and a ratio
depth to diameter of bar). Bond strength is also enhanced by increasing thenumber of FRP sheets or thickness of sheet. The effect of wrapping method
on bond strength is accounted for by factor , in which full wrapping
provides greater bond strength than partial wrapping.
Built-in Hysteretic Rules in Ruaumoko2DAll nonlinear springs described above are incorporated as back bone curvein Ruaumoko 2D. The model parameters are calculated from the actual
geometrical sections and material properties. The built-in degradation modeland hysteresis rules were combined with the above-mentioned envelope toprovide the complete cyclic spring models. In the present study, themodified Takeda Degrading Stiffness hysteresis is used for steel spring, theBi-linear with Slackness hysteresis is used for concrete spring and the SINA
Degrading Stiffness hysteresis is applied to shear spring.
Selected experimental program
Xiao and Ma (1997) conducted an experimental study on seismic retrofit ofreinforced concrete circular columns with poor lap-splice detail using
prefabricated composite jacketing. In the study, three half scale model
circular columns were tested. One column C1-A was tested under conditionof “as built” and the other two columns C2-RT4 and C3-RT5 were tested
after being strengthened with 4 and 5 FRP layers. All columns were 2.44m
tall and 0.61m diameter. Longitudinal reinforcements were 20 deformed #6
bars (

mm, 2% reinforcement ratio, grade 60) with lap splice) at the base. Round #2 hoops (mm) spaced at
length of 0.38m (127mm intervals were used as transverse reinforcement. Concrete strength
was 44.8 MPa (28 days cylinder specimen). Composite jacketing layer was
3.2mm thick prefabricated unidirectional glass fiber sheets. The elastic
modulus and ultimate strength in the circumferential direction are 48300

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer

471

October 2009, Incheon, Korea

MPa and 552 MPa, respectively. The sheets were attached to the column via
two part epoxy.
. An
The axial load applied to the column is 712 kN
analytical model was built to simulate these columns. Core concrete section(inside stirrup perimeter) was symmetrically divided into 42 discrete fibersof 1.30cm width. Thus, 42 springs with various properties were used tomodel confined concrete fiber and 11 steel springs were used to model all
reinforcing bars. Cover unconfined section (outside stirrup perimeter) was
symmetrically divided into 42 discrete fibers of 1.30cm width and 6 fibersof 1.50cm width. Thus a total of 48 springs with various properties wereused to represent unconfined concrete. One spring was used to modelcolumn shear behavior and one elastic element to represent elastic behaviorzone of column.
Harajli and Dagher (2008) conducted an experimental investigation on theuse of external fiber reinforced polymer (FRP) confinement for bondstrengthening of spliced reinforcement in rectangular reinforced concrete
columns and the consequent effect on the seismic response. Nine 0.4m deep
x 0.2 m wide x 1.5m high columns were divided into 3 series based on steel
diameter used; 14mm diameter series named C14FP1, C14FP2 and C14E;
16mm diameter series named C16FP1, C16FP2 and C16E; and 20mm
diameter series named C20FP1, C20FP2 and C20E. In each specimen label,suffixes “FP1” and “FP2” meant the number of FRP sheets, and suffix “E”
means column with no lap splice of reinforcing bars. Each specimen
consists of 8 reinforcing bars with lap splice length of. The ratio ofis 1.4, 2.1 and 1.0 for series C14, C16 andconcrete cover to bar diameterC20 respectively. Transverse steels were 8mm diameter spaced at 200mm
throughout the height of the strengthened column, while in unconfined “E”
column, stirrup was 8 mm diameter spaced at 50mm within 500mm fromthe base and spaced at 100mm within the remaining height. Yield strengthof bars

in series C14, C16 and C20 were 550MPa, 528MPa and 617MPa

varied from 32MPa to
respectively. Compressive strength of concrete
40MPa. The FRP sheets were 0.13mm thick; with elastic modulus of
230000MPa and tensile fracture strain of 1.5%. An analytical model wasbuilt to simulate these specimens. Core section (inside stirrup perimeter)
was symmetrically divided into 42 discrete fibers of 0.857cm width, thus 42
springs were used to model confined concrete fiber and 3 (or 4 in seriesC16) steel spring combinations were used to model all reinforced bars.
Cover unconfined concrete part (outside stirrup perimeter) was
symmetrically divided into 42 discrete fibers of 0.857cm width and 6 fibersof 0.667cm width, thus 48 springs were used to represent unconfinedconcrete. One spring was used to model column shear behavior and one
elastic element to represent elastic behavior zone of column. The behaviorof analytical model was compared with corresponding experimental result
shown in the next section.

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New Technologies for Urban Safety of Mega Cities in Asia

Verification of the nonlinear modeling
Series C14 tested by Harajli and Dagher (2008)

Fig 8: Bond stress–slip in C14 series

Fig 8 presents the backbone relation between bond slip and ratio of bondstress ( ) to unconfined concrete compressive strength ( ) as explained
in section 0. This backbone relation is combined with the built-in hysteresis
rules to obtain the complete cyclic bond-slip model. According to the model,
reach maximum values of 0.976, 1.068 and 1.157 inratiosspecimens C14, C14FP1 with one FRP layer and C14FP2 with two FRP
layers, respectively.
Table 1 shows the comparison between experimental and analytical resultsof series C14. The maximum experimental lateral force of columns C14,
C14FP1 and C14FP2 was 81.2, 87.2 and 92.2 kN respectively while theanalysis was 82.0, 92.3 and 97.2 kN respectively. The differences are only
1%, 6% and 5% respectively. It is found that in both analytical andexperimental results, the lateral force increased with the increasing number
of FRP sheets.
Table 1: Series C14 results
Specimen
C14
C14FP1C14FP2Lateral force – kN
Exper. Analysis
81.2
82.0
87.2
92.3
92.2
97.2
Average
S.D

Differ.
1.01
1.06
1.05
1.04
0.03

Type of lap splice failure
Before yielding of bar
Before yielding of bar
After yielding of bar

Fig 9b and Fig 10b show analytical response of series C14, which
demonstrates the performance of FRP wrapping to confine lap splice of RC
column. Fig 9a and Fig 10a show corresponding experimental results. It isnoted that the analytical results agreed well with experimental ones.

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer473

October 2009, Incheon, Korea

Fig 9: Response of columns C14 and C14FP1

Fig 10: Response of columns C14 and C14FP2

Series C16 tested by Harajli and Dagher (2008)

Fig 11: Bond stress–slip in C16 series

Fig 11 presents the backbone relation between normalized bond stressversus slip obtained from the model. The ratios
reach maximum
values of 1.304, 1.375 and 1.443 in specimens C16, C16FP1 with one FRP
layer and C16FP2 with two FRP layers, respectively.
Table 2: Series C16 results
Lateral force
Type of lap splice failure
Exper. Analysis Differ.
C16
107.4
97.9
0.91
After yielding of bar
C16FP1
112.5
108.0
0.96
After yielding of bar
C16FP2
107.4
109.0
1.01
After yielding of bar
0.96
Average
0.05
S.D
Table 2 shows the comparison between experimental and analytical resultsof series C16. The maximum experimental lateral force of columns C16,
C16FP1 and C16FP2 was 107.4, 112.5 and 107.4kN while the analysis gave
the values of 97.9, 108.0 and 109.0 kN respectively. The differences
Specimen

474

New Technologies for Urban Safety of Mega Cities in Asiabetween results are 9%, 4% and 1% respectively. It is found that in theanalysis results, the lateral force increased with increasing number of FRP
sheets, while the experiment gave strange results with column C16FP2
wrapped by two FRP layers has the lateral strength equal to un-strengthened
column C16 and less than the strength of column C16FP1 with one FRP
layer.
Fig 12b and Fig 13b show analytical response of series C16, which
represents the enhancement of the lateral capacity and the ductility provided
by FRP confinement around lap splice zone. Fig 12a and Fig 13a showcorresponding experimental results. It is found that the analytical results
agreed closely with experimental ones.

Fig 12: Response of columns C16 and C16FP1

Fig 13: Response of columns C16 and C16FP2

Series C20 tested by Harajli and Dagher (2008)

Fig 14: Bond stress–slip in C20 series

Fig 14 presents the backbone relation between normalized bond stressversus slip as obtained from the model. The ratios
reach maximum
values of 0.795, 1.025 and 1.120 in specimens C20, C20FP1 with one FRP
layer and C20FP2 with two FRP layers, respectively.
Table 3 shows the comparison between experimental and analytical resultsof series C20. The maximum experimental lateral force of columns C20,
C20FP1 and C20FP2 was 91, 126 and 141.8 kN while the analysis gave thevalues of 83.9, 130 and 135 kN respectively. The differences are 8%, 3%

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer

475

October 2009, Incheon, Korea

and 5% respectively. It is found that in both analytical and experimental
results, the lateral force increased with increasing number of FRP sheets.
Table 3: Series C20 results
Lateral force
Type of lap splice failure
Exper. Analysis Differ.
C20
91
83.9
0.92
Before yielding of bar
C20FP1
126
130.0
1.03
Before yielding of bar
C20FP2
141.8
135.0
0.95
Before yielding of bar
0.97
Average
0.06
S.D
Fig 15b and Fig 16b show analytical response of series C20, which
demonstrate the increase of the lateral capacity and the ductility provided by
FRP wrapping around lap splice zone. Fig 15a and Fig 16a showcorresponding experimental results. As shown, the analytical results agreed
well with experimental ones.
Specimen

Fig 15: Response of columns C20 and C20FP1

Fig 16: Response of columns C20 and C20FP2

Circular RC columns tested by Xiao and Ma (1997)

Fig 17: Bond stress–slip in Xiao and Ma (1997) columns

476

New Technologies for Urban Safety of Mega Cities in Asia

Fig 18: Response of columns C1-A; C2-RT4 and C3-RT5

Fig 17 presents the backbone relation between normalized bond stressreach maximum
versus slip as obtained from the model. The ratios
values of 1.239, 1.678 and 1.779 in specimens C1A, C2-RT4 with four FRP
prefabricated plates and C3-RT5 with five FRP prefabricated plates,
respectively. Table 4 shows the comparison between experimental andanalytical results of Xiao’s columns. The maximum experimental lateralforce of columns C1-A, C2-RT4 and C3-RT5 was 231, 290 and 330 kN
while analysis gave the values of 228, 276 and 289 kN respectively. The
differences between results are 1%, 5% and 10% respectively. It is foundthat in both analytical and experimental result, the lateral force increased
with increasing number of FRP prefabricated plates.
Table 4: Xiao’s columns results
Lateral force
Type of lap splice failure
Exper. Analysis Differ.
C1-A
231
228.0
0.99
Before yielding of bar
C2-RT4
290
276.0
0.95
After yielding of bar
C3-RT5
330
298.0
0.90
After yielding of bar
0.95
Average
0.04
S.D
Fig 18a, b, c show both analytical and experimental responses of columns
C1-A, C2-RT4 and C3-RT5. As seen, the lateral capacity and the ductility
Specimen

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer

477

October 2009, Incheon, Korea

of column strengthened by FRP wrapping around lap splice zone of RC
column were increased. It is noted that the actual columns tested in Xiao
and Ma (1997) experiment was wrapped by FRP prefabricated plates not
only around the lap splice zone, but also around the middle and top parts ofcolumn.
Conclusion
The nonlinear analytical model was constructed to simulate the cyclic
response of RC columns strengthened by FRP confinement around lap
splice zone. The model consisted of one elastic frame element and an
assembly of nonlinear springs, to simulate the elastic zone of RC column aswell as the plastic hinge region. The effect of FRP confinement around lap
splice zone is taken into account by applying confined bond-slip model ofspliced bars. Through the increase of FRP layers, the splice strength andductility is enhanced.
The comparison between model predictions and experimental results showsa good agreement. The discrepancy is within the range of 10%. The analysis
results can be used to predict the responses of column with lap spliceconfined by FRP jacketing. The model is found to be widely applicable. It
can be used to predict both rectangular and circular cross section.

Acknowledgement
The author would like to express his appreciate to the Asian Development
Bank (ADB), Japanese Government for granting the scholarship for his
study at SIIT. The authors are also grateful to Thailand Research Fund toprovide the research grant RSA 5280034.
Nomenclature
The following symbols are used in this paper:
Shear span of column
Gross area of section
Area of concrete in a fiber
Area of concrete core
Area of reinforcement (total in fiber)
Area of transverse reinforcement
Section width
Width of a FRP strip
Smaller of (1) distance from center of bar to the nearest
concrete surface and (2) one-half center-to-center spacing ofbars.
Effective depth of column section
Diameter of reinforced bar
Modulus of elasticity of concrete
Modulus of elasticity of transverse FRP
Modulus of plasticity of reinforcement
Modulus of elasticity of reinforcement

478

New Technologies for Urban Safety of Mega Cities in Asia

Yield force of concrete spring element
Compressive strength of unconfined concreteCompressive strength of confined concrete
Tensile strength
The lateral passive confining pressure
Stress of longitudinal reinforcement
Tensile strength of concrete
Yield stress of longitudinal reinforcement
Yield force of spring element
Yield stress of transverse reinforcement
Gap provided at the bottom of the jacket
Section depth
Height of column
Moment of inertia of the gross section
Shear degrading coefficientconfined strength ratio
Confinement effectiveness coefficient
Transverse reinforcement index
Length of elastic zone in bond model
Length of plastic hinge zone
Length lap spliced zone
Length anchorage bar zone
Length of plastic zone in bond model
Number of transverse FRP layers
Number of partial FRP strips
Number of lap splices in tension
Axial load applied on column
Local slip factor
Local slip at peak pullout mode failure
Spacing between transverse hoops or spirals
Distance of FRP strips
Local slip at peak bond strength
Thickness of one FRP layer
Average elastic bond stressMaximum bond stress at pullout mode
Local splitting bond stress
Average plastic bond stress
Shear strengthening coefficient of FRP
Shear strength of column without FRPRemain shear strength at collapse
Shear strength of column with FRP

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer479

October 2009, Incheon, Korea

Lateral displacement at

Bond slip of reinforcement

Lateral displacement at shear strength

Factor of partial wrapping
Concrete strain at stress of 50% of peak stress
Concrete strain for confined concrete
Concrete strain at the intersection point between the 1st and2nd stage of the stress–strain curve
Elastic strain
Strain at max stress of unconfined concrete
Strain of reinforcement
Critical crack angle at shear failure
Coating factor
Reinforcement size factor
Reinforcement location factor
Lightweight aggregate concrete factor
Parameter of ratio of FRP amount to concrete
Reference
ACI318 (2005). "ACI 318-05, Building Code Requirements for Structural
Concrete and Commentary." American Concrete Institute ACI Committee
318, 2005, 430 pp.
ATC-40 (1996). Seismic evaluation and retrofit of concrete buildings (vol 1),
Applied Technology Council.
Carr, A. J. (1998). Ruaumoko - Program for inelastic dynamic analysis,
Christchurch: Department of Civil Engineering, University of Canterbury.
Harajli, M. H. (2009). "Bond strengthening of lap spliced reinforcement
using external FRP jackets: An effective technique for seismic retrofit ofrectangular or circular RC columns." Construction and Building Materials
23(3): 1265-1278.
Harajli, M. H. and F. Dagher (2008). "Seismic Strengthening of BondCritical Regions in Rectangular Reinforced Concrete Columns Using Fiber-

480

New Technologies for Urban Safety of Mega Cities in Asia

Reinforced Polymer Wraps." ACI Structural Journal Volume: 105 Issue: 1
Pages: 68-77.
Harajli, M. H., E. Hantouche, et al. (2006). "Stress-Strain Model for FiberReinforced Polymer Jacketed Concrete Columns." ACI Structural Journal
Volume: 103 Issue: 5 Pages: 672-682.
Lowes, L. N., N. Mitra, et al. (2003). "A Beam-Column Joint Model for
Simulating the Earthquake Response of Reinforced Concrete Frames."
Pacific Earthquake Engineering Research Center PEER 2003/10.
Matrin, S. (2007). "Nonlinear modeling of gravity load designed reinforced
concrete buildings for seimic performance evaluation." Msc degree Civil
Engineering Department. Asian Institute of Technology. Bangkok, Thailand.
Moehle, J. P., K. J. Elwood, et al. (2000). "The Second U.S.-Japan
Workshop on Performance-Based Earthquake Engineering Methodology for
Reinforced Concrete Building Structures " Pacific Earthquake Engineering
Research Center PEER 2000/10.
Priestley, M. J. N. and F. Seible (1991). "Seismic Assessment and Retrofitof Bridges." University of California, San Diego SSRP 91/03 pp. 84-149.
Roy, H. E. H. and M. A. Sozen (1965). "Ductility of Concrete." American
Concrete Institute Volume: 12 Pages: 213-235 Date: January 1, 1965.
Sezen, H. (2002). "Seismic Behavior and Modeling of Reinforced Concrete
Building Columns." Ph.D. Thesis. University of California, Berkeley.
Sezen, H. and J. p. Moehle (2003). "Bond-slip behavior of reinforced
concrete members." fib - Symposium (CEB-FIP); Concrete Structures in
Seismic Regions 6-9 May 2003. Athens, Greece.
Shima, H., L. L. Chou, et al. (1987). "Bond Characteristics in Post-Yield
Range of Deformed Bars." Concrete Library of JSCE 10: 113-124.
Xiao, Y. and R. Ma (1997). "Seismic Retrofit of RC Circular Columns
Using Prefabricated Composite Jacketing." Journal of StructuralEngineering 123(10): 1357-1364.
Ye, L., Q. Yue, et al. (2002). "Shear Strength of Reinforced Concrete
Columns Strengthened with Carbon-Fiber-Reinforced Plastic Sheet."
Journal of Structural Engineering 128(12): 1527-1534.

Modeling of RC Column with Lap Splices Strengthened by Fiber Reinforced Polymer

481

AN EXPERIMENTAL STUDYFOR THE QUALITY EVALUATION
OF COVER CONCRETE
KENJI HAYAKAWA
Tokyu Construction Co. Ltd., Tokyo, Japan
hayakawa.kenji@tokyu-cnst.co.jp
YOSHITAKA KATO
ICUS, Institute of Industrial Science, The University of Tokyo, Japankatoyosh@iis.u-tokyo.ac.jp

ABSTRACTThe quality of cover concrete, which is affected by the execution
conditions of works such as consolidation and curing, strongly influences
the durability of concrete structures. Currently, the quality of the structuralconcrete is confirmed by examining the fresh properties and compressive
strength of a test specimen. However, these examinations do not evaluate
the durability of the structural concrete directly, and the influence of theexecution condition of work is uncertain.
The purpose of this study is to evaluate the influence of the execution
condition of works on the cover concrete quality for ensuring the durabilityof structure concretes. This experiment investigated the air permeability
index, percentage of voids, and carbonation depth in test and full size
specimens under variable execution condition of works and variable slump
and cement type of the concrete materials. Air permeability test of theconcrete surface was carried out by the Torrent method for non-destructive
test which can be utilized in the field.
As a result, the air permeability examination can evaluate the qualityof cover concrete by the difference of curing days. In this case, variation of
air permeability index for full size specimen is larger than that of small size
specimen. This can be attributed to the fresh concrete properties such as
bleeding of concrete, consolidation times, and compaction by the self-weight.
Finally, concrete using Portland blast-furnace slag cement is more easily
affected by curing condition and execution of work than that using ordinary
Portland cement.

1. INTRODUCTION
Durability of concrete structures depends on the mass transfer resistance ofcover concrete, which is a primary factor in deterioration due to chloride ion
and carbon dioxide, oxygen, water. Therefore, the quality of the coverconcrete is very important for ensuring the concrete structures’ durability.
The quality of cover concrete is influenced by factors other than the watercement ratio, especially the execution conditions of works such as the483

October 2009, Incheon, Korea

consolidation and curing method, and the relative influence is different for
constructive quality of fresh concrete such as workability and consistency.
Currently, the quality of structural concrete is confirmed byexamination of the fresh condition, such as slump, and the compressive
strength of test pieces. However, these examinations do not evaluate thedurability of the structural concrete directly, and the influence of execution
condition of work is uncertain. If the evaluation of quality of cover concrete,such as permeability, could be conducted directly on the structures, it would
be very effective for ensuring durability. Therefore, this study utilized
nondestructive testing methods which can examine air-permeability on the
structures. The purpose of this study is to evaluate the influence of theexecution condition of works on the quality of cover concrete for ensuring
structural concrete durability. This experiment investigated air permeability
index, percentage of voids, carbonation depth in test and full size specimens
under variable execution condition of works and testing pieces. Also, theinfluence of construction works and conditions was evaluated by comparing
full size specimens to test pieces.

2. TEST PROCEDURE
2.1 Materials
Mix proportions are given in Table 1. In this study, ready mixed
concretes which satisfy JIS A 5308 were used. Three types of concrete withdifferent slump and cement types were investigated. Ordinary Portland
cement and Portland blast-furnace slag cement were both used, and thewater-cement ratio of these mix proportions was set at 55.1 and 57.0%. The
slump for water unit weight of 180 kg/m3 was 18.0 cm, whereas the slump
for water unit weight of 159 kg/m3 was 8.0 cm.
Table 1 Concrete mix proportions
Air W/C s/a
Unit Weight(kg/m3)
No.
(％) (％) (％) Ｗ
Ad.
Ｃ
Ｓ
Ｇ
1
4.5 57.0 46.6 159 279 858 1002 2.79
2
4.5 57.0 49.3 180 316 866 906
3.16
3
4.5 55.1 46.1 159 289 840 1002 2.89
※1：Strength-slump-Maximum Aggregate Size（Cement type）※2: AE water reducing agent
ConcreteType24-8-20N
24-18-20N
24-8-20BB

2.2 Specimens and conditions
Figure 1 illustrates the full size specimen dimensions and reinforcing
steel bar arrangement. The dimension of specimens similar to the original
structure is 1.0×1.0×1.0m (Series 1) with no reinforcement, and 0.9×0.9
×1.2m (Series 2) with reinforced (both form sides) and non-reinforced

484

New Technologies for Urban Safety of Mega Cities in Asia

cases in order to investigate the influence of reinforcing steel bar on coverconcrete quality. The side surface was also investigated for some specimens.

1200

D22 80mm ピッチ
D22@80mm

D16
125mm ピッチD16＠200mm

900

100

900

Figure 1 Full size specimen dimensions and rebar arrangement
Table 2 shows the construction works and specimen conditions.
Concrete was cast using a concrete pump-piston and consolidated with ahigh-frequency vibrator of φ 50 mm. Vibration time is 15 seconds forstandard construction works, and was determined from experience andcompressive strength. In addition to the standard time, 45 seconds vibrationcase was also investigated to examine the most suitable vibration time forconcrete quality of fresh condition. The curing conditions were varied by
the removal time of forms and moist curing after form removal. After curing
specimens were exposed to a warm outdoor environment unaffected bychloride ions.
Table2 Construction works and specimen condition
Execution condition and Parameter
Series1
Non-reinforced (Concrete mix 1)
CastingJune (concrete temperature 28ºC )Casting speed
5 m/h (Continually)
Curing times
4 days, 7 days, 28 days (removed form)
Series2
Reinforced and non-reinforced (Concrete mix 1-3)
Casting
March (concrete temperature 13 to 17ºC)
Casting speed
2 to 3 m/h
Vibration times 15 seconds, 45 seconds
Curing times
1 day, 5 days (removed form)
9 days, 28 days (moisture after removing at 5 days)
3.3 Test items and methods
Table 3 shows the test items and methods. The fresh condition was
examined by slump, air content, concrete temperature, and bleeding tests,
which are performed for the acceptable inspection of ready mixed concrete.

An experimental study for the quality evaluation of cover concrete

485

October 2009, Incheon, Korea

In order to investigate the fundamental characteristics of the concrete
mixes, compressive strength (φ10×20 cm), air permeability at the concretesurface (15×15×15 cm), and accelerated carbonation (φ10×20cm) tests
were performed on test pieces. These pieces were exposed to 20ºC and 60%
RH after water curing until 28 days. Air permeability was tested by the nondestructive Torrent method which can also be used in the field (Torrent,1992). This method uses a two-chamber cell, with an inner and outerchamber, based on the guard-ring principle. Since the air permeability is
generally influenced by the water content at the concrete surface (Ujike,1988), the water content ratio at the concrete surface was measured bycapacitance measurement method, and air permeability was tested during
dry periods.
Testing of the full size specimens examined air permeability andmoisture ratio at the concrete surface. Carbonation depth was measured forone specimen by taking drilled cores. These results were compared to test
piece results, which were not influenced by construction works andconditions.
Table 3 Tests items and method
Tests items
Test method
Tests on fresh condition
Slump, Air, Temperature
JIS A 1123: Bleeding of concrete
Air permeability
Torrent method (Torrent, 1992)
Compressive strength
JIS A 1107, 1108
Moisture ratio
Capacitance measurement method
Air space ratio
ASTM C 642
Carbonation depth
JIS A 1151: Method for measuring depth
JIS A 1152: Accelerated test
20ºC, 60% RH, CO2 5%

3. TEST RESULTS AND DISCUSSION
3.1 Fresh condition concrete quality
Table 4 shows the test results for fresh conditions. These concrete
mixes satisfied the standard values specified by JIS A 5308. The bleeding
content and ratio of 24-18-20N and 24-8-20BB is larger than that of 24-820N.

ConcreteType24-8-20N
24-18-20N
24-8-20BB

486

Table 4 Fresh conditions test results
Bleeding
Concrete
Bleeding
Slump
Air
Temp.
Temp.
Content
Ratio（cm） （%）（ºC）（ºC）（cm3/cm2） （%）
6.5
4.9
17.1
11.9
0.074
1.85
16.0
5.3
16.0
9.1
0.148
3.58
10.0
3.1
13.4
8.2
0.128
3.04

New Technologies for Urban Safety of Mega Cities in Asia

3.2 Test pieces fundamental characteristics
Table 5 shows the compressive strength at 28 days, surface airpermeability, and air space ratio at 100 days in dry conditions, andaccelerated carbonation depth at 28 days. The compressive strengths used
for inspection of the ready mixed concrete were 29.7 to 34.1 N/mm2, larger
than the nominal strength of 24 N/mm2, and had little difference between
concrete mixes. However, the difference between the direct durability
indices – the coefficient of air permeability at 100 days and accelerated
carbonated depth at 28 days – was greater than the difference incompressive strength.
Table 5 Test results for fundamental quality of concreteCompressive
Coef. of
Carbonated Depth
Air space(Accelerated
Strength
AirRatio
curing：28 days)(N/mm2)permeability
（%）
-16 2
（mm）
（10 m ）
24-8-20-N
0.207 (0.16)
9.0
9.8
33.9
24-18-20-N
29.7
0.402 (0.36)
10.3
12.0
24-8-20-BB
34.1
0.114 (0.14)
7.0
13.9( )：Coefficient of variation
Figure 2 shows the relationship between age of concrete test pieces
and coefficient of air permeability and moisture ratio. The coefficient of air
permeability was below 0.1×10-16m2 at 35 days (7 days exposed in dry
condition) and increased gradually. The moisture ratio at 35 days was about
7 to 7.5%, and decreased gradually to about 5 to 5.5% over the drying
period. Air permeability showed the influence of water content in concrete,
primarily because air permeability increased as moisture content decreased
over the drying period. It is therefore important to note the influence ofwater content on air-permeability when examining in the field.
24-8-20N
24-18-20N
24-8-20BB

1

Moisture ratio（%）

Coeff. of air-permeability（10-16m2）

10

0.1

0.01
0

30
60
90
Concrete age(day)

120

8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0

24-8-20N
24-18-20N
24-8-20BB

0

30
60
90
Concrete age(day)120* Dry condition from 28 days
Figure 2 Relationship between concrete age and coefficient of air
permeability and moisture ratio

An experimental study for the quality evaluation of cover concrete487

October 2009, Incheon, Korea

When comparing concrete types, the coefficient of air permeability for
24-18-20N is higher than 24-8-20N with the same water-cement ratio due tothe unit water content. 24-8-20BB using blast-furnace slag cement is lower
than 24-8-20N with the same water-cement ratio in the case of normal
curing at 28 days in 20ºC water, but the carbonated depth for blast-furnace
slag cement was larger than for ordinary Portland cement due to thedifference in alkali quantity.
3.3 Influence of construction works and condition
Figure 3 shows the effect of curing time on the coefficient of air
permeability at the concrete surface. Upper, middle, and lower areas areplotted as well as the average of the three values. The coefficient of air
permeability decreased with curing time, and some correlation between thecoefficient of air permeability and carbonation depth could also be seen in
Figure 3. These results shown that it is possible to determine the extent of
curing by the coefficient of air permeability at the concrete surface.
coeff. of air-permeability(10-16 m2 )upper
middle
Lower
Avg.

1

15
Carbnation depth（mm）

10

Upper
28days after accelated

Lower

10
9 months

5

0

0.1
0

7
14
21
28
Curing piriod(days)

0.01

0.1

1

10

Coeff. of air-permiability(10-16 m2 )Figure 3 Test results of coefficient of air permeability and carbonation
depth (Series 1, 24-8-20N)
Figure 4 shows the coefficient of air permeability results and theirrelated coefficient of variation for various construction works andconditions. In this case, the form was removed at 5 days. Comparing
reinforced and non-reinforced results, it can be seen that for reinforced
specimens the air permeability in all areas of the specimens are fairly
similar, whereas for non-reinforced specimens measurements in the upperarea tended to be larger than the middle and lower areas. This is because theconcrete is affect by consolidation due to self-weight and bleeding. Thiseffect wasn’t seen in the case of reinforced concrete because the reinforcing
steel-bar affected the self-load of the cover concrete.
For vibration time, vibrating for 45 seconds resulted in lower air
permeability and lower coefficient of variation than the 15 seconds standard
vibration time used in real construction works. The fact that coefficient of
air permeability at the concrete surface and the coefficient of variation

488

New Technologies for Urban Safety of Mega Cities in Asia

120
100
80
60
40
20
0
0
0.1
1
10
Coeff. of air-permeability(10-16 m2 )

120
100
80
60
40
20
0

Height of specimin(cm)Height of specimin(cm)decreased for long vibration times suggests that the vibration time
appropriate for permeability is different than that appropriate forcompressive strength for the concretes used in this study.

nonreinforcing -15sec
nonreinforcing-45sec
reinforcing -15sec
reinforcing-45sec

0.5
1
Coeff. of variation

1.5

Figure 4 Influence of reinforcement and vibration time for consolidation(Removed form at 5 days, 24-8-20N ordinary Portland cement, tested at 91
days)

120
100
80
60
40
20
0

120
100
80
60
40
20
0
0
0.1
1
10
Coeff. of air-permeability(10-16m2 )Height of specimin(cm)Height of specimin(cm)Figure 5 shows the influence of reinforcement and concrete slump.
The coefficient of air permeability and variation for 18cm slump are larger
than those of 8cm slump. One reasons for this result is that the airpermeability of concrete itself is largely influenced by the unit water content.
It is also possible that the coefficient of variation for 18cm slump increased
due to excess vibration. However, it should be noted that segregation suchas aggregate settling and bleeding due to vibration occur for concretes withhigh slump which are consolidated by excess vibration.

nonreinforcing-8cm
reinforcing-8cm
nonreinforce-18cm
Riinforcing-18cm

0.5
1
Coeff. of variation

1.5

Figure 5 Influence of reinforcement and concrete slump(Removed form at 5 days, ordinary Portland cement, test at 91 days)
Figure 6 shows the influence of reinforcement and curing period.
When comparing different cement types, the air permeability of concrete
using blast-furnace slag cement and removed at 5 days was generally higher
than that of concrete using ordinary Portland cement. There was little effectobserved due to extended curing time in the case of removal at 12 days.

An experimental study for the quality evaluation of cover concrete

489

120
100
80
60
40
20
0

120
100
80
60
40
20
0
0
0.1
1
10
Coeff. of air-permeability(10-16 m2 )Height of specimin(cm)Height of specimin(cm)October 2009, Incheon, Korea

nonreinforcing-5 days
nonreinforcing-12days
reinforcing-5days

0.5
1
Coeff. of variation

1.5

Figure 6 Influence of reinforcement and curing period(Removed form at 5 days, 24-8-20BB blast furnace-slag cement, tested at 91
days)

Height of specimens

4.9
5.6
5.1
5.5
4.8
5.7
5.8
5.6
5.5
5.3
5.4
5.2
4

5

6

Moisture ratio(%)

7

5.6

45

5.3

45

4.9

45

6.5

45

5.4

45

5.0
4

5

6

20 60 100 20 60 100

45

Unreinforced Reinforced

Vibration times
20 60 100 20 60 100

45
15
45
15
45
15
45
15
45
15
45
15

Unreinforced Reinforced

100
60
100
60
20

Unreinforced

20

Reinforced

The test results presented in Figures 4 through 6 were measured at 91
days, and the moisture ratios at the concrete surface at the measurement
time were 4.4% to 5.8% (Figure 7). However, as was shown in Figure 2, thecoefficient of air permeability is affected by the moisture ratio. Therefore,
for comparing the full size specimens to the test piece, the average of test
pieces results measured at 70 and 100 days is used because they have
similar moisture ratio and concrete age.

7

Moisture ratio(%)

15

5.3

15

5.1

15

5.0

15

4.9

15

4.4

15

4.7
4

5

6

7

Moisture ratio(%)

Figure 7 Moisture ratio of full size specimens
Figure 8 shows the ratio of the coefficient of air permeability
affected by construction works and condition. The air permeability ratio of
24-8-20N and 24-18-20N with ordinary Portland cement was near 2,
particularly for the 45 seconds vibration cases, but a few test results for theupper area were largely influenced by bleeding and low consolidation due toself weight. These test results were measured in the condition where forms
were removed at 5 days. The coefficient of air permeability decreases as
curing period increases, as shown in Figure 9, so the air permeability ratio
will be smaller than the 5-day curing case if the curing period is extended.

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New Technologies for Urban Safety of Mega Cities in Asia

Height of specimens

45
15
45
15
45
15
45
15
45
15
45
15
0

5

45
45
45
45
45
45

10

0

5

20 60 100 20 60 100

Unreinforced Reinforced

20 60 100 20 60 100

Vibration times
Unreinforced Reinforced

100
60
100
60
20

Unreinforced

20

Reinforced

On the other hand, the air permeability ratio of Portland blast-furnace
slag cement is larger than the case for ordinary Portland cement. Thesetendencies are different from the results of test pieces for standard curing,suggesting that the influence of curing and bleeding is strong in the field.

15
15
15
15
15
15
0

10

5

10

Ratio of coefficient of air permeability (full size specimens / test pieces)24-8-20N
24-18-20N
24-8-20BB

Coeff. of air
permeability(10-16 m2 )Figure 8 Ratio of coefficient of air permeability affected by construction
works and conditions
1

0.1
0

7

14

21

28

Curing time(day)Figure 9 Relationship between concrete age and coefficient of air
permeability (24-8-20N, vibration time 15 seconds, non-reinforced)

4. CONCLUSION
This study carried out an experimental investigation to evaluate theinfluence of the execution condition of works on the quality of coverconcrete for ensuring the durability of structure concretes. The conclusionsof this study are as follows:
1) The air permeability examination used this study may be able toevaluate the quality of cover concrete by the difference in curing time.

An experimental study for the quality evaluation of cover concrete491

October 2009, Incheon, Korea

2) Air permeability index for full size specimens is larger than that of small
size specimens (test pieces). This is due to the fresh concrete properties
such as bleeding, consolidation time, and compaction by self-weight.
3) For concrete with 8cm slump, the air permeability index tended todecrease for of vibration times longer than the standard method. This
result suggests that the vibration time appropriate for permeability isdifferent than that appropriate for compressive strength.
4) The concrete which used Portland blast-furnace slag cement was moreeasily affected by the curing conditions and execution of work thanconcrete used ordinary Portland cement.
ACKNOWLEDGEMENT
The authors would like to express their thanks to Mr. Michael W. Henry of
Katoyosh Laboratory, University of Tokyo who generously assisted.
REFERENCES
Torrent, R.J., 1992. A two-chamber vacuum cell for measuring thecoefficient of permeability to air the concrete cover on site. Materials andStructures, Vol. 25, pp.358-365.
Isao UJIKE and Shigeyoshi NAGATAKI, 1988. A study on the quantitativeevaluation of air permeability of concrete. Journals of the Japan Society of
Civil Engineers, Vol.396/V-9, pp.79-87

492

New Technologies for Urban Safety of Mega Cities in Asia

THE SECULAR CHANGE OF
TIMBER BRIDGE, “KINTAI-KYO”
Mikio KOSHIHARA
Institute of Industrial Science, the University of Tokyo,
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
kos@iis.u-tokyo.ac.jp

ABSTRACTThe timber bridge, “KINTAI-Kyo”, is located in Iwakuni City,
Yamaguchi Prefecture, JAPAN. It was built in 1673 and rebuilt several
times until 2001 for washed away or its deterioration.
In 2001 “KINTAI-Kyo” was rebuilt as same shape in 1953. It is marked by
the beauty of its five arches. The bridge length is 193m, every arch length isabout 35m, its rise is about 5m and the wide is 5m. This bridge was made bysome structural elements, KYOROKU(timber beam), KURA-GI(timber
bracing), TASUKE-GI(timber parts), TAGA(iron hoop), KASUGAI(ironcramp), DABO(timber shear connector), etc.
After rebuilt in 2002, the shape of bridge, temperature and humidity
are measured. The following results were provided by these measurements.
In the first year, the deformation at the center of bridge move 2cm
downward for gaps between the structural elements. And there is a seasonalchange of the deformation at the center of the bridge. At the center of bridge
it moves upward in summer and downward in winter. The range of seasonalchange is about 2cm. These changes are influences by temperature andhumidity. In 2005 the irregular change of shape was observed in the autumn
because no.1 bridge was washed away by the typhoon. These measurements
have a possibility of safety diagnosis for timber bridge.

1. INTRODUCTION
Figure.1 shows an elevation of “KINTAI-KYO” bridge. The bridge consistsof five timber ones and is supported on each stone pillar. The bridge is
193.3m long and 5m wide. Three bridges of the middle part, from No.2 to
No.4, are 35.1m long and the rise is about 5m.
It was constructed first in 1673 of Edo era by a feudal lord of the time,
Hiroyoshi Kikkawa, to meet the transportation problems which the people
faced every time when the Nishiki River flooded. The structural idea of thebridge is said to have come from a story of a Chinese priest of the Ming
Dynasty who settled in Japan about the arch-type stone bridges of China.

493

October 2009, Incheon, Korea

Unfortunately, the entire bridge was washed away by a flood in May, 1674.
But it was reconstructed in October, 1674. After that the bridges were often
repaired and reconstructed partially. Figure.2 shows the history of repair andreconstruction of the bridge. Each bridge was repaired about every 12–15
years and reconstructed about every 20 years. The bridge we can see today
was constructed in 1953, because the entire bridge was washed away by aflood due to a typhoon in 1950, and a replica of the original bridge wasreconstructed after the Edo design. This bridge has long life of about 50
years with replacement of the floorboards in 1967. The entire bridge wasreconstructed from 2001 to 2004.
“KINTAI-KYO” bridge is composed of a lot of members. The main
structure is KYOROKU (girder). The KYOROKU is composed of KETA
(beam), KURAGI, TASUKEGI, HEIKINGI and ATOZUME. They areconnected with DABO (dowels), KASUGAI (cramps), nails and
MAKIGANE (hoops), as shown in Fig.2.
There are past researches about the secular changes of “KINTAI-KYO”.
The properties of vibration are measured and static loading tests wereconducted by Waseda university[1]-[3] from 1953 with the interval of 5
years.

Figure 1: Elevation of “KINTAI-KYO” bridge

Figure 2: Detail of“KINTAI-KYO” bridge

Photo 1: “KINTAI-KYO” bridge

2. MEASUREMENT METHOD
2.1 Measurement Plan

494

New Technologies for Urban Safety of Mega Cities in Asia

The bridge shape and factors of change are being measured from2003. In this year the no.4 and no.5 bridges were completed and just one
year was passed from the no.3 bridge was completed. The no.2 and no.1
bridges were reconstructed in 2004 and there are the no.2 bridge passed
about 50 years in 2001.
2.2 Shape
The shapes of the middle
three bridges (no.2, no.3 and no.4) arebeing measured with theodolite. 13
targets were measured on every one
side of bridge and 26 targets were
measured on every bridge. Target
points are the rivets bottom of thebalustrades(Photo.2).
Measurements were started on
March 14, 2003. In the first month
the shape was measured with theinterval of one week and in next twomonths it was measured with theinterval of two weeks. After threemonth it was measured with theinterval of one month and it wasmeasured every 3 month from August
1, 2005.
2.3 Temperature and humidity

Photo 2: Target point of
measurement

Photo 3: Thermo recorder

Temperature and humidity influence the water content and the strainof wood. Especially wooden bridge is located in hard environment, above
the river. Temperature and humidity under the bridge are being measured
with thermo recorder(TandD’s TR72S) every one hour(Photo.3).
2.4. Live load
The bridge is loaded by crossing persons and this load influences thedeformation of the bridge. The number of sold tickets to cross the bridge
was counted as the number of persons crossing bridge.
3. RESULTS
3.1 Secular change of the bridge shape
Figure.3 shows the deformation of the center of bridge. The
horizontal axis shows how many days passed from the completion of eachbridge. In the first year, from 0 to 365 days, the deformation of center of all
bridges went down about 2 cm. But the deformation of no.2 was a little

The secular change of timber bridge, “Kintai-Kyo”

495

October 2009, Incheon, Korea

small. It is because this no.2 bridge has completed lastly and there is noconstruction after completion. After the first year they go up in summer andgo down in winter. The width of change is about 1.5cm. The deformation ofeach point of no.4 bridge in the summer (Aug. 1, 2006) and in the winter(Feb. 1, 2007) are shown in Figure.4. The maximum deformation of bridge
is at the point of a third part of bridge.
0.005
no.2-upperno.3-upperno.4-upper

deformation (m)0.000-0.005-0.010-0.015-0.020-0.025-0.030-0.035
0

120

240

360

480

600

720

840 960 1080 1200 1320 1440 1560 1680 1800 1920 2040
Day from completion

Figure 3: Deformation of the center of bridge (Upper part of a river)
2003/3/14
2007/2/1
2006/8/1

405

The deformation is magnified by 50 times

Figure 4: The deformation of no.4 bridge (Upper part of a river)
0.02
405
deformation(m)

0.01

405U
405D
2003

0.00
-0.01
-0.02
-0.03
-0.04
01 04 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12
2002
2003
2004
2005
2006
2007
Month

Figure 5: The deference between the upper part and the lower part of theriver in bridge
The deference of the deformation between at the upper part andlower part of the river in bridge is shown in Figure.5. This figure shows thedeformation at the point 405 shown in Figure.4. The deformation at theupper part of the river in bridge is larger than at the lower part of the riverand its difference grows larger. The deference is about 1cm in 500cm width.
3.2 Factors of change
3.2.1 Temperature and humidity

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New Technologies for Urban Safety of Mega Cities in Asia

15
10
5
0
0

60
120
180
240
300
Day in 2003-2006 (from Jan. 1)

360

Figure 6: Change of temperature
100
90
Relative humidity (%)

Temperaturechanges
cyclically. The highest temperature,
about 30 degrees Celsius, wasrecorded in August and the lowest
temperature, about 5 degrees Celsius,
wasrecordedinFebruary.
Considering the change of relative
humidity, it is high because thisbridge is located above the river.
Especially it is over 90% in every
night and in every morning. But thechange in the year is not cyclicallyand it is different from every year.

Temperature (Cels.)

Temperature and humidity were measured by thermo recorder every
one hour. The results are shown in Figure 6 and Figure 7. Both temperature35
and humidity value are 7-day average
2003
30
before measuring the shape of bridges.
2004
2005
25
The horizontal axis shows how many
2006
20days from every January 1.

80
70
60

2003
2004
2005
2006

50
40
0

3.2.2 Live load

60
120
180
240
300
Day in 2003-2006(from Jan. 1)

360

the number of tickets

The number of sold tickets to
Figure 7: Change of relative
cross the bridge was counted. Thishumidityticket is round-trip ticket, so thenumber of crossing the bridge is twice
140000as this number. The number of sold
120000tickets in month is shown in Figure 8.
100000
About 80-240 thousand persons cross
80000
the bridge every month. There are two
60000
peaks and over 100 thousand persons
40000
cross the bridge in April and
2003
20000
2004
November. In April they enjoy the
0
0
60
120
180
240
300
360
cherry blossom on the bank of river
Day in 2003-2004 (from Jan. 1)
and in November they enjoy autumn
leaves. There is small peak in August
Figure 8: The number of persons
and this reason is summer vacation.
crossing the bridge
There are two off-peak in Julyand December. In June and July is therainy season in Japan and in December it is cold in Iwakuni-city.
These numbers are reference value and maybe lower limit because there
were the crossing persons who did not buy the tickets.
3.2.3 Gap of connectors“KINTAI-KYO” bridge is mainly composed of beams and thesebeams are connected to the other beam with dowels. These dowels are

The secular change of timber bridge, “Kintai-Kyo”

497

October 2009, Incheon, Korea

deformed by the shear force between beams. This deformation influences
the shape of the bridges. By the field experiments in 2003[4]-[5] it is cleared

Photo 4: Deformation of dowel

Photo 5: The damage of no.1 bridge
after Typhoonthat the vertical deformation of the center of bridge is 14.3mm if the gap
between beams is 0.28mm and that deformation is 27.39mm if the gap is
0.67mm. By the survey of elements when the bridge was taken to pieces, thedowels were deformed about 2-4mm as shown Photo 4.
3.2.4 Typhoon
On September 6, 2005, the column of the no.1 bridge was washedaway by a flood. The damage of no.1 bridge after typhoon 14 is shown in
Photo 5.

4. DISCUSSION
4.1 The degree of influence to secular change
Timber bridge, “KINTAI-KYO” is changing its shape secularly andcyclically. Considering the cause of secular change of wooden bridge, there
is many factors described in 3.2. In this chapter the degree of influence isconsidered.
4.2 Temperature and humidity
0.000▲ no.2deformation[m]-0.005○ no.3Temperature and humidity
× no.4-0.010influence to the moisture contents of-0.015
wooden members. Figure 8 shows the-0.020relation between the deformation of-0.025center of bridge and the moisture-0.030content. The moisture content of-0.035
wooden member is calculated-0.040according to the theory of Hawley,
5
10
15
20
25
Keywerth, Kollmann et.al.
moisture content[%]
In the no.3 and no.4 bridge the
Figure 8: Relationship between
correlation between the deformation
moisture content and deformationand moisture content, but in the no.2
bridge there is no correlation. In this figure the moisture content is changing

498

New Technologies for Urban Safety of Mega Cities in Asia

from 10% to 15%. If the moisture content of wooden member is change
from 10% to 15%, the change of length parallel to grain is about 0.15% andlength perpendicular to grain is about 1.5%. Supposing to the “KINTAIKYO” is a 5m depth beam, the total shrinkage of beam depth is about 75mm.
This deformation is larger than observed deformation. In the arch
construction the deformation of the center moved upper if the length of theelement is longer for the change of the moisture content of wooden elements.
This is the reason for the seasonal change.
Figure 9 shows the deformation of the center of bridge. The“KINTAI-KYO”, especially the no.1 bridge, suffered terrible damage in thetyphoon on September 6, 2005. In 2005 the irregular change of shape wasobserved from September to March, because no.1 bridge was washed awayby the typhoon. These measurements have a possibility of safety diagnosis
for timber bridge.
0.020

Typhoon
0.010
deformation[m]

no.3
0.000
-0.010no.2-0.020-0.030no.4-0.04001 03 06 09 12 03 06 09 12 03 06 09 12 03 06 09 12

2004

2005

2006

2007

Date

Figure 9: Deformation of the center of bridge and the Date

5. CONCLUSION
After rebuilt in 2002, the shape of bridge, temperature and humidity aremeasured. The following results were provided by these measurements.
In the first year, the deformation at the center of bridge move 2cm
downward for gaps between the structural elements. And there is a seasonalchange of the deformation at the center of the bridge. At the center of bridge
it moves upward in summer and downward in winter. The range of seasonalchange is about 2cm. These changes are influences by temperature andhumidity. In 2005 the irregular change of shape was observed in the autumn
because no.1 bridge was washed away by the typhoon. These measurements
have a possibility of safety diagnosis for timber bridge.

The secular change of timber bridge, “Kintai-Kyo”

499

October 2009, Incheon, Korea

ACKNOWLEDGEMENTS
The authors graciously acknowledge the financial support of the project
granted from Iwakuni-city, Yamaguchi prefecture.

REFERENCES[1] Takeshi SHINAGAWA: Report about reconstruction of “KINTAIKYO”, Iwakuni-city, 1955
[2] Kusuo AOKI: Report about static and dynamic tests of “KINTAI-KYO”,
1953[3] Research Center, Science Faculty, Waseda: Report about the Load Testof “KINTAI-KYO”,1998[4] Mikio KOSHIHARA et al.: A study about “KINTAI-KYO” in Iwakuni
Part 1-3, Summaries of technical papers of Annual Meeting Architectural
Institute of Japan. C-1, pp.277-283, 2002
[5] Mikio KOSHIHARA et al.: A study about “KINTAI-KYO” in Iwakuni
Part 4-6, Summaries of technical papers of Annual Meeting Architectural
Institute of Japan. C-1, pp.469-474, 2003

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New Technologies for Urban Safety of Mega Cities in Asia

THE SAFETY ASSESSMENT
TO URBAN CITY OF COASTAL AREA
BY WAVE-STRUCTURE INTERACTIONJINHONG KIM
Dept. of Civil Engineering, Chung-Ang University, Korea
Jinhkim@cau.ac.kr
SUNGDUK KIM
Dept. of Civil and Environment Engineering, Cheong-Ju University, Korea
Sungduk@cju.ac.kr

ABSTRACTThe present study is to estimate the wave height at the front face of
breakwater, when the dredging is performed in the distant offshore fromouter breakwater. The wave field of the problem is considered to be 2D
plane and the configuration of the dredging region is designated by single
horizontal long-rectangular type. The numerical simulation is performed byusing the Green function based on the BIEM (Boundary Integral Element
Method). The results of the present numerical simulations are illustrated byapplying the normal incidence. It is shown that the ratios of wave height
reduction at the front face of breakwater are approximately 20% by theeffect of dredging on the sea bed. This study can effectively be utilized forsafety assessment to various breakwater systems in front of urban city near
the coastal area.

1. INTRODUCTION
To protect urban city of coastal area, many kinds of breakwaters have been
installed and extended. Nevertheless, the disaster has attacked to the coastal
region. This study is to investigate the reduction effect of wave height bydredging using the depth-discontinuity for the safe of coastal urban citybehind the breakwater. The early studies on the interaction of incident
waves with a dredge region has been investigated by Newman(1965),
Hilay(1969), Lee and Ayer(1981), Miles(1982), Kirby and Dalrymple(1983).
In all these researches, dredge region was assumed to be infinitely long andthe problem was restricted to the horizontal and vertical coordinates.
Later, Williams(1990) and McDougal et al.(1996) presented the numericalmodel for involving two horizontal plane in case of single or multiple pits.
3D(three dimensional) model, which is based on the Airy wave theory, wasinvestigated by Williams and Vazquez(1990) to analyze wave diffraction
through a single trench. However, all of these studies in above, attentions

501

October 2009, Incheon, Korea

were restrict to interaction for one or two aspects, which were occurred overpit(or trench) with discontinuity water depth.
The present study is about interaction of wave, which is propagated over pit
with discontinuity water depth, and investigates this wave affecting the fontface of breakwater and vicinity of coastal city. The wave interaction isconnected to three boundary problems, which are interaction of
discontinuity water depth and pit, discontinuity water depth within pit andbreakwater, and pit and breakwater. The problem is considered in a twodimensional plane, and the configuration of dredging region on sea bed is asingle-long rectangular type. The numerical simulation is performed byusing the solution of the boundary integral equation based on the Greenfunction.
In order to verify the present numerical model, comparison is made with theresults of absolute and approximation solution presented by Koji and
Mutsuo(1976) for regular wave diffraction at the front face of refracted
breakwater without pit. The decreasing effects of diffracted wave field in
vicinity of breakwater by dredging place with discontinuity water depth
were investigated. The present study can provide information to design
dredge line of the outer breakwater, and can effectively be utilized for safetyassessment to various breakwater systems in front of urban city near thecoastal area.

2. THEORETICAL DEVELOPMENT
The geometry of the problem is presented in figure 1 and figure 2. The
boundary regions express S1 (dredging boundary) and S 2 (breakwaterboundary, respectively. Figure 2 is configuration of trench and division ofregion at the CD line in figure 1. AA line in figure 1 represents the points ofwave diffraction investigated by present numerical model.

Figure 1: Layout of dredging region and breakwater systems.

502

New Technologies for Urban Safety of Mega Cities in Asia

The fluid region is taken to be inviscid and incompressible, and the flow
irrotational, then it will be assumed that the fluid motion may be describedin terms of a velocity potential φ ( x, y, z, t ) = Φ( x, y, z )e −iωt . This potential mustsatisfy Laplace’s equation, ∇ 2Φ = 0 . It is subject to the usual boundary
conditions on the free surface and seabed, and the solution of velocity
potential can be given flowing forms.
cosh[k1 ( z + d )]; Region 1
cosh(k1d )gacosh[k 2 ( z + h)]; Region 2f ( x, y )Φ 2 ( x, y , z ) =σ 2cosh(k 2 h)

Φ1 ( x, y, z ) =gaσ

f1 ( x, y )

(1)
(2)

where, a is incident wave amplitude, d is water depth within dredging
region, h is water depth of fluid region(vicinity of breakwater), f j ( j =1, 2)
is wave function, subscript 1 represents dredging region, subscript 2
represents region without dredging region, and the wave numbers k j ( j =1,
2) are defined byω 2 = gk1 tanh( k1d ); Region 1(3)ω 2 = gk 2 tanh( k 2 h ); Region 2(4)where ω is angular frequency and g is the gravitational acceleration.

Figure 2: Definition sketch of dredging region and boundary surfaces.
The wave function can be described as following form.
f ( x, y ) j = f i j ( x, y ) + f rj ( x, y ) + f s ( x, y )f i j ( x , y ) = −ie
f r j ( x , y ) = −ie

ik j ( x cos θ + y sin θ )ik j ( x cos θ − y sin θ )j =1, 2(5)

j =1, 2(6)

j =1, 2(7)

where f i is incident wave function, f r reflective wave function, and f s isscattered wave function. f s ( x , y ) should be satisfied by Helmholtz equation.

The Safety Assessment to Urban City of Coastal Area by Wave-Structure Interaction503

October 2009, Incheon, Korea

∂2 fs
∂x

2

+

∂2 fs
∂y

2

+ k j2 fs = 0

j =1, 2

(8)

Continuity of mass flux and pressure across the fluid interface between theinterior dredging region ( S1 ) and vicinity of breakwater region ( S 2 ) requires
the following conditions be satisfied there:
d

∂f 1
∂f
=h 2
∂n
∂n
Φ1 = Φ 2

j =1, 2

on S1

(9)

on S1

(10)

The boundary condition of vicinity of breakwater region without dredging
region are described as,∂f r2 ⎞⎛ ∂f i∂f∂f 2⎟= 0 , s = −⎜⎜ 2 +
⎟
∂n
∂
∂
n
n
∂n
⎝
⎠

on S 2(11)

The boundary condition each regions can be taken as eqn. (12) and (13)through ∂f1 / ∂n = 0 , ∂f 2 / ∂n = 0 and eqn. (9), respectively.
∂f sh ⎛ ∂f i ⎞=− ⎜ 1⎟∂nd ⎜⎝ ∂n ⎟⎠

on S1

(12)

∂f r ⎞∂f sh ⎛ ∂f i=− ⎜ 2 + 2 ⎟⎜d ⎝ ∂n∂n∂n ⎟⎠on S 2(13)

Finally, the scattered component of the fluid potential in the S 3 is subject toa radiation or far-field boundary condition at large radial distances r , which
may be written as
lim

r →∞

⎛ ∂f
⎞
r ⎜ s − ik j f s ⎟ = 0∂
r⎝⎠

j =1, 2

(14)

Applying Green’s second identity to f s ( x, y ) and extending to full regions( S1 + S 2 + S 3 ), boundary integral equations can be yielded as without
dredging region (eqn. (15)) and with dredging region (eqn. (16)),
respectively.
f s ( x, y ) = −

⎡
1
∂ ⎛ 1
⎞
(1)
⎜ − iH ( k 2 R ) ⎟⎢ f s (ξ , η ) ⋅2 S2 + S3 ⎣∂n ⎝ 2 0⎠∫⎤⎛ 1 (1)⎞ ∂− ⎜ − iH 0 (k 2 R) ⎟ ⋅f s (ξ ,η )⎥
⎝ 2
⎠ ∂n
⎦
f s ( x, y ) = −

504

(15)

⎡
1
∂ ⎛ 1
⎞
(1)
⎜ − iH ( k j R ) ⎟⎢ f s (ξ , η ) ⋅2 S1 + S 2 + S 3 ⎣∂n ⎝ 2 0⎠∫

New Technologies for Urban Safety of Mega Cities in Asia

⎤
⎛ 1
⎞ ∂
− ⎜ − iH 0(1) (k j R) ⎟ ⋅f s (ξ ,η )⎥
⎝ 2
⎠ ∂n
⎦

j =1, 2(16)

where, (ξ ,η ) is the coordinate of point on the boundary( S1 , S 2 ) and ( x, y) is
the coordinate of arbitrary point in the Region 1 and 2, n is the normal
direction to S , H 0(1) is the Hankel function of the first kind of order zero,
and R2 = (x − ξ )2 + ( y −η)2 . The scattered wave has no effect on the imaginary
boundary line ( S 3 ) and then f s ( x, y) = 0 on S 3 . Applying boundary
condition to eqn. (15) and (16) and considering reflection coefficient K r ,eqn. (15) and (16) becomef s ( x, y ) = −

⎡
1
∂ ⎛ 1
⎞
f s (ξ ,η ) ⋅ ⎜ − iH 0(1) ( k 2 R ) ⎟⎢2 S2 ⎣∂n ⎝ 2⎠∫∂f r ⎞⎤⎛ 1⎞ ⎛ ∂f i+ K r ⎜ − iH 0(1) (k 2 R) ⎟ ⋅ ⎜ 2 + 2 ⎟⎥ ds⎜∂n ⎟⎠⎥⎦⎝ 2⎠ ⎝ ∂nf s ( x, y ) = −
−

(17)

⎡
⎞ ⎛ ∂f i ⎞⎤∂ ⎛ 1
1
⎞ h ⎛ 1 (1)f s (ξ ,η ) ⋅ ⎜ − iH 0(1) ( k1 R ) ⎟ + ⎜ − iH 0 (k1 R) ⎟ ⋅ ⎜⎜ 1 ⎟⎟⎥ ds⎢
2 S1 ⎣∂n ⎝ 2⎠ ⎝ ∂n ⎠⎥⎦⎠ d⎝ 2∫⎡⎛ 1 (1)⎞ h ⎛ ∂f i2 ∂f r2 ⎞⎟⎤∂ ⎛ 1 (1)1⎞+
f s (ξ ,η ) ⋅⎥ ds⎜ − iH 0 ( k 2 R ) ⎟ + K r ⎜ − iH 0 (k 2 R) ⎟ ⋅ ⋅ ⎜⎜⎢∂n ⎟⎠⎦⎥
2 S2 ⎣∂n ⎝ 2⎝ 2⎠ d ⎝ ∂n⎠∫(18)
Approaching the coordinate of arbitrary point ( x, y) to the coordinate ofpoint (ξ ,η ) on the boundary( S1 , S2 ), the following integral equation can be
written as,
f s ( x, y ) = −

⎡

∂ ⎛

1

(1)

⎞

∫S ⎢⎣ f s (ξ ,η ) ⋅ ∂n ⎜⎝ − 2 iH 0 (k 2 R ) ⎟⎠2

∂f r ⎞⎤⎞ ⎛ ∂f i⎛ 1+ K r ⎜ − iH 0(1) (k 2 R) ⎟ ⋅ ⎜ 2 + 2 ⎟⎥ ds∂n ⎟⎠⎦⎥⎝ 2⎠ ⎜⎝ ∂nf s ( x, y ) = −

−

⎡

(19)

⎞ ⎛ ∂f i1 ⎞⎟⎤
⎡
(1)
∂ ⎛ 1
⎞ h⎛ 1f s (ξ ,η ) ⋅ ⎜ − iH 0(1) ( k1 R ) ⎟ + ⎜ − iH 0 (k1 R) ⎟ ⋅ ⎜⎜
⎥ ds
⎢
S1 ⎣
∂n ⎝ 2⎠ d⎝ 2⎠ ⎝ ∂n ⎟⎠⎦⎥

∫

∂ ⎛

1

(1)

⎞

⎛ 1

(1)

⎞ h ⎛ ∂f i2∂f r2 ⎞⎤∫S ⎢⎣ f s (ξ ,η ) ⋅ ∂n ⎜⎝ − 2 iH 0 (k 2 R ) ⎟⎠ + K r ⎜⎝ − 2 iH 0 (k 2 R) ⎟⎠ ⋅ d ⋅ ⎜⎜⎝ ∂n + ∂n ⎟⎟⎠⎥⎥⎦ds
2(20)
A diffraction coefficient of regular wave, K d is defined as
K d = f s ( x, y )(21)

3. NUMERICAL RESULTS AND ANALYSISThe Safety Assessment to Urban City of Coastal Area by Wave-Structure Interaction505

October 2009, Incheon, Korea

3.1 Validation of the numerical model.
A computer program has been developed to implement the above
theory for regular wave diffraction vicinity of breakwater by dredging on
the sea bed. The present numerical results have been investigated the
reduction of wave height at the front face of refracted breakwater bycomparing the absolute- and approximate solutions presented by Koji and
Mutsuo(1976). The present numerical model can be studied wave height
distributions at the vicinity of breakwater with dredging or without dredging,respectively. The conditions of calculation and configuration of refracted
breakwater in regular waves by Koji and Mutsuo(1976) are defined asincident wave angle θ = 45 o , angle of refracted breakwater β = 135 o ,reflection coefficient K r = 0.8 , and length of breakwater =2L, respectively.
Figure 3 shows a comparison of the results at the AB line(Fig. 1) for
the diffraction coefficient of regular waves at the front face of refracted
breakwater obtained by the present numerical model and those of Koji and
Mutsuo(1976).

Figure 3: Comparision of wave diffractions of present study with those of
approximate and absolute solutions.
In a comparison from Figure 3, it is noticed that the diffraction
coefficient at the front face of refracted breakwater by present numericalmodel is little bit higher than results of Koji and Mutsuo(1976), because
they performed at the infinite refracted breakwater. So, present numericalmodel have been performed at the finite refracted breakwater considering
phase difference and wave scattering by interaction between incident waves
and reflect wave, this study is more accurate than previously results.
3.2 Numerical examples
Numerical examples are presented to investigate the influences bydredging at the front face of refracted and straight breakwaters.
In this study, the condition of calculations are water depth in thevicinity of breakwater h = 7m , water depth within dredging region d = 14m ,and incident wave angle θ = 90 o for regular wave, respectively. Figure 4
presents the results for the diffraction coefficient obtained by the present

506

New Technologies for Urban Safety of Mega Cities in Asia

numerical model with and without dredging at the front face of refracted
and straight breakwater, respectively.

Figure 4: Wave height distributions at the front face of breakwater systems
with or without dredging.
For the case of refracted breakwater with a dredging at the offshore
sea bed as shown in Figure 4, the reduction of the relative wave height canbe observed right side of breakwater from refracted point. This reduction is
15.4% less than the numerical results for the case without dredging. For thecase of straight breakwater with a dredging, wave height is reduced all lineof breakwater. This reduction is 20.4% less than results without dredging.
Figure 5 presents the contours of the wave height near the breakwater
due to regular diffraction wave with two case of breakwater. From theresults a dredging pit may provide an excellent mean to protect from wave
attack. It can be seen that wave energy is weak by discontinuity water depth(dredging) and coastal city behind breakwater can be saved during stormy
season.

4. CONCLUSIONSThe present study is to estimate the decreasing effects of diffracted wave
fields around breakwater, for the case of dredging is performed at offshore
sea bed. This study is about to the compositive interaction for the threeproblems; dredging boundaries, depth discontinuity of dredging, andbreakwater boundaries. The boundary conditions are established for those
problems and applied to the boundary integral equation.

The Safety Assessment to Urban City of Coastal Area by Wave-Structure Interaction507

October 2009, Incheon, Korea

400

400

300

300

200

200

100

100

0

0

-100

-100

-200

-200

-300

-300

-200

-100

0

100

200

400

400

300

300

200

200

100

100

0

0

-100

-100

-200

-200

-200

-100

0

100

200

-200

-100

0

100

200

-300

-300
-200

-100

0

100

200

Figure 5: Contour plots of diffraction coefficients at the breakwater systems
with or without dredging.
Results for the incident wave conditions have been presented to illustrate thewave height distribution of the wave field of breakwater by dredging. A
dredging pit may protect from severe wave attack and it can be contributed
for the safety of coastal city by sever wave environment such as storm surge.
It is noticed that the results from the present numerical model accurately
provides the diffracted wave height of vicinity of breakwater systems, whendredging is performed at the offshore sea bed, and so may be extended toapply with confidence in harbor planning and design applications.

REFERENCES
Brown, A., 1997. How to format references. Unpublished report, NIWA,
Christchurch, New Zealand.
Davoren, A., and Mosley, M. P., 1986. Observations of bedload movement,bar development and sediment supply in the braided Ohau River. Earth
Surface Processes & Landforms 11, 643-652.

508

New Technologies for Urban Safety of Mega Cities in Asia

Mosley, M. P., 1979. Sediment sources in the Harper-Avoca Catchment.
Forest Research Technical Paper 68, New Zealand Forest Service,
Wellington.
Mosley, M. P., 1997. Motu River. In Jayawardena, A. W., Takeuchi, K., andMachbub, B. (editors), Catalogue of Rivers for Southeast Asia and thePacific, Vol 2, UNESCO-IHP Regional Steering Committee, Jakarta, 226235.
Schumm, S. A., Mosley, M. P., and Weaver, W. E., 1987. Experimental
geomorphology: the study of small landforms. John Wiley, New York.
Hilaly, N., 1969. Water waves over a rectangular channel though a reef.
Journal of Waterways and Harbor Division, ASCE, 95(1):77-94.
Kirby, J.T. and Dalrymple, R.A., 1983. Propagation of obliquely incident
water waves over a trench. Journal of Fluid Mechanics, 133, 47-63.
Koji, K. and Mutsuo, O. 1976. A study of wave height distribution along a
breakwater with a corner. Report of the Port & Harbor Research Institute,15(2), 55-88.
Lee, J.J. and Ayer, R.M., 1981. Wave propagation over a rectangular trench.
Journal of Fluid Mechanics, 110, 335-347.
McDougal, W.G., Williams, A.N. and Furukawa, K., 1996. Multiple-pit
breakwaters. Journal of Waterway, Port, Coastal and Ocean Engineering,
ASCE, 122(1), 27-33.
Miles, J.W., 1982. On surface wave diffraction by a trench. Journal of Fluid
Mechanics,115, 315-25.
Newman, J.N., 1965. Propagation of water waves over an infinite step.
Journal of Fluid Mechanics, 23, 399-415.
Williams, A.N., 1990. Diffraction of long waves by rectangular pit. Journalof Waterway, Port, Coastal and Ocean Engineering, ASCE, 116(4), 459-469.
Williams, A.N. and Vazquez, J.H., 1991. Wave interaction with arectangular pit. Journal of Offshore Mechanics and Arctic Engineering, 113,
193-198.

The Safety Assessment to Urban City of Coastal Area by Wave-Structure Interaction

509

PARALLEL SESSION 8

ANALYZING IMPACTS OF SEA LEVELRISE ON COASTAL CITIES WITH FOCUS
ON FLOODS AND SALINITY FLUX
MD. JABED ABDUL NASER BHUIYAN AND DUSHMANTA DUTTA
Monash University, Churchill, VIC 3842, Australia
Dushmanta.Dutta@sci.monash.edu.au

ABSTRACT
Coastal zones are particularly vulnerable to climate variability andchange. In the last century, sea level rose on average 10-12cm per decadeand in much higher rates in some coasts due to land subsidence. The 4th
IPCC report highlights the increased vulnerability of the coastal urban
areas around the world due to sea level rise in 21st Century. Key concerns
due to sea level rise include flooding and salinity and its implications forwater resources. Rising sea level increases the salinity of both surface waterand ground water through salt water intrusion.
It is important to determine the impacts of sea level rise on flooding
and salinity to devise suitable adaptation and mitigation measures to reduce
impacts of floods and salinity intrusion in coastal cities. The paper presents
the outcomes of a study conducted in the coastal area of Gorai river basinin the south west Bangladesh for developing a comprehensive
understanding of the possible effects of sea level rise with the aid ofhydrodynamic modelling. A newly developed salinity flux model was
integrated with an existing hydrodynamic model to simulate floods andsalinity in the complex waterways in the coastal zone of Gorai river basin.
The model was applied under a range of future scenarios and the results
indicate both spatial variability of risk and changes in flood and salinity
characteristics between now and under sea level rise scenarios.

1. INTRODUCTION
Coastal and shallow marine regions are among the most productive systems
in the world (Mann, 1988; Glantz, 1992). The Intergovernmental Panel on
Climate Change (IPCC) in its fourth assessment report presents someobservational evidences of climate change in the coastal region. Some of theevidences are increased ocean temperatures, changes in precipitation
amounts and corresponding upstream river discharge, rising sea level,
increased flooding and inundation etc.
Flood magnitudes and frequencies will very likely increase in most regions— mainly as a result of increased precipitation intensity and variability —511

October 2009, Incheon, Korea

and increasing temperatures are expected to intensify the climate'shydrologic cycle and melt snowpacks more rapidly (IPCC, 2007). Flooding
can affect water quality, as large volumes of water can transport
contaminants into water bodies and also increase transport throughoverloaded storm and wastewater systems. The lives of human beings andaquatic life are greatly dependant on the availability of fresh water and sea
level rise can change the availability and distribution of fresh water. The
water quality is a current problem in the coastal zone which is expected to
be exacerbated by climate change and sea level rise. Sea level rise may also
affect freshwater quality by increasing the salinity of coastal rivers and bays
and causing saltwater intrusion, movement of saline water into fresh groundwater resources in coastal regions resulting in decreasing water quality(Bashar and Hossain, 2006). Sea level rise may cause saline intrusion into
the land and larger or more frequent storm surges may impact salinity incoastal zone. It would be more acute in the dry season, especially whenfreshwater flowing from rivers has diminished. Salinity intrusion due toreduction of freshwater flow from upstream, salinisation of groundwater andfluctuation of soil salinity are major factors and concerns. In Bangladesh thecauses behind water quality deterioration in coastal areas are: climatechange and sea level rise, decrease of upstream flow due to the Farakka
Barrage in India, expansion of shrimp farms and Coastal Embankment
Project, implemented during the 1960s. Coasts will be exposed to increasing
risk, including coastal erosion due to sea level rise. The impact isexacerbated by increasing human-induced pressures (Nicholls et al., 2007).
The impacts of salinity are: more land will be salinity-affected and theintensity of the salinity effect will be increased, decreased productivity ofagricultural land, increased food insecurity as naturally growing species
disappear, serious scarcity of safe drinking water, loss of biodiversity, e.g.
decrease in tree species and freshwater fish and socioeconomic problems,
generally women are more vulnerable. There is clear evidence of increased
saline intrusion in the coastal zones. For example in Bangladesh, in the
coastal city of Khulna the main power station uses fresh water to cool its
boilers by sending a barge upstream to get fresh water. Over the last one
decade the barge has had to go further and further upstream to get suitablefresh water for the purpose (NAPA, 2005). Increased salinity intrusion due
to sea level rise poses a great threat to the Sundarban forest. The Sundarban
has already been affected due to reduced freshwater flowing through theGanges river system over the last few decades particularly during the dry
season. This has led to a definite inward intrusion of the salinity front
causing various species of plants and animals to be adversely affected.
Increased salt water intrusion is considered as one of the causes of top dyingof Sundari trees.
Computer based mathematical model is now a well recognized tool for
simulating these complex problems. Mathematical modeling has been
carried out for more than three decades (Dutta, 1999). Growing needs ofmathematical model made to improve its quality and technique. Traditional
lumped conceptual type models cannot rightfully be claimed to be

512

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Fluxscientifically sound (Klemes, 1988). The study aims to develop acomprehensive understanding of the sea level rise impact on coastal water
quality with the aid of mathematical model. The objective of the study is todevelop a salinity flux model and integrate with an existing hydrodynamic
model. Then the integrated model is used to assess the impact of sea level
rise on flooding and salinity in the coastal zone.

2. STUDY AREA AND SALINITY INTRUSION
2.1

Location and Geophysical Environment

The model was applied to simulate flood event and salinity intrusionin the Gorai river basin located on the South West region of Bangladesh.
Salinity intrusion is a major concern in this area as the rivers are tidal andsea salinity intrusion in these rivers is a major issue. The study area
comprises an area of 32,280 sq. km between latitude 21˚30’ N to 24˚00’ N
and longitude 88˚50’ E to 90˚10’ E. The annual average rainfall is 1,700mm/year (ADB, 2005). The area is bounded by Ganges River in the north,tributaries from Meghna River in the east, international boundary in thewest and the Bay of Bengal in the south (Fig. 1). The topography of theregion is rather flat, and gently sloping towards the Bay of Bengal. Most of
the area is protected with polders against river flooding. The downstream
part of the area is covered with Sundarban forest.

Figure 1: South western part of Bangladesh

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux513

October 2009, Incheon, Korea

2.2 Coastal flooding and Salinity Intrusion
The coastal zone is particularly vulnerable to flooding due to its lowlying lands and very poor defenses against flooding. Salinity intrusion in theriver system downstream of the study area has been an issue. The GoraiMadhumati River, a Ganges tributary, reduces its flow during the dry season.
Due to the reduced flow of these rivers during the dry season, salinity
intrudes into the river systems.

3. METHOD OF SIMULATION
3.1 Hydrodynamic Model
The hydrodynamic (HD) model was originally developed at the PublicWork Research Institute (PWRI) of Japan (Yoshimoto et al., 1992). The
model has two major components: a one dimensional river flow component
and a two dimensional floodplain component. The main characteristic of themodel is the coupling between the river and floodplain components anddynamic flow exchange through the links. The flow exchange between theriver and floodplain may occur for various scenarios such as levee failure or
overtopping, flow through structures such as pump or sluice gate, etc. Points
and extent of flood levee failure is governed by the water level in the riverand the height of levee through the use of unsteady flow calculation in theriver. The model uses the one dimensional unsteady dynamic wave form of
St Venant’s equation for river flow simulation and two dimensional
unsteady equations for floodplain flow. These equations are derived using
explicit solution scheme from the continuity and momentum equations(Dutta et al., 2007). The river nodes and floodplain grids are linked throughsuitable conceptual equations representing different conditions of flow
exchange.
3.2 Development of River Salinity Transport Model
A salinity transport model has been developed as part of this study toinvestigate transport processes within the entrance of a coastal lagoon
through estimating the advection dispersion coefficients and integrated withthe existing hydrodynamic model. Both the models work in FORTRAN
environment.
The transport and dispersion of solute in the longitudinal case involves
a mathematical representation in the form of the following single
dimensional, partial differential equation (Fischer et al., 1979; Orlob, 1983;
Henderson Sellars et al., 1990; Young and Wallis, 1992), usually known by
Fickian Diffusion Equation or Advection Dispersion Equation (ADE),∂x( s, t )∂x( s, t )∂ 2 x ( s, t )
+U
=D
∂t
∂s
∂s 2

514

(1)

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux

where, x(s,t) is the concentration of the solute at spatial location s andtime t; U is the cross-sectional average longitudinal velocity; and D is thelongitudinal dispersion coefficient.
The distance-time (x-t) planes for formulating explicit finite difference
schemes of advection dispersion equation is shown in figure 2.

Figure 2: Distance-time plane used in the solution scheme of salinity model
In this equation, water is considered to be completely mixed over the
cross-sections and the dispersive transport is proportional to theconcentration gradient
3.3 Model Setup and Calibration
The model setup includes the calibration and verification. The total
number of square grid is 129,120 with 500 m resolution. The existing polder
heights have been added with the topography to represent the river bankprotection. For river network, the Gorai river and its tributaries are
considered. Daily discharges at Gorai Railway Bridge and Garaganj stations
are used as upstream boundary and three hourly water level data at
Charduani, Hironpoint and downstream point of Malancha are used as
downstream boundary. Daily rainfalls at 24 gauging stations are used asinternal runoff. No lateral overland flow is considered. The river network
data included cross-sections at every 500 m interval between Gorai Railway
Bridge and Bay of Bengal. Roughness coefficients for rivers and surface
were estimated on the basis of the land use types (Dutta et al., 2009).
For the salinity model, freshwater salinity is considered as the
upstream boundary (0.5 ppt). Observed salinity at Katka (Betmar Gang
River), Hironpoint (Nilkamal River) and Dobaki South (Arpangasia River)
have been used as downstream boundary. All the necessary data for HD andsalinity model have been collected from the Institute of Water Modelling(IWM).
The hydrodynamic model has been calibrated and verified for two
events of the year 2002. The calibrated parameter is manning’s roughness in
the river. Calibration and verification was performed using the water level

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux

515

October 2009, Incheon, Korea

data at some selected stations. Dry period flow during the month of April
and May in the year 2002 has been used for calibration. The roughness
coefficients were adjusted by trial and error. The coefficients were found to
be within 0.015-0.035. Figure 3 shows the comparisons of simulated waterlevel at Kamarkhali and Patgati with the observed data where the waterlevels are measured based on the datum of the Public Works Department(PWD). The PWD datum is 0.46 m lower than the mean sea level(Tingsanchali and Karim 2005).

Figure 3: Water level comparisons at Kamarkhali and Patgati incalibration
For verification of the model parameter, wet season flow during themonth of July and August has been considered in the year 2002. Figure 4
shows the comparisons of water level at Kamarkhali and Patgati.

Figure 4: Water level comparisons at Kamarkhali and Patgati inverification
The model performance was determined based on mean andcoefficient of determination (R2). The computed mean value at Patgati and
Pirojpur were found to be almost the same as the observed mean values,
with a variation of +6% and +9% respectively. The R2 values between theobserved and computed hydrograph of water level were found to vary
within 0.81 to 0.91, while this value should be 1 for perfect agreement. The
scatter plots of observed and simulated water level at Kamarkhali andPatgati stations have been shown in the figure 5.

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Figure 5: Scatter plots of observed and simulated water level at Kamarkhali
and Patgati
The summarized results from the statistical analysis of water level
data are shown in Table 1.
Table 1: Summarized results of water level data analysis
Mean water level (meter Coefficient of
Station Name above PWD datum)
determination(R2)
Computed
Observed
Kamarkhali
1.83
1.68
0.91
Patgati
1.27
1.35
0.81
The salinity model has been calibrated by systematically adjustingvalues of selected system parameter to achieve an acceptable match between
measured salinity and salinity with corresponding values predicted by the
one dimensional advection dispersion model (Gates et al,. 2002). The
calibration parameter is the dispersion coefficient in the river which was
adjusted by trial and error. Figure 6 shows the comparison of observed andsimulated salinity at Mongla station where the unit is parts per thousand(ppt).

Figure 6: Salinity comparison at Mongla in calibration

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux517

October 2009, Incheon, Korea

4. IMPACT ANALYSIS
4.1 Flooding Extent
To analyze the effects of sea level rising, the sea level is raised by 59
cm in the hydrodynamic model to simulate flood at the end of 21st century.
The depth of flooding in each grid was calculated by subtracting land
elevation from the computed flood level. This methodology is similar to that
described in the Manual of Economic and Social Commission for Asia andthe Pacific (ESCAP, 1991). The flooded area was classified into four hazard
categories based on three critical depths, 0.6, 1.0 and 3.5 m. Similar type ofclassification has been used in Tingsanchali & Karim (2005). The basis of
selecting critical depths is briefly described herein. In general, plinth level
above the ground is 0.6 m in school buildings, community centers andpublic buildings. In case of flood depths of more than 1.0 m, there is apossibility of death, and huge damage to agricultural production is expected.
The minimum height of sills for shelters and also for one-storey buildings is
usually 3.5 m. Typical flood maps without and with 59 cm SLR has beenshown in Fig. 7. The flooded areas under different depth categories havealso been summarized in table 2.

Figure 7: Simulated flood extent map without and with 59 cm SLR
Table 2: Computed flooded area under different depth category
Depth of Flooded area (sq. km)
Depthflooding
Present
With 59 cm Increase
Category(m)condition
SLR
(%)
1
< 0.6
1146
1817
59
2
0.6 - 1.0
386
582.5
51
3
1.0 - 3.5
36
46.5
29
4
> 3.5
160.5
161
0.3

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4.2 Salinity Increase
Due to sea level rise, the changes in maximum salinity at different
stations have been shown in the following table (Table 3).
Table 3: Changes in maximum salinity due to 59 cm SLR
Present
With 59 cm Salinity
Name of Station
condition (ppt) SLR (ppt)
Increase (ppt)
Mongla
14.9
15.7
0.8
Nalianala
16.3
17.0
0.7
The intrusion of salinity in the Passur river for 5 ppt and 10 ppt
concentration has been simulated from the salinity model which has beensummarized in the following table (Table 4);
Table 4: Salinity intrusion length in Passur river
Salinity front line Salinity
intrusion(ppt)
length (km)
5
25.2
10
7.1

5. CONCLUSION
The sea level rise impact on coastal flooding and salinity increase has been
estimated with an integrated hydrodynamic and salinity model. The study
analyzed the impact in terms of flooding depth and extension, changes insalinity concentration and salinity intrusion. The results shows if Sea level isrised by 59 cm, the flooding depth below 0.6 m will be increased by morethan 50% and 5 ppt salinity front will move about 25 km upstream. Suchdetailed impact assessment can be effectively used by planners and decision
makers for adaptation to climate change in the highly vulnerable coastal
areas of Gorai river basin. The model can be applied in other study area toquantify the changes in salinity due to climate change and salinity intrusion
through the river.

REFERENCES
ADB, 2005. Southwest Area Integrated Water Resources Planning andManagement Project in Bangladesh, Asian Development Bank.
Bashar, K. E. & Hossain, M. A., 2006. Impact of Sea Level Rise on Salinityof Coastal Area of Bangladesh. 9th International River Symposium.
Brisbane, Australia.
Dutta, D. & Nakayama, K. 2009. Effects of Spatial Grid Resolution on River
Flow and Surface Inundation Simulation by Physically Based Distributed
Modelling Approach. Hydrological Processes, 23, 534-545.
Dutta, D., Alam, J., Umeda, K., Hayashi, M. & Hironaka, S., 2007. A twodimensional hydrodynamic model for flood inundation simulation: a case

Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux519

October 2009, Incheon, Korea

study in the lower Mekong river basin. Hydrological Processes 21: 12231237.
Dutta, D., 1999. Distributed modeling of flood inundation and damage
estimation. University of Tokyo. Doctor of Engineering: 168.
ESCAP, 1991. Manual and Guidelines for Comprehensive Flood Loss
Prevention and Management. Bangkok, Economic and Social Commission
for Asia and the Pacific.
Fisher, P., Abrahart, R. J. & Herbinger, W., 1997. The sensitivity of two
distributed non-point source pollution models to the spatial arrangement of
the landscape. Hydrological Processes 11: 241-252.
Gates, T. K., ASCE, M., Burkhalter, J. P., ASCE, M., Labadie, J. W., ASCE,
M., Valliant, J. C. & Broner, I., 2002. Monitoring and Modeling Flow andSalt Transport in a Salinity-Threatened Irrigated Valley. Journal of
Irrigation and Drainage Engineering, 128, 87-99.
Glantz, M.H., 1992. Climate Variability, Climate Change, and Fisheries.
Cambridge University Press, New York, 450 pp.
Henderson-Sellars, B., Young, P. C., and Ribeiro da Costa, J., 1990. Water
quality models: rivers and reservoirs, in Proc. 1988 Int. Symp. on Water
Quality Modelling of Agricultural Non-Point Sources; US Agriculture Dept,
Agricultural Research Service; 1990; Publication No. ARS-81, 381-420.
IPCC, 2007. Climate Change Impacts, Adaptation and Vulnerability. Fourth
assessment report of the Intergovernmental Panel on Climate Change.
Klemes, V., 1988. A Hydrological Perspective. Journal of Hydrology, 100,
3-28.
Mann, K.H., 1988. Production and use of detritus in various freshwater,
estuarine and coastal marine ecosystems. Limnology and Oceanography 33,
910-930.
NAPA (Bangladesh), 2005. Formulation of Bangladesh Program of Action
for Adaptation to Climate Change Project.
Nicholls, R. J., Wong, P. P., Burkett, V. R., Codignotto, J. O., Hay, J. E.,
McLean, R. F., Ragoonaden, S. & Woodroffe, C. D., 2007. Coastal systems
and low-lying areas. Climate change 2007: Impacts, Adaptation and
Vulnerability. Contribution of Working Group II to the Fourth Assessment
Report of the Intergovernmental Panel on Climate Change, M. L. Parry, O.
F. Canziani, J. P. Palutikof, P. J. van der Linden and C. E. Hanson, Eds.,
Cambridge University Press, Cambridge, UK, 315-356.
Orlob, G. T. (ed.), 1983. Mathematical Modelling of Water Quality:
Streams, Lakes and Reservoirs. J. Wiley, Chichester.
Tingsanchali, T. and M. F. Karim, 2005. Flood Hazard and Risk Analysis in
the Southwest Region of Bangladesh. Hydrological Processes 19(10): 20552069.
Yoshimoto, T., Fueda, T., Ikeda, Y. & Kawakami, T., 1992. Flood
Simulation of Two Dimensional Unsteady Flood Model. Technical
Memorandum of Public Work Research Institute (PWRI). Japan, T. M. of
PWRI No. 3105, ISSN 0386-5878, Public Works Research Institute.
Young, P.C., and Wallis, S.G., 1992. Solute transport and dispersion inchannels, forthcoming in: K.J. Beven and M.J. Kirby (eds), Channel
Networks, J. Wiley, Chichester.

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Analyzing Impacts of Sea Level Rise on Coastal Cities with Focus on Floods and Salinity Flux

INTEGRATED PLAN FOR FLOOD DISASTER
MANAGEMENT BY CLIMATE CHANGESKEEOH SHIM, BYUNGTAE YOO and KYUNGHO PARKNational Institute for Disaster Prevention, NEMA, Rep. of Korea
shimko, procsys, kh302@nema.go.kr

ABSTRACTThis research examined and presented the research tasks to bepromoted in an effort to prevent disasters centered on the current work of
the National Emergency Management Agency (NEMA) in terms of storm
and flood damage so that damage due to natural disaster caused by climatechange can be minimized. To explore the areas from the research aspect
related to policy, this research presented the research tasks that can preventor minimize damage caused by climate change as part of presenting
NEMA's comprehensive plan pertaining to climate change by maintaining
and developing the work promoted by NEMA based on the causes of andcountermeasures for recent damage caused by natural disaster.
To determine the status of damage of such major facilities, thisresearch collected and analyzed various damage survey reports, research
reports and journal articles discussing the status, and cause analyses andcountermeasures against damage caused by large-scale storm and floodrelated disasters. Based on the collected data, this research classified andanalyzed damages, causes, and countermeasures related to each of the
facilities damaged by natural disaster. This research selected and presented
48 research tasks on climate change to be promoted by work in relation to
NEMA's major work concerning storm and flood damage.

1. INTRODUCTION
As the average of global temperature continuously rises, climate change due
to global warming causes unforeseeable and extreme meteorologicalchanges such as heavy rainfall, typhoon, drought, and lightning. All thesedisasters are caused by the disruption of the water circulation system on
earth by melting iceberg in the polar regions.
As the sea level rises due to the melting iceberg or swelling seawater
caused by the rising temperature, the rising level of seawater stood at
0.20cm/year in 2000, compared to 0.07cm/year in 1990 in the East Sea. In
the West Sea, the rising level of sea level was also 0.20cm/year in 2000,
compared to 0.14cm/year in 1990. On the other hand, in the South Sea, therising rate of sea level stood at 0.34cm/year in 2000, compared to
0.32cm/year in 1990.
In other words, the average of the rising level of seawater wasobserved to increase in 2000, compared to 1990.

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To explore the areas from the research aspect related to policy, thisresearch presented the research tasks that can prevent or minimize damage
caused by climate change as part of presenting NEMA's comprehensive
plan pertaining to climate change by maintaining and developing the work
promoted by NEMA based on the causes and countermeasures for recent
damage caused by natural disasters.
To determine the status of damage of such major facilities, thisresearch collected and analyzed various damage survey reports, research
reports and journal articles discussing the status, and cause analyses andcountermeasures against damage caused by large-scale storm and floodrelated disasters. Based on the collected data, this research classified andanalyzed damages, causes, and countermeasures related to each of the
facilities damaged by natural disaster.
This research examined and presented the research tasks to bepromoted in an effort to prevent disasters centered on the current work of
the National Emergency Management Agency (NEMA) in terms of storm
and flood damage so that damage due to natural disaster caused by climatechange can be minimized.

2. VULNERABILITY
FACILITIESANALYSISOFDISASTERCONTROLAs the population increases, bridges are built to cross rivers, and tunnels areconstructed to address the inconvenience of climbing mountains. Note,however, that damages to those facilities built for man's convenience are on
the rise each year as typhoon and heavy rainfall become stronger due toclimate change. To minimize damages caused by natural disasters,presenting disaster prevention measures for coping with climate change aswell as identifying the status and causes of damage are essential.
2.1 Amount of Damage to Facilities
This research used data from annual disaster reports according tofacilities such as river, road, and farmland from 1977 to 2006 to minimize
damages caused by disaster. In consolidating data, the amount of damage
was categorized into the average damage amount for the last 10, 20, and 30
years.
Korea's damage amount according to facilities is ranked as follows:
rivers/streams, roads, irrigation, farmland, erosion control work, militaryfacilities, buildings, water channel, harbors, railways, ships, and schools.
2.2 Damage Status and Countermeasures according to Facilities
2.2.1 River/Stream Facilities
Korean peninsula is surrounded by the sea except the northern side;
hence its oceanic climate. Therefore, damages caused by torrential rain are
actually concentrated in summer, due mainly to the impacts of heavy
rainfall and typhoon during summertime. Damages to rivers caused by522

New Technologies for Urban Safety of Mega Cities in Asia

torrential rain and typhoon cause various types of damages to the rivers. As
such, damage cause analysis and countermeasures for preventing therecurrence of the damages were presented. We gathered storm and flood
damage reports related to climate change as examined and analyzed byvarious on-site disaster reports.
2.2.2 Road Facilities
Damages caused by torrential rain and typhoon give rise to various
types of damages to road facilities. In this context, damage cause analysis
and countermeasures to prevent the recurrence of damage were presented inrelation to road facilities including bridges. In this research, parts related toroad facilities damage in various on-site disaster reports and journal articles
dealing with storm and flood damage are extracted and consolidated.
2.2.3 Irrigation Facilities
Irrigation facilities in annual disaster reports referred to those related
to farmland, such as reservoir. Interest in irrigation facilities related tofarmland is huge, since farmers' attachment to land is strong considering thefact that Korea developed as an agricultural country. Damages to irrigation
facilities caused by torrential rain and typhoon as a result of climate change
cause various types of damages to irrigation facilities. Thus, damage cause
analysis and countermeasures for preventing the recurrence of the damages
that were presented. In this research, parts dealing with disaster caused byclimate change in various on-site disaster reports dealing with irrigation
facilities were extracted and arranged.
2.2.4 Farmland
Koreans' interest in farmland is huge, since farmers' attachment toland is strong, considering the fact that Korea developed as an agriculturalcountry. Damages to farmland caused by torrential rain and typhoon as aresult of climate changes, cause various types of damages to farmland. Thus,
damage cause analysis and countermeasures for preventing the recurrenceof the damages were presented. By examining and analyzing various on-site
disaster reports dealing with farmland, this research extracted andconsolidated parts dealing with disaster caused by climate change.
2.2.5 Erosion Control WorkAs the strength of heavy rainfall and typhoon increases due mainly to
climate change, damage to erosion control work caused by heavy rainfall
and typhoon, comes in various forms. Thus, damage cause analysis andcountermeasures for preventing the recurrence of the damages were
presented. By examining and analyzing various on-site disaster reports
dealing with erosion control work, this research extracted and consolidated
parts dealing with disaster caused by climate change.

3. COMPREHENSIVE PLAN ACCORDING TO MEASURES FORPREVENTING DAMAGES

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October 2009, Incheon, Korea

For the tasks in the relevant research field, the work carried out by NEMA
was identified and classified according to the criterion of relevance to thework. Toward this end, this research presented the details of the major workon storm and flood damage as performed by NEMA.
3.1 Presentation of Major Work Area
Measures for addressing the presented storm and flood damage basedon the damage status and cause analysis in the reports and publishedmanuscripts were selected as research area. The areas of major work carriedout by NEMA based on storm and flood damage including the Natural
Disaster Countermeasure Act are presented below.
- Rainwater runoff reduction facilities- Consultation on pre-disaster impact review- Natural disaster risk zone
- Comprehensive plan for reducing storm and flood damage- Establishment and operation of flood control criteria for facilities- Establishment and operation of flood control criteria for undergroundspace- Establishment of storm resistance design criteria- Insurance for storm and flood damage
3.2 Presentation of Comprehensive Plan by Area
In presenting the comprehensive plan for countering storm and flood
damage, this research classified related research tasks drawn from damage
countermeasures by work area based on the areas of major work carried out
and presented by NEMA.
3.2.1 Rainwater Runoff Reduction Facilities○ Development of rainwater runoff reduction facilities: new rainwaterrunoff reduction facilities need to be developed through continuous
research.
○ Development of runoff amount reduction criteria by basin : To reduce thepeak runoff amount in relation to increasing runoff due mainly to climatechange, the runoff amount may be reduced by causing rainwater toinfiltrate underground during rain. There is a need to introduce thecriteria for rainwater runoff reduction by basin and apply such as a pilot
project by setting the runoff amount by basin to be reduced during rain.
○ Development of criteria for the establishment of rainwater runoff
reduction facilities : The developed rainwater runoff reduction facilities
are generally burdensome from an economic point of view; hence theneed for the installation of rainwater runoff reduction facilities based on
certain criteria when undertaking a development project. When a subject
project installs facilities meeting the installation criteria, the developmentof various incentives and evaluation criteria based on which runoff
reduction capability can be evaluated is considered necessary. In
developing the installation criteria, the introduction of the charge system

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against projects generating a runoff amount beyond the appropriate
amount is a worthwhile research area.
3.2.2 Consultation System for Pre-Disaster Impact Review○ Disaster reduction area considering the development project's
characteristics: Research tasks are promoted as follows to achieve thegoal of implementing the system by analyzing the characteristics of thesubject projects for consultation on pre-disaster impact.
3.2.3 Natural Disaster Risk Zone Control○ Natural disaster risk zone criteria: Various risks can be managed by
improving the type categorization of natural disaster risk zones into 6
through the amendment of the Enforcement Ordinance of the Natural
Disaster Countermeasure Act. In designating natural disaster risk zones,
there is a need for the central government to use the budget impartiallythrough objective and common decision criteria.
○ Perceived area of natural disaster risk zone : Gradual improvement is
promoted by categorizing natural disaster risk zones into 6 types. Note,however, that damage should be prevented by arousing consciousness on
those zones through the education and promotion of local residents'
perception of those zones to avoid damages.
○ Extension of natural disaster risk zone types : Natural disaster risk zones
come in 6 types, but there is a need to expand the existing 6 types due tothe diversification of disaster types as a result of the recent climatechange; hence the need for the expansion of the selection of disaster types.
3.2.4 Comprehensive Plan for Reducing Storm and Flood Damage○ Flood disaster : Disaster risk evaluation is needed, since the rainfall phasediffers as a result of climate change. Determining the flood disaster risk
requires evaluating the risk of areas adjacent to rivers and determining theinundation risk on the densely populated low land area.
○ Slope collapse : The need to suggest countermeasures against a region
with landslide risk is raised by assessing the landslide risk stemming fromrainfall concentration and vegetation change of mountains and forests due
to climate change. Toward this end, there is a need to analyze areas withlandslide risk associated with climate change using GIS and forecast
those areas with landslide risk based on the analysis results.
○ Earth and sand runoff : The earth and sand runoff amount increases as thetorrential rain's frequency rises as a result of climate change. The runoff
earth and sand are deposited on the river bed, reducing water flow
capability, which in turn may cause flood damage owing to insufficientwater flow capability in case of flood.
○ Damage due to wind : Although climate change may reduce the frequencyof typhoon, the size of typhoon increases; thus possibly causing hugecasualties and property damage. Such damage is believed to be
attributable to the increase in the maximum instantaneous speed of thewind.

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3.2.5 Establishment and Operation of Flood Control Criteria for
Facilities○ Maintenance of design criteria for river and stream facilities : Uniformly
deciding the design frequency of river facilities is not advisable; theimpacts of urbanization within the basin and the importance of the riverneed to be considered; ditto for the evaluation of the impact of disasterrisk associated with climate change. In this context, systematic
supplementation and maintenance should be carried out by conducting
continuous research in relation to the design frequency of river facilities.
○ Reinforcement of sewerage facilities-related criteria : The frequency ofthe planned rainfall amount exclusion plan of the sewerage facilities
criteria should be upgraded considering the recent precipitation trend.
This is because the existing design criteria may not be able to cope withthe recent torrential rain or typhoon.
○ Maintenance and supplementation of agricultural production
infrastructure (reservoir, etc.) : A reservoir among the agricultural
production infrastructure is an effective means of securing the wateramount; over 30,000 facilities including small reservoirs are built in
Korea. The maintenance and supplementation of reservoir facilities are
truly necessary to make them function smoothly.
3.2.6 Establishment and Operation for Underground Space○ Introduction of flood control criteria for underground space : There is aneed to decide continually whether the flood control criteria forunderground space are appropriate through the investigation andexamination of inundation risk of underground facilities by categorizing
those structures where inundation damages often occur due to urbanizedarea flood and by estimating the areas to be surveyed for inundation by
structure; examining the criteria for the design and inundation measuresof advanced countries and introducing them to Korea are also essential.
○ System to cope with the inundation of underground space : When
subways, underground malls, underground driveways, and common
underground openings are flooded, an information system-based systemshould be established to cope with such inundation. Such system shouldbe able to identify situation information in real time and determine thepredicted inundation scale promptly. Ultimately, a comprehensive
disaster prevention system for underground space needs to be built todisseminate situation information quickly, secure safer evacuation access,and minimize casualties.
○ Evacuation system in case of underground space inundation : Considering
the underground space features, there can be restrictions in evacuation
owing to the obstacles in the course of evacuation. Moreover, since there
are few temporarily safe places before evacuating to a ground-level areain the case of flooding, large-scale casualties may occur due to sudden
flood or inundation; hence the need for the establishment of an evacuation
system for underground space and periodic education/training of local
residents to reduce casualties.

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New Technologies for Urban Safety of Mega Cities in Asia

3.2.7 Establishment of Storm Resistance Design Criteria○ Correction of basic wind velocity and evaluation method development :Although the value of the basic average wind velocity has been
determined in Korea, disasters are not appropriately forecast due to thelack of related criteria for various facilities. The reasonable evaluation
and adjustment of the basic wind velocity require the establishment ofwind velocity DB and evaluation technology on the wind environment.
○ Reinforcement of design criteria to cope with abnormal wind damage :Although there may be numerous types of national infrastructure facilities
for considering wind load, the load calculation criteria applied to various
facilities are not unified. As a result, different criteria are applied. Storm
resistance design can be optimized by applying unified criteria to various
facilities and by securing safety beyond a certain level at the national
level. The technical level should be improved through complementation
between technical levels.
3.2.8 Insurance for Storm and Flood Damage○ Expansion of the relevant products and enhancement of efficiency ofdamage assessment : The operating system should be decentralized andadjusted to expand the insured items and to avoid the duplication of
insurance products. For the efficient management of insurance for storm
and flood damage, an integrated management system for damage
appraisal and sales should be prepared. A system for rate calculation
should also be established through close monitoring.
○ Establishment of an agency exclusively in charge of insurance : For thesystematic operation and management of the dispersed insurance system
for storm and flood damage, an agency exclusively in charge of insurance
is necessary through work adjustment with the relevant institutions. In
relation to the introduction of a national reinsurance fund, reviewing theestablishment of the abovementioned integrated agency is essential since
the insurance market for storm and flood damage is not big enough tointroduce each governmental ministry's national re-insurance fund.

4. CONCLUSIONS
Climate on earth has changed alongside the development of civilization.
Thus, the average damage of the various facilities caused by heavy rainfall,
typhoon, and drought is increasing. As such, now is the time to makesincere efforts to minimize damages. Although people have made such
efforts a long time ago, voices clamoring for the restoration of damaged
facilities have mostly died down every time they clashed with economic
logic.
Many research tasks in various areas as presented in this research are
expected to be helpful to the work development of NEMA in connection
with financial source acquisition for future research. The final results in thisreport are presented below.
First, whereas Korea used to be passive in coping with climate change,
now, it is actively coping with it by establishing the Countermeasure
Planning Organization Against Climate Change affiliated with the Prime

Integrated Plan for Flood Disaster Management by Climate Changes

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October 2009, Incheon, Korea

Minister's Office after Myung-Bak Lee was elected President of Korea.
When the relevant government ministries' basic plans on climate change areconfirmed, various plans related fields are considered to be activated.
Second, judging from foreign cases of coping with climate change, alarge-scale budget seems to be injected considering the size of related
facilities. All these are part of advanced judgment, and misunderstanding
with regard to excessive design and plan is believed to be avoided later.
Third, this research selected and presented 48 research tasks on
climate change to be promoted by work in relation to NEMA's major work
concerning storm and flood damage.
The tasks to be promoted according to NEMA's work as presented inthis report should be improved through periodic changes based on the
research progress or priorities.

REFERENCES
Back, S.K., J.H., Ryu and S.B., Ryoo, 2002, Analysis of the CO2 DoublingExperiment using METRI AGCM, PART 1: The Characteristics ofRegional and Seasonal Climate Responses. J. Korean Meteor. Soc. 38(5),465-477
Bae, D.H., and J.H. Oh, 1998, A Fundamental Study on the Snowmelt
Effects for Long-Term Runoff Analysis, Journal of Korea Water Resources
Association, 31(6), 833-844
Jung, H.S., Lim, G.H., and J.H. Oh, 2001, Interpretation of the transientvariations in the time series of precipitation amounts in Seoul, Korea. PartI : Diurnal Variation. Journal of Climate 14(13), 2989-3004.
MOCT, 2001, Water Vision 2020. Document of Ministry of Construction
and Transportation, Seoul, Korea, 5-11 (in Korean).

528

New Technologies for Urban Safety of Mega Cities in AsiaHYDRAULIC EFFECTS ON VEGETATIONIMPACT BY FLOOD FLOW IN URBANSTREAMSJINHONG KIM
Department of Civil Engineering, Chung-Ang University, Korea
jinhkim@cau.ac.kr

ABSTRACT
Hydraulic effects on the vegetation impact by the flood flow andthe habitation status of the vegetation behavior by the flood flow of theaquatic plants were investigated in this paper.
The results showed that most of the aquatic plants except for Salix
gracilistyla were bent and destroyed by the high tractive force of the flood
flow, but the scrubs and the floating trashes enabled to make higher the
dynamic pressure of the flow and they destroyed even the Salix gracilistyla.
Vegetation behavior was classified into 4 stages of stable, recovered,damaged and swept away. Criteria between recovered and damaged status
were determined by the bending angle of the aquatic plants. Vegetation
whose bending angle is lower than 30~50 degree is recovered, but thevegetation whose bending angle is higher than 30~50 degree is damaged
and is not recovered. Phragmites japonica and Salix gracilistyla werestronger than the other aquatic plants against the flood flow

1. INTRODUCTION
Seasonal changes of the vegetation area in the urban streams follow therepeated cycle of the contraction and the expansion, which is originated bydestruction by flood flow and by the restoration of vegetative behavior,respectively. Transport of bed sediments during flood resulted in thedeposition of the vegetated area. During flood seasons, the vegetation may
be destroyed by the high tractive force of the flood flow, and be buried anddamaged by the transportation of the riverbed sediments. Thus, thevegetation behavior is strongly affected by the hydraulic parameters such as
flow velocity, turbulence and flow depth. Flow characteristics and theriverbed sediments affect the vegetation impacts.
Vegetation in the river is affected by flow structure, but inversely affects
flow structure. It reduces the flow conveyance, increases the flow
resistances and raises the water level. Thus, the vegetation and flow
structure has mutually reciprocal relationships.

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October 2009, Incheon, Korea

This paper presents the hydraulic effects on the vegetation impacts against
the flood flow in the urban streams. Vegetation impacts by flood flow were
investigated at Anseong-cheon, Seongbuk-cheon and Tan-cheon, and its
behavior against flood flow was analyzed.

2. VEGETATION IMPACTS BY FLOOD FLOW
Vegetation impacts by the flood flow were investigated in the urban
streams. For this purpose, Anseong-cheon, Seongbuk-cheon and Tancheon were chosen and the habitation status of the vegetation by theflood flow of the aquatic plants was investigated. Flow parameters suchas flow velocity and flow depth also measured. Measurements of the flow
features during flood times are very difficult and dangerous. Thus, the flow
velocity is usually measured at the bridge using floats. In this study, theflow velocity and the flow depth were measured using current meter andstaff within the vegetated area in case their values are not so high, but they
were measured at the bridge near vegetated area in case their values are sohigh. Flow velocity was measured using the floats, and flow depth wasmeasured using the traces of the water levels.

Figure 1: Measurement of flow velocity and flow depth

Vegetation status at Seongbuk-cheon after flood is shown in figure 2. All
the aquatic plants except for Salix gracilistyla were bent and destroyed by
the high tractive force of the flood flow. This phenomenon was also shownat Anseong-cheon and Tan-cheon. Large flood occurred at Anseong-cheon
in July 5th, 2007 and most of the aquatic plants were destroyed shown infigure 3. In case of Tan-cheon, large flood occurred in August 13th, 2008
and most of the aquatic plants were destroyed shown in figure 4. Scrubs andfloating trashes enabled to make higher the dynamic pressure of the flow,
and even the Salix gracilistyla was destroyed.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 2: Vegetation status at Seongbuk-cheon after flood

Figure 3: Vegetation status at Anseong-cheon after flood

Figure 4: Vegetation status at Tan-cheon after flood

3. VEGETATION BEHAVIOR AGAINST FLOOD FLOW
Vegetation behavior against flood flow is usually divided into four stages
such as stable, recovered, damaged and swept away shown in figure 5.

Figure 5: Four stages of vegetation behavior against flood flow

Hydraulic Effects on Vegetation Impact by Flood Flow in Urban Streams

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October 2009, Incheon, Korea

In figure 5, ‘stable’ means the vegetation is not affected against the flood
flow and thus stable. ‘Recovered’ means the vegetation is affected by thetractive force of the flood flow, but is easily recovered its features.
‘Damaged’ means the vegetation is affected seriously by the tractive forceof the flood flow and is not recovered its features even if the flood
disappeared and is finished. ‘Swept away’ means some or all the parts of thevegetated area are swept away to downstream part by the high flood flow.
Field study showed that the division criterion between ‘recovered’ and‘damaged’ of the vegetation was about 30~50 degree of the bending angleof the aquatic plants. Vegetation whose bending angle is lower than 30~50
degree is recovered, but the vegetation whose bending angle is higher than
30~50 degree is damaged and is not recovered.
This criterion may be a little different by the species of the aquatic plants.
Bending angle of Phragmites japonica and Salix gracilistyla will be larger
than that of Phragmites communis, Miscanthus sacchariflorus andPersicaria blumei. They must be further studied through more data of the
field study.
Examples of the four stages of the vegetation behavior are shown in figure 6.

(a) Stable(b) Recovered(c) Damaged(d) Swept away
Figure 6: Examples of four stages of vegetation behavior
According to the above criterion, vegetation behaviors of some aquaticplants were analyzed as below.
3.1 Vegetation behavior of Phragmites japonica

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Vegetation behavior of Phragmites japonica against flow velocity andflow depth is shown in figure 7. Here, V(m/s) is flow velocity and H(m) isflow depth.

Figure 7: Vegetation behavior of Phragmites japonica- Stable stage; V <1.4(m/s), H <1.3(m)- Recovered stage ; 0.6(m/s) < V <1.6(m/s), 1.0(m)< H <1.8(m)- Damaged stage ; 1.0(m/s) < V <1.8(m/s), 1.2(m)< H <2.0(m)- Swept away stage ; V >1.4(m/s), H >1.4(m)Phragmites japonica was inhabited in the hydraulic condition of highvelocity and low flow depth, thus inhabited in the relatively high Froudenumber. This shows that it was inhabited in the upstream reaches of thestream.
3.2 Vegetation behavior of Phragmites communis
Vegetation behavior of Phragmites communis against flow velocity
and flow depth is shown in figure 8.

Figure 8: Vegetation behavior of Phragmites communis- Stable stage; V <0.9(m/s), H <1.7(m)- Recovered stage ; 0.6(m/s) < V <0.9(m/s), 0.9(m)< H <1.9(m)- Damaged stage ; 1.0(m/s) < V <1.1(m/s), 1.0(m)< H <2.0(m)- Swept away stage ; V >1.2(m/s), H >1.1(m)Hydraulic Effects on Vegetation Impact by Flood Flow in Urban Streams533

October 2009, Incheon, Korea

Phragmites communis was inhabited in the hydraulic condition of low
velocity and high flow depth, thus inhabited in the relatively low Froudenumber compared with Phragmites japonica. This shows that it was
inhabited in the downstream reaches of the stream.
3.3 Vegetation behavior of Miscanthus sacchariflorus
Vegetation behavior of Miscanthus sacchariflorus against the flow
velocity and the flow depth is shown in figure 9.

Figure 9: Vegetation behavior of Miscanthus sacchariflorus- Stable stage; V <0.5(m/s), H <1.1(m)- Recovered stage ; 0.3(m/s) < V <0.6(m/s), 0.8(m)< H <1.3(m)- Damaged stage ; 0.4(m/s) < V <0.9(m/s), 0.9(m)< H <1.3(m)- Swept away stage ; V >0.6(m/s), H >1.0(m)3.4 Vegetation behavior of Persicaria blumei
Vegetation behavior of Persicaria blumei against the flow velocity
and the flow depth is shown in figure 10.

Figure 10: Vegetation behavior of Persicaria blumei- Stable stage; V <0.5(m/s), H <0.7(m)- Recovered stage ; 0.3(m/s) < V <0.6(m/s), 0.4(m)< H <0.8(m)- Damaged stage ; 0.3(m/s) < V <0.8(m/s), 0.7(m)< H <1.0(m)- Swept away stage ; V >0.3(m/s), H >0.9(m)534

New Technologies for Urban Safety of Mega Cities in Asia

Persicaria blumei was found in the relatively wide range of flow velocity
and flow depth, which shows that it was inhabited in the middle anddownstream reaches of the streams.
3.5 Vegetation behavior of Persicaria thunbergii
Vegetation behavior of Persicaria thunbergii against flow velocity
and flow depth is shown in figure 11.

Figure 11: Vegetation behavior of Persicaria thunbergii- Stable stage; V <0.6(m/s), H <0.7(m)- Recovered stage ; 0.3(m/s) < V <0.6(m/s), 0.5(m)< H <0.8(m)- Damaged stage ; 0.3(m/s) < V <0.7(m/s), 0.6(m)< H <1.0(m)- Swept away stage ; V >0.5(m/s), H >0.9(m)Criterion on the vegetation behavior of Persicaria blumei was not clear as
shown in figure 10, which implies that it may be effected by the flow
turbulence rather than flow velocity and flow depth. This must also be
further studied after collecting more data through the field study.

4. CONCLUSIONS
Hydraulic effects on the vegetation impact by the flood flow and thehabitation status of the vegetation behavior by the flood flow of theaquatic plants were investigated. Most of the aquatic plants except for
Salix gracilistyla were bent and destroyed by the high tractive force of theflood flow, but the scrubs and the floating trashes enabled to make higher
the dynamic pressure of the flow and they destroyed even the Salix
gracilistyla.
Vegetation behavior was classified into 4 stages of stable, recovered,damaged and swept away. Criteria between recovered and damaged status
were determined by the bending angle of the aquatic plants. Vegetation
whose bending angle is lower than 30~50 degree is recovered, but thevegetation whose bending angle is higher than 30~50 degree is damaged
and is not recovered.

Hydraulic Effects on Vegetation Impact by Flood Flow in Urban Streams

535

October 2009, Incheon, Korea

Phragmites japonica was inhabited in the hydraulic condition of highvelocity and low flow depth, thus inhabited in the relatively high Froudenumber. This shows that it was inhabited in the upstream reaches of thestream. Phragmites communis was inhabited in the hydraulic condition of
low velocity and high flow depth, thus inhabited in the relatively low
Froude number compared with Phragmites japonica. This shows that it was
inhabited in the downstream reaches of the stream. Persicaria blumei wasfound in the relatively wide range of flow velocity and flow depth, whichshows that it was inhabited in the middle and downstream reaches of thestreams. Criterion on the vegetation behavior of Persicaria blumei was notclear, which implies that it may be effected by the flow turbulence rather
than flow velocity and flow depth. This must be further studied aftercollecting so much field data.
Criterion of the vegetation behavior suggested in this study may be a little
different by the species of the aquatic plants. Bending angle of Phragmites
japonica and Salix gracilistyla will be larger than that of Phragmites
communis, Miscanthus sacchariflorus and Persicaria blumei. They mustalso be further studied after collecting more data through the field study.

ACKNOWLEDGEMENT
This work was supported by the Korea Science and Engineering Foundation(KOSEF) grant funded by the Korea government MOST (No. R01200700020
44202007).

REFERENCES
Nagata, A., Yanani S., and Nagasaka Y., 2006. Differences in up anddownstream inhabitant opinions responding to the alteration of watershedenvironment. Ecology and Civil Engineering, Vol. 9, No. 1, 73-84.
Ministry of Environment, 2007. Survey and Evaluation of Aquatic
Ecosystem Health in the Nakdong River, National Institute ofEnvironmental Research, Seoul.
National Rivers Authority, 1992. River Corridors Survey-Methods andProcedures, London.
Park, Y.-S., T.-S. Chon, I.-S. Kwak and S. Lek, 2004. Hierarchicalcommunity classification and assessment of aquatic ecosystems using
artificial neural networks. Science of the Total Environment 327, 15-122.

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EFFECT OF CLIMATE CHANGE INBANGLADESH AND DAMAGES DUE TO
TWO RECENT CYCLONESMEHEDI AHMED ANSARY
Department of Civil Engineering, BUET, Bangladesh
ansary@ce.buet.ac.bd
MD. SAIDUR RAHMAN
Research Engineer, BNUS, BUET, Bangladesh

ABSTRACT
Climate change, which is predicted by the scientist of the world, isthe most unanimous topic in the 20th century due to the assessment of someglobal climatic variables. Scientific study has found that global mean daily
temperature has increased with a rate of 0.74±0.18°c per 100 years as well
as sea level is rising 3mm per year. Due to climate change, distribution,
frequency and intensity of weather related hazards has increased, increased
precipitation is causing more flooding, and sea level rise is increasingstorm surge height.
Bangladesh is the practical example of a severely affected nation
due to tropical cyclone, flood, drought, landslides, and salinity intrusion as
well as other disasters due to climate change. High population density, highlevel of poverty, its landscape, geographical position and climate variability
has made it vulnerable to natural disaster. The climate change scenarios in
Bangladesh are analyzed through the frequently occurring natural disasters
like cyclones. On the 15th November 2007, the cyclone SIDR formed in thecentral Bay of Bengal, and quickly strengthened to reach peak sustained
winds speed of 223 km/hr. Estimated total damage and losses caused by
SIDR was $17 billion, and 3400 people were killed.
The cyclone AILA hit the coastal area of Bangladesh especially
Khulna and Satkhira districts, caused 200 death and 50,000 homeless.
Coastal polders constructed in 1960, were damaged by the tidal surge.
According to BWDB, cyclone AILA damaged 32.4 km embankmentscompletely while 178.84 km partially, where cost for maintenance andreconstruction of these embankments will be $7.75 million.
Moreover, for repairing and reconstruction of Sluice gate/regulator,
protective work, closure and other hydraulic structures will require another$4.3 million. Mud houses and shrimp production were also damaged bystorm surge.
1. INTRODUCTION

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October 2009, Incheon, Korea

On 15th November 2007, the cyclone Sidr formed in the central Bay
of Bengal, and quickly strengthened to reach peak sustained wind speed of
223 km/hr. A total of 650,000 people evacuated to emergency shelter.
About 3,363 were blamed on the storm and 1,001 people were missing and55,282 sustained physical injury. Maximum death was 1292 at Barguna.
Estimated total damage and losses caused by the cyclone was $1.7 billion.
The effects of Cyclone SIDR are equivalent to 2.8% of Bangladesh’s GDP.
The recently occurred cyclone Aila (May, 2009), which hit Khulna andSatkhira districts, caused 190 death, 50,000 homeless, 500 fishermen
missing and 3000 dysentery affected people. Coastal polders, which wereconstructed at early 1960s, had been damaged by the tidal surge. According
to BWDB, cyclone Aila damaged 32.4 km embankments completely while
178.8 km are partially damaged where cost for maintenance andreconstruction of these embankments will be $7.75 million. Moreover, for
repairing and reconstruction of Sluice gate/regulator, protective work,
closure and other hydraulic structures will require $4.3 million. According
to LGED, cyclone Aila damaged 153.86 km embankments in Satkhira
district and the estimated cost of repair/rehabilitation maintenance will be$2.41million. Mud houses and shrimp production have been damaged by thestorm surge.
2. CLIMATE CHANGE SCENARIOS
2.1 Worldwide climate change scenarios
Climate change and related global concerns are the most important
agenda in the 21th centuries because of climate variability in all over theworld. The atmospheric scientists and environmentalist have confirmed theworldwide climate change by increasing the frequencies of natural disaster.
The Intergovernmental Panel on Climate Change (IPCC) predicts that global
temperatures will rise between 1.8 Ԩ and 4.0 Ԩ by the last decade of the
21st century. The impacts of global warming on the climate, however, willvary in different regions of the world.
The IPCC also forecasts that global warming will result in sea level risesof between 0.18 and 0.79 metres, which could increase coastal flooding andsaline intrusion into aquifer and rivers across a wide belt in the south of thecountry, although most of the area is protected by polders. Rainfall ispredicted to become both higher and more erratic, and the frequency andintensity of droughts are likely to increase, especially in the drier northern
and western parts of the country.
2.2 Climate change scenarios in Bangladesh

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New Technologies for Urban Safety of Mega Cities in Asia

Bangladesh is likely to be among the countries that are the worst
affected by climate change. Tropical cyclones, storm surges, flood, drought
and river erosion are likely to become more frequent and severe in the
coming years. So, it is very important to combat against natural disaster for
our future existence in Bangladesh. Losses due to natural disaster can be
mitigated by policy making and planning. Proper assessment and action plan
is a key point to tackle disaster. UNDP has identified Bangladesh to be themost vulnerable country in the world to tropical cyclones and the sixth mostvulnerable country to floods (UNDP, 2004). Bangladesh is susceptible tofloods, tropical cyclones, storm surges, and droughts. The regions of thecountry affected by these different hazards are shown in Figure 1.

Figure 1: Vulnerability to different natural hazards in Bangladesh(Source: CEGIS, Dhaka)
Most of Bangladesh lies in the delta of three of the largest rivers in theworld – the Brahmaputra, the Ganges and the Meghna. These rivers have a
combined peak discharge in the flood season of 180,000 m3/sec. (the second
highest in the world, after the Amazon) and carry about two billion tones ofsediment each year. The topography of the country is mostly low and flat.
Two-thirds of the country is less than 5 metres above sea level and issusceptible to river and rainwater flooding and, in lower lying coastal areas,
to tidal flooding during storms (MoEF, 2009).
In the last 25 years, Bangladesh has experienced six severe floods. In
2007, two successive and damaging floods inundated the country in thesame season. During high floods, river bank erosion is common. It can
result in the loss of thousands of hectares of agricultural land and scores ofvillages, and displace many thousands of people from their homes. Flashfloods can also be a problem in the more hilly north-eastern and southeastern regions of the country.

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones539

October 2009, Incheon, Korea

One quarter of the country is inundated due to flooding. The people
living in these areas have adapted by building their houses on raised mounds
and adjusting their farming systems. In the past, people here grew lowyielding deepwater rice during the monsoon season. Now they mostly
cultivate high-yielding rice crops, often using irrigation. Once in every 4 to
5 years, however, there is a severe flood that may cover over 60% of thecountry and cause loss of life and substantial damage to infrastructure,
housing, agriculture and livelihoods. During severe floods, it is the poorestand most vulnerable who suffer most because their houses are often in more
exposed locations.
Droughts in Bangladesh are seasonal and can devastate crops, causing
hardship to poor agricultural laborers and others who cannot find work. In
these areas, unemployment leading to seasonal hunger (“Monga”) is often aproblem; especially in the months leading up to the November-December
rice harvest. If the crop totally fails because of drought, the situation forpoor people can become critical. Droughts most commonly affect thenorthwestern region, which generally has lower rainfall than the rest of thecountry.
A severe tropical cyclone hits Bangladesh, on average, every 3 years.
These storms generally form in the months just before and after the
monsoon and intensify as they move north over the warm waters of the Bayof Bengal. The wind speed of the most catastrophic cyclone in Bangladesh
ranges between 150 kph to 225 kph and can result in storm surges up to
eight metres high, resulting in extensive damage to houses and high loss oflife to humans and livestock in coastal communities.
The tropical cyclones in 1970 and 1991 are estimated to have killed
500,000 and 140,000 people, respectively. The storm surges are higher in
Bangladesh than in neighbouring countries because the Bay of Bengal
narrows towards the north, where Bangladesh is located. In recent years,
general cyclonic activity in the Bay of Bengal has become more frequent(Figure 2), causing rougher seas that can make it difficult for fishermen andsmall craft to put to sea. The climate change in Bangladesh may be
estimated from the rainfall data analysis. The climate change scenarios are
identified by tropical cyclone like the recently occurring the super cyclone‘Sidr ‘in 2007 and the cyclone’ Aila’ in 2009.

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2007

Figure 2: Tropical cyclone at different time and Path in Bangladesh(Source: CEGIS, Dhaka).
3. THE IMPACT OF THE SUPER CYCLONE SIDR IN 2007
The Super cyclone ‘Sidr’ hit at 9 p.m. on 14 November 2007 about 670 km
south of Mongla port. In Barisal coast the catastrophic of the cyclone Sidr
was observed on 15 November at 21:00 hour’s local time during ebb tide.
Wind speeds reached up to 240 km per hour affecting 15 districts with 15
others partly affected. The tract of the Super cyclone is shown in Figure 2.
More than 8.9 million people in 1,950 unions of 200 Upazilas under 30
districts were affected by Cyclone SIDR. Official reports indicated a total of
3,406 Bangladesh nationals perished during this event with 1,001 missing
and 55,282 sustained physical and psychological injuries as a result of thedisaster. Total damage is estimated to be 1.7 billion US Dollars. Total 3,319
people died in 12 affected districts, which is 97% of the total death reported
as of 21 January 2008. Highest death toll was reported in Barguna district(1,335) followed by Bagerhat (810), Patuakhali (457) and Pirojpur (400).
The MoFDM Official report indicates that 1.75 million families wereaffected in 12 districts, which is also 84% of the total affected families in 30
districts. Over 564,967 houses are fully damaged and 957,110 houses are
partially damaged. Bagerhat suffered the most in terms of fully damaged
housing (118,899 houses, 22%), followed by Barguna (95,412), Jhalakathi(69685), Pirojpur (63,896) and Patuakhali (53,291).
A comprehensive analysis undertaken by a team of Bangladesh Government
and international experts, using state of the art assessment methodologies,
estimated the total damage and losses caused by the cyclone to be BDT
115.6 billion (equivalent to US$ 1.7 billion). The effects of Cyclone SIDR
are equivalent to 2.8% of Bangladesh’s GDP. The damage and losses were
notably concentrated in the private sector, rather than in the public sector.
This has significant implications in the strategy that must be adopted forrecovery and reconstruction.
Damage and losses were concentrated on the housing sector ($0.83 billion),
productive sectors ($0.48 billion), and on public sector infrastructure ($0.25
billion). Most affected sectors were, in decreasing order, housing,
agriculture, transport, water control structures, education and industry.

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones

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October 2009, Incheon, Korea

Some photographs of the cyclone Sidr affected areas in Bangladesh are
shown in Figure 3.

(a) Erosion of soil(b) Uprooted trees(c) Fracturing of soil(d) Road damage(e) Death of animals(f) Flooding

Figure 3: Some pictures collected from Sidr affected areas in Bangladesh.
4.

THE IMPACT OF THE CYCLONE AILA IN 2009

On 25th May 2009, the cyclone Aila passed through 14 districts in the
coastal area of Bangladesh. The Aila affected 14 districts were Satkhira,
Khulna, Bagerhat, Barisal, Bhola, Pirojpur, Patuakhali, Borguna, Jhalokathi,
Chittagong, Cox’s Bazar, Laxipur, Feni, and Noakhali (Figures 4 and 5).

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Figure 4: Tropical cyclone Aila
(Map courtesy: NOAA)

Figure 5: Tropical cyclone Aila
Areas affected with surface water(After MoFDM, 2009).

Loss of life, damages to houses, livestock, crops, educational institutions,roads and embankments have been reported from 529 unions of 64 upazillasof14 districts. Official sources admitted about 190 deaths and more than
50,000 homeless people. Table 1 presents summary of damage due to 2009
cyclone Aila. Total or partial destruction of about 6,12,594 thatched houses,
3,19,930 hector harvestable paddies, large number shrimp Gher, 1,47,628
livestock and poultry. At least 7108 people were injured by the storm andabout 48,26,630 people were affected. Figures 6 to 9 show danage statistics
in different Aila affected districts and upazillas.
Mud houses and shrimp production have been damaged by storm surge. In
Nizum dwip, 20,000 people are homeless, 58,950 animals are killed and
50,000 deer have been missed. Severity of damages in different districts isshown in Figure 5. Storm surge of 3m impacted western region of
Bangladesh, submerging numerous villages. More than 4,00,000 people
were reportedly isolated by severe flooding in coastal regions of Bangladesh.
Numerous villages were either completely submerged in flood water. In
Patuakhali, a dam broke and submerged five villages. Numerous homes
were destroyed by the subsequent flooding and tens of thousands of people
were left stranded in the village.
Table 1: Summarized information on damage and loss due to the
Aila (after MoFDM, 2009).

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones

cyclone543

October 2009, Incheon, Korea

Sl. No.
1
2
3
4

Item
Quantity (No./km)
Affected District
14
Most affected district
11
Affected Upazillas
64
Affected Union
529
a. Fully affected
195
b. Partially affected334
5
Damaged Households
612584a. Fully Damaged
242882b. Partially Damaged
3697026Affected Family
8625707
Affected People
4826630
8
Crops damaged(ha)319930a. Fully damaged(ha)67840
b. Partially Damaged (ha)2520909
No. of death
190
10
Injured persons
7103
11
Missing persons
012
Dead livestock &poultry
14762813
Damaged educational Institution
2497
a. Fully damaged
357
b. Partially damaged
2769
14
Damaged roads (km)6427
a. Fully damaged (km)1319
b. Partially damaged(km)5108
15
Damaged Bridged/Culvert (No.)
157
16
Damaged embankment (km)1732.75
17People took Shelter
52955
5. THE EFFECT OF THE CYCLONE AILA ON THE INFRASTRUCTURES
Coastal polders, which are constructed at the time of 1960, have beendamaged by the tidal surge. In Satkhira districts cyclone Aila damaged 10
km embankments completely and 120 km partially, where cost for
maintenance and reconstruction of these embankments is $3.8 million.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 6: Aila affected Districts in Bangladesh (After MoFDM, 2009)

Figure 7: Total death in the Aila affected districts (After MOFDM, 2009)

Figure 8: Aila affected upazillas in Satkhira District (After MoFDM, 2009)

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones545

October 2009, Incheon, Korea

Figure 9: Aila affected upazillas in Khulna District (After MoFDM, 2009)
In Khulna district, 32.4 km were damaged completely and 178.84 km
partially $7.75million is required for maintenance and reconstruction (after
BWDB, see Table 2).
Table 2: Summary of damaged Infrastructure under BWDB, UpazillaShyamnagar, Assasuni and Koyra due to Cyclone “Aila” on dated25/05/2009 (after BWDB, 2009)
Estimated cost toType of
Actual damaged
repair/Rehabilitati
damagedQuantity
componentonkmNo.
(Taka in lac)
[1 USD=TK 69]
Embankment
211.245425.00 [$7.86 Million]
Sluice/Regulator
20
1010.00 [$1.45 Million]
Protective work
1.53
1040.00 [$1.51 Million]
Closure/etc.
24970.00 [$1.41 Million]
Total cost
8445.00 [$12.23
Million]Table 3: Summary of damaged Infrastructure under LGED, UpazillaShyamnagar and Assasuni due to Cyclone “Aila” on dated-25/05/2009
Type of damaged
component

Paved RoadHBB road
BFS road
Soling road
Culvert546

Actual damaged
Quantity

km

m

No

Estimated cost to
repair/ Rehabilitation
maintenance(TK. in lac)
[1 USD=TK 69]

63.49
54.15
18.75
18.33
--

-----

------

675.00 [$978,261]
373.00 [$540,580]
76.00 [$110,145]
67.00 [$97,101]
6.00 [$8,696]

2

New Technologies for Urban Safety of Mega Cities in Asia

Growth Centre
UP/Complex Bhaban
Cyclone Shelter
Residential Bhaban
GC & Bazar
UTDC Bhaban
Total

-----

-----

154.72

2.00

1
3
6
1
1
12.00

21.00 [$30,435]
114.00 [$1,65,217]
120.00 [$1,73,913]
18.00 [$26,087]
24.00 [$34,783]
100.00 [$1,44,928]
1594.00 [$23,10,145]

Moreover, for repairing and reconstruction of Sluice gate/regulator,
protective work, closure and other hydraulic structures require $6.96 million(after BWDB, 2009).
Cyclone Aila damaged 154.72 km embankments in Shyamnagar andAssasuni upazillas in Satkhira District of which maintenance and repairing
cost is $2.68 million. Moreover, estimated cost for repairing andmaintenance of Culvert, Bazar, Union Parishad Bhaban, Cyclone Shelter,
Growth center and Residential Bhaban is $0.5million (after LGED, See
Table 3).
6. PROBLEMS AFTER AILA
Most of the people living in the southern part of Bangladesh have seen thedevastating and destructive scenarios of cyclone SIDR. But in Cyclone Aila,
damage has been increased due to the breaching of the coastal polders. The
authority has to face difficult situation to tackle the effect of Aila.
• The polders of coastal belt in Bangladesh have been damaged due to theattack of storm surge. As a result, many villages have been inundated.
• Agricultural lands have been severely affected by the intrusion of saline
water.
• Most of the coastal areas were under water. As a result, people could notcommunicate each other due to flooding.
• Due to breaching of embankments the relief works have been hampered.
Some photographs of Embankment damage from the coastal areas in
Bangladesh after the cyclone Aila are shown in Figure 10.

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones

547

October 2009, Incheon, Korea

(a)

(c)

(b)

(d)

Figure 10: Damage of embankment due to the Cyclone Aila in Satkhira
district by the side of the Kapatakha River
7. ACTION PLAN FOR UPCOMING CLIMATE CHANGE
In 2005, the GoB has developed the National Adaptation Programme of
Action (NAPA) after extensive consultations with communities across thecountry, professional groups; and other members of civil society. The
process has been taken forward, including through the adaptation of the
Bangladesh Climate change Strategy and action plan (BCCSAP) in 2008,
which is the main basis of Bangladesh’s efforts to combat climate changeover the next ten years. The following action Plans have been taken tocombat the upcoming Climate change:• Repair and maintenance of existing flood embankments• Repair and maintenance of existing cyclone shelters• Repair and maintenance of existing coastal polders• Adaptation against floods• Adaptation against future cyclones and storm-surges• Planning, design and construction of river training works
To mitigate the problem after disaster following suggestion are provided(BCCSAP, 2008).
• Survey of the condition of coastal polders and preparation of GIS
maps with present coverage of areas protected by these polders.
• Repair, reconstruction and maintenance of existing coastal polder
based on future projected sea level rises and storm surges.
• Reconstruction and repair of polders/embankments to design heightand section
Specific recommendations due to cyclone Aila:• Quantify and periodically update the assessment of risk.
• Implement more effective mechanisms for coordination andoperation.
• Upgrade engineering design procedures and practice to place greater
emphasis on safety.
• Engage independent experts in high level reviews of all critical lifesafety structures, including cyclone and flood protection system.

548

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•

Correct the system’s deficiencies by establishing mechanisms toincorporate changing information, making the embankment
survivable if overtopped, strengthening the affected embankment.
Bangladesh is a disaster prone country. Right way construction ofembankment is required to take shelter and combat intrusion of saline water.
Coordination is mandatory for managing pre and post disaster situation.
Government has taken action plan about the constructing the embankment.
Without constructing the embankment it is not possible to implement properdisaster management.
8. CONCLUSIONS
Although Bangladesh is not responsible for the top most country of GHG
emission, some effective steps have been taken under the Kyoto Protocol.
To fight against climate change as well as tropical Cyclone, the following
considerations might be implemented. For cyclone resistant infrastructure
strengthening, foundation improvement, raising the plinths level for storm
surge, cyclone shelter construction considering facilities for women andengineered constructed house should be erected. The coastal polders, which
are fully and partially damaged, may be repaired and reconstructed byappropriate design. The minor scour on the crown and the backside of theembankment may be repaired. Design of embankment should be inspected
to reduce the risk of saline water intrusion by over passing the storm surge.
The properties of soil sample collected from embankment and borrow pit
should be tested accurately to apply soil improvement techniques. During
the time of construction, the compaction of the soil should be applied on thebasis of soil test data.
REFERENCES

BNUS (2007). Post Disaster Survey Sidr, Bangladesh Network office forurban safety, Bangladesh University of Engineering and Technology(BUET), Dhaka, Bangladesh.
BWDB (2009). Preliminary Assessment of Bangladesh Water Development
Board Infrastructure in Coastal Area of Bangladesh, Bangladesh Water
Development Board, July, 2009.
ITHACA (2009). Bangladesh-Tropical Cyclone Aila. Areas affected withsurface water as of May 27th, 2009, Information Technology for
Humanitarian Assistance, Co-operation and Action. Website:www.ithaca.polito.it/maps.php.
LGED (2009). List of Affected/Damaged Infrastructure by Recent Cyclone
Aila on 25-05-2009, Local Government and Engineering Division, July,2009.
MoEF (2005). National Adaptation Programme of Action (NAPA). Ministryof Environment and Forests, Government of the People’s Republic ofBangladesh, Dhaka, Bangladesh.
MoEF (2008). Bangladesh Climate Change strategy and Action Plan 2008.
Ministry of Environment and Forests, government of the People’s Republicof Bangladesh, Dhaka, Bangladesh.
MoFDM (2009). Tropical cyclone Aila areas Affected with Surface Water,
Ministry of Food and Disaster Management, Dhaka, Bangladesh June, 2009.

Effect of Climate Change in Bangladesh and Damages due to two recent cyclones549

October 2009, Incheon, Korea

NOAA (2009). Tropical cyclone Aila, Website: www. reliefweb. Int /rw/
fullMaps_Sa.nsf/luFullMap.
UNDP (2004). A challenge for Development, A Global Report on Reducing
Disaster Risk. Website: www. undp. org/cpr/ we_do/integrating risk.
shtml ).

550

New Technologies for Urban Safety of Mega Cities in Asia

COMPUTATIONAL ASSESSMENT OF
WINDSTORM HAZARD IN
URBAN CANYONSUNGSU LEE1, HAKSUN KIM1,GULGI CHOI1 and KWANGHYUN NAM2
School of Civil Engg., Chungbuk National University,
Seongbong-ro, Cheongju Chungbuk 361-763, Korea{joshua,haksun}@cbnu.ac.kr, gulgi-c@nate.com
2
Cubersolution co. ltd., Cheongju, Republic of Korea
khnam@ cuber.co.kr
ABSTRACTDuring windstorm period, urban area suffers from not only physicaldamages on the frame and the envelopes of structures, but fierce wind along
the urban canyon. Strong wind inside a building complex often threats
livability by generating windborne debris or heavily fluctuating flow. This
paper presents a computational study of windstorm hazard inside an urban
canyon. A large-eddy simulation (LES) is utilized to compute the unsteadyand turbulent wind flow with Smagorinsky subgrid scale model. A log-lawbased wall model was employed on all the solid surfaces including the
ground and the surface of buildings to replace the no-slip condition. The
shape of buildings was implemented on the Cartesian grid system by an
immersed boundary method. Key flow quantities for the windstorm hazard
assessment such as mean and RMS values of wind speed along the corridors
are presented. In addition, characteristics of the velocity field at someselected locations vital to safety of human beings are also reported.
1. INTRODUCTION
Recent interest in eco-friendly environment has raised needs for analysis ofwind field in urban area. In spite of numerous studies on computational
methods for wind flow around bluff bodies, the wind around building
complex has posed high difficulty in computations, most of which havebeen done by experiments. This paper presents a large eddy simulation ofwind flow around a building complex using the immersed boundary method(IBM). The complicated geometry of the building complex does not poseany computational issues since IBM (Kim et al, 2001) allows for usage ofCartesian grids with forcing terms in the governing equations.
2. FORMULATION
2.1

Governing Equations

Based on the immersed boundary method and the mass forcing forcontinuity by Kim et al. (2001), the governing equations for incompressible
fluid flow using IBM and LES are as follows;551

October 2009, Incheon, Korea

∂u j
∂x j

−q =0

2
and ∂ui + ∂ui u j = − ∂p − ∂τ ij + 1 ∂ ui + f i

∂t

∂t

∂xi

∂xi

Re ∂xi ∂x j

(1)

where xi and ui denote Cartesian coordinate and velocity component,
respectively. p represents pressure, q and f i denote mass source andmomentum forcing, respectively. τ ij is the Reynolds stress to be modeled.
Re is Reynolds number based on reference length, h and inflow velocity U .
This study employs the Smagorinsky model based on the eddy
viscosity.
(2)τ ij = −2ν SGS Sij .
SGS is the eddy viscosity for LES which has the form of

where

⎛

1 ∂u
ν SGS = (CS Δ )2 2 Sij Sij and Sij = ⎜⎜ i +2 ⎝ ∂x j∂u j ⎞⎟∂xi ⎟⎠(3)

The governing equations are discretized by a finite-volume method
which has the second-order accuracy in space. The time integration iscarried out by a fractional step method in which convection terms areintegrated by a 3rd order Runge-Kutta method and diffusion terms are by
Crank-Nicolson scheme.
uˆik − uik −1∂p k −1+ fi= (α k + β k )L uik −1 + β k L uˆik − uik −1 − γ k N uik −1 − ζ k N uik −2 − (α k + β k )
∂xi
Δt

( )

(

)

( )

( )

(4)
∂φ k
u − uˆ
=−
Δt
∂xi
k
i

k
i

(5)

where L and N denote diffusion and convection operators, respectively, andthe coefficients used in Eq. (4) are in Ref. [1].
In order to evaluate the momentum forcing f i in Eq. (4),approximation of Eq. (1) is made by using a 3rd order Runge-Kutta method
for convection term and a forward Euler method for diffusion terms;
U ik − uik −1∂p k −1= (α k + β k )L uik −1 − γ k N uik −1 − ζ k N uik −2 − (α k + β k )+ f i (5)
Δt
∂xi

( )

( )

( )

where U ik is the velocity inside the body, to be determined by theinterpolation scheme described above. Rearranging Eq. (5) leads to themomentum forcing f i which is used in Eq. (4).
2.2

552

Immersed Boundary Method

New Technologies for Urban Safety of Mega Cities in Asia

The forcing of mass and momentum depends on the relative location of
the body boundary to the Cartesian grid line. Figures 1(a) and (b) illustrates
the determination strategy for momentum forcing. When a velocity node instaggered grid line is immersed in the body, bilinear interpolations are
implemented for A in Fig. 1(a) using adjacent velocity nodes in fluid
domain or linear interpolations for B and C in Fig. 1(b). In addition, mass
imbalance due to the fictitious flow inside the body is adjusted byintroducing mass forcing, as shown in Fig. 2.

C

(a)

(b)

B

A

Figure1: Momentum Forcing

v2

q

u1

Continuity: u2 Δy + v2Δx = 0
u2v1

u2 − u1 v2 − v1
+
=q
Δx
Δy

Figure 2: Mass Forcing
3. COMPUTATIONAL RESULTS

The building complex modeled in this study was a multi-block
configuration using 9 of the Wind Engineering Research Field Laboratorybuilding (WERFL) at Texas Tech University (TTU) shown in Figure 3.
Scaled geometry was used with 1:50 to compare the present results withexperimental data (Chang & Meroney, 2003). The domain, shown in Figure
4, is 10m, 1.2m and 4m in x,y and z direction, respectively, along which
320x52x192 grid is used.

Computational Assessment of Windstorm Hazard in Urban Canyon

553

October 2009, Incheon, Korea

Figure 3: Model Configuration

Figure 4: Computational Domain
Figure 5 compares experimental sketch [2] with the computed timeaveraged velocity vectors. The recirculating flow field in the urban canyon
is well reproduced and the acceleration right outside the canyon is clearly
demonstrated.

Figure 5: Experimental (Chang & Meroney, 2003) and Computed Flow
Field inside Urban Canyon
Figure 6 shows instantaneous wind pressure and velocity on thepedestrian level, identifying hazardous region inside the urban canyon.

Figure 6: Instantaneous Wind Pressure and Velocity on Pedestrian Level

4. CONCLUDING REMARKSA practical method to simulate the wind flow around a building complex
has long been pursued in the wind engineering community. Hindered by554

New Technologies for Urban Safety of Mega Cities in Asia

computational capacity and/or numerical difficulties, wind flow around abuilding complex has been studied mostly by experiments.
This study presents a computational method for wind flow around a building
complex. LES is employed to simulate the wind flow of high Re with wall
function. Conflicts between complicated geometry and grid are resolved byusing IBM. A complex of 9 buildings is modeled and wind flow issimulated. The present method shows that wind flow around the complex
can be well predicted and it can be used on practical purposes.
ACKNOWLEDGMENTS

This work was supported by the grant from Natural Hazard Mitigation
Research Group funded by National Emergency Management Agency,
South Korea
REFERENCES[1] J. Kim, D. Kim and H. Choi (2001), An Immersed-Boundary FiniteVolume Method for Simulations of flow in Complex Geometries, J. Comp.
Phys., Vol. 171, pp. 132-150.
[2] C.H. Chang and R.N. Meroney (2003), Concentration and flow
distributions in urban street canyons: wind tunnel and computational data,
J. Wind Engrg. & Ind. Aerodyn., Vol. 91, pp.1141-1154.

Computational Assessment of Windstorm Hazard in Urban Canyon

555

PARALLEL SESSION 9DEVELOPMENT OF THE WEB-BASEDTOTAL SATETY MANAGEMENT SYSTEM
GEONHO HONG
Professor, Dept. of Architectural Engineering, Hoseo University, Korea
honggh@hoseo.edu
CHEEKYEONG KIM
Professor, Dept. of Architectural Engineering, Sunmoon University, Korea
ckkim@sunmoon.ac.kr
HEEKYU KIM
Senior Researcher, National Institute for Disaster Prevention, Korea
pietrokim@nema.go.kr

ABSTRACT
Safety of the public facilities is one of the most important factors toguarantee the citizens’ living and government responsibility. The purpose ofthis study is to design and develop the web-based total safety management
system (TSMS) for the specific control buildings and facilities in Korea.
This system supports the all safety management works from safety
inspection plan to execution and making reports of the facilities by officials
and experts in special field. To increase the efficiency and serviceability ofthe system, link plan to the existing national safety management system in
Korea was also investigated and suggested. Standards of the inspection
work flow and checklist were developed for the computerization of the safety
management works and reliability of the inspection results. This system
consists of several user types. User type is classified by their affairs;supervisor, safety management officer, expert in special field and central
government officer. This system will provide the information data to preventthe disaster, and help the establishment of safety management policy.

1. INTRODUCTION
Safety of facilities is the most primarily problem in order to guarantee astable life and properties of citizens in modern society. Change of domestic
industrial structure caused advancement and concentration of city scale, andvarious kinds of facilities increase the safety accidents and disaster on thescale and frequency.
Government make a rule to carry out safe management by the each
responsibility agency such as central and local government, disasterprevention agency and manager of the facilities. Each specialty such as fire,
structure, gas, electric and elevator carry out the safety inspection works by557

October 2009, Incheon, Korea

themselves, but it is true that integrated evaluation of the safety on thefacilities is insufficient.
Also, structural safety and maintenance of the specific facilities divided bygroup 1 and group 2 is on the line by the specific law on the safety controlof the facilities established in 1995. But the other facilities are not under thesafety check and control.
To make efficient and scientific safety control and management of thespecific control facilities assigned by the government, it is needed to
improve the classification of facilities suitable to the computational system,and to construct web-based safety management information system based onstandard safety check items and database.
The purpose of this paper is to demonstrate the web-based total safety
management system (TSMS). This is based on the "Guide of the assignmentand control on the specific control facilities" established in 2007 by the
National Emergency Management Agency to prevent the disaster of the
facilities.

2. ANALYSIS OF THE SAFETY MANAGEMENT WORKS
2.1 Overview on the safety management system in foreign countries
Safety management of the social facilities is a matter of concern in allof the countries. Safety management computational systems are usuallydeveloped and used in the field of social facilities such as bridge, tunnel andso on in foreign countries, but they do not check directly by government
offices in the case of personal and public buildings. Most countries control
the safety of personal and public buildings by the insurance system becauseof the lack of budget and usable officers. They focus to the speedy action
after disaster than disaster prevention in the fields of private and publicbuildings. But the integrated safety management information system isrequired to achieve the prevention of the man-made disaster and being
advanced country.
2.2 Facility classification in Korea
Legal structure on the safety management of the facilities divided into
2 categories. One is group 1 and group 2 facilities by the specific law on thesafety control of the facilities established in 1995. And the other is specificcontrol facilities by the basic law for the disaster prevention and safety
management. Usually, group 1 and group 2 facilities consist of large scale
facilities, and specific control facilities are middle and small scale or special
use. Specific control facilities have large number up to 2 times comparedwith group 1 or group 2 facilities. Efficient safety control of the specific558

New Technologies for Urban Safety of Mega Cities in Asia

control facilities is more important because safety consciousness of the
facility manager and budget of the safety inspection is insufficient.
2.3 Requirement analysis of the total safety management system
The system requirements for the web-based total safety management
system according to laws and field practice are described in this section.
First of all, "The Code for Assignment and Management of Specified
Management Facilities" provide that an integrated database should be built
and operated in order to share the disaster information and the result ofinspection performed periodically or occasionally can be saved in thissystem. Currently, NDMS (National Disaster Management System in
Korea) is a good system from the point of manager's view but the field
worker may feel uncomfortable because there is a big gap between thesystem and field practice.
These problems prohibit the field workers to use this system and theamount of data cannot reach to an enough one.
Therefore, total safety management system should be not separated
from the field practice and supports one stop service to field workers. In
addition, sharing of the safety management information can be done through
NDMS and the data connection between our system and NDMS is essential.
To do this, we should cooperate with the developer of NDMS to integrate
and connect these two kinds of database.
Considering the large amount of work of the officers of regional
government, the final system should save the overburdened work. Therefore
the system serves their work to select, make plan, inform, make a creditablecheck list of safety management, write reports and input to the national
disaster management system. It means that this system should be a one stop
service system for the officers of regional government.
The system requirements summarized from the interview with theofficers of regional government are as follows;a) The NDMS is a very complex system and inconvenient to the end user.
TSMS need to be simpler than NDMS and easy to use.
b) The information which is managed in NDMS is composed of only text
format database. It is very difficult to keep the informationconsistency throughout continuous inspection in this structure.
c) TSMS should reduce the amount of work of the officers in regional
government. To do this, an integrated system which serve making planof inspection and writing reports and input work to NDMS should be
developed.
d) The number of specific control facilities is too big for an officer tomanage. Therefore, TSMS is needed to manage the facilities
efficiently.

Development of the Web-based Total Safety Management System

559

October 2009, Incheon, Koreae) It is one of time-consuming works to write various kinds of reports
before and after safety inspection. In the new system, a standard
format should be designed in order to reduce the amount of work formaking reports and plans.
f) Most of the officers in regional government are not expert inarchitectural engineering. The system can make them feel convenient
in inspection work by providing the safety management guideline andcheck list.
2.4 Connection of the existing safety management system in Korea
The domestic information system which relates with the facility safety
management such as the facility management system (FMS) which is in theprocess of operating from the KISTEC (Korea Infrastructure Safety andTechnology Corporation), and National Disaster Management System(NDMS) which is operated by National Emergency Management Agency
were analyzed. However, these systems don't have much in common withthe web-based safety management system being developed in this paper.
Therefore we decided that our system have a role of giving the major
information to NDMS in order to help the decision related to the safety
management policy of government.
The main contents of the special law for facility safety management
are to manage the maintenance plan/result, facility expenses and inspection
diagnosis. The main contents of the special law are focused on 1 and 2 typefacilities. It is general the safety manager submits within 3 months in orderto report inspection and diagnosis result etc.
Ministry of Land, Transportation and Maritime operates theinformation system “Seumter”. It is made to store architectural plan andreport at the permission of the new building. This system provides the basic
design information of the building. So it could be usefully used at the timeof safety management of the facility. Use of this system started from 2008
April to be enforced, so until currently the burden of data is not many
drawing and it is in difficulties. Nevertheless, the drawings of buildings
built after 2008 April are gathered and our system can use them for thesafety management.
NDMS is a nation-wide system to prevent the natural and man-madedisasters and supports making the policies about disasters and performing
the safety management. However NDMS deals with the natural disasters
such as storms, earthquakes and man-made ones and the input format to thesystem is text-based. Therefore, it is difficult to search and make summary
even though the retrieve functions are very excellent. NDMS has powerful
functions for searching and summary and the safety management result
should be input to the system every November. So the connection between
NDMS and TSMS is significant to increase the efficiency and usefulness ofthe two systems. The data connection diagram between the existing systems
and TSMS is given in Figure 1.

560

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1: Data connection flow
3. Development of TSMS
3.1 System operation scenario
An integrated database is developed to manage efficiently the safety
management information and disaster data. In addition, TSMS is designed
to send the inspection results to NDMS.
As shown in figure 2 about operation scenario, the system manage thespecific control facilities and the database is managed for each facility. The
main users of this system are the officers of regional government. The
system development environment is composed of 3-tier, which are DB tier,Business tier, and UI tier. The facility safety management database is theDB tier, and TSMS server is the business tier which performs various kindsof works actually related to the professional work. The followings
summaries each process.

Figure 2: Operation scenario of TSMS

Development of the Web-based Total Safety Management System561

October 2009, Incheon, Koreaa) Inspection Period and Items: Facility safety management server which isoperated based the related law should inform inspection period andcontents according to the predefined period to the inspectors and facility
managers. This notification is the starting point of new inspection.
b) Site Inspection: The safety managers and each field managers visit andinspect the facilities using predefined checking list. The checking list
needs to be designed in order to make reasonable evaluation grade. So it
was made based on the deep discussion by field experts.
c) Input of Inspection Result through WEB: The inspection result is input to the
TSMS server through WEB by the safety managers and field managers. This
information is saved into the facility safety management database automatically,
and used in order to build the maintenance strategy and statistical work.
d) Analysis of Inspection Result and Decision about Follow-up Work: The
follow-up decision was made using analysis algorithm based on the input
information. This analysis algorithm is another research topic in thefollowing research project. This decision-making algorithm is one of thecores in the final system to be used practically and widely.
e) Notification of Inspection Result: Based on the analysis of site inspection
results, the inspection result is informed to the facility safety managers andfield managers, and facility owner. When some follow-up works are needed
to keep the safety of the facilities, the contents of follow-up works and due
date are informed to them.
f) Follow-up Work on Demand: When the inspection results include somefollow-up works, the result of follow-up works should be input to the systemafter doing them. The facilities which need follow-up works are separated
and managed and an UI is implemented to review the treatment.
g) Total Safety Management: It is an integrated work to do the process ofinspection period notification, site inspection, input of inspection results, safety
evaluation and follow-up works. In addition, periodical inspection result canbe managed in the format of physical report when they are required.
h) Reporting: TSMS server provides some function by which the status ofsafety management is analyzed. It also has an algorithm to provide theinformation required by NDMS.
i) Management by Special Field Expert: The special fields such as gas,
electronics, fire-resistance, and elevators have an independent server
operated by specialized experts or organizations. It may reduce the efficiencyof the system if the information should be input to TSMS because it makessome additional works to the existing work process. This means that the best
way under the current process is gather the summarized information such as
the final results and follow-up works.
j) Management of Disaster Information: The man-made disaster information
database has a role that it links the disaster information with safety
management information and analyzes the characteristics of the disasteroccurrence according the type of facility and the magnitude of the damage
and build the response strategy. To do this, the contents of the magnitude ofdamage, the response, the status of rebuild, and etc are input to the systemand the system provide various kinds of search function from several pointsof view in order to be used to analyze the characteristics of each disaster.

562

New Technologies for Urban Safety of Mega Cities in Asia

3.2 Construction of system database
The level of user's grade is divided into 4 levels according to theassigned works. The chief safety manager, the safety manager, and eachfield managers are some of them. The goal is focused to the efficiency of theofficers of the regional government because they are the end user of thesystem and they actually do the safety management work.
The starting point of the development of safety management system isthe design of safety information database. The detailed schema of the safety
information database is shown in Figure 3. The database is organizedaround the building object because all information should be gathered andmanaged for each building. The database includes information related to thefacility information, safety manager information, results of inspection work.
The database for man-made disaster is also designed around each building
same as the safety information database.
The followings are the contents of man-made disaster database.
- Building Collapse and Damage on Structural Members- Fire and Explosion- Disasters on Facilities such as Elevators- Electronics, Gas Disasters

Figure 3: Design of safety management information database

Development of the Web-based Total Safety Management System563

October 2009, Incheon, Korea

The Figure 4 shows the database schema for man-made disaster
information. The cause of disaster, the magnitude of disaster and etc are
expressed by predefined digital code, and they can be categorized andsummarized.

Figure 4: Database schema for the man-made disaster3.3 Construction of TSMS
TSMS is constructed based on the system requirements and operation
scenario. Figure 5 and 6 shows the system operation screen at the web.
Working screen is composed of 3 categories. Top of the screen represent thesystem title, and left of the screen is composed of main working menu
according to the system user group. Right of the screen is main working
space on the working menu.

564

New Technologies for Urban Safety of Mega Cities in Asia

Figure 5 represent the facility list and function of search. Mainworking screen is constructed on the tab-based menu. Figure 6 represent themaking of safety inspection check list. Check list can be hard print or mailto the parties concerned.

Figure 5: Example of TSMS display (Facility list)

Figure 6: Example of TSMS display (Check list)

Development of the Web-based Total Safety Management System

565

October 2009, Incheon, Korea

4. CONCLUSION
Safety of the public facility is one of the important responsibilities of thegovernment. Construction and application of the computational system isthe most efficient method to increase the overall efficiency of safety
management works. In this paper, analysis of the safety management works
was performed and organizes the work flow. And construction of system
database and web-based computational system for safety management
works is introduced.

REFERENCES
NIDP, 2008. Design of the On-line Safety Management System for theSpecific Control Buildings and Facilities. NIDP Research Report, Korea
NIDP, 2008. The Construction Plan of the Integrated Safety Management
System for Specific Control Buildings and Facilities. NIDP Research Report,
Korea
NIDP, 2007. Development of the Web-based Safety Management
Information System for the Facilities. NIDP Research Report, Korea
Hjork, B. C., 1994. RATAS Project – Developing an Infrastructure for
Computer-Integrated Construction, Journal of Computing in Civil
Engineering, Vol.8, No.4
Howrd, H. C., 1992. Primitive-Composite Approach for Structural Data
Modeling, Journal of Computing in Civil Engineering, Vol.6, No.1
Sause, R., 1990. A Design Process Model for Computer Integrated
Structural Engineering, Engineering with Computers, Vol. 6

566

New Technologies for Urban Safety of Mega Cities in Asia

CURRENT DEVELOPMENT OF
AN INTEGRATED STEEP-SLOPEMANAGEMENT SYSTEM FOR URBANDISASTER RISK REDUCTION IN KOREA
DUGKEUN PARK, JEONGRIM OH,
YOUNG-KARB SONG and MIN-SEOK LEE
National Institute for Disaster Prevention (NIDP),
National Emergency Management Agency (NEMA), Korea
drpark, jeongrim, sonyjin2002, sky2ms@korea.kr

ABSTRACT
Large scaled Landslide disasters in steep slopes in urban areas are
increasing due to climate change, showing uncertainties in occurrence. In
Korea most of the steep-slope disasters are induced by typhoons andtorrential rains in the Summer time, causing many casualties, property
damages, and recovery costs.
To mitigate these disasters and ensure citizens' safety, the National
Emergency Management Agency (NEMA) has established the "Steep-slope
Disaster Prevention Act" in 2008 focusing on the efficient and effective
steep-slope maintenance and management. One of the measures for steepslope disasters is to enforce early warning and evacuation practice tominimize human casualties. NEMA is trying to establish an integrated
system not only for an early warning system based on the empiricalcorrelations between rainfall characteristics and steep-slope disasteroccurrences, but also for an database for previous steep-slope disasterevents, classification schemes, and field-survey methodologies for steepslope disasters.
This paper reviews the characteristics of steep-slope disasters in
Korea and proposes steep-slope maintenance and management system ingeneral which can be adapted effectively in Korea.
1. INTRODUCTION

The risks of steep-slope related disasters are increasing due to urbanizationand increased rainfall intensity by climate change in Korea. Most of thesteep-slope related disasters are concentrated in the summer period whenmost of torrential rains and typhoons have major impacts in urban areas.
The natural disaster characteristics have been changing in Korea. The
characteristics can be simply described as, compared to the previous
decades, that the impact of natural disasters is much severer in urban areasin Korea over the last ten years and most of the killer disasters are related tothe steep-slope disasters.

567

October 2009, Incheon, Korea

It is agreeable that preventing the occurrence of steep-slope disasters
is one of the hard tasks in disaster management simply due to technicalconstraints and budget limitations. However, it may be possible to reducethe impact by steep-slope disasters when new technologies, policies,
awareness are developed, implemented, and built.
To tackle problems regarding steep-slope disasters comprehensively,
the Korean government established the "Steep-slope Disaster Prevention
Act" and has enacted since July 28, 2008 covering inspection andmaintenance procedures, monitoring requirements, early warning andevacuation practices, etc. Also, the National Institute for Disaster Prevention(NIDP) has been performing research projects on landslide early warning
systems considering rainfall characteristics in both urban and rural areas forappropriate preparedness and response to steep-slope disasters.

2. STATUS OF STEEP-SLOPE DISASTERS IN KOREA
Over the last ten years human casualties by various natural disasters in
Korea are reported every year and the number of deaths by steep-slope
related disasters is also reported continuously (NDMS, 2008; Park et al.,2008a; Park et al., 2008b; Park et al., 2007a; Park et al., 2007b). Serious
cased can be found during the typhoon events, i.e., Typhoon Rusa in 2002
and Typhoon Maemi in 2003.
According to the statistics over the past ten years from 1999 to 2008,
it is found that the number of deaths by various natural disasters is 805 and,among them, 217 deaths are due to steep-slope related disasters indicatingthat about 27% of human deaths by natural disasters is attributed to slopestability related geological disasters in Korea. Table 1 shows the number ofdeaths by natural disasters, steep-slope disasters, and their relative ratios in
Korea (NIDP, 2008).

3. STEEP-SLOPEKOREADISASTERMANAGEMENTSYSTEMIN

To mitigate steep-slope disasters several agencies and organizations are
performing related researches and routine maintenance tasks for
mountainous areas, cut-slopes along national roads, natural terrains, andslopes in urban areas.
Table 1: Death by natural and steep-slope related disasters in Korea overthe past ten years
by Slope-stability
Year
by Natural Disaster
Ratio (%)
related Disaster
Total
805
217
27.0
Average
80.5
21.7
1999
89
32
36.0
2000
49
12
24.5

568

New Technologies for Urban Safety of Mega Cities in Asia

2001
2002
2003
2004
2005
2006
2007
2008

82
270
148
14
52
62
23
16

9
79
37
3
11
22
4
8

11.0
29.3
25.0
21.4
21.2
35.5
17.4
50.0

The Korea Institute of Construction Technology and the Korea
Expressway Corporation perform stability analysis and maintenance of cut
slopes in national roads based on the specific research requests from R&D
donor agencies, and stability analysis and maintenance of cut slopes innational highways, respectively.
On the other hand, the Korea Institute of Geoscience and Mineral
Resources and the Korea Forest Research Institute carry out researches onlandslides and cut slopes based on the specific research requests from R&D
donor agencies, and landslides in mountainous areas for forest protection
and recovery, respectively. Table 2 shows main research functions ofdifferent agencies in Korea regarding slope-stability related tasks.
Table 2: Research areas in various institutions in Korea
Institution

Main Function

National Institute - Researches on geological disasters including
for Disasterlandslides and slope disasters in national level for
Prevention
disaster management aspects
Korea Institute of- Researches on landslides and cut slopes based on the
Geoscience andspecific research requests from R&D donor agencies
Mineral Resources
Korea Institute of - Stability analysis and maintenance of cut slopes inConstruction
national roads based on the specific research requests
Technology
from R&D donor agencies
Korea Forest
Research Institute- Landslides in mountainous areas for forest protection
and recovery

Korea Expressway - Stability analysis and maintenance of cut slopes in
Corporation
national highways
Most of the agencies in Korea have their own slope management
systems with a sort of early warning systems based on the measurement ofphysical properties and parameters generated by ground movement andgeotechnical monitoring. Each system has pros and cons.
However, main disadvantage of the existing early warning systems inthe view of disaster management practice for the residents arises from thatthe leading time for evacuation and preparedness is not assured. Also,
installations and operations of various monitoring equipments are

Current Development of an Integrated Steep-slope Management System for Urban Disaster Risk Reductionin Korea569

October 2009, Incheon, Korea

sometimes limited due to the cost covering vast of potentially-hazardous
slopes and areas.
Therefore, it is necessary to develop a low-cost, highly-efficient, andpractical early warning system for scattered and uncertain areas withdisaster-prone steep slopes. Especially, NIDP is trying to establish an early
warning system reflecting rainfall characteristics in local and urban areas.

4. STUDIES ON EARLY WARNING AND EVACUATION SYSTEMFOR STEEP-SLOPE DISASTERS
Based on the "Steep-slope Disaster Prevention Act" an early warning system,
data management system, and five-year research project for steep-slope
disasters have been proposed.
As shown in Figure 1, the research project is composed of three tiers
such as fundamental technology development, establishment of early
warning system, and operation of pilot systems and test beds. Main
objectives of the project are to analyze the factors affecting landslide
occurrence, to review the applicability of GIS, to propose the relationshipbetween rainfall characteristics and slope failures, to set up warning andcritical boundaries for feasible early warnings, to develop evacuation
scenarios and response system, to operate pilot system in the test beds, andproduce manuals and documents for local officials and residents.
The outcomes of the integrated steep-slope management system for
urban disaster risk reduction will include practical and tangible landslide
early warning system considering geological, landslide-occurrence, andsocio-geographical characteristics in Korea. When the project produces
successful outcomes, it is expected to be used for real-time disastermanagement in steep-slope disaster-prone areas saving people’s lives andreducing property damages.

5. CONCLUSIONS
Korea is suffering from disaster impacts by geological and meteorologicalhazards such as torrential rain, typhoon, drought, heavy snow, and steepslope failure. The disaster impacts are worsened in urban areas due to theincreased vulnerability and exposure to climate change. The seriousness ofsteep-slope disasters is especially increased in residential areas partly due tothe reckless and concentrated development.
To tackle the increased localized incidents by steep-slope failures, anintegrated steep-slope management system for urban disaster risk reduction

570

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1: Technical road map of the integrated steep-slope management
has been proposed focusing on early warning systems based on therelationship between landslide occurrence and rainfall characteristics. Six
test beds are under operation for the system refinement. Three test beds arelocated in mountainous areas and other three test beds are in hilly areas. By
2010 three additional test beds will be installed in coastal areas so thatrainfall characteristics in three different regions can be analyzed.
In the future accumulated data and technologies will be shared withinternational initiatives such as the International Consortium on Landslides
and also shared with less developed countries through technology transfer
and expert exchange.

REFERENCES
NIDP, 2008, Study on the Steep-slope Early Warning and Evacuation
System using Rainfall Data (I), the National Institute for Disaster Prevention,
the National Emergency Management Agency, Research Report (in Korean).
NDMS, 2008, The National Disaster Management System, Nation-wide
Disaster Information Compilation and Database System operated by the
National Emergency Management Agency (in Korean).
Park D, Oh J, Park J, and Chae B (2007a), Slope-stability Related Disasters
and Regulatory Countermeasures in the Republic of Korea, Proc. the Int.
Symp. on Landslide Risk Analysis and Sustainable Disaster Management(IPL 2007), January 21-24, UN Univ., Tokyo, pp. 19-23.

Current Development of an Integrated Steep-slope Management System for Urban Disaster Risk Reductionin Korea571

October 2009, Incheon, Korea

Park D, Oh J, Park J (2007b), An Application Method for Landslide Early
Warning in Wangsan Myeon Area using Rainfall Data, Proc. Korean
Geotechnical Society Spring Conf., March 23-24, Korea Univ., Seoul, pp.
1,112-1,118.
Park D, Oh J, Son Y, Park J, Lee M (2008a), Steep-slope management
system in Korea, The 2nd East Asia Landslides Symposium, Seoul, Korea,
May 22-23, pp. 7-11.
Park D, Oh J, Son Y, Lee M (2008b), Preliminary Approach for a Nationwide Regional Landslide Early Warning System in South Korea, The FirstWorld Landslide Forum, November 18-21, UN Univ., Tokyo, pp. 469-472.

572

New Technologies for Urban Safety of Mega Cities in Asia

PROPOSAL OF EFFICIENT ROAD SPACEUTILIZATION IN URBAN ARTERIAL STREETSHINJI TANAKA and MOTOMUNE KATAOKA
ICUS, IIS, The University of Tokyo, JAPANstanaka@iis.u-tokyo.ac.jp

ABSTRACTIn urban arterial streets, traffic congestion happens frequently but
available space for countermeasures is normally limited. Therefore, anefficient utilization of the limited road space is very important.
In this study, a road section which has a lot of congestion is picked up
and the cause of the congestion is identified. Then, a countermeasure whichreallocates the road space in order to increase the traffic capacity was
proposed. This is to create right-turn bay at the intersection and on-street
parking space in the middle of the link by shifting the through traffic lanes
so that right-turn vehicles and on-street parking vehicles do not block thethrough traffic flow.
The effect of the proposed countermeasure was examined by amathematical analysis and a driving simulator experiment. From themathematical analysis, it was revealed that the capacity for through traffic
would be increased by 27 %, which was enough improvement to alleviate
the congestion. Through the driving simulator analysis, it was checked
whether drivers have difficulties in driving or not by the proposed
geometrical alignment. The result showed that there are no serious risks intheir driving behavior.

1. INTRODUCTION
There are still a lot of traffic congestions in urban streets. It deteriorates theutility and the reliability of the transportation network a lot. If we haveenough budget and space, we can solve it by expanding the road orconstructing a new highway. However, available land is usually very limited
in urban area therefore it is very important to make use of the existingavailable space to extract the maximum utility.
The fundamental reason why congestion happens is the traffic demandis larger than the capacity of the road facility. In other words, when theconfiguration of the road facility does not match the actual demand, thecongestion occurs. Therefore we have to make sure whether theconfiguration of the facility is appropriate or not considering the current
traffic situation. And if it does not suit the situation, we need to modify it.
Otherwise, it produces a lot of congestion and it means a large waste of573

October 2009, Incheon, Korea

resources. In this study, a road section where a lot of congestion happens ispicked up and a countermeasure to alleviate it is proposed with someevaluation of the effect.

2. STUDY AREA
2.1 Current situation
The study area is located in the center of Kochi city in Japan, whose
population is approximately 340 thousand. The target is the main street ofthe city, running east-west through the center. It has 3 lanes for eachdirection, and tram track in the middle. In the morning and evening peak
period, 1 lane out of 3 is used for the exclusive bus lane. The street carries
more than 35,000 vehicles per day. As it is the center of the city, there are a
lot of on-street parking vehicles although it is not allowed in this section. As
a result, this street is ranked as the most seriously congested section in
Shikoku Region as shown in Figure 1.

Congestion Loss (ths hrs/yr/km)

1200
1000

target section

800
600
400
200
0

Figure 1: Traffic congestion loss by section in Shikoku, Japan
2.2 Causes of congestion
To consider the cause of this traffic congestion, let’s look at thedetector data of this section. Figure 2 shows the traffic volume data on eachlane in the evening peak counted by traffic detectors. Here, traffic volume of
3 lanes is shown, where “left” means the shoulder side lane and “right”
means the median side lane. From these figures, we can understand that thelane usage is unbalanced very much, that is, the center (2nd) lane always
carries larger traffic volume whereas the left (1st) and the right (3rd) lanes
have less traffic in both directions. It means that the road space is used
inefficiently.

574

New Technologies for Urban Safety of Mega Cities in Asia

Westbound80
70
centerveh/5min

60
50
40

left

30
20
10
0
16:00

right

16:30

17:00

17:30

18:00

18:30

Eastbound90
80
centerveh/5min

70
60
50
40
30

left

20
10

right

0
16:00

16:30

17:00

17:30

18:00

18:30

Figure 2: Traffic volume by lane
The reason why this phenomenon happens is illustrated in Figure 3.
On the left (1st) lane, there are often illegal on-street parking vehicles
because this area has a lot of business and commercial activities. On theother hand, the right (3rd) lane is a mixed use of through and right-turntraffic, therefore sometimes right-turn vehicles stop and wait for the
oncoming traffic in front of the tram track, and block following throughtraffic. As a result, through traffic vehicles tend to concentrate on the center(2nd) lane and form a queue even though the other lanes are not crowded
yet. This is the mechanism how the traffic congestion happens in thissection.
right‐turn vehicles

concentration
on‐street parking vehicles

Figure 3: Typical phenomena during congestion

Proposal of Efficient Road Space Utilization in Urban Arterial Street575

October 2009, Incheon, Korea

3. PROPOSAL OF COUNTERMEASURE
3.1 General idea
In the current situation, the road space is not fully utilized because
the left (1st) lane and the right (3rd) lane only carry much less traffic asshown in Figure 2. Therefore we should utilize this space as much as
possible. In other words, the unused road space should be reallocated so as
to suit the traffic demand.
3.2 Geometric design
Figure 4 shows the proposed geometric design of thecountermeasure. Here, 2 lanes out of 3 are assured for through traffic
although the total width of the street remains the same as the current
geometry. They are shifted to the left at the approach of the intersection sothat right-turn vehicles can stop at the right-turn bay. Also, they are shiftedto the right in the middle of the link so that an on-street parking space iscreated. In this design, the road space is efficiently used for through traffic,
right-turn and on-street parking vehicles as shown in the figure. Throughtraffic vehicles can use 2 lanes without major obstacles like right-turn
vehicles or on-street parking vehicles, so this design should have significant
improvement of the situation.
right‐turn bay

parking space

Figure 4: Geometric design of the proposed countermeasure

4. EFFECTIVENESS ANALYSIS
4.1 Mathematical analysis
To evaluate the effect of this proposal, we estimated the amount of
the improvement by a mathematical analysis first. Specifically, as thethrough traffic is congested in the current situation, the capacity
improvement of the through traffic is analyzed according to the guideline“Plan and Design of Grade Intersection”.
4.1.1 Prerequisite

576

New Technologies for Urban Safety of Mega Cities in Asia

In the current condition, there are very few through traffic vehicles
running on the left (1st) lane because there are almost always on-street
parking vehicles there. Therefore we presume that the through traffic use thecenter (2nd) and the right (3rd) lane in the current condition, and use the left
(1st) and the center (2nd) lane in the proposed condition.
4.1.2 Possible through traffic capacity on each lane
Next the possible capacity for through traffic is calculated on eachlane. Here, we employ the standard value of the saturation flow rate ofthrough traffic (SFR) as 2,000 [veh/green hr].
(a)Center (2nd) lane
The capacity for the center (2nd) lane C2 is the simplest, that is,C 2 = SFR ⋅G
G= 2000 ⋅ [veh / h]
C
C

(1)

where, C: cycle length [sec], G: effective green length [sec](b)Right (3rd) lane
For the capacity of the right (3rd) lane, we need to calculate theconversion factor of right-turn to through traffic (ERT). First, the capacity of
exclusive right-turn lane CR is,
C R = 1800 ⋅ f ⋅SG − qC 1
3600
⋅ +K⋅
[veh / h]S −q CC(2)

where, S: saturation flow rate of opposite traffic [veh/h], q: opposite traffic
flow [veh/h], f: probability of right-turn gap during opposite traffic q (f=0
under q>1,000), K: number of right-turn vehicles which can stop inside theintersection [veh/cycle] (approx. 3 [veh/cycle]).
The conversion factor of right-turn to through traffic (ERT) is
calculated by dividing (1) by (2), that is,G
1 .1
C
E RT ==SG − qCK
SG − qC 2 K
f⋅1800 f ⋅+ 3600+C (S − q)C
G ( S − q) G
2000

(3)

Then, the correction factor of the saturation flow rate for the mixed
lane of right-turn and through traffic αRT is,
α RT =

100(100 − R ) + E RT ⋅ R(4)where, R: right-turn vehicles ratio
Therefore the capacity for the right (3rd) lane C3 is,C 3 = SFR ⋅GG⋅ α RT = 2000 ⋅ ⋅ α RT [veh / h]CC

Proposal of Efficient Road Space Utilization in Urban Arterial Street

(5)

577

October 2009, Incheon, Korea(c)

Left (1st) lane
Similarly for the capacity of the left (1st) lane, we need to calculate
the conversion factor of left-turn to through traffic (ELT). First, the capacityof exclusive left-turn lane CL is,
C L = 1800 ⋅(1 − f P )G P − (G − G P )[veh / h]C(6)where, GP: pedestrian green length [sec], fP: reduction ratio of left-turnthroughput by pedestrians (0.15 - 0.50)
The conversion factor of left-turn to through traffic (ELT) is calculatedby dividing (1) by (6), that is,G
1.1G
C
E LT ==
1800{(1 − f P )G P + (G − G P )} (1 − f P )G P + (G − G P )
C
2000

(7)

Then, the correction factor of the saturation flow rate for the mixed
lane of left-turn and through traffic αLT is,
α RT =

100(100 − L) + E LT ⋅ R(8)where, L: left-turn vehicles ratio
Therefore the capacity for the left (1st) lane C1 is,C1 = SFR ⋅GG⋅ α LT = 2000 ⋅ ⋅ α LT [veh / h]
C
C

(9)

4.1.3 Estimation of the effectUsing the possible traffic capacity on each lane derived as above, theeffect of the proposed design is estimated. Table 1 shows the values used inthis estimation.
Table 1: Parameter values for the estimation
Parameter
Value
2,000 [veh/green hr]
SFR Saturation flow rate of through traffic
Right-turn
vehicleratio
10 [%]
R
Left-turn vehicle ratio
10 [%]
L
Cycle length
120 [sec]
C
Effective green length
60 [sec]
G
Pedestrian green length
55 [sec]
GP
Probability of right-turn gap
0fReduction ratio of left-turn by pedestrian
0.5
fP
From Eq. (1),578

New Technologies for Urban Safety of Mega Cities in Asia

C 2 = 2000 ⋅60= 1000 [veh / h]
120

(10)

From Eq. (3) and (4),E RT =

1.1
= 11
2×3
60

α RT =

100= 0.5(100 − 10) + 11 ⋅ 10

(12)

60
⋅ 0.5 = 500 [veh / h]
120

(13)

(11)

Then, from Eq. (5),C 3 = 2000 ⋅From Eq. (7) and (8),1.1 × 60
= 2.03(1 − 0.5) ⋅ 55 + (60 − 55)
100= 0.91
α RT =(100 − 10) + 2.03 ⋅10
E LT =(14)(15)

Then, from Eq. (9),C1 = 2000 ⋅60⋅ 0.91 = 907 [veh / h]
120

(16)

Finally, the through traffic capacity of the current situation and the
proposed one are,
Current: C2+C3=1,500 [veh/h)
(17)
(18)
Proposed: C1+C2=1,907 [veh/h]
From this result, the through traffic capacity is increased by 27%, thatis enough value compared with the excess demand of the normal traffic
congestion. Therefore we can expect to solve the congestion by this
proposed geometric design.
4.2 Driving behavior analysis
Even though the proposed design has a significant advantage incongestion alleviation, it is difficult to apply it if we cannot confirm thedriving safety. Especially, as the proposed design includes a lateral shift ofthe lanes in the middle of the link, it is essential to examine whether thisshift makes a negative impact on the safety or not. To evaluate this, we
conducted a driving simulator experiment.
4.2.1 Settings
Figure 5 shows the appearance of the driving simulator used in thisanalysis. The features of this driving simulator are 6-axis motion platform,
turn table, 360 degrees screen and so on. It can record various indices ofdriving behavior, such as speed, acceleration / deceleration, steering angle
etc. And it can also record driver’s behavior by video cameras.

Proposal of Efficient Road Space Utilization in Urban Arterial Street579

October 2009, Incheon, Korea

Figure 5: Appearance of the driving simulator
2 scenarios were prepared for the experiment, which are the current
geometric design and the proposed one. Each testee drove on the course 4times per scenario, following some practice runs. The testees wereinterviewed after their driving about their subjective evaluation. Table 2
shows the attributes of the testees.
Table 2: Attributes of the testees [num, (%)]
25 or less 26 - 64
65 or moreAge
5(38.5)7(53.8)1(7.7)
Male
FemaleSex11(84.6)2(15.4)
~
1
year
~
5
year
~
10
year
More
Drivinghistory0(0.0) 3(23.1)
2(15.4) 8(61.5)
4 or more 1 - 3 1 - 3 Less
Driving/week/week/monthfrequency
1(7.7) 3(23.1)
2(15.4) 7(53.8)
Yes
No
Know thelocation?
2(15.4)11(84.6)
4.2.2 Results
4 checkpoints were examined from the recorded data, that is,whether brake was used or not at the lateral shift, how much the maximum
value of lateral acceleration was, whether the value of lateral acceleration
was different from the existing section, and whether sharp steering
maneuver was found or not. The results are shown in Table 3.
Table 3: Experiment result [num, (%)]
Yes
Use of brakeNo
Max lateral acceleration [G]
0.2 ~ 0.35
0.15 ~ 0.2

580

1(7.7)
12(92.3)
1(7.7)
2(15.4)

New Technologies for Urban Safety of Mega Cities in Asia

Comparison with the existing section

Sharp steering maneuver~ 0.15
More
Same
Less
No

10(76.9)2(15.4)5(38.5)6(46.2)13(100.0)

As for the brake use, only 1 testee used it. However the deceleration
rate was not so hard (0.12 [G]) and the testee answered that he used a brake
not because of the lateral shift but the difference of the driving feeling fromthe actual vehicle.
Previous studies indicate that the lateral acceleration value more than
0.15 [G] may influence some patients on an ambulance and the value of0.22 [G] is used to detect potential risks in expressway. The maximum valueof lateral acceleration in this experiment showed less than 0.15 [G] in mostof the cases, but more than 0.2 [G] in 1 case. This testee also answered that
it was difficult to maneuver the steering of the simulator but not difficult
about the alignment, so it seems a matter of the experiment equipment.
As for the comparison of the lateral acceleration with the existing
section, larger acceleration was observed in 2 cases. However, their absolutevalues were not dangerous level in either case.
Finally, there were no sharp steering maneuvers found in all 13
testees’ runs.

5. CONCLUSIONSThis study insisted on the importance to utilize road space efficiently inurban area to alleviate traffic congestion. And taking an example of anarterial street in Kochi city, road space reallocation to alleviate congestion
was proposed. This proposal does not require extra land, so it is relatively
feasible measure than a large scale renovation in urban area. The effect ofthe proposal was evaluated by a mathematical analysis and a driving
behavior analysis from a viewpoint of efficiency and safety, respectively.
The result showed that enough capacity improvement was expected forthrough traffic to solve the congestion and no serious behaviors leading torisks were found in the experiment. We believe this kind of fine and carefulmanagement of infrastructure is very important to keep the traffic network
working and to establish sustainable urban environment.

REFERENCES
Kamimura, A., Kataoka, M., Tanaka, S., Kumagai, Y., Kuwahara, M., andNasu, S., 2007. Proposal of new road manner of operation and untie a traffic
jam project, Proceedings of the 35th Conference of Infrastructure Planning,
Spring Meeting, JSCE, CD-ROM (in Japanese).

Proposal of Efficient Road Space Utilization in Urban Arterial Street581

October 2009, Incheon, Korea

Kataoka, M., Tanaka, S., Kumagai, Y., and Kuwahara, M., 2008. Proposalof ease traffic jam measures by dynamic lane, Proceedings of the 37th
Conference of Infrastructure Planning, Spring Meeting, JSCE, CD-ROM (inJapanese).
Kataoka, M., Kumagai, Y., Nakagawa, T., Yamaguchi, D., Tanaka, S., Suda,
Y., and Kuwahara, M., 2009. Safety verifications of countermeasures toalleviate traffic congestion on Route 32 using driving simulator,
Proceedings of the 40th Conference of Infrastructure Planning, Autumn
Meeting, JSCE, CD-ROM (in Japanese).

582

New Technologies for Urban Safety of Mega Cities in Asia

STUDY ON THE COASTAL DISASTER
PREVENTION SYSTEM USINGEVACUATION MODELSUNGJIN HONG
Senior Research, National Institute for Disaster Prevention, NEMA, Korea
hongsj@nema.go.kr
TAEKJO KOH
National Institute for Disaster Prevention, NEMA, Korea
HYOUNGSEONG PARKNational Institute for Disaster Prevention, NEMA, Korea

ABSTRACTThe objective of this research is to investigate the evacuation systemof coastal inundation area and to support a decision by effective selection of
shelter and routes by using evacuation model. In this report, numericalmodels for evacuation such as network model, potential model and multiagent system model are reported. And its applicability of them is also
discussed. The result shows that the potential model has advantage forrepresenting individual behaviors with particles. The disaster management
for reduction of coastal inundation damages is tested in numerical model.
The numerical experiments are carried out in the Woryeong-dong, Masan
for analyzing evacuation routes and shelter. Furthermore, a questionnaire
is designed to determine escape route selection, parameters and initialconditions of the evacuations. The questionnaire survey is performed foranalyzing the resident's knowledge about coastal inundation.

1. INTRODUCTION
Coastal disasters have become one of the most important issues in every
coastal country. In Korea, coastal related disasters such as storm surge, sealevel rise and extreme weather have placed many coastal regions in dangerof being exposed or damaged during subsequent storms and gradualshoreline retreat. A storm surge is an onshore gush of water associated witha low pressure weather system, typically in typhoon season. However, it isvery difficult to predict storm surge height, tsunami height and inundation
due to the irregularity of the course and intensity of a typhoon, tsunami andso on. Therefore, it is necessary that adequate evacuation system is preparedin accordance with formalities.
A well-designed system for evacuations warning issues is essentiallynecessary to reduce human loss and damages. A lack of tools of an583

October 2009, Incheon, Korea

evacuation system has such problem as long time simulation time. The
objective of the present study is to develop the effective evacuation system
by survey and numerical experiments. Detailed contents are as follows: (i)Firstly, questionnaire is designed to be distributed at the time of the drill,which provided us information to determine route selection, parameters andinitial conditions of the evacuations. Various parameters like as regional
knowledge, altitude, road information, road signs, following process, andfunctions on the route to be major factors in the route selection aredetermined to analyze the evacuation system. Consequently, moving speed
and earlier starting of evacuation are important parameters to minimize total
morality and missing rate. Using selected parameters, field survey is carriedout to clarify various factors that influence selection of evacuation routes formaking a synthetic judgment model. (ii) Secondly, numerical experiments
using the potential model are applied to analyzing the evacuation situationin study area. It is possible that the potential model shown in Figure 1
presents individual behavior of evacuees as particles. Recently, various
studies using the potential model have been carried out in the field of coastal
prevention.

Figure 1: Method of risk potential

2. COUNTERMEASURES FOR DISASTER PREVENTION
It is necessary that establishment of evacuation building is established for
preparing emergency situation in coastal inundation area as shown Figures 2
and 3. In Korea, however, building owner is reluctant to be selected forevacuation building because of the lack of public relations and management
problems. Consequently, it is try to find the solutions to the problems thatare costs of management and damage according to selection for evacuationbuilding. It is required that solid buildings are positively appointed

584

New Technologies for Urban Safety of Mega Cities in Asiaevacuation shelters through its many incentive programs. Also, it isdesirable that evacuation building is selected with consideration of acollision between building and ship, flotage by storm surge or tsunami andso on.

Figure 2: Selection method of evacuation region within the limits

Figure 3: Concepts of evacuation building
In the choice of evacuation routes, it is important that routes near to seek
rather than the short distance are selected. If evacuation route goes acrossthrough a residential street, tourists and foreigner cannot look for shelter soreadily. Though evacuation building is completely not guarantee the safetyof evacuees, it is applied to safety against coastal disaster for the nonce.
Therefore, it is necessary that a standard of the utilization and management
for evacuation building is established in process of previous structured andunstructured prevention measures.
Though structural surge prevention measures such as construction of
breakwater, installation of shelter, and maintenance of tidal observation
instrument are progressing, it is not enough for perfect prevention of coastal
disaster for surge. Because of occurring of damages which are different
from past are expected due to possibility of unexpected big surge, change ofland utilization on the coast area, development of tourist and ocean leisureindustry.
Even though prevent of property loss is important, more important factor isprotection of people's life. To avoid huge casualty, disaster warning andevacuation advisory, and fast forwarding to local residents is needed inadequate time. But this process is hardly executed. Also, if residents don't
want to evacuate after they listen evacuation advisory also could be a
problem. Possible reasons of such behavior could be uncleanness of

Study on the Coastal Disaster Prevention System using Evacuation Model585

October 2009, Incheon, Korea

advisory, unable to judgment because of no specific standard, no research
about natural phenomena and dike which are factors of disaster. Also,
residents don't know how to be acting, cannot recognize the danger of them.
In particular, the recent characteristics of the problem are about theevacuating of elderly, infants. To minimize the damage in the expected
coastal disaster area, the evacuation system for residents, installation of
shelter in safe area, set routes for rapid evacuation, set coastal inundation
area are need to be established for evacuation system for quick and safe
evacuation of residents.
In this research, analysis of resident' cognition on coastal inundation fromsurvey of a study area is performed. With this result, disaster prevention
measures for safe evacuation will be researched. Evacuation model
represents the delivery type of disaster information, social phenomena(about evacuation system), and physical phenomena (tsunami arrived in the
coastal area). Also, it is possible that the model calculates the feasibility ofpositioning shelter, the effective evacuation route and required time by thenumerical simulation based on actual tsunami damage data.

3. APPLICATION OF EVACUATION MODEL
It is difficult that real training for evacuation is carried out in the field of
disaster prevention against earthquake, fire, flood, inundation and so on.
That is why numerical experiment is applied for analyzing the presumptionof damage scale and assessment of prevention plan. In previous studies,
small-scale numerical experiments were carried out. However, recently
large-scale numerical models are developed for simulating the behavior ofhuman. Essentially, it is prepared that evacuation system against storm
surge, tsunami in coastal area is established for risk reduction of human loss.
In interest of prevention, proper evacuation routes must be selected throughanalyzing the behavior of human.
In this chapter, we explain the evacuation numerical models like as networkmodel, potential model and multi-agent system model and its applicability isalso discussed.
3.1 Evacuation model
Evacuation models are applied to investigate the disaster prevention
measures against earthquake, tsunami, storm surge, flood and so on. They
are divided by (i) application region, (ii) constitution of evacuees and (iii)
determination method of their behavior.
Because it is possible that the potential model represents individual
behavior of evacuee as particles, various studies have been carried out
recently on the potential model in the field of coastal prevention.

586

New Technologies for Urban Safety of Mega Cities in Asia

As shown Figure 4, the potential model has the advantage ofrepresenting behaviors of individuals by particles. The potential model is akind of physical model that represents the behavior according as assumptionof specified law for individuals in a group. It is possible that the potential
model establishes a proper potential energy about geographical features of
evacuation routes, personal features of evacuation and disaster situations invarious evacuation simulations. Also, the potential model can represent thebottleneck situation of evacuees by setup of numerical parameters.

Figure 4: Explanation of the potential model and network model
3.2 Theory of potential model
The potential model is consisted of grid system by dx × dy. Each grid
represents risk potential for evacuation situation in coastal inundation area.
The distribution of potential is defined as follows: N ( X , t )    Nj ( X , t )    Nk ( X , t )    Nl (t ) Nl ( X , t )
j

k

(1)

l

 N ( X , t ) : distribution of potential applied to evacuee N  Nj ( X , t ) : distribution of common potential applied to every evacueesj  Nk ( X , t ) : distribution of potential for personal features applied to evacuee Nk Nl (t ) Nl ( X , t ) : distribution of potential for disaster cause applied to evacuee NlIn order to reach the destination, each evacuee selects the shortest
course which represents the lowest potential from between numerical grids.
Therefore, the potential model represents simply a disaster situation like aspersonal feature, topographical conditions and so on. Furthermore, it ispossible to analyze the characteristic of individual behavior in a group.

Study on the Coastal Disaster Prevention System using Evacuation Model587

October 2009, Incheon, Korea

4. RESULTS AND ANALYSISThe numerical experiments are carried out for analyzing the characteristics
of evacuation routes and shelter in Woryeong-dong, Masan. According to
the report (Masan, 2004), typhoon 'MAEMI' caused extensive damage inthis area. In detail, about 85 people died (with 25 others reported missing) in
the storm and 250,000 people were forced to evacuate. The prevention
measures of disaster are required for evacuation system because this area is
not only strengthened an intensity of typhoon but also expanded a risk ofinundation by storm surge.
Four areas are assigned the shelters for coastal inundation as follows: HaeAn elementary school, Seo-Masan middle school, the office of Woryeongdong and Shin-Masan hospital. In numerical experiments, two area (Hae-An
elementary school and Seo-Masan middle school) are selected from among
them for numerical simulation following as Figure 5. Furthermore it isassumed that the wave is propagated from the east to the west.
Figure 6 shows evacuation situation at each time series. Evacuee calculates
the shortest route to the shelter and they make a detour when they meetobstacles. Result shows that 90% of residents evacuate in 25 minutes. But
preparing time for evacuation is almost takes 30 minutes, so actual
evacuation time takes about 55 minutes. The result is quite different from
'Emergency 30 minutes plan' of government. It means because of preparing
time to evacuate takes a lot of time, quick evacuation order can't guarantee
the safety of resident. To solve this problem, continuous education about
area of coastal inundation, location of shelter, evacuation route is required.
To calculate the actual required time and find the ideal location of shelter,
verification and modification of the plan are required by real evacuation
simulator or numerical simulation. And more public relations of the plansuch as a PR brochure or a guidebook is needed.

(a) Topography for study area(b) Wave direction, locations of shelter
and evacuees
Figure 5: Information for numerical simulations in Woryeong-dong, Masan

588

New Technologies for Urban Safety of Mega Cities in Asia

(a) After 1 minute(b) After 5 minutes(c) After 15 minutes(d) After 30 minutes
Figure 6: Locations of evacuees at each time by numerical experiments

5. CONCLUSIONS
Quick evacuation is important to reduce casualties by inundation. Quick andexact transmissions of surge monitoring and adequate evacuation system are
required. For these we developed system to support decision making to findeffect escape routes and the results obtained from this research are following
as: (i) Shelter building is need to be install in predicted coastal disaster area;(ii) Easy accessibility is more important than the shortest route to theshelter; (iii) Active promotion and education plan are need to improve
cognition about inundation through a survey; and (iv) Provide a direction to
improve the 'Plan for evacuation in 30 minutes' and the 'Guidelines forcoastal disaster map'. Evacuation model need to improve for decision
support system or disaster management system as follows: (i) Residents
consider only short route and risk potential when they evacuate. accordingly,
they used to use narrow route so that congestion of evacuation route isoccur; (ii) Technique to install a fence is required to prevent congestion ofevacuation route; and (iii) Numerical model which has not only evacuation
simulation but also coastal inundation is required.

Study on the Coastal Disaster Prevention System using Evacuation Model589

October 2009, Incheon, Korea

REFERENCES
Fararo, T. J., 1981. Based Network and Social Structure Theorems, Social
Networks, 3, 137-159.
Ichimura, T., M. Hori, K. Terada, and Yamakawa T., 2002. On intergrated
earthquake simulator prototype : Combination of numerical simulation andgeographical information, J. Strcu. Mech. Earthquake Eng., JSCE.
Imamura, F., 1996. Review of Tsunami Simulation with a Finite Difference
Method, Long-Wave Run-up Models, World Scientific, River Edge, NJ, 4387.
Koshimura, S., H. O. Mofjeld and Moore A., 2002. Modeling the 1100bp
poletsunami in Puget Sound, Washington, Geophysical Research Letters,
29(20), 91-94.
Masan, 2004. Analysis of Typhoon 'MAEMI' and Coastal Disaster
Prevention, Research Report, KSCE, 241p.
Okazaki, S., 1979. A Study of Simulation Model for Pedestrian Movement
on Architectural Space, Part 1 : Pedestrian Movement by the Application ofMagnetic Models, Transaction of Architectural Institute of Japan, 111p.
Okazaki, S., 1979. A Study of Simulation Model for Pedestrian Movement
on Architectural Space, Part 3 : Along the Shortest Path, Taking Fire,
congestion and Unrecognized Space into Account, Transaction ofArchitectural Institute of Japan, 137p.
Okazaki, S. and Matsushita, S., 1993. A Study of Simulation Model for
Pedestrian Movement with Evacuation and Queuing, Proceeding of theInternational Conference on Engineering for Crowd Safety, 271-280.
Yang, F., T. Ichimura and Hori M., 2002. Earthquake simulation in virtual
metropolis using strong motion simulator and geographic information
system, Journal of Applied Mechanics, JSCE, 5, 527-534.

590

New Technologies for Urban Safety of Mega Cities in Asia

INTRODUCTION OF DISASTERIMAGINATION WORKSHOPINTO RISK-MANAGEMENT TRAININGFOR NURSERY SCHOOL LEADERS
1

1

MARIKO ABE, 2KIMIRO MEGURO, and 3MARI YOKOYA

Department of Civil Engineering, The University of Tokyo, Japan
abe@risk-mg.iis.u-tokyo.ac.jp
2
International Center for Urban Safety Engineering,
Institute of Industrial Science, The University of Tokyo, Japan
3
Institute of Industrial Science, The University of Tokyo, Japan

ABSTRACTJapan is expected to face several big earthquakes in the near future.
There are two important points for nursery school people to protect smallchildren from such big earthquakes. First, each member of a nursery school
should improve the disaster imagination. Second, members should share
their image and experiences with each other. Therefore, we designed andconducted a Disaster Imagination Work Shop (DI-WS) at a nursery school(Abe and Meguro, 2005).
In this paper, to expand the field of DI-WS application to other risks
and let it popular, we attempted to introduce DI-WS into general risk
management training for nursery school leaders. However, since Japan is
an earthquake disaster prone country and leaders are strongly interested inearthquake disaster, as the first step of the approach, we picked up
earthquake disaster as an example from all risks that we should consider.
We have designed a training program composed of two workshops. The firsthalf is Problem Sharing Work Shop (PS-WS) concerning all risk issues, andthe latter half is DI-WS based on PS-WS. Then, we carried out this programand examined the possibility of expanding DI-WS approach. Finally, basedon the result, we listed up problems for expanding this approach andproposed a DI-WS support system.

1. INTRODUCTION
Japan is expected to face several big earthquakes in the near future. There
are two important points for nursery school people to protect small children
from such big earthquakes. First, each member of nursery school should
improve the disaster imagination. Second, members should share theirimages and experiences with each other.

591

October 2009, Incheon, Korea

Therefore, we have designed and conducted a Disaster Imagination Work
Shop (DI-WS) at a nursery school (Abe and Meguro, 2005). In this WS, theparticipants first decide the conditions such as season, day of the week,
occurrence time, weather, and seismic intensity, etc. Then, they start
imaging the situation around them as time goes since the hazard attack, andmake a story in which they are central figure (Figure 1). In addition, they
write down the questions and problems on the memo pads. After writing,they line up their story seats on the table and read each story, comparing
along time passage. Sometimes the images of each member are different.
Through this practice, WS members can imagine their possible disastersituation and share their images, questions and problems.
To expand the field of DI-WS application to other risks and let it popular,
we attempted to introduce DI-WS into general risk management training fornursery school leaders. However, since Japan is an earthquake disasterprone country and leaders are strongly interested in earthquake disaster, as
the first step of the approach, we picked up earthquake disaster as an
example from all risks that we should consider. We have designed a training
program composed of two workshops. The first half is Problem Sharing
Work Shop (PS-WS) concerning all risk issues, and the latter half is DI-WS
based on PS-WS. Then, we carried out this program and examined thepossibility of expanding DI-WS approach. Finally, based on the result, welisted up problems for expanding this approach and proposed a DI-WS
support system.

Fix the typeof disasterWrite in your own
situation when thedisaster occurs

Earthquake

6-odd

2009.08.19

CONDITIONS
winter

WEATHERSEASONTIME

fair

a.m.10:30
OONAMI. Usuru
Nurseryworker
teacherparentEarthquake Occur
震度６強

10 sec.

1 min.

your situation

Gather andsurroundWe’re playing babies
with babies.
（Teachers: 2 BABIES
0-1 years oldbabies: 6）

大人

POSI
WRITER -TION

Set the conditionsDATE

SEISMICINTENSITY:

Imagine your situation
after disaster, and makea story of yourself

Call nur
by mobiphone

ADULTS
29

Figure 1: Disaster imagination tool592

New Technologies for Urban Safety of Mega Cities in Asia

2. DESIGN OF RISK MANAGEMENT TRAININGFOR NURSERY SCHOOL LEADERS
In this chapter, we will introduce the situation of the risk-management ofnursery schools today in Japan and the risk management training for nurseryschool leaders, and explain about the flow of design of the training program.
2.1 Risk management training for nursery school leaders
National guideline for nursery school, which was revised in 2008,
clearly describes that a nursery school director should take responsibility inmatters of safety of children at his/her nursery school. Recently, risk
management training for nursery school leaders, such as director and chiefs
who help director, are being held. These trainings are executed by the social
welfare corporation or the municipality. Medical Doctors, lawyers, risk
consultants, NPOs and others related to children’s safety give lectures in the
training. The lecturer is decided by direct nomination or competition, etc.
Training takes several hours to several days. However, support system for
feedback for participants after going back to their nursery school, or the
succession of the previous year's training data for next year is not enoughyet.
2.2 Design of the training program
In order to introduce DI-WS into the training for the directors and thechiefs who are leaders of nursery schools, we designed training programthat include DI-WS, and applied it for the competition of the 2009 riskmanagement training sponsored by the Tokyo Municipality Training
Institute. The competition was nominated tender, and Ms. Yokoya, one of
the authors, her NPO was also nominated. The number of participants
expected was about 60, and the time of the training planned was 6 hours.
In this study, in order to expand the field of DI-WS application toother risks and let it popular, we tried to introduce DI-WS into general riskmanagement training for nursery school leaders. However, since Japan is anearthquake disaster prone country and leaders are strongly interested inearthquake disaster, as the first step of the approach, we picked up
earthquake disaster as an example from all risks that we should consider.
We have designed a training program composed of two workshops. The firsthalf is Problem Sharing Work Shop (PS-WS) concerning all risk issues, andthe latter half is DI-WS based on PS-WS.
We divided approximately 60 participants into 9 groups composed of
6-7 members. Emcee, facilitation and recording were done by 6 staffs (2NPO members and 4 postgraduate students). To share information smoothly
among participants, basic information of all nursery schools must be
understood first. Therefore, we prepared some basic information seats to fillin the number of staffs and children, construction year of school buildings,
indoor map, outdoor map, playground map, and map around the nurseryschool ( route to the park, feature around and so on).

Introduction of Disaster Imagination Workshop into Risk-Management Training for Nursery School Leaders 593

October 2009, Incheon, Korea

In PS-WS, each participant writes past accidents, shivering events,
uneasiness, questions and problems freely on the cards. Then, they arrange
the cards on a large paper, discussing in each group. Finally, presenter of
each group explains about their discussion result, sharing information as awhole. We designed the cards in order to arrange the data easily after the
training.
In DI-WS, we set 5 conditions - weather, seismic intensity, season,
earthquake occurrence time and a day of the week, which may change thesituation and the correspondence after the earthquake. The disaster
imagination can be widely shared in a limited time by imaging different
conditions in each group and sharing them with all participants. However,extreme different conditions may cause confusion when they compare theirsituations. So, in this program, we set a common condition for weather andseismic intensity as "fine and JMA intensity of 6+" among all groups, anddifferent conditions for season, earthquake occurrence time and a day of the
week.

3. RESULTS OF THE PROGRAM
The program we designed received high valuation and was adopted by the
Tokyo Municipality Training Institute, and we carried out the program in
August, 2009 (Figure 2, 3). This chapter describes the result of this training
program.

Figure 2: participants and staffs

Figure 3: PS-WS (left) and DI-WS (right)

594

New Technologies for Urban Safety of Mega Cities in Asia

PS-WS (Problem Sharing Work Shop)
When a big earthquake occurs, can nursery school teachers really moveand protect the children?

DI-WS (Disaster Imagination Work Shop)
Is my house OK? Do fires occur?
How about the neighborhood of my house?
I should go to nursery school,
but are families all right?
Can I bring my mobile phone?
Can I contact with my husband?
Usually it takes 7 minutes by walkto the nursery school, but can I pass the road?
Is the building of the nursery school all right?
Isn't there any child who has been injured?
I wasn’t worried about the toilet and the meal.

30min
later
5min
later
20min
later
1hour
later
2hourslater
othersFigure 4: Example of problems going detail
Table 1 Setting condition and content of the presentation of each group
group

seasonday of theweekoccuringtime

1

summerweekday

8:00

Situation whenthe earthquake
occursgoing to work

Contents(Extracts)･How to contact with the parents?

2summerweekday

10:00

Taking care ofchildren･The tasks changes according to thestandpoint. The director and the chief
should think about the whole matters, andthe other teachers should take care ofchildren's mental aspect.

3

winterweekday

10:00

Taking care ofchildren･Can we serve warm meals?
･Because it is cold, small children cannot
refuge in clothes alone .
･Tableware may be scattered･I’m worried about the heat under hot
weather.
･Can I understand the whole situation at
once? Some of the staffs are taking a rest.

4

summerweekday

12:00

Eating lunch/brushing teeth/children taking
a nap

5

summerweekday

14:00

children taking
a nap, adults
taking a break6

summerweekday

16:00

7

winterweekday

16:00

8

summerweekday

18:00

shifts to theovertimechildcare･Correspondence is difficult because of
the time zone shifting to night.
･How can we respond by few people?

16:00

Few people aretaking care ofchildren /at
home\･How can we respond by few people?
･If parents' offices are far, pick-up might
be next day.

9

summerholiday

Taking care ofchildren(insideand outside)
Taking care ofchildren･Check the injured children.
･There is fear of a fire because we use
the stoves.

Introduction of Disaster Imagination Workshop into Risk-Management Training for Nursery School Leaders 595

October 2009, Incheon, Korea

In PS-WS, participants wrote 304 cards (accident: 102, shivering event: 119,
uneasiness/questions/problems: 83). The risk described in the cards varied
in topics such as earthquake, accident, suspicious person invasion, allergies,
and bees. The number of cards collected concerning earthquake was 21 in
PS-WS and 77 in DI-WS. When we compared PS-WS and DI-WS,
problems written in DI-WS were more concrete and detailed than those of
PS-WS (Figure 4). In presentation time in DI-WS, presenters explained
peculiar contents due to the conditions of his/her group to understand thedifference of the situation by different condition (Table 1). We will arrange
the cards and the stories, and analyze the contents according to the type of
danger or various characteristics of parties and so on, and apply to design ofthe support system (proposed in chapter 4).
The 38 questionnaires of participants’ impressions were broken down into 3
categories – 22 were positive such as “I felt that the training under thevarious conditions are necessary”, 11 were negative such as “Time waslimited”, and 5 were both. Most of negative answers concerned about thetime scheduling. In the training, the discussion time exceeded 25min-40min
than that of what we had expected. Therefore, we had to shorten the time oflecture and presentation (Figure 5). We will redesign the time schedule ofthe training based on this result.
9o’clock

Writing “basic information of a nursery school” form
PS-WS (Problems Sharing Work Shop)

10

Lecture 15min / writing 10min / talking 35min / presentation 90min
±0min

11

＋5min

＋25min－30minLecture 15min / writing 15min / talking 60min / presentation 60min
introduction
writing
lecture

12
Lunch

13

talkingpresentation
break

DI-WS (Disaster Imagination Work Shop)
Lecture 10min / writing 30min / talking 30min / presentation 50min

14

±0min

±0min

＋40min－10minLecture 10min / writing 30min / talking 70min / presentation 40min

15

Conclusion
Lecture 35min / writing 15min / presentation 10min－15min16
scheduled actual

－6min

－9min

Lecture 20min / writing 9min / presentation 1min
Writing a conclusion poster

Figure 5: program (scheduled/actual)
In the questionnaires, we found some motivation such as "I want todownload the writing form of DI-WS". Moreover, few days after the
training, we got a mail from a participant that “we want to do DI-WS in our

596

New Technologies for Urban Safety of Mega Cities in Asia

nursery school”, and two nursery schools will do DI-WS in next October,2009. It shows possibility that DI-WS in the training for the leaders ofnursery schools may lead to the DI-WS in nursery schools.
Based on the situation explained above, we could conclude that there is thehigh possibility of expanding field of DI-WS approach by introducing DIWS into risk management training for nursery school leaders.

4. PROPOSAL OF THE DI-WS SUPPORT SYSTEMBASED ON THE RESULT OF THE TRAINING
For establishing a new DI-WS system in risk management training fornursery school leaders, it is necessary to build the WS support system. Firstof all, it is necessary to improve contents and time schedule of current DIWS and prepare the DI-WS training set by which a nursery school members
can carry out WS based on each characteristics by themselves smoothly.
Moreover, to answer the participant's question in WS, the lecturer should
know the knowledge such as the life patterns of the nursery school members,
besides the knowledge on disaster mitigation. Therefore, a support system to
get information and hints listed below is necessary.
･Various information which helps carrying out DI-WS･ Hints for solving questions and problems arisen from DI-WS
The system will be designed based on the data obtained from the DI-WS.
For updating the system, we will add the lessons learned from past disasterand accidents, and knowledge and comments by specialists, data from thefuture WSs. In the future, we will deal with the other risks besides theearthquake disaster, and make the support system for nursery schools by
which nursery schools can manage their total risks improving their risk
imagination.

5. CONCLUSIONSIn this paper, we attempted to introduce a Disaster Imagination Work Shop
(DI-WS) into risk management training for nursery school leaders. As thefirst step of the research, we picked up earthquake disaster as an example
from all risks that we should consider. We have designed a training program
composed of two workshops. The first half is Problem Sharing Work Shop
(PS-WS) concerning all risk issues, and the latter half is DI-WS based on
PS-WS. Then, we carried out this program and examined the possibility of
expanding DI-WS approach. Finally, based on this result, we listed up
problems for expanding this approach and proposed a DI-WS support
system. In the future, we will collect more data for the support system byconducting WSs and hearing surveys.

Introduction of Disaster Imagination Workshop into Risk-Management Training for Nursery School Leaders 597

October 2009, Incheon, Korea

REFERENCES
Abe, M., and Meguro, K., 2005. A proposal of disaster imagination Work
Shop (Meguro-maki WS) for improving total disaster reduction abilityof nursery schools and others, SEISAN-KENKYU –Report of theInsititute of Industrial Science, the University of Tokyo - 57, pp.538-542(In Japanese)
Abe, M., and Meguro, K., 2007. A study for improving total disaster
reduction ability of nursery schools and kinder gartens, 2007 New
Technologies for Urban Safety of Mega Cities in Asia, pp.521-528.

598

New Technologies for Urban Safety of Mega Cities in Asia

Application of Analytic Network Process to
Design Emergency Capability
Assessment Index System
SHEN SHIFEI，CHU YANYAN，DU LIGANG，QIAO LIFENG, YANG RUICenter of Public safety Research, Tsinghua University, Beijing, China
chuyan@mail.tsinghua.edu.cn

ABSTRACT
In order to develop emergency capability assessment objectively andimpartially, emergency capability assessment index system should beestablished comprehensively. Emergency capability assessment elements
are summarized based on the analysis of Chinese emergency response law.
Emergency capability assessment index system network model is establishedusing the analytic network process method and index weight are calculated
according to the importance of all indexes, by mean of which,independence relation of elements in the different group is embodied. Inorder to verify the objectivity of ANP method, study on emergency
capability assessment index system of a city in north china has beendeveloped and the global weight result shows the priority of every element.
1. INTRODUCTIONAs SARS crisis in 2003, Indonesia tsunami in 2004, Paris mass riots inFrance in 2005, London blast in England in 2006, natural disasters, manmade disasters, public health emergency, social security and other incidents
occur frequently and pose a serious threat to life, property, social order andeconomic development. Governments are making efforts to improve
emergency management capabilities to reduce consequence caused byvarious incidents.
ECA can help making emergency management system more solid, flexible
and efficient. It also provides a reliable basis for emergency capability
development. Considering the characteristics of incidents, such as diversity,
complexity, abruptness and unexpectedness, etc, it is difficult to make anobjective and impartial emergency capability assessment. As the key toreflect the level of assessment object, it is important to establish acomprehensive emergency capability assessment index system.
At present, emergency capacity assessments have been developed in somecountries. The U.S. state and local governments develop emergency
management response preparation capability assessment. Japanese local
public organizations develop disaster prevention capacity and crisis599

October 2009, Incheon, Korea

management capability assessment. Those assessment projects adopt Delphi
method, Set-value Iteration method, Analytic Hierarchy Process (AHP) andother methods. As AHP method, weight determination is only considereddominant role of the upper elements on the lower elements and suppose thatelement in the same level is independent with each other. In fact, emergency
capacity assessment elements are mutually affected.
In this paper, analytic network process method（ANP）is used to establish
emergency capability assessment index system, in which not only impact bylower elements on upper elements but also relation of elements in the
different group can be represented by the assessment index weight.
2. Emergency Capability Assessment Elements
Emergency capacity assessment index system development is a systematic
project and need to analysis and quantify various emergency functions.
Emergency capacity assessment index system should involve many
elements such as law, medical, communications, logistics and equipment,
etc. "Emergency response law" is a complete description of the incidents
emergency elements and emergency functions and it is Chinese mostauthoritative legal basis for emergency management. Through analysis of allclauses in the emergency response law can be establish a morecomprehensive emergency capability assessment index system.
Be consistent with the ‘Law of the People's Republic of China on
Emergency Response’, our ECA index system consists of three levels. Eachlevel contains a number of elements such as laws and regulations, risk
analysis, hazard prevention and mitigation, emergency organizational,
emergency plan, etc. The first level is the emergency capability ofassessment object. The second level is the four-stage emergency
management process. The third level is emergency capabilities involved in
the stages. ECA index system not only represents the emergency
management process, but also covers all aspects of emergency management.
(1) Emergency Prevention and Preparedness Capability
Emergency prevention and preparedness is the basis of emergency
management. It lies in six aspects: laws and regulations, emergency plan,
emergency resource, risk analysis, emergency education and exercise,emergency team.
(2) Monitoring and Prediction Capability
Monitoring and prediction capability is the precondition for emergency
preparedness and response. It lies in three aspects: incidents prediction,
emergency information report and emergency information monitoring.
(3) Emergency Response and Rescue Capability
Emergency response and rescue capability is the key part of emergency
management. It can prevent incidents spreading and derivative events

600

New Technologies for Urban Safety of Mega Cities in Asia

developing and lies in four aspects: emergency response, emergency
command, emergency organization, emergency information publishing.
(4) Recovery and Restoration Capability
Recovery and restoration means recovery production, work and social orderas soon as possible. It lies in four aspects: emergency disposal, recovery andrestoration, incident assessment and investigation, reward and punishment.
All elements of emergency capability assessment index system are list in
Tab. 1.
Tab.1 Emergency Capability Assessment Index System Elements
Evaluation
Element Group
Element
objectlaws and regulations
emergency plan
emergency resource
Prevention and Emergency risk analysis
Preparedness Capability
emergency

educationandexerciseemergency teamemergency monitoring
Emergency
Capability

Monitoring and Prediction emergency information report
Capability
incidents prediction
emergency response
emergency command
Emergency Response andRescue Capability
emergency organization
information publishing
emergency disposal
recovery and restoration
Recovery and Restoration incident
assessment
Capability
investigation

andreward and punishment
2. Emergency Capability Assessment Index System
The ANP developed by Thomas L. Saaty (1996) of University of Pittsburgh,
is a theory of measurement generally applied to the dominance of influenceamong several alternatives with respect to an attribute or a criterion. It canbe used as a risk evaluation model. It has the advantage of utilizing
qualitative, as well as quantitative. The ANP allows us to quantify important

Application of the Network Analysis Process to Design Emergency Capability Assessment Index System

601

October 2009, Incheon, Korea

factors, considers whether a factor influences another or is influenced byanother, that is to say, dependence and feedback. So, ANP was chosen to
research the effect of all elements in emergency capability assessment index
system.
Using ANP method ， emergency capability assessment index systemelements are sorted into two layers. The first layer is emergency
management capability. The second part is network layer. Each elementmeans one aspect of emergency management. There are totally four element
groups, C1 , C 2 , C 3 , C 4 , which are emergency prevention and preparedness
capability, monitoring and prediction capability, emergency response andrescue capability, recovery and restoration capability and seventeen
elements, ei1 , ei 2 , L, ein i . Every element plays a different part in theemergency response and management, which means every element has adifferent weigh in the index system. Emergency capability assessment index
system is shown as Fig.1.

Prevention andEmergency Preparedness
Capability

Emergency Response
and Rescue Capability

Monitoring andPrediction Capability

Recovery and
Restoration Capability

Fig. 1 Management Capability Assessment Index system
Since there are too many uncertain factors, it is very difficult to get theelement weight directly. Element weight will be calculated as follow
calculation program.
(1) Element e jl in group C j is used as the criteria. Judgment matrix can beestablished according to comparison between two elements in group Ci .
(2)Vector ( wi1jl , wijl2 , L , winjli ) T is got through calculating characterize root of
judgment matrix. Similarly, vector is calculated using other elements ingroup C j . Then, Wij can be constructed, shown as equal (1).
⎡ wi1j1⎢ j1w
Wij = ⎢ i 2⎢ M⎢ jn j⎣⎢ wini602

wi1j 2wij22
M
jn
wini jjn
L wi1 j ⎤jn ⎥L wi 2 j ⎥
M
M ⎥
jn ⎥
L wini j ⎦⎥(1)

New Technologies for Urban Safety of Mega Cities in Asia

Column vectors of Wij representation impact by elements in group Ci on
elements in group C j . If there is no connection between elements in groupC j and elements in group Ci , Wij will be 0.
(3) Super matrix W is got through synthesis of all Wij , shown as equal (2).
L w1N ⎤
L w2 N ⎥⎥
(2)
M
M
M ⎥
⎥
w N 2 L w NN ⎦Super matrix W is anti-negative matrix. Wij is a sub-block of super matrix⎡ w11⎢w
W = ⎢ 21
⎢ M
⎢
⎣wN 1

w12
w22

W and it is column normalization.
(4) Get weighted matrix A . Comparing between two different groups,
judgment matrix is established as follow.

Cj

C1 C 2 … C N

C1
C2
…
CN

c11

c12 … c1N

c11

c12 … c1N

… … … …
c11 c12 … c1N

Through calculating characteristic vector, weight matrix A is got as equal (3)⎡ a 11 L a1N ⎤(3)
A = ⎢⎢ M
M ⎥⎥⎢⎣a N 1 L a NN ⎥⎦(5) Weighted super matrix W is got through weighting super matrix Wij asequal (4).

W = aij Wij ,i = 1,L, i ; j = 1,L, j(4)(6)In a weighted super matrix W , wij is one step dominance, which means
influence of element eil to element e jl . Two step dominance can be got
using equal (5)nW 2 = ∑ wik wkj

(5)

k =1

If W ∞ = lim W t can be got, j column vector of W ∞ means limiting sortt →∞vector, which is relative element e jl .
4 Application of Emergency Capability and Results Analysis

Application of the Network Analysis Process to Design Emergency Capability Assessment Index System603

October 2009, Incheon, Korea

Our method has been applied to the emergency capability assessement of amega-city in north China to demonstrate the application of ANP. The
emergency capabilities assessment index weight is calculated to analyze
relationship of assessment elements.
4.1 Judgment Matrix Establishment

Various indexes have different influence on emergency capability.
According to 1~9 scale rule, judgment matrix can be established to calculate
their weights. Emergency capacity assessment index judgment matrix
determination process is shown as Fig.2.

Fig.2 comparison between two factors
4.2 Element Weight Determination Using SuperDecisions Software

Fig. 3 construct network model

Emergency capability assessment index weight calculation is complete bySuper Decisions. First, emergency capability assessment index system
network model is established using Super Decisions software, as Fig.3.
Global super matrix is calculated using Super Decisions software after
judgment matrixes are input into network model. According to ANP, global
super matrixes should be weighted. Comparison matrixes between different
two groups are calculated as weighted matrixes. Then, weighted super

604

New Technologies for Urban Safety of Mega Cities in Asiamatrixes are got through multiplying non-weighted matrix and weighted
matrix. Finally, stability calculation can transform the weighted supermatrixes to the limiting super matrix, which means index global weight,
shown as Tab. 2.
The global weights embody interdependence relation of assessment indexes.
Priorities are calculated based on comparison of two indexes not only insame group but also in different groups. From Tab.2, it is shown that index“emergency response” has maximum priorities in assessment index system.
Tab.2 Global Weight Result
Element
laws and regulations
emergency plan
emergency resource
risk analysis
emergency education andexerciseemergency teamemergency monitoring
emergency
information
reportincidents prediction
emergency response
emergency command
emergency organization
emergency
information
publishing
emergency disposal
recovery and restoration
incident assessment andinvestigation
reward and punishment

Priorities
0.22175
0.19330
0.07892
0.06787
0.263630.174540.133420.657290.20929
0.466800.188100.19176
0.15333
0.47004
0.29203
0.19826
0.03967

5 Conclusion

Since the indexes of emergency capability assessment system are closely
related to each other, index weight cannot be obtained by simple
comparison. The application of ANP method to setup a emergency
capability assessment index system shows that by using ANP method, theglobal weighted index can be achieved, which is determined not only byrelationship between the same group but also by all the elements in different
groups.
ACKNOWLEDGEMENT

Application of the Network Analysis Process to Design Emergency Capability Assessment Index System605

October 2009, Incheon, Korea

This research is supported by National Science and Technology Program(Grant No. 2006BAK04A08) and National Nature Science Foundation ofChina (Grant No. 70973063).
REFERENCES

2006. Chinese Incident Emergency plan
2007. Chinese Emergency Response law
Federal Emergency Management Agency, 1997. State Capability
Assessment for Readiness. A Report to the United States Senate Committee
on Appropriations
ZHENG Shuang-zhong; DENG Yun-feng, 2006. Capability assessment
system for urban emergency incident readiness and its application. Journalof Liaoning Technical University, 12：943~946
Saaty, T.L. and Vargas, L.G, 2000. Models, Method, Concepts andApplication of the analytic Hierarchy Process. Boston: Kluwer Academic
Publishers
Saaty, T.L, 1980. The Analytic Hierarchy Process. New York: McGraw Hill.
1~20
Michael K. Lindell, Carla S. Prater and Ronald W.Perry, 2007. Introductin
to Emergency Management. New York: John Wiley & Sons, Inc,. 386~415
Florida Emergency Preparedness Association. Local Capability Selfassessment and Accreditation Tool, 2001
Huang Dianjian, Wu Zongzhi, Cai Sijing, Jiang Zhonghan, 2004.
Comprehensive Assessment of Emergency Management Capacity to Urban
Major Accidents. Proceedings of 2004 International Symposium on Safety
Science and Technology, Shanghai, Beijing: Science Press.
WANG Liang fen, 2001. The Theory and Algorithm of Analytic Network
Process, Systems Engineering-theory & Practic : 3, 44-50

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New Technologies for Urban Safety of Mega Cities in Asia

EMERGENCY RELIEF DELIVERY WITH
DEMAND CONFLICT COORDINATIONAND GOAL SOFTENINGZHANG JING, SHEN SHIFEI, YANG RUIDepartment of Engineering Physics, Center for Public Safety Research,
Tsinghua University, China
jing-zhang05@mails.tsinghua.edu.cn

Abstract
Large scale disasters usually lead to great damage of multiple regions andcause the sharp increase of relief consumption. When the relief supply could
not meet the needs of multiple regions at the same time, there is the demand
conflict for the limited relief among regions involved. Emergency decision
maker should take into account the response time, the cost and the delivery
fairness to develop appropriate relief delivery plans. Because it is usuallydifficult to achieve simultaneously the optimization of multiple objectives ofdecision making under disaster cases, the goal of emergency decision
making is needed to be soften from seeking the optimal solution to looking
for acceptable solutions. This paper presents the relief delivery model withdemand conflict coordination and goal softening to make the efficientdelivery for a multi-regional, multi-factor and multi-criteria emergency
resource allocation. The integrated model is developed based on demandmodel, delivery model and assessment model with comprehensive analysis
of affecting factors.
Keywords: emergency resource allocation; relief delivery; demand conflict;goal softening in emergency; cross-regional coordination

1. INTRODUCTION
Large scale disasters, including natural disaster and man-made catastrophe,
usually involve multiple regions and lead to great damage and lots offatalities. The Indian Ocean earthquake and tsunami involved 12 countries
and more than 200 thousand of death. The technical disaster in the northeastof China, the double benzene plant explosion on November 13, 2005,
released hundreds tons of benzene pollutants into the Songhua River andcaused large-scale disruption of water supply. The urgency inherent of607

October 2009, Incheon, Korea

disasters and multiple regions involved make the emergency relief be
consumed very fast so brings lots of challenge for decision making. Whenthe relief supply could not meet the demands of multiple regions at the sametime, the demand conflict for the limited relief exists among multiple
regions. Governments should not only consider the response time and thecost to develop the relief delivery plans, but also balance the fairness ofdelivery among multiple regions involved to make the right decision.
However, it is usually difficult to achieve simultaneously the optimization ofmultiple objectives of decision making.
As one of key issues of emergency decision making with complexity,
there is an increasing research in emergency resource allocation and relief
delivery. Fiedrich et al. (2000) investigate the modelling of emergency
resource allocation for earthquake disasters. Fiorucci et al. (2004) develop a
dynamic model of allocation to achieve real time control of forest fires.
Chang et al. (2007) research the flood emergency logistics preparation
problem under uncertainty. Willis (2007) investigates the emergency
resource allocation for terrorism events. Lodree and Taskin (2009) develop amodel wind speed information updates for hurricane response. The models
with mathematical programming, such as integer programming and goal
programming have general applications in resource allocation (Wei andOzdamar, 2007), like for first response organization deployment (Taylor etal., 1985; Basu and Ghosh, 1997; Sharma et al., 2007).
Although recent literature investigated many important and interesting
issues in emergency relief delivery, there are challenging problems existingin real emergency response. The challenges includes: 1) The investigation
on demand model. The models of demand estimation should be developedwith comprehensive consideration of affecting factors. 2) The dynamic
network of supply and demand of emergency relief. With the development
of disasters, the regions involved, the storage of relief supply, the risk oftransportation and the amount of demand probably change so the dynamic
models need to be studied. 3) The coordination of demand conflict. The
decisions should be made not only aiming at the optimization of total timeor cost, but also taking into account the restriction of supply and demand
among each regions and the distribution fairness under demand conflict. 4)
The goal softening in emergency decision making. It is usually difficult toachieve the optimal solutions in the face of the urgency and complexity ofdisaster condition. The goal softening is a soft approach for solving
complicated optimization models. Lau and Ho (1997) explain the goalsoftening concept in ordinal optimization. The basic idea of goal softening is
to look for a good enough solution instead of an optimal solution. The goalsoftening in emergency decision making is an approach to soften the goalsof emergency plan and response to the acceptable solutions under disastercases.

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New Technologies for Urban Safety of Mega Cities in Asia

2. THE FRAMEWORK
2.1 Comprehensive analysis of affecting factors
The relief delivery network is composed of regions involved, relief
warehouse, transfer areas and routes. The risk of these elements is affectedby various factors so change continuous with the development of disaster.
To achieve the real time demand analysis of emergency relief, it is necessary
to investigate the static states of the relief delivery network such as thevariety of relief and the amount of storage, and development of the relief
delivery network such as the availableness of relief and the destruction ofroutes.
2.2 Identification of relief demand conflict
As a common issue in emergency resource allocation, the demand
conflict exists in two dimensions: the supply shortage of scarce resource
caused by the sharp increase of consumption and the relief priority ofregions involved. The analysis of the severity of disaster and the realaffection of each region is needed. The standard of demand satisfaction
should be conformed according to requirement of decision maker to define
what a good enough solution is. The priority of regions should be evaluatedand ranked comprehensively to establish an appropriate method for
coordinating relief conflict.
2.3 Softening and assessment of objectives
Considering the extreme condition of disasters, the acceptable solutions
instead of optimal solutions are looked for to soften the goals of emergency
decision making. The trade-off of multiple objectives should be made,including to minimize emergency response time, to mitigate the risk duringtransportation, to distribute fairly, to minimize cost and waste, to balance thekinds of relief and so on. It is difficult to optimize all the objectives ofdecision making so it is important to develop the utility function of goalsoftening and corresponding assessment approach.
The analyse procedure of emergency relief delivery is shown in figure 1.

Emergency Relief Delivery with Demand Conflict Coordination and Goal Softening609

October 2009, Incheon, Korea

Demand Estimation
Disaster Data Analysis
Demand Analysis

Dynamic Adjustment
Disaster Development
Assessment
Satisfaction Analysis

Goal Softening
Objective Establishment
Acceptability Analysis

Supply Estimation
Relief and Storage Analysis
Transport Risk Assessment

Conflict Coordination
Demand Conflict Analysis
Priority Analysis

Figure 1: The analyse procedure of emergency relief delivery

3. THE MODELS
3.1 Multi-regional demand model
It is needed to integrate the static and dynamic factors impacting
supply and demand to establish demand model. The static factors we focus
on in this paper include: Affected area related factors
Regional geographic feature, regional population distribution,
regional critical infrastructure, the distribution of key target forprotection, etc.
 Relevant factors of relief supply
Relief type, functions, storage sites, storage quantity, etc.
 Transport pathway related factors
Road conditions, traffic conditions, vehicles type, etc.
 Relief object related factors
Basic requirements, the minimum requirements, special needs, etc.
The dynamic factors include: Factors that affect the risk of the affected region
Development of events, the possibility of secondary disasters, etc.
 Factors that affect supply
relief availability, substitutability, etc.
 Factors that affect the risk of transport pathways
Road damage, road repair efficiency, transportation alternatives,protection states of power, etc.
 Completeness of information

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New Technologies for Urban Safety of Mega Cities in Asia

Judgement and filter of pseudo-demand and repeated demand, etc.
 Relief object factors
Historic satisfaction degree of demand, expectations of demandsatisfaction, satisfaction in reality, etc.
3.2 Delivery model under demand conflict
Firstly it is necessary to determine the intensity of disaster and theareas impacted. With the analysis of the probability of destruction of
warehouses and network, the risk analysis for availability of relief andtransport will be made to establish the mode of relief delivery model underdemand conflict game. In the dynamic game with incomplete information,
the relief needs of regions are considered as strategies, based on different
coordination mechanisms. The existence of multiple equilibria allows obtain
multiple feasible plans at the same time to support emergency decision morecomprehensively.
The analysis of possibility and severity of demand conflict should be
combined with the regional priority and the relief need satisfaction
investigated in demand model. A classification approach is used tocoordinate regional conflict. For relief that can be partitioned in quantity,
such as food, drinking water, quilts, tents, etc., the equity in distribution ofshould be regarded as these supplies are related to daily life closely. For
relief that could not be partitioned, such as large equipment for rescue andco-workers required, it is needed to determine the priority of regions withseverity of damage and availability of transport to minimize the disasterlosses and achieve the rescue effectiveness.
3.3 Dynamic assessment model
The determination of multiple objectives should be combined with thepractical needs of emergency decision-making for the multi-regional,
multi-factor deployment problem. The trade-off for the allocation fairness,
the time and the cost of response is made to establish a rational utility
function and assessment method of acceptable solutions. The dynamic
adjustment of deployment is carried out by communicating with actual
decision-making needs of emergency manager and development ofdisasters.
The architecture of the integrated model is shown in figure 2.

Emergency Relief Delivery with Demand Conflict Coordination and Goal Softening611

October 2009, Incheon, Korea

Disaster Data
Relief Availability
Route Availability
Information Reliability

Multi-factor Analysis

Regions Involved
Relief Object
Relief Storage
Route and vehicle

Relief Supply
Network Analysis

Demand Modelling

Relief Priority
Demand Satisfaction

Conflict Analysis

Response Time
Delivery Cost
Distribution Fairness

Goal Softening
Dynamic
Adjustment
Delivery Solution

Figure 2: The integrated model architecture

4. CONCLUSIONSThe urgency and complexity of disasters make the efficient delivery of
emergency relief a challenge in emergency decision making. There areusually multiple regions to be involved in large scale disasters and the sharp
increase of consumption of relief may lead to regional demand conflict. This
paper presents the framework for multi-regional, multi-factor andmulti-criteria relief delivery modeling of emergency resource allocation. In
the future, simulations incorporated with GIS data will provide a reality
environment for analyzing and assessment the emergency relief delivery.

ACKNOWLEDGEMENT
This research is supported by National Nature Science Foundation of China(Grant No. 70973063) and National Science and Technology Program(Grant No. 2006BAK04A08).

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New Technologies for Urban Safety of Mega Cities in Asia

REFERENCE
Basu, M. and Ghosh, D., 1997. Nonlinear goal programming model for the
deployment of metropolitan police patrol units. Opsearch 34(1): 27-42.
Chang, M. S., Tseng, Y. L. and Chen, J. W., 2007. A scenario planningapproach for the flood emergency logistics preparation problem under
uncertainty. Transportation Research Part E: Logistics and Transportation
Review 43(6), 737-754.
Fiedrich, F., Gehbauer, F. and Rickers, U., 2000. Optimized resource
allocation for emergency response after earthquake disasters. Safety Science35, 41-57.
Fiorucci, P., Gaetani, F. and Minciardi, R., 2004. Dynamic models for realtime control of forest fires. Proceedings of the 15th International Workshop
on Database and Expert Systems Applications.
Lau, T. W. E. and Ho, Y. C., 1997. Universal Alignment Probabilities andSubset Selection for Ordinal Optimization. Journal of Optimization Theory
and Applications 93(3), 455-489.
Lodree, E. J. and Taskin, S., 2009. Supply chain planning for hurricane
response with wind speed information updates. Computers and Operations
Research 36(1), 2-15.
Sharma, D. K., Ghosh, D. and Gaur, A., 2007. Lexicographic goal
programming model for police patrol cars deployment in metropolitan cities.
International journal of information and management sciences 18(2),173-188.
Taylor, B. W., Moore, L. J., Clayton, E. R., et al., 1985. An integer nonlinear
goal programming model for the deployment of state highway patrol units.
Management Science 31(11), 1335-1347.
Wei, Y. and Ozdamar, L., 2007. A dynamic logistics coordination model for
evacuation and support in disaster response activities. European Journal ofOperational Research 179, 1177-1193.
Willis, H. H., 2007. Guiding Resource Allocations Based on Terrorism Risk.
Risk Analysis 27(3), 597-606.

Emergency Relief Delivery with Demand Conflict Coordination and Goal Softening

613

PARALLEL SESSION 10

REGIONAL FLOOD RISK MANAGEMENT
IN KOREA1BYUNG HA SEOH, 2BYUNG SIK KIM and 3DAE WON JANG
1

Department of Civil and Environmental Engineering,
INHA University, Incheon, Korea
seohydro@inha.ac.kr
2
Water Research Division,
Korea Institute of Construction Technology, Korea
hydrokbs@kict.re.kr
3
Department of Civil and Environmental Engineering,
INHA University, Incheon, Korea
hydrojdw@naver.com

1. INTRODUCTION
Although many regions in South Korea became urbanized through thegrowth-centered urbanization in the 70s to 80s, there were many regionsthat were developed randomly without necessary verifications on various
parts. In recent, new cities and urban districts are being developed centeringon quality of life from growth through the planning on various
environmental aspects such as education, society and economy, but theexisting cities and old urban districts are deteriorating thereby causing
regional imbalance.
Such imbalance is not limited to just visible things such as roadsystem or social infrastructure but applied to natural disasters such as
landslide. The blow figure shows the aspect of flood damages that are
occurring recently. As shown in the figure, personal casualties and floodarea are decreasing but property damages are rapidly increasing. Such rapid
increase of damages results from the population concentration and industrial
foundation and properties concentration according to urbanization andindustrialization.

Figure 1: Flood damage trend of Korea

615

October 2009, Incheon, Korea

Also, it is because the existing facilities for preventing natural
disasters are not fully functioning at the increase of the degree of intensityof localized torrential downpours and typhoons resulting from the abnormal
weather phenomenons that are occurring frequently in recent. For suchreason, appropriate response measure strategies must be established to
improve comprehensive disaster prevention function in cities. Namely, there
is a need for methodological study and to provide practical services that canbe utilized in preventing, preparing for and responding to natural disasters
based on quantitative evaluation of the natural disaster prevention capabilityof the existing cities from the aspect of disaster risk management.
From such perspective, this study overall reviewed the effects ofclimate change on flood damage and, especially, it forecasted the effects offlood risk management in cities. Lastly, it mentioned adaptive policy plansto respond to abnormal flood from the climate change in future.

2. CHANGES FROM CLIMATE CHANGE
2.1

The Present Condition of Disaster Occurrences in Korea

In Korea, the trend is that the frequency of severe weather such as
typhoon is increasing from the temperature increase since the late 1980s andthe frequency of torrential rain disaster occurrence in summer season isincreasing from in the annual average of 5.3 times (1940~1970) to 8.8 times(1980~1999). Especially, damages from localized torrential downpour
continuously occurred between 1998 to 1999, and, in Ganghwa and Paju
regions, the downpour amount equivalent to 70% of the annual precipitation
amount in 3 to 4 days caused damages such as flooding of farmland andproduction facilities and sweeping away social overhead capital. After 2000,
the economic damages from weather disaster such typhoon rapidly
increased, and the damages from the typhoon 'Lusa' in 2002 and 'Maemi' in
2003 were respectively 5,469.6 billion won (124 deaths, 60 missing and
88,625 victims) and 4,781 billion won (117 deaths, 13 missing and 10,975
victims). Although it is difficult to state that such localized torrential
downpours and floods occur strictly from the climate change, it is true thatthe characteristic of extreme situation of precipitation in the Korean
peninsula is changing from the climate change. According to theannouncement by Korea Meteorological Administration, the temperature of
our country has increased 1.5℃ during the 20th century and the number ofrainy day decreased 14% while the precipitation amount increased 7%
during the past 20 years and the frequency of torrential downpour of over
80mm increased. Such change of extreme precipitation characteristics cancause changes in human lives and ecosystem and, especially, it will haveeffects on flood frequency and size.

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2.2

Change of Paradigm from Climate Change

In general, the risk of water related disasters can be expressed bymultiplying the three elements of 'hazard' that displays the probability ofdisaster occurrence, 'exposure' of economic properties or human lives thatare located within disaster risk region and 'vulnerability' that signifies thelack of protection ability.

Figure 2: Flood Risk Management
Thus far, the main purpose of water management has been themaintenance of living and production foundation and it basically controlledwater supply through water resource development. For floods, it basicallyplanned, designed, managed and operated flood control facilities throughwhich planned flood amount can be accommodated and controlled by
setting it using reproduction probability as the basic index. However, such
response alone can no longer satisfy every demand of the era that includes
future climate change and preservation of environment and ecosystem. Also,
there is a need to prevent future problems from surfacing or preventing themfrom expanding in their degree of risk by introducing risk management
techniques related to excess flood and reviewing planning method or facility
capacities.
As mentioned earlier, very large amounts of precipitation are
frequently occurring and floods in excess of planned frequency are
frequently occurring and, even though the flood area and personal casualties
are decreasing from the river and water system maintenance project that has
been continually implemented, our living spaces are nearing closer andcloser to river for production and living and the geographical change fromurbanization is increasing the amount of flood damage per unit area by
increasing the vulnerability to flood risk.
This signifies that the current flood defense measure has reached its
limitation, and it reveals the need for a new flood control measure to
respond to the recent phenomenons such as unexpected flood and abnormal
floods since the flood control through dam and levee for the past 30 to 40
years can only assure the basic flood control safety. There is a need to
Regional Flood Risk Management in Korea

617

October 2009, Incheon, Korea

convert the paradigm established by flood defense measure from theconcept of surface of drained area to line concept of river into region or
district unit flood control measure. This signifies the need to convert thecurrent flood control measure being implemented centering on flood control
facility of levee into potential damage region around river centered flood
control measure. The need for regional measures in potential damage
regions is being raised that can consider the characteristics of the region interms of its weather, geography and socio-economic since there arelimitations with the construction of river centered levee in thediversification of flood control measure.

3. THE LIMITATIONS AND PROBLEMS OF THE EXISTINGFLOOD DEFENSE MEASURES
3.1 Unplanned River Maintenance According to Rapid Progress of
Urbanization
In our country, the urbanization has been rapidly progressing throughits economic growth. In the case of Seoul, it also changed from water
permeable surface such as undercurrent, forest with high permeation
function and paddies and dry fields to impermeable paved region that hardly
has any undercurrent or permeation ability at the development from
population concentration. The possibility of flood damage risk increased
from the occurrence of the development of relatively inexpensive riversurrounding region without the review of flood control during the process of
housing development, industrial complex development or commercial
facilities development.
Especially, in the case of regional grade 2 rivers, they are not being
well maintained compared to national rivers. The rivers with establishedriver maintenance basic plan is only about 45% thereby the irrigation ofriver and its flood control measure have not been properly established.
Therefore, flood damages are repeatedly occurring from the insufficientmaintenance of river width and levee section and budget is being wasted as
the flood damage recovery is being implemented centering on restoration tothe original state instead of improvement restoration. Also, the current
circumstance is that the connectivity of the entire area drained is insufficientfrom the dispersed implementation of various flood control projects such asdam, levee, water supply pump facility and debris barrier according toauthorities and projects and the damage risk is being added from the river
maintenance focusing on structures such as levees.
3.2 Lack of Disaster Prevention Facilities and Standardized RiverManagement Focusing on Flood Control
The general disaster prevention facilities that can be commonly seenin our country are the facilities that control flood amount to prevent internal
flood by discharging water when external water level is lower than internal

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New Technologies for Urban Safety of Mega Cities in Asia

water level according to the difference between the two by holding a part of
influx amount gathered in the low land around river during floods. However,flood control is being implemented only through the combined form ofminor house modification and pump facility in most of urban regions since
assuring appropriate areas of undercurrent land is difficult from the increaseof land price from the development.
Also, the standardized occurrence of the installation of concrete shore
protection and development of river terrace land in the maintenance of river
without considering the characteristics of the river is not only deteriorating
the surrounding environment of the river and utilization level of theresidents but also adding the risk of flood. Therefore, there is a need todevelop and manage rivers according their characteristics.
3.3 Levee Focused Flood Defense Policy
The flood control policy of our country thus far can be simply
summarized as the attempt to stop flood through levees. This resulted fromthe intent to solve the problem of flood within rivers by building levees atrivers to maximize the land usage according to economic development since
the usable area is lacking in our country. However, it is causing the side
effect of increasing the possibility of flood occurrence through theconcentration of population and properties at the downstream from therepetition of the enlargement construction of levees to prevent flood
damages resulting from the expansion of urbanization around river and theenlargement of peak flood amount from excessive construction of levee atthe upper stream from the continuous river levees from the upper stream todown stream. However, as mentioned earlier, the personal casualties
decreased in spite of the flood control policy that has been continually
implemented for the past 30 years based on such foundation, but the error of
the existing flood control policy can be pointed out from the fact that theamount of flood damage is increasing exponentially. Namely, levee centered
flood control policy has fundamental limitations. As shown in Figure 3,
when a flood occurs in a natural condition, A community becomes flooded
as well as B community, but, in the case of constructing levees in A
community to stop flood (defended condition), B community can potentially
receive damages from even bigger flood even though A community might
be safe from it from the undercurrent of the flood in A community.

Regional Flood Risk Management in Korea

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October 2009, Incheon, Korea

Figure 3: Showing the outline of the risk of flooding
Although the current flood control measure is occurring centering on
administrative district, the problem is occurring of increasing flood damage
from the lack of selective defense from flood damage in the administrative
district centered flood control measure. Therefore, discussions among theregions within river areas must occur to effectively stop flood according to
the characteristics of river.
Although the levee centered flood prevention policy is being
perceived as an efficient option in the aspect of cost, the flood prevention
measures besides levees can be more effective when considering theenvironmental and economical aspects. Therefore, there is a need to share
the burden of flood in the entire river regions by developing flood
prevention policy besides levees to stop such ill practice. Namely, there is aneed to develop unique and own flood measure that is suitable to thecharacteristics of the region such as undercurrent land, riversideundercurrent land, flood control land, and flood control channel. Also, there
is a need to divide the flood burden by reducing impermeable region incities and assuring flood undercurrent spaces such as playing field, park,
small scale undercurrent land.

4. THE EFFECTS OF CLIMATE CHANGE ON FLOOD CONTROLThe increase of precipitation amount and intensity from climate change hasenormous effects on flood structure such as dam. Since enormous damages
can be caused to the lower stream areas of a dam when it breaks, probablemaximum precipitation needs to be considered when designing a dam. In
general, the probable maximum precipitation increases about 10% when thetemperature increases by 1℃. To presume that the temperature increases by
1℃～2℃ from the climate change, it is fully possible that the probablemaximum precipitation increases more than 10%.

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New Technologies for Urban Safety of Mega Cities in Asia

Since the climate change changes the extreme floodgate phase that is
the most important variable in designing flood control facilities, the fact thatthe flood control technicians that plan and design flood control related
infrastructure need to consider climate change is becoming a reality. Also,
the gradual change effect of floodgate process from climate change is
expected to change the size and frequency of peak flood amount during thedesign period of flood control related infrastructure. The potential change of
future precipitation intensity will change the service level of flood control
related infrastructure and will require the change of design methodology
used in the planning of flood control related structure design.

Figure 4: Change of design frequency curve according to climatechangePicture 4 is a conceptual display of design frequency curve change offlood control structure according to climate change, and the blue solid line isdesign frequency curve using only the past information and the red dottedline shows the design frequency curve of future. As it can be seen from thefigure, the 10 year frequency design flood amount of the past will decreasein future to 5 year frequency design flood amount and, in the case of 100
year frequency design flood amount, it is showing the increase from the pastin the future and it can be found that the difficult of flood control could
increase from the reduction in the flood defense ability of the existing flood
control structure, namely, the reduction in flood control safety level.

5. THE OUTLOOK ON THE EFFECTS OF CLIMATE CHANGE
ON FLOOD DISASTER AND CONTROL IN THE KOREAN
PENINSULAIn this part, the outlook on the effects of climate change that has been
continually mentioned earlier on the occurrence of extreme precipitation in
Regional Flood Risk Management in Korea

621

October 2009, Incheon, Korea

the Korean peninsula. As the result of illustrating the tendency of climatechange by calculating the differences according to index of the present
future to consider the change in climate change, it was confirmed that thepropensity according to season and reason displayed clearly. According to
the climate characteristics of Korea, precipitation has been concentrating inthe summer season and the precipitation from typhoon during the lateAugust to September is continuing. Considering such seasonal
characteristics, the summer season (June～August) and fall season(September～November) were compared for the limit index related toprecipitation in this part. Figure 5-(a), (b) and (c) are respectively the criticalpoint of localized torrential downpour the displayed the degree that
corresponds to 90% from the day in which precipitation occurred, maximum
precipitation amount for 5 consecutive days that signifies precipitation when
torrential downpour continued for over 5 days and limit index result of the
future compared to the present for precipitation intensity.

summer season(6~8)

fall season(9~11)

summer season(6~8)

Figure 5-(a)summer season(6~8)

fall season(9~11)

Figure 5-(b)fall season(9~11)
Figure5-(c)As also mentioned in the previous paragraph, the frequency of
localized torrential downpour in the Korean peninsula is increasing from theclimate change and, accordingly, design precipitation is changing. As the622

New Technologies for Urban Safety of Mega Cities in Asia

result of comparing the space distribution of the precipitation of the past
(until 2000) according to the reproduction period for the calculated design
precipitation degree (2001-2090) that took into account the climate change
by implementing frequency change analysis according to major points basedon A2 scenario, it was revealed that design precipitation increased in mostof the regions.
Also, it was forecasted that the flood risk will increase from thelowering of the frequency to in the average of 50 years for the current 100
year frequency design precipitation within the next 100 years. Figure 6 is aspatial display of the lowering of frequency in the 2031s to 2060s according
to climate change for the 100 year frequency design precipitation.
Design Rainfall Difference

60

40

20

40

20

60
40

38° N

100

10 0

80

90

60
60

40

80
60

40

40

70

80

60

40

60

60

60

80

40

60

40

80

10 0

40
60

35 N

60

50
100

40
10 0 80

10 0

10 0

80

80

40
60

°

60

128° E

10 0

80

60

30
20

Figure 6: Reduce spatial distribution of the design frequency at 100
year frequency

6. THE OUTLOOK ON THE EFFECTS OF CLIMATE CHANGE
ON FLOOD DISASTER AND CONTROL IN THE KOREAN
PENINSULA
6.1 Improvement of the Calculation Method of Design Precipitationthat Considered Climate Change
As analyzed earlier, it was confirmed that the extreme precipitation
characteristics in the Korean peninsula is changing from climate change andclimate change of the future can increase the design frequency and size. As
the effort to maximize the benefit of adaptation to the climate change andminimize the negative effects of climate change, it can be said that adapting
to the effects of climate change on flood control structure is the stopping theincreasing flood risk and maintaining the services of the facilities. The
common method that is still being used in design has the premise of the factthat the future circumstance can be fully reflected from the climate
information of the past alone since climate does not change and thenormality of the mean and distribution of climate information no changing
Regional Flood Risk Management in Korea

623

October 2009, Incheon, Korea

according to time. However, it can be said that such design method with thepresupposition of the existing normality is the cause of the destruction ofmany flood control structures and deviating from the design scope.
Therefore, as mentioned earlier, we can no longer insist on the design floodamount calculating method based on the past records. The plan throughwhich the effects of the climate change of the future that is partially being
realized and displaying needs to be urgently researched and developed andefforts should be made to use it in actual work.

Figure 7: Considering climate change, water planning and design toimprove
6.2 Establishment of Custom-tailored Flood Defense Response Strategy
that Considered Regional Characteristics in Response to Abnormal
Flood
To perfectly protect from flood is impossible from not only technicalaspect but also economical and environmental aspect. Setting design
standards for protection is deception as well as trickery. Such standards
contradict every principle of controlling flood. It is because it is impossible
to generally estimate the power of extreme flood since the fluctuation fromclimate change is significant.
Whether or not to set up defense plan to protect from large-scale floodis also a dilemma. Its is because bigger damages can occur from theoccurrence of more extreme flood by reducing the damages from floods that
occur everytime. A prime example is the 'Great Flood of New Orleans' in
the U.S. that occurred in 2005 through which the limitation of flood control
ability of levees was recognized and the danger of the potential damage thatcan be brought forth from the collapse of levee was shown. Ultimately, thepotential risk of flood will gradually increase at river from the continuous
stacking up of levees even though the perception might be that risk at the624

New Technologies for Urban Safety of Mega Cities in Asia

river is decreasing from the levees that are continuously stacked up. In theplaces like Europe, including Germany, and Japan, the task of constructing
the flood control measure of a new concept has been persistently
implemented upon recognizing the risk of such levees. Therefore, thepossibility of failure at the occurrence of the flood that surpasses in its size
than the design standard needs to be presumed and its management needs tobe considered. Therefore, the recognition that every flood problem can't befundamentally solved only through the existing river channel centered flood
control measure is needed to respond to the external force that is increasingfrom the climate change and, accordingly, the introduction of a new "Roomfor the water" concept is needed through which the increased flood amountfrom the increased precipitation from regional development or climatechange is shared, and river area centered three dimension flood defense
control concept of line+surface+space, namely, integrated flood
management (IFM) from the river levee centered linear flood defense isneeded.

6.3 Multi-layered Flood Response Policy Establishment
In consideration of the increase of precipitation in the future, there is aneed to significantly increase design peak flood amount if the current flood
control safety level is to be maintained. However, it is extremely difficult toconstruct the facilities through which the increased flood amount is
controlled due to various conditions of limitation such as budget, humanresource and surrounding environment in which structures are installed,therefore, the limitation of the simple structural measure for flood measurefrom climate change is clear. Also, a very long time is required to complete
the construction of structure in general. Therefore, the flood response
measure the considered the climate change of the future needs to be multilayered. Namely, to satisfy the target flood amount, the traditional 'flood
response policy that assures safety in the level of river' that used to dependon river improvement and flood control structure installation and 'flood
response policy that assures the safety in the level of area' need to beestablished to respond to the possibility of excessive flood, namely, excess
flood.

Regional Flood Risk Management in Korea

625

October 2009, Incheon, Korea

Figure 8: Multi-layered Flood Response Policy Establishment
As the strategy for responding to abnormal flood, the strategy ofappropriate mitigation, adaptation and risks management non-structural
through non-structural approach is needed, along with structural analysis.
To establish such strategy, the areas that are vulnerable to flood need to be
identified and investments should be made for them first of all whenestablishing flood defense measure. Accordingly, there is a need to evaluate
on whether or not the social infrastructures related to flood such as alreadyinstalled levees, dam and river bridge possess design defense ability inresponse to abnormal flood that is caused from climate change.

7. SUMMARY AND CLOSING
Korea Meteorological Administration has decided to not forecast rainyspell that announces the start and end of rainy spell from this year. The
reason is from the fact that the precipitation patter in the summer season haschanged to the form of much rain before and after rainy spell at theacceleration of the global warming. However, considering the concentrationof 2/3 of the summer season precipitation from June to September and trendof guerilla style localized torrential downpour frequently occurring
regardless of the announcement of the rainy spell forecast, it can be said thatthe war against abnormal flood has just begun. Therefore, it can be said that626

New Technologies for Urban Safety of Mega Cities in Asia

our society is now at the point of trying to accept a new paradigm for flood
control.
However, the flood control measure of our country has not been able todeviate much from the existing frame. As mentioned earlier, the main
problems of the existing flood control policy can be summarized into thestandardized flood control measure from levee, uniform defense throughareas, administrative district centered river management and post-recovery
centered investment. To respond to the external force that is increasing fromthe climate change, there is a need for the perception that every flood
problem can't be fundamentally solved only through the existing river
channel centered flood control measure and diversification of flood control
measure is need. Accordingly, the introduction of a new "Room for thewater" that shares the increased flood amount from the increase
precipitation from regional development or climate change is needed andriver area centered three dimension flood defense control concept ofline+surface+space from the river levee centered linear flood defense isneeded.

REFERENCE
Communities and Local Government (2006). Planning Policy Statement: Planning andClimate Change –- Supplement to PPS1. Consultation
Gill, S., Handley, J., Ennos, R., and Pauleit,S. (2007). Adapting Cities for Climate Change:
the Role of the Green Infrastructure. Built Environment, 33(1): 115–-133.
IPCC. (2001). "Climate Change 2001; Impacts, Adaptations, And Vulnerability.
Contribution of Working Group II to the Third Assessment Report of the Intergovernmental
Panel on Climate Change.", Cambridge, UK and New York, NY, USA.
Kim, Byung Sik, Kim, Bo Kyung, Kyung, Min Soo, Kim, Hung Soo(2008), Impact
Assessment of Climate Change on Extreme Rainfall and I-D-F Analysis, Journal of Korea
Water Resources Association, Vol 41, Issue 4, April 2008. Pp. 379-394
Servat, E., et. al., 1999: De differents aspects de la variablilite de la pluviometrie en
Afrique del'Ouest et Centrale non Sahelienne. Rev. Sci. Eau, 363-387

Regional Flood Risk Management in Korea

627

A COMPARATIVE STUDY OF URBANVULNERABILITY BETWEENDHAKA AND TOKYO
MD. FAIZ SHAH
Doctoral Student, Department of Risk Engineering, Graduate School of
Systems and Information Engineering, University of Tsukuba, Japan
mdfaizshah@yahoo.com
OSAMU MURAOAssociate Professor, Department of Risk Engineering, Graduate School of
Systems and Information Engineering, University of Tsukuba, Japanmurao@risk.tsukuba.ac.jp

ABSTRACTThe objective of this study is to make a comparative study of urban
vulnerability between Dhaka and Tokyo by visual comparison with google
earth and main data analysis. Dhaka and Tokyo are two important
megacities in Asia characterized by big population, high density, rapid
urbanization, and increasing risk of big disasters like earthquakes. Both arevulnerable to earthquake and had big earthquakes in the past which hascome to the time of recurrence. But in terms of mitigation there is a big
difference between the two megacities. The possibility of recurrence of big
earthquakes in Tokyo like Tokai, Tonankai, Nankai and Tokyo Inland
earthquake is 70% in 30 years time. Learning from the big loss of the great
Kanto earthquake of 1923, Tokyo is promoting ‘safe city’ by improving theurban infrastructure like reconstruction of vulnerable houses, road
networks and evacuation places. On the contrary, the rapid urbanization
process of Dhaka did not concentrate much on to the risk of earthquake.
The primary reason is that, after the Great Indian Earthquake of 1897,
there was no big earthquake occurred in and around Dhaka. As per theshaking intensity data, the future earthquake estimation says that the same
earthquake will recur in the same area. This necessitates good level ofearthquake knowledge of the local people and earthquake resistantinfrastructure, urban planning, evacuation places, road networks tomitigate earthquake loss. But this type of practice is absent to a great extend,
and, which makes the people’s lives at risk in consideration of any
upcoming earthquake. Based on the circumstance and using the visualcomparison, main data analysis, and some specific criteria, it is found thatthe urban vulnerability is higher in Dhaka than that of Tokyo.

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1. INTRODUCTION
1.1 Background and Purpose:
Dhaka and Tokyo are two megacities in Asia with a high populationand density. Both cities are prone to natural disasters, which pose threat tourbanization. In the past, earthquake hit two cities and caused severe
damages. For example, the Great Indian earthquake of 8.7 affected Dhaka in
1897 and caused extensive damage to masonry structures (Al-Hussaini,2003). Recently Bilham and England (2001) cited that this earthquake willrecur and affect Dhaka at anytime. Another big event, the Bengal
earthquake of 7.0 generated near Dhaka and caused much destruction in
1885. This earthquake with its possible epicenter near Dhaka is of great
concern for a megacity like Dhaka. The earthquake damage and consequentcasualty risk of Dhaka is very high for its high population and large
percentage of unplanned buildings and structures. The earthquake risk index(EDRI) for Dhaka stands top among the 20 high risk cities in the world(Khan, 2005), mainly due to its inherent vulnerability of building
infrastructure (lacking earthquake resistant features), high population
density, and poor emergency response and recovery capacity (Al-Hussaini,2003). On the other hand, Tokyo had devastating earthquake in the past likethe great Kanto Earthquake in 1923, and has anticipation of big earthquakes
like the Tokai, Tonankai, Nankai and Tokyo Inland Earthquake in the next
few decades (Cabinet office, 2007). These are also of great concern forTokyo as the damage and casualty risk is very high. However, Tokyo hastaken several countermeasures to mitigate this earthquake’s impact. The
urbanization of two cities has inherent links with disaster vulnerability. This
paper checked the urban vulnerability status of two cities based on theirurban characteristics, disaster profile, and preparedness.
1.2 Data Used:
Two city’s outline data have been used at the beginning to show thecity characteristics. Then in the comparison section 3.1, population data of
two cities have been used. For both cities, population is one of the main
reasons for rapid urbanization. Section 3.2 showed the general disastermanagement outline of two countries. We found a similarity in disastermanagement framework of them. Both have same organizational framework.
But there is a big difference in role distribution. Then we outlined the main
comparison part of this study. We have shown the progress in disastermanagement laws and systems in two countries, which in most cases cameout as an outcome measures for big disasters. Section 3.3 showed thedisaster management strength and capacity of two countries, which reflects
on the normal disaster mitigation activities. Section 3.4 showed therecurring earthquakes in Bangladesh and Japan, the probable vulnerable
region, and section 3.5 discussed the preparedness and mitigation measures
for them. Section 3.6 outlined the budget of disaster management in two
countries. Finally, in section 3.7, we used Google Earth for some fixed point

630

New Technologies for Urban Safety of Mega Cities in Asia

analysis and comparison. We chosen 3 important areas of the cities based on
population, building density, road networks and open spaces.
2. CITY OUTLINES
Table-1: Basic data of Dhaka and Tokyo
Dhaka (BBS, 2009)

Area
Metropolitan Area 1500 sq. km.
City Corporation Area 360 sq. km.
Population
Metropolitan Area 10.9 million
City Corporation Area 8.0 million
Growth rate 3%
Population Density
Metropolitan Area 71/ha
City Corporation Area 222/ha
Ward 23, City 0, Town 0, Village 0

Tokyo (TMG, 2009)
Area
Metropolitan Area 2187. km.
23 Special Ward Area 621 sq. km.
Population
Metropolitan Area 12.79 million
23 Special Ward Area 8.65 million
Growth rate 0.9% (as of 2008, TMG)
Population Density
Metropolitan Area 584/ha
23 Special Ward Area 139/ha
Wards 23, City 26, Town 5, Village 8

Main data of two cities is shown in Table-1. Dhaka is the capital and maincity of Bangladesh, locating in the central southeastern region of the flatdeltaic plain of the transboundary rivers Ganges, Brahamputra and Meghna.
The city is surrounded by rivers like the Buriganga in the south, Turag in thewest, Tongi canal in the north and Balu in the east. Thus Dhaka isvulnerable to flooding and for geological location; Dhaka is also prone toearthquake. Tokyo is also the capital and main city of Japan, located in themouth of 3 large rivers like Sumida, Ara and Edo. Therefore, Tokyo is also
vulnerable to flooding. However, Tokyo has the vulnerability to typhoonand earthquakes and is characterized by large amount of assets, economic
value and a highly developed network of infrastructure.
3. COMPARSION
3.1 Urban Population Trend in Dhaka and Tokyo:
Table-2: Populaiton trend and growth rate in Dhaka and Tokyo (United
Nations, 2008), (TMG, 2009)

Population trend and growth rate in both cities is shown in Table-2.
Dhaka is the fastest growing megacity in the world. It had 1.77 million

A Comparative Study of Urban Vulnerability Between Dhaka and Tokyo

631

October 2009, Incheon, Korea

population in 1974, which reached to 10 million in 2000. The growth rateduring 1975-2000 was 6.71% (United Nations, 2008). If the high growthrate continues, it will grow at 3.34% in 2000-2015 and reach 17.0 million in
2015. It is not that for high industrial development of Dhaka. However, thecity is characterized by poverty, risk of natural hazards, social vulnerability,
shortage of housing, evacuation places and sites, road networks, poor
infrastructure and insufficient urban management. Dhaka’s increasing
population can be subject to high risk in disasters.
Tokyo’s growth rate in 1975-2000 was 0.18% (TMG, 2009), whichreached to 12.89 million in 2008 at 0.9%. Since the end of Second World
War, population concentrated to Tokyo at a high rate (Kumagai and Nojima,
1999). From the 1960s, Japanese rapid economic growth and urbanization
expanded in Tokyo until 1980s. More than a quarter of a million people
flowed to Tokyo every year and buildings mushroomed everywhere(Kumagai and Nojima, 1999). So the increasing number of population
impacted on urbanization and a mixed construction process of buildings
were found. Tokyo Metropolitan Government (TMG) has designated 95%
of Tokyo ward area as special districts for fire suppression and reduction.
The objective is to retard fire and permit evacuation in wake of anearthquake rather. Though there is shortage of open space for evacuation,
149 evacuation sites have been officially designated. TMG is supporting
community with local government to reconstruct the old areas, so thatpeople can be survived in big disasters.
3.2 Outline of Disaster Management System in Bangladesh and Japan
Table-3 discussed the disaster management system in Bangladesh
and Japan. Both countries have disaster management structure with somesimilarity and dissimilarity. Bangladesh has four layer structures. The firstlayer is the national level, where there are three bodies. These bodies havethe only role of policy formulation and implementation. The second layer isthe executive layer, where districts and city corporation stands for policy
implementation. The next layer is also a smaller executive layer, which isalso responsible for policy implementation. The final layer is the smallest
administrative layer, which should have a lot of responsibilities includingplan formulation and execution in the local level. Japanese first layer is also
the national layer. This layer has the specific role to follow up the
implementation of Basic Disaster Management Plan. The second layer issimilar to Bangladesh, the executive layer, which supposes to formulate andpromote implementation of local disaster management plan. The next levelis also similar to Bangladesh and plays same role as formulate and promotelocal disaster management plan. The last layer is residents’ layer, which isthe strengthening part of the structure. In every layer, Tokyo has only one
body. But Bangladesh has more than one body. Bangladesh has only policy
and plan formulation activities. But Japan has specific designation of action
like policy formulation, implementation, following the law and resolutions.

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New Technologies for Urban Safety of Mega Cities in Asia

Table-3: Disaster Management System in Bangladesh and Japan
Bangladesh (DMB, 2009)
SystemNational Level
1National Disaster Management
Council
2Inter-Ministerial Disaster
Management Coordination Committee
3National Disaster Management
Advisory Committee
District Level
1District Disaster Management
Committee
2City Corporation Disaster
Management Committee (DMC)
Upazila Level
Upazila/Thana Disaster Management
Committee
Union Level
Union/Municipal DMC

Roles

1Formulate policy,
guidelines
2Implementation andcoordination
3Advisory roles
Formulate and implement
local disaster management
plan (DMP)

Japan (CAO, 2009)
SystemRoles
National Level
Formulation
Central Disasterand promoting
Management Council implementationof the Basic
DisasterManagement
Plan
Prefecture Level
Formulation
Prefectural Disasterand promoting
Management Council implementationof Local DMP

Formulate and implement
local DMP

Municipal Level
Municipal Disaster
Management Council

Formulate and implement
local DMP

Residents Level

Formulationand promoting
implementationof Local DMP

3.3 Progress in Disaster Management Laws and Systems:
Both countries have developed disaster management system andthey have been experiencing a lot of natural disasters every year. The
frequency and nature of destruction caused two countries to think about
disaster management guidelines, acts, plans and systems well ahead. The
following Table-4 has been made with the major disaster events of two
countries and the acts and systems developed after that disaster event. The
table has been separated into 3 time phases. In the first phase, Bangladesh
had 6 big disasters but there was no progress in disaster management acts
and systems. Japan had 5 big disaster events out of which 3 was earthquakes.
Japan enacted 8 disaster management acts and 3 plans and systems based on
the experience of those disasters. In the second phase, Bangladesh had 17
disasters with 2 earthquakes. One of the biggest floods in Bangladesh
happened during this time in 1988. Bangladesh considered flood as number
one hazard and cyclone as number two. So to manage them efficiently,
Bangladesh first time formulated the standing order on flood in 1984 andstanding order on cyclone in 1985. These were basically set code of conduct,
explained how different organs of government will act during an impending
situation. On the other hand, Japan faced 2 big disaster events, a volcanic
eruption and an earthquake during this time. The geological society of Japan
had declared a report on the possibility of anticipated Tokai earthquake andJapan had taken 4 acts and 1 plan and system on disaster management inthis period. In the third phase, Bangladesh experienced 27 disasters. Amongthem, 14 were floods, 8 cyclones, 1 tornado, 3 earthquakes and 1 landslide.
The devastating cyclone of 1991 happened during this time. Bangladesh
enacted the national building code in 1993 and standing order on disaster in
1997. Japan faced 6 disasters during this time. Among them, 2 were big
earthquakes like Hanshin-Awaji and Chuetsu earthquake. Based on theexperience of Hanshin-Awaji earthquake, Japan enacted 7 acts, 8 other acts,
and other 13 disaster management plans and systems. After every big
disaster, Japan enacted several acts, laws or policies to reduce the casualty
in the next disasters. So a lot of safeguards were applied in Japanese disaster

A Comparative Study of Urban Vulnerability Between Dhaka and Tokyo

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October 2009, Incheon, Korea

management system. However, Bangladesh had many devastating disasters,
but there were no safeguards enacted.
Table-4: Progress in Disaster Management Laws and Systems in 2 countries
Time

Bangladesh (DMB, 2009)
DisasterDisasterManagement
Management
Acts
Plans and
Systems
1950 Earthquake
1951 Tornado
1961 Tornado
1964 Tornado
1969 Tornado
1969 Tornado
Events19401960s

19701980s

19902000s

1970 Cyclone
1972 Tornado
1973 Tornado
1977 Tornado
1989 Tornado
1984 Tornado
1985 Cyclone
1986 Flood
1986 Cyclone
1987 Flood
1988 Flood
1988 Cyclone
1988 Earthquake
1989 Tornado
1989 Flood
1989 Cyclone
1989 Earthquake
1990 Flood
1990 Cyclone
1991 Flood
1991 Cyclone
1993 Flood
1994 Flood
1994 Cyclone
1995 Flood
1995 Cyclone
1996 Flood
1996 Tornado
1996 Cyclone
1997 Flood
1997 Cyclone
1997 Earthquake
1998 Flood
1999 Flood
1999 Earthquake
2000 Flood
2002 Flood
2003 Flood
2003 Earthquake
2004 Flood2007 Landslide
2007 Flood2007 Cyclone
2009 Cyclone

1984
Standing
order onflood
1985
Standing
order oncyclone

1993
Bangladesh
nationalbuilding code
1997
Standing
order ondisaster(replaced
1984Standing
order onflood and1985
Standing
order oncyclone)EventsJapan (Cabinet Office, 2007)
Disaster Management Acts
Disaster Management
Plans and Systems

1946 Nankai
earthquake
1948 Fukui
earthquake
1959
Typhoon Isewan
1961 Heavy
snowfalls
1964 Niigata
earthquake
1973 Mt.
Sakurajima
eruption
1976 Reportabout thepossibility ofTokaiearthquake
1978 Miyagi
ken-okiearthquake

1947 Disaster relief act
1949 Flood control act
1950 Building standard law
1960 Soil conservation andflood control act
1961 Disastercountermeasures basic act
1962 Act on severe disasters
1962 Act on snowfall
1966 Act on earthquake
insurance
1973 Act on volcanoes
1978 Act on large-scale
earthquakes
1980 Act on earthquake
countermeasures
1981 Amendment of building
standard law

1995 Great
HanshinAwaji
Earthquake
1999
Torrential
rains1999 JCO
Nuclearaccident
2000
Torrential
rains
2004
Chuetsu
earthquake
2005
Typhoons andtorrential
rains1995 Act on earthquake
countermeasures
1995 Act on retrofit buildings
1995 Amendment of disastercountermeasures basic act
1995 Amendment of act onlarge-scale earthquakes
1996 Act on rights and profits
of the victims
1997 Act on disaster resilience
1998 Act on livelihood
recovery1999 Act on nuclear disasters
2000 Act on sediment disaster2002 Act on Tonankai andNankai earthquake
2003 Urban river inundationact
2004 Act on trench type
earthquake
2005 Amendment of retrofit ofbuildings
2005 Amendment of flood act
2005 Amendment of sedimentdisaster

1961 Designation ofdisaster reduction day
1962 Establishment ofcentral disastermanagement council
1963 Basic disastermanagement plan

1979 Tokai earthquake
countermeasures basic
plan

1995 Amendment of basic
disaster plan
1995 Designation ofvolunteer day
2001 Establishment of
cabinet office
2003 Policy framework for
Tokai earthquake
2003 Policy framework for
Tonankai and Nankai
earthquake
2004 Tonankai and Nankai
earthquake basic plan2005 Tokai earthquake
strategy
2005 Tonankai and Nankai
earthquake strategy
2005 Policy framework forTokyo inland earthquakes
2006 Policy framework fortrench-type earthquakes
2006 Countermeasures
basic plan for trench-type
earthquakes
2006 Tokyo inland
earthquake strategy
2006 Basic framework fornationwide movement fordisaster reduction

3.4 Possible recurring earthquake in Bangladesh and Japan:
Figure-1 shows the recurring and anticipated earthquakes in two
countries. Bangladesh anticipates 1885 Bengal and 1897 Great Indian
Earthquake for recurrence. Roger Bilham and Philip England (2001) opinedthat the great Indian earthquake with maximum M ≥8 may constitute asignificant seismic threat to nearby densely populated regions of Bangladesh
and to the very large city of Dhaka. Khan’s (2005) investigation suggested
the return period of Bengal earthquake by 2015 having return periodcharacter of 130 years. On the other hand, Japan anticipates 5 earthquakes
like Tokai, Tonankai, Nankai, Trench type and Tokyo Inland earthquakes.
Among them, 4 may directly affect Tokyo.

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New Technologies for Urban Safety of Mega Cities in Asia

N

N





Figure-1: The Great Indian Earthquake 1897’s recurring area (Bilham andEngland, 2001). Source region where large-scale earthquakes are
anticipated in Japan (TMG, 2008)
3.5 Preparedness for recurring earthquakes in Bangladesh and Japan:
In the recent past, Bangladesh did not have any big earthquake. Thus,
Bangladesh is generally complacent about the earthquake risk. Bangladesh
has no notable program for earthquake preparedness, but has some primaryawareness program and Disaster Preparedness Plan formulation activities
with local government. The Comprehensive Disaster Management Program(CDMP) unit of Ministry of Food and Disaster Management is
implementing programs like seismic risk assessment, awareness and training.
Japan has estimated human causality and economic loss in anticipatedearthquakes. Based on that, Japan is promoting program with local
government and community to reduce the loss and casualty. Table-5 showed
the preparedness for recurring earthquake in Japan.
Table-5: Preparedness for recurring earthquakes in Japan (CAO, 2007)
Estimation

Death Toll
House Destroy (increase the ratio of retrofitted
houses 75% [2003] to 90% [2015]
Economic Loss (billion yen)

Tokai Earthquake

9200 -> reduce to 4500
260000Tonanki and Nankai
Earthquake
17800 -> reduce to 9100
36000037 trillion yen -> reduce 19 57 trillion yen -> reduce totrillion yen
31 trillion yen
Every municipality at risk expected to develop hazard maps by 2015

3.6 Disaster management related budget in Bangladesh and Japan:
Bangladesh has no specific budget for disaster management. In
practice, Bangladesh allocates emergency disaster response money fromdevelopment budget. But development agencies in Bangladesh have theirown budget for disaster preparedness and mitigation. Japan has specificbudget for disaster management. As per the Disaster Countermeasures Basic
Act 1961, both central and local government in Japan must have thebudgetary arrangement for disaster management. The average budget fordisaster management in Japan from 1995 to 2004 was approximately 4.5
trillion yen, which has the following breakdown (CAO, 2007) in Figure-2.

A Comparative Study of Urban Vulnerability Between Dhaka and Tokyo

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October 2009, Incheon, Korea

Japan's Disaster Management Budget 1995-2004: % of Total Budget
48.7

26.4

23.6

1.3
Scientific Technology Disaster Prevention andResearch
Preparedness

National Land
Conservation

Disaster Recovery andRehabilitation

Figure-2: Disaster Management Budget Trend in Japan (CAO, 2007)
3.7 Fixed point analysis and comparison using Google Earth:
In this section, Figure-3, we used Google Earth to choose 1 km² areaof 3 important parts of Dhaka city for the comparative analysis with Tokyo.
The selected parts represent other parts of Dhaka. They are Bakshi Bazar,
oldest business and residential part; Motijheel, main commercial part andBaridhara, the newer residential and diplomatic part. We considered roadshapes, building density and open spaces. Areas in Tokyo we chosen werebased on same criteria. They are Higashi Ikebukoro, old residential part,
Asakusa, commercial place and Higashi Ginza, the biggest business place.
D-1: Bakshi Bazar

D-2: Motijheel

D-3: Baridhara

T-1: Hi Ikebukoro, Toshima

T-2: Asakusa, Minato

T-3: Higashi Ginza, Chuo

Figure-3: Fix point analysis of Dhaka and Tokyo using Google Earth
D-1: Bakshi Bazar in Dhaka: This area is characterized by disorder of
construction of buildings and road networks. Roads are not straight andparallel. Some roads are dead-end. Buildings are congested and blocks are
disorganized. Buildings are not high and have typical construction. A goodnumber of wooden houses are there. No space between buildings and roads

636

New Technologies for Urban Safety of Mega Cities in Asia

are narrow. Some scattered open spaces are seen, which seems insufficientfor the area. T-1: Higashi Ikebukoro in Tokyo: This area is alsocharacterized by disorder of construction of buildings and road networks.
This area is densely crowded. Blocks are disorganized. Some roads areparallel and buildings are constructed on the road. Some dead end roads arealso seen. Buildings are not much high and a good number of wooden
houses are there. Space between houses is very narrow. Not much open
space is visible. D-2: Motijheel in Dhaka: This area has disorderedcharacteristics. The residential and commercial buildings do not haveenough space between them. Few roads are straight and parallel. Some
small roads have dead end. Houses are very dense looked. Residentialbuildings congested and blocks are disorganized. A lot of wooden houses
are there. Some scattered open spaces are seen. It also looks insufficient forthis area. T-2: Asakusa in Tokyo: This area is comparatively organized.
Roads are straight and parallel. Buildings are constructed in blocks. A lot ofbuildings are constructed in each block. Blocks are rectangular. Both smalland high buildings are visible. The space between buildings is narrow.
Wooden houses are also seen. Some scattered open spaces are there. Roadnetworks looked very organized. D-3: Baridhara in Dhaka: This part looks
organized than the other discussed two parts of Dhaka. Roads are parallel
but buildings are congested in blocks. Small and narrow space between
buildings is seen. The area has Lake in one side and congested area in other.
Several open spaces are seen. But they seem insufficient for the area. T-3:
Higashi Ginza in Tokyo: This area is organized. Roads are parallel.
Buildings are in blocks. Many high commercial buildings are seen. Not
much empty space between buildings is seen. Several open spaces are seen.
4. ANALYZE AND DISCUSSION
Table-6: Vulnerability comparison between Dhaka and Tokyo
D-1

Dhaka
D-2

D-3

T-1

Tokyo
T-2

T-3

disorganizeddisorganizedorganized

disorganizedorganizedorganized

disorganizedbuilding density
Building
100
density/haSpacenobetweenbuilding
Open spaces
Type
empty space,playgroundNumber/skm
2

disorganizedorganized

disorganizedrectangularorganized

70

48

108

66

40

no

narrow

no

small

small

empty space,playground2

playground,empty space5

small parks

small parks,
playground4

parks,
playground
5

Road Shape
Shape
blocks2

As per the analysis, D-1 is most vulnerable to disaster like earthquake. Mostof the buildings are old and had typical construction. They may not take theextra load of earthquake. If a building collapse, it has the possibility to fallon the nearby one. A good number of burnable wooden houses are there.
They may cause big fire. Narrow road networks may obstacle for rescue andfire fighting work. There is a scarcity of open space too. So rescue, fire
prevention and evacuation will be difficult here. The D-2 can be explained
as same as D-1. Two big stadiums are nearby, which can be used for

A Comparative Study of Urban Vulnerability Between Dhaka and Tokyo

637

October 2009, Incheon, Korea

evacuation. The D-3 is comparatively in better position. But if the buildings
collapsed, the question of open space will be important for this area. For
Tokyo, T-1 area can be explained same as D-1. But this area is changing
with the support of the local government. So the open space is increasing,buildings are restructuring to withstand with earthquake risks. The T-2 isalso improving like increasing open space and changing the road shapes.
The T-3 area is in the best position among the six points. It has wide road
networks, several parks and playgrounds as open space. Comparing withother discussed data and criteria like population, disaster management laws
and systems, big earthquake in the past, possible recurrence and disastermanagement budget, Dhaka is more vulnerable to urban disaster than Tokyo.
5. CONCLUSION
Based on the main data and fixed point analysis, Dhaka’s urban
vulnerability is evident. Though Tokyo is still vulnerable, but Tokyo
promotes mitigation activities in an organized manner. So the vulnerability
range is changing as per the estimated preparedness of the TMG. Thus cities
like Dhaka can follow Tokyo’s practice to reduce their urban vulnerability.
REFERENCES
Al-Hussaini, T.M., 2003. Critical Elements for Earthquake Disaster in
Dhaka City, paper presented at USMCA 2003 Symposium on New
Technology for Urban Safety of Mega Cities in Asia, Tokyo, Japan.
Bilham, R., and England, P., 2001. Plateau 'pop-up' in the great 1897 Assamearthquake, Nature, 410, 806-809.
Cabinet Office (CAO), Government of Japan, 2007. Disaster Managementin Japan.
Khan, A.A., and Hossain, M.S., 2005. Recurrence of 1885 Bengal
Earthquake and hazard vulnerability status of Dhaka metropolitan
city, Bangladesh. Oriental Geographer, v.49(2), p. 205-216.
Kumagai, Yoshio, and Nojima, Yoshiteru, 1999. Urbanization and Disaster
Mitigation in Tokyo, Crucibles of Hazard: Mega-cities andDisasters in Transition, Tokyo.
Sarkar, M.M.H., and Ferdousi, S., 2004. Assessment for role of GIS BasedNatural Disaster Database in Environmental Management andPlanning activity in Bangladesh, Environmental Informatics
Archives, Volume 2, 855-836
United Nations, 1999. World Urbanization Prospects: The 1999 Revision.
New York: United Nations.
United Nations, 2008. World Urbanization Prospects: The 2007 Revision.
New York: United Nations.
Bangladesh Bureau of Statistics (BBS), 2009. At http://www.bbs.gov.bd/
checked on July 9, 2009.
Disaster Management Bureau (DMB), 2009. At http://www.dmb.gov.bd/
checked on June 26, 2009.
Tokyo Metropolitan Government (TMG), 2009. At
http://www.metro.tokyo.jp/ENGLISH/ Checked on June 20. 2009.
638

New Technologies for Urban Safety of Mega Cities in Asia

A STUDY ON THE EFFICIENT EARLYWARNING METHOD USING COMPLEXEVENT PROCESSING (CEP) TECHNIQUES
Kim, Hyung Woo
KT R&D Laboratory, Republic of Korea
hyungwoo@kt.com,
Kim, Goo Soo
KT R&D Laboratory, Republic of Korea
goosoo@kt.com
Chang, Sung Bong
KT R&D Laboratory, Republic of Korea
sbchang@kt.com

ABSTRACTIn recent years, there is a remarkable progress in ICTs (Information
and Communication Technologies), and then many attempts to apply ICTs
to other industries are being made. In the field of disaster managements,
ICTs such as RFID (Radio Frequency IDentification) and USN (Ubiquitous
Sensor Network) are used to provide safe environments. Actually, various
types of early warning systems using USN are now being widely used tomonitor natural disasters such as floods, landslides and earthquakes, andalso to detect human-caused disasters such as fires, explosions andcollapses. These early warning systems issue alarms rapidly when a disasteris detected or an event exceeds prescribed threshold value, and furthermoredeliver alarm messages to disaster managers and citizens. In general, thesesystems consist of a number of various sensors measuring real-time stream
data, which requires an efficient and rapid data processing technique. In
this paper, an event-driven architecture (EDA) is presented to collect event
effectively and to provide an alert rapidly. Additionally, a complex event
processing (CEP) technique is introduced to process complex data fromvarious sensors and to provide prompt and reasonable decision supports
when many disasters happen simultaneously. A basic concept of CEP
technique is presented and the advantages of the technique in disastermanagement are discussed briefly. An example of flood early alarm systemusing CEP is presented. It is found that the CEP based on the EDA will
provide an efficient early warning method when disaster happens.

1. INTRODUCTION
With a rapid development of ICT (Information and Communication
Technology), USN (Ubiquitous Sensor Network) is widely applied todisaster monitoring systems. Natural disasters such as floods, landslides,639

October 2009, Incheon, Korea

and earthquakes, and human-caused disasters such as fire, explosion, andcollapse are monitored by these sensor networks. The disaster monitoring
systems should collect accurate information from sensors, and provide rapid
response for emergency management. In addition, it is necessary for thesystem to share information relevant to disaster with various organizations
such as police, hospital, a fire brigade and military. Current disastermonitoring systems, however, use their own systems purchased fromdifferent vendors. The vendors follow their own proprietary and closed
communication protocols, and thus it costs great money for enabling acommunication channel between applications from two different vendors.
Therefore, a new architecture is required for seamless integration between
various applications in disaster management. There is also a need for
implementation of an open standard for information interoperability.
Additionally, the current disaster monitoring system has a data bus that isclosed and proprietary. This makes it very difficult to plug in third party
applications. Moreover, for the communication between disaster authorities,
the data format is proprietary. The feature of existing architecture is that thedata bus carries only the data. Each application needs to come down to thedata level, process the data and act upon the data. The architecture is largely
data oriented rather than event oriented. Events make more sense than raw
data on systems with a high demand for situational awareness and real time
monitoring (Medhekar, 2008).
To solve these problems, an event-oriented architecture is introduced.
The architecture is basically based on the web-service eventing technology
which makes it possible to communicate with heterogeneous systems. In
addition, a complex event processing method is introduced for real-time
disaster monitoring.

2. DISASTER MANAGEMENT
2.1

Basic requirements

Generally, it is recommended that the disaster monitoring systemshould be designed to respond rapidly and implemented by reliable, stableand proven technology not to give a false alarm. It is also operated in realtime manner and designed to issue alert without delay. In addition to theserequirements, disaster monitoring systems should have interoperability.
Interoperability has several levels: organization, application, informationand technical level operability. Organizational interoperability is ensured bya standard inter organization protocol, which expresses the way in whichorganizations have to communicate and share data. Applicationinteroperability can be achieved by enforcing an inter application protocol.
Information interoperability is ensured by complying with a standard
information model. Finally, technical interoperability is achieved by using
standard device level protocols. (Medhekar, 2008).
Early warning system for disaster management is especiallycharacterized by distribution of unit systems comprising of sensor networks
and distribution spread over a large geographical area. Disaster information

640

New Technologies for Urban Safety of Mega Cities in Asia

gathered by unit systems should be shared between organizations. Therefore,
coordination between these systems is required and achieved byinteroperability.

3. EDA (Event-Driven Architecture)
3.1

Introduction

3.1.1

What is event?
An event is defined as something notable that happens inside oroutside a system. Its occurrence may denote a problem, an impending
problem, an opportunity, a threshold, or a deviation. Events are transmitted
as event messages, each of which has an event header and an event body.
Event header normally contains meta-data to be used for quick reference,such as event specification ID, event type, event name, event timestamp,
event occurrence number, and event creator. Event body contains the fulland detailed description of what has actually happened (Medhekar, 2008).
3.1.2

Event processing methods
Recently, various technologies that support event-driven architecture
have been applied to disaster monitoring. Event processing methods are
categorized as (1) simple event processing; (2) stream event processing and(3) complex event processing. In simple event processing, a notable event
happens, initiating downstream actions. It is commonly used to drive thereal-time flow of work, removing lag time and cost from the system. In
stream event processing, both ordinary and notable events happen. Ordinary
events are first checked for notability and then streamed to the information
subscribers. Such kind of event processing is normally used to drive thereal-time flow of information in and around the system. Complex event
processing (CEP) deals with evaluating a confluence of events and thentaking action. CEP is commonly used to detect and respond to businessanomalies, threats, and opportunities (Michelson, 2006).
3.2

SOA (Service-Oriented Architecture)

3.2.1

What is SOA?
SOA is defined as an architecture that is made up of components andinterconnections that stress interoperability and location transparency. SOA
provides an approach for building systems that deliver application
functionality as services to the end user applications or other services. SOA
contains components, services and processes. A service is a grouping ofcomponents and these services are joined together by the processes to forma business process. This concept basically has three components: service
provider, service broker, service requester. Three operations are publish,
find and bind (Joshi, 2005).
SOA facilitates integration of heterogeneous systems and increases thereuse possibilities of programs. Rather than building or possessing every
program component, developers are able to assemble the best services
available on the internet according to their needs. In addition, real openness

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October 2009, Incheon, Korea

of systems will be achieved with SOA since the components are not limited
to units of functionality or platforms developed by certain vendors. These
components and operations bound together with SOA collaborations, which
is based on publish-find-bind paradigm. According to this pattern, a service
provider gives a description of the service it wants to publish to the service
registry. This description includes a description of the interface at which theservice instance is available. A service consumer performs a dynamic
service location by querying the service registry for a service that matches
its criteria. If the queried service exists, the registry provides the consumer
with the interface contract and the endpoint address for the service (Joshi,2005).
3.2.2

Web service
A web service is defined as an interface that describes a collection ofoperations that are network accessible through standardized XML
messaging. It covers all the details necessary to interact with the service,including message format, transport protocols and location. The interface
hides the implementation details of the service, allowing it to be used
independently of the hardware or software platform on which it is
implemented and also independently of the programming language in which
it is written. This allows and encourages web services-based applications to
be loosely coupled. The web service architecture is based upon publish-findbind paradigm defined by SOA pattern (Joshi, 2005).
3.3

EDA (Event-Driven Architecture)

3.3.1

What is EDA?
In an event-driven architecture, a notable thing happens inside oroutside one’s business, which disseminates immediately to all interested
parties (human or system components). The interested parties evaluate theevent, and optionally take action. The event-driven action may include theinvocation of a service, the triggering of a business process, and/or further
information publication (Brenda, 2006).
An event-driven architecture is extremely loosely coupled, and highly
distributed. The source knows only how and when to create the event andhas no knowledge about the event’s subsequent processing, or the interested
parties. Hence, it is difficult to trace an event through a dynamic multipath
event network. Event-driven architectures are best used for asynchronous
flows of information (Medhekar, 2008).
3.3.2

EDA vs. SOA
SOA and EDA have many things in common, because they both areways of combining multiple software modules into large distributed
applications. However, they differ in the way they organize the relationships
among the modules, and this makes them appropriate for different purposes.
SOA uses directed, generally bidirectional, request/response communication,
whereas EDA uses unidirectional messaging to communicate among two or
more, largely independent peer procedures (Schulte, 2003).

642

New Technologies for Urban Safety of Mega Cities in Asia

EDA is more efficient than SOA if there are multiple destinations forthe same data, because the source sends the event only once, whereas an
SOA client would have to make successive calls to achieve the same wide
distribution. Comparisons between SOA and EDA are shown in Table 1.
Table 1: Comparisons between SOA and EDA.
SOA
EDA
Has one-to-one connections
Supports
many-tomany
connections
Has flow routing that is directed Has a flow of control that isby the client (sender)
determined by the recipient basedon the message itself
Employs a linear path of execution Supports
dynamic,
parallel,through a hierarchy of modules
asynchronous flows through a
network of modules
Is closed to new, unforeseen input Can react to new, external input
once a flow is started
that may arrive at unpredictable
times
3.3.3

Communication model
In an early-warning system, an efficient communication pattern isnecessary between the data sources and the alerting services. Pull data
model doesn’t support proactive dispatching of data as in the case requiredin emergency warning situations, where data must be dispatched whencertain event occurs. On the other hand, a push model overcomes thesynchronous request/response pattern between the client and service byallowing asynchronous data dissemination. Push model corresponds to an
event-based system, with which the components communicate over the
asynchronous exchange of events (Joshi, 2005).

4. CEP (Complex Event Processing)
4.1

Introduction

4.1.1

What is CEP?
CEP is a processing methodology which can be used to detect patternsof events and infer new meanings. Key considerations for applications
contains: (1) high throughput applications that process large volumes ofmessages (between 1,000 to 100k messages per second); (2) low latency
applications that react in real-time to conditions that occur (from a few
milliseconds to a few seconds); and (3) complex computation applications
that detect patterns among events, filter events, aggregate time or length
windows of events, join event streams, trigger based on absence of events,
etc (EsperTech, 2009).
CEP is used for detection and processing of a confluence of events.
CEP is extremely useful in applications which need to process and analyze
large numbers of real-time events. CEP thus has a huge application in the

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October 2009, Incheon, Korea

highly dynamic systems, with frequently flowing, high volumes of real time
data. Disaster monitoring is one such area (Medhekar, 2008).
4.1.2

Advantages over conventional approach
It takes time to store information in a database. Even if an in memory
database is used, latency due to disk I/O cannot be avoided. Event
processing is based on the push model, when as soon as events are pushed
into the channel, they get processed. Data, however, needs to be processedby pulling it out of the database – making it less real time (Medhekar, 2008).
CEP allows applications to store queries and run the data through,instead of storing the data and running queries against stored data. Response
from CEP is real-time when conditions occur that match queries. The
execution model is thus continuous rather than only when a query is
submitted (EsperTech, 2009).
4.2

Design patterns

There are basic CEP design patterns which may be thought of as
building blocks that can be combined to create complete applications. They
are filtering, in-memory caching, aggregation, database lookups, database
writes, correlation and event pattern matching.

Figure 1: Complex Event Processing Functions [source: BEA]
Filtering involves filtering of events based on the event attributes andin-memory caching involves caching and accessing of streaming events anddatabase data in the memory. Aggregation over windows involves
computation of statistical metrics over various kinds of moving windows. It
does not merely keep events in memory, but uses the stored values tocompute various statistics. It has different types based on the characteristics
such as kind of aggregators (sums, counts, min, max, standard deviation)and kinds of windows (time-based, count-based, moving). Correlation
facilitates joining of multiple event streams. Most advanced applications
must look at and correlate events across multiple streams. Event pattern

644

New Technologies for Urban Safety of Mega Cities in Asiamatching facilitates complex, time-based matching of events across multiple
event streams. It can be used to detect a number of relationships among
events. Typical design patterns are presented in Figure 1 (Medhekar, 2008).

5. FLOOD EARLY WARNING SYSTEM
5.1

Rule based event processing

5.1.1

Flood forecasting
In this paper, flood early warning system for urban storm water ispresented using CEP. Flood warning process has four stages such asdetection, forecasting, warning and response stages. In the detection stage,real-time data is monitored and a flood event is generated. Forecasting stage
uses the data to predict water level as well as the time of occurrence of flood
event. Warning stage utilizes the information derived from the detection andforecasting stages and issue a warning to disaster authorities. Finally,
response to the flood warning includes flood damage control measures suchas flood control reservoir and evacuation of people (Joshi, 2005).
Up to now, a number of flood forecasting models are developedaround the world, and they are mainly on the basis of hydrologic
observations such as gauged rainfall and flows. Among the flood forecasting
systems, there is a basic system that is typically based on exceedance of
certain threshold value of hydrological parameter. In this case, a warning is
triggered when one or more parameters are exceeded. This enables technicalas well as non-technical decision makers to better understand the flood(Joshi, 2005).
5.1.2

Rules for flood forecasting
A rule based approach can be used to forecast flood and dispatch alert
notifications. It is based on threshold value exceedance and can be applied
to examples as follows:– Rule 1: if river gauge level exceeds threshold value of 5 m incertain reach of the river, send alert message;– Rule 2: if the river rise velocity exceeds threshold value of 0.5 m
per 10 minutes, send alert message;– Rule 3: if the moving average of river gauge levels for 30 minutes
interval exceeds 5 m, send alert message;– Rule 4: if sum of river gauge levels installed at the river basin
exceeds threshold value of 20 m, send alert message;– Rule 5: if cumulated rainfall depth in certain area exceeds 100
mm in 24 hours, send alert message.
Moreover, another rule is set by combining these rules. The thresholdvalue for river level varies at different location of observations along theriver reach. River gauge level is also influenced by rainfall depth. Therefore
the minimum and maximum threshold values of the observation parametersuch as river gauge level are to be predefined (Joshi, 2005).

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October 2009, Incheon, Korea

5.2

Implementation

5.2.1

Architecture
When events from multiple sources are fed into the engine, CEP
analyzes them based on current rules and upon detection, alerts are sent out
as messages and actions are triggered. In our flood early warning system,
Esper is used as a CEP engine because it is an open source and easy to use(EsperTech 2009). Figure 2 shows the architecture of flood early warning
system which has been implemented.

Figure 2: Architecture of flood early warning system
Data gathered by rainfall gauge and river gauge are sent to gateway
via web service protocol. The gateway communicates with sensor nodes bymeans of communication module, and analyzes and answers the packets
sent from sensor nodes. The detected data and detecting time from sensor
nodes are fed into CEP engine where data are processed according to thepredefined rules and alert messages are generated. Raw events are generated
as standard formats and published and subscription data is registered so that
subscriber can select them. The subscription time and data type can be also
selected. Then, the subscription data is delivered to subscriber via event
sinks such as SMS (Short Message Service) and VMS (Variable Message
Sign).
5.2.2

Main features
We have developed flood early warning system using EDA-CEP.
Since the system is based on the web service architecture, interoperability is
assured, which means that information sharing between organizations is
possible. Event sources are uploaded to a platform which can publish,
subscribe and process them. End users then access the platform to search
and fetch valuable information and value-added applications. Figure 3
shows a flood monitoring screen displaying real-time rainfall depth, waterlevel and CCTV images. Assets such as monitoring stations can be easily
added to this screen dashboard by mouse drag and drop. The rules for flood
forecasting are easily input through this screen, and they are transformed toan EPL (Event Processing Language) for complex event processing. Events

646

New Technologies for Urban Safety of Mega Cities in Asia

that exceed predefined threshold value are dispatched to the subscriber
without delay via SMS and VMS.

Figure 3: Dashboard of flood early warning system

6. CONCLUSIONS
We have described architectures for disaster management and introduced
event processing methods. It is expected that the EDA is a suitablearchitecture for disaster management which requires organization andinformation interoperability. It is also expected that the CEP would be more
relevant than a traditional data processing system in the field of disastermanagement. Thus, CEP based on EDA will be widely applied to flood
early warning system. The system implemented in this paper is now being
tested at the small urban river basin, and will be verified in the future.

REFERENCES
BEA, Event Driven SOA.
Brenda M. Michelson, 2006. Event-Driven Architecture Overview. Patricia
Seybold Group.
EsperTech. 2009. Esper Reference Documentation.
Joshi, A. 2005. Active Web Alert Service for Rule Based Alerting in Sensor
Web – An Event Based Approach. Thesis for the degree in Master of
Science in Geoinformatics.
Medhekar, A. 2008. Event-driven architecture for Indian Power Systems.
Dual Degree Project Report (Stage III), Department of Computer Scienceand Engineering, Indian Institute of Technology, Bombay, Mumbai.
Schulte, R. 2003. Event-Driven Applications: Definitions and Taxonomy.
Gartner, Research Note.
Schulte, R. and Natis, Y. 2003. Event-Driven Architecture Complements

A study on the efficient early-warning method using complex event processing (CEP) techniques647

October 2009, Incheon, Korea

SOA. Gartner, Research Note.
US Army Corps of Engineers. 1993. Application of Rainfall-Runoff
Simulation for Flood Forecasting.

648

New Technologies for Urban Safety of Mega Cities in Asia

A SURVEY ON RESIDENTS’ RESPONSETO EARTHQUAKE EARLY WARNING
AT THE 2008 IWATE-MIYAGI INLAND
EARTHQUAKE IN JAPANMiho OHARA
Interfaculty Initiative in Information Studies,
The University of Tokyo, Japanohara@iis.u-tokyo.ac.jp
Yasuhito JIBIKIInterfaculty Initiative in Information Studies,
The University of Tokyo, Japan
Naoya SEKIYA
Toyo University, Japan
Tetustaro SUMIInterfaculty Initiative in Information Studies,
The University of Tokyo, Japan
Kimiro MEGURO
ICUS, Institute of Industrial Science, The University of Tokyo, Japanmeguro@iis.u-tokyo.ac.jp
Atsushi TANAKAInterfaculty Initiative in Information Studies,
The University of Tokyo, Japan
ABSTRACTJapan Meteorological Agency (JMA) started the service of earthquake
early warning (EEW) to the public since October 1, 2007. When the 2008
Iwate-Miyagi Inland Earthquake occurred on July 14, 2008, EEW
information was provided to the regions whose intensities of shaking were
expected to be more than JMA 4. The warning was widely broadcasted by
TV, radio, mobile phones and loudspeakers. Unfortunately, the warning
could not be transmitted before the arrival of strong tremors in areas thatwere close to the focus of the earthquake. However, in several cities outside
those areas, the leading time between the warning and the arrival of strong
tremors was around 10-15 seconds and residents could do some response to
the warning. It was the first earthquake since October, 2007 that EEW
could be successfully broadcasted before the arrival of strong tremors.
In Shonai Town, Yamagata Prefecture, EEW information was
broadcasted at the 2008 Iwate-Miyagi Inland Earthquake by loudspeakers
using J-Alert system that transmits information by satellite. In this research,
a questionnaire survey was conducted to understand residents’ response to
the warning. 800 questionnaire sheets were distributed in the town and 591
answers were obtained. Just after hearing the warning, most of the
respondents tried to get earthquake information by TV or radio. Very few
residents tried to protect their bodies or protect their children and elderfamily members. The result of the survey revealed that residents’649

October 2009, Incheon, Korea

understanding on proper response to EEW was insufficient and it isnecessary to enhance residents’ capacity to take proper action when they
got the warning.
1. INTRODUCTION
Japan Meteorological Agency (JMA) started the service ofearthquake early warning (EEW) to the public since October 1, 2007. Thisis a new system that quickly analyses seismic wave data observed byseismographs near the epicenter and provides prompt alerts before strong
tremors (S-waves) arrive. It aims at mitigating earthquake-related damage
by allowing countermeasures such as enabling people to quickly protect
themselves in various environments such as houses, offices and factories. A
warning is widely broadcasted by TV, radio, mobile phones andloudspeakers.
J-Alert is another warning system in Japan launched in February 2007.
It is a satellite based system that allows authorities to quickly broadcast
alerts to local media and to residents directly via system of loudspeakers.
Figure 1 shows the process that EEW information is transmitted by J-Alertsystem. After the nearest seismometer observed P wave, the seismic wave
data was analyzed and the focus, magnitude and intensities are estimated.
After JMA announce EEW, the Fire and Disaster Management Agency(FDMA) sent EEW to local government by satellite. In the local
governments, loudspeaker system automatically boots and starts tobroadcast EEW to the residents. The FDMA operates J-Alert system for the
purpose of protecting citizens. Alerts include not only natural disasters liketsunamis and earthquakes but also military threats such as missiles andterrorist attacks. According to the newsletter of the FDMA, 43 prefectures intotal 47 prefectures and 150 local governments in total 1781 adopted J-Alertsystem as of January 9, 2009. These numbers will increase in the future as
the FDMA is strongly promoting adoption of J-Alert system.
Satellite
Transmit observed data

P-waveS-waveLoudspeaker

S-waveSeismograph

Focus
When P-wave was observed

Focus
When J-Alert system booted
loudspeakers in local areas

Figure 1: Process that EEW information is transmitted by J-Alert system
In Japan, the Iwate-Miyagi Inland Earthquake occurred in the south of
the inland of Iwate Prefecture at 8:43 JST on Saturday morning, June 14,
2008. The JMA magnitude was estimated at Mj 7.2 and maximum JMA
intensity was measured as “6 Lower” on the JMA intensity scale. According
to the report by the FDMA, 17 people died, 426 people injured and 30

650

New Technologies for Urban Safety of Mega Cities in Asia

houses were totally damaged. Just after the earthquake, EEW was provided
to the regions whose intensities of shaking were expected to be more than
JMA 4. Figure 2 is a map published by the JMA showing the epicenter ofthe earthquake and the lead time before the arrival of strong tremors. Yellow
parts in figure 2 show the areas that EEW is broadcasted. Unfortunately, thewarning could not be provided before strong tremors in the areas that wereclose to the focus of the earthquake. However, in several cities outside thoseareas, the lead time between the warning and the arrival of strong tremors
was around 10-25 seconds and residents could do some response to thewarning. It was the first earthquake since October, 2007 that could be
successfully broadcasted before the arrival of strong tremors. The warning
was widely broadcasted by TV, radio, mobile phones. In addition, thewarning was broadcasted to residents via loudspeakers using J-Alert systemin the regions whose intensities were expected to be more than JMA 5 upper.
This was the first broadcasting of EEW using J-Alert system although theregions were limited to be 2 cities and 1 town.
Shonai town, Yamagata prefecture was one of the regions where EEW
was broadcasted by loudspeakers using J-Alert system. The location was
illustrated in figure 2. In this research, a questionnaire survey was conductedin Shonai Town in order to understand residents’ response to the warning.
Authors think that residents’ experience of receiving EEW by all thecommunication ways including loudspeakers by J-Alert system in Shonai
town was very precious for discussing better use of EEW information.

Shonai Town,
Yamagata Prefecture
epicenter

Figure 2: Epicenter and lead time between EEW and the arrival of strong
tremors at the Iwate-Miyagi Inland Earthquake

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October 2009, Incheon, Korea

2. PROCESS OF BROADCASTING OF EEW IN SHONAI TOWN
Shonai Town is a small town with 24,073 populations in 249.26
squire kilometers. Shonai Town adopted J-Alert system in April 2008. After
2 months, the Iwate-Miyagi Inland Earthquake occurred. Before April, thetown office explained the start of J-Alert system to town leaders andannounced it in the town news magazine in March.
Process of broadcasting of EEW using J-Alert system was shown in
Table 1. The table includes the process after two earthquakes: the IwateMiyagi Inland Earthquake at 8:43 JST on June 14 and another earthquake
offshore Iwate prefecture at 0:26 on July 24. At the Iwate-Miyagi Inland
Earthquake, EEW was broadcasted to the public 10 seconds after theearthquake occurrence at the focus. After 1 seconds of this, J-Alert system
in Shonai Town office received an alert of shaking with intensity 4 from the
FDMA by satellite. However, J-Alert system didn’t boot because thecriterion of booting the system was set to be intensity 5 lower. At 28
seconds after the earthquake occurrence, expected intensity increased tointensity 5 lower and J-Alert booted. Finally, loudspeakers in Shonai Town
started to announce EEW at 41 seconds after the earthquake occurrence, as
preparation of broadcasting currently required 12 seconds.
Figure 2 shows the timing of broadcasting EEW at the Iwate-Miyagi
Inland Earthquake. The periods of chime sound (8 seconds) and the warning
saying “This is Big Earthquake, this is Big Earthquake” (6 seconds) were
illustrated on the seismic waves recorded by the nearest seismograph of
Kyoshin-Net (seismograph network by the National Research Institute for
Earth Science and Disaster Prevension (NIED) ). According to the Figure1,
S- wave arrived at Shonai Town between the boot of J-Alert System and thestart of EEW broadcasting by loudspeakers. Warning by J-Alert failed tobroadcast before the arrival of S-wave although EEW was successfully
broadcasted to the public on TV and Radios.
Based on the lessons from the Iwate-Miyagi Inland Earthquake inJune, the criterion of booting J-Alert system was lowered to intensity 4 thatis same as EEW broadcasting for the public. At the earthquake on July 24,
J-Alert System in Shonai Town office received an alert from the FDMA bysatellite 10 seconds after the earthquake occurrence at the focus.
Loudspeakers in Shonai Town successfully started to announce EEW before
the arrival of S-Wave at 23 seconds after the earthquake occurrence. This
was the first broadcasting of EEW by J-Alert before strong tremor since JAlert launched in Japan. In this case, the change of criterion forbroadcasting to intensity 4 led to early information propagation. In order toincrease possibility of successful warnings before strong tremors in the
future, improvement of both EEW system and J-Alert system are necessary.
Especially, cut down of the boot-time, increase of number of local
governments that adopted J-Alert system are essential.

652

New Technologies for Urban Safety of Mega Cities in Asia

Table 1: Process of broadcasting of EEW at two earthquakes

Time
Earthquake occurrence at the focus
EEW broadcasting to the puelic
Arrival of P wave at Shonai Town
Alert of intensity 4 from FDMA
Alert of intensity 5 lower from FDMA
Boot of J-Alert system
Start of broadcasting EEW by loudspeakers

June 14
Elapsed time(s)Elapsedafter P-wave
time(s)in Shonai

8:43:45
8:43:55
8:44:04
8:43:56
8:44:13
8:44:14
8:44:26

10
19
11
28
29
41

0
9
10
22

Time

July 24
Elapsed time(s)Elapsedafter P-wave
time(s)in Shonai

0:26:35
0:26:56
0:26:51
0:26:45

21
16
10

0:26:48
0:26:58

13
23

5
0

7

6/14 8:43 -9s: EEW broadcasting on TV
10s: Boot of J-Alert
100.17gal

22s: Start of broadcasting EEW by loudspeakers
44s: End of broadcastingＮＳ：Chime sound：Warning words-100.17gal

Figure 3: Timing of broadcasting EEW at the earthquake on June 14
7/24 0:26 -10s: Boot of J-Alert
9.34gal5s: EEW broadcasting on TV
7s: Start of broadcasting EEW by loudspeakers
29s: End of broadcastingＮＳ-9.34gal：Chime sound：Warning words

Figure 4: Timing of broadcasting EEW at the earthquake on July 24

3. OUTLINE OF QUESTIONNAIRE SURVEY
In order to understand residents’ responses to the warning, aquestionnaire survey for residents was conducted in Shonai Town thanks tothe cooperation with Shonai Town office. 800 questionnaire sheets were
distributed in the town and 591 answers were obtained in October 2008.
3.1 Characteristics of Respondents
Among 591 respondents, 57.2% of the respondents are male and42.8% are female. Ratio of respondents’ age is shown in figure 5. Half ofthe respondents are more than 60 years old. 79.9%, 16.3% and 1.8% of the
respondents live in two-story single-family timber houses, one-story singleA Survey on Residents’ Response to Earthquake Early Warning at the 2008 Iwate-Miyagi Inland Earthquake in Japan653

October 2009, Incheon, Korea

family timber houses and timber apartments. 13.7% of the respondents haveelder family member who cannot walk by themselves. 7.8% of the
respondents have infants and 23.6% have children kindergartens orelementary school.
Figure 6 shows the respondents who experienced past disasters suchas the 1964 Niigata Earthquake, the 1983 Nihonkai-Chubu Earthquake.
Regarding respondents’ anxieties for disasters, anxiety for earthquakes is
the highest among heavy rains, floods, landslides and strong winds. About
70% of the respondents have strong anxiety and 25% have little anxiety forearthquakes.
1. 20s
1.3%

2. 30s
5.0%

6. morethan 70s
24.0%

3. 40s
13.2%

5. 60s
25.8%

4.50s
30.8%

Figure 5: Ratio of respondents’ age
1. The 1964 Niigata Earthquake

86.2%

2. The 1967 Uestu Flood

24.0%

3. The 1971 Flood

41.5%

4. The 1972 Yamaga-Chubu Earthquake

29.4%

5. The 1983 Nihonkai-Chubu Earthquake

56.7%

6. Others

1.4%
0.0%

50.0%

100.0%

Figure 6: Ratio of respondents who experienced past disasters

3.2 Respondents’ Knowledge on EEW
Next, respondents’ knowledge on EEW and its broadcasting ways
were asked. Figure 7 shows the ratio of their knowledge on EEW before
both earthquakes. 48.7% knew both the name of EEW and the meaning that
it forecast a strong tremor just before its arrival. However, 33.4% knew only
the name of EEW and 17.9% knew neither its name nor its meaning. Whenthe Iwate-Miyagi Inland Earthquake occurred in June 2008, almost 7
months had passed since its service for the public started. The low
percentage of the respondents who fully understood the meaning of EEW
before the earthquakes suggests the necessity for increasing peoples’
knowledge on EEW.
Figure 8 shows the ratio of their knowledge on broadcasting ways of
EEW before both earthquakes. 27.3% knew the broadcasting by both TV
and loudspeakers. 43.1% knew the broadcasting only by TV, and 12.9%

654

New Technologies for Urban Safety of Mega Cities in Asiaknew only by loudspeakers. The ratio of the respondents who knew thebroadcasting of EEW by loudspeakers was less than half. The reason for thismight be J-Alert System was installed in Shonai Town just 2 months before
the earthquake in June. The government of Shonai Town should pay
continuous effort for raising residents’ understanding of the broadcasting
ways of EEW.
3. I knew
neither its
name nor its
meaning
17.9%

2. I knew only
the name of
EEW
33.4%

1. I knew boththe name of
EEW and its
meaning
48.7%

Figure 7: Respondents’ knowledge on EEW before earthquakes
4. I didn't know
anything
16.7%

2. I knew thebroadcasting
only by TV
43.1%

1. I knew thebroadcasting byboth TV andloudspeakers
27.3%

2. I knew thebroadcasting
only byloudspeakers
12.9%

Figure 8: Respondents’ knowledge on broadcasting ways of EEW
before earthquakes

4. RESIDENTS’ HEARING OF EARTHQUAKE EARLY WARNING
Here, residents’ activities when the EEW was broadcasted wereasked. Figure 9 shows where they were at two earthquakes. When the
Iwate-Miyagi Inland Earthquake occurred in the Saturday morning, 65% of
the respondents were at home. At that time, 30% of the respondents werewatching TV and 40% were working at the office or at home. When anotherearthquake occurred in the midnight in July, 79% were staying at home andthat was higher than in June. At that time, 63% of the respondents were
sleeping and 16% were watching TV. Only 9% were working at the officeor at home.
Table 2 and 3 show how residents heard EEW at the both
earthquakes. At the earthquake in June, 63.9% heard EEW broadcasted by
loudspeakers. Compared with the 31.2% who watched EEW on TV, thenumber of respondents who heard EEW by loudspeakers was larger. It
suggests that loudspeakers can effectively convey EEW information to a lotof people although TV can alert only if its power is on. At the earthquake in
A Survey on Residents’ Response to Earthquake Early Warning at the 2008 Iwate-Miyagi Inland Earthquake in Japan

655

October 2009, Incheon, Korea

July, the percentage of the residents who heard by loudspeakers were larger
as it was in the midnight. Figure 10 shows how clearly residents heard EEWat the both earthquakes. At the earthquake in June, 30% heard both chimesound and warning saying “Big Earthquake”. 11% heard only warning
saying “Big Earthquake”. 22% could not catch the word although they heardsome sound from loudspeakers. 23% didn’t hear anything and 14% didn’t
remember. At the earthquake in July, the ratio of the residents who didn’t
remember was larger than in June as more people were sleeping in themidnight.
Figure 11 shows the relation between their hearing of EEW and theiractivities at the earthquake in June. Among the 164 respondents who heard
both chime sound and the warning words, 86.6% heard them at home. On
the other hand, among the 116 respondents who didn’t hear anything, 39%
were at home, 23% were in their office or school and 18% were driving a
car or a motorbike. It shows that EEW is sometimes difficult to catch whenpeople are in the middle of working inside the buildings or driving.
June 14

July 24
0%
1%
2%
8%
2%

0% 4% 3%
6%
7%

2%
6%

5%
10%
65%

79%

N=572

N=564

1, Home
3. Other buildings
5. Inside a Car or on a motorbike
7. Others

2. Office or School
4. Outside buildings
6. Inside a train or bus
8. I don't remember

Figure 9: Ratio of where respondents were at two earthquakes
Table 2: Ratio of how residents heard EEW on June 14
I watched on TV
No
Sum
128
212
340
24.1%
39.8%
63.9%
38
154
192
7.1%
28.9%
36.1%
166
366
532
31.2%
68.8%
100%

Yes
Yes
I heard by No
loudspeakers
Sum

Table 3: Ratio of how residents heard EEW on July 24
I watched on TV
No
Sum
56
216
272
10.5%
40.6%
51.1%
33
229
262
6.2%
43.0%
49.2%
89
445
532
16.7%
83.6%
100%

Yes
Yes
I heard by No
loudspeakers
Sum

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New Technologies for Urban Safety of Mega Cities in Asia

June 14

July 24

14%

22%
29%

30%

23%

8%

11%
22%

20%

21%

N=532

N=534

1. I heard both chime sound and warning words
2. heard only warning words
3. I could not catch the word although I heard some sound
4. I didn’t hear anything
5. I didn’t remember

Figure 10: Ratio of how clearly residents heard EEW
5. I didn’t remember

44

7 532011

4. I didn’t hear anything

45

27

3. I could not catch the word although I
heard some sound10 5 21 71

97

2. heard only warning words

41

8 14421207 241

1. I heard both chime sound and warning
words

127
0

20

40

60

7 8 16 240
80

100 120 140 160 180

1, Home2. Office or School

3. Other buildings
5. Inside a Car or on a motorbike

4. Outside buildings
6. Inside a train or bus

7. Others

8. I don't remember

Figure 11: Relation between respondents’ hearing of EEW
and their activities at the earthquake in June

4. RESIDENTS’ RESPONSE TO EARTHQUAKE EARLYWARNING
4.1 Response to Earthquake Early Warning at the earthquake in July
Then, residents’ response to the EEW was asked. Here, we focusedon the response to the EEW in July because the EEW in June failed inbroadcasting before the arrival of strong tremors as shown in Figure 3.
Figure 12 shows what respondents did just after hearing EEW. Blue
parts correspond to the 157 respondents who heard chime sound or thewarning words. Red parts correspond to the 214 respondents who could notcatch the words although they heard some sound from loudspeakers andwho didn’t hear anything. Most of the respondents tried to get earthquake
information by TV or radio nevertheless they heard EEW or not. About 40%
waited and about 25% informed their children or people near them of EEW.
Aim of the EEW service is to enable people to quickly protect themselves

A Survey on Residents’ Response to Earthquake Early Warning at the 2008 Iwate-Miyagi Inland Earthquake in Japan

657

October 2009, Incheon, Korea

before the arrival of strong tremors. However, very few residents tried toprotect their bodies, protect their children and elder family members. It
shows that their understanding of the meaning of EEW and their capacities
to take appropriate response were insufficient.
Between two types of respondents, the difference of their respond
was verified by the chi-square method. Asterisk marks * in the figure 12
shows that the responses were different with statistical significance as aresult of chi-square test. In case that the respondents heard EEW, thepercentages of the action such as “tried to get earthquake information by TV
or radio”, “didn’t remember”, “opened the door or window.” and “wentoutside home or the building” increased compared with the case that the
respondents didn’t heard EEW. It is thought that these responses were
promoted by the hearing of EEW. However, the responses such as “opened
the door or window.” and “went outside home or the building” sometimes
cause the possibilities of secondary casualties. Instead of these responses,
actions such as “protect their bodies” or “inform children or people nearthem of EEW” should be promoted by the hearing of EEW. From theseresults, it is said that education of public people on appropriate response to
EEW is necessary.
0%

20%

40%

60%

*Got information by TV or radio

53.3%

Held furniture and valuables

1.3%
0.5%

Hide in safe place and protect body

1.3%
1.9%

Held up my body

0.0%
0.5%
40.8%
36.0%

Waited and saw the situation

25.5%
20.6%

Informed children or others of EEW*Opend the door or window*Went outside home or the building

3.8%
3.7%
15.3%
8.9%
7.6%
3.3%

Stoped a car or a motorbike

0.0%
0.9%

Others0.0%
1.9%

I did nothing*I don't remember

66.9%

10.8%
9.8%

Put off fireProtected children, elder people

80%

8.9%
15.4%
1.9%
8.4%

I heard EEW
I didn't hear EEW

Figure 12: Ratio of responses after hearing EEW
4.2 Response to future Earthquake Early Warning
Finally, they were asked about what they would do if anotherearthquake same as the Iwate-Miyagi inland earthquake occur and they get
EEW 10-20 seconds before the arrival of strong tremors. Figure 13 showstheir answers. 79% of the respondents answered that they would put off fire.
It was higher than that of the answer “I will get earthquake information by
TV or radio”. It is understood that the response putting off fire was few as
the earthquake in July occurred in the midnight. Now in Japan, gas system

658

New Technologies for Urban Safety of Mega Cities in Asia

usually has automatic shut-down system in case of an earthquake.
Considering the safety of people as the first priority, it is not necessary to
put off fire just after an earthquake because these actions might cause
secondary casualties. High percentage of putting off fire means people’s
misunderstandings of the current gas system. The percentage of the answer“I will hide in safe place and protect my body” was 47% and fourth largest.
Compared with its low percentage in figure 12, it is said that people
understood the necessity of protecting their bodies although they could not
really respond as they thought.
In order to understand the difference of the answers by sex, ages,
experience of past earthquakes, their anxiety for earthquakes and existenceof their family members who need help in case of an earthquake, chi-square
tests were carried out. Table 4 shows the p-value of chi-square test in eachcase. Pink, orange and yellow parts were verified to be statisticallysignificant with the probability of 5%, 1% and 0%, respectively. The
Answer “I will put off fire” increased in case that they experienced pastearthquakes. Their past earthquake experience might cause
misunderstanding although recent gas system is not necessary to put off due
to the automatic shut-down system. The answer “I will hide in the safe place
and protect my body” increased as they were young. The Answer “I will
inform children or people near me of earthquake occurrence” increased incase of female or respondents who have anxiety for earthquakes. It
decreased in case of they were more than 70 years old. The Answer “I willprotect children, elder and sick people” increased if they have infants, smallchildren and elder family members who cannot walk by themselves. The
answer “I will open a door or window” increased in case of female
respondents. Any difference was observed for the answer “I will holdfurniture or valuables in order to prevent falling down”, “I will hold up mybody by catching something”, “I will stop a car or motorbike”. It is said that
potential trends of responding EEW are different according to theircharacteristics.
61.5%

Get information by TV or radio

79.0%

Put off fire
4.1%

Hold furniture and valuables

47.0%

Hide in safe place and protect body
5.5%

Hold up my body

18.4%

Wait and see the situation

57.2%

Inform children or others of EEW
35.0%

Protect children, elder people

39.8%

Opend the door or window
22.8%

Go outside home or the building

13.4%

Stop a car or a motorbike
0.2%

Others
0%

25%

50%

75%

100%

Figure 13: Response to future EEWTable 3: Ratio of how residents heard EEW on July 24

A Survey on Residents’ Response to Earthquake Early Warning at the 2008 Iwate-Miyagi Inland Earthquake in Japan659

October 2009, Incheon, Korea

Table 4: Ratio of how residents heard EEW on July 24
Resoinse to future
EEW
Get information by
TV or radio
Put off fire
Hold furniture andvaluables
Hide in safe place
and protect body
Hold up my body
Wait and see thesituation
Inform children orothers of EEW
Protect children,
elder people
Opend the door orwindow
Go outside homeor the building
Stop a car or a
motorbike

Sex

Age

Experience of
past disasters

Anxiety forearthquakes.378

Existence of theirfamily members
who need help

.933

.003

.418

.103

.000

.315

.173
.023

.220

.464

.846

.780

.813

.023

.000

.005

.006

.001

.663

.063

.377

.223

.082

.013

.440

.116

.410

.416

.000

.000

.028

.001

.008

.355

.002

.094

.281

.000

.000

.695

.021

.385

.050

.112

.567

.534

.287

.433

.222

.178

.660

.620

.897

5. CONCLUSIONSThe 2008 Iwate-Miyagi Inland Earthquake was the first earthquake
since October, 2007 that EEW could be broadcasted before the arrival ofstrong tremors. Shonai town, Yamagata prefecture was one of the regions
where EEW was broadcasted by loudspeakers using J-Alert system. In thisresearch, a questionnaire survey was conducted in Shonai Town in order tounderstand residents’ response to the warning. 800 questionnaire sheets
were distributed in the town and 591 answers were obtained in October
2008.
Regarding residents’ knowledge on EEW, only 48.7% knew both thename of EEW and the meaning. The ratio of the respondents who knew thebroadcasting of EEW by loudspeakers was less than half. These low
percentages suggest the necessity of popularization of EEW knowledge
among residents. At the earthquake in June, 63.9% heard EEW broadcasted
by loudspeakers. Among the respondents who didn’t hear anything, 39%
were at home, 23% were in their office or school and 18% were driving a
car or a motorbike. EEW is sometimes difficult to catch when people are in
the middle of working inside the buildings or driving.
When we focus on the response to EEW in July, most of the
respondents tried to get earthquake information by TV or radio. Very few
residents tried to protect their bodies, protect their children and elder family
members. It shows that their understanding of the meaning of EEW andtheir capacities to take appropriate response were insufficient. On the other
hand, when the response to future EEW was asked, 79% of the respondents
answered that they would put off fire. Its percentage increased in case thatthey experienced past earthquakes. High percentage of putting off firemeans people’s misunderstandings of the current gas system because it is
not necessary to put off fire thanks to the automatic shut-down system.

660

New Technologies for Urban Safety of Mega Cities in Asia

From the chi-square tests on future response by respondents
characteristics, several deference were statistically verified according totheir sex, ages, experience of past earthquakes, their anxiety for earthquakes
and existence of their family members who need help in case of anearthquake. In order to enable people to take proper actions to future EEW,
education on what the proper actions are at various situations should be
provided considering the potential trends of their responses observed in thissurvey.
In the future study, authors continue questionnaire survey for other
EEW examples and accumulate the data regarding human behaviors to
EEW. Based on these results, education material for increasing people’s
capacity to respond EEW will be developed in the future.

REFERENCES
The Fire and Disaster Management Agency, 2009.3. Newsletter of the Fireand Disaster Management, Japan.
The Fire and Disaster Management Agency, 2009.7. Report on the damage
due to the 2008 Iwate-Miyagi Inland Earthquake, 78th edition, Japan.
The Japan Meteorological Agency: A list of Past Earthquake Early Warning,
Website: http://www.seisvol.kishou.go.jp/eq/EEW/kaisetsu/joho/joho.html
Kyoshin-Net, the National Research Institute for Earth Science and Disaster
Prevension(NIED), Website: http://www.k-net.bosai.go.jp/

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661

SEISMIC MICROZONATION OF
COX’S BAZAR MUNICIPAL AREA
A. B. AFIFA IMTIAZ1 and MEHEDI AHMED ANSARY2
Dept. of Civil Engineering, BUET, Bangladesh
1
afifaimt@gmail.com, 2ansary@ce.buet.ac.bd
ABSTRACT
Cox’s Bazar lies in the Southeastern part of Bangladesh, beside the
Bay of Bengal. The area, having been a great tourist resort, has experienced
a rapid urbanization in the last few decades including various
establishments, construction of significant number of buildings and otherstructures in an unregulated manner and without seismic design
considerations. Landslide and related casualties have also become very
common in the hilly areas of the locality. In order to assess seismic
vulnerability based on ground susceptibility and adopt mitigation strategies
for urban areas, seismic microzonation is considered to be the first step.
This study deals with the microzonation of the Cox’s Bazar Municipal Area
using geographic information system (GIS) where reflection of groundshaking and the site attributes of soil amplification, liquefaction andlandslide are the salient features. The probable earthquake hazard andexpected ground motion for this area were assessed using probabilistic
approach. The liquefaction potential was estimated from Standard
Penetration Test (SPT) following the methods suggested by Seed and Idriss
combined with Japanese Code of Bridge Design. SHAKE analysis was
performed for estimation of 1D site amplification. Slope stability analyses
were performed for samples from the hilly regions of the area using the
program XSTABL. The results obtained for site amplification, liquefaction
and landslide potential were exported in GIS environment and presented as
microzonation maps.
The findings of the study show that the rock level Peak GroundAcceleration (PGA) of the area is 0.18g for a 7.5 magnitude earthquake
having a return period of 200 years. The surface PGA could be as high as
0.41g for an average 2.3 times amplification factor. Due to ground shaking
amplified by 2, 2.5 and 3 times, respectively 47%, 42% and 11% of themunicipal area can be affected. 87% of the study area is highly susceptible
to liquefaction. Approximately 8% of the municipality consists of hilly
region whose 97% is very unsafe regarding natural slope stability.
1. INTRODUCTION
Bangladesh, being located close to the boundary of two seismically active
plates: the Indian plate in the West and the Eurasian plate in the East andNorth, is always under a potential threat of earthquake. In the seismic
zoning map of Bangladesh, provided in BNBC (Bangladesh National
Building Code, 1993), Cox’s Bazar is shown under Zone II with design
peak ground acceleration (PGA) value of 0.15g (Z=0.15). This level of663

October 2009, Incheon, Korea

acceleration may be considered as equivalent to a seismic intensity between
VII and VIII. Historical information reveals that earthquakes of magnitude
between 6 and 7 have occurred around the area in the past. The frequent
earthquakes in and around the country, particularly Chittagong and Cox’s
Bazar regions, also point toward the potential of such intensity earthquakes,
even much higher and the consequences can be catastrophic to this area.
It is well known, and widely accepted amongst the earthquake engineeringcommunity, that the effects of surface geology on seismic motion exist andcan be large. Nearly all recent destructive earthquakes have brought
additional evidence of the dramatic importance of site effects. Accounting
for such "site effects" in seismic regulations, land use planning or design ofcritical facilities thus has become one goal of earthquake hazard reduction
programs. Local soil effects can amplify the ground motion and thus lead tointensity greater than the projected ones in certain areas causing moredamage. Liquefaction phenomena can affect buildings, bridges, buried
pipelines, lifelines and other constructed facilities in many different ways.
Landslide has become very common in the hilly areas of Southeastern
Bangladesh. Every year especially in the rainy season landslides take placein both natural and man-induced slopes. The loss of lives and properties due
to landslide events in Cox’s Bazar is also very significant. Seismic hazard
due to local site effects such as soil amplification, liquefaction, andlandslide can be estimated by combining the available soil parameter datawith the current hazard status of the region. Moreover, for accomplishingcomprehensive regional hazard assessment, geographic information system(GIS) provides a perfect environment. Therefore this study deals with themicrozonation of Cox’s Bazar Municipal Area using geographic
information system based on ground shaking and the site attributes of soil
amplification, liquefaction and landslide as the salient features.
2. COX’S BAZAR MUNICIPAL: THE STUDY AREA
2.1 Overview
Cox's Bazar is the only sea resort; a fishing port and a district
headquarter of Bangladesh. It is known for its wide sandy beach which isclaimed to be the world's longest natural sandy sea beach. It is located along
the Bay of Bengal in Southeastern Bangladesh and 150 km South of
Chittagong. Cox's Bazar municipality covers an area of 6.85 sq km with 27
mahallas and 9 wards and is bounded by Bakkhali River on the North andEast, Bay of Bengal in the West, and Jhilwanja Union in the South.
Population of the area is 51,918 (BBS, 2007). As one of the most beautiful
and famous tourist spots of Bangladesh, the major source of economy of
Cox's Bazar is tourism. Millions of foreigners and Bangladeshi natives visit
this coastal town every year. Therefore, a number of hotel, guest house, andmotel are built in this locality.
An important issue in developing a seismic microzonation map is theselection of an appropriate geographical reference, or geo-code, which will

664

New Technologies for Urban Safety of Mega Cities in Asia

generally be driven by the availability of input data regarding soil conditions.
Recently Cox’s Bazar municipality has been expanded and theadministrative map has not been finalized yet. For this study the proposed
map as of January 2009, was collected from Municipal Office where total
area is divided in to 9 wards. The map is shown in Figure 1. The existing
municipal map was scanned and was converted into digital map.

Figure 1: Boundary Map of Cox’s Bazar Municipal area
2.2 Geology
The landmass of the district of Cox's Bazar includes two distinct
geological settings namely Tertiary folded belt and coastal deposits. The
tertiary folded belt extends North-South as part of the Indo-Burmese mobile
belt, which is characterized by long narrow folds (Alam et al 1990). Cox’s
Bazar area lies within the Eastern flank of Inani Anticline, trending towards
NNW-SSW, whose Western Flank is eroded. Figure 2 shows the Surface
Geology of Cox's Bazar Municipal area after Alam et al (1990).

Figure 2: Location and Surface Geology of Cox's Bazar Municipal
Area (after Alam et al, 1990)
Six Lithostratigraphic units were observed forming the surface
geology of the area, from the Geological Map of Bangladesh. The Figure

Seismic Microzonation Of Cox’s Bazar Municipal Area

665

October 2009, Incheon, Korea

reveals that the area is predominantly composed of Valley Alluvium and
Colluvium and Dihing Formation of Pliocene-Pleistocene age. Rocks of thePliestocene, Pliocene and Neogene ages are also exposed in the area which
is mostly composed of sandstone and claystone. To the West-most of themunicipal boundary, the strand of Coastal Deposit, Beach and Dune Sandlies. This formation uncomfortably overlies Late Tertiary formations. To theEast of Beach and Sandstone, there lie narrow zones of Boka Bil Formation
and Tipam Sandstone of Neogene age. The South Eastern part of the town
has basically Dihing Formation Bedrock. Dupi Tila Formation ofPleistocene and Pilocene age lies to the south of Dihing Formation whichmight have a slight influence in the surface geology of the area.
2.3 Seismicity
The seismic hazard is typically determined using a combination ofseismological, morphological, geological and geotechnical investigations,combined with the history of earthquake in the region. Figure 3 shows the
distribution of faults and lineaments capable of producing damaging
earthquakes in and around Bangladesh. Here two major fault systems,
Chittagong Fault system and Sitakunda Teknaf Fault system are observed tolie around the Cox’s Bazar area.

Cox’s
Bazar

Figure 3: Seismo–tectonic lineaments and faults(after Ali and Choudhury, 1992;Whitney, 2004, CDMP-UNDP, 2009)
Historical data for seismic activity affecting Cox’s Bazar andsurrounding area shows that the area has undergone frequently throughearthquakes of magnitude ranging from 5 to 6 in Richter scale. Epicenters ofthese earthquakes with reference to the 250 km radius of the municipality
area reveal that the earthquake with the highest magnitude (6.5 in Richterscale) occurred in this region in 1955. Again, considering 450 Km radiusaround the study area, it is observed that the highest magnitude earthquakes
experienced occurred in 1664, 1858, 1912 with magnitudes 7.8, 7.66, 7.9
consecutively (after Ansary, 2009). Fig 4 shows that earthquakes having
magnitude higher than 5, are recurring in almost every decade in this region.

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New Technologies for Urban Safety of Mega Cities in Asia

Again the frequency of earthquakes with magnitude varied from 4 to 5 has
increased markedly over the last four decades.

Figure 4: Earthquake Occurrences in and around Cox’s Bazar (1919-2008)(after Ansary, 2009)
3. SEISMIC MICROZONATION
Seismic microzonation can be defined as the subdivision of a region into
zones that have relatively similar exposure to various earthquake related
effects. It is the mapping of seismic hazard at local scales to incorporate theeffects of local soil conditions. In general terms, it is the process for
estimating the response of soil layers under earthquake excitations and thus
the variation of earthquake characteristics on the ground surface. Seismic
microzonation is the initial phase of earthquake risk mitigation and the final
output contains recommendations suitable for application by local
administrators, urban planners and engineers. A Seismic microzonation
study consists of four stages: (1) estimation of the regional seismic hazard
that is asessment of the expected input motion, (2) determination of the local
geological and geotechnical site conditions (3) assessment of the probableground response and ground motion parameters on the ground surface (4)finally, preparation of microzonation maps.
4. DATA COLLECTION
4.1 Geotechnical Data
A total of 26 borehole SPT data were used to study site amplification
as well as soil liquefaction potential characteristics of municipality area.
Among them, twelve subsoil investigations up to a depth of 15 metres werecarried out under the current study. The borings were drilled vertically using
the wash boring technique and equipment capable of pushing tube samplers
by hydraulic pressure. SPT was carried out in each boring at nominal 1.5 m
intervals and the N-values, i.e., number of blows count for each standard
penetration was counted. The other fourteen boreholes’ SPT data up to a

Seismic Microzonation Of Cox’s Bazar Municipal Area

667

October 2009, Incheon, Korea

depth of 30 metres were collected from a research project on Cox’s Bazar
District, carried out under the Department of Civil Engineering, BUET in
2007-2008 (Dhar et. al., 2008). Figure 5 shows borehole locations ofprimary (current study) and secondary (previous study) source points ofborehole SPT data. All the boring data include SPT N- values measured at
1.5 m interval. To obtain soil parameters such as grain size (soil type andD50) grain size analyses of the SPT samples of different depth were
performed in the laboratory.
4.2 Landslide Estimation Data
Hill ranges and hillock mainly appear to the Northern part of the
Cox’s Bazar municipal area. Baillarpara, Ghonarpara, Baiddorghona,
Pahartali, Light House Para, Bus Terminal, Saikat Para, Kolatoli areas of themunicipality are mainly consisted of these hillocks. These hills range from15 meters to 40 meters in height. Hilly regions of this area were surveyed
and location, height, slope and other relevant data were collected. The
slopes of the hills range from 45 degree to almost 90 degrees. Most of thehill ranges contain some eroded slopes with almost vertical positioning.
Dense population, houses and even multistoried buildings were observed onthese eroded slopes and at their vicinity. Eleven disturbed samples fromdifferent locations of the area were collected for laboratory investigations
including specific gravity test, grain size analysis, Atterberg’s limits,standard compaction test and direct shear test. Figure 5 shows the locationsof the sampling points from the hills.

Figure 5: Cox’s Bazar Municipal Map Showing Soil Sampling Locations
5. ASSESSMENT OF SEISMIC HAZARD
Seismic hazard analysis involves the quantitative estimation of groundshaking hazards at a particular area. A critical part of seismic hazard
analysis is the determination of Peak Ground Acceleration (PGA) for an
area/site. Numerous methods for earthquake hazard assessment in a given

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New Technologies for Urban Safety of Mega Cities in Asia

site are available today. In this study, point source is used as Earthquake
Source Model. The seismicity of each of the modelled sources is first
determined from past data available. The recurrence relationship relating thesize of the past events in terms of Magnitude (M) and Peak GroundAcceleration (PGA) is derived. The seismicity model used in Molas andYamazaki (1994) is usually taken aslog(ν) =a+b*Mlog(ν) =a+b*log(y)

(1)
(2)

where M is the earthquake magnitude, y is the peak ground acceleration, ν isoccurrence rate per year and a and b are regression constants. T (=l/ν) is thereturn period in years.
Evaluation of seismic parameter was carried out using the seismic data overan area having a 250 km radius around Cox’s Bazar Municipal (Figure 6).
The historical earthquakes around the study area and their magnitude,
epicentral distance, focal depth and intensity are considered to estimate
PGA (%g).

Figure 6: Historical Earthquakes around Cox’s Bazar Municipal
Since no PGA based attenuation law was developed yet for Bangladesh, themethodology used in few previous studies (Sabri 2001, Sharfuddin 2001)
was followed to select the most suitable attenuation law for predicting rockmotions. McGuire (1978) equation for rock, which was observed to follow
the PGA trend of most large earthquakes in and around Bangladesh, wasthus selected for this study. The equation is:
PGA =0.0306 e 0.89M r-1.17(3)
Where, M is earthquake magnitude and r is hypocentral distance.
Seismic parameter b was evaluated from G-R relationship (Gutenberg andRichter, 1944), a method utilizing extreme, instrumented and complete

Seismic Microzonation Of Cox’s Bazar Municipal Area

669

October 2009, Incheon, Korea

catalogs. Figure 7 and 8 show the regression curves fitting for Cox’s Bazar
Municipal. The hazards in terms of the rock level PGA values and probable
earthquake magnitude corresponding to return periods of 200 years arequantified from Equations (1) and (2) as, 0.18g and 8.26 consecutively.
Since the largest Magnitude earthquake around the 350-450 km radius of thestudy area is 7.9 and around 250 km radius is 6.5, a cut-off Magnitude of 7.5
earthquake was considered as the expected one in 200 years.

Figure 7: PGA versus Mean
Occurrence Rate for the study area

Figure 8: Magnitude versus Mean
Occurrence Rate for the study area

6. ESTIMATION OF GROUND SUSCEPTIBILITY
6.1 Analysis of Site Amplification
It is well known that the surface ground motion of earthquakes isheavily influenced by the subsurface ground condition, especially in areas
covered by thick sediments. Thus evaluation of the difference in subsurface
amplification for each site is important to know the distribution ofearthquake motion across the study area. For site amplification analysis,
shear wave velocity for 26 borehole data up to a maximum depth of 30m
were calculated by using equation of Tamura and Yamazaki (2002)
presented in Equation (4). The engineering bedrock was assumed to be thelayer at which the shear wave velocity (Vs) exceeds 400 m/s, which exist
almost 30 m deep from the surface of the study area. The calculations showthat the shear wave velocities at bedrock level vary from 400 m/s to 500 m/s.
Vs = 105 N0.187 D0.179(4)Where Vs = Shear Wave Velocity (m/s); N = Corrected SPT blow count andD = Depth (m).
One dimensional wave propagation program SHAKE (Schanabel et.
al., 1972) was employed to estimate the vibration characteristics at different
points. An estimation of the fundamental frequency and the maximum valueof the amplification were obtained at each site from plot of transfer
functions. Typical graphical representation of frequency versus amplitude isshown in Figure 9.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 9: A sample plot of transfer function for the study area
6.2 Analysis of Liquefaction Potential
Evaluating the maximum amplification values for different locations,average amplification factor for the study area was estimated as 2.3. Thus
the maximum ground surface acceleration was estimated as 0.41g by
multiplying the PGA at bedrock level (0.18 g) with amplification factor.
Particle diameter data for a particular depth of soil was obtained from grain
size distribution curves. A simple method suggested by Seed and Idriss(1971) was used here to evaluate the Liquefaction Resistance Factor, FL
which can also be termed as Factor of Safety and defined as a ratio of Cyclic
Resistance Ratio (CRR) to Cyclic Stress Ratio (CSR). Liquefaction isassumed to occur at that depth if FL is less than 1.0. Here, CRR is the in-situ
capacity of soil to resist liquefaction for earthquake of magnitude 7.5 andCSR is the earthquake load induced by a seismic motion. CRR isdetermined based on corrected SPT (Seed et al. 1983). The severity offoundation damage caused by soil liquefaction depends to a great extent on
the severity of liquefaction, which cannot be evaluated solely by the FL. In
order to take care of this effect, the Japanese Bridge Code (Japanese Road
Association, 1991) recommended a modification to the procedure suggested
by Seed et. al., (1971). Following this procedure, the liquefaction resistancefactor for the top 20m depth of soil, expressed as liquefaction potential
index (IL) (Iwasaki et al., 1982), for the 26 sites were calculated. The area
was divided into different zones based on the range of the values IL
suggested by Iwasaki et. al., (1982). From the analysis no liquefaction
potential index value was found in the range of ‘moderate’ zone. Therefore
study area was characterized into three zones namely, high, low probabilityof liquefaction zones and non-liquified zones.
6.3 Analysis of Landslide Potential
XSTABL, a fully integrated slope stability analysis program was used
for stability analysis in this study. XSTABL performs two dimensional limit
equilibrium analysis to evaluate the Factor of Safety (FS) for a layered slope
using the simplified Bishop Method. The strength parameters of the slope
and foundation materials required for the analyses were obtained fromconsolidated undrained direct shear tests performed on soil samples. The

Seismic Microzonation Of Cox’s Bazar Municipal Area671

October 2009, Incheon, Korea

minimum values of undrained cohesion (cu) and undrained angle of internal
friction (φu) were used in the slope stability analyses. The location of thewater table in all the slope sections was assumed to be well below the toe ofthe slopes. The height of the slopes were considered as 30 m (100 ft) which
was observed from field survey as the average height of the hills of Cox’s
Bazar. Generally the slopes were found to be 60° to 80°. Considering humanactivities and ongoing hill cutting activities the average slope of the hills
were assumed to be 70° on an average. From the analyses it was observedthat only single data contained the representative value of ‘satisfactory’(FS=1.44) and the rest were ‘unsafe’ (FS<1). Thus the landslide potential
was categorized as ‘high’ and ‘low’ for FS being greater than or equal to 1.2
and less than 1.2 consecutively. Figure 10 shows two hill locations studied
for landslide potential.

(a)

(b)

Figure 10: (a) Ghonerpara Hill, FS = 0.31; (b) Lighthouse Hill, FS= 0.69
7.

GENERATION OF MICROZONATION MAPS

The computed results from the analyses were exported to a GIS
environment and were plotted using spatial interpolation among theborehole locations and converting the vectorial point features into
continuous raster map through grid generation. The developed
microzonation maps are shown as Figure 11 to Figure 14.

Figure 11: Microzonation map based on fundamental frequencies

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 12: Microzonation map based on amplification

Figure 13: Microzonation map based on liquefaction potential
21. 46 N

li R
ha
kK
Ba

N

r
ive

21.45 N

W 01

W 08

W 03

W 02

CP

W 04

W 07

21.44 N
y
Ba

W 06

W 05

al
ng
Be
of

W 09

To
C

hit
tag
on
g

M

y
Ba

oo
re

21.43 N

2

ha
ri
To

1

Him
ch

al
ng
Be

Ko
la
to

li

of

0

kilometres
91.95 E

91.96 E

91.97 E

21.42 N
91.98 E

91.99 E

92.00 E

Figure 14: Microzonation map based on landslide potential

Seismic Microzonation Of Cox’s Bazar Municipal Area673

October 2009, Incheon, Korea

8. SEISMIC HAZARD INTEGRATION
The most important endeavor of this study is the estimation of seismic
hazards linked with the local site attributes of soil amplification,liquefaction, and landslide and then integrating them in such a manner sothat a reflection of probable actual disaster consequences can be represented.
Since every analysis region is different; the quantification of the secondarysite effects and the weighting scheme for combining the various seismic
hazards is considered to be heuristic, based on judgment and expert opinion
about the influence of local site conditions in the region and the accuracy of
the available geologic and geotechnical information. The seismic intensity isbasically a subjective one, based on the human sensations or damage during
an earthquake. It is assumed that the final combined seismic hazard would
be quantified in terms of Modified Mercalli Intensity (MMI).
First the regional distribution of ground shaking hazard (MMIGS)
considering 2.0, 2.5 and 3.0 times amplification of the surface PGA wascalculated. The equation used here to convert PGA to intensity is developedby Trifunac and Brady (1975) and is given by equation (5). The MMI scale
is subjective and assigned as integer values, therefore the MMIGS values arerounded to the nearest 0.5.
log PGA = 0.014+0.3 * I(5)where, I = Intensity of Earthquake
The heuristic rules were used to quantify the seismic hazards due toliquefaction and landslide. The rules for combining the various hazards wereadopted based on expert opinion (after Stephanie and Kiremidjian, 1994).
The final combined hazard (MMIF) was computed as a weighted sum of the
combination of various hazards. Figure 15 shows the regional distribution of
combined hazards. Figure 16 shows the variation of Intensity (MMIF) as aresult of the combined effect of the hazards.
21. 46 N

3 times Amplification+ High Liquefaction
2.5 times Amplification+ High Liquefaction
2 times Amplification+ High LiquefactionkBa

3 times Amplification+ Low Liquefaction

ive

N

r

21.45 N

W 01
W 02 W 03

CP

2.5 times Amplification+ Low Liquefaction

W 08

W 04

W 07

21.44 N
W 06

Ba
yo

W 05
To

W 09

fB
en
ga

Ch

itta

go

ng

l

2 times Amplification+ Low Liquefaction

R
ali
Kh

2.5 times Amplification+ High Landslide

21.43 N

To

Him

l

ch

ha

ga

ri

en

Ko

la

to

fB

li M

yo

oo

re

Ba

2.5 times Amplification+ Low Landslide
2 times Amplification+ High Landslide
91.95 E

21.42 N91.96 E

91.97 E

91.98 E

91.99 E

92.00 E

Figure 15: Map showing the zonation of the possible hazard combinations

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Intensity = X
Intensity = IX
Intensity = VIII

Figure 16: Map showing the regional distribution of combined seismic
hazard (MMIF)
9. CONCLUSIONS
From the developed microzonation maps, it can be observed that theSoutheastern end of ward no. 5 will experience the highest frequencies.
Ward no. 4 consisting of East Tekpara, Rumaliarchhara andTarabaniachhara might be affected by 3 times site amplification.
Liquefaction analysis for the study area reflects that it is susceptible to very
high liquefaction potential. From the borehole investigations and grain size
distributions, it was observed that the soil up to 20 meter depth is mostly
sandy having D50 ranging from 0.12 mm to 0.22 mm. It was observed thatthe sandy silts with trace clay, layer of silt and sand, silty sand having
greater particle diameters and low to medium SPT N-values showed higher
liquefaction potentials. According to the study, the landslide potential ofthis area is very high. Approximately 8.13% area under the municipality ishilly. The hills located in Ghonerpara, Boiddorghona, Pahartoli and
Boillarpara are found to be very unstable. The combined hazard analysis
shows that if the area experiences both ground shaking and liquefaction
during a scenario earthquake having a magnitude of 7.5, the area can beseverely affected and the intensity due to the combined effect of the hazards
can be as high as X in MMI scale. The town will be highly endangered(44% area is affected) if high liquefaction associates with amplification
factor as low as 2 times. On the other hand if 2.5 to 3 times site
amplification occurs, still there is a high risk (MMI = IX) even in case of
low liquefaction occurrence. The hilly region is highly susceptible to slope
instability, moreover, 77% of the hilly region is on the risk of experiencing
very high intensity (MMI = X), if 2.5 times amplification of ground shaking
occurs.
The developed maps can act as a guide for the authorities at the national andregional levels in land use management, revision and enforcement ofappropriate building codes and formulation of plans for mitigating measuresagainst earthquake risk affecting the region considered.

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October 2009, Incheon, Korea

REFERENCES
Alam M.K., Hasan A.K.M. and Khan M.R., (1990). Geological Map ofBangladesh. Geological Survey of Bangladesh, Govt. of the People’s Republic ofBangladesh
Ali, M.H. and J.R. Choudhury (1992). Tectonics and earthquake occurrence in
Bangladesh. 36th Annual Convention of IEB, Dhaka, January 1992.
Ansary, M.A. (2009). Earthquake Database of Bangladesh. Unpublished Report.
Department of Civil Engineering, BUET, Dhaka, Bangladesh
BBS (2007). Census results by municipality. Bangladesh Bureau of Statistics.
Available at www.bbs.gov.bd/dataindex/census/municip.pdf (accessed on 22.6.09)
BNBC (1993). Bangladesh National Building Code, HBRI-BSTI.
CDMP-UNDP (2009). Ongoing Research Work. CDMP-UNDP Fault Map
Delineation for Bangladesh, 2009.
Dhar, A.S., Ansary, M.A., Imtiaz, A.B.A., and Saha, R., (2008). Earthquake
Vulnerability Assessment of Cox's Bazar District. Report to United Nations Officefor Project Services (UNOPS). Department of Civil Engineering, Bangladesh
University of Engineering and Technology (BUET)
Gutenburg, B. and Richter, C. F. (1954). Seismicity of the earth and associatedphenomena. 2nd Edition, Princeton, Princeton University press.
Japanese Road Association (1991). Specifications for Highway Bridges, Part V.
Earthquake Resistant Design.
Iwasaki, T., Tokida, K., Tatsuoka, F. Watanabe, S., Yasuda, S. and Sato, H. (1982).
Microzonation for soil liquefaction Potential using Simplified Methods. 3rd
International Microzonation Conference, Proceedings, 1319-1329.
McGuire, R. (1978). Seismic ground motion parameters relations. Journal of
Geotechnical Division, ASCE, Volume 104, pp.461 – 490.
Molas, G. L. and F. Yamazaki (1994), Sesimic macrozonation of the Phillipines
based on sesimic hazard analysis. Journal of Structural Mechanics and Earthquake
Engineering, JSCE, 489 (I-27), 59-69.
Sabri, S. A., (2001). Earthquake intensity-attenuation relationship for Bangladesh
and its surrounding region. M.Engg. Thesis, BUET, Dhaka,Bangladesh
Schnabel, P.B., J. Lysmer and H.B. Seed (1972). SHAKE: a computer program forearthquake response analysis of horizontally layered sites. Report no. EERC 72-12.
Earthquake Engineering Research Center, Berkeley, California, 1972
Seed, H.B. and Idriss, I.M. (1971). Simplified Procedure for Evaluating Soil
Liquefaction Potential. Journal of the Soil Mechanics and Foundations Division,
ASCE, 97(SM9), 1249-1273.
Seed, H. B., I. M. Idriss and I. Arango (1983). Evaluation of liquefaction potential
using field performance data. Journal of Geotechnical Engineering, Volume 109,
No. 3, pp. 458-482.
Sharfuddin, M. (2001). Earthquake Hazard Analysis for Bangladesh. M.Sc. Engg.
Thesis, Bangladesh University of Engineering and Technology (BUET), Dhaka.
Stephanie, A. K., and Kiremidjian, A. S. (1994). Regional Seismic Hazard and Risk
Analysis through Geographic Information System.
Tamura, I. and F. Yamazaki (2002). Estimation of S-wave velocity based on
geological survey data for K-NET and Yokohama seismometer network. Journal of
Structural Mechanics and Earthquake Engineering, No. 696, Vol. I-58, 237-248(in Japanese)
Trifunac, M. D. and A. G. Brady (1975). A study of the duration of strong
earthquake ground motions. Bulletin of Seismological Society of America, Volume
65, pp. b581-626.
Whitney, J. (2004). GSB-USGS Workshop, November 13-16, Dhaka.

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DEVELOPMENT OF WINDRISK®;A TOOL FOR REGIONAL WINDSTORMRISK ASSESSMENTSUNGSU LEE1, HEE-JUNG HAM2, DONGHYUN LEE3,
YOUNGKYU LEE3, JASUP KOO3 and JINA JEONG3
1
School of Civil Engg., Chungbuk National University,
410 Seongbong-ro, Cheongju Chungbuk 361-763, Korea
joshua@cbnu.ac.kr
2
Division of Architecture, Kangwon National University,
Chuncheon 442-749, Kanwon-do, Korea
heejham@kangwon.ac.kr
3
Cubersolution co. ltd., Cheongju, Korea{dhlee,yglee,koojs613,koojs613}@cuber.co.kr
ABSTRACTThis paper presents the development of a computational tool forregional windstorm risk assessment, WindRisk®. Three representative
components form the tool, which are wind hazard, fragility and exposure.
The wind hazards are specified by three types; the long-term, the typhoonand the user-defined winds. The long-term wind hazards corresponding to30, 50, 100, and 200 year return periods are developed by extreme value
analysis and typhoon simulations over all Korean regions. The typhoon
winds are simulated by the empirical wind field model with data of thecentral pressures, the expecting track, and the radii of maximum winds. The
WindRisk® also reflects the effects of surface roughness surroundings using
the land cover map and topographic effects using the digital elevation
model (DEM). Fragility curves to wind-vulnerable properties such as panelbuilding structures, greenhouses and sheds are also incorporated into theprogram. The WindRisk® is applicable to the planning of budget to annual
damage recovery cost and to estimate the damage by typhoons.

1. INTRODUCTION
With continuing development and construction of industrial facilities, loss
and damage are widely spread and increasing due to natural disasters. For
instance, more than 10 billion USD are lost in two events during typhoon
RUSA (2002) and MAEMI (2003) in Korea [1]. Typhoons cause social
losses such as casualties and victims as well as economic losses. The loss isfurther expanded when the national efforts and the humane commitment inrecovery. Various efforts have been carried out to mitigate the damages andthe loss, among which is to assess and estimate the probable loss in prior to
the events of natural disasters. This paper describes one of the efforts, inwhich a computational tool, WindRisk® has been developed to assess
damages and losses due to windstorms.

677

October 2009,Inchoen, Korea

2. GENERAL PROCEDURE OF DEVELOPMENT
Three representative components form the tool, which are wind hazard,
fragility and exposure. Figure 1 depicts the general procedure in WindRisk®.
The tool, first assess the wind hazard in the region of interest, which
estimates the probable wind speed. Once the extreme or the probable windspeed is determined, the regional risk can be assessed using database for the
exposures and corresponding vulnerability.

Figure 1: General Procedure in WindRisk
3. WIND HAZARD ANALYSIS
The wind hazards are specified by three types; the long-term, the typhoonand the user-defined winds. The long-term wind hazards corresponding to30, 50, 100, and 200 year return periods are developed by extreme value
analysis and typhoon simulations over all Korean regions. The typhoon
winds are simulated by the empirical wind field model with data of thecentral pressures, the expecting track, and the radii of maximum winds . The
wind field model is based on the study of Batts et al (1980) and thecorrections made by Lee et al [3,4], which determine the maximum gradientwind, while the wind speed near the ground is estimated using the model
developed by NOAA [5]. Figure 2 shows the simulated wind speed over
Korean peninsula during typhoon MAEMI (2003).

Figure 2: Simulated Wind Speed during Typhoon MAEMI (2003)

678

Development of WindRisk; A Tool for Regional Windstorm Risk Assessment

3.1 Surface Roughness and Topography
Even if the extreme wind speed over the region of interest is estimated,
it considers only meteorological parameters not the local factors affecting
the wind speed near ground. The essential factors profiling the wind near the
ground are surface roughness and topography. Since wind, in general, slows
down in the region of rough surface such as forest and urban area, GIS
information of land use is utilized to account for the effects of surface
roughness on the wind speed. In this paper, SRM (Surface Roughness
Model) is developed based on the studies of Bietry et al (1978) andBuchene-Marullaz (1976). Upwind region is defined as the region up to
1000m in the direction of wind-coming according to KBC (2005) and
AS/NZS (2005).
Another important aspect of wind speed near ground is that the wind
tends to speed up when it approaches the crest of ridges or mountains due tothe mass conservation in fluid dynamics. In this paper, TEM (TopographicalEffects Model) is developed based on KBC (2005) and uses DEM (Digital
Elevation Model).
Figure 3 illustrates SRM and TEM over Korean peninsula assumingthat the wind blows from north.
3.2 Regional Wind Hazard
With GIS information of land use and DEM, the extreme wind speed
can be converted into the local wind near the ground, which represents forthe local wind hazard. In the program, WindRisk®, GIS engine isincorporated into the analysis to allow for convenient analysis. Figure 4
depicts the example of the wind hazard analysis in a small region.
4. EXPOSURES AND VULNERABILITY
Next steps to assess the windstorm risk are to gather information of
exposures, i.e., inventory of assets in probable danger and to determine thevulnerability of the assets to the hazard using fragility curves. The
exposures can be categorized into regional data or site-specific data, both ofwhich can be handled using GIS. Fragility curves to wind-vulnerable
properties such as panel building structures, greenhouses and sheds are also
incorporated into the program. WindRisk® utilizes the results of Lee et al(2007, 2009) to determine the failure probability in strong wind. Figure 5
exemplifies a fragility curve corresponding to a greenhouse in strong wind.

Development of WindRisk; A Tool for Regional Windstorm Risk Assessment679

October 2009,Inchoen, Korea

Figure 3: SRM (left) and TEM (right) in North Wind

Figure 4: GIS based Regional Wind Hazard Analysis
5. ASSESSMENT OF WINDSTROM RISKIn the developed tool, all the information is processed through GIS engine
with analysis module. Since the risk is defined as the probability of failureof regional assets or a site-specific asset, combination of wind hazard andvulnerability applied to the assets of interest yields the amount or the
probability of loss.
Figure 6 shows an example of windstorm risk map for a type of greenhouse
which is known to its vulnerability to wind.

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Development of WindRisk; A Tool for Regional Windstorm Risk Assessment

Figure 5: Fragility Curve of Greenhouse in Strong Wind

Figure 6: Failure Probability of a Greenhouse in Windstorm

6. CONCLUDING REMARKSThis paper presents development of a GIS-based computational tool toassess the regional windstorm risk. Using meteorological data andsimulation method, the extreme wind speed over a region of interest is
estimated as the hazard which is applied to the exposures of assets. Using
structural vulnerability, the results are the probability of failure whichcorresponds to the windstorm risk. . The WindRisk® is applicable to theplanning of budget to annual damage recovery cost and to estimate thedamage by typhoons.
REFERENCES[1] NEMA, Annual Reports for Disasters in Korea, 1991-2007.
[2] Batts, M.E., M.R. Cordes, C.R. Russell, J.R. Shaver, and E. Simiu, 1980,
Hurricane Windspeeds in The United States, National Bureau ofStandards Report Number BSS-124, U.S. Dept. of Commerce,
Washington, DC.

Development of WindRisk; A Tool for Regional Windstorm Risk Assessment

681

October 2009,Inchoen, Korea[3] YK Lee, S Lee and HS Kim, 2007, Expectation of Extreme Wind Speeddue to Typhoo, Proc. of WEIK, pp. 20 ~ 26.
[3] YK Lee, S Lee and CW Park, 2007, Analysis on Radii of Maximum
Sustained Winds of Typhoons around Korean Peninsula, J. WEIK,
Vol.11, No.2, pp. 203 ~ 210.
[4] NOAA, 1972, Revised Standard Project Hurricane Criteria for the
Atlantic and Gulf Coasts of the United States, Memorandum HUR7-120,
U.S. Dept. of Commerce.
[5] J Bietry, C Sacre and E Simiu, 1978, Mean Wind Profiles and Changesof Terrain Roughness, J. Struct. Div., ASCE, 104, 1585-1593.
[6] P Duchene-Marullaz, 1976, Full-Scale Measurements of AtmosphericTurbulence in a Suburban Area, Proceedings of the FourthInternational Conference on Wind Effects on Buildings and Other
Structures, London, Cambridge Univ. Press. Cambridge, pp. 23-31.
[7] Architectural Institute of Korea, “Korean Building Code”, 2005.
[8] J Holmes and A King, 2005, A Guide to AS/NZS 1170.2:2002, Wind
Action, Warren Publishing[9] S Lee et al, 2007, Development of Windstorm Vulnerability Functionsof Industrial Buildings, NIDP.
[10] S Lee et al, 2010, Development of Risk Assessment Technique forStrong Wind and Heavy Snowfall, NEMA.

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Development of WindRisk; A Tool for Regional Windstorm Risk Assessment

Development of an Intelligent Smoke
Control Procedure using HVAC Operation
and Door Control Strategy in a Building FireCHU YANYAN, ZHANG HUICenter of Public safety Research, Tsinghua University, Beijing, China
chuyan@mail.tsinghua.edu.cn
ABSTRACTIn a high-rise building fire, sprinkler is the first defense and smoke
exhausted system is the major equipment to control and reduce smoke.
Traditional smoke control procedure does not utilize the HVAC system anddoor control strategy. A modified smoke control procedure is proposed inthis paper using several closed systems to integrate door controllers, HVAC
controllers and smoke exhaust fan controllers based on real-time sensor
readings and video on occupants’ location and fire propagation. The newprocedure is capable of slowing down the smoke propagation and provides
favor conditions for occupants’ evacuation. In this paper, a zone model isused to study the smoke propagation under different modified control
procedures. Simulation results show that door controllers and HVAC
controllers can be utilized to manage the smoke movement and increase thesafety of occupants.
1. INTRODUCTION
In a building fire, smoke is often the leading cause of fatalities. Smoke cantravel a long distance from the fire room. In traditional smoke control
procedure, ventilation vents are usually closed to prevent fresh air fromentering fire room and sprinklers and smoke exhaust fan are usually turned
on. It is an open system that sprinklers, ventilation vents, smoke fan andother controllers could be operated in accordance with a predetermined
program. Much research has been performed focusing on how to control
smoke propagation in a building fire using different equipments andfacilities. Ventilation and extraction system drive the longitudinal motion of
the fire-induced smoke and to extract it efficiently in zones near the firesource. Air curtain could be utilized for confinement of fire-induced smoke
transportation along channels. Fire simulation results on the underground
shopping mall show that the location of mechanical exhaust vents andmechanical exhaust rate can significantly impact the smoke extraction.
Smoke control strategy with feedback utilizing all kinds of controllers may
prevent smoke propagation more effectively.
Since the evacuation of occupants is extremely difficult, it is important toutilize all means to slow down the smoke propagation and supply fresh air
to the place with occupants. Based on real-time occupants’ information andother sensor readings such as temperature and smoke concentration, amodified smoke control procedure is developed to assist evacuation and to683

October 2009, Incheon, Korea

improve building safety performance limit. The new procedure utilizes door
controller, ventilation vents, smoke exhaust fans and sprinklers according tosensor readings. The system can adjust control precepts, which can delay
smoke propagation, save time and improve air quality for occupants’evacuation from the fire building. A zone model is used to study the smoke
propagation with modified smoke control procedure. Simulation results are
performed to study the smoke height, carbon monoxide concentration andcarbon dioxide concentration at the fire room and corridors. Results show
the effectiveness of the modified smoke control procedure for smoke
propagation.
2. DEVELOPMENT OF CONTROL STRATEGY
2.1 Problem Setup
Air flow in the building can be moved by various equipments such as air
condition units, VAV box, smoke exhaust fan, etc. In traditional smoke
control procedure, fresh air valves in the fire floor are usually closed toprevent fresh air from entering fire room and air valves in fire neighborfloor are opened to supply air and assist evacuation. Back air valves in threefloors are closed to prevent smoke propagation through pipes. Once a fire is
detected in building, equipments in the fire floor, fire neighbor floors andrefuge areas are switched to the fire mode. This strategy makes no effort on
controlling smoke movement except for using smoke exhaust system, which
in many times is insufficient to pump the smoke out the building in a highrise building fire. Also no occupant information is utilized. In the modernbuilding, videos are widely used for security purpose. With video and othersensors, occupants’ location can be in-situ monitored during fire. It istherefore reasonable to direct the smoke into the empty rooms when smoke
exhaust system is insufficient. Together with door control and HVAC
operations, air environment of occupants may be improved so that safety ofoccupants may be improved.
A numerical model is developed in this paper to study the feasibility ofutilizing modified smoke control procedure to enhance the safety
performance limit of the building. A typical high-rise building floor consistsof an office zone and a core. Elevators, equipment rooms and evacuation
staircase lie in the core. The office zone is usually divided into several
rooms by the walls based on tenements requirement. Every office zone has
at least an exit to corridor. A typical layout is shown in Fig. 1. Building areaof the fire zone is set to be 2700 m2. Area of the office zone is about 2000
m2 and area of the central core is 700 m2. Building height of the fire zone isabout 4 m and clear height is 2.7 m. Locations of the doors are alsopresented in Fig. 1. Smoke extraction vents and VAV ventilators of HVAC
lie in office zone homogeneously. A fire is set at the right top room. We will
study the effect of modified control system on the smoke propagation anddiscuss the control strategy.

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Door 2

Corridor 2
Corridor1

Door 1

Corridor 3
Door 3

Door 4

Fig. 1 Schematic of Fire Scenario used in the Simulation
2.2 Mathematics ModelIn the zone model finite space is usually separated into two control volumes
or zones. It is assumed that all relative parameters of each control
volume/zone are consistent. Mass exchange between each interval is mainly
caused by smoke plume and flesh air. Radiation loss is also included inenergy besides the energy transmission by mass exchange. Differential
equations for conservation of mass equations and persistence of energy
equations are solved. Equations of the zone model are shown as follows:dmu= ∑ m& i,u
dt
i
（3）
dml
= ∑ m& i,l
dt
i

dp
d
(cp m& uTu ) = Vu u + cp we B ρTu − Q& u
dt
dt
dp
d
(cp m& lTl ) = Vl l + cp we B ρTl − Q& l
dt
dt

（4）
（5）
（6）

P = R ρiTi

（7）

V = Vl + Vu

（8）where subscripts ‘u’ and ‘l’ represent up and down volumes/zones,
respectively; V is dimension of the control volume; unknown variables
include mu 、 ml 、 Vu 、 Vl 、 Tu 、 Tl 、 pu 、 pl and mu = Z u Aρ u ，
ml = Z l Aρ l ， Vu = Z u A ， Vl = Z l A ; H is height of finite space
H = Zl + Zu .
3. DESIGN OF FIRE SCENARIOS
3.1 Development of Modified Smoke Control ProcedureYour Paper Title

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October 2009, Incheon, Korea

The modified smoke control procedure is shown in Fig.2. The key issue
here is that the occupants’ location should be able to detect in real time bysensors such as video, RFID, wireless systems. Door controllers can operate
the doors such as closing the doors of the fire room after everyone in theroom has been evaluated. In this way, smoke can be contained in the fireroom and its propagation can be slowed down. We need to check the fireroom conditions continuously and we may open the doors of the fire room
to release heat so that the flashover conditions in the fire room can be built
up. It means that human intervention to the control system is needed. The
HVAC controllers can supply fresh air to assist evacuation and can beturned off if there is no person in the area. The saved power can be
redirected to the needed place. Smoke exhaust fan controllers could also becontrolled to maximize the capability of smoke exhaust in the needed areas.
The modified smoke control procedure can adjust control strategies of doors,
smoke exhaust and HVAC based on real-time information of sensors andvideos. In this paper, we will discuss the benefit obtained from such control
procedure.

Fig. 2 Modified Smoke Control Procedure
3.2 Simulation Fire Scenarios Design

To study modified smoke control procedure, different fire scenarios are
setup. Fire location is shown in Fig. 1. Fire source is considered as propane
gas combustor and lies in the right top with the area of about 4 m2. The
sprinklers are functional. The maximum fire power is set to be 10MW andfire develops to the maximum fire power at 300s.
4. Simulation Results

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CFAST from NIST is selected to study the smoke control parameters.
Smoke propagation will be simulated with door controller and without door
controller, with HVAC and without HVAC and with traditional smoke
control procedure and with modified smoke control procedure.
4.1 Simulation with Door Controller and without Door Controller

In this case, door of fire room (door1 in Fig.1) will be closed when no
person is detected in the room to prevent smoke propagation in corridors
through door 1, as shown in Fig. 1. Evacuation time is assumed 200s. Door
1 is closed when no person is detected in fire room. Door 2 and 3 (rooms
without fire) are always open. Smoke exhaust vents are always open. HVAC
vents are always closed.
800
700

No Door Controller
Use Door controller

Time（s）

600
500
400
300
200
100
0
Corridor 1

Corridor 2

Corridor 3

LocationFig.3 Time of Smoke Height reach to 1.8m comparison
Time for smoke height reaching 1.8m in corridor1 with door controller andwithout door controller is shown as Fig 3. It is proved that closing door offire room can prevent smoke propagation in corridors through door 1.
8.8%~40% time is increased to help people evacuation. In corridors smokeheight can be delayed effectively.
4.2 Simulation with HVAC and without HVAC

In this case, HVAC in rooms without fire will be turned on to prevent
smoke moves down and assist evacuation of occupants. HVAC vents inroom 2 and room 3 (rooms without fire) are always opened. Smoke exhaust
vents are always open. Door 1 (room with fire) remains open. Doors 2 and 3
are always open.

Your Paper Title

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October 2009, Incheon, Korea

Fig. 4 Concentrations of Carbon Monoxide

Fig.5 Concentrations of Carbon Dioxide
HVAC system in room 2 and room 3 are turned on and toxic and harmful
gas concentration in rooms can be reduced by the fresh air. Carbon
monoxide concentration curve is shown in Fig.4 and carbon dioxide
concentration curve is shown in Fig.5. It is evident that concentration of
upper layer carbon monoxide and carbon dioxide is reduced to about 30 %by fresh air.
4.3 Simulation with Tradition and Modified Smoke Control Procedures

In this case fire scenarios are designed according to modified smoke control
system. It is assumed that time needed for evacuation from fire room, room
2 and room 3 are 200s, 150s, 200s, respectively. Door controller in fireroom is turned on and door 1(room with fire) is closed after 200s.HVAC
vents in room 2 and room 3 (rooms without fire) are opened during
evacuation and closed after 150s and 200s. Smoke exhaust vents are always
open.

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Fig.6 Smoke Height in rooms and corridors at 300s, 600s, 800s
Smoke height in rooms and corridors at 300s, 600s, and 800s are shown in
Fig.6. It is clear that door controller of fire room can prevent smoke
propagation through fire room door and HVAC can improve air condition in
the rooms without fire. In rooms smoke height has almost no change inmodified strategy comparing with traditional control strategy and in
corridors smoke descends more slowly using door and HVAC operation. It
is shown that smoke height is reduced by about 2% and in corridors smokeheight delay rate is about 10% from Fig.6.

Fig.7Carbon Monoxide Concentrations in rooms and corridors at 300s,
600s, 800s
Concentrations of upper layer carbon monoxide and carbon dioxide areshown in Fig.7 and Fig.8. Concentrations of toxic gas in corridors androoms can be reduced and air condition can be improved for humanevacuation. It is shown that in concentration of upper layer carbon
monoxide and carbon dioxide is reduced to 30%~40% and in corridors
concentration of upper layer carbon monoxide and carbon dioxide is
reduced to 20% from Fig.7and Fig.8.

Your Paper Title

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October 2009, Incheon, Korea

Fig.8 Carbon Dioxide Concentrations in rooms and corridors at 300 s, 600
s, 800 s
5. CONCLUSIONS

The intelligent smoke control procedure using HVAC operation and door
control strategy can slow down smoke propagation in rooms and corridors
by combined action of door controller and HVAC controller using sensor
readings.
(1) With only door controller, closing door of fire room can prevent smoke
propagation in corridors through door 1. 8.8%~40% time is increased tohelp people evacuation.
(2) With only door controller, concentration of upper layer carbon monoxide
and carbon dioxide is reduced to 30 % rate by fresh air. And 10% time fortoxic gas reach to safety limits can be improved.
(3) The intelligent smoke control procedure can prevent smoke propagation
through door 1 and in corridors smoke height delay rate is about 10%.
(4) The intelligent smoke control procedure can reduce concentration ofcarbon monoxide and carbon dioxide in rooms by about 30-40% and it incorridors is reduced by about 10%.
ACKNOWLEDGEMENT

This research is supported by National Nature Science Foundation of China(Grant No. 70833003).
REFERENCES
W.Z. Black, George W and Woodruff , 2008. Smoke movement in elevator
shafts during a high-rise structural fire, Fire Safety Journal,3, 1~15
Olivier Vauquelin, 2007. Experimental simulations of fire-induced smoke
control in tunnels using an ‘‘air–helium reduced scale model’’: Principle,
limitations, results and future, Tunnelling and Underground SpaceTechnology,23,171~178

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L.H. H, J.W. Zhou, R. Huo, W. Peng and H.B, 2007. Wang, Confinement offire-induced smoke and carbon monoxide transportation by air curtain inchannels, 12, 327~334
Yuan Shusheng and Zhang Jian, 2007. Large eddy simulations of fire smoke
flow and control in an underground shopping mall, Journal of University of
Science and Technology of China, 37, 61-69
Jong-Yoon Kim and Sung-Wook Yoon, 2006. A study on the smoke
control characteristic of the longitudinally ventilated tunnel fire using PIV ,Tunnelling and Underground Space Technology, 21, 302
Dong-Ho Rie, Myung-Whan Hwang and Seong-Jung Kim, 2006. A study of
optimal vent mode for the smoke control of subway station fire, Tunnellingand Underground Space Technology, 21, 300-301
Su M D, 1990. Algebraic modeling of large eddy simulation and its
application, Science in China (Series A) , 33, 185～195
McGrattan K B, 2001.Computational fluid dynamics and fire modelling ,National Institute of Standards and Technology , 21, l～50
Woodburn PJ and Britter RE, 1996. CFD simulation of a tunnel - Part 1.
Fire Safety, 26, 35-62
Woodburn PJ and Britter RE, 1996. CFD simulation of a tunnel - Part 2.
Fire Safety, 26, 63-90
XU Liang, ZHAN G Heping , YANG Yun , et al, 2004.Preparatory study on
fire design in performance-based design. Fire Science and Technology, 23,
129~132.
J.Liu and X.Y.Lu, 2002. Application of Large Eddy Simulation to Smoke
Movement, Fire Safety Science, 2, 5～15
McGrattan K and Forney G, 2004.Fire Dynamics Simulator (Version 4),
Technical Reference Guide [R]. NIST Special Publication, 2, 10~18.
D.Madrzykowski and W.D. Walton ,2007.Cook County Administration
Building Fir 69 West Washington, Chicago, Illinois, October 17, 2003:
Heat Release Rate Experiments and FDS Simulations, NIST Special
Publication SP-1021,7
Z. Dong Chen and David Yung, 2005.Numerical Study of Two Air Intake
Strategies for a New Fire Laboratory, Fire Protection Engineering, 17,
27~41Your Paper Title

691

PARALLEL SESSION 11

EVALUATION ON PERFORMANCEDEGRADATION OF DETERIORATEDCIVIL INFRASTRUCTURE
HIROSHI YOKOTA
Graduate School of Engineering, Hokkaido University, Japan
yokota@eng.hokudai.ac.jp
YOSHITAKA KATO, REIKO KUWANO, TAKAHIRO ENDO
International Center for Urban Safety Engineering
IIS, The University of Tokyo, JapanEMA KATO
Geotechnical and Structural Engineering Department
Port and Airport Research Institute, Japan

ABSTRACTTo realize the performance-based maintenance for civil infrastructure,
it is necessary to evaluate structural performance by applying various
measuring techniques. At present, however, established techniques are
unfortunately not available that can collect accurate and quantified
information how the structural performance is degraded. In particular, acomprehensive evaluation of an entire structure from the ground to thesuperstructure is rather difficult.
The ICUS, International Center for Urban Safety Engineering, of theTokyo University set up Research Committee 62 in April 2008 to address
the challenge of performance evaluation of an entire structure fromstructure to ground. This paper introduces the activity of this researchcommittee and presents the outlines of the outputs during the first year. The
first year of our activity focused on the review of current available
measuring techniques for concrete or earth structures. Also the committee
started to seek the future advancement of each technique as well as themerger of several techniques to make it possible to apply for a groundconcrete structure.

1. INTRODUCTION
Civil infrastructure has been built with several kinds of structural types andmaterials including concrete, earth materials, steel, plastics, etc. Those
structures are well designed at first to have sufficient performance beyond
the requirements. During the design service life, the initially provided
performance will be lost gradually due to aging (material deterioration),
obsolete functions, change in use, etc. To keep structural performance over693

October 2009, Incheon, Korea

the requirements, performance-based maintenance has to be introduced. To
quantify structural performance that the structure possesses at the time ofassessment, measurement techniques including NDT (non-destructive
testing) have been applied, but most of them are limited to use only forquantifying physical response to corresponding structural performance. In
particular, overall structural performance from the ground to thesuperstructure is very difficult to quantify by using current NDT techniques
available in the market.
To meet this situation, the ICUS (International Center for Urban Safety
Engineering) of the IIS (Institute of Industrial Science) in The University ofTokyo set up the research committee “Evaluation Technology of Degraded
Performance of Civil Infrastructure due to Aging” which started its activity
in April 2008. This research committee consists of two working groups:
WG1-performance evaluation of structures and WG2-performance
evaluation of ground and earth structures. This paper presents the interim
report of the activity of this research committee during the first half of its
activity.

2. PERFORMANCE EVALUATION
The time-dependent change in structural performance can be understood asshown in Figure 1. A civil structure is designed according to relevant design
standards and specifications to have adequate safety and serviceability.
However, the safety of structure is not fully simulated its degradation due toexternal actions including environmental action. To realize performancebased maintenance, structural performance should be quantified accurately
at any time during the service life of structure. The WG1 has investigatedthe methodology to quantify the structural performance possessed andrequired taking into account material deterioration.
Performance
InitialChange inperformance

Re‐definition of
performancepossessed
Quantificationof performance

Required level
Re‐definition of
performancerequiredTime
Start inservice
Condition of structure→ Quantification → Verification
Load and environmental action

Figure 1: Concept of performance evaluation.

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New Technologies for Urban Safety of Mega Cities in Asia

2.1

Scope

The WG1 has focused on the following targets for performance
evaluation:(a) Cause of deterioration: Time-dependent deterioration caused byenvironmental action such as chloride-induced deterioration, carbonation,etc. Change in external load over time such as hydro pressure, earth pressure,etc. excluding seismic action.
(b) Structural performance: Serviceability (deflection, stress, etc.) andsafety (load-carrying capacity, deflection, etc.)(c) Structural type: Concrete structures buried under the ground
2.2 Index for Performance Evaluation
Example analyses have been carried out to quantify performancedegradation of the ground and earth structures by referring to publishedpapers and reports. The references lists can be obtained from the ICUS
Report, 2009.
2.2.1 Water channel subjected to impulsive railway loads
Damages of a reinforced concrete duct subjected to impulsive railway
loads and water flows have been investigated by vibration property underirregular vibration and AE measurement. The damaged area that can bevisibly observed showed a decrease in natural frequency compared to that of
the sound area. There have been some correlations between AE property
and vibration property. Therefore, the AE property may become an index
for performance quantification.
2.2.2 RC sewage pipe
Chemical deterioration due to hydrogen sulfide was focused on for areinforced concrete sewage pipe. Exposure tests of epoxy covered
specimens in a sewage pipe have been carried out to measure thepenetration depth of sulfur ion into epoxy coating layer and change inweight of the specimen. The applicability of the square-root t (t: exposuretime) method was discussed.
2.2.3 Irrigation canal pipe
Time-dependent change in organic soil layer was discussed. Water
leakage from the pipe has often been observed in the area where thethickness of the organic soil layer was changed. Long term settlement of thelayer might have caused differential settlement of the pipe resulting in
discontinuity of the joints, which resulted in the loss in serviceability(function) of the structure.
2.2.4 Steel base plate of oil tank
Corrosion of steel base plate of oil tank degrades the safety and causes
oil leakage. The relationship between corrosion risk and AE activity has
been verified by field measurements. It was concluded that AE detects
peeling of corrosion products and minute cracks of steel.

Evaluation on Performance Degradation Of Deteriorated Civil Infrastructure695

October 2009, Incheon, Korea

2.2.5 Cave and loosen part behind quay wall and sea walls
Hydro pressure variation due to wave action and damage of joints andprotective sheet produce sucking of backfilling materials, resulting in caveand cave-in of the ground behind the structure. The specific electricalresistance of the ground was measured by the frequency domain electromagnetic induction (FDEM) technique. Subsurface properties and features
were able to be deduced by FDEM. Using the relationship between relative
density of the ground and specific electrical resistance, loosened part can bedetected.
2.2.6 Deterioration of concrete
The following quantified indices may be applicable for performance
evaluation of concrete structures themselves:(a) Carbonation: carbonation depth, cross-sectional loss of embedded
steel reinforcement due to corrosion, and width of corrosion crack(b) Chloride-induced deterioration: chloride ion concentration, crosssectional loss of embedded steel reinforcement, and width of corrosion
crack(c) Frost damage: frost damage depth and cross-sectional loss ofembedded steel reinforcement(d) Chemical deterioration: penetration depth of deterioration factor,
carbonation depth, cross-sectional loss of embedded steel reinforcement(e) Alkali-silicate reaction: remaining expansion and crack property(f) Fatigue failure: crack density, deflection, cumulative damage, andcracks in steel(g) Abrasion: abrasion depth and abrasion rate
2.3 Prediction of Performance Degradation
Technologies for evaluation of present structural performance and its
future prediction can be categorized by the following methods:(a) Direct evaluationa-1) Grading system based on inspectionsa-2) Performance degradation curves based on inspection resultsa-3) Comprehensive evaluation including deterioration causes andinterventions based on inspection resultsa-4) Monitoring and analysis(b) Long term exposure tests in natural environment(c) Laboratory tests(d) Numerical simulation
For actual concrete structures, the grading method (a-1) or the
performance degradation curve based on the inspected grades (a-2) haveoften used as a practical approach. The other approaches have not reached
the practically applicable stages.
2.4 Future Prospect
The results of inspections are utilized for the grading system and thedegradation curves. This approach is reasonable for practical maintenance

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work, but some deficiencies in accuracy and in reflecting deterioration
mechanism.
For detailed evaluation of performance, it is efficient that currently
available design methods are applied including the determination of partial
safety factors. For the evaluation, it is important to link the deteriorationindex and the input parameters for structural design with high accuracy. For
taking the deterioration mechanism approach, the process from external
factor to internal factor to performance degradation should be made clear
and standard investigation method should be provided.

3. PERFORMANCE QUANTIFICATION TECHNIQUE
3.1 Scope
When picking up a bridge, the interaction between the main structure
and the ground locates in its foundation. There are several kinds offoundation types such as spread footing and pile foundation, and all ofwhich are very difficult to inspect directly. Moreover, abutment and pier are
sometimes located in waterfront or in a river, in which they are exposed tovery severe environments. Consequently, deterioration often occurs due tochloride ion, alkali-silicate reaction, frost attack, etc. In the pier of bridge,
sliding due to scouring and deformation due to excessive earth pressure may
occur, which are different types of deterioration from those in the main
structure of bridge.
3.2 Investigation Technique
Investigation techniques for underground structures and earth
structures are collected. Since underground structures are not visible directly,
techniques to measure the position, length, etc. are focused on. For earth
structures, techniques to investigate soil properties are mentioned.
For underground structures:(a) Borehole radar- spacing of piles and conditions of undergroundstructures (pile and foundation)(b) Underground radar search- buried objects, cave, and loosenedarea(c) Color imaging sonar- scouring(d) Magnetic logging- searching metal
For the ground:
Velocity logging- physical properties of ground3.3 Damage detection in structure
To detect damages of underground structures, the following
techniques are available:(a) Integrity test- cracks and defects in pile and length of pile(b) Borehole camera- discontinuity and/or cracked areas in the hole(c) Convergence meter- displacement(d) Total station- shape and geometry

Evaluation on Performance Degradation Of Deteriorated Civil Infrastructure697

October 2009, Incheon, Korea(d) Impulsive elastic wave- inner defects(e) GPS- 3-D position
The most reliable method for detecting damages in a pile foundationis the visual inspection but it limited to the pile head area only. In somecases for buried parts of pile, the integrity test has been applied for damage
detection, while minor damages may not be found. Borehole camera has
also been applied as directly detective method, but quantified evaluationsuch as crack width is difficult.
The effectiveness of AE technique has been confirmed for damage
detection of pile through laboratory and field tests. As NDT, elastic stresswaves are trying to apply, where change in propagation property at thediscontinuity points is utilized. This method is possible to detect minutecracks.
3.4 Monitoring
For continuous monitoring, the following are available:(a) Optical fiber sensor(b) Conductive paint
Monitoring has been sometime applied for damage and deformation
detection in a pile foundation, in which sensors are pre-set. An optical fiber
sensor is currently most popular for this purpose including SOFO type,OTDR type, B-OTDR type and their combinations. Instead of optical fiber,
carbon fiber, as a trial, has been installed to measure strain and crack
initiation. Other newly invented sensors are available. Besides them,piezoelectric device, permeable device with porous materials, currentcarrying capsule, etc. have been in the process of practical realization formonitoring purposes.

4. INTEGRATION OF STRUCTURE AND GROUND
Performance degradation of concrete retaining walls and sea walls that are
greatly affected by performance of the ground has been discussed from theconcrete structures points of view.
4.1 Example Analysis
Reinforced concrete L-shaped retaining wall fell down due toexcessive seismic action. Another example is collapse of a gravity typeretaining wall due to erosion. These two examples have been fully
investigated by means of structural analysis and numerical simulations.
4.2 Fault tree
The failure mechanism of a retaining wall and a sea wall is very
complex due to the interaction of various elements including ground andstructural components. Using a fault tree analysis is extremely useful as away to understand possible failure mechanisms.

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A sea wall and a revetment are typical structures with the principal
function of preventing overtopping and flooding due to storm surges andwaves. An overview of the common modes of failure of sea walls andrevetments has been analyzed as a fault tree (JSCE, 2000). The failuremodes of sea walls and revetments include the following:(1) Sea bed scours and toe erosion in front of the structures caused
by wave action(2) Subsequent undermining of rubble foundation and piping of corematerial; dislodging of slab elements and displacement of crests and rearside armor due to wave action; and subsequent wash out of core materials.
(3) Damage to parapets due to wave action; subsequent collapse of
crests of sea walls.
Deterioration of seawalls and revetments progresses as follows:(1) Occurrence of small cracks and chipping in elements of thestructure due to environmental action.
(2) In case of soft seabed soils, the weight of the structure causes
settlement due to progressive consolidation; subsequent opening of structure
joints due to differential settlement and piping of fine materials fromstructure.
4.3 Performance degradation
Analysis of examples show that damages occurring in a retaining
wall and a sea wall may be caused by the following performancedegradation of the ground: excavation, embankment, uncertainty of soil
properties, weathering, excessive seismic action, insufficient drainage,
residual water level rise, and chemical deterioration. Those are not fully
quantified the extent of performance degradation, but affect the overall
performance of structure. When some of those occur, countermeasures aretaken particularly for the ground. Therefore, maintenance work focusing on
the interaction between concrete and the ground should be required for thesetypes of structure. For this purpose, periodic inspection and monitoring areof use for early detection of deformation.

5. PERFORMANCE EVALUATION OF EARTH STRUCTURESFor understanding the performance degradation of earth structures, example
analyses have been made in the first half year. The following examples havebeen collected:(a) Failure and settlement of embankment, hollowing inside
embankment, and cave in of sand beach(b) Settlement of natural ground and reclaimed land(c) Scouring of pier foundation(d) Cave in of road and settlement of slope shoulder(e) Failure of slope(f) Deformation of tunnel, collapse of water supplying tunnel(g) Water leakage from tunnel lining(h) Carbonation of concrete foundation in acid ground and alkali
silicate reaction

Evaluation on Performance Degradation Of Deteriorated Civil Infrastructure699

October 2009, Incheon, Korea(i) Leaching of calcium ion from the cement stabilized groundThe change in performance may be detected as the following
indices:(a) Hollowing and cave in of seawall, embankment: distribution of
infiltration contour, washout of fine soil particles(b) Stability of structure: crack in structure, strength reduction(c) Cave in of road: outflow of soil into damaged part, hollowing,
extent of loosened part, and increase in void ratio(d) Scouring of foundation: outflow of soil(e) Failure of ground, slope, retaining structure: deformation ofground(f) Collapse of tunnel: weathering and erosion

6. CONCLUDING REMARKS
Following the first year activity, the committee will be focusing on muchdetailed analysis for performance evaluation of the structure-ground system.
During this, field measurements including monitoring will be applied to
discuss the availability and accuracy. The members of the committee
meeting are grateful for further supports by practical engineers.
The authors would like to extend their appreciation to all the researchcommittee members for their activities.

REFERENCES
International Center for Urban Safety Engineering, 2009. Interim Report,
Research Committee on Evaluation Technology of Degraded Performanceof Civil Infrastructure due to Aging. ICUS Committee Report 2009-001, inJapanese.
Japan Society of Civil Engineers, 2000. Design Manual for Coastal
Facilities, Maruzen.

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REPORT OF NON DESTRUCTIVETESTING FOR AN AIRPORT RUNWAY AND
BRIDGE ASPFALT PAVEMENT BY USINGINFRARED CAMERANOBORU SATO
Sankyo Co. Ltd, Tokyo, Japannsato@sankyo-net.co.jp

ABSTRACTAsphalting is essential to an infrastructure as a freeway and airport
runway. However, life cycle of asphalting is different from a concrete
structure. It’s short, and degradation and damage of pavement materials.
Detaching and dead water phenomenon arise at asphalt on the bridge, andblistering occurs at airport runway. This time, We report on damage ofasphalting on a bridge and the detection method of "blistering" which
occurs at airport runway.

1. Detection which damage of asphalting on bridge
Damages of asphalting on bridge are as follows.
①
Crack
②
Rut
③
Detaching between Surface layer and basis layer④
Dead water under the asphalting
A rut investigation with a laser and a crack investigation with a video
camera were main method for conventional maintenance of bridgeasphalting. Core sampling is being performed in local way and asphalt isbeing checked adherently These were investigation of point and line, andcase with plane-like investigation detaching and information on dead wateris very few.
On the other hand, it's possible to be in creating an image ofdistribution of temperature in the pavement surface and presume damage
inside the pavement by infrared thermography.
We show an example of a pavement investigation of steel box girder
bridgeDetaching between the Surface layer and the basis layer was presumed
by the temperature of the pavement surface. And then, dead water waspresumed from the low surface temperature. After the part detected byinfrared image was cut, inter layer peeling and the dead water under the
pavement were found.

701

October 2009, Incheon, Korea

cold area

The pavement surface temp.
℃

hot area

Damage or Detaching
Surfacebasis layer
Steel Deck
Dead water
Closed rib

Closed rib

Figure 1: The Section of the bridge and the pavement surface
temperature
Joining board（cold area）

cold area Ａ

hotr

The shoulder of the roadcold area

Ｂ

Line markseeped water
It broke between the Surface layer
and the basis layer
cold area

hot area

Figure 2: As a result of the distructive test.

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2. DETECTION WHICH DAMAGE OF ASPHALTING ON THE
RUNWAY.
On July 2, 2000, asphalting coiled around a tire at the time of a planelanding in one of airport in Japan. And then, asphalting came off andscattered. Therefore it caused a delay in the service of the plane.
The cause of the accident are high temperature in summer, andblistering that produced sealing up on the surface layer dense water of theasphalting inside. Such blistering phenomenon occurs at a runway in allover the world.
Many engineers find blistering with a hammer in the midnight now.
However, a correct test result is not provided. Because to be tired fromwork of the midnight when paving do not be smooth in the airport runway.
And then, it’s very difficult to record the location of detected
blistering correctly in the vast runway. We suggested infrared thermographythat method which test result was full of objectivity and could record acorrect position.

Tapping sound check by a hammer

Grooving on the pavement

2.1 Measurement principle
The infrared thermography method can find blistering fromtemperature distribution of the pavement surface.
Asphalting is heated up by sunshine in the daytime, and the heat movein the ground deeply.
In the night , and the temperature fall, heat in the pavement surface
also falls. But the heat which heated up in the daytime, in the ground, it
depends deeply and is being transmitted to the asphalt surface. But for an
air layer of blistering to interrupt spread of heat from the ground, the part
blistering generates becomes cold.
The above explains the part of blistering generates has low asphalting
surface temperature and a good part indicates high temperature. But, thepicture is reversed by daytime measurement.

Report of Non Destructive Testing For An Airport Runway And Bridge Asphalt Pavement By Using Infrared
Camera703

October 2009, Incheon, Korea

Heat is coming up from thedblistering

surface layerbaselFigure 3: .Surface temperature in the nightShow a section of the runway asphalt pavement in figure 4.

≒700mmhigh density asphalt

Macrogrits asphalt
high density asphalt
Macrogrits asphalt

Concrete on the bulk

Figure 4: Runway section（the number of asphalt layers）
2.2 Method for measurement
At first, marking in square of 10m on the runway to grasp
positioning information of the taken picture
An infrared camera is set in the high location of the vehicle for highlift work, and a picture is being recorded while running.After analyzing therespective pictures, a picture is connected and a picture in the whole runway
is made. The part which indicated low temperature on the picture isblistering on above
Figure-5 shows the measurement situation with using the maintenancevehicle.
Figure-6 shows picture of blistering detected by an infrared camera.
These results shows that blistering appears clearly at low temperature
We get such data at many runways, therefore blistering of about 10
cm in depth is detected as a result of core sampling.

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There are few record of an investigation by infrared camera, but we
expect that the investigation spreads at runways more.

Engineer＆System on the deckIR camera＆ engineers on the deck
Speed :3-5km/h

Figure 5: The measurement situation

Mark of oil

blistering

blistering
Mark of oil

⊿ｔ

1 20

⊿ｔ＝1 83～

Figure 6: picture of blistering detected by an infrared camera
Report of Non Destructive Testing For An Airport Runway And Bridge Asphalt Pavement By Using Infrared
Camera705

October 2009, Incheon, Korea

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RECOVERY MECHANISM OF FIREDAMAGED HIGH-STRENGTH MORTARYOSHITAKA KATO
ICUS, Institute of Industrial Science, The University of Tokyo
katoyosh@iis.u-tokyo.ac.jp
MICHAEL HENRY
Department of Civil Engineering, The University of Tokyomwhenry@iis.u-tokyo.ac.jp
MASAMITSU SUZUKI
Department of Architecture and Civil Engineering,
Shibaura Institute of Technology
m-suzuki@iis.u-tokyo.ac.jp

ABSTRACTThe performance of concrete deteriorates when exposed to fire, but
may be recovered by re-curing the concrete in water. A repair method for
fire-damaged concrete which utilizes re-curing could reduce waste
generation and resource consumption by restoring the performance of thedamaged material. However, the capability and mechanisms for such a
repair method are not clear. Experiments were conducted to resolve therecovery mechanism under by examining both the physical and chemical
perspectives. It was found that durability characteristics could be fully
recovered but strength could only recover to 80% of pre-fire levels.
Mechanical deterioration was due to the occurrence of surface cracks andthe coarsening of the pore structure, which were caused by thermal
decomposition, and recovery was due to pore structure growth and crack
self-healing. The growth observed in the pore structure could be attributed
to the re-hydration and increase of hydration products which were
dehydrated during heating. However, the re-hydrated pore structure isbelieved to be weaker than the original structure, thus resulting in lower
strength even after re-curing.

1. INTRODUCTION
Concrete exposed to high temperatures undergoes a reduction in
performance, such as decreased load-carrying capacity and durability. In
order to restore these properties repairs should be conducted, which
typically involve the removal of damaged areas and the casting of apatching material (Tovey, 1986). Unfortunately, the removal operations
require intense labor and produce waste which must be disposed of. Past
research has found that re-curing fire-damaged concrete in water can restore
strength and durability (Crook & Murray, 1970; Sarshar & Khoury, 1993;
Poon et al., 2001). A repair method which utilizes re-curing could
potentially replace or reduce the extent of labor-intensive operations, saving707

October 2009, Incheon, South Korea

energy and labor costs and reducing waste generation and resource
consumption.
For re-curing to be realized as a repair method, the re-curing
mechanism and capability should be understood. In a previous research by
the authors on high-strength mortar damaged by fire, loss and recovery ofstrength and durability were attributed to changes in porosity and cracking
caused by different cooling and re-curing conditions (Kato et al., 2008).
However, the scope of the previous research did not include a chemical
analysis component. This paper builds upon that previous research byconsidering the loss and recovery of strength and durability in terms of thechanges in chemical composition, and combines the chemical changes withthe observed changes in porosity and cracking to propose a recovery
mechanism for fire-damaged high-strength cement mortar.

2. EXPERIMENTAL PROGRAM
2.1 Materials and specimens
High-strength cement mortar was prepared from water (W), Type 1
Portland cement (C), Fujigawa river sand (S), and air-entraining (AE) andsuper plasticizer (SP) admixtures, with a target 28-day compressive strengthof 100 MPa. Complete mix proportions are given in Table 1. After mixing,
cylinder specimens (5Ø×10cm) were cast and cured in the molds for 24hours, then removed and placed in water curing at 20ºC for 13 days before
being moved to air curing at 20ºC and 60% relative humidity (RH).
Table 1: Cement mortar mix proportions.
(by mass)(kg/m3)(%C by mass)
W/C
S/C
W
C
S
AE
SP
0.3
1.8
230
767
1380
0.4
1.5
2.2 Fire exposure
Fire exposure was conducted 28 days from casting using an electric
furnace. As this furnace does not have a control mechanism for the rate ofheat increase, the furnace was preheated to the target temperature before
beginning specimen exposure. Based upon a trial series of tests, theexposure condition was set at 550ºC for 2 hours.
2.3 Re-curing regimes
After removal from heating, specimens were placed in one of three recuring regimes, as shown in Table 2. These re-curing regimes consisted of acooling period and re-curing period, where the cooling period refers to thefirst hour after removal, and the re-curing period is the period from cooling

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until testing. Environmental conditions were 20ºC and 60% RH for “air”
exposure and 20ºC and total water submersion for “water” exposure.

RegimeAir
Water
Air-water

Table 2: Re-curing regimes.
Cooling period
Removal – 1 hour
Air
Water
Air

Re-curing period
1 hour – 28 days
Air
Water
Water

2.4 Strength and durability tests
Compressive strength was measured under the unstressed residual
condition. Three cylinders were tested at each data point and the averagevalues are reported.
For air permeability, cement mortar cylinders were dried at 40ºC andchecked by monitoring the weight change, and then air permeability
specimens were cut 4 centimeters from the top of the cylinder. The
specimens were then set into an air permeability test machine and thevolume of flowing air was measured under steady state conditions. Two
cylinders were tested at each data point and the average values are reported.
Compressive strength and air permeability tests were conducted
before heating, 1 hour after heating (air and water cooling), and after 3 and28 days (air, water, and air-water re-curing).
The accelerated carbonation test began after 28 days of re-curing (air,water, and air-water). Test conditions were 20ºC±2ºC, 60%±5% RH, and
5%±0.2% CO2 concentration, and the carbonation depth was measured at 1,
4, and 8 weeks after 4 weeks of re-curing. Results are given in terms of the
carbonation rate for specimens which were not exposed to fire, as well as
for specimens in the three re-curing regimes.
2.5 Micro- and macrostructure observation
The cement paste microstructure was characterized utilizing mercury
intrusion porosimetry (MIP). MIP specimens, approximately 5 mm in size,
were taken from compressive strength cylinders after testing. These
specimens were submerged in acetone to stop the hydration reaction andthen dried using a D-dry vacuum pump. Testing for MIP specimens was
conducted at the same time points and under the same exposure conditions
as the compressive and air permeability tests.
In order to measure the macrostructure changes, the cracking patternand crack recovery under different re-curing conditions was observed using
an epoxy injection procedure (Iwaki et al. 2004). After re-curing, afluorescent epoxy was injected via vacuum pressure. This process can injectepoxy into cracks as small as 6 micrometers, and the hardening of the epoxy

Recovery mechanism of fire-damaged high-strength mortar

709

October 2009, Incheon, South Korea

helps to prevent secondary defects from forming. After epoxy injection,cylinders were cut in section 4 centimeters from the top, placed underultraviolet (black) light, and the dispersion of the epoxy was recorded byphotograph. Only air (7 days) and water re-cured (1 hour and 7 days)
specimens were observed.
2.6 Chemical analyses
Three chemical compounds were investigated; calcium hydroxide(Ca(OH)2), calcium oxide or lime (CaO), and calcium carbonate (CaCO3).
The two primary cement hydration products are C-S-H and Ca(OH)2, but it
is difficult to measure C-S-H so this research focused on Ca(OH)2. CaO is
produced by the thermal decomposition of Ca(OH)2, and CaCO3 is producedby the carbonation of CaO and Ca(OH)2. Samples for chemical tests weretaken 10 millimeters from the surface in the upper half of cylinder
specimens, and fine aggregates were removed to produce cement powder.
The crystalline structure was observed using X-ray diffraction (XRD).
Experiments were conducted using CuKα testing conditions with a range of
2θ = 5 - 60º, 0.02 step scan, and scanning speed of 0.5º per minute. The
diffraction profile was acquired using JADE (Rigaku), and qualitative
analysis of the diffraction profile was conducted by PDF (ICDD) andtargeted the diffraction peaks of CA(OH)2, CaCO3, and CaO. Results are
given in terms of the peak number ratio, which describes the change in the
crystalline structure relative to the initial condition.
Evaluation of the hydration progress was conducted using thermogravimetric and differential thermal analysis (TG-DTA). A heating speed of
10ºC per minute and a maximum temperature of 1000ºC in a nitrogen gas
atmosphere were set as the measurement conditions. Two properties were
calculated: the amount of chemically-bound water, which was measured by
the ignition loss between 105ºC and 1000ºC, and the amount of Ca(OH)2,
which was calculated by the mass change which occurred around 450ºC.

3. PREVIOUS RESULTS
In previous research works by the authors, the recovery of strength (Henryet al., 2008) and durability (Kato et al., 2008) were investigated under
different re-curing conditions. These results are briefly introduced andsummarized in the following section.
3.1 Compressive strength
Compressive strength results and the relative change in strength due
to loss and recovery are given in Figure 1. Specimens which were cooled in
the air before water re-curing had the highest final compressive strength,
followed by water and air specimens. Although the air-water specimens had
the least strength loss, they also recovered less strength than water710

New Technologies for Urban Safety of Mega Cities in Asia

120

70

100

60

80
60
40
Air
Water
Air‐water

200% initial strength

Comp. strength (MPa)specimens, which underwent the largest strength loss but also the largest
strength recovery. Air specimens lost more strength than air-water
specimens, but recovered the least strength. From these results, it was
concluded that reducing the initial strength loss was more important thanincreased strength recovery for achieving higher final compressive strength.
Air
Water
Air‐water

50
40
30
20
10
0

Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Loss

RecoveryFigure 1 Compressive strength results (left) and loss/recovery (right)
3.2 Durability indicators

K (x10‐9 cm/sec)

1000

100

10

1

Air
Water
Air‐water
Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Carbonation rate (mm/√week)

Durability was evaluated using two indicators, the air permeability
coefficient and the carbonation rate, and the results are shown in Figure 2. It
can be seen that the re-curing period – from 1 hour to 28 days – had thelargest effect on the air permeability coefficient. During that period, the airpermeability of air specimens increased slightly and that of water and airwater specimens greatly decreased. However, the initial cooling period
affected the observed trend, as specimens first cooled in water had steadybut constant recovery, whereas specimens first cooled in air recovered more
quickly during the 1 hour to 3 day period with a slight increase over thefollowing period. The effect of water re-curing on carbonation was also
clearly seen, as only specimens re-cured in the air underwent carbonation.
The performance of specimens re-cured in the water was similar to that ofspecimens not exposed to fire.
0.6

0.52

0.5
0.4
0.3
0.2
0.1
0.0

0
Pre‐fire

Air

0

0

Water

Air‐water

Figure 2 Air permeability results (left) and carbonation rate (right)

3.3 Micro- and macro-structure

Recovery mechanism of fire-damaged high-strength mortar

711

October 2009, Incheon, South Korea

The porosity results are given in Figure 3. Similar to the airpermeability results, the largest effect can be seen during the re-curing
period from 1 hour to 28 days. Also similar to the air permeability results,
air specimens underwent little recovery, whereas the water and air-water
specimens recovered to levels similar to that prior to fire exposure. The
recovery behavior of water and air-water specimens followed the same trend,with water specimens recovering slightly more by 28 days.
0.30

Porosity (ml/ml)

0.25
0.20
0.15
0.10
Air
Water
Air‐water

0.05
0.00

Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Figure 3 Porosity results
Figure 4 shows specimen sections after epoxy injection under
exposure to black light. White areas show where the epoxy penetrated intocracks; dark areas are un-cracked. The specimen in the left image wasimmediately submerged in water after heat exposure; here, radial microcracks formed due to thermal shock. However, by 7 days these cracks had
healed under water exposure, as seen in the middle image. Air specimens
formed large surface cracks after 1 day of air re-curing, and these cracks did
not self-heal in the air re-curing condition, as shown in the right image.

Figure 4 Cracking pattern after 1 hour water cooling (left), 7 days water recuring (middle), and 7 days air re-curing (right)
3.4 Summary of previous results
From the previous results, it was concluded that the strength
behavior was affected both by changes in porosity and the formation ofmacro- and micro-cracks. The occurrence of cracking was used to explain
the difference in trends between the compressive strength and porosity. Recuring by air led to the formation of macro-cracks due to differential

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thermal shrinkage, reducing strength. Water submersion, while causing alarge reduction in strength due to thermal shock, also increased the strength
recovery behavior due to water absorption. As a result, micro-cracks formed
due to quenching were mostly healed within 7 days of water re-curing, andporosity recovered to pre-fire levels. Specimens cooled in the air before
water submersion absorbed less water due to the lower specimen
temperature at submersion, thus reducing recovery. Decrease in air
permeability under water and air-water re-curing conditions can be
attributed to crack healing and porosity recovery, whereas an increase in air
permeability for air specimens was caused by significant cracking and anincrease in porosity. Carbonation resistance was increased in water and airwater specimens by the decrease in porosity and the crack healing.
Although durability and porosity recovered to pre-fire levels after
water and air-water re-curing and crack self-healing was observed, pre-firecompressive strength was not achieved. In order to explain this disparity, aninvestigation on the changes in the chemical composition under variable recuring conditions was conducted.

4. CHEMICAL ANALYSIS RESULTS
4.1 XRDXRD results are shown in Figure 5. For these results, only the air
and air-water conditions are used in order to focus on the changes which
occurred from 1 hour to 28 days. It can be seen that fire exposure causes anincrease in the peak ratio of CaO and a decrease in the peak ratio for
Ca(OH)2. This is due to the thermal deterioration of Ca(OH)2 into CaO. For
air re-curing, the peak ratio for CaO decreases while that of CaCO3
increases; this can be attributed to the carbonation reaction of CaO with CO2,
which produces CaCO3. In the case of air-water conditions, however, thecrystalline structure appeared to return to conditions similar to that before
heating after only 3 days of water re-curing.
3.5

2.5

3.5
Ca(OH)2
CaO
CaCO3

2.0
1.5
1.0
0.5

3.0

Peak number ratio

Peak number ratio

Air
3.0

2.5

Air‐water

Ca(OH)2
CaO
CaCO3

2.0
1.5
1.0
0.5

0.0

0.0
Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Figure 5 Peak number ratio for air (left) and air-water (right) conditions
4.2 TG-DTA

Recovery mechanism of fire-damaged high-strength mortar

713

October 2009, Incheon, South Korea

120

120

100

100

80
60
40
20
0

Air
Air‐water
Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Amt. Ca(OH)2 ratio (%)

Chemically‐bound water ratio (%)

TG-DTA results for chemically-bound water and Ca(OH)2 areshown in Figure 6. After 28 days, air-water re-curing specimens have morechemically-bound water than before fire exposure. This is due to therehydration of CaO into Ca(OH)2, as well as the hydration of unhydrated
cement particules. In the air re-curing condition, the amount of chemicallybound water also increased, indicating that hydration was occurring evenunder low water supply conditions. The rehydration of CaO into Ca(OH)2 isagain seen in the increase in the amount of Ca(OH)2 between 1 hour and 28
days. However, in air re-curing conditions the amount of Ca(OH)2 decreases
after a slight increase, indicating that the Ca(OH)2 may be consumed incarbonation reaction with CO2, implying that the increase in chemicallybound water is due to the rehydration of C-S-H gel.

80
60
40
Air
Air‐water

200Before fire 1 hour 3 days re‐ 28 days
cooling
curing re‐curing

Figure 6 TG-DTA results for combined water (left) and Ca(OH)2 (right)

5. PROPOSED RECOVERY MECHANISM
In the chemical analyses, it was found that water re-curing of the air-water
specimens resulted in the development of a crystalline structure similar tothat prior to fire exposure, and that the amounts of chemically-bound waterand Ca(OH)2, one of the primary hydration products, were also similar tovolumes observed prior to fire exposure. Therefore, it still remains unclear
why compressive strength did not recover to pre-fire levels, even though theporosity of this series was similar to that prior to fire exposure at 28 days
and crack healing was observed under water re-curing conditions.
Since the results of the conducted chemical analyses cannot explain
the lack of compressive strength recovery, it is proposed that this is causedby the weakness of the healed cracks and the rehydrated cement pore
structure. Although the healing of cracks was both visually observed andsupported by the increase in durability under water re-curing conditions, nomechanical testing of the healed crack interface was conducted. It is
possible that there exist weaknesses or flaws in the newly-healed crack
interface that cannot be detected by visual observation, but still produce
improvement in durability. One reason may be imperfect cracking healing inthis area; another reason may be that the crystalline growth in the healed
crack is of a different or weaker composition than normal cement paste.

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The recovery of durability, through reduction of air permeability andcarbonation rate, can be clearly explained by the chemical analysis results.
The crystalline structure, after water re-curing, returned to a form similar tothat prior to heating, and the amount of hydration products was also similar
to pre-fire amounts. In addition, the observed porosity and crack recovery
also support the reduction of air permeability under water re-curingconditions. Furthermore, water re-curing reduced the amount of CaO
available for carbonation by reacting with water to form hydration product,
resulting in high carbonation resistance. In contrast, during air re-curing
CaO reacted with atmospheric CO2, increasing the crystalline growth of
CaCO3 and resulting in a much-higher carbonation rate. Finally, althoughporosity was slightly reduced due to carbonation and minor hydration fromatmospheric H2O, air permeability increased due to surface cracking.

6. CONCLUSION
The research conducted in this paper was intended to continue previous
research works by the authors by combining a chemical analysis component
with the previous mechanical evaluations and visual observations, with thegoal of explaining the recovery mechanism of fire-damaged high-strengthmortar. From the previous research works, it was unclear why compressive
strength did not fully recover under water re-curing, even when porosity
recovery and crack healing were observed.
After conducting chemical analyses and integrating those resultswith the previous observations, it was proposed that the strength of thehealed cracks and the rehydrated pore structure is weaker than that prior toheating, resulting in strength reduction even when crystalline structure,amount of hydration product, and porosity are found to recover to pre-firelevels and crack healing is observed. While water re-curing could not fully
recover compressive strength, durability characteristics such as air
permeability and carbonation rate were recovered to pre-fire levels. The
recovery of durability was primarily due to the crack self-healing and therehydration reaction, which reduced porosity and the availability of CaO for
carbonation. Since past research works have noted that concrete structures
which were exposed to fire often undergo severe damage due to carbonation,
the potential of water re-curing to reduce this damage is clear.
The purpose of any repair method for fire-damaged concrete is torestore three performance requirements: load-carrying capacity, durability,and fire-resistance. These research works have addressed the potential ofwater re-curing as a repair method by focusing on the first two requirements,
considering the case of high-strength mortar. However, the results may be
dependent on many of the experimental factors involved, such as mix
proportions, fire exposure variables, specimen size, and so forth. While amechanism has been proposed for the recovery of strength and durability,
based on the selected experiment conditions, it will be necessary for future

Recovery mechanism of fire-damaged high-strength mortar

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October 2009, Incheon, South Korea

research works to consider, to what extent, other conditions may have on the
explanation of the recovery mechanism and the potential for water re-curing
as a repair method.

REFERENCES
Crook, D.N. and Murray, M.J., 1970. Regain of strength and firing of
concrete. Magazine of Concrete Research, 22(72), 149-154.
Henry, M., Ahn, T.H., Kato, Y., and Kishi, T., 2008. Development of adamage-recovery relationship based on variable re-curing of fire-damaged
high-strength mortar. Proceedings of the First International Symposium on
Life-Cycle Civil Engineering, Varenna, Italy, 165-170.
Iwaki, K., Kato, J., Hirama, A., and Shiotani, T., 2004. Micro-structural
evaluation of concrete damaged by acid attack using optical microscopy.
Proceedings of the Japan Concrete Institute, 26(1), 999-1004. (in Japanese)
Kato, Y., Henry, M., and Suzuki, M., 2008. Evaluation of re-curing for therecovery of fire-damaged high-strength mortar. Proceedings of theInternational Conference on Durability of Concrete Structures, Hangzhou,
China, 1310-1316.
Poon, C.S., Azhar, S., Anson, M., and Wong, Y.L., 2001. Strength anddurability recovery of fire-damaged concrete after post-fire-curing. Cement
and Concrete Research, 31, 1307-1318.
Sarshar, R. And Khoury, G.A., 1993. Material and environmental factors
influencing the compressive strength of unsealed cement paste and concrete
at high temperatures. Magazine of Concrete Research, 45(162), 51-61.
Tovey, A.K., 1986. Assessment and repair of fire-damaged concrete
structures – an update. ACI Special Publication 92: Evaluation and Repairof Fire Damage to Concrete, 47-62.

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EXPERIMENTAL STUDY OFULTRA HIGH STRENGTH CONCRETE
AND REACTIVE POWDER CONCRETESTRUCTURES UNDER BLAST LOADING
NA-HYUN YI1, SUNG-HWAN PARK1,
JANG-HO JAY KIM1, KEUN JOO BYUN1 and JONG -KWON CHOI2
1
Yonsei University, 262 Seongsanno,
Seodaemun-gu, Seoul 120-749, Korea{wwitch1, realpsh, jjhkim, byun}@yonsei.ac.kr
2
Hyundai Institute of Construction Technology, Mabuk-Ri,
Kuseong-Myun,Yongin City Kyungki-Do, 449-710, Korea
tunes1022@hdec.co.kr
ABSTRACT
Generally, concrete is known to have a relatively high blast resistancecompared to other construction materials. However, normal strength
concrete structures require higher strength to improve their resistanceagainst impact and blast loads. Therefore, a new material such as Ultra
High Strength Concrete (UHSC) and Reactive Powder Concrete (RPC) withhigh-energy absorption capacity and high resistance to damage is needed
for blast resistance design. In this study, the blast tests of UHSC and RPC
slabs with 1000×1000×150 mm specimens were carried out to investigate
their blast behavior. The applied blast load was generated by the detonationof 35lbs ANFO explosive charge at 1.5m standoff distance. From these tests,
it became clear that UHSC and RPC have better blast explosions resistancecompared to normal strength concrete. Based on this experiment test results,
design procedure of the RC structure is recommended.
1. INTRODUCTION
In recent years, there have been numerous explosion-related accidents due
to military and terrorist activities. Such incidents caused not only damages
to structures but also human casualties. Especially, in metropolitan areas
which are exposed to terror attack, these severe loading related accidents
can cause great human causalities, economical losses, and public
infrastructure destructions, and civilian structure collapses. To protect
structures and save human lives against explosion accidents, better
understanding of the explosion effect on structures is needed. In an
explosion, the blast load is applied to structures as an impulsive load of
extremely short duration with very high pressure and heat.
Generally, concrete is known to have a relatively high blast resistancecompared to other construction materials. However, normal strength
concrete structures require higher strength to improve their resistanceagainst impact and blast loads. Therefore, a new material with high-energy717

October 2009, Incheon, Korea

absorption capacity and high resistance to damage is a better material for
blast resistance design. Recently, Ultra High Strength Concrete (UHSC) andReactive Powder Concrete (RPC) have been actively developed tosignificantly improve concrete strength. UHSC and RPC can improve
concrete strength, reduce member size and self-weight, and improve
workability. Commonly, UHSC and RPC produce compressive strength
greater than 150MPa and sometime up to 180~200MPa. High strength
concrete are used to improve earthquake resistance as well as constructionsof high-rises and long span bridges. Also, UHSC and RPC can be
implemented to blast resistance design of infrastructure against terror or
impact (ASCE, 1999; Baker, 1973).
The Korean building code has been modified in year 2009 where any highrises located in the city of Seoul with the height of over 50 above groundfloors or 200m, the terror resistant design has to be incorporated. This code
regulation reflects the keen public interest on blast resistance and protective
design concepts. However, since UHSC or RPC has been recently
developed, their blast resistant capacities have never been studied. In orderto properly and efficiently incorporate UHSC and RPC into protective
design scheme, an in-depth research on blast resistance behavior on UHSC
and RPC is urgently needed at this time (Kim, 2009; Zineddin et al., 2007).
Therefore, in this study, the blast tests are performed to investigate thebehavior of UHSC and RPC slabs subjected to blast load. Blast wave
characteristics including incident and reflected pressures as well as
maximum and residual displacements and strains in steel and concretesurface are measured. Also, blast damages and failure modes were recorded
for each specimen. From these tests, UHSC and RPC are shown toeffectively resist blast explosions compared to normal strength concrete.
Based on these test results, the blast design procedure will be suggested.
2. LITERATURE LEVIEW
2.1

Characteristic of blast load

An explosion is a very fast chemical reaction producing transient airpressure waves called blast waves. For a free-air burst, the blast wave willtravel away from the source as a spherical wave front as shown in Figure1(a). The peak overpressure and the duration of the overpressure vary with
distance from the explosives. The magnitude of these parameters also
depends on the explosive materials from which the explosive compound ismade. Usually the size of the explosive compound is given in terms of a
TNT weight. Explosive behavior depends on a number of factors: ambient
temperature, ambient pressure, explosive composition, explosive material
properties, and the nature of the ignition source type. Additional factors
include type, energy, and duration of the events as well as geometry ofsurroundings (i.e., confined or unconfined). When a condensed highexplosive is initiated, explosion reaction generates several additional
characteristics such as blast wave of very high pressure, fragmentation fromthe explosive case or structural elements, hot gas with a pressure from 100

718

New Technologies for Urban Safety of Mega Cities in Asia

up to 300 kilobar, and a temperature of about 3,000～4,000℃. The main
blast effect is impulsive pressure loading from the blast wave as shown in
Figure 1(b) (Baker, 1973; Mays and Smith, 1995).

Pso

W

Normal distance, RA
Horizontal
distance

Path of shock propagation
normal to surface
Shelter

Positive specific impulse, is

Pressure

Path of shock propagation to point
other than the normal point

Angle of incidence, αPstA

Ambient, Po
Pso–

Negative specific impulse, is
–

tA+to

tA+to+to–

Ground surface

Ps

0
Positive phase
Duration, to–

Negative phase–
Duration, to(a) Spherical free air blast(b) Pressure-time history
Figure 1: Spherical free air blast (TM5-1300, 1990; Kim et al, 2007)
After a short time, the overpressure behind the shock front drops
rapidly and becomes smaller than that of the surrounding atmosphere asshown in Figure 1(b). This pressure domain is known as the negative phase.
The front of the blast wave weakens as it progresses outward and its
velocity drops toward the velocity of sound in the undisturbed atmosphere.
The characteristics of a blast wave resulting from an explosion depend
mainly on the physical properties of the source and the medium throughwhich blast waves propagate. To create reference blast experiments, some
controlled explosions have been conducted under ideal conditions. To relate
other explosions with non-ideal conditions to the reference explosions, blast
scaling laws can be employed. The most widely used approach to blast wave
scaling is that formulated by Hopkinson, which is commonly described as
the cube-root scaling law. The scaled distance, Z, is defined using the
Hopkinson-Cranz's cube root law as (ASCE, 1999):
Z = R / E1/ 3 or Z = R / W 1/ 3

(1)where, Z is scaling distance; R is stand-off distance from the target
structure; E is total explosive thermal amount of energy; W is charge weightof equivalent TNT amount. The scaling distance is used for evaluation of
blast wave characteristics.
2.2

Research trends

Concrete is generally known to have a relatively high blast resistancecapacity compared to other construction materials. However, concrete
structures, which were not designed to have blast protective capacity,require retrofitting during their service life to improve their resistanceagainst blast loads. Retrofitting method of attaching extra structuralmembers or supports to increase the blast resistance is inefficient in theperspective of additional construction cost and eliminating useable space.
Also, since this method does not greatly improve the overall structuralresistance against blast load, a more feasible method of retrofitting to
improve blast resistance would be to use Ultra High Strength Concrete(UHSC) or Reactive Powder Concrete (RPC). UHSC and RPC would also

Experimental Study of Ultra High Strength Concrete and Reactive Powder Concrete Structures under Blast Load 719

October 2009, Incheon, Korea

be very effective in new constructions since they can be used for concretematerials in reinforced concrete members.
In fact, beams and plates constructed using high strength concrete(HSC) showed better impact resistance capacity than ones made using
normal strength concrete (NSC) in past researches. However, due to socialand governmental constraints, this type of comparison study has not been
carried over to blast resistance capacity study, resulting in insufficient
database of HSC’s role as blast resisting material (Kim, 2009).
Recently, several researchers have pursued static and impact capacity
studies on fiber reinforced concrete members under time-dependent loading
conditions. The reference study has shown that the impact and blast loaded
UHSC or RPC study results are non-existing and blast loaded HSC study
results are scarcely existing at best (Habel et al, 2008).
3. BLAST TEST DETAILSIn this paper, the failure behaviors of reinforced UHSC and RPC slabs underblast loading are studied. The tests were performed as 2 step process of
preliminary and main tests at Agency for Defense Development of Korea’s
testing sight. In the preliminary test stage, TNT 35lbs was used as blast loadon control specimens (NSC specimen). After the trial tests, ANFO 35lbs
was selected as the blast explosive charge to be used for the main test stage.
3.1 Blasting test setup
In this study, in order to eliminate the 3-D effect, RC slab specimens
are placed at a same level as ground surface (Razaqpur et al., 2007). A steel
frame is constructed and buried in the ground as shown in Figure 2(a). For
preventing the supporting frame distortion during blast loading, thestiffeners with 250mm spacing are installed on wall surface of supporting
frame. Rubber pads of the same width and length as the steel angle legs
were placed between the angles and test specimen to ensure uniform supportconditions. The explosive used for the test was spherical ANFO, which washeld by wooden horizontal bar. Figure 2(b) shows the test specimen setup
with the 35lbs ANFO (28.7lbs TNT) explosive charge. The 1.5m standoff
from specimens to explosive middle point is consistently maintained.

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New Technologies for Urban Safety of Mega Cities in Asia

(a) Buried supporting frame(b) Explosive charge and specimen
Figure 2: Overview blast setup
3.2 Specimen Manufacturing and Details
For the relative and absolute comparisons between the specimens
casted with UHSC, RCP, and NSC RC slabs with the dimensions of
1,000×1,000×150mm and D10 (71.33mm2) mesh type reinforcements with
82mm spacing are used. The steel ratio of the reinforced NSC and UHSC
specimens is same as the 2 volume % of short steel fibers used in RPC
specimen. The mix proportions for NSC, UHSC, and RPC are tabulated inTable 2, 3, and 4, respectively. The 100×200mm cylindrical specimens areprepared for compressive and tensile strength tests performed at Hyundai
Institute of Construction Technology. The number of specimens tested for
NSC, UHSC, and RPC are 2, 4, and 4 specimens, respectively. The averagecompressive strength of NSC, UHSC, and RPC are 25.6, 202.0, and 203.0
MPa, respectively. The compressive strengths with a deviation over 15% areeliminated from consideration. The tensile strength of RPC is approximately
2.3 times greater (21.4MPa) than NSC (2.2MPa) and UHSC, (9.21MPa),
respectively, due to the addition of 2 vol.% of short steel fibers in RPC.
Table 2: Mix proportion of normal strength concrete (NSC)Max. Size
Targetof Coarse
Slump W/B S/aStrength(mm) (%) (%)
Aggregate
(MPa)
(mm)
25

24

100

49.8 47.7

Binder
(kg)

Water
(kg)
163

FA (kg)Cement Fly-ash S1
294
33
616

S2
264

CA
(kg)

AE
(kg)

957

2.45

Table 3: Mix proportion range of ultra high strength concrete (UHSC)
W/B (%)< 20

S/a (%)< 39.1

Water (kg)
< 140

Binder (kg)< 1300FA (kg)< 450

CA (kg)< 700

AE (%)
1~3

Table 4: Mix proportion range of Reactive Powder Concrete (RPC)
W/B
(%)
< 20

Cement Water Silica Fume
Admixture SteelFA (kg) Filler (2.2~200 ㎛)
(kg)
(kg)
(%)
(%)
Fiber (%)
< 800 > 200
10~30 800~1000
200kg ~
1~3
2

3.3 Measurement outline
The free field incident pressure was measured at 5m from the center of
the test slab specimens where reflected pressure on concrete specimen wasmeasure at the center of the top surface of the specimen and 230mm fromthe center. (e.g., 1/3 point of specimen diagonal length). To measure strain,
6mm strain gauges are attached on reinforcing steel at tensile region and30mm strain gauges are attached on concrete top and bottom surfaces asshown Figure 3. In case of retrofitted specimen, FRP strain gauges areattached instead of concrete strain gauges on bottom surface. Also, LVDTs
on the specimen center are used to measure the maximum and residual
displacements.

Experimental Study of Ultra High Strength Concrete and Reactive Powder Concrete Structures under Blast Load 721

October 2009, Incheon, Korea

1000 mm

230 mm

230 mm 230 mm

230 mm

500 mm<BOTTOM><TOP>

230 mm
D10

LVDT (Behavior displ.)
LVDT (Residual displ.)

30

230 mm

500 mm

500 mm

460 mm

100 mm1000 mm

100 mm

460 mm1000 mm150

Pressure transducer

30

Strain Gauge
Accelerometer(a) Steel strain gauge(b) Gauges on concrete surface
Figure 3: Location of measuring sensor
4. BLAST TEST RESULTSUHSC and RPC RC slabs are blast loaded to analyze their resistance
performance. In the preliminary testing stage, NSC RC slab was tested toestimate the blast cracking behavior and the required explosive charge
weight for the main tests.
4.1 Blasting tests
When ANFO 35lbs was used as the explosive charge, extreme waveof high pressure, temperature, noise, and energy dispersed out radially. The
photos in Figure 4 are ANFO 35lbs detonation photos. Since ANFO
detonation produces debrisless explosion, giving a more of pure pressure
type of explosion loading, ANFO explosive charge is used for the main tests.

Figure 4: Explosive scene by ANFO 35lbs
4.2 Measured blast results
Due to the exploded metal debris of TNT steel container impacting
and damaging the pressure gauge installed in the center–top surface of thespecimen, the compressive blast pressure data was not obtained in the
preliminary stage. The measured free field and reflected pressures of ANFO
35lbs are shown in Figure 5. And the other data are tabulated in Table 6.

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New Technologies for Urban Safety of Mega Cities in Asia

The measured data are inconsistent due to the variations in experimental andenvironmental conditions (i.e., charge shape, charge angle, wind velocity,
humidity, etc.). However, the obtained blast pressure data seem to agree
well with ConWEP data.
30

0.30
Incident pressure_ConWEP

25

Free field Pressure_UHSC2Free field Pressure_ RPC2

0.20

Reflect pressure (MPa)Free field pressure (MPa)

0.25

0.15
0.10
0.05

Pressure_ConWEP

20

Reflect Pressure_UHSC2
Reflect Pressure_ RPC2

15
10
5
0

0.00

-5

-0.05
0

10

20

Time (msec)

30

0.0

40

0.5

1.0

1.5

Time (msec)

2.0

2.5

3.0

(a) Free field pressure(b) Reflect pressure
Figure 5: Measured pressure on specimens (ANFO 35lbs)
The incidental and residual deflections are measured from the blast
test. Both deflection results of maximum and residual measurements aretabulated in Table 6. In the preliminary tests using TNT 35lbs, themaximum measured deflection at the center of the specimen was beyond
25mm measurement capacity of the LVDT. The specimen center deflectiontime histories for NSC-TNT 35lbs, which exceeded LVDT measuring
capacity, and NSC-ANFO 35lbs are shown in Figure 6. As shown in Table 6,
the maximum and residual deflections from ANFO 35lbs for NSC, UHSC,
and RPC are 18.57mm and 5.79mm, 12.83mm and 3..86mm, and 11.91mm
and 4.31mm, respectively. As shown in Table 6, the bottom center concrete
strains were over 16,000με for NSC, UHSC, and RPC specimens. However,when the strain measurements and displacements for NSC, UHSC, and RPC
specimens are compared, RPC data at the specimen center tend to be lessthan those of NSC and UHSC specimens. This result is probably due to theshort steel fiber reinforcing in RPC specimen where the fibers restrained
crack opening by crack bridging and controlling effect.
Table 6: Test results
SPECIMEN
ChargeTemp.
Humid (%)
Center (MPa)
Impulse (MPa-msec)
Reflect
Pressure
230mm (MPa)
Impulse (MPa-msec)
Peak overpressure
Free Field
Pressure
Impulse (MPa-msec)
Max. displacement (mm)Average of max displ.(mm)Residual displacement (mm)Average of residual displ.(mm)Steel up
Steel bottom
StrainConcrete up
Concrete bottom
Environment* NR : Not Record* UHSC : Ultra High Strength Concrete

NSC1_2
NSC2
TNT
ANFO
35lb
35lb
11
5
31
up 51
NR
3079.64
NR
NR
NR
3854.4
NR
473.5
30.06
23.40
49.25
33.3
over 25
18.56518.56512.260
5.790
9.025
16012
5964
15998
28113
NR
11848
16007
NR

UHSC1
UHSC2
ANFO
ANFO
35lb
35lb
8
NR
56
NR
NR
2454.1
NR
561.7
NR2720.7
NR
437.6
36.15
27.63
27.66
33.4
10.517
15.14
12.829
1.860
5.86
3.860
2796
2832
6711
7553.6
4502
12821
NR
NR

RPC1
RPC2
ANFO
ANFO
35lb
35lb
-9
NR
39
NR
NR
3189.9NR409.93280.93205.3294.4
477.75
23.14
27.74
33.25
30.42
10.73
13.09
11.910
3.202
5.41
4.306
11198
24214
NR
4903

* NSC : Normal strength concrete(control specimen)* RPC : Reactive Powder Concrete* - : Non-attached gaugesExperimental Study of Ultra High Strength Concrete and Reactive Powder Concrete Structures under Blast Load 723

October 2009, Incheon, Korea

50Over range

Displacement (mm)

-5

-10

-15

NSC_TNT 35lbs
NSC_ANFO 35lbs

-20

-25

-30
0

50

100

150

200

T ime (msec)

Figure 6: Displacement behavior of concrete specimen (NSC) center point
under blast loading
4.3 Tested Specimen Examination
When the testing is completed and the safety is insured for theinspectors, the surface examination of the specimen was performed. Figure7(a), 7(b), and 7(c) are the schematic drawings of NSC, UHSC, and RPC
slab bottom surface crack distributions after ANFO 35lbs blasting,respectively. The NSC specimens had a well dispersed turtle back typecrack pattern. The crack lines followed the cone prism type of plastic yieldline from the center to the 4 corners, indicating a 2D membrane plastic
failure mode. However, UHSC specimen’s crack pattern showed mostly
macro-cracks concentrated near or on the yield lines. The RPC specimens
showed predominantly one directional, center bisecting type, macro-cracks.
Since RPC specimen is made using cement mortar with short fibers, it
tended to be brittle but the crack bridging effect of short fibers resisted crack
propagation where the macro-cracks form only in the direction perpendicular
to the principle tensile strain direction as shown in Figure 7(c).
NSC2

UHSC1

RPC2

(a) NSC(b) UHSC(c) RPC
Figure 7: The crack pattern of blasted specimens (bottom side)724

New Technologies for Urban Safety of Mega Cities in Asia

Owner Specs & Standards

Building Requirements :Criticality, Occupancy, Layout,
Siting, etc.

Explosion Hazard
Identification

Standard
Practice

Site
Study

New

Existing

Free Field Blast
Parameter

Building Performance
Requirements

Component Loads

Select Materials & Structural
SystemMaterial
Properties

Preliminary Member Sizes

Deformation
LimitsAnalysis Method
HFPB (High Fidelity
Physics Based)

SDOF

MDOF
Structural Analysis
Is
Deformation Limit
Satisfied?

Foundation Design

Yes

No

Ancillary Design

Details & Documentation

Figure 8: Blast design and analysis process
4.4 Blast design and analysis process
Based on the blast tests for NSC, UHSC, and RPC in this study, theblast design and analysis process are suggested. Most improtantly thebuilding and owner requirements are needed for determination of blast
resistance capacity of a targeted structure. To evaluate the building
requirements, the blast loading on each component and resistance capacity
can be derived from test results or research reports. If materials andstructural system are selected, determination of deformation limit using
analysis method such as HFPB (High Fidelity Physics Based) and SDOF,
MDOF, etc. is selected for the blast analysis. The details of design will beaccompanied with satisfaction of the deformation limit based on the analysis
results.
5. CONCLUSION
From this study, Ultra High Strength Concrete (UHSC) and Reactive
Powder Concrete (RPC) RC slabs’ response induced by explosive of blast
wave pressure are evaluated to understand the blast resistance capacity blast
resisting repair materials and retrofitted structure. The reflected blastpressure and impulse values calculated using the ConWEP were in
reasonable agreement with the experimental data. The performancecomparison of UHSC and RPC specimens to NSC control specimens
subjected to blast loads of ANFO 35 lbs has shown the high blast resistancecapacity of about 30.9~35.9% increase with respect to average maximum
displacement. An average of residual displacements was smaller thannormal strength concrete specimen’s residual displacement, even though
there was no consistent trend due to variations in environmental conditions.
Therefore, to evaluate the damage under blast load, failure mode must be
considered. From the test results, the failure patterns of both UHSC and
RPC indicate that they are much more resistant to blast loading and havehigher blast resistance capacity than NSC.

Experimental Study of Ultra High Strength Concrete and Reactive Powder Concrete Structures under Blast Load 725

October 2009, Incheon, Korea

ACKNOWLEDGMENTS
The research was supported the financial support provided Hyundai
Engineering and Construction Co., Ltd and KOGAS from Ministry of Land,
Transport and Maritime Affairs (Design standard of extremely large storagetank and optimum analysis technique).
REFERENCES
ASCE, 1999. Structural Design for Physical Security: State of the Practice
Report. Task Committee on Physical Security, American Society of Civil
Engineers, New York.
Baker, W.E., 1973. Explosions in Air. Wilfred Baker Engineering, San Antonio.
Harbel, K., and Gauvreau, P., 2008. Response of Ultra-High Performance
Fiber Reinforced Concrete (UHPFRC) to Impact and Static Loading. Cement
and Concrete Composites, Vol.30, 938-946.
Kim, H.J., Nam, J.W., Kim, S.B., Kim, J.H.J., and Byun, K.J., 2007.
Analytical Evaluations of the Retrofit Performances of Concrete Wall
Structures Subjected to Blast Load, Journal of the Korea Concrete Institute,Vol.19, No.2, 241-250.
Kim, J.H.J., 2009. Experimental Evaluation for the Blast Resistance Capacityof Concrete Structure using Ultra High Strength Concrete. Report of Hyundai
Institute of Construction Technology.
Mays, G.C., and Smith, P.D., 1995. Blast effect on Buildings: Design of
Buildings to Optimize Resistance to Blast Loading. Thomas Telford.
Razaqpur, A.G., Tolba, A., and Contestabile, E., 2007. Blast Loading
Response of Reinforced Concrete Panels Reinforced with Externally Bonded
GFRP Laminates. Composite Part B : engineering, Vol. 38, 535-546.
TM5-1300/AFR 88-2/NAVFAC P-39, 1990. Structures to Resist the Effects ofAccidental Explosions. Joint Departments of the Army, Air Force and Navy
Washington, DC.
Zineddin, M., and Krauthammer, T., 2007. Dynamic Response and Behavior
of Reinforced Concrete Slabs under Impact Loading. International Journalof Impact Engineering, Vol. 34, 1517-1534.

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New Technologies for Urban Safety of Mega Cities in Asia

OPTICAL SENSOR AND
NEURAL NETWORKS FOR REAL-TIME
MONITORING AND ESTIMATION OF
HAZARDOUS GAS RELEASE RATEWON SO, JAMIN KOO1, DONGIL SHIN2,KYOSHIK PARK3 and EN SUP YOON1
1
School of Chemical & Biological Engineering, Seoul National University,
Seoul 151-744, Korea
2
Dept. of Chemical Engineering, Myoungji University,
Yongin, Gyeonggi-do 449-718, Korea
3
Institute of Gas Safety R&D, Korea Gas Safety Corp.,
Siheung-shi, Gyeonggi-do, Korea
sowon3036@pslab.snu.ac.kr

ABSTRACTIn this research, we propose a new method for estimation of therelease rate using the concentration data obtained from the sensor network.
We used optical sensor of the fence concept that has already been set
surrounding the area where hazardous gas releases can occur. From realtime monitored data, we detected and analyzed releases of hazardous
materials and their concentrations. Based on the results, the release rate isestimated using the neural network. This model consists of 14 input
variables and one output. Case studies with chlorine and ammonia will begiven to illustrate the implementation process. The proposed technique canprovide precise estimates of release rates that can improve the accuracy
and availability of information necessary for the success of the emergency
information delivery system.

1. INTRODUCTION
Economic development and ever-increasing adoption of technology foreveryday life have unavoidably introduced many dangerous facilities inside
and nearby city. Accidental discharges of dangerous gases, either flammableor toxic, more likely to occur during manufacture, storage or transport could
be considered as one of those cases. A feeling of insecurity for residents
living nearby dangerous facilities increased, but response technologies are
not accepted to be adequate [1, 2]. Many studies on real-time monitoring areprogressing. The research of monitoring system based on sensor-network ispractical to be applied in the field. However, existing methods are not easy
to predict the release rate of toxic material using sensor-network. Thus, thisresearch proposes a methodology for estimating release rate of toxic gases.
This paper focuses on releases of material which are highly toxic gases

727

October 2009, Incheon, Korea

produced and used in large quantities around the world. For example,
chlorine, a highly toxic gas that is widely used for water disinfection, is
produced and used in bottles of several dozens of kilograms all over theworld [1].
In this research, we use an optical sensor network that has already been set
up and operational surrounding an area where hazardous gas releases canhappen. From real-time monitored data, we detect and analyze harmful
materials releases and their concentrations. Based on the results, the rate ofrelease is estimated using the neural network. This model consists of 14
input variables (sensor data, material properties, process information andmeteorological conditions) and one output (release rate). Case studies withchlorine and ammonia will be given to illustrate the implementation process.
The proposed technique can provide estimates of release rates that can
improve the accuracy and availability of information key to the success of
emergency information delivery system.
2. BACKGROUND
The availability of various dispersion models, artificial neural networks, andsensory equipments allowed the development of the monitoring techniqueproposed here. Thus, conceptual and practical description of each will begiven throughout the rest of this section.
2.1

Dispersion models

There are three types of dispersion models that vary in complexity andapplication domains: three-dimensional, SLAB, and Gaussian. Threedimensional models solve conservation of mass, momentum and energy
equations and are especially effective in modeling the dispersion of clouds
in complex geometry with obstacles. SLAB models are particularly usefulwith heavy gas dispersion. Gaussian models assume the distribution ofdispersed molecules with standard deviations dependent on the atmosphericconditions and distance from the source [1].
In the context where the proposed technique is to be applied,geometrics of areas of interests may be complex but can be of a wide variety.
Furthermore, hazardous gases whose release the technique attempts tomonitor may be light or heavy. As a result, Gaussian model is selected as
the dispersion model and the commercially available software PHAST is
used in training the neural networks.
2.2

Neural networks

Neural networks are composed of simple elements operating inparallel. These elements are inspired by biological nervous systems. As in
nature, the network function is determined largely by the connections
between elements. One can train a neural network to perform a particularfunction by adjusting the values of the connections (weights) between

728

New Technologies for Urban Safety of Mega Cities in Asiaelements. In general neural networks are adjusted, or trained, so that a
particular input leads to a specific target output. The network is adjusted
based on a comparison of the output and the target iteratively until the
network output matches the target. Typically a large number of input/target
pairs are needed to train a network. Neural networks have been trained toperform complex functions in various fields, including pattern recognition,
identification visions and control systems [9].
2.3

Sensory Equipments

Different types of sensors are now available that can detect andmeasure concentrations of gaseous molecules in the perimeter. Among them,
optical sensors appear attractive for their low cost, applicability and highsensitivity [11]. These sensors use the changes of optical absorption
spectrum in reaction with molecules for detecting the target concentration.
The ones used in the proposed technique rely on 4 submits for measuring
the concentration: light-emitter, optical receiver, spectrum analyzer andconcentration computing machine (fig. 2).

Figure 1: composing parts of the singular sensor network
3. METHODOLOGY
The combination of optical sensor network, back-propagation neuralnetworks and the Gaussian dispersion model can build an effective, realtime monitoring system for storage vessels containing hazardous materials
3.1 Allocation of optical sensors
Optical sensors should be located in the way that the chances
coverable area misses detection/measuring of releases is minimized,

Your Paper Title

729

October 2009, Incheon, Korea

hopefully almost zero. With the optical sensors described in section 2.3, asingle sensor forms a coverable area that extends cylindrically between thesurface of the light emitter and receiver, as denoted by ci. Meanwhile, thestorage vessels containing hazardous materials-target for monitoring-forms
an arbitrary three dimensional region H within which optical sensors
attempt to detect/measure releases. Assuming that optical sensors detect andmeasure releases with a probability of 1 if the released molecules passthrough the coverable area, the optimum allocation of n sensors is possible
with respect to chances of detection/measuring and costs of sensors as in
the following.
(1)

min

where p(x,y,z) is the probability that the released molecules pass the
Cartesian point (x,y,z) within H, is the cost per unit area for not being able
to detect/measure releases, and is the cost for a single optical sensor used.
Clearly, the specific allocation depends on the placement and shapeof storage vessels containing hazardous materials, as well as the costs ofsensors and missed releases. However, it is not easy, in fact cumbersome
and case-specific to identify p(x,y,z) and ; if these are known, then the
problem becomes a mathematical programming for which numerous
solutions are available [12]. In a test experiment, a square H with 4 sensors
placed at 1m above the ground that from a square-like fence around H has
been tested for detection of releases.

Storage vessel

Optical sensor

Area HCoverable area

Figure 2: test experiment with 4 sensors covering a square H

3.2 Training the neural network
With the installation of optical sensors in the manner described in
Section 3.1, the remaining issue is how to train the neural network. Since

730

New Technologies for Urban Safety of Mega Cities in Asia

the proposed technique is designed to estimate the hazardous gas releaserate, this becomes the target output layer in the neural network. The input
layer consists of the selected input data from table 1. Then, the backpropagation algorithm is applied to calculate the weights between the input
layer and the hidden layer of 20 units, and between the hidden layer and theoutput layer, under the MATLAB software package.
Table 1: Parametric sensitivities of input variables
Release rate

Dispersion

Data
Light gas

Heavy gas

Light gas

Heavy gas

Distance from source

0.0000 a

0.0000--Concentration

0.00000.0000--Wind velocity

0.00000.0000649

375

Atmospheric stability

0.00000.0000220

88Temperature

0.00000.000067

21

Relative humidity

0.00000.0000143Storage pressure

0.04440.0623118

46

Storage temperature

0.00240.002913

10Storage quantity

0.0000c

0.0000

3

5

Molecular weight0.04430.0443105

105

Density0.02980.0674

157

251

Boiling point

0.00000.000000Melting point

0.00000.000000Vapor pressure

0.00000.000000a

The respective variable has no influence on the release rate.
The concentration is the output variable in terms of which the dispersion parametricsensitivities have been calculated. Thus the obvious result, unitary sensitivity, has beenrecorded.
c
The exact calculation result was not zero, but a number less than 0.0000 when rounded up.
b

There have been a limited number of release accidents in the past. So,a total of 1600 data generated from PHAST have been used for calculating
the aforementioned parametric sensitivities. This is a size large enough togive R greater than 0.900 when a single kind of hazardous molecule is to bemonitored; the specific value shows slight variance for different types ofhazardous materials (Table 2). When more than one hazardous material ismonitored, R remains acceptable while MSE increases like in Table 2. In
this study, release rates of four different chemicals were estimatedseparately first, and then they were added to see how MSE changes (Fig. 3).
As shown in the graphs, deviations from actual release rates do not increaseYour Paper Title

731

October 2009, Incheon, Korea

substantially when the number of materials does not exceed 4. Indeed, MSE
manages to be less than 0.1, which is still acceptable under the general view
[15].
Table 2: Changes in R and MSE of the trained neural network
1 (Cl2)1 (NH3)

1 (SO2)

R

0.999

0.971

0.981

MSE

0.02250.03160.0399

1

2

3

4

0.941

0.996

0.985

0.992

0.07220.07340.0906

0.0988(C6H6)(a) 1 material(b) 2 materials(c) 3 materials(d) 4 materials

Figure 3: Fitness analysis in the estimation of the release rate
4. CASE STUDY AND DISCUSSION
The proposed technique has been tested by an experiment conducted in aheat treatment factory located in southern East of Incheon City on March,
2008. An optical sensor was installed 100 meters away from the storage
vessel containing ammonia; meteorological conditions were taken from the
Korean Meteorological Administration Office. Ammonia was deliberately
released from the vessel, and its concentrations dispersed at 100m away(where the sensor was installed) were measured throughout 3 weeks. The
measurement data are presented in Fig. 4.

732

New Technologies for Urban Safety of Mega Cities in Asiabpp

Figure 4: Ammonia concentration measured during a test experiment
As one may notice, measured concentrations deviate around 1,000ppb, or 1
ppm while the ERPG1 (Emergency Response Planning Guideline) of
ammonia is 25ppm. In other words, the experiment was unable to validate
the technique in a scale comparable to realistically threatening scenarios;
therefore, a series of virtual scenarios (Table 3) is tested for reviewing thereliability and validity of the proposed technique. Specifically, theestimation of release rates by the proposed technique is compared against
ones generated by commercially available software like TRACE. Phosgeneand nitrogen oxide have also been included in the comparison so as toensure the applicability of the proposed technique with materials other than
the four mentioned in the previous section.
Table 3: Virtual release scenarios
NH3

Cl2

COCl2

NO2

100 m

200 m

40 m

500 m

Concentration

2,500 ppm

1,000 ppm

200 ppm

100 ppm

Wind velocity

3.0m/s

1.5m/s

4.0m/s2.0 m/s

D

F

C

B

Temperature

7℃

20℃

30℃

10℃

Relative humidity

0.7

0.5

0.3

0.8

Storage pressure

1.0 bar14.7 bar

2.0 bar

2.0 bar

Storage temperature

-20℃

25℃

20℃

10℃

Storage quantity

1,000 kg

2000 kg

100 kg

500 kgDistancefromsourceAtmosphericstability

Each scenario has been modeled with input variables of different
magnitudes so that their collective range covers most of the accidents
reported in Korea [14]. While the proposed technique directly estimates theYour Paper Title

733

October 2009, Incheon, Korea

release rate with the given input variables, it takes a trial and error approachfor the commercially available software. The results are presented in Table
4.
Table 4: Comparison of release rates against by PHAST & TRACE
NH3

Cl2

COCl2

NO2

Proposed Method

0.5727 kg/s

0.4849 kg/s

0.0764 kg/s

21.8927 kg/s

PHAST

0.6124 kg/s

0.4538 kg/s

0.1011 kg/s

21.9242 kg/s

TRACE

1.3015 kg/s

0.5887 kg/s

0.0416 kg/s

20.5200 kg/s

As illustrated in table 4, the proposed technique estimates the release rate
within acceptable differences except for ammonia. The proposed techniqueestimates a value within 10% from that by PHAST, but the difference ismore than 50% when compare to the result by TRACE. This is mainly due
to the fact that the proposed technique is based on the Gaussian dispersion
model like PHAST while TRACE is based on the slab model which isappropriate for heavy gases [1]; however, ammonia is a typical light gas.
This tendency can be observed even when the target material is not a light
gas like chlorine. The proposed technique gives values closer to that of
PHAST for sharing the same dispersion model.
5. CONCLUSION
An efficient, real-time monitoring technique is proposed that can estimate
the hazardous gas release rate by using optical sensor and neural networks.
The comparison against widely used commercial software like TRACE and
PHAST illustrate that the proposed technique can estimate release rates
within acceptable differences; the proposed technique does so with a far lessnumber of input variables in a shorter period of time-within seconds.
Consequently, it offers advantages against the traditional monitoring
systems in which release rates are, in the first places, assumed rather thanestimated. The accurate, spontaneous measurement of release rates is crucial
for taking immediate responses in the outbreak of release accidents. The
proposed technique can be used to estimate this value, thereby contributing
to the building of a more effective information delivery system. Additional
validation of the technique with more materials will ensure its applicability
in broader situations.

Nomenclature
C100\

concentration (ppm) of dispersed molecules at 100 m away fromthe source
ci area that extends cylindrically between the surface of the light emitter andreceiver734

New Technologies for Urban Safety of Mega Cities in Asia

di input data of type iH

arbitrary three dimensional region within which optical sensors

detect/measure releasep(x,y,z) probability that the released molecules pass the Cartesian point (x,y,z)
within H
release rate in kg/s
s1

parametric sensitivity of an input variable with respect to release rates2

parametric sensitivity of an input variable with respect to dispersed

concentration
cost for a single optical sensor used
cost per unit area for not being able to detect/measure releases

REFERENCES[1] A. Dandrieux, J. P. Dimbour, G. Dusserre, 2006, Are dispersion models
suitable for simulating small gaseous chlorine releases, J. Loss Prevention
19, 683-689.
[2] M. Abbaspour, N. Mansouri, 2005, City hazardous gas monitoring
network, J. Loss Prevention 18, 481-487.
[3] R. K. Chohan, 1989, Safety and fault detection in process control
systems and sensors, Fire Safety J. 14, 167-177.
[4] R. W. Lee, J. J. Kulesz, 2008, A risk-based sensor placement
methodology, J. Hazard. Mater. 158, 417-429.
[5] S. Guo, R. Yang, H. Zhang, W. Weng, W. Fan, 2009, Source
identification for unsteady atmospheric dispersion of hazardous materials
using Markov Chain Monte Carlo method, Int. J. Heat and Mass Transf. 52,
3955-3962.
[6] S. T. Chung, K. I. Kim, 2009, Case studies of chemical incidents andemergency information service in Korea, J. Loss Prevention 22, 361-366.
[7] S. Alhajraf, L. Al-Awadhi, S. Al-Fadala, A. Al-Khubaizi, A. R. Khan,
S. Baby, 2005, Real-time response system for the prediction of theatmospheric transport of hazardous materials, J. Loss Prevention 18, 520525.
[8] H. Havens, M. E. Luther, S. D. Meyers, 2009, A coastal prediction
system as an event response tool: Particle tracking simulation of ananhydrous ammonia spill in Tampa Bay, Mar. Pollut. Bull. 12[9] A. T. C. Goh, 1995, Back-propagation neural networks for modelingcomplex systems, Artificial Intelligence in Engineering 9, 143-151.
[10] A. Arranz, S. Bordel, S. Villaverde, J. M. Zamarreno, B. Guieysse, R.
Munoz, 2008, Modeling photosynthetically oxygenated biodegradation
processes using artificial neural networks, J. Hazard. Mater. 155, 51-57.
[11] C. Massie, G. Stewart, G. McGregor, J. R. Gilchrist, 2006, Design of a
portable optical sensor for methane gas detection, Sens. Actuators, B 113 ,
830-836.

Your Paper Title

735

October 2009, Incheon, Korea[12] A. D. Belegundu, T. R. Chandrupatla, 1999, Optimization concepts andapplications in engineering, Prentice-Hall, New Jersey[13] D. A. Crowl, J. F. Louvar, 2002, Chemical Process Safety
Fundamentals with Applications, Prentice Hall, New Jersey[14] J. Koo, S. Kim, H. Kim, E. S. Yoon, 2009, A systematic approach
towards accident analysis and prevention, Korean J. Chem. Eng. 26, 262269.
[15] B. Pradhan, S. Lee, 2007, Utilization of optical remote sensing data
and GIS tools for regional landslide hazard analysis using an artificial
neural network model, Earth Sci. Frontiers 14, 143–152.

736

New Technologies for Urban Safety of Mega Cities in AsiaEARLY EMERGENCY SYSTEMSBASED ON 3DGIS FORDISASTER PREVENTION SAFETY-CITY
YOUNG-JIN PARKNational Institute for Disaster Prevention,
National Emergency Management Agency, Korea
yjpark@nema.go.kr

ABSTRACTThe rapid development of the information technology has passed overthe implementation of the virtual reality. Virtual Reality has been applied tomany fields: military, design, manufactory, information management,
business, construction, disaster management, etc.. It is realizing information
services that are form of the globalization, based on the Internet. In addition,
the effort to apply IT to public administration for public services has beenmade. The remarkable development of computer hardware has overcome thelimit of the information distribution and emerged for practical use invarious fields such as public institution, underground facilities management,
tourism industry development etc.
Geographic information system data and products have become apowerful resource, which is being utilized at all levels within our society.
However, the practical use of Virtual Reality with Three-Dimensional GIS
on disaster management by Korea National Emergency Management
Agency is very much low.
This studies focus on how to use 3-Dimensional GIS for the purpose offire disaster prevention. This paper presents an integrated Early Response
Emergency System that uses 3D-GIS as the model source, CAD as the model
generating tools, ArcGIS as analysis platform tools. This paper also
discussed, through understanding of the limitations of 2-Dimensional GIS,
the establishment of basis for fire prevention technology development andits utilization among those ubiquitous city paradigms, which have become
so much issues these days.

1. INTRODUCTION
The most representative instances of the services are environmental
geographic information system of the Ministry of Environment, aerial
photography information system of National Institute of Science, satellite
image search system of the Ministry of Land, Transport and Maritime

737

October 2009, Incheon, Korea

Affairs, geographic information system of Nuclear emergency management
geographic information system, national park interview service, the service
system of touring the national parks, etc.
As an Internet powerful country, we have 12.2 Fiber/LAN Internet service
subscribers per 100 people as of the end of June, 2008, the first 1 place inranking among the OECD 30 member countries, Japan, the second placewith 10.2, Sweden, the third place with 6.0. However, comparing with theInternet subscription and access, its development seems to be restricted dueto the limited kinds of contents and the higher dependency of software.
Investment must be presciently made to develop the software of our own
engine with dynamic ideas and more various kinds of contents through thecooperation between the private, Government, and academic sector.
Outside of the country, the United States, United Kingdom, Japan etc. havealready built the 3 dimensional spatial information systems, and speedilylead an information age by providing the users with real sense of spatial
information via web-base Internet. The diversified spatial information items
are also freely applied to the spatial information industry field creatively.
As for the overseas countries, a private sector has firstly developed theterrain spatial information, which spreads to the open space on line fromthe restricted off-line place. In terms of the proposals and publicity activities
to the national institution and the government and public offices, they aremaking a global standard in an industry information field both by ensuring a
distribution network and creating benefits through the network linked byand between the private, Government, and academic sector.
This study, reviews will be made on the application importance and planabout the emergency management field, using GIS, especiallycomplementing its business and analytical function which have not been
embodied in the two-dimensional GIS, and an introduction will be madeabout the application instance of 3 dimensional GIS to copy with the social
demand and expectation for multidimensional spatial information.
Especially, a research will be made on the application plan of 3 dimensional
GIS, both by making a foundation for the technical development ofemergency management information to embody the u-Safety City in linewith this research and through an illustrative review over its application plan.
Emergency management system can be briefly defined as the application of
the GIS in the parts of the National land, City emergency management, etc.
This means the application state or system, where the previous disaster
information is processed in a database based on the GIS, and the GIS isusefully made use of both in a emergency management plan and daily worksof management.

738

New Technologies for Urban Safety of Mega Cities in Asia

2 ROLES AND FUNCITON TO UPGRADE NATIONAL DISASTER
MANAGEMENT
It is necessary to approach the disasters more from software side in order toprepare a scientific and systematic disaster plan, respond swiftly to the disasters,
effectively rehabilitate the disasters. In this connection, we need to make areasonable means to forecast the risk, extent, and size of the damage, not tomention the hardware emergency management policy like the installation ofexisting emergency management facilities. In order to achieve this, thefollowing role and function are necessary in connection with the u-Safe Korea,
which is being planned by the National Emergency Management Agency.
An integrated emergency management information DB is necessary to build
in order to manage the national disasters. In order to build a country strong
against disasters as well as to minimize at least the damages from the disasters,
it is necessary to more actively carry out the project to build spatial
information data related to disasters for each field according to the 6th generalplanning of emergency management. It is also necessary to build a databaseof spatial information for each type of disaster as per the place where it
happens. Moreover, It is necessary to build a practical DB both throughsystematic data classification and checking the applicability on the basis ofresearch result of terrain, geological features, soil, ground and floodgate.
An integrated disaster management system needs to be built with theprecondition of liaison between related authorities and business alliancesystem. The e-government project, which was sought by the old Ministry ofGovernment Affairs and Home Affairs, is clearly stated as building ageneral service of national security management based on the e-government
road-map thirty one(31) tasks. To seek this, liaison and cooperation isdefinitely required by and between the related authorities.

Figure 1: Disaster fighting & Decision-making support system situation
propagation system of a local autonomous entity

Early Emergency Systems Based on 3DGIS for Disaster Prevention Safety-City739

October 2009, Incheon, Korea

It is necessary to solve the problems of technical disaster management
which fights the variety of disasters and enhance the capability to confront
the disasters through active use and application of high technology inemergency management field by upgrading the disaster fighting function
and role, which have introduced GIS new technology.
2.1 Task for the application of multidimensional information
Emergency support navigator development for special purpose
vehicles is proposed that a emergency management information navigatorbe developed for the exclusive use by special purpose vehicles, for which
both of the spatial information where the information either of the facility inthe disaster place, or of the place subject to disaster, or the danger
facilities(city gas, drainage, hydrant, etc.) in the surrounding area are
specified in detail, and of the detailed theme mapping is provided, where thedetailed floor plan, spatial bird's-eye view, evacuation route, expectedmovement line, etc. are specified for the building of a certain facility which
is highly subject to disasters.

Figure 2: Development figurative of Navigatorfor special purpose vehicle
The joint application system of the national disaster management now
being built and updated by the National Emergency Management Agency
can be called a disaster situation manifestation system, which statisticallymanifests the real time disaster information collected from the nationwide
disaster management system installed in Seoul and 16 cities and provinces
all over the country. In order to perform this task, a test bed area wasselected where it is easy both to collect the data for three dimensionalmodeling like numerical value mapping, aerial photos, fire protection data
information, etc. and to design and build a prototype for the target area.

740

New Technologies for Urban Safety of Mega Cities in Asia

2.2 Regional range and prototype of testbed
The test-bed was implemented New City of Dongtan in Hwaseongcity known as a sample of u-City was considered as second test bed area.
However, the whole area of Bansong-dong in New City of Dongtan was
selected as a target area of prototype designing, considering the difficulties
with information safety in providing the data like aerial image photos andsatellite photos, which are necessary in building a prototype. The test bed
will be built in the whole area of Bansong-dong 17 in the city of Hwaseong,and the multiplex facility of Shinyoung Plaza building with 9 floors was
selected as target building.
In this research, a prototype was built in connection with the prototype
system demonstratively developed for the situation control, the research
result of the “Standard Model Development of u-safe City” which had beensought by the National Emergency Management Agency in the year of 2007.
The implementation of the testbed monitors the condition of counterfire facilities and structures and provides the person in charge with 24
hour/365 day real-time remote monitoring. If problems arise, alarm is
automatically issued via 3D Web GIS based mobile systems so that the
problem can be taken care of anywhere, anytime.
Especially, a prototype was built for the on-the-spot situation action toincrease the adequacy of the application of fire monitoring service done in
the previous research, on-the-spot action, and perception capability ofdisaster situation. Besides this, a domain was built for the fires happening inconnection with human disaster, and "Disaster Situation Monitoring
Service" was built for the purpose of on-the-spot action and handling thepost-disaster problems.

Figure 3: Situation monitoring service scenario assumption

Early Emergency Systems Based on 3DGIS for Disaster Prevention Safety-City

741

October 2009, Incheon, Korea

3 ESTABLISHMENT OF PROTOTYPE STABLISHMENT OF SCENARIOFOR ON- THE-SPOT ACTION
This prototype scenario covers the on-the-spot situation management anddisaster action for the "Disaster Situation Monitoring Prototype" out of thesafety management services for the facilities subject to disaster and calamity(Standard Model Development of u-safe City, National Emergency
Management Agency, 2007), the basic services of u-safe City.
The disaster control center of local autonomous entity or the control centerof the fire fighting jurisdiction authorities is assumed as an integrated
control center of the system, with a decision making support system which
exchanges the information, in dualistic way, with a vehicle for moving to
the disaster place (fire engine, emergency vehicle, special purpose vehicle,etc.).
The prototype in this research was designed so that a navigation can be used
for a special purpose vehicle (fire engine, emergency vehicle, special
vehicle, etc.) moving to a disaster place immediately after receiving such anorder, assuming the disaster control center of local autonomous entity or thecontrol center of the fire fighting jurisdiction authorities as the integrated
control center of the system. In addition to this, the scenario was preparedwith a purpose to build an unidirectional disaster fighting monitoring system,
which is grafted on to the real time action against the disaster place bymaking use of the intelligent type CCTV, which is receiving an attention
recently for the purpose of information safety, crime prevention and security
1) Arrangement function of emergency fighting vehicle

Figure 4 : Arrangement function of emergency fighting vehicle

742

New Technologies for Urban Safety of Mega Cities in Asia

○ Center:- Constant support for emergency task of the group responsible foron-the-spot action- Arrangement of fire fighting vehicles & Entry simulation to
extinguish fire
○ Vehicle:- Before moving·While moving(Possible to simultaneously control with the Control Center)- Proper arrangement of emergency vehicles & Entry route simulation- Recognize overall emergency action by projecting the spatial floor
plan of the entire building- Discuss on fire extinguishing & disaster fighting while the group in
charge are moving to the place2) Location of hydrant inside Building

Figure 5: Location of hydrant inside Building○ Center:- Constant control of the flat surface inside the building in 3 dimensions- Check the location and usability of Fire Extinguisher inside thebuilding○ Vehicle:- Before moving·While moving(Possible to simultaneously control with the Control Center)- Check fire ignition point & available fire fighting equipments on thelinked floor- Discuss on fire extinguishing & disaster fighting while the group in
charge are moving to the place

Early Emergency Systems Based on 3DGIS for Disaster Prevention Safety-City743

October 2009, Incheon, Korea

4 CONCLUSIONSThis prototype system was built for the test bed, and a 3 dimensional
database was also built with the 3 dimensional transformation tool bymaking use of the existing 2 dimensional data. For the testbed, a prototype
was built by making use of a [Monitoring system of emergency area
situation action system]. For each situation by a scenario built, an
explanation for each system and a detailed description for application plan
were made. Especially, the system was test-run for the fire-fighting public
servants now attending the University of Seoul to look into the application
possibility and problems of this prototype system, obtaining an application
plan of the research result and its improvement plan.
The improvement plan and application result of the developed prototype
system are arranged as follows.
- The system can be jointly used by the situation control center and thearea office unilaterally or bilaterally.
- The upgraded situation control system can be more actively used.
- It is expected that the system will be more widely used considering
its on-the-spot action capability and detailed information.
It is the important point for the future system application both to increase
the on- the-spot action capability by making use of the intelligent type
CCTV and to develop the contents which provide the area situation
realistically (considering the fact that the disaster situation system presently
being used in each government ministry was upgraded, and both of thedigital and real picture camera are actively used to take a picture of adisaster area situation). The system will provide the information whichenables the users to expand the width of decision making.
As the present monitoring system has a variety of problems both technicallyand financially, like the enormousness of size, high cost, restricted provisionof information, etc., it is important to provide each user with the information
by adjusting its quantity by differently adjusting the equipment size and its
application as per the location and time in consideration of the situation
control center, emergency vehicle, on-the-spot action, etc.
For the recent skyscrapers, complex buildings, etc., fire prevention plan has
been prepared to a certain degree. However, as for the old facilities etc.,
they are easily subject to disasters because of their building floor plan etc.
It is necessary to preferentially develop a system for the places which areeasily subject to disasters, including the area between a city and farm village,
general small-scale fire fighting targets, hot old housing district, etc.

744

New Technologies for Urban Safety of Mega Cities in AsiaACKNOWLEDGMENTS
The authors would like to acknowledge Dr Sung Ho, Kim from the
University of Seoul, and Technical Manager of Sung Heon, Jung from EGIS
CO., LTD for their valuable contributions to this work.

REFERENCES
Kim, Sang Bong., Cho, Woo Jin, A Study on the Development and Application of
3Dimensional Spatial Information of Virtual City Using Digital Photogrammetry,
Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography, 2007.
Park, Inhye., Jun, Chulmin., Lee, Jiyeong, Geographic Information System
Association of Korea, GIS-based Fire Evacuation Simulation using CA Model,
2008.7
Korea Institute of Construction & Transportation Technology Evaluation and
Planning, Construction of the 3D Virtual Land Information and Development of its
Application, 2006.8.19
Seoul Development Institute, A Study on development of Seoul Virtual City using
3D GIS, 2006
Jeremy Morley, 2003, MasterMap in Academia-Experiences at UCL(University
College London)
P. Frederiksen. J, Grum. L.T, Joergensen, STRATEGIES FOR UPDATING A
NATIONAL 3D TOPOGRAPHIC DATABASE AND RELATED GEOINFORMATION,
National Survey and CadastreJ
Masahiko Murata, 3D-GIS Application for Urban Planning based on 3D City
Model, ESRI International User Conference 2004

Early Emergency Systems Based on 3DGIS for Disaster Prevention Safety-City

745

IMPACT RESISTANCE OF REINFORCED
CONCRETE WALL OF BREAKWATERCAISSON1

TAKU. MATSUBAYASHI, M. IWANAMI and 2HIROSHI YOKOTA
1Port and Airport Research Institute, Japan,(matsubayashi, iwanami)@pari.go.jp
2
Hokkaido University, Japan, yokota@eng.hokudai.ac.jp

ABSTRACTThis paper describes experimental investigations on mechanicalbehavior of reinforced concrete (RC) walls under repeated impact loads,
which are often observed in concrete caissons for breakwaters. In theexperiment, mechanical behavior of one-way RC slabs under repeatedimpact loads was examined by conducting falling-weight impact loading
tests. In the tests, two kinds of repeated impact loads were applied: repeatedimpact loads of which velocities were increased gradually from 1.0m/s to
6.0m/s, and repeated impact loads with constant velocity of 3.0m/s. The
reinforcement ratio was changed to investigate the influence on the impact
behavior of the slabs. As the results, it was found that the failure mode of all
the test slabs was punching shear failure after yield of tensile reinforcement.
Also, it was made clear that the number of repetition of impact loading until
the ultimate failure was increased and that the maximum deflection of theslab was decreased, in case of RC slabs with higher reinforcement ratio. It
was because increase in reinforcement ratio caused improved flexural
rigidity and punching shear capacity. Accordingly, it was concluded that
impact resistance of one-way RC slabs could be improved by increasing
reinforcement ratio, showing the possibility of concrete caissons with higher
resistance against impulsive wave forces or impact forces due to collision of
concrete blocks.

1. INTRODUCTION
Figure 1 shows the typical structure of caisson-type breakwater in Japan.
Filling materials such as sand are filled inside the reinforced concrete
caisson to get sufficient weight. Moreover, there are concrete blocks in frontof the caisson to reduce the wave forces. It is reported that huge impulsive
wave forces or impact forces due to settlement of concrete blocks are acting

747

October 2009, Incheon, Korea

Caissonabout 15m
Sand

RC Wall(thickness: about 40cm)
Concrete Blocks(weight: about 50t)

Figure 1: Typical structure of caisson-type breakwater

Photograph 1: The hole of the caisson-wall
repeatedly on such concrete structures, resulting in ultimate failure ofconcrete members (Hirayama, et al., 2005). Photograph 1 shows the hole ofthe caisson-wall which occurred by the impulsive wave forces. When thewall gets a hole, the sand inside the caisson is flown out, reducing theweight of caisson. It is serious because the stability of the caisson decreases.
In the present design of such concrete structures (Port and Harbor
Association of Japan, 2007), impulsive wave forces, that have large
variations with regard to time and space, are converted to equivalent
distributed static loads in order to compare with the load carrying capacityof the structures in static conditions. Therefore, it is one of the problems thatscatters of impulsive wave forces and dynamic behavior of concrete
structures are not taken into account. A lot of studies on reinforced concrete(RC) members subjected to impact loading have been carried out (Kishi, etal., 2002, Chen, et al., 2009, Saatci, et al., 2009). However, the impact
resistant design method considering such phenomena appropriately has notbeen completed.
In addition, it is necessary to examine countermeasures to improvestructural performance of concrete members against repeated impact loads,
which is applicable to breakwater caissons. However, there are few studies
dealing with mechanical behavior of RC members subjected to repeatedimpact loading. In static conditions, the load carrying capacity of RC
structures is improved by increasing reinforcement ratio. Similarly, it isexpected that impact resistance of concrete members may be improved by748

New Technologies for Urban Safety of Mega Cities in Asia

increasing reinforcement ratio. Therefore, in this study, to investigate theinfluence of reinforcement ratio on impact resistance of caisson-typebreakwaters, mechanical behavior of one-way RC slabs with different
reinforcement ratios under repeated impact loads was examined byconducting falling-weight impact loading tests.

2. EXPERIMENTAL OUTLINE
2.1 Test slab
Two kinds of RC slabs were prepared: normal RC slabs (A-series) andRC slabs with higher reinforcement ratio (B-series). The reinforcement ratioof A-series is designed to be almost the same as the wall of concrete
caissons. The tensile reinforcement ratio of B-series is about twice as muchas that of A-series. The sizes of both series of slab are 1500mm in width,
160mm in thickness, and 2300mm in length, as shown in Figure 2. The
slabs were tested under simply supported conditions with a shear span of
1000mm, leaving a 150mm overhang at each end. The thickness and span of
the slabs are about 2/5 of the typical prototype of the wall of concrete
caissons for breakwaters.
2.2 Material properties and calculated mechanical capacity of RC slab
Concrete and reinforcement used in the slabs have been widely
applied in Japan. Table 1 lists concrete properties obtained fromcompressive tests on cylinders at the time of impact loading tests. Table 2
lists the yield stress of reinforcement from tensile tests. Table 3 presents
static capacities of RC slabs which are calculated according to “Standard
Specifications for Concrete Structures,” published by Japan Society of Civil
Engineers (2007).
Upper side
reinforcement
D10
D10

150

150×11=1650
Compressive
reinforcement
D10(SD345)

2000
2300

A-series

130 90Tensilereinforcement
D10(SD345)

150

70
Anchorplate(t=6mm)160
30 100 30

90 130Anchor transverse
plate reinforcement(t=6mm)D6(SD345)
160
30 100 30

Ｃ
Ｌ

Lower side
reinforcement
D13
D13

1500
100×14=1400

D10

1500
125×11=1375

D6

100×21=2100

70

transverse
Compressive
Tensilereinforcement
reinforcement reinforcement
D10(SD345):upper
D10(SD345)
D13(SD345):lower D10(SD345)

150

2000
2300

B-series

150（unit：mm）

Figure 2: Shape and dimensions of test slab

Impact Resistance of Reinforced Concrete Wall of Breakwater Caisson749

October 2009, Incheon, Korea

SlabseriesA
B

Table 1: Concrete properties
Compressive
Designation
strength(N/mm2)
A-1
40.8
A-2
44.3
B-1
40.8
B-2
44.3

Young’smodulus(kN/mm2)
30.2
30.4
30.2
30.4

Table 2: Yield stress of reinforcement
Yield stress
Steel bar
(N/mm2)
D6
365
D10
384
D13
380

Slab
seriesA
B

Table 3: Calculated static capacities of RC slabs
FlexuralPunching shear
Designation
capacity
capacity
(kN)
(kN)
A-1
95.1
175.2
A-2
96.5
175.2
B-1
182.7
253.6
B-2
184.6
253.6

2.3 Impact loading test
Table 4 summarises the test cases. In the tests, two kinds of repeatedimpact loads were applied: repeated impact loads of which velocities wereincreased gradually from 1.0m/s to 6.0m/s (Loading Method I), and repeatedimpact loads with constant velocity of 3.0m/s (Loading Method II). These
impact velocities were determined in consideration of velocities of
impulsive wave forces measured in actual breakwaters (Arikawa, et al.,2005). For the repeated impact loading tests, an impact loading testingmachine was used, as shown in Photograph 2. A steel weight is lifted to thepredetermined height by a small crane, and the weight free-falls by releasinga hook. The weight is dropped onto the center of the top surface of the slab.
The mass of the weight is 400kg, and the impact face of the weight has aspherical shape with a diameter of 565mm. Figure 3 shows the shape of thesteel weight. To prevent the slab from bouncing out, the slab is held withsteel beams at the two supporting points. To reduce scatters of impact
response, caused by local damage of the top surface of the slab, a rubber
sheet of 10mm in thickness is placed at the impact position of the slab.

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New Technologies for Urban Safety of Mega Cities in Asia

Table 4: Test cases
SlabseriesA
B

Designation

Loading
method

A-1
A-2
B-1
B-2

I
II
I
II

Impactvelocity V(m/s)
1,2,3,4,5,6
3
1,2,3,4,5,6
3

Photograph 2: Impact loading testing machine

Load Cell［unit: mm］

Figure 3: Shape of steel weight
The ultimate state of the slab was defined as clear formation ofpunching shear cracks in the slab. The impact loads were applied repeatedly
until the ultimate state.
The impact force developed between the weight and the slab wasmeasured using a load cell mounted to the weight. The reaction forces at
supporting points were measured using load cells set at the supporting
devices. The midspan displacement of the slab was measured using a lasertype displacement sensor. Also, cracks of the slab were observed
periodically during the tests.

Impact Resistance of Reinforced Concrete Wall of Breakwater Caisson751

October 2009, Incheon, Korea

3. EXPERIMENTAL RESULTS
3.1 Results of impact test by Loading Method I
All the test slabs showed the punching shear failure after yield of
tensile reinforcement. Figure 4 shows the relationships between impact
velocity and displacement of the slab measured at the center of the bottom
surface. The maximum displacement of A-1 increased from 1.5mm to63.1mm when the impact velocity increased from 1.0m/s to 6.0m/s.
Similarly, the maximum displacement of B-1 increased from 0.3mm to44.0mm. It was found that the maximum displacement and residual
displacement of B-1 became smaller than those of A-1. Therefore, thedeflection of RC slabs subjected to repeated impact loading can be mitigatedby increasing reinforcement ratio.

Displacement (mm)Both A-1 and B-1 reached the ultimate state when the impact velocity
was 5.0m/s. Photograph 3 shows the damage state of the bottom surface ofthe slabs. Punching shear failure of RC slabs occurred regardless of thedeflection state when the impact velocity was relatively large.
0
10
20
30
40
50
60
70

A-1（Maximum）
A-1（Residual）
B-1（Maximum）
B-1（Residual）
0

1

2
3
4
5
Impact velocity （m/s）

6

7

Figure 4: Impact velocity vs displacement of the slabs

V = 6.0m/s

V = 1.0m/s(a) A-1

V = 1.0m/s

V = 6.0m/s(b) B-1
Photograph 3: Appearance of bottom surface of the slabs

752

New Technologies for Urban Safety of Mega Cities in Asia

3.2 Results of impact test by Loading Method II
All the test slabs showed the punching shear failure after yield of
tensile reinforcement. Figure 5 shows the relationships between number ofrepetition of impact loading and displacement of the slab measured at thecenter of the bottom surface. The displacement of slabs increased
remarkably at the stage of smaller numbers of repetition. Then after a slow
progress, the displacement again increased acceleratedly with approaching
the ultimate state. The whole tendency of the relationship drew an S-shaped
curve. Figure 6 shows the crack patterns of the bottom surface of slabs fortypical numbers of repetition. According to the observation of crack patternsof A-2, flexural cracks and radial cracks occurred at the bottom surface ofthe slab after the first impact loading and the amount of these cracks
increased until about the 10th impact loading. Afterwards, these cracks did
not increase so much until about the 25th impact loading. After about the

20
40
60
Maximum
Residual800

Displacement（mm）

Displacement（mm）

0

100

20
40
60
Maximum
Residual

80
100

0

10
20
30
Number of repetition

40

0

50
100
Number of repetition

150(a) A-2(b) B-2
Figure 5: Number of repetition vs displacement of the slabs

[1]

[25]
(a) A-2

[35]

[1]

[100]
(b) B-2[150][ ]; Number of repetition

Figure 6: Crack pattern of test slabs subjected to repeated impact loads

Impact Resistance of Reinforced Concrete Wall of Breakwater Caisson753

October 2009, Incheon, Korea

25th impact loading, punching shear cracks occurred. As shown in Figure 5(a), the tendency of displacement progress was changed when the numbersof repetition were 10 and 25. Therefore, the tendency of displacement
progress relates to the damage state of slab. It is supposed that the cause of
rapid progress of the displacement until 10th impact loading was decrease inflexural rigidity of the slab due to increase in number and width of cracks.
The cause of further progress of the displacement after 25th impact loading
is considered that the punching shear capacity of the slab was declined by
the occurrence of punching shear cracks.
In case of B-2, the whole tendency was similar to A-2 (S-shape
curve). However, the amount of cracks of B-2 was much more than that of
A-2. The number of repetition of B-2 until the ultimate state was about fivetimes of A-2, and the displacement of B-2 until the ultimate state was about
1/3 of A-2. It was because that increase in reinforcement ratio caused
improved flexural rigidity and punching shear capacity. Therefore, it is
supposed that the number of repetition of impact loading until RC slabs
reach punching shear failure can be increased by increasing reinforcement
ratio when the impact velocity is relatively low, showing the possibility of
improving the performance of port concrete structures against impulsive
wave forces or impact forces due to collision of concrete blocks.
Figures 7 and 8 show the relationships between number of repetitionof impact loading and maximum impact forces and maximum reaction
forces measured by load cells mounted to the falling weight and supporting
500
Impact force（kN）

Impact force（kN）

500
400
300
200
100

400
300
200
100
0

0
0

10
20
30
Number of repetition

0

40

50
100
Number of repetition

150(a) A-2(b) B-2
Figure 7: Number of repetition vs maximum impact force
500
Reaction force（kN）

Reaction force（kN）

500
400
300
200
100
0

400
300
200
100
0

0

10
20
30
Number of repetition

40

0

50
100
Number of repetition

150(a) A-2(b) B-2
Figure 8: Number of repetition vs maximum reaction force

754

New Technologies for Urban Safety of Mega Cities in Asia

Reaction forces（kN）

500
1st peak

400

1st
5th
25th

2nd peak

300
200
100
0
-100
0

5

10
15
Times（ms）

20

25

Figure 9: Time history of reaction forces (A-2)

Displacement（mm）

0
5
10

1st
5th
25th

15
20
0

5

10
15
Times（ms）

20

25

Figure 10: Time history of displacement (A-2)
devices. As for the maximum impact forces, the tendency of measured data
was consistent with the tendency of displacement (S-shape curve), as shownin Figure 5. It is supposed that the decrease in flexural rigidity anddeclination of punching shear capacity of the slab influenced the impact
force.
As for the maximum reaction forces, the tendency of measured data
was not consistent with the tendency of displacement. Figure 9 shows timehistory response of reaction force in case of A-2 for typical numbers ofrepetition. There are two kinds of peak in the waveform (first peak: ● ,second peak:▲ ). In case of the first impact loading, the first peak of reaction
force was larger than the second one. In cases of the 5th and 25th impact
loadings, the first peak was smaller than the second one. This phenomenon
suggests that the factor to produce the maximum reaction force is different.
Figure 10 shows time-history response of displacement of the slab measured
at the center of the bottom surface in case of A-2. The first peak does not
relate to the time when the displacement reached the maximum. The firstpeak decreases as the number of repetitions of the impact loading increases.
Therefore, it is supposed that the reaction force at the first peak relates to the
local damage of the slab at the impact point. The waveform including thesecond peak is roughly corresponding to the flexural deformation of the slab.
Therefore, it is supposed that the second peak relates to the flexure of slab.

Impact Resistance of Reinforced Concrete Wall of Breakwater Caisson755

October 2009, Incheon, Korea

4. CONCLUSIONS
Based on the experimental results of repeated impact loading tests on oneway RC slabs, the following conclusions can be drawn:- The deflection of RC slabs can be mitigated by increasing reinforcement
ratio.
- Punching shear failure of RC slabs occurred regardless of the deflection
state when the impact velocity is large.
- The number of repetition of impact loading until punching shear failure
can be increased with increase in reinforcement ratio when the impact
velocity is low.
- Increase in reinforcement ratio has the possibility of improving thestructural performance of caisson-type breakwaters against impulsive
wave forces or impact forces due to collision of concrete blocks.

REFERENCES
Arikawa, T., Ikebe, M., Osaki, N., Kuroda, T., Orita, T. and Shimosako, K.,
2005. Study on punching shear failures of caisson wall caused by theimpulsive force of dissipating blocks, Report of the Port and Airport
Research Institute, V.44, No.1, 43-83. (in Japanese)
Chen Y. and May, I. M., 2009. Reinforced concrete members under dropweight impacts, Structures and Buildings, V.162, Issue SBI, 45-56.
Hirayama, K., Minami, Y., Okuno, M., Minemura, K., Kawai, H., Hiraishi,T., 2005. Case study on wave disaster due to typhoons in 2004, Technical
Note of the Port and Airport Research Institute, No.1101. (in Japanese)
Kishi, N., Mikami, H., Matsuoka, K.G. and Ando, T., 2002. Impact
behavior of shear-failure-type RC beams without shear rebar, International
Journal of Impact Engineering, V.27, 955-968.
Saatci, S. and Vecchio, F.J., 2009. Effects of Shear Mechanisms on Impact
Behavior of Reinforced Concrete Beams, ACI Structural Journal, V.106,
No.1, January-February, 78-86.
Standard Specifications for Concrete Structures-2007, Design, Japan
Society of Civil Engineers, 2007. (in Japanese)
Technical Standards and Commentaries for Port and Harbour Facilities inJapan, Port and Harbor Association of Japan, 2007. (in Japanese)756

New Technologies for Urban Safety of Mega Cities in Asia

A BASIC STUDY ON DEVELOPMENT
OF NEW TRAINING SYSTEM
FOR BUILDING DAMAGE ASSESSMENT
1

MAKOTO FUJIU, 1MIHO OHARA and 2KIMIRO MEGURO
1
Interfaculty Initiative in Information Studies,
The University of Tokyo, Japan
2
ICUS, Institute of Industrial Science, The University of Tokyo, Japan(fujiu, ohara, meguro)@iis.u-tokyo.ac.jp

ABSTRACT
Building damage assessment is necessary for governments to issue theVictim Certificates for residents who suffered housing damages. The
process of assessment needs accuracy, quickness, objectivity and fairness
because the results of assessment are used as criteria for providing public
monetary supports for rebuilding their livelihood. In Japan, several big
earthquakes are expected to occur in the near future. A lot of structural
damages due to these earthquakes will cause enormous needs for building
damage assessment. However, current number of human recourses who aretrained with the procedure of building damage assessment is not enough. It
is necessary to increase the number of investigators before a next event
occurs. Moreover, recent experiences of assessment after past disasters
pointed out several problems of the current system. Usually, investigators
are consisted of non-experts of structural engineering such as general
officials in local government, who were trained with the assessment
procedure in a very short time after the disaster. Insufficient training led tothe unequal personal skill of judgment and finally caused many
misjudgments of housing damage. In order to achieve quick, accurate,
objective and fair assessment, effective training system for building up
qualified investigators who are familiar with the standard procedure before
disasters is essential.
In this research, new training system for building damage assessment
using virtual reality technology was proposed. First, problems of pastbuilding damage assessment were analyzed and applicability of newtechnologies including virtual reality for achieving ideal training system
was discussed. Then, prototype images of new training system using virtual
reality technology were developed based on the data of totally damaged
houses due to the 2007 Niigata Chuetsu-oki earthquake in Japan.

1. INTRODUCTION
In Japan, several big earthquakes are expected to occur in the near future. A
lot of structural damages due to these earthquakes will cause enormous
needs for building damage assessment. Building damage assessment is757

October 2009, Inchon, Korea

necessary for governments to issue the Victim Certificates for residents who
suffered housing damages. However, current number of human recourses
who are trained with the procedure of building damage assessment is notenough. It is necessary to increase the number of inspectors before a next
event occurs. The guidelines of general procedure for inspecting building
damage and evaluating loss due to disasters were published by the Cabinet
Office in 1968, 2001 and 2009. However, in past disasters, various problemsof building damage assessment have been pointed out such as inspection
accuracy, inspection quickness and lack of human recourses with sufficient
skill of assessment.
In this research, new training system for simulating building damage
assessment using virtual reality was proposed and prototype system wasdeveloped. Recently, several researches using virtual reality have been donein the field of disaster prevention, such as simulators for experiencing
disaster (Doi, 2000) and fire drills (Masumura, 2001) etc. Virtual reality isdefined as moving freely in the space using computer display, head mountdisplay (HMD), screen, web site and so on. Virtual reality technology has
high possibility for drastically enhancing people’s response capacity todisasters.

2. PROBLEMS OF PAST BUILDING DAMAGE ASSESSMENTS
There are 3 inspection stages in building damage assessment such as“Primary Inspection”, “Secondary Inspection” and “Issue of the Victim
Certificates”. Through these stages, damage levels of buildings are decided
by visual inspection. The primary inspection evaluates the damages
appeared on the exterior of a building. The secondary one evaluates not only
the exterior damage but also the interior damage. The purpose of thesecondary inspection is to provide the second opinion for the evaluation
when the owner or resident of a damaged house does not accept the result of
the primary one. Therefore, the primary inspection is carried out for all thedamaged buildings, while the secondary inspection is usually carried out by
request. Finally, Victim certificates for residents are issued from the local
governments.
In past disasters, building damage assessments were carried out inJapan. However, various problems have been pointed out for the pastbuilding damage assessments. We reviewed literatures regarding past
several building damage assessments such as Shigekawa (2005) andclassified reported problems as shown in table 1. As a result, enormous
problems in each inspection stage were obtained. The process of assessment
needs accuracy, quickness, objectivity and fairness because the results of theassessments are used as criteria for providing public monetary supports forrebuilding their livelihood.

758

New Technologies for Urban Safety of Mega Cities in Asia

Table1: Problems of building damage assessment after past earthquakes
Flow of Inspection
Ⅰ-Criteria

2004 Niigata Chuetsu Earthquake①Criteria②Summon ofInspection

Ⅱ-Training of
Inspector③Training④Organize
Ⅲ-Screening⑤Screening⑥Primary
Inspection

Ⅳ-Inspection⑦Secondary
Inspection⑧VictimCertificate

2007 Niigata Chuetsu-oki Earthquake

There is no standard to carry out the building damage assessment. Neither examination
methods nor the inspection methods are clearly provided. Only guidelines were issued by
the Cabinet Office.
(Shigekawa,2005)
Insufficient number of assistant staff
Difficulty in assemble of inspectors(Shigekawa,2005)(Tanaka,2008)
Because method of assessment is different in each local government, training isdifficult.
(Horie,2004)
Difficulty in gathering enough number of Inspectors and keeping inspection quality(Shigekawa,2005)
Limit in on-site inspection for lack of inspectors
Difference between structural engineer's
Inspector's knowledge was insufficient.
(Shigekawa,2005) aspect and the Cabinet Office guideline
Problem concerning inspection accuracy(Tanaka,2008)(Shigekawa,2005) Problem concerning inspection accuracy(Tanaka,2008)
Difficulty in responding to residents who Difficulty in predicting number of(Tanaka,2008)
have dissatisfaction in inspection results
application(Tanaka,2008)(Shigekawa,2005) Needs for assistant staff's
The efficiency of work was low, because the issue of enormous certificates was thefirst time for local governments.
(Yoshitomi,2005)

3. PROPOSAL OF NEW TRAINING SYSTEM FOR BUILDINDDAMAGE ASSESSMENT
Based on the problems of past building damage assessments, we proposedsolutions for improving each inspection stage using new technologies asshown in Table 2. In order to carry out ideal building damage assessment,
all the stages in table 1 should be improved. Among all, this paper
especially focused on the “II. Training of Inspector” stage.
In table 1, we proposed two types of training method. The first one is“a seminar for simulating assessment procedure on virtual reality space
using head mount displays (HMDs)”. Trainees experience building damage
assessment of damaged houses using HMDs. On the simulator, damaged
house are reproduced in the virtual reality space. Because a HMD isprecious and the number of HMDs is limited, trainees are necessary togather in the hall for using it. The second one is “Web based training”. In“Web based training”, we propose “training using web based simulation”
and “training using web based simulation on virtual reality”. There are a lotof advantages in web based simulation. For example, trainees can train at
free time, a lot of people can participate in training at the same time, and it
is easy to manage their results and abilities.
Figure 1 shows the concept of “training system using web based
simulation training on virtual reality”. Trainees access the Learning
Management System (LMS) at free time for studying. Results and abilitiesof trainees are recorded in human resource database by the LMS. The
manager can give inspection licenses according to their abilities in
preparation for large-scale disasters. When a disaster occurs and building

A Basic Study on Development of New Training System for Building Damage Assessment759

October 2009, Inchon, Korea

damage inspectors are needed, the managers can organize assessment teams
using human resource database and dispatch them to the damaged area.
Table 2: Proposal of solutions using new technologies
Inspection Flow
Ⅰ‐Criteria

New Technologies
・Decision of new inspection standard
・Restructuring of new assessment procedure

Seminar・Simulation training on virtual reality space using Head Mount
Display

Web basedtraining

・Web based simulation training
・Web based simulation training on virtual reality

Ⅱ-Training of
inspector

Ⅲ‐Screening

Ⅳ‐Inspection

・Prior screening of severely damaged area by result of aerial survey
・Prior screening of severely damaged area using satellite photographs
・Automatic inspection by image data processing of photographs of damagedbuildings
・Remote inspection by forwarding damage photographs to specialists
・Automatic inspection using portable inspection devices
・Cut down of inspection procedures by using damage information by aerial survey
・Management of damage assessment data based on GIS mapping

Access and Learning
Virtual Reality Simulation

LicenseManagement and record of results
and ability

Learning Management System(LMS)

Trainee or Non-Experts

SummonEarthquake

Database

Organizing Assessment Team andDispatch to Damaged Area

Human Resource Management Using LMS

Figure 1: Concept of web based training system for building damage
assessment

760

New Technologies for Urban Safety of Mega Cities in Asia

4. DEVELOPMENT OF PROTOTYPE TRAINING SYSTEM FOR
BUILDIND DAMAGE ASSESSMENT
Here, prototype system of “training using web based simulation on virtual
reality” was developed. As a part of the system, 3D houses were reproducedin the virtual reality space based on the data of totally damaged houses due
to 2007 Niigata Chuetsu-oki earthquake such as external photographs, theindoor photographs and floor plans. Figure 2 shows a floor plan of the firstand second floor of a modeled house.
Figures 3 and 4 show the prototype images of simulating building
damage assessment of a model house. It is simulation of the primary
inspection. Total damage level of a house is decided based on damagelevels of three factors: externals, inclination and building element (roof,
exterior wall and foundation). This system provides “walk throughfunction”, and a trainee can move freely around a 3D house and inspect its
damage in the virtual reality space on the website. A trainee can understanddirection of his/her eye line in the right “View Direction Window” when
they walk around a house. A trainee can answer the damage level of eachbuilding element by a quiz form and confirm their scores by “Your Record”
window. In addition, when a trainee answers a question, they can get somehints. Their answers, scores and quickness of the building damage
assessment are recorded by the LMS. The results of the study will be fed
back to trainees.

Damaged House by the Earthquake

3D modeling

3D Modeled House

Bath and W.C.
Kitchen

Living room

Living room

Porch

Floor Plan of First Floor

Storage

Floor Plan of Second Floor

Figure 2: Overview of a 3D modeled house

A Basic Study on Development of New Training System for Building Damage Assessment761

October 2009, Inchon, Korea

Your Record

Inspection of Elements (Primary Inspection)
3D View Window

Question: 6 / 10
Correct answer: 2 / 10
Error answer: 4 / 10
Roof
View Direction Window
Exterior Wall
N
W

E
S

Foundation

View Direction

Move View

Q5. Inspection of exterior wall. （Primary Inspection）

Hint!

Please select the level of the damage of exterior wall.
North

East
Answer

South

West

Damage Level

Loss level

Ⅰ

10％

Ⅱ

25％

Ⅲ

50％

Ⅳ

75％

Ⅴ

100％

When the crack is caused,the exterior wall is inspected“damage”.

Next Question

Figure 3: Prototype image of the proposed training system

762

New Technologies for Urban Safety of Mega Cities in Asia

Inspection of Elements (Primary Inspection)

Training Information

3D View Window

Question: 8 / 10
Correct answer: 4 / 10
Error answer: 4 / 10

Roof

View Direction Window

Exterior Wall

N

Foundation

W

E
S

Move View

Q8. Inspection of the roof. （Primary Inspection）

View Direction

Hint!

Please select the level of the damage of the roof.
North

East
Answer

South

West

Damage Level

Loss level

Ⅰ

10％

Ⅱ

25％

Ⅲ

50％

Ⅳ

75％

Ⅴ

100％

Pay attention to the damaged
area of the roof.

Next Question

Figure 4: Prototype image of the training system (after 45 degree rotation)

5. CONCLUSIONSIn Japan, several big earthquakes are expected to occur in the near future. It
is necessary to increase the number of building damage inspectors before anext event occurs. In this research, new training system for building damage
assessment using virtual reality technology was proposed. First, problems of
past building damage assessments were analyzed and applicability of newtechnologies including virtual reality for achieving ideal training system wasdiscussed. Among these problems, this paper focused on the stage of“Training of inspector” and proposed new training system for building
damage assessment using web based simulation on virtual reality.
The prototype images of simulating building damage assessment ofmodel houses were developed based on the data of totally damaged houses
due to 2007 Niigata Chuetsu-oki earthquake. 3D houses were reproduced in
the virtual reality space and trainees can experience procedures of building
assessment by walking around a model house. So far, developed system is
prototype one with several model houses. In the future, we plan to improve
the functions of the system and examine its effectiveness throughexperiments to several trainees.

A Basic Study on Development of New Training System for Building Damage Assessment763

October 2009, Inchon, Korea

6. REFERENCE
Doi, Satoru., Watanabe, S., Honma, M., Yoshino, S., and Oki, A., 2000.
Development of VR Simulator for Fire of Underground Markets : Part1 :Outline of the Simulator and Simulation of Smoke Diffusion, Summaries oftechnical papers of Annual Meeting Architectural Institute of Japan, pp.395396
Masumura, A., Tanaka, T., Ohnishi, N., 2001, Extinguisher simulator with
VR, Proceedings of the Society Conference of IEICE, pp.265
Shigekawa, K., Tanaka, S., Horie, K., Hayashi, H., 2005, Some Regulational
Issues on Building Damage Assessment –A Case Study of Niigata-ken
Chuetsu Earthquake- , Journal of social Safety Science No.7, pp.133-140
Horie, K., Shigekawa, K., Maki, N., Tanaka, S., Hayashi, H., 2005,
Application of Damage Assessment Training (DATS) to Ojiya City following
2004 Niigata-ken Chuetsu Earthquake –Through a Disaster Response
Support Activity for Issuing Victim Certificate- , Journal of social Safety
Science No.7, pp.123-132
Yoshitomi, N., Hayashi, H., Urakawa, G., Shigekawa, K., Tanaka, S., Horie,K., Matsuoka, K., 2005, The Development of a Damage Certificate Issuing
Support System –A new disaster response database schema created for the
Niigata Chuetsu Earthquake- , Journal of social Safety Science No.7,
pp.141-150
Tanaka, S., 2008, A Study on the Building Damage Assessment Processes
for the 2007 Niigata Chuetsu Oki Earthquake Disaster : Kashiwazaki Case
Study , Proceedings of social Safety Science No.22, pp.35-38

764

New Technologies for Urban Safety of Mega Cities in Asia

PARALLEL SESSION 12

ANNUAL ENVIRONMENTAL CHANGESIN RUSSIA ANALYZED BY
REMOTE SENSING DATAHARUO SAWADA and YOSHITO SAWADA
International Center for Urban Safety Engineering
Institute of Industrial Science, University of Tokyo, Japan{sawada, yoshitos}@iis.u-tokyo.ac.jp

ABSTRACT
Russia has about 800 million ha of forest land and not a few
simulation studies show that the global environment change might affectthem. However, there is not enough information which covers the wholearea of vegetated area with the same accuracy. Satellite remote sensing ofcoarse resolution is considered effective to monitor large forest area
because of their frequent observation capabilities. Phenological changes of
ecosystem are greatly related to the changes of natural environment, suchas water, temperature, soil and solar radiation. Growth condition ofvegetation and soundness of ecosystem can be evaluated, if the seasonalchanges of the photosynthesis are continuously monitored. Based on theseideas, we studied to get historical information about seasonal changes ofSiberian forest by using remote sensing data.
After the LMF-KF processing to NOAA Pathfinder data for 20 years(1981-2001), we could get "clear" (cloud-free and noise-free) images with10 days interval for both NDVI and LST (land surface temperature). The
combination of NDVI (LMF-NDVI) and LST (LMF-LST) shows many
possibilities to monitor environmental conditions in vegetated area. For
example, the warm index is useful for zoning the eco-region in global scale
and the freezing index has close relations with the distribution map of
permafrost. The onset and offset day of vegetation growth of each pixel werealso defined and the trends of both days for 20 years were obtained. The
accumulation value of the NDVI between onset and offset, named NOOS
index has high relation with a forest distribution map. The combination of
LMF-NDVI and LMF-LST shows clear idea of the growing season andannual changes are also identified by various indices. The difference of
maximum LMF-NDVI among 1981 to 2001 showed degraded vegetatedareas.
The LMF-KL processing could successfully create noise free images
of NDVI and LST with 10 days interval for 20 years from the NOAA
Pathfinder data. The combination of NDVI and LST showed a unique andeffective methodology for studying forest conditions in this region.

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1. INTRODUCTION
Russia has about 800 million ha of forest land and not a few simulation
studies show that the global environment change might affect them.
However, there is not enough ground information which covers the wholearea of vegetated area with the same accuracy. Therefore, satellite remotesensing with coarse resolution is considered effective to monitor large forest
area because of their frequent observation capabilities.
Phenological changes of ecosystem are greatly related to the changes ofnatural environment, such as water, temperature, soil and solar radiation.
Growth condition of vegetation and soundness of ecosystem can beevaluated, if the seasonal changes of the photosynthesis are continuously
monitored. Based on these ideas, we studied to get historical information
about seasonal changes of Siberian forest by using remote sensing
technology.
Many researches utilize frequent observation satellite such as
NOAA/AVHRR and SPOT/Vegetation for global environment study(Ricotta et al., 1999). In such researches, the "10-day composite images",which are created by choosing the best data in 10 days for each pixel, areoften used to monitor seasonal changes of terrain conditions. The monthly
composite data are not appropriate for monitoring phenological aspects
because most of the seasonal changes of vegetation occur within a few
weeks (Viovy et al., 1992). However, the influences of cloud, haze andsystem noises still remain in the 10-day composite data and that makedifficult to monitor phenology with 10 days interval.
NOAA satellite has a long history of their observation of the Earth and there
are data sets of 20 years of the globe. However, only the NDVI data areused and land surface temperature (LST) data were seldom processed,
although temperature is well known as one of the most importantenvironmental factors.
There are two difficulties for using these data in a long-term analysis. One isthe differences of the radiometric characteristics of sensors on different
NOAA satellites. The other difficulty is the algorithm to minimize both theatmospheric and systematic noises in NOAA data to observe the groundcondition.

2. PROCESSSING METHODOLOGIES
Authors developed the processing method named LMF (Local Maximum
and Fitting) and LMF-KF (Local Maximum and Kalman Fitting), whichmodels the seasonal changes by time series satellite data for monitoring
vegetation conditions.

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New Technologies for Urban Safety of Mega Cities in Asia

2.1 LMF Processing
It is assumed that the seasonal change for each pixel is modeled by
the sum of cyclic functions. It is also considered that model parameters are
determined by the 10 day composite satellite data. Subsequently, thetechnique was developed to produce a new noise-free image using themodels derived for each pixel with time-series data. We call this processing"the LMF model processing". The LMF model processing is composed ofthree steps as follows:
1) Revision of data by setting the adjacent maximum value;
2) Fitting with the time series model by a combination of cyclic
functions;3) Automatic decision to determine the optimum combination of thecyclic functions.
d't = Min[Max(dt −w+1 , dt −w+2 ,L, dt ), Max(dt , dt +1 ,L, dt +w−1 )](1)where dt is the observed variable at the time t, w is the window sizeand d't is the modified variable at time t.
N⎧⎛ 2πkl t ⎞⎛ 2πkl t ⎞⎫ft = c0 + c1t + ∑ ⎨c2l sin⎜
⎟ + c2l +1 cos⎜⎟⎬M⎝⎠
⎝ M ⎠⎭
l =1 ⎩(2)

where ci is a coefficient, t is time (the interval unit), N is the pairnumber of the cyclic function, M is the data number in a period (in case of
NOAA 10 day composite products: M = 36), and kl is the periodicity of eachcyclic function in a period (in case of M = 36 , kl = 1, 2, 3, 4, 6 and 12,
meaning one year, a half year, 4 months, 3 months, 2 months and 1 month
periods, respectively).
AIC = D{log(2πσ ) + 1} + 2( j + 1)

(3)
where D is the number of data, j is a number of functions used and σ
is the standard deviation of the residual.
2.2 LM-KF ModelIn the LMF model processing, it is assumed that the seasonal changes
can be expressed by a combination of linear and trigonometric functions likeEq. 2. Nishiyama (1991) reported that the discrete time variant NMR(Nuclear Magnetic Resonance) spectrum can be estimated when thefrequency components of a signal are known. We applied his algorithm to
the LMF model processing. When considering the set of coefficients {c0,c1,...,c2N+1} of Eq. 2 as the state vector of a state space model, their values
can be estimated (state estimation) with a Kalman filter. The new
methodology, LMF-KF model, was built in order to identify not only
seasonal changes but also year-by-year fluctuations by considering the timedependency of each coefficient, although each coefficient of Eq. 2 is not afunction of time (Sawada et al. 2005).
N⎧⎛ 2πk t ⎞⎛ 2πk t ⎞⎫(2')
f = c (t) + ∑⎨c (t) ⋅ sin⎜ l ⎟ + c (t ) ⋅ cos⎜ l ⎟⎬
t

0

l =1

⎩

2l

⎝ M ⎠

2l +1

⎝ M ⎠⎭

Annual Environmental Changes in Russia Analyzed by Remote Sensing Data

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October 2009, Incheon, Korea

3. SATELLITE DATA PROCESSING
3.1 Result of LMF-KF Processing
The NOAA Pathfinder data from 1981 to 2001 were processed. On
the NDVI data, the large fluctuations originated from noises have been
removed by either method of LMF and LMF-KF. The LMF-KF model
processing reveals the annual changes. As the LST data, we introduced theChannel 4 data of NOAA-AVHRR. The result of the LMF-KF model waswell correspond to the meteorological data derived from AMeDAS in Japan.
3.2 Various Informative Data
After the LMF-KF processing to NOAA Pathfinder data for 20 years(1981-2001), we could get "clear" (cloud-free and noise-free) images with10 days interval for both NDVI and LST. Because both the NDVI and LST
are obtained from the LMF-KF processing, there are many possibilities tomonitor environmental conditions in vegetated area.
The LST data is useful for understanding environmental condition of
the terrain. One of the examples, is the warm index (the summation oftemperature when it is higher than 5 degree C), which is considered usefulfor zoning the eco-region. LST makes us possible to monitor the conditionof the annual changes of warm index in Russia, because the groundtemperature is related to LST although ground coverage affects its value.
Table 1: Various indices derived from NDVI, LST and their combinations
Index

Meaning

NMXV, NMXD

Maximum NDVI, the day

NMNV,NMND

Minimum NDVI, the day

TMXV,TMXD

Maximum LST, the day

TMNV,TMND

Minimum LST, the day

T5S, T5D

Warm index, duration: LST > 5 C deg.

T00S, T00D

Freezing index, days: LST < 0 C deg.

NST5

ΣNDVI : LST >5 C dg.

MNV1

Minimum NDVI : LST>1C deg.

MXV1

Maximum NDVI: LST>1C deg.

NOND

Onset day : MNV1 to MAV1

NOFD

Offset day: MAV1 to MNV1

NOOD

Duration of growing season

NOOSΣNDVI during the NOOD

The LMF-KF processed images brought us the possibilities todevelop further indices by the combination of NDVI and LST (Table 1),768

New Technologies for Urban Safety of Mega Cities in Asia

which could be useful for monitoring various phenological conditions ofvegetated area.

4. ANALYSIS AND RESULTS
We, at first, checked the reliability of the LMF-KF processing methodology
by the simulation data and found that it revealed the surface condition byminimizing the affects of clouds and system noises. After this evaluation,
the 3-color composite images using NDVI and LST were created by our
methodology. These color composite images of every 10 days (Fig.1) for 20
years (more than 720 scenes in total) show very clearly the global dynamics
of surface conditions of Siberian forest.

Figure 1: An example of the color composite image of NDVI and LST

4.1 NDVI and Thermal Data
The images of various indices, such as shown in Table 1, werecreated. The maximum NDVI of each year, for example, is considered as agood indicator for annual changes of vegetation condition as each NDVI
shows the seasonal condition of vegetation coverage. The trend of annual
maximum LST for 20 years is considered the average temperature changesof the surface, which must be related to the effect of global environmental
and changes of ground coverage.
The onset day and offset day of vegetation growth of each pixel
were defined from the maximum and minimum NDVI when the LST has
greater than 1 degree C. The accumulation value of the NDVI between onset
and offset is the NOOS index (Table 1). The NOOS has the highest relation
with the forest distribution map which was reported by the International
Institute for Applied Systems Analysis (IIASA). It seemed that the NOOS
could be used as a good indicator for forest area.

Annual Environmental Changes in Russia Analyzed by Remote Sensing Data769

October 2009, Incheon, Korea

We created the Freezing Index image of each year by using the LST
data. The Mean Accumulated Freezing Index over 20 years (Fig.2) was
compared to the permafrost extent map which had been created by IIASA.
There were similar pattern and satellite information might have advantage
over the map at its annual monitoring capability.

Figure 2: Mean Accumulated Freezing Index

4.2 Seasonal Changes
The seasonal changes are well observed on the NDVI and LST
individually. However, the combination of NDVI and LST shows muchclear idea of the growing season and the trend of vegetation condition ofeach pixel. We think that the LST greater than 5 degree C or 1 degree C is
the growing season and the accumulation of the NDVI during the period isrelated to the vegetation growth, which means the CO2 uptake.
4.3 Annual Changes
The annual changes are also observed through the various indicespresented on the Table 1 as well as the Freezing Index. Fig. 3 is one of such
examples and it shows the difference of maximum NDVI between 1982 and2000. The dark area indicates the degraded area. The changes are very much
related to fire occurrence map in Far East. This fact means that the fire andforest logging are very much correlated each other in this region.

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New Technologies for Urban Safety of Mega Cities in Asia

Figure 3: Forest changes between 1982 and 2000. The difference of the
maximum NDVI of each pixel in both years is calculated. Dark are showshigh degradation.

5. DISCUSSION
The LMF-KL processing could successfully create cloud and noise free
images of NDVI and LST with 10 days interval for 20 years from the
NOAA Pathfinder data. The combination of NDVI and LST is a unique andeffective methodology for studying forest conditions in this region. These
data can be used for further studies on carbon fixation, such as NPP
estimation in this region.

ACKNOWLEDGMENTS
This report is a result of the Study on Estimation of Carbon Storage andFixation in the Boreal Forest funded by the Global Environment Research
Fund of Ministry of the Environment, Japan.
REFERENCES
Nishiyama, K., 1991. A method of Estimating Time-Varying Spectrum
which includes Only Components with Known Frequencies. IEICE
Transactions,Vol. J74-A, 916-918.8.
Ricotta, C., Avena, G. and De Palma, A. 1999. Mapping and monitoring net
primary productivity with AVHRR NDVI time-series: statistical

Annual Environmental Changes in Russia Analyzed by Remote Sensing Data771

October 2009, Incheon, Korea

equivalence of cumulative vegetation indices, ISPRS Journal of
Photogrammetric Engineering and Remote Sensing, 54:325-331.
Sawada, Y., Mitsuzuka, No., Sawada, H. 2005. Development of a timeseries model filter for high revisit satellite data. Proc. the Second Int.
VEGETATION User Conference, pp.83-89
Viovy, N., Arino, O. and Belward, A. S. 1992. The Best Index Slope
Extraction (BISE): A method for reducing noise in NDVI time-series. I. J.
Remote Sens. 13:1585-1590

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New Technologies for Urban Safety of Mega Cities in Asia

EFFECT OF CROWN PROPERTIES OF
CHAMAECYPARIS OBTUSA TREEIN JAPAN FOR DEM CREATIONTAKAHIRO ENDO
ICUS, Institute of Industrial Science, The University of Tokyo, Japantendo@iis.u-tokyo.ac.jp
HARUO SAWADA
ICUS, Institute of Industrial Science, The University of Tokyo, Japan
sawada@iis.u-tokyo.ac.jp

ABSTRACTA numerical simulation of airborne LiDAR (Light Detection andRanging) measurement was conducted to clarify relationship between pulse
density and tree crown properties from viewpoint of creation of Digital
Elevation Model (DEM). The simulation was run in 3D Computer Graphics(3DCG) using a simulated tree which created full polygons using ray
tracing technique. Initial parameters in the simulation were species, age ofstand (size) and pulse density. Chamaecyparis obtusa, which is one ofdominant spices of conifers in Japan, was selected. Tree ages were 25, 35,
45 and 60 years old. Pulse density was 1, 2, 4 and 8 points per square
meters. As the result of analysis of relationship between pulse density andDEM creation, blank pixels which have no points on the ground decreased
in proportion to pulse density. However, blank pixels remained around mainstem of tree in spite of using high pulse density. Moreover, blank pixels
existed around main stem in all cases with different ages. Configuration of
structure of stems and branches around main stem was so complex thatlaser beam could not pass through a tree crown. This study concludes thathigh pulse density is needed for DEM creation, but space around main stem
certainly become blank. It is important to use high pulse density for forest
observation by LiDAR in order to create high accurate DEM.

1. INTRODUCTION
Recently in Japan, elevation has been measured increasingly by airborne
LiDAR, because LiDAR measurement is becoming low cost and produces
accurate spatial elevation maps directly with high efficiency in comparison
to ground survey (Hirata, 2004). Then, DEM generated from LiDAR data iswidely used for multiple purposes. However, still there is considerable
difficulty in producing DEM in thickly forested area. Some researchers andsurvey companies pointed out the difficulty of creation of DEM under trees(Endo, 2009). For example, one case was to create DEM easily and the773October 2009, Incheon, Korea

other case was difficult, when DEM was generated from LiDAR Data. This
reason has not been made clear from viewpoint of quality yet. Because, we
can not figure out true geographical position of a target laser beam hit. That
is to say, there is unknown behavior between crown properties and laser
pulse. Hence, a simulation system is needed to comprehend relationshipbetween pulse density and crown properties. The objective of this study
from viewpoint of DEM creation was to investigate relationship between
pulse density and crown properties such as configuration of foliage, stems
and branches using a numerical simulation system.

2. MATERIALS AND SIMULATION CONDITION
2.1

Test tree

A Chamaecyparis obtusa was simulated by a tree growth model(natFX) in the 3DCD software. The tree is one of dominants spices in Japanand is distributed almost throughout Japan. About 12％ Japanese forest area
is covered by this tree (Forestry Agency). To investigate effect of crownproperties such as size and branches, 25, 35, 45 and 60 years old tree werecreated. Figure 1 shows a simulated polygon of Chamaecyparis obtusa
which is 60 years old.
2.2

Pulse density, emitting direction and diameter of foot print

Presently, 4 pulses per square meters is used in commercial operations.
Pulse density will become 8 pulses per square meters in near future. Then, 1,
2, 4 and 8 pulses per square meters were used in the simulation toinvestigate an effect of pulse density by representing presently available
data to the data available in near future. Emitting direction of Laser beam
was vertical as in practical measurements. Also diameter of foot print was
0.2m to simulate practical measurement from 1000ｍ height and 0.2 mrad.
2.3

Points cloud simulation

Points cloud was simulated using a ray tracing method using tree
polygon data in the 3DCG. A geographical positions of origin of ray tracing
specific pulse density was created on a plane which was created on a upper
polygon of tree. Points cloud was a geographical position where a ray
intersected with the tree polygon. Figure 2 stands for the simulated points
cloud generated from a tree polygon of 60 years old and 8 pulses per square
meters.
2.4

DEM creation

DEM was created by a simple rasterization method with 1 meter mesh.
Value of a specific mesh was number of points on the ground in the mesh.
When no point existed in the mesh, value was 0. This case assumed that774

New Technologies for Urban Safety of Mega Cities in Asia

DEM was not able to be created. Figure 3 stands for a result of DEM
creation.

(a)(b)
Figure 1: The simulated polygon of Chamaecyparis obtusa of 60 years old.
(a) is perspective view and (b) is vertical view.

Effect of Crown Properties of Chamaecyparis Obtusa Tree in Japan for DEM Creation775

October 2009, Incheon, Korea

Figure 2: The simulated points cloud of 60 years old by 8 pulse per square
meter density. Black colored circle are points cloud on a tree polygon.
Black colored dot are points cloud on the ground.

Figure 3: Potential of DEM creation. Black colored circle are points cloudon the ground. Gray colored circle are number of points cloud in the mesh.
Black colored solid line is an edge of tree crown.

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New Technologies for Urban Safety of Mega Cities in Asia

3. RESULTS AND DISCUSSION
3.1

Relationship between pulse density and DEM creation

Figure 4 shows relationship between ratio of creation of DEM andpulse density. Ratio of creation of DEM in any year old was increasing in
proportion to pulse density. The relationship between the ratio and pulse
density was a logarithmic function. The result indicates the ratio has upper
limitation value.
3.2

Relationship between DEM and crown properties

To investigate the reason for the logarithmic function, number ofpoints cloud on the ground within a circle with specific radius was analyzed.
Radius in the analysis was from 1.0 to 5.0 meters at the interval of 0.5
meters. Figure 5 is relationship between number of points cloud on the
ground.
Number of points cloud on the ground increased out of 2m range ofradius. At the less than 1.5 m range, there was no point on the ground in any
pulse densities. The reason was an effect of configuration of stem andbranches, as the result of considerable analysis of structure of tree. The
result indicates that there is no DEM area in case of measurement of conifer
forest by LiDAR.
100.00%25years

90.00%

35years
45years

80.00%
Ratio of creation of DEM

60years
70.00%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
0

2

4

6

8

10

Pulse density (N/m2)

Figure 4: Relationship between ratio of creation of DEM and pulse density.

Effect of Crown Properties of Chamaecyparis Obtusa Tree in Japan for DEM Creation

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October 2009, Incheon, Korea

300

1 (N/m2)

Number of points cloud on the gournd

2 (N/m2)250

4 (N/m2)
8 (n/m2)

200

150

100

50

0
0

1

2

3

4

5

6

Radius from center geographical position of tree (m)Figure 5: Relationship between number of points cloud on the groundwithin a circle with specific radius

4. CONCLUSIONSThis paper demonstrates that there is potential of estimating no creation areaof DEM for analysis from the LiDAR simulation. In particular, this work
provides the foundation for creation of DEM under forested area. Under
trees, it is difficult to create DEM due to an effect of stem and branches
around main stem. This study indicates that pulse density should be high toincrease potential of DEM creation.

REFERENCES
Endo, T., 2009. A study on new analytical method by LiDAR for forest
observation, PASUCO technical exhibition, Tokyo, 16 June, 2009.
Hirata, Y., 2004. The effects of footprint size and sampling density inairborne laser scanning to extract individual trees in mountainous terrain,
International Achieves of Photogrammetry, Remote Sensing and Spatial
Information, XXXVI-8/W2, 102-107.
Forestry Agency Statistics,
http://www.rinya.maff.go.jp/j/kouhou/toukei/index.html , accessed on 25
August 2009.

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New Technologies for Urban Safety of Mega Cities in Asia

SIMULATION OF EXPLOSION MODEL WITH
GIS/RS DATA IN HILLY URBAN AREAS
EUNMI CHANG
Korean GeoSpatial Information and Communication, Korea
emchang21@gmail.com
HYUNGSUK KIM
Korean GeoSpatial Information and Communication, Korea
kimhs@ksic.net

ABSTRACT
Traditional Explosion Simulation studies assumed the flat
environment and distance from the starting site have been regarded as amain parameter, so real GIS data and satellite data have not usedfrequently. Not only for the visualization but the actual estimation ofdamaged areas on real site, KOMPSAT 3, satellite imagery with 0.7meter
resolution and detailed digital elevation data with less than 1 meter weremodified and converted into Industrial Disaster Simulation System.
Virtualization technology, such as SEDRIS standard, was adopted to set theobject for terrain characteristics such as height, materials, and year of
established and modified. All the data on the terrain objects were obtained
through the Digital Terrain Map and sensor value of satellite imagery data.
Mega City with hilly mountainous areas, explosions in chemical plant
may result in high casualty and loss in SOC. We used simple explosion
model which is named as “TNT Equivalent Model” and applied the model
for real GIS data. And then we got the result of representing the effect ofreal terrain data. In this research, we just focused on the integration of GIS
and Remote Sensed data which have been collected for other purposes byusing simple explosion model. The simulation result with API of SEDRIS
viewer could give an outreach program for disaster prediction or estimationand preparedness for the managers of plants and city officers.
1. INTRODUCTION
An increase in oil and gas plants caused by development of process industry
have brought into the increase in use of flammable and toxic materials in thecomplex process under high temperature and pressure. There is always
possibility of fire and explosion of dangerous chemicals, which exists as
raw materials, intermediates, and finished goods whether used or stored in
the industrial plants. The scales of industrial and natural disasters in recent
ten years are illustrated in Figure. 1.

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October 2009, Incheon, Korea

Figure 1: amount of damage in recent ten years
It shows industrial disaster was growing and its scale is as much as big. So,corresponding disaster prevention policy is needed. There are many cases ofhuman cause and its damage range is predictable. So it is able to establish
corresponding plan by prediction of accurate scale. Because past prevention
policy of disaster was established without systematic analysis and survey,
engineering simulations only performed. For simulation of industrial
disaster, Phast Professional, commercial software, or CAMEO, EPA andNOAA made, has used in general condition. And the researches are active
about relate part. But it is simple application of plain ground condition
without considering Korean terrain environment. There are the necessities
of simulation in real terrain condition.
For Quantitative Risk analyses, real terrain data is simulated by SEDRIS. To
construct the target area’s terrain model with SEDRIS, we have to combine
DEM(Digital Elevation Model) of high resolution satellite image and aerial
photograph and SEDRIS with geographic data. And apply industrial disastermodel with that result. This approach will show more accurate prediction ofdamage than past one.

2. SIMULATION METHODOLOGY OF INDUSTRIAL DISASTER
It is a UVCE which is frequently occurred explosion around chemical
instruments.
The UVCE(Unconfined Vapor Cloud Explosion) is occurred throughfollowing 4 steps.
1.
2.
3.
4.

Leaking out flammable vapor or gas
Forming flammable vapor cloud by mixing leaked material and air
Igniting flammable vapor cloud compound
Propagating flame through vapor cloud in flammable concentration

It is seldom whole or almost vapor clouds explode. Flames propagate withchain detonation in many cases. Gas react rapidly seems to explode at a time.
There are two cases Which One Flash Fire, flame propagate slowly Another
UVCE, flame propagate rapidly, so it takes place a lot of over pressure.

780

New Technologies for Urban Safety of Mega Cities in Asia

If UVCE occurred, it companies big over pressure in conditions of
turbulence flow and partial confinement or objection and explosion. In real
UVCE, explosion over pressure can be 15 psi in stagnant area but 1.5 psi in
not confinement condition. Using following equation 1, approximates themass of TNT.
(1)
where W
η
M
Ec
EcTNT

= Equivalent mass of TNT[kg]= Empirical explosion yield[0.01~0.1]= Mass of flammable material released[kg]= Lower heating value of combustion of flammablegas[kJ/kg]= Heat of combustion of TNT[4500kJ/kg]

Figure 2: Overpressure due to explosions
The side-on blast overpressure at some real distance(R) of charge of mass of
TNT, result of equation 1, is found by following equation.

(2)

where R*
= Hopkinson-scaled distance[m/kg1/3]
WTNT = charge of weight of TNT[kg]R= real distance from charge [m]If the scaled distance is R* known, the corresponding side-on blast peak
overpressure can be read from the chart in Figure 2. But Figure 2 about
scalded distance vs. overpressure graph is non-linear. So regression equation
is fitted as equation 3.
(3)

Simulation of Explosion Model with GIS/RS Data in Hilly Urban Areas781

October 2009, Incheon, Korea

where P*R*

= explosion overpressure[bar]= Hopkinson-scaled distance[m/kg1/3]

Damage amount of explosion area is estimated with above equations andchart. Whole flow chart for calculating explosion quantity is following.

Figure 3: Logic Diagram for UVCE

3. CONSTRUCTION MODEL AND APPLICATION OF TERRAIN
MODEL
Accurate and unambiguous representation of environmental data is an
important part of many information technology applications.
SEDRIS(Synthetic Environment Data Representation and Interchange
Specification) permits representations of environmental data that can be
described accurately, unambiguously, and precisely.
Authoritative representations of the environment are expected to beinternally consistent and conform to physics-based principles. Furthermore,
representations of environmental data shall contain an appropriate
integration of terrain, ocean, atmosphere, and space domain data about aregion of interest. SEDRIS supports the representation of the physical aswell as the abstract aspects of each environmental domain. In addition, theactual reference objects being modeled or described can be either natural(e.g., some region of the Earth) or some constructed object. This lattercapability is important in applications that evaluate the characteristics andperformance of constructed objects with respect to environmental effects
and impacts, prior to production (e.g., testing and evaluating land, water, air,and space vehicles).
SEDRIS also supports the representation of 3D models, including various
articulations required to convey general system design characteristics, as782

New Technologies for Urban Safety of Mega Cities in Asia

well as data representation in the environmental domains of: Terrain, Ocean,Atmosphere, and Space.
A representation of the terrain domain includes data on the location andcharacteristics of a planetary surface, natural and permanent or semipermanent constructed features, and related processes including seasonaland diurnal variation.

Figure 4: SEDRIS Environment domains
SEDRIS relies on its five core technology components. These are the
SEDRIS Data Representation Model (DRM), the Environmental Data
Coding Specification (EDCS), the Spatial Reference Model (SRM), theSEDRIS interface specification (API), and the SEDRIS Transmittal Format(STF).
Three of these (DRM, EDCS, and SRM) are used to achieve theunambiguous representation of environmental data. The combination ofthese three core components provides the mechanism for description ofenvironmental data. In some respect, this capability within SEDRIS can beviewed as analogous to a language for describing data about theenvironment. The DRM, the EDCS, and the SRM enable us to capture andcommunicate meaning and semantics about environmental data. The
SEDRIS API and the STF allow the efficient sharing and interchange of theenvironmental data represented by the other three components. In thefollowing, each of these five components is briefly described.

4. SIMULATION RESULT
For performing simulation, explosion conditions are following.
Explosion in the LPG replenishment station
case,
Explosion Type : UVCE
Explosion Material : LPG(Butane:C4H10)
Released Mass : 10kg
Empirical explosion yield : 0.04(4%)

Simulation of Explosion Model with GIS/RS Data in Hilly Urban Areas783

October 2009, Incheon, Korea

Estimation result of UVCE model with plain terrain condition is illustrated
in Figure 5. It shows explosion effect range is drawn by concentric circle.
This result is obtained by not reflecting the geographical information in
UVCE model. In plain ground case, a concentric circle indicating thepressure becomes a concentric circle.
If the explosion is simulated with three-dimensional model and nonexistence of objection condition and reflecting the geographical informationfrom DEM in UVCE model for hilly area, simulation result is represented
by ellipsoidal shape according to the geography of the area. It is illustrated
in Figure 6. This is the more correct result than application of plain groundand this can be used in planning for emergency fire escape.

Figure 5: Explosion effect for plain Figure 6: Explosion effect for hilly
area
ground

5. CONCLUSION
Today, not only the frequency of industry disaster has increased but also thescales of the disaster have enlarged and broaden due to the recent industrial
development and constantly occurring accidents. Yet there is no disasterprediction system at present which is pointed out as the limitation to copewith disasters in scientific measures. Therefore, it is suggested to develop adisaster prediction system suitable for domestic terrain condition to establisha scientific disaster management system and an effective driving force indisaster prevention strategy and a disaster measure system. As a mean ofstatus analysis study to predict disaster, this paper focuses on the applicationof the hilly area.
The result of the risk prediction made the two-dimensional damage
prediction into a three-dimensional one. In other words, it can be used to
predict possible damages more accurately and to make it possible toestablish strategies for emergency evacuation. But on the other hand, due tothe diversity of data on various subjects and in many different types, it ispointed out that standardization of the data types is highly required along

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with the articulated cooperation system for proper application for the sake offuture damage prediction.

REFERENCES
AIChE-CCPS : Guidelines for Chemical Process Quantitative Risk Analysis,
New York (1989)
Brasie, W. C., Simpson, D. W. : Guidelines for Estimating Damage
Explosion, Dow Chemical Co., Midland. Mich (1990)
HyungSeok Kim : Study of 3D terrain information for risk assessment. In:
2008 fall academic Symposium on Korean Institute of Chemical Engineers
Meetings, Busan(2008)
Kees van Wingerden : Predicting Blast Overpressure Caused by Vapor
Cloud Explosions in the Vicinity of Control Rooms. Process Safety Progress,
Vol. 18 , No. 1, pp 17-24 (1999)
SEDRIS – Environmental Data Representation & Interchange :http://www.sedris.org

Simulation of Explosion Model with GIS/RS Data in Hilly Urban Areas

785

IDENTIFICATION OF
GROUNDWATER POTENTIAL ZONES IN
KEN-BETWA RIVER LINKING AREA
USING REMOTE SENSING AND GIS
RAM AVTAR1, H. SAWADA1, S. MUKHERJEE2, C. K. Singh2
1
Institute of Industrial Sciences, The University of Tokyo, Japan
2
School of Environmental Sciences, Jawaharlal Nehru University,
New Delhi, India
ram@iis.u-tokyo.ac.jp
ABSTRACTThe objective of this study is to identify the feasibility of the KenBetwa River link project in aspect of groundwater availability. This is doneby studying the groundwater potential zonation (GWPZ) map of the project
benefited area. Remote sensing data with other ancillary data in geographic
information system (GIS) is useful to delineate GWPZ map of Ken-Betwa
River linking area. Various thematic maps such as geomorphology, land
use/land cover, lineament, drainage, soil, and slope were generated fromLandsat (ETM+) satellite data of the year 2005, survey of India (SOI)
topographic sheets, existing maps and SRTM DEM data. These themes wereoverlaid to generate GWPZ map of the area by using ranking and weighttechniques. Groundwater level maps of the area were also generated byusing interpolation of groundwater level data of the monitoring wells. The
groundwater fluctuation during the monsoon season is due to the recharge
from rain water. The GWPZ map of the area delineated from the overlay
shows a strong correlation with the groundwater level maps. The final mapof the area shows different zones of groundwater prospects, viz., good
(5.22% of the area), moderate (65.83% of the area) poor (15.31% of thearea) and very poor (13.64% of the area). This shows that supply of water
through the link will be useful for the surrounding area but sometimes it willcause some problems like water logging.
1. INTRODUCTION
Water is the most precious and commonly used resource in nature, both
surface and under groundwater. Groundwater is a dynamic resource which
varies temporally as well as spatially. In a developing country like India
where we have acute water problem, both in drinking and irrigation water,
the nature, source and the availability of groundwater should be thoroughly
studied and evaluation of groundwater potential is a very important issue.
Overexploitation of groundwater or monsoon failure results into inadequate
recharge and depletion of groundwater table will cause hydrometeorological hazards such as drought which is more frequent in the recent
history of Bundelkhand (Bhagwat I. P., 2008).

787

October 2009, Incheon, Korea

The Ken-Betwa Link Project (KBLP) involves connecting the Ken andBetwa Rivers through the creation of a dam, reservoir, and canal to provide
storage for excess rainfall during the monsoon season in the upper Kenbasin and deliver this water for consumption and irrigation purposes to theupper Betwa basin (NWDA, 2007). The thematic layers like geology,
geomorphology, lineament, drainage, soil type, land use/land cover, andslope were analyzed in GIS environment to generate GWPZ map of thestudy area (Krishnamurthy et al. 2000, Murthy 2000). Several studies(Jaiswal et al. 2003, Wolski and Gumbricht 2003) have demonstrated theuse of remote sensing for groundwater zonation displaying the potential andlimitations of this tool. Saaty (1994) proposed one of the most accepted
quantitative method for assigning relative weights and rates for various
themes is based on the multi-criteria evaluation for decision making. In thisstudy an attempt was made to utilize similar method to identify feasibility of
Ken-Betwa River linking project.
2. STUDY AREA
Most part of the study area lies in Bundelkhand which is divided between
the states of Uttar Pradesh (UP) and Madhya Pradesh (MP). The commandarea of this link is bound between latitude 24040’ E, 78060’N to 25065’E andlongitude 78040’N, 25030’E to 80000’N (figure 1). It covers approximately
61,750 km2 of area spread in 17 administrative blocks.
Bundelkhand generally experiences a semi-arid climate, though this ishighly variable depending on the region and the time of year. Indeed, thearea is notorious for experiencing droughts in summer and disastrous floods
during the monsoon. The monsoon brings over 90% of the annual rainfall
between the months of June to September, with the highest precipitation
occurring in July and August. The average annual rainfall varies from 75 to
125 cm. The dry plains in the north usually receive less rainfall while thesoutheast benefits from more. The area has average annual maximum andminimum temperature of 44.20C and 6.70C.
2.1

Geology of the area

The area contains three major groups of rock with high uncertain
ages: the Bundelkhand complex (older than 2600 Million years) the Bijawargroup (2600-2400 Million years), Vindhayan super group (1400-900
Million years) as shown in figure 2. The study area is predominantly madeup of Bundelkhand Granite complex belonging to Bundelkhand Group. The
Bijawar group of the area consists of terrigenous sequence of basal
carbonates and shales with green schists or pillow basalts, chloritic shales,
ferruginous quartzites and banded iron formations. Vindhayan super groupare represented by red to greyish-white, medium to fine grained, compact
and highly jointed sandstones all over the Vindhayan basin (Mallet, 1869).

788 Identification of groundwater potential zones of Ken-Betwa River linking area using Remote Sensing and GIS

Figure 1: Location of the study area

Figure 2: Geology of the area

3. MATERIALS AND METHODS
The methodology adopted for this study is given in the following flow chart(fig.3). Each thematic map was assigned a weight depending on its influenceon the storage and movement of groundwater. The weight and rank of eachlayer is given in the table 1. The scored maps were overlaid by using spatial
analyst tool of ArcGIS 9.3. The resultant map was classified into good,moderate and poor zones. The results were validated by using groundwaterlevel data of the central groundwater board (CGWB).

Figure 3: Methodology adopted for Groundwater potential zonation map
4. RESULTS AND DISCUSSION
4.1 Geomorphology of the area
Geomorphologically, the area depicts both erosional anddepositional landforms as shown in figure 4. Geomorphology was assigned
highest weight because it has a dominant role in the movement and storageof groundwater in the study area (Thomas B. C., 2009).
Identification of groundwater potential zones of Ken-Betwa River linking area
using Remote Sensing and GIS

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October 2009, Incheon, Korea

•

•
•
•
•
•

Erosional hills: This represents the remnants of oldest planation surface
marked by domes and ridges of Bundelkhand granite and gneiss.
Because of high slope and relief they are not suitable for groundwater
exploration.
River channel: Ken, Betwa and Yamuna are main rivers along withnumber of tributaries, transporting a heavy amount of silt, clay and sand.
These are considered as good zones for groundwater.
Flood Plain: These are comparatively low-lying area, close to the river.
The flood plain deposits are developed at the constructive side of river
channels. They are considered as good zones for groundwater.
Alluvial plains: The porosity and permeability of the alluvium are very
high so they are considered as good zones for groundwater.
Ravines: Most of the area of River Betwa, Dhasan and some area of
Ken is covered by ravines. Ground water possibilities become less due
to high run off and its impermeable nature.
Pediments: Pediments are most prevalent in very arid environments.
These are considered as poor to moderate for groundwater.

4.2 Lineament map of the area
Lineaments are the manifestation of linear features can play a majorrole in identifying suitable sites for groundwater recharge (Krishnamurthy J.,
2000). Lineaments on the surface have been identified early as conduits forgroundwater flow in fractured aquifers and hence targeted for locatingproduction wells (Meijerink 1996). The purpose of the lineament density
analysis is to calculate frequency of the lineaments per unit area
(Greenbaum, 1985). Orientations of the lineaments are usually analyzed byrose diagrams. The rose diagram indicates that the most dominant fault
direction is N30-40 degree and S210-220 degree (fig.5a, c). The lineament
trends are predominantly along NNE-SSW, NNW and SSE. The lineamentdensity is high in the southern and central part of study area (fig. 5b).
Lineaments play important role in groundwater recharge in hard rockterrains (Koch and Mather 1997). Lineament-length density (Ld) is the total
length of all delineated lineaments divided by the total area underconsideration (Greenbaun, 1985):
i =n

Ld = ∑ Li
i =1

A

(m-1)

i =n

where ∑ Li = total length of all lineaments (m) and A= area (m2).
i =1

4.3 Slope map of the area
Slope is a measurement of steepness from the ground surface. The
slope map was generated from the DEM using Arc GIS 9.3 spatial analysis
tool. Most parts of the study area have slope within the range of 39 to 57
degree. Southern part of the area exhibits steeper slope, where as thenorthern parts are associated with lower slopes. Alluvial region in the790 Identification of groundwater potential zones of Ken-Betwa River linking area using Remote Sensing and GIS

northern part shows that lower slope is good for groundwater recharge while
hilly region of southern part shows that steeper slope is not good forgroundwater recharge (fig. 6). The slope of the area has a large impact on
the amount of water infiltration into the ground and amount of water lost as
run off.
4.4 Soil map of the area
The climate, physiography and geology characterize soil and play
important roles in groundwater recharge and run-off. The water holding
capacity of the area depends upon the soil types and their permeability.
Basically, the soil in this region is often divided into Clayed loam, Sandy
loam, Loamy and Loamy sand. On the basis of soil texture, most of the partis covered by loamy soil (figure 5). The soil with poor water holding
capacity like sandy loam is good for groundwater recharge.

Figure 4: Geomorphology map

Figure 5(a): Lineament map
Rose Diagram
0

N
W

E
S

270

90

Rose - lineaments.shp

180

Figure5 (b): Lineament density map

Figure5(c): Rose diagram

4.5 Drainage map of the area
Drainage map of the study area was generated from the vectorization of
topographic sheet as well as satellite imagery, representing the network ofmain streams in the catchments, followed by the tributaries up to the lastorder. The drainage pattern in the area was dendritic, pinnate type (fig.8).
Drainage density is the ratio of the total length of the stream to the area ofthe drainage basin. The southern part of the basin is associated with very
Identification of groundwater potential zones of Ken-Betwa River linking area
using Remote Sensing and GIS

791

October 2009, Incheon, Korea

high drainage density. About 40% of the area upstream of the ganagu weirshows medium drainage density. Some parts of the western and southeastern of the catchment show low drainage density, this is due to highamount of vegetation and permeable nature of the soil (fig.9). Higher thedrainage density lower is the infiltration and faster is the movement of thesurface flow so less recharge (Pachauri et al. 1998).
4.6 Land use/Land cover map of the area
The land use/land cover map was generated by using unsupervisedclassification. Landsat ETM+ satellite data of year 2005 and topographic
maps were used to prepare the land use map of the study area through image
classification procedure. On this basis, the whole area was classified into 10
categories viz. water, dense forest, built up, current fallow/agricultural land,
water logged, degraded forest, land with scrub, bare exposed rock, fallow

Figure6: Slope map

Figure 8: Drainage network map

Figure7: Soil map

Figure 9: Drainage density map

792 Identification of groundwater potential zones of Ken-Betwa River linking area using Remote Sensing and GIS

Figure 10: Land use/land cover map of the study area
land, and land without scrub (fig.10). Land use/land cover effectevapotranspiration, surface run-off, and groundwater recharge. Waterlogged
area is good for groundwater recharge and fallow land is poor for it(Chowdary V. M., 2008).
4.7 Depth to water level
Ground water level data of 124 observation sites was collected fromCentral Ground Water Board (CGWB) for the year 1999 to 2004. The
observation points originally expressed as geographic coordinates wereconverted to UTM projection system for interpolation (fig.9). FinallyInterpolation of the ground water level was done by using Splineinterpolator in Arc View 3.2a.
In the study area, as the precipitation is concentrated mainly inmonsoon season, depth to ground water is generally reduced during
monsoon and post-monsoon, whereas it gets deepened during pre-monsoon
because discharge rates are greater than the recharge rates. Under natural
conditions, depth to water-level is related to topography. The ground water
depth is maximum in the northern portion of the study area, and minimumin the southern portion of the study area. The magnitude of seasonal
fluctuation in water levels in response to monsoon recharge is related toaquifer porosity and storage. After recharge, the rise in water levels may begreater and sustained longer in aquifers with low permeability than in
aquifers with high permeability (Sara M. N., 2003). The range of seasonal
fluctuation generally varied from region by region of the study area,
reflecting the different hydrogeological conditions and spatial variations inrecharge rates or storage characteristics of the aquifer.
4.8 GIS modeling
These maps were superimposed on groundwater potential map andidentify the area with water scarcity and it shows correlation with thegroundwater potential zonation. The area around the rivers, alluvial plain,
low slope, low drainage density, with high lineament density is good ingroundwater prospects. The area with high slope, high drainage density, andravenous, low lineaments are poor to very poor in groundwater prospects.
The linking canal will transfer water from Ken river to Betwa river ispresent in the very poor and poor zone of the GWPZ map so it will benefit
enroute command area. This enroute command area covers Chhatarpur,
Tikamgarh, Jhansi, Hamirpur district of Bundelkhand and these districts
were severally affected by recent drought. So this link will help to solve
water scarcity problems of these districts.

Identification of groundwater potential zones of Ken-Betwa River linking area
using Remote Sensing and GIS

793

October 2009, Incheon, Korea(a) May 1999(b) August 99(c) Nov 99(d) Jan 2000(e) May 2000(f) August 00(g) Nov 00(h) Jan 2001(i) May 2001(j) August 01(k) Nov 01(l) Jan 2002(m) May 2002(n) August 02(o) Nov 02(p) Jan 2003(q) May 2003(r) August 03(s) Nov 03(t) Jan 2004

Figure 11: Interpolation maps of groundwater level

Figure 12: Groundwater potential zonation map of the area

794 Identification of groundwater potential zones of Ken-Betwa River linking area using Remote Sensing and GIS

Table1: Thematic map weight, feature and ranking for GWPZ
Theme
WeightFeatures
Geomorphology

5Lineament density

4

Slope

3

Soil Cover

3

Drainage Density

2

Land use/ land cover1

Flood plain
Ravines
Pediment
Erosional hills
Alluvial plainHigh
MediumLow
Very low
>72
57-72
39-57
14-39
<14
Clayed loam
Sandy loam
Loamy
Loamy sandVery High
High
MediumLow
Very Low
Dense forest
Land with scrub
Agricultural land
Degraded forest
Land without scrub
Fallow land

Rank
5
1
2
2
3
4
3
2
1
1
2
3
4
5
1
4
2
3
1
2
3
4
5
1
2
3
3
4
4

5. CONCLUSION
In the developing country like India, with weak infrastructure, lowaccessibility and data scarcity, utilization of remote sensing and GIS is agood tool for water resource management. GIS plays an important role inintegrating all the data to generate groundwater potential zonation. This isuseful in the study of feasibility of the Ken-Betwa River linking. The
GWPZ map of the area shows a good correlation with the groundwater level
data. This map will helps in planning strategies for effective managementand distribution of water resources. The change in land use/land cover is the
major threat to groundwater potential. In ancient time Bundelkhand area hadlots of natural water bodies, which were a good source for groundwater
recharge but due to population growth they disappeared. The water demand
will increase with the increase in population. To solve this problem, river
linking is a good solution. But the alternate techniques like rainwater

Identification of groundwater potential zones of Ken-Betwa River linking area
using Remote Sensing and GIS

795

October 2009, Incheon, Korea

harvesting, infiltration pits, reuse, recycle etc. are much more cost effective
than such a huge project like linking river.
REFERENCES
Bhagwat I. P. 2008, Drought and Drinking Water Crisis in Bundelkhand, Water
aid India, September 2008.
Chowdary V.M., Vinu Chandran R., Neeti N., Bothale R.V., Srivastava Y.K.,
Ingle P., Ramakrishnan D., Dutta D., Jeyaram A., Sharma J.R. and Singh R.,
2008, Assessment of surface and sub-surface waterlogged areas in irrigationcommand areas of Bihar state using remote sensing and GIS. Agricultural
Water Management, Volume 95, Issue 7, pp. 754-766.
Greenbaum, D., 1985, Review of remote sensing applications to groundwater
exploration in basement and regolith, Brit Geol Surv Rep OD 85/8, 36 pp.
Jaiswal, R.K., Mukherjee, S., Krishnamurthy, J., and Saxena, R., 2003, Role ofremote sensing and GIS techniques for generation of groundwater prospectzones towards rural development: an approach. International Journal of
Remote Sensing, 24 (5), 993-1008.
Koch, M. and Mather, P. M., 1997, Lineament mapping for groundwater
resource assessment: a comparison of digital Synthetic Aperture Radar (SAR)
imagery and stereoscopic Large Format Camera (LFC) photographs in the Red
Sea Hills, Sudan. International Journal of Remote Sensing, 18, 1465-1482.
Krishnamurthy, J., Mani, A., Jayaraman, V., and Manivel, M., 2000,
Groundwater resources development in hard rock terrain: an approach using
remote sensing and GIS techniques. International Journal of Applied Earth
Observation and Geoinformation, 2 (3-4), 204-215.
Mallet, F. R. (1869), “Vindhayans of central provinces”, Memoir Geological
Survey of India, Vol. II, Part. I.
Meijerink AMJ, 1996, Remote sensing applications to hydrology: groundwater.
Hydrological Science Journal 4:549–561
Murthy, K.S.R., 2000, Groundwater potential in a semi-arid region of Andhra
Pradesh: a geographical information system approach. International Journal of
Remote Sensing, 21, 1867-1884.
National Water Development Agency 2007, Ken-Betwa Link Project
Feasibility Report,
Pachauri, A K, Gupta, P V, and Chander, R., 1998, Landslide zoning in a partof the Garwal Himalayas”, Environmental Geology, Vol. 36, No. (3-4), pp.
325-34
Saaty, T.L. 1994, Highlights and critical points in the theory and application of
the analytic hierarchy process, European Journal of Operational Research, Vol.
74 pp.426-47.
Sara M. N., 2003, Site assessment and remediation handbook. Lewis publishers.
Thomas B. C., Kuriakose S. L. and Jaydev S. K. 2009, A method forgroundwater prospect zonation in data poor areas using remote sensing and
GIS: a case study in Kalikavu Panchayath of Malappuram district, Kerala,
India; International Journal of Digital Earth, Vol. 2, No.2, June 2009, pp. 155170.

796 Identification of groundwater potential zones of Ken-Betwa River linking area using Remote Sensing and GIS

ESTIMATION OF LAND SURFACE WATER
COVERAGE (LSWC) WITH
OPTICAL VS. MICROWAVESSHUMON MORI, WATARU TAKEUCHI and HARUO SAWADA
Institute of Industrial Science, The University of Tokyo
morishumon@gmail.com

ABSTRACTThis research focuses on estimation of land surface water coverage byusing AMSR-E and MODIS sensors. The main point in this study is tocalibrate the two data, NDPI (normalized difference polarization index) and
LSWC (land surface water coverage) obtained by AMSR-E and NDWI
(normalized difference water index) of MODIS respectively and finally we
produced daily land surface water coverage map.

1. INTRODUCTION
In recent years, overpopulation, human activities and global warming
are causing hydrological problems such as water shortage, increase of flood
disasters. Then water cycle monitoring at different scales, from small
catchments to large river basins, is important for drought analysis, crop
yield forecasting, irrigation planning, floods and forest fire prediction(Teodosio, 2005).
In the past, many satellite techniques have been proposed to remotely
map flooded areas and to monitor hydro-geophysical parameters. The main
advantage of satellite remote sensing is the capability of monitoring large
areas in temporal-spatial continuous record. Previous satellite techniques formonitoring the water cycle exploit the microwave data advantages.
Microwave remote sensing can be used quite effectively to study seasonal
inundation and flooding of rivers and swamps because microwave isunrestricted by cloud cover and can provide information about suchhydrologic variables as soil wetness, seasonal inundation, vegetation, snow,
wetness and its water equivalent and rainfall(Bhaskar, 1991).
In this study we used two sensors: AMSR-E as microwave sensor and
MODIS as optical sensor. AMSR-E is a microwave sensor and its spatial
resolution is in scale of kilometers, not high resolution, but it can observe
the land surface with low cloud interruption (that means high temporal
resolution). On the other hand MODIS sensor is an optical infrared sensor
and its spatial resolution is in scale of hundreds meters (high spatial
resolution) but its observation is frequently interrupted with cloud. In order
to investigate the water cycle of the ground, high spatial-temporal resolution
is required.
In previous research, Takeuchi (2006) focused on that optical andmicrowave sensors are in trade off relationship between spatial resolution797

October 2009, Incheon, Korea

and cloud interruption, then combined utilization of AMSR-E and MODIS
has been conducted to enable us observing the water cycle with high spatialtemporal resolution. Takeuchi found the correspondence of water cycle
between AMSR-E and MODIS. The data used were two indices, called
NDPI (normalized difference polarization index) and NDWI (normalized
difference polarization index) obtained from AMSR-E and MODIS
respectively.
The objective of this study is to estimate land surface water coverageby using AMSR-E and MODIS sensors. In this study, the target area islocated in Bangladesh, known as severe flood area. The footprint size of
AMSR-E is 10 square km and that of MODIS is 2 km. It means that one
footprint of AMSR-E includes 25 (5×5) footprints of MODIS. Then we
counted the number of inundated footprints within these 25 footprints andcalculated the land surface water coverage (LSWC [%]).
Here, AMSR-E gives us the index NDPI and MODIS gives us the
LSWC. After getting these two data, NDPI and LSWC, we analyzed therelationship between them. This relationship enables us to estimate physicalquantity - LSWC [%] everyday from index NDPI according to the feature of
AMSR-E. By exploiting the relationship, finally we produced AMSR-E
LSWC map.

2. METHODOLOGY
2.1. Flowchart to produce LSWC distribution map with AMSR-E and
MODIS
Figure 1 shows a flowchart to produce land surface water coverage(denoted as LSWC) distribution map by combining AMSR-E and MODIS.
AMSR-E10km mosaics(2006, 365 scenes)

NDPI

MODIS
2 km mosaics(2006, 8 day composite,
46 scenes)

NDWI

Calibrating
NDPI and LSWC [%]with logistic function.
LSWC = F(NDPI)LSWC [%]
25 pixels = 5×5

Mapping the LSWC distribution
by using AMSR-E NDPI

Figure1: Flowchart to produce LSWC distribution map by combining AMSR-E andMODIS
AMSR-E data was obtained from National Snow and Ice Data Center(NSIDC) in United States of America, and a series of preprocessing was
carried out including radiance calibration, geometric correction, spatial
mosaic and subset. Normalized difference polarization index (NDPI) was
computed as shown in Equation (1).

NDPI =

Tv − Th
Tv + Th(1)

New Technologies for Urban Safety of Mega Cities in Asia798

Tv : 36.5 GHz brightness temperature vertical
Th : 36.5 GHz brightness temperature horizontal
MODIS data rebuilding was carried out by Linlle-University group(Dr. Louis Gonzalez, personal communication) based on NASA’s 8-day
global mosaic composite product (MOD09A1). The idea is to remove
clouds by spatio-temporal filtering technique on a footprint-basis processing.
Normalized difference water index (NDWI) was computed as shown inEquation (2).

NDWI =

VIS − SWIR
VIS + SWIR

(2)

VIS : Reflectance of visible (630 nm, channel 1)
SWIR : Reflectance of short wave infrared (1620 nm, channel 6)
2.2. Study area
Figure 2 shows an area of interest in this study highlighted by red
square, centered at latitude 54-17`59, 95”N, longitude 90-52`0.20”E. The
area is 10,000 square kilometers (10x10 footprints) covered by seasonal
dynamics of open water, natural wetlands and paddy fields. In this study,
above ground vegetation contribution is neglected.

Figure2: Area of interest in this study is highlighted by red square, centeredat latitude 54-17`59, 95”N, longitude 90-52`0.20”E and the area is 100
square kilometer known as open water area.
2.3. Setting the inundated footprint thresholdIn this study land surface water coverage is strongly dependent on theinundated threshold. To estimate the precise inundated threshold we build
the global land coverage histogram by utilizing MODIS NDWI images.
After that, we simulated the histogram’s curve behavior with Gaussianfunction:f ( x) =a
2π c 2exp(−( x − b) 2)
2c 2

Estimation of land surface water coverage (LSWC) with optical vs. microwaves

(3)

799

October 2009, Incheon, Korea

The parameter ‘a’ expresses the height of the curve’s peak and ‘b’expresses the center of curve’s peak and ‘c’ controls the width of peak. In
this study we simulated 36 NDWI histograms.
Then we processed 3 steps:
First step is to classify the part of histogram such as vegetation, soil,
and mixture of water and soil.
Second step is to confirm the dependence of temporal series of thethreshold by verifying the fluctuation of the peaks.
Third step is to classify the distribution of inundated area in order to
set the inundated threshold more precisely.
2.4. LSWC (Land Surface Water Coverage)
Figure 3 shows a schematic diagram between AMSR-E and MODIS
footprints. One footprint of AMSR-E (10 square km) corresponds to the 5x5
block of MODIS footprints.
10km = 2[km/footprint] ×5[footprint]

10km
Inundated footprints

Total = 5×5 = 25 footprints(b) MODIS NDWI(a) AMSR-E NDPI

Figure 3: Spatial correspondence between AMSR-E and MODIS.
LSWC between AMSR-E and MODIS was estimated by following thethree steps:
1. To select the threshold of MODIS NDWI images to distinguish between
inundated and non-inundated footprints aided by histogram curve.
2. To produce the inundated distribution map in 2 km and spatiallyaggregate the inundated distribution map 2 km into the fractional coverageof land surface water coverage in 10 km (MODIS LSWC).
3. To find out the relationship between AMSR-E NDPI and MODIS LSWC.
Logistic function as shown in Equation (4) is expected to fit well between
those (Takeuchi, 2006). The coefficients a, b and c are estimated by using
the least squares method.

LSWC =a
1 + b ⋅ exp(−c ⋅ NDPI )(4)

3. RESULTS
3.1. Spatial correspondence between AMSR-E NDPI and MODISNDWINew Technologies for Urban Safety of Mega Cities in Asia

800

Figure 4 shows comparison of MODIS NDWI 2 km, MODIS LSW
map 2 km, MODIS LSWC 10 km and AMSR-E NDPI 10 km. Brighter
footprints indicate high abundance of inundated area.
MODIS NDWI 2km

MODIS LSW map 2km MODIS LSWC 10km

AMSR-E NDPI 10km

Jan

Apr

Oct

Figure 4: Comparison of MODIS NDWI 2km, MODIS LSW map 2km,
MODIS LSWC 10 km and AMSR-E NDPI 10km. Brighter footprints
indicate high abundance of inundated area.
3.2. Select the inundated threshold
Figure 5 shows a MODIS NDWI histogram in 2006 characterized by
4 peaks including vegetation (peak1), soil (peak2), mixture of soil and water(peak3), and water and snow (peak4).
2kmMODIS NDWI global histogram
140000
peak1 (vegitation)

Number of pixels/25

120000

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Averagepeak 4(water and snow)

10000080000
peak 2 (soil)

60000
40000

peak 3 (soil and water)
20000
0
0

50

100

①

150
MODIS NDWI

②

200

③

250

④

Figure 5 : MODIS NDWI histogram in 2006

Estimation of land surface water coverage (LSWC) with optical vs. microwaves

801

October 2009, Incheon, Korea

In first step, we classified the peak1, 2 and 3 by matching theGaussian function with them and we demonstrated approximately their land
cover type according to NDWI values. Then, the result was that peak1
represents the vegetation area, that peak2 represents the soil area and thatpeak3 represents the mixture of soil and water area. The results are
summarized in Table 1 and in Figure 6.

Table 1: details of 3 peaks

Peak1
Peak2
Peak3

averaged center of peak

S.D. of peak

S.D. of center

83.0
100.3
126.8

5.2
7.8
3.3

0.7
1
1.5

Figure 6: Global NDWI histogram mapping. The green footprints whose
range o f [78, 81] shows vegetations, The brown footprints whose range of[92, 108] shows soils and the yellow footprints range of [123, 130].
In second step, we found the slight-fluctuation of the peaks as shownin Table 1 and in Figure 5. Therefore we suggested the independence of theinundated threshold on temporal series.
In third step, we investigated the inundated range, NDWI = [121, 255],
to determine the precise inundated threshold by classifying the range to 4
areas, NDWI = [121, 136], [137, 178], [179, 239], [240, 255], as mentioned
in the above Figure 5. The results are shown in the figure 7- (b).
Then we comprised the NDWI maps with MODIS visible map in
Bangladesh and we determined that inundated threshold=121 represents theinundated areas most precisely as shown in MODIS visible image.

New Technologies for Urban Safety of Mega Cities in Asia802

(a) MODIS visible image 20060106 as a reference(b) MODIS NDWI image 20060101 (8 day composite) red footprints
show range of [240, 255], green footprints show range of [179, 239],
cyan footprints show range of [137, 178] and white footprints show rangeof [121, 136].

Figure 7: Comparison between MODIS visible image and MODIS NDWI
image
3.3. Relationship between NDPI and LSWC
Figure 8 shows the scatter plot representing the relationship between
AMSR-E NDPI and MODIS NDWI. We averaged the data collected fromarea mentioned above and after applying least squares method we received
the following scatter plot, coefficients and standard deviation:
Relationship between NDPI and LSWC
120100

LSWC [%]

80
60

average data
average

40
20
0
0

20

40

60

80

100

120

140

-20
NDPI

Figure 8 : Scatter plot representing the relation between AMSR-E NDPI
and MODIS LSWC

803

October 2009, Incheon, Korea

Table 2 : Results of coefficients a, b, c and standard deviation after
application of least method
a
100.0
b
353.5
c
0.1
S.D.
9.7
For your attention, the data is quantized to 4%. Then, the minimum
standard error is 4 % (because MODIS image has 25 footprints in 10 square
km area and then minimum scale of data is 4%).
We can find that the two regression curves are modeled similarly
within the standard error 4%. Thus, we can hypothesize that theses
regression curves represent precisely the LSWC in independent on temporalseries.
3.4. Spatial correspondence between AMER-E NDPI
distribution map and MODIS NDWI LSWC distribution map

LSWC

Figure 9 shows the spatial correspondence between AMSR-E NDPILSWC distribution map and MODIS NDWI LSWC distribution map.
Brighter footprints indicate high abundance of inundated area. Although
there is high correspondence between two maps as shown, we can find alsoa few difference in some places (indicated by red circle) due to above
vegetation covers. We hypothesized that this difference is due to effects ofabove vegetation covers on microwaves and optical waves. AMSR-E using
microwaves can detect the surface water covered by above vegetation as
well as covered by cloud although MODIS using optical wavelength can’t.

[%]
100

0

(a) LSWC distribution map of (b) LSWC distribution map of MODISAMSR-E NDPI
NDWI
Figure 9 : Spatial correspondence of AMSR-E NDPI LSWC distribution map with
MODIS NDWI LSWC distribution map

New Technologies for Urban Safety of Mega Cities in Asia804

3.5. Land surface water coverage curve and map
Land surface water coverage on 2006
100

Land surface water coverage [%]

90
80
70
60
50

LSWC

40
30
20
10
0
1-Jan

2-Mar

1-May

30-JunDate

29-Aug28-Oct27-DecFigure10: Land surface water coverage curve in 2006 at Bangladesh.

[%]
100

0

January

February

March

April

May

June

July

AugustSeptember

OctoberNovember
DecemberFigure 11: land surface water coverage map at Bangladesh in 2006.

Estimation of land surface water coverage (LSWC) with optical vs. microwaves

805

October 2009, Incheon, Korea

Figure 10 and 11 shows LSWC curve (at location indicated bycircle in Figure 11 on January) and maps respectively at Bangladesh
monitored by AMSR-E. The brighter footprints indicate high abundance ofinundated area in unit of water coverage [%]. Due to AMSR-E’s hightemporal resolution and non-cloud interruption ability, we can produce
LSWC map for everyday.
4. CONCLUSION
In this study we built the NDWI histogram in global scale by MODIS
8-day composite data and we classified the main 3 peaks to assume thewater-soil mixture NDWI range. Then, we classified more precisely thewater NDWI range. Finally, we succeeded to hypothesize the inundated
threshold with comparison of MODIS visible image.
Based on the threshold we processed the sub-footprint analysis in
10,000 square km open water area, and then we modeled the logistic
regression curve by using 100 points data of this object area.
By comparing with two days regression curve, we found that theirdifference distance is closely 4% (the our data is quantized to 4% then theminimum standard error is 4 %) then we arrived to the conclusion that ourlogistic regression curve represent precisely and independently of temporalseries Land Surface Water Coverage in open water area..
Finally we produced the LSWC map monitored by AMSR-E. In thisstudy we focus on only open water area. Then for the future work we needto investigate influences of above vegetation cover on microwaves andvisible infrared waves to improve and apply the logistic regression curve forAmazon or other similar area and we should confirm the availability for
application.
REFERENCES
Wataru Takeuchi, Daisuke Komori, Taikan Oki and Yoshifumi Yasuoka,
2006. An integrated approach on rice paddy irrigation patternmonitoring over Asia with MODIS and AMSR-E . American
geophysical union fall meeting 2006 (AGU): San francisco, USA,
2006 Dec. 5.
Teodosio Lacava, Vincenzo Cuomo, Elena V.Di Leo, Nicola Pergola,
Filomena Romano, Valerio Tramutoli, 2005. Improving soil wetness
variations monitoring from passive microwave satellite data: The caseof April 2000 Hungary flood, Remote Sensing of Environment 96(2005) 135 – 148
Suzanne J. Sippel, Stephen K. Hamilton, John M. Melack and Bhaskar J.
Choudhury, 1994. Determination of inundation area in the Amazon
river flood plain using the SMMR 37 GHz Polarization difference,
Remote Sens. Environ, 70-76, 48.
Bhaskar J., Choudhury, 1991. Passive microwave remote sensing
contribution
M. Temimi, R. Leconte, F. Brissette, N. Chaouch, 2007. Flood and soil
wetness monitoring over the Mckenzie River Basin using AMSR-E 37
GHz brightness temperature
New Technologies for Urban Safety of Mega Cities in Asia

806

REMOTELY SENSED SOIL MOISTURE
CHARACTERIZATION WITH GROUNDBASED MEASUREMENTSHYUNJIN PARK1, JIYE KANG1, JONG AHN CHUN2,MINHA CHOI1 and JONGKYU LEE1
1
Department of Civil and Environmental Engineering, Hanyang University
hydro, newjiye, mchoi, leejk@hanyang.ac.kr
2
U.S. Departement of Agriculture ARS
jongahn.chun@ars.usda.gov

ABSTRACT
Soil moisture is one of the most important key physical parameter inhydrologic processes. During past decade, remote sensing instruments havebeen widely used to provide mean surface soil moisture at large spatial
scale because conventional ground based measurements are not always
available and take time and cost. In this study, Soil moisture extracted from
Advanced Microwave Scanning Radiometer E (AMSR-E) were comparedwith ground based measurements and water surface elevation of nearby
station in a watershed scale in Korea.
Both soil moisture products from the AMSR-E and ground based stations
were also examined whether the data has statistical correlations withmeasured water surface elevation for a watershed in the central Korea. The
tendency between ground based soil moisture and water surface elevation
was identified. Two factors were formed natural logarithm function andshowed comparatively close correlation.
This type of work may provide an opportunity to examine operational utilityof the remotely sensed soil moisture products as an alternative for the
ground based measurements to understand hydrological science in Korea.

INTRODUCTION
Soil moisture is an important factor on the hydrological and ecologicalprocesses although the amount of water stored as soil moisture constitutes
only a small proportion of freshwater on the Earth (Pachepsky. 2003) Since
it is directly linked to various hydrological processes including rainfall,
infiltration, and runoff in a watershed, it is a very important key parameterof hydrologic phenomena. In addition, soil moisture associated with
evapotranspiration plays a great role in connection of the hydrologic cycle.
It is generally required to obtain soil moisture data in widespread region andto analyze them to achieve further analyses for the relation between soil
moisture data and water surface elevation time series from the watershed.
An accurate evaluation of the spatial and temporal variation of soil moisture
may be useful for improving the predictive capability of the runoff models.
However, Ground based soil moisture is tedious and takes a lot of time to807

October 2009, Incheon, Korea

collect data (Hollinger and Isard, 1994; Rombach and Mauser, 1997).
Recently, Satellite instruments are available with advanced passive
micro wave remote sensing of soil moisture. Microwave sensors have many
advantages including the ability to directly measure soil moistureirrespective of weather conditions or time (Jackson.1995). Advanced
Microwave Scanning Radiometer AMSR-E, which is instrument on theNASA EOS Aqua satellite provides global passive microwave
measurements (Njoku, 2004).
The objective of this study is to develop the relationship among soil
moisture from ground based data, remotely sensed data, and water surface
elevation at downstream. The soil moisture from flux tower wascontinuously collected in the Wangsuk watershed. The relation between soil
moisture and water surface elevation was investigated using in-situ andsatellite soil moisture data.

1. STUDY AREA
1.1 Wangsuk watershed
The Wangsuk Stream watershed in the central Korea, where theGwangneung flux tower was installed, was selected for this study. The
annual air temperature of the watershed is 12.7 and average annual rainfall
is 1381.2mm. Table 1 summarizes the geographic location, area, land use,
and SCS type. Town/dryland account for 7.0% of the total watershed area
followed by agriculture land (18.8%), forest (68.2%), Grassland (3.0%),
Bare region (1.4%), and Waters (1.5%). SCS soil type A and B are
predominant in the watershed.
Herbaceous plant, chestnut tree, white oak, pine tree and deciduoustree can be mainly found in the Wangsuk main stream. The watershed study
consists of two 25 by 25km grids identified as 1 and 2 (Figure 1).

808

New Technologies for Urban Safety of Mega Cities in Asia

Figure 1: Wangsuk watershed, network sites, Grids
Table 1: Geographic locations, area, land use, and SCS type for the
Wangsuk watershed
Grid 1
Grid 2
Coordinate of
37°57′14.76″ 37°57′14.76″ 37°42′24.84″ 37°42′24.84″
the Grid
127°01′40.08″ 127°17′20.4″ 127°01′40.08″ 127°17′20.4″
37°42′24.84″ 37°42′24.84″ 37°27′37.8″
37°27′37.8″
127°01′40.08 127°17′20.4″ 127°01′40.08″ 127°17′20.4″
Watershed area
118.44km2
83.06 km2(% of grid cell)(18.8%)(13.2%)
Land use
Type
Area (km2)% of total area
Town/Dryland
14.13
7.0
Agriculture land
37.92
18.8
Forest137.52
68.2
Grassland
6.06
3.0
Swampy land
Bare region
2.90
1.4
Waters2.97
1.5
Soil TypeSCS Type
Area (km2)% of total areaA
100.71
50.0
B
90.13
44.7
C
6.28
3.1
D
4.38
2.2

Remotely Sensed Soil Moisture Characterization With Ground Based Measurements809

October 2009, Incheon, Korea

1.2 Gwangneung site
The Gwangneung site which belongs to the Wangsuk watershed islocated in the west-central part of the Korean peninsula (37°45′25.37″N,
127°09′11.62″E). As shown Figure 2, the site of flux tower is a typicalmontane landscape of the country. Annual air temperature is 11.5 , andaverage annual precipitation is 1,332mm. The slope of the hillside is 10-20°.
Whole watershed is characterized by gneiss and schist (Kim et al, 2006).
1.3 Toegyewon gauging station
Toegyewon gauging station (37°38′50 ″N, 127°09′14 ″E) is located at
the downstream of the Wangsuk stream. The station was installed at
21.930m of elevation.

Figure 2: Location of Gwangneung flux tower and Toegyewon gauging
station. Upper point is a position of Gwangneung flux tower and lower pointis Toegyewon Gauging Station.

2. DATASETS
The study period was January 1, 2005 to December 31, 2006. During thestudy period, soil moisture data were obtained from Gwangneung flux tower(in-situ data) and satellite. Also, hydrologic data were available from
Toegyewon gauging station
2.1 In-Situ Measurements
In-situ soil moisture data are obtained from Gwangneung flux tower
which founded by KoFlux Program at Yonsei University

810

New Technologies for Urban Safety of Mega Cities in Asia(http://koflux.yonsei.ac.kr). The flux tower is continuously monitoring water,
carbon and energy fluxes. In the Wangsuk stream, in-situ soil moisture data
are obtained at a spot (Gwangneung site). In this study, we considered
Gwangneung in-situ soil moisture data as representative values of total area.
The Flux tower provides 8 different soil moisture values. The data wererecorded at every 30 minute. There are missing periods (January 1 to March
15, 2005 and December 1 to December 31, 2006) due to unexpectedmalfunction of the instruments.
2.2 Satellite Observations
The satellite data were detected by AMSR-E(Advanced Microwave
Scanning Radiometer) which is one of six sensors onboard Aqua satellite
and obtained from NASA WIST (The Warehouse Inventory Search Tool,
https://wist.echo.nasa.gov/~wist/api/imswelcome/). The AMSR-E sensor isa multi channel microwave image observation radiometer that observes
6~89GHz of microwave region. Generally, the sensor extracts various
meteorological data such as rainfall, humidity, temperature of sea surface,
and wind as well as physical earth surface data including soil moisture. Soil
moisture values that detected by AMSR-E sensor were used for this study.
The Aqua satellite makes an orbit around polar with Sun-synchronous
orbit and passes through Korea about 13:30 everyday. It provides daily dataof 25 by 25km Grids. We used the processed data which weigh thewatershed area.
2.3 Water Surface Elevation Measurements
Hydrologic data in downstream of Wangsuk watershed can beobtained from the Toegyewon gauging station. Thus, the Wangsuk
watershed runoff has immediate connection with Toegyewon water surface
elevation. Hourly water surface elevation data of the Toegyewon station
used in this study were obtained from the Han-River Flood Control Office(http://www.hrfco.co.kr).

3. RESULT AND DISCUSSIONS
3.1 Time Series Analysis
Figure 3 and figure 4 show time series graphs of the water surface
elevation, basin-averaged AMSR-E soil moisture and in-situ soil moisturefor the study area in 2005 and 2006 respectively. In these figures, somespiking of the water surface elevation was detected. The researchconcentrated on the rainy seasons (July 1 to September 30). Time series ofthem in rainy seasons are shown in figure 3 (b), (d), figure 4 (b) and (d).
The comparisons between water surface elevation and basin-averaged
AMSR-E soil moisture showed weak correlation. However, the comparisons
between water surface elevation and in-situ soil moisture showed relatively
strong correlation. As in-situ soil moisture increased, water surface

Remotely Sensed Soil Moisture Characterization With Ground Based Measurements

811

October 2009, Incheon, Korea

elevation increased (figure 3 (d) and figure 4 (d)). While water surface
elevation showed relatively abrupt temporal variations, in-situ soil moisture
had somewhat weak temporal variability patterns with little antecedentpeaks.
25

0.3

25

0.3

Toegyewon Station (2005)
Water Surface Elevation
Basin-averaged Soil Moisture from AMSR-E data

Toegyewon Station (2005 rainy season)
Water Surface Elevation
Basin-averaged Soil Moisture from AMSR-E data

0.15

0.1
22

Water Surface Elevation (EL.m)

23

24
0.2

23

0.15

0.1
22

0.05

21

0.05

0
200

21

300

0
180

200

r
a
e
Y
f
o
y
a
D

100

r
a
e
Y
f
o
y
a
D

0

220

(a)

240

260

(b)
0.8

26
Toegyewon Station (2005)
Water Surface Elevation
In-situ Soil Moisture at Gwangneung

0.8

26
Toegyewon Station (2005 rainy season)
Water Surface Elevation
In-situ Soil Moisture at Gwangneung

0.7

0.7

25

0.4

23

0.3

0.2
22

0.6

0.5

24

0.4

23

0.3

0.2

In-situ Soil Moisture (m3/m3)

0.5

24

In-situ Soil Moisture (m3/m3)

0.6

Water Surface Elevation (EL.m)

25

Water Surface Elevation (EL.m)

AMSR-E Soil Moisture (m3 /m3)

0.2

0.25

AMSR-E Soil Moisture (m3 /m3)

Water Surface Elevation (EL.m)

0.25
24

22
0.1

21

0.1

0
200

300

0
180

200

r
a
e
Y
f
o
y
a
D

100

r
a
e
Y
f
o
y
a
D

0

21
220

240

260

(c)
(d)
Figure 3: Time series of the Water surface elevation and AMSR-E soil
moisture value for (a) 2005, (b) rainy season in 2005and Water surface
elevation and the in-situ soil moisture values for (c) 2005, (d) rainy season
in 2005.
0.3

26

0.3

26

Toegyewon Station (2006)
Water Surface Elevation
Basin-averaged Soil Moisture from AMSR-E data

Toegyewon Station (2006 rainy season)
Water Surface Elevation
Basin-averaged Soil Moisture from AMSR-E data
0.25

0.25

0.15

23
0.1

22

0.2
24

0.15

23
0.1

22
0.05

21

0.05

0
200

21

300

0
200

r
a
e
Y
f
o
y
a
D

100

r
a
e
Y
f
o
y
a
D

0

220

(a)
Toegyewon Station (2006)
Water Surface Elevation
In-situ Soil Moisture at Gwangneung

260

0.8

26
Toegyewon Station (2006 rainy season)
Water Surface Elevation
In-situ Soil Moisture at Gwangneung

0.7

0.7

25

0.4

23

0.3

0.2
22

0.6

0.5

24

0.4

23

0.3

0.2

In-situ Soil Moisture (m3/m3)

0.5

In-situ Soil Moisture (m3/m3)

0.6

24

Water Surface Elevation (EL.m)

25

Water Surface Elevation (EL.m)

240

(b)
0.8

26

22
0.1

21

0
200

(c)

300

0.1

21

0
200

r
a
e
Y
f
o
y
a
D

100

r
a
e
Y
f
o
y
a
D

0

812

AMSR-E Soil Moisture (m3 /m3)

0.2
24

Water Surface Elevation (EL.m)

25

AMSR-E Soil Moisture (m3 /m3)

Water Surface Elevation (EL.m)

25

220

240

260

(d)

New Technologies for Urban Safety of Mega Cities in Asia

Figure 4: Time series of the Water surface elevation and AMSR-E soil
moisture value for (a) 2006, (b) rainy season in 2006and Water surface
elevation and the in-situ soil moisture values for (c) 2006, (d) rainy season
in 2006.
3.2 Regression Analysis
Generally, runoff increases as soil moisture increases in the watershed.
Figure 5 shows the relationship between the ground based soil moisture andthe corrected water surface elevation values. As water surface increases, insitu soil moisture also increases. The relation which assumes the form ofnatural logarithm function between soil moisture and water surface
elevation was identified
26
Toegyewon
2005
2006

Water Surface Elevation (EL.m)

25

24

23

22

21
0

0.1

0.2

0.3

0.4

0.5

0.6

In-situ Soil Moisture at Gwangneung (m3/m3)

0.7

Figure 5: In-situ soil moisture and water surface elevation at the
Toegyewon gauging station of the Wangsuk stream.
h(t )  21.7  0.532 ln

0.55, R 2  0.724
0.55  SM (t )(1)h(t ) : Water surface elevation (m) at time t
SM (t ) : In-situ soil moisture (m3/m3) at time t
A regression analysis approach was used for rainy season. The result ofregression analysis is equation 1 whose coefficient of determination (R2) is0.724.

4. CONCLUSION
In this study, we developed the relationship between in-situ soil moisturedata and water surface elevation time series from the watershed.
Through the regression analysis the data was well fitted to natural
logarithm. It is expected that the correlation between the corrected AMSR-E

Remotely Sensed Soil Moisture Characterization With Ground Based Measurements813

October 2009, Incheon, Korea

soil moisture data associated with in-situ soil moisture data and water
surface elevation time series should be obtained.
Even if AMSR-E’s grid may not provide enough the spatial resolution
for the study watershed, the remotely sensed soil moisture data through the
Cumulative Distribution Function (CDF) matching technique and Regional
Statistics Method (RSM) may be improved to provide a unique relationshipwith water surface elevation at a watershed scale.
ACKNOWLEDGEMENTS
The data were provided by KoFlux from the projects funded by Ministry ofLand, Transport and Maritime Affairs, the Korea Forest Research Institute ,and the Korea Science and Engineering Foundation.
REFERENCES
Hollinger,S.E and Isard, S.A, Soil Moisture Climatology of Illinois,(1994)
Journal of Climate, 7, 822-833
Jackson T.J., Le Vine D.M., Swift C.T., Schmugge T.J., and Schiebe F.R.
1995. Large area mapping of soil moisture using th ESTAR passive
microwave radiometer in Washita ’92. Remote Sens Environ. 53:27-37.
John R. J., 2007. Remote Sensing of the Environment: An Earth Resource
Perspective, Second Edition, Prentice Hall.
Joon K., Dongho L., Jinkyu H., Sinkyu K., Su-Jin K., Sang-Ki M., JongHwan L., Yowhan S., Jaeseok L., Sanghyun K., Namchil W., Kyongha K.,
Buyong L., Byong-Lyol L., and Sung K. 2006. Hydro Korea andCarboKorea: cross-scal studies of ecohydrology and biogeochemistry in aheterogeneous and complex forest catchment of Korea. The EcologicalSociety of Japan. 21: 881-889
Scipal K., Scheffler C., and Wagner W. 2005. Soil moisture-runoff relation
at the catchment scale as observed with coarse resolution microwave
remote sensing. Hydrology and Earth System Sciences, 9, 173-183
Minha C., and Jennifer M. J. 2008. Tempoeal Variability Corrections for
Advanced Microwave Scanning Radiometer E (AMSR-E) Surface Soil
Moisture: Case Study in Little River Region, Georgia, U.S. Sensors. 8,
2617-2627.
Pachepsky Y., Radcliffe D.E., and Selim H.M. 2003. Scaling methods insoil physics. CRC Press. 119 pp.
Rombach, M. and Mauser, W: Multi-annual analysis of ERS surface soil
moisture measurements of differents land uses,1997, 3rd ERS Symposiumon Space at the service of our Environment, Florence, Italy, 14-21 March,
European Space Agency, SP-414, 27-34

814

New Technologies for Urban Safety of Mega Cities in Asia

ESTIMATION OF SEDIMENTS IN URBAN
DRAINAGE AREAS AND RELATIONANALYSIS BETWEEN SEDIMENTS AND
INUNDATION RISK USING GIS
1

Moo-Jung PARK and 2Hwan-Don JUN
Dept of Civil Engineering, Hanseo University, Korea
mjpark@hanseo.ac.kr
2
Dept of Civil Engineering, Seoul National University of Technology,
Korea
hwandonjun@gmail.com
1

ABSTRACT
Sediments entering the sewer in urban areas reduce the conveyance insewer pipes, which increases inundation risk. To estimate sediment yields,
individual landuse areas in each sub-basin should be obtained. However,
because of the complex nature of an urban area, this is almost impossible toobtain manually. Thus, a methodology to obtain individual landuse areasfor each sub-basin has been suggested for estimating sediment yields. Using
GIS, an urban area is divided into sub-basins with respect to the sewerlayout, with the area of individual landuse estimated for each sub-basin.
The sediment yield per unit area for each sub-basin is then calculated. The
suggested method was applied to the GunJa basin in Seoul. For a relation
analysis between sediments and inundation risk, sub-basins were ordered by
the sediment yields per unit area and compared with historical inundation
areas. From this analysis, sub-basins with higher order were found to matchthe historical inundation areas.
1. INTRODUCTION
Recently, rapid changes in the weather, such as flash floods in urban areas,
frequently occur due to climate abnormalities over the world. For mosturban watersheds, which have a large portion of impervious areas and shorttravel times, as a result of urbanization, the risk of inundation increases withthe occurrence of flash floods or storms. Sewer systems, which play animportant role in discharging storm flow to receiving waters, haveexperienced decreases in their conveyance due to the accumulation of
sediments or solids in the sewer pipes. According to the USEPA report(EPA, 2004), the decreased conveyance increases the risk of inundation.
However, insufficient attention has been paid to research on evaluating theeffects of sediments or solids accumulation in sewer pipes on the increased
risk of inundation. Thus, it is important to develop a methodology forevaluating the effect of reducing the risk of inundation in urban areas.
Most previous research associated with sediment yields from the overland
surface has been made with regard to environmental characteristics.

815

October 2009, Incheon, Korea

However, various sediment sources, as well as the characteristics of
sediments or solids, which occur from urban overland surfaces make thedevelopment of an efficient methodology for quantifying sediment yields
and the evaluation of their effects difficult. One of the earliest examples ofresearch on the subject, by Dalrymple et al. (1975), analyzed the distributionof the solid grain size (or accumulated sediments) collected from the insideof separate or combined sewer pipes with respect to the settlement
characteristics. Klemetson et al. (1980) and Ashley et al. (2004) studied thecharacteristics of solids in combined sewer pipes and a method for theirremoval. However, their study only dealt with solids in sewer pipes, but nottheir various sources from overland surfaces. Brinkmann and Graham(2001) suggested a method for the removal of sediments from urban
drainage areas, and Toy et al (2002) studied a mechanism and suggested amethodology for predicting soil loss. However, these studies were notsuitable for application to soil loss in urban areas. Lee and Park (2006)
reported their results of estimating sediment yields from urban overland
surfaces and for the sediment loads inside the sewer pipes. In their method;
however, they simplified the land use areas in each sub-basin to obtainparameters for the equations used to estimate the sediment yield; therefore,
the accuracy of their model may not be high. Thus; in this study, a method
for accurately and efficiently estimating sediment yields from various
sources has been suggested and a relation analysis performed between
sediment yields and the risk of inundation. For application of the method, a
GIS is used to obtain the area of individual land use in each sub-basin, as
well as data for urban drainage areas, which have complicated structures.
An individual land use was categorized and built into the GIS data on thebasis of the research of Lee et al. (2005) and Min and Kim (2006). Using theland use data and GIS, the suggested method was then applied to a realwatershed in Seoul, Korea. As a result, it is possible to accurately estimate
the amount of sediments compared to the field data and identify thepotential inundation risk areas.

2. METHOD TO ESTIMATE SEDIMENT YIELDS IN URBAN
DRAINAGE AREAS
The model suggested by the USEPA (EPA, 2004) was used to estimate thesediment yields from urban drainage areas, which is a grey-box model and;depending on the sediment sources, the sediment yields from each source
can be estimated. The sources were divided into four categories, namely:
Litter/Floatables, roadway sanding for snow/ice events, street dust and dirt,
and soil erosion. The sediment yields were calculated for each source using
relatively simple equations. The annual Litter/Floatables volume can becalculated using the equation suggested by Armitage and Rooseboom(2000), which was developed as an empirical equation relating to South
Africa. An estimate of the roadway sanding used for snow/ice events was
obtained using Guo’s equation (Guo, 1999). However, only a portion of thesand estimated by Guo’s equation can be consider a nonpoint source, assand can be collected by road-cleaning vehicles or cleaning laborers after

816

New Technologies for Urban Safety of Mega Cities in Asiasnow-melt. According to Guo (1999), about 30% of the total sand sprayedroad surfaces are transported by storm runoff and collected in retention or
detention basins. However, this will vary according to the condition andmaintenance practice of a given watershed. To estimate the accumulation
loading of dust and dirt, Hurber and Dickinson (1998) used three equations.
Of these equations, the Michaelis-Menton equation was used in this study.
The amount of soil erosion was estimated using the Revised Universal Soil
Loss Equation (RUSLE). The details of each equation and their range ofparameters are presented in the USEPA report (EPA, 2004)

3. APPLICATION OF GIS TO URBAN DRAINAGE AREAS
3.1 Classification of landuse
To estimate the sediment yields from urban drainage surfaces, it isnecessary to divide the land use of urban areas into several classes, namely:
high-density and low-density residential areas, schools, commercial areas,industrial areas, parks and roads, as the sources and sediment yields are
determined by individual land use. Moreover, in the case of roads, one
needs to measure road lengths to estimate the amount of dust/dirt, which canbe facilitated using GIS.
3.2 Delineation of subbasins
In water resource engineering, most GIS applications are used foranalyzing natural watersheds, especially their delineation. However, sinceurban drainage areas have a different structure from natural watersheds, i.e.,
stormflow runs through a man-made sewer system, sub-basins should bedelineated along with the sewer pipeline. In addition, elevation of urban
surfaces is another factor that has to be defined.
3.3 Data acquisition and Geoprocessing
To classify an individual land use, the CAD drawings established by
the Sewer Division of Seoul Metropolitan Government were employed. In
these drawings, individual land uses are stored in different “Layers”, so thateach layer can be separately converted into a “shape file” format of ESRI.
For the delineation of sub-basins, drawings of the sewer layout and theelevation data were used, the detail process of which is shown in Figure 1.
Individual land use areas within each sub-basin were estimated by applying
GeoProcessing functions, including “Intersect” and “Erase”.

Estimation of Sediments in Urban Drainage Areas and Relation Analysis between Sediments and Inundation
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817

October 2009, Incheon, Korea

Figure 1: The process of data acquisition
These areas are the parameters used in the four equations to estimate
the sediment yields. Estimating the “alley” areas for each sub-basin requires
additional steps; whereas, the other land use areas for each sub-basin can beeasily estimated, as is shown in Figure 2.

Figure 2: The process to obtain an “Alley”

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New Technologies for Urban Safety of Mega Cities in Asia

4. REAL URBAN DRAINAGE AREA FOR APPLICATION OF THE
SUGGESTED METHOD
4.1 The target area and individual landuse shape files
The urban drainage area, Gun Ja basin, where the suggested method
was applied, is located in Seoul and has had some inundation events during
the past decade. Its area of the GunJa basin is 193.62ha and divided into 26
subbasins. Of these, sub-basin “0” is part of the JoongRang stream, where
no sediment is produced; therefore, it was not considered when estimating
the sediment yields. The overall shapes of the area and files when converted
from the CAD drawings from the application of the geoprocessing areshown in Figure 3.

GunJa area

GunJa area

High-density residential

Commercial

Main roadIndustrial

School

Park

Alley

Figure 3: The shape files for individual land uses converted from CAD
drawings
4.2 Determination of the parameters
To apply the four equations mentioned earlier, certain parameters haveto be determined. Since the determination of these parameters is very
difficult, requiring vast field surveys, which are a time- and cost-consuming
task, the parameters were reasonably determined using the parameterssuggested in the respective researches for the estimation of litter/floatables,
roadway sanding for snow/ice events, and street dust and dirt. In the case of

Estimation of Sediments in Urban Drainage Areas and Relation Analysis between Sediments and Inundation
Risk Using GIS
819

October 2009, Incheon, Korea

soil loss, the parameters used in a disaster analysis for a project to build anurban park in Seoul were substituted (Seoul Metropolitan Government,
2003). The determined parameters are shown in Table 1.
Table 1: Parameters for individual land use
Low-Density High-Density
Commercial Industrial School
Residential Residential

Land use

Sanding

1

1

1

1

1

1

Vi
(m3/ha/yr)

0.02

0.02

0.03

0.03

0.03

0.01

N/A

N/A

Bi
(m3/ha/yr)

0.01

0.02

1.2

0.8

0.02

0.5

N/A

N/A

ws(kg/m2)

N/A

N/A

N/A

N/A

N/A

N/A

10

5

N/A

N/A

N/A

N/A

N/A

N/A

250

250

N/A

N/A

N/A

N/A

N/A

N/A

0.9

0.9

N/A

N/A

N/A

N/A

N/A

N/A

10

10

R
(107/ha․ mm/hr)

526

526

526

526

526

526

N/A

N/A

K
(tonnes/ha/R)

0.13

0.13

0.13

0.13

0.13

0.13

N/A

N/A

0.231

0.231

0.231

0.231

0.231

0.231

N/A

N/A

0.1

0.1

0.1

0.1

0.1

0.1

N/A

N/A

0.14

0.14

0.14

0.14

0.14

0.14

N/A

N/A

DDFACT(day)
T(day)

USLE

Alley

1

DDLIM((g)
Dust/Dirt

Main Road

1

fsci
Litter/Floatables

Park

LS
C
P

It should be noted that the amount of sediment from the urban drainage
surface calculated using the stated equations, with the suggested parameters
shown in Table 1, will be greater than the amount of sediment entering
sewer pipes. In the case of litter/floatables, one of the parameters in theequation was the retrieving rate represented by a street cleaning factor foreach land use ( f sci ). However, for roadway sanding and dust/dirt, there is no
retrieving rate in the equations. This means that all the solids calculatedusing the suggested equations will be considered as sediments entering
sewer pipes. As mentioned earlier, for roadway sanding, Guo (Guo, 1999)
reported that only 30% of sand sprayed road surfaces would enter the sewer
pipes in the case of urban drainage areas. However, this may vary according
to the condition of the urban drainage surface and maintenance practice, i.e.
how many times cleaning vehicles are operated and the amount of snow.
Therefore, a field survey is required to determine how much sand isretrieved by cleaning vehicles or other methods. In the case of the target
area located in Seoul, the retrieving rate of roadway sand was less than 5%(Kim et al., 2004); therefore, the retrieving rates of roadway sanding and thewash-off of dust/dirt were assumed to be 0% and 0 g/curb-meter. To verify
this assumption, the field survey data will be presented later.

4.3 Results of sediment yield estimation

820

New Technologies for Urban Safety of Mega Cities in Asia

Using the suggested method, the sediment yields from four sourceswere estimated, as shown in Table 2.
Table 2 : Results of estimated sediment yields by sub-basin
Sub-basin
Litter/(ID)
Floatables(kg)

Sand
(kg)

DD
(kg)

USLE
(kg)

Area
(m2)

Sediment yield S.Y. per unit Order of S.Y.
(kg)
area(kg/yr/m2) per unit area

1

57.87

13,772.10

178.67221.1429,927.21

14,229.78

0.48

13

2

77.12

63,810.50

186.3865.00

25,165.75

64,139.01

2.55

3

3

57.59

0.00

170.4556.93

18,582.61

284.97

0.02

24

4

392.5758,993.10

290.301638.22

151,969.89

61,314.19

0.40

14

5

141.210.00

359.66467.8262,903.62

968.70

0.02

23

6

472.42

110,500.10

924.60578.41

124,918.75

112,475.54

0.90

11

7

175.8890,557.10

230.41

195.0942,119.43

91,158.48

2.16

4

8

0.00

51,724.80

17.98

0.00

5,172.48

51,742.78

10.00

1

9

259.5974,698.30

310.78330.9256,580.07

75,599.59

1.34

10

10

271.89118,874.30

390.32285.4660,858.94

119,821.97

1.97

6

11

181.81

57,683.00

199.40

196.0036,578.89

58,260.21

1.59

8

12

140.6084,571.90

263.87202.9841,534.09

85,179.34

2.05

5

13

669.98201,412.10

782.99944.37

151,810.93

203,809.44

1.34

9

14

0.74

256,298.60

88.08

0.52

25,670.12

256,387.94

9.99

2

15

246.990.00

198.92812.1464,921.36

1,258.05

0.02

20

16

116.290.00

392.92455.8563,431.44

965.06

0.02

25

17

457.820.00

258.911258.96

95,104.31

1,975.69

0.02

19

18

33.95

0.00

53.17

67.88

9,797.48

155.00

0.02

22

19

3,813.44

206,563.20

347.018935.07545,278.35

219,658.71

0.40

15

20

124.350.00

264.80347.7742,225.10

736.91

0.02

21

21

385.49228.00217.89412.8752,082.64

1,244.26

0.02

18

22

238.40137,716.80

481.77437.6577,640.44

138,874.62

1.79

7

23

430.6062,111.70

371.88554.3877,044.94

63,468.56

0.82

12

24

98.04

14,112.80

206.36297.4548,833.61

14,714.66

0.30

16

25

199.050.00

285.76177.9229,814.31

662.72

0.02

17

Total

9,061.17

1,603,683.20

7,473.30

18,975.82

1,939,966.76

1,639,193.49--

The total sediment yield was 1,639 ton/year, and that of roadway
sanding was 1,603 ton/year, which were the dominant sediment sources,
accounting for about 97% of the total sediment yields, which implies thatfor urban drainage areas, roadway sanding during the snow season is critical
for reducing sediment yields. This result was compared with the dataobtained from a field survey. The field survey was based on the dredging
and road cleaning records of the local governments of Gwang Jin-gu andSeoung Dong-gu, Seoul, which are maintained for a three year period. The
annual averages of each item were calculated, and are shown in Table 3.

Estimation of Sediments in Urban Drainage Areas and Relation Analysis between Sediments and Inundation
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821

October 2009, Incheon, Korea

Table 3 : Comparison between the estimated and surveyed sediment yields
Item

Annual average (kg)Remarks

Roadway cleaning

70,230

By cleaning vehicles and labors

Dredging (sewer pipes)

1,290,600

Wet specific weight 1,800kg/m3

Dredging (retention basins)

67,140

Wet specific weight 1,800kg/m3

Total

1,427,970-

Total sediment yields estimated1,639,193

13.0% greater than the field survey

From a comparison, the estimated data were found to be 13% greater thanthose from the field survey. Taking into account the uncertainty in thedetermination of the parameters and assumptions, the sediment yields
estimated can be considered reasonable estimations, with the suggested
method using GIS adjudged to be applicable. However, further applicationsof the suggested method will be required to verify its applicability.
4.4 Inundation risk analysis
The sediment yields per sub-basin were estimated, and order the sub-basinsaccording to the sediment yield per unit area. This was used to verify the relationshipbetween the amount of sediments and the risk of inundation. Basically, sub-basins
with a high ranking order according to the sediment yield per unit area were assumed
to be vulnerable to inundation, as the conveyance of the sewer pipes may be reducedby the accumulation of sediments or solids. In the basin, the highest and second
highest sub-basins were “8” and “14”, respectively, but contained main roads; thus,
sub-basin “2” was the highest that contained sewer pipes. For this reason, sub-basins“2”, “3”, “4”, “5” and “6” were selected as expected inundation regions. The
inundation records for 1998 were collected, and are displayed for those sub-basins.
As shown in Figure 4, the expected and historical inundation regions matched. The
same region had another inundation event in 2001. Interestingly, over the last decade,heavy snow events were recorded during 1998, 2001 and 2004. Two inundation
events occurred during the rainy seasons in 1998 and 2001. Thus, a high risk ofinundation may result from much sediment due to roadway sanding. Of course, it isobvious that many factors contribute to increase the risk of inundation, but according
to our analysis, sediment yields also contributed to the increased risk of inundation.

Expected inundation risk areas (subbasin 2,3,4,5, and 6)

822

New Technologies for Urban Safety of Mega Cities in Asia

Comparison between historical inundation area (Filled in blue)

Figure 4: The expected and historical inundation risk areas

5. CONCLUSIONS
Due to the mixture of individual land uses in urban drainage areas, it is very
difficult to estimate individual land use areas within each sub-basin, which
is one of the basic parameters for estimating sediment yields, but using GIS,
these can be easily and accurately estimated. To anticipate high inundation
risk regions, the results of the sediment yield estimation were employed, andmany sediment yields were found to increase the risk of inundation. It is
obvious that further applications and comparisons will be required toconfirm this conclusion, but the suggested method will be useful when
performing additional research.

6. ACKNOWLEDGEMENTS
This study was supported by the 2003 Core Construction Technology
Development Project (03-SANHAKYOUN-C01-01) through the Urban
Flood Disaster Management Research Center in KICTTEP of MOCT Korea.

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