I C U SNewsletter
Volume 15

Number2

July to Sept. 2015

International Center for Urban Safety Engineering
Institute of Industrial Science, The University of Tokyo

Potentiality of Road Blocking
to Improve Evacuation Environment from Tsunamii
By Y. Honma
Lecturer, ICUS, IIS, The University of TokyoINTRODUCTION
By the Great East Japan Earthquakeof March 11, 2011, a tsunami withunimaginable proportions was
induced and it assailed the region,
killing many lives. In its aftermath,tsunami evacuation procedurescame under review. The Japanese
Government had set evacuation on
foot as the basic rule for tsunami
evacuation. However, when atsunami warning was issued in
Ishinomaki City, Miyagi Prefecture,
following the strong earthquakeat the end of 2012, many people
attempted to evacuate to a higher
ground by cars, causing major traffic
congestion. Such situations may
occur in the event of similar future
events, so alternative measures
should be instituted expediently.
While there have been manystudiesofevacuationfromtsunamis, few studies have appliedmathematical analysis and few haveanalyzed traffic congestion during
an evacuation. Although there areroad regulations aimed at securing
passage for emergency vehicles or
prohibiting entry to areas forecast
for inundation, few regulations
have been put in place concerning
evacuation times.

detours during emergency periods,
leading to a reduction in traffic
congestion and evacuation time. The
study is aimed at minimizing thetotal time taken for evacuation byproposing appropriate road closure
strategies for a range of evacuation
options.

This study attempts to reduce
preferential car use in major
earthquake disasters by setting roadrestrictions. Initially, restrictions aredefined as road closures. The goal isto reduce the number of car users and

DESCRIPTION OF THE STUDYThis study analyzes the possible
reduction of the total time required toevacuate by closing key roads (links)
in the network. We take Shizuoka

Sizuoka City

Figure 1: Details of the road network in the subject area

City as our example, where tsunami
disaster by a Nankai megathrustearthquake is anticipated.
When a major earthquake strikes,
evacuees will start to evacuate froma point in the red-lined area (start ofevacuation node) using roads (links)
to evacuate to a point in the blacklined area (high ground node). At thesame time, some of the roads will
be closed to automobile traffic andevacuees are expected to recognize
road closures in advance.
It is assumed that people will
choose the shortest evacuation routeand evacuation time by car and by
foot. This was modeled using a logit
model, which is a method to predict
the selection behavior of a means oftransportation.
If there were no road closures, alarge percentage of people would
choose car, as that would allow themto evacuate more quickly while
fewer people would choose to walk.
Although evacuation speed on footis slower than that by car, becauseof the absence of congestion,
evacuation can be completed ina predictable amount of time. In
contrast, evacuation by car can becompleted quickly on roads wherecongestion does not occur, but majorroads, such as highways and roads indensely populated areas, will become
extremely congested, leading towide variation in the amount of time
taken for evacuation. The averagetime required for evacuation by car
will actually become longer.
For this reason, road closures
are introduced. These change theroutes available for car evacuation,
producing a (perceived) increase in
the time required. Under the roadclosure scenario, some evacuees who

Page 2(a) Where road closures are not enacted(b) Where road closures are enacted
Figure 2: Easing congestion by enacting road closureswould have previously used a car
will evacuate on foot or will take adetour, avoiding the concentration of
traffic on certain roads. This avoids
major congestion, reducing the
average time required for evacuation(Figure 2).
In this study, we assumed a walking
speed of 2.75 km/h, based on therecommendations in the Tsunami
Affected Urban Area Restoration
Method Survey issued by the
Ministry of Land, Infrastructure,
Transport and Tourism. Cars weremodeled with route selections thatwould not take congestion into
account and assigned movement
speeds for each link using the Bureauof Public Roads (BPR) function.
Ultimately, we can calculate
several road closure combinations
which optimize various factors. It
should be closely discussed what
factor should be optimized. For
example, maximum evacuation timeis one of the factors when we focus

ICUS Newsletter Vol. 15, No.2

on the worst person. In this study,
we weighted all of people equally,
and minimize the average evacuation
time. It is compared to the situation
with no road closures.
The combination of roads forclosure exists as 2 to the power ofthe number of links, so searching
through all of them is not realistic.
Therefore, this study expressed thedecision whether to close a roador not as 0 or 1, where 0 is no roadclosure, and used a meta-heuristic
genetic algorithm to derive thesolution.
The existing literature gives
recommendations for each region bysolving the shortest route problem,
where single evacuation methods
are discussed, but few studies havesimultaneously considered multiple
modes of evacuation by driving or
walking.
Ingeneral,solutionsof
optimization problems tend todeteriorate
whenrestrictions
are applied. The significance of
this study is that we have added
restrictions in the form of roadclosures, yet have derived improved
solutions. This is possible because
the excessive traffic generated by

the BPR function was resolved by
implementing road closures.
CALCULATION RESULTS
In this study, the average timerequired for evacuation in Shizuoka

Figure 3: Network showing road closure locations

City improved from 9.41 min prior
to applying road closures to 6.62
min after application. The roadclosure sites used in this scenario
are shown in Figure 3. In this figure,the gray-lined areas in the network
are nodes requiring evacuation, theareas in black are the destination
nodes, and the bold blue lines are thelinks that are subject to road closure.
Generally, people are supposedto evaluate in a north-westward
and north-eastward directions, so
it is effective to enclose the roads
toward such directions. Actually,
we can confirm that relatively longnorthwestward roads are closed.
The distribution graphs ofevacuation times from each node totheir evacuation sites are shown in
Figures 4 and 5. These figures show
comparisons of car traffic before andafter road closure, respectively. It
can be seen that there are roads with
reduced traffic volumes and thatvehicles have taken detours.
FUTURE PLANS

Figure 4: Time distribution in generation 0 (no road closures)

These trial calculation results stillleave some issues unresolved. In thisstudy, the number of vehicles in eachlink was calculated as the cumulative
total when deriving the numberof cars passing through a link andcalculating the average time required
for evacuation. However, in reality,
the flow of car traffic is dynamic;
hence, by extending the model toevaluate dynamical flows, we areable to calculate more accurate
evacuation time. This extension alsoenables us to derive the number ofpeople who are captured by tsunami
by overlapping tsunami rushing anddynamical traffic flows, which is themost important evaluation factor insuch analyses.

Figure 5: Time distribution in generation 100 (optimal solution)

ICUS Newsletter July. to Sept. 2015

Page 3

7th Joint Student Seminar on Civil Infrastructure:
Bangkok, Thailand
By Y.Honma

The 7th Joint Student Seminaron Civil Infrastructure washeld on August 19th, 2015 at
Sasa International House of
Chulalongkorn University, Thailand.
The seminar was composed ofinvited professor section and student
presentations. Three professors
made invited lectures about leading
topics of civil engineering, andfourteen students from universitiesin Thailand, Japan, and Korea gave
presentations on their researches
in different fields. Three students
from the University of Tokyo wereawarded “Excellent Presenters”.
Owing to the tragic bomb accidents

which was happened at the sametime in Bangkok, planed fieldtrip
tour was cancelled for safety
reason. Through the seminar, allof seminar participants shared not
only research perspectives, butalso, most importantly, a platform
to develop a network of friendshipthat is invaluable as an informal
platform to exchange ideas andinformation in the future.

Photo of seminar participants

SATREPS: 1st JCC and Kick-off Meetings
By A.Kodaka

On September 18th 2015, the 1st
Joint Coordination Committee (JCC)
meeting was held at Grand Amara
Hotel in Nay Pyi Taw, Myanmar.
JCC is the highest decision making
body of the project and it approves

Signing of M/M (From left: Prof. Kimiro
Meguro, H.E. U Ko Ko Oo, and Prof. Aye
Myint)an annual work plan, reviews
overall progress, and exchanges
opinions on major issues that may
arise during the implementationof the project. A Kick-off meeting
was also held at the opening of JCC
meeting to celebrate the launchof the project. The meeting was
opened with addresses from H.E.
U Ko Ko Oo, Union Minister of
Science and Technology (MOST),Prof. Aye Myint, Rector of Yangon
Technological University, and Prof.
Kimiro Meguro, Director of ICUS.
Subsequently, JCC meeting chairedby H.E. U Ko Ko Oo was opened

and following topics were discussed
and agreed: Revised Project Design
Matrix and Plan of Operation, six
research groups progress reports
and future activity plans, necessarydata, and project members. The
meetings
were
successfully
closed with signing of Minutesof Meetings (M/M). A total of 41
people participated in JCC meetingfrom major counterpart ministries
and organizations including MOST,
Ministries
ofTransportation,
Agriculture
andIrrigation,
Construction, and Yangon City
Development Committee.

Student research: Seismic Retrofitting of Unreinforced
Masonry Houses with Abaca Fiber Reinforced Mortar andAbaca Rope Mesh
By: Suhelmidawati Etri

In the last hundreds years, there
were many earthquakes haveoccurred in around the world,Page 4including developing countries,
which caused a big amount of
fatalities. Mainly, these fatalities are

ICUS Newsletter Vol. 15, No.2

due to the collapse of unreinforced
masonry (URM) buildings, whichwere very common in developingcountries. Most URM buildings arebuilt with little or no considerationof seismic loading, and these
are not capable of resisting the
expected seismic ground motion.
Regarding these facts, retrofittingof URM buildings is the key issue
for earthquake disaster reduction,
especially for reducing humancasualty. For this reason, there aremany kinds of retrofitting materials
and methods have been developed
and used to strengthen URM
houses, such as Fiber Reinforced
Polymers (FRP), steel mesh cage,
surface treatment, etc. They cancontribute somehow to increase
strength and modulus for structural
applications. However, they are
relatively expensive and notavailable in many parts of the world,which is of prime importance in thethird world countries. Therefore,
we propose to use a natural fiber

called Abaca fiber as reinforcementin cement lime mortar, Abaca Fiber
Reinforced Mortar (FRM) and
Abaca fiver rope in mesh style,
Abaca Rope Mesh (ARM). Abaca isa locally available and inexpensive
material with high tensile strength.
In order to investigate theeffectiveness of these methods, theexperimental tests were conductedconsists of the axial tensile tests,

Shake table test

in-plane tests, out-of-plane tests,
and shake table tests. Based on the
results obtained by the above tests,
it can be concluded that FRM andARM methods have high potential
for retrofitting URM houses indeveloping countries by showing
the larger deformation capacities
and bigger energy dissipation
capacities.

The 3rd International Conference on Urban Disaster
Reduction held in US, 2015

Development of Simplified Numerical Modelfor Seismic Collapse of RC Frame Structures
By Rajasekharan Shanthanu Menon

Collapse of buildings due toan earthquake is completely
unacceptable. The combinationof wide usage of Reinforced
Concrete (RC) framed structures forresidential buildings in earthquake
prone areas and shoddy design andconstruction practices, exposes
the high vulnerability of this typeof buildings to a seismic hazard.
Assessing the collapse capacity ofsuch buildings in advance is very
important for disaster reduction.

There are various methods to assess
the collapse capacity of buildings
but there always seems to be astand-off between the applicability/
reliability of these methods andthe computation effort involved.
Moreover, for better reliability, alarge number of simulations have tobe performed to compensate for the
epistemic/aleatoric
uncertainties,
further increasing the computation
effortrequired,sometimes,
rendering most numerical methods

State
low
NormalLinearSeismic Loading

Non-linear
DamagedState

Collapsed
State

Implicit

Only pore
springs

PHASE IIEXTENDED
DISTINCTELEMENTMETHOD

Explicit

Pore + contact
springs

Cracking
Separation

high

PHASE I
MAPPEDSPRINGNETWORKCollapse

impractical.
Considering the above problem,
an effective two-phase numericalcollapse simulation of structures
can be performed, which canpredict the initial behavior of RC
structures (elastic/nonlinear/crack
initiation/ stiffness degradation/
maximum load capacity) through afinite element mapped nonlinear RC
spring network (implicit numericalintegration) and predict the final
behavior of structures (geometric
non-linearity, instability, separation,and collision) through the Extended
Distinct Element Method (explicit
numerical integration). By using
the proposed scheme, large
number of simulations can be
performed in moderate computing
environments, which is useful forpractical vulnerability assessment ofbuildings, especially in developing
countries.

ICUS Newsletter July. to Sept. 2015

Page 5

SATREPS activity report: Infrasfrucfure(management) group
By K. Matsumoto

The infrastruture (management)group of SATREPS conducted thesite investigation on deteriorationsof road bridges in Myanmar from
7th to 11th September, 2015. The
investigators were Prof. Yokota,
Dr. Nagai, Dr. Miyashita, Dr.
Henry and the author. Figure 1
shows the target bridges. Bridges
in Yangon City and Rakhine State
were investigated.
Photo 1 shows Thakhut bridge,
which is a simply-supported RC
girder bridge located in southern
region of Yangon City. As shown in
Photo 1(a), the girder moved fromthe center of piers and falling of thegirder is concerned. It is consideredthat the movement of the girder iscaused by soft ground conditionin Yangon region and insufficientstrength of the foundation. Photo1(b) shows the bottom side of theslab of Thakhut bridge. Severe
damage due to corrosion ofreinforcing bars can be seen, whilealmost no damage was observedin the neighbor girders. One ofthe possible causes of the damage
to these slabs is inner chlorides
induced by improper materials
such as sea water.
Photo 2 shows bottom side of RC
slabs of the bridge, which is locatedin the national road in RakhineState near the Ramree Island.

Even though only around 10 years
have passed after the construction,
significant steel corrosion occurs inthe briges in this region. The personof MOC (Ministry of Construction,
Myanmar) explained that thesevere corrosion occurred due tothe use of sea water and sea sand in
the concrete.
As a conclusion of this site
investigation, it is noticed thatmovement of substructures due tosoft ground condition in Yangon
region and initial defects due tolow construction quality are oneof the primary factors of the recent
deterioration problem of bridges in
Myanmar.

In Ramree Island

In Yangon

Figure 1: Target bridges of the site investigation(a) The girder moved from the pier(b) Significant damage to the slab vs. less damage in girder

Photo 1: Damage to Thakhut bridge (Yangon)

Page 6

ICUS Newsletter Vol. 15, No.2

Photo 2: D
 amaged RC slabs of thebridge (Rakhine)

SATREPS Activity report: Water-related disaster group
By A. Kodaka and A. Kawasaki

From August 17 to 24, 2015,
Water-related
disastergroup
conducted a workshop and a joint
field survey with stakeholders in
Myanmar. The workshop led by
Keio University’s team was held at
Yangon Technological University(YTU) on 18th and 19th August
2015 with the title of “Stakeholders
workshop for designing water–
relateddisastermanagement
system”. The purpose of theworkshop was to elicit requirementsof stakeholders for water resource
management system in Myanmar.
A total of 32 people participatedin the workshop from various
governmental agencies: Irrigation
Department (ID), Ministry ofAgriculture and Irrigation (MAI),
Department of Meteorology andHydrology(DMH),
MinistryofTransportation(MOT),

Directorate of Water Resources
and Improvement of River System(DWIR), MOT, and Relief andResettlement Department (RRD),
Ministry of Social Welfare, Relief
and Resettlement (MSWRR). The
workshop was successfully closedwith active discussion on issues andsolutions for sustainable use of thesystem. Subsequently, we conducted
the field survey to Bago River basinwith Myanmar project members
including YTU, ID, and DMH, tounderstand a situation of flooding,response and flood relief operation
by government agencies. Firstly, weinvestigated operations of waterrelated infrastructures managed by
IDI such as weir, sluice/lock gate,
and cannels. We also visited hydrometrological observation stationsof ID and DMH to understand theirsituation of data acquisition anddata sharing among government
agencies. Secondly, we visited
Bago offices of RRD, and General
Administration Department (GAO)
to investigate flood relief operationof Myanmar government. We also
could investigate storage of flood
aid which was located in a temple.
Lastly, we visited flood prone
areas to investigate flood response
behavior of local residents includinginterview survey to temples thattake important roles on evacuation.
In total of 11 people attended thefield survey. The results of theworkshop and the field survey will
be summarized as one of the outputsof the project. For more information
about the flooding, please refer
the official situation reports
published by National Natural
Disaster Management Committee(NNDMC).

Bago office of RRD

A sluice gate managed by ID

Interview to a monk

SATREPS activity report: Earthquake-related
disaster group
By H. Gokon

Building team of Earthquakerelated disaster group in the
SATREPS project visited Yangon
City from September 15 to 25,2015 to have a discussion with thecounterparts in Yangon Technological
University (YTU) and Yangon City
Development Committee (YCDC)
on future plan, and to conduct
field surveys for understanding thefundamental vibration characteristics
of buildings in Yangon City andground condition. From Japaneseside, researchers from the University

of
Tokyo
and
Tohoku University
participated in thetrip.
As one of our
missions is to assessthevulnerabilityof buildings inYangon City tonatural disasters,
we investigated thetypes of building
structures and theirfeatures. Photo inDistribution of sites visited by the building team

ICUS Newsletter July. to Sept. 2015

Page 7

the right shows the sites visited bythis team members. We took photosof building facade by GPS camera,
and all the data were displayed on
Google earth. We could find thatmain structures in the urban area,
not only in the downtown but also
in the residential area, were madeof reinforced concrete (RC) withbrick wall. We could also have an
opportunity to enter the a centuryold RC buildings, and survey thecurrent condition from the inside of
the structure.
As a preliminary survey toinvestigate the ground condition
and the building characteristics inthe future, we tried microtremor
measurements at somelocations in Yangon
City. We could learn
severaltypes
ofproblems for deploying
the survey in the whole
Yangon City, and once
again,
understoodthe importance ofMembers joined site survey in September, 2015
the corporation with

Editor’s note…
SATREPS project has been
actively carried out by ICUS
members and partners. During thetime of this volume, each researchgroup performed field survey. To
visit the sites and have discussion
among members, counterpart andlocal engineers are very important tounderstand the real situation correctly
and share the image of the projecttarget. I am a member of infrastructuregroup and visited Rakhine region, west
part of Myanmar, where the severely
damaged bridges exist due to the useof salt water from sea in concrete
causing the corrosion of steel. Why
did it happen despite it should not be
used? Local engineer explained theRound table discussion among members

counterparts.
In the discussion with YTU andYCDC, we mainly discussed thedata needed for the vulnerability
assessment and how to map theinformation. That was the firstmeeting for some members, andwas good opportunity to know eachother, especially background of themembers (see above photo).

difficulty of getting fresh water there
because that region faces sea andlowland so that even the river watercontains salt. To proceed the project,
it becomes important to consider thereal local situation like this issue.
Establishment of good partnership andcommunication will be a key to makethe project successful.
by K.MatsumotoInternational Center for Urban Safety Engineering (ICUS)
Institute of Industrial Science, The University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
Tel: (+81-3) 5452-6472, Fax: (+81-3) 5452-6476
http://icus.iis.u-tokyo.ac.jp

The International Center for Urban Safety Engineering (ICUS) is a research
center located at the Institute of Industrial Science, The University of Tokyo.
The purpose of ICUS is to identify, investigate, and resolve issues towards therealization of sustainable urban systems for the prosperity and safety of society
considering challenging socio-economic problems.