国総研ニューズレター
NILIM News Letter

No.49

Summer 2014

■ A Public Experiment on Debris Flow: Approaching Mechanism of the Driftwood Disaster Occurrence
Sabo Department, Sabo Planning Division

A public experiment has been conducted to clarify the impact
on the range of driftwood inundation by the particle sizeof sediment in a debris flow in the case of the inundation bydriftwood accompanying a debris flow on June 9, 2014.

case including a large quantity of fine particle size sediment, thedriftwood was carried further in the direction of the debris flow,
but in the experiment case not including a lot of fine particle size
sediment, the driftwood spread out laterally. This experimenthas revealed that differences between sediment can impact theinundation of a debris flow containing driftwood. The Sabo
Planning Division will analyze these results at the same time as
it carries out surveys of actual conditions and a study based on
numerical calculations etc. to improve debris flow and driftwoodinundation prediction technologies.

Disasters occurred in Izu-Oshima in October of last year andin Aso in 2012, including frequent severe sediment disasters.
The Sabo Planning Division has conducted surveys and researchon debris flow and driftwood flow and inundation phenomena
and methods of countering these phenomena. Among these,experiments using channels, models, etc. are useful methods ofDetails * Sabo Planning Division web site
clarifying debris flow mechanisms. In June, that is also sediment
http://www.nilim.go.jp/lab/rbg/index.htm
disaster prevention month, part of the experiments were carried out
publicly for members of the press. The experiment
was done by mixing sediment and driftwood ina debris flow to confirm the way the debris flow
flowed and inundated the land (Photo 1).
The experiment was done in the presence ofmany members of the media during rainfall on theafternoon of June 9 (Photo 2). On the day of thepublic experiment, two different experiments using
sediment with different particle sizes including
Photo 1: Experiment channel
Photo 2: View of the public experimentdriftwood were conducted. In the experiment■ Social experiment of road safety measures for school commuting routes
Road Traffic Department, Road Division

To implement traffic safety measures for school routes, fromOctober to December 2013, a social experiment was conductedwith the cooperation of Tsukuba City and Tsukuba Central
Police, confirming the effectiveness of countermeasures.
In recent years, traffic accidents involving children walking toand from school have been reported one after another, increasing
the publicʼs desire that safety on school routes be ensured. TheNILIM has, guided by its commitment to traffic safety withpriority on people, researched measures to protect the safety ofpedestrians and cyclists on school routes and on other community
streets.
The social experiment was done in sections where it is difficult
to install sidewalks because the road is too narrow, sections which
are somewhat wide, but many vehicles travel through at highspeed, and streets used by through traffic, by widening or coloringshoulders (where people walk), or by installing structures to slow
traffic such as hump (raised road surface) or chicanes (narrowingand adding curves to force vehicles travelling through to swerve

Photo: View of the Public Experiment

to the left and right) or by adding road indicators or constrictions
to keep traffic from entering the sections and their effectivenesswas surveyed.
As a result, a questionnaire survey was conducted, andabout 70% of children using the routes to commute to school
responded, “I can now walk with confidence.” At the same time
as it was confirmed that traffic speed fell in humped sections, italso confirmed that in chicane sections, about half of morning1

traffic slowed to meet and pass oncoming vehicles. And about
40% of the drivers traveling on the streets responded, “I drove
more carefully than usual when I realized it was a school route.”
Based on these results, Tsukuba City has implemented actualcountermeasures. And the results obtained will be used forresearch to spread traffic safety measures for school routes andcommunity streets.

Details * Road Division web site
http://www.nilim.go.jp/lab/gdg/links/syakaijikken.htm■ Opening the Experiment Video Library on the NILIM Website
Planning and Research Administration Department, Research Administration and Evaluation Division

The NILIM has collected videos of various experiments thatit has conducted, and opened the Experiment Video Library onits website.
The NILIM website now includes the Experiment Video
Library that combines videos of experiments and explanationsof research in order to contribute to wider understanding of theactivities and research achievements of the NILIM. The Librarypresents many impressive videos of experiments and easily
understood explanatory videos including a movie of a full-scale
fire test using a wooden three-story school building and a video
explaining congestion countermeasures by linking roadsideinformation with vehicle control technologies.
We will continue to regularly add contents including videos ofexperiments conducted by the NILIM. Please have a look at thispage.

Image: Example of contents of the Experiment Video Library

Details * Opening the Experiment Video Library website
http://www.nilim.go.jp/lab/bcg/videolibraly.html■ Research on methods of improving sustainability of infrastructure management

incorporating the perspective of risk assessment

Maintenance Research Committee

The NILIM established the Maintenance Research Committee
in April 2014. It started conducting the above research that willcontinue for two years starting in 2014 in order to propose
an evaluation method and an evaluation axis (framework) for
infrastructure management bodies to perform self-inspections
to improve the way they conduct management.
Aware that the deterioration of public infrastructure is now aserious problem, many administrators are enacting plans for life
span extension of various types of infrastructure. And they arecarrying out concrete studies of management execution methods
including the building of an inspection, countermeasure anddatabase. In the future, it must find management techniques todetermine how to incorporate execution methods in maintenancework to sustainably conduct the PDCA cycle, and how to prevent
fatal risk to management facilities.
Deciding which basic policies for sustainability of infrastructure
management or risk assessment, for example, preventive
maintenance, restrictions on use, early reconstruction, or corrective
maintenance will be prioritized is likely to vary according to theproperties of the object of management, the organization of themanagement body, and completeness or degree of uncertainty ofthe technologies applied to inspections and countermeasures.
This research will first set a common evaluation axis that should
be applied to actual management work based on an understandingof essential differences between fields while comparing the2circumstances in each infrastructure field.
The completeness of the evaluation axis that is insufficient orrequires improvement will be enhanced with reference to private
sector infrastructure fields and overseas efforts etc. Finally,
through verification using case studies, a framework that allows
evaluation of management methods and provision of knowledge
concerning improvement measures will be proposed.
Organization of present condition and problems facing management
in various public infrastructure fields(From the perspectives of sustainability and risk assessment)
・Concerning physical damage, , human loss and social impact ofdeterioration of objects of management
・Concerning inspections, soundness evaluations, predicting progressof deterioration, countermeasures, and employment of database

Trial preparation of an evaluation axis for management common to
all public infrastructure fields
・Reflecting differences between characteristics of each infrastructure,ability of organization, and reliability of applied technologies
・Reflecting private sector infrastructure fields or efforts thought to beeffective overseas to improve the completeness of the evaluation axis
・Comparison with ISO55000 etc.

Proposing the management evaluation axis and evaluation method(framework)(From the perspectives of sustainability and risk assessment)
・Verification of the evaluation axis that was trial prepared, byconducting a case study

■ Holding the 3rd Joint Workshop (NILIM - KRIHS)
Urban Planning Department

The NILIM held a research exchange conference on urban
affairs with the Korean Research Institute of Human Settlement(KRIHS) on May 24, 2014 to exchange opinions on policy
challenges common to Japan and Korea.
The NILIM signed an MOC (Memorandum of Cooperation) withthe Korean Research Institute of Human Settlement (KRIHS) inNovember 2012, and since that time, they have continued researchexchanges through visits to each otherʼs research institutes. Thisyear, the 3rd Joint Workshop was held at the NILIM and a fieldtour of regional cities was conducted. The results confirmed thaturban regeneration and the restoration of regional cities
are major themes shared by the two institutes.
(1) Holding the 3rd Joint Workshop
After giving presentations at three sessions ([1]Directions of urban regeneration, [2] Improving living
and residential environments, and [3] urban transportationinfrastructures), opinions were exchanged with theparticipation of Professor Tatsuo Akashi of Tokyo City

University (outside commentator). The KRIHS proposed that joint
research be conducted concerning specified cities.
(2) Tour of regional cities
Accompanied by NILIM staff members, they toured Toyama
City and Fukui City, which are representative of regional cities
conducting urban regeneration. In addition to the regional
tour and explanations by city officials, the Korean researchersʼ
understanding of conditions in Japan was further deepened by,providing them with an opportunity to exchange opinions withrailway companies and with NPO that are promoting urban
policies in cooperation with administrative bodies.

The Joint Workshop

Regional Tour (Toyama LRT)

■ Field Survey of Damage to Coastal Facilities in Philippines Caused by Storm Surges ofTyphoon 1330 (Haiyan)

Coastal, Marine and Disaster Prevention Department,Coastal Disaster Prevention Division

When Typhoon 1330 crossed the islands of the southern
Philippines, it triggered storm surge disasters that inflicted
severe damage on Leyte Island and other islands in its path. Oursurvey team conducted a field survey of the damage along thesecoastlines.
The estimated maximum storm surge distribution caused byTyphoon 1330 (Haiyan), that struck the Philippines in November
2013, revealed that storm surges were triggered on the north sideof the path of the typhoon, including Leyte Island, where the most
severe damage was reported. In particular, around Estancia Port on
the east coast of Panay Island, high storm surge deviations between
2 and 4 meters were observed. Therefore, we conducted a joint fieldsurvey on the state of the storm surges and their damage to facilities
on the coast of several points in the path of the typhoon with thePort and Airport Research Institute (PARI) in January 2014.
In Estancia Port, we measured traces of storm surge deviations
with height from 4 to 5 meters. The storm surges and strong
winds caused devastating damage to piers and buildings behindthe coastline. The wooden houses along the shoreline werealmost all damaged by the storm surges, because seawalls andother protection facilities were not constructed.
In Lipata Port, we measured traces showing a storm surge
deviation of nearly 3 meters. Wharves were collapsed by scouring,and passenger terminals were damaged. Many fishing boats
moored along the neighboring beach and the small community
behind them were damaged by inundation of storm surges, byshore erosion due to the storm surges, and by strong winds.

In Tacloban City, many protection facilities along the coastline
were destroyed. Because it was a famous tourist site, RC
construction hotels had been built along the coast, but lower
floors of each hotel were damaged by flow overtopping theprotection facilities.
Before we left the Philippines, we held a meeting to report theresults of the field survey to the Department of Transportation
and Communication (DOTC) of the Philippines.
In Tacloban City, the construction of houses within 40 meters fromthe coastline was prohibited, so the residents would move to highground. But it seems that the moving of the houses has not progressedsince the debris was removed. Now that this yearʼs typhoon season
has started, secondary disasters are feared in the disaster region. Thepeople are eager for the region to be restored quickly.

Figure: Maximum Storm
Surge Distributionof Typhoon 1330
(provided by PARI)

Photo: Damages in Estancia
PortDetails * Coastal Disaster Prevention Division website
http://www.ysk.nilim.go.jp/kakubu/engan/engan/engan1.htm
3

● Schedule of Principal Events
Scheduled Dates

Event NameNovember 15

Open House (Public Works Day), Bridge Contest Awards Ceremony

December 3

2014 Conference of the National Institute for Land and Infrastructure Management● Publication (research achievements) < May, 2014 -July, 2014 >Download from here * http://www.nilim.go.jp/lab/bcg/siryou/index.htm

TECHNICAL NOTE of NILIM
No.

Title of Paper

Names of Divisions

779 Technical notes on design and construction of stucco finished walls for timber
framed residential buildings

Structural Standards Division781 Field Survey of the 2011 oﬀ the Pacific coast of Tohoku Earthquake and Tsunami
on Shore Protection Facilities in Ports (II)Coastal Disaster Prevention
Division

782 Study on Refuge Area Estimation Method under Tsunami Attack in Tokyo Bay

Port Planning Division

783 A Study on Method of Probabilistic Risk Analysis of Airport

Research Coordinator for
Advanced Airport Technology

784 Stated-Choice Analysis to Estimate the Impact of Future LCC Entry
into Domestic Aviation Services in Japan

Airport Planning Division

785 An Analysis of International Passenger Transit Traﬃc

Airport Planning Division

786 The Method of Estimating Gross Origin and Destination International Air-Passenger
Flows

Airport Planning Division

787 Technical Report of Road Safety Measure Planning

Advanced Road Design and SafetyDivision

790 Manual for the calculation of the travel time reliability index value

Traﬃc Engineering Division

791 Method of emergency search for the location of landslide dams and collapses
using high-resolution dual-polarization SAR image interpretation

Sabo Risk-Management Division

794 Report of the Evaluation Sub Committee of NILIM in FY 2013 Evaluation Committeeof NILIM

Research Administration andEvaluation Division● We provide you with research information.
・2014 Annual Report of NILIM
This web site introduces NILIM activities throughout the year, including research activities and achievements,
future initiatives, etc.
Go to this web site: * http://www.nilim.go.jp/english/annual/annual2014/ar2014e.html

National Institute for Land and Infrastructure Management
Ministry of Land, Infrastructure, Transport and Tourism
Asahi 1, Tsukuba, Ibaraki, 305-0804, Japan(Tachihara) Tachihara 1, Tsukuba, Ibaraki, 305-0802, Japan(Yokosuka) Nagase 3-1-1, Yokosuka, Kanagawa, 239-0826, Japan
Summer 2014
TEL:+81-29-864-2754 FAX:+81-29-864-4322
http://www.nilim.go.jp/english/eindex.htm
Edited and Published by National Institute for Land and Infrastructure ManagementNo.49

国 総 研 ニ ューズ レ ター

NILIM News Letter