I C U SNewsletter
Volume 12

Number2

Jul. to Sep. 2012

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

Nankai Trough earthquake: latest damage estimation
By
Kimiro Meguro
Professor and Director, International Center for Urban Safety Engineering
Institute of Industrial Science, The University of Tokyo
The Japanese Cabinet OfficeCentral Disaster Prevention Council's
working group for promotion ofdisaster countermeasures of the
Nankai Trough gigantic earthquake
released a notable report on August29, 2012. It is a detailed damage
estimation in case of future possible
Nankai Trough earthquake, basedon the “Great East Japan Earthquake
and Tsunami Disaster” due to the“off the Pacific coast of Tohoku
Earthquake” on March 11, 2011. This
preliminary report outlines expected
damages if a series of five quakes
should happen continuously andsimultaneously in Tokai, Tonankai,
Nankai, Eastern Kyushu Island, andthe tip of the crustal plate.
Recentfiguresinhazardassessments tend to be raised eversince seismologists and experts

failed to predict the Tohoku
earthquake with moment magnitude(Mw) 9.0. However, even before
this earthquake on March 11,
2011, Japan had already entered aseismically active period, facing
danger of massive earthquakes
occurring within the coming three
to five decades. As for this area off
the Pacific coast of Tohoku, experts
had pointed out the possible threat

Figure 1 D istribution of structural damage due to M9 class Nankai Trough Earthquake: No. of buildings and houses collapsed
or burned down

of “offshore Miyagi Prefecture
Earthquake”, about M7.5, centeredunder the Pacific coast of Miyagi
Prefecture, with 85% probability
in the next two decades, and even
99% in the next three decades.
Although, the quake that actually
hit offshore Miyagi Prefecture andits surrounding areas in 2011 wasgreater than expected -- as massive
as M9 --, there had always beencommon awareness about its highprobability: 90% for M7.1 to 7.7class earthquake in the region of
Northern off Sanriku in the next
three decades, 70-80% for M7.7
quake near the southern trench off
the Sanriku coast in the next two
decades, and 90% for M7-classevent offshore Ibaraki Prefecture in
the next three decades. Obviously,
Tohoku coastal region had been
waiting to be hit by huge earthquakes
anytime.
The “Great East Japan Earthquake
and Tsunami Disaster”, brought onby strong ground motions and killer
tsunami, still continues to impact
the entire nation, both deeply andextensively. The tragic disaster hastaught us the real fear of a devastating
earthquake, and warned us of theimportance of preparation for properdisaster countermeasures.
Where large-scale earthquakes
have historically occurred

Yet, we must keep in mind that
another region in Japan is in dangerof a similar or even larger earthquake
disaster: a zone along the Nankai
Trough, an oceanic trench thatstretches off the coast of the island of
Honshu. The Nankai Trough marksa plate boundary that is caused by
the slip of the Philippine Sea Platebeneath the Eurasian Plate, on top ofwhich the regions of Kinki, Shikoku
and Kyushu are located.
In the past centuries, quakes
have frequently occurred in thiszone. Past well known events
include: Keicho (1605, about M8),
Hoei (1707, M8.7), Ansei Tokai(1854, M8.4) and Tonankai (1854,
M8.4), Showa Tonankai (1944,
M7.9) and Nankai (1946, M8.0)

earthquakeearthquakes.
Some experts say that the 2011
M9-class event has made crusts
around Japan increasingly unstable.
In any case, we have to admit thata huge earthquake is likely to occur
along the Nankai Trough in the near
future. Here I show the overview ofdamage estimations and the effects
of disaster countermeasures.
Latest Predictions

The maximum earthquake that may
happen along the Nankai Trough is
expected to be Mw 9.1. Several
fault models have been considered tosimulate different types of damage,due to ground motion or due totsunami. Also, by changing thelocation of asperities that generatestrong ground motions and large slip
areas that induce large tsunami, four
different cases of damage, in which
the extent of disaster largely differ
by region (Tokai, Kinki, Shikoku
and Kyushu), have been estimated.
When these predictions cometrue, very strong ground motions

Table 1 Estimated damage due to M9 class earthquake
predicted along Nankai TroughFigure 2 Newly anticipated Nankai Trough earthquake fault

Source: Cabinet Office, Government of Japan
Figure 3 Estimated seismic intensity (left) and tsunami height (right) due to possible M9 class Nankai Trough earthquake

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ICUS Newsletter Vol. 12, No.2

estimated to be between 2.364 and2.386 million. Figure 1 represents
one example of damage distributions.
The estimation of deaths are between
226 and 323 thousand, and injured
between 610 and 623 thousand
respectively as Table 1 shows.
Tables 2 and 3 indicate that theselatest estimations represent larger
figures when compared to the actual
damage by the 2011 East Japan
Earthquake and Tsunami Disasterand the 2003 estimation on Nankai
Trough (covering Tokai, Tonankai
and Nankai earthquakes) by theJapanese government.
The recent preliminary reportrefers to only human casualties anddamage to buildings and houses.

measured 7 in Japan Metrological
Agency (JMA) seismic intensity
scale -- the highest out of 10 JMA
levels -- will strike ten prefecturesand 151 cities, towns, and villages,
in addition to intensity 6+ in 21
prefectures and 239 cities, towns,
and villages. Very huge tsunami
waves are also expected to reachabove 20 meters in 8 prefectures asshown in Figure 3. Some parts ofthe three major metropolitan areas,
Tokyo, Nagoya and Osaka, will bedamaged while critical distribution
route between east and west of Japan
may be cut.
Consequently, the total numberof buildings and houses that might
be collapsed or burned down isTable 2 C omparison of damage by newly anticipated Nankai Trough worst-case scenario
earthquake and the “2011 East Japan Earthquake and Tsunami Disaster”
Magnitude※1

Inundationarea

2011 East Japan

9561km2

Newly anticipatedNankai Trough9.0（9.1）

Comparison rate

Population in
inundation area
About

620,000

Dead / missing

Buildings collapsed
or burned down

About 18,800※2 About 130,400※2

1,015 km2 ※3 About 1,630,000※3 About 323,000※4 About 2,386,000※5
1.8

2.6

17

18

Table 3 C omparison of damage by newly anticipated Nankai Trough worst-casescenario earthquake and 2003 damage estimation of Tokai, Tonankai and Nankai
earthquakes
Magnitude※1

Inundationarea

Population in
inundation area

2003 estimation of
Tokai, Tonankai,
Nankai quakes

8.7（8.8）――

Newly anticipatedNankai Trough9.0（9.1）

Comparison rate

Dead / missing

Buildings collapsed
or burned down

About  24,700※6 About 940,200※7

1,015 km2 ※3 About 1,630,000※3 About 323,000※4 About 2,386,000※5
―

―

13

2.5

Source: Cabinet Office, Central Disaster Management Council, Committees for technical investigation on
countermeasures for the Tonankai and Nankai Earthquakes (Sept. 17, 2003)※1: Figures in parenthesis show tsunami scale Mw (moment magnitude)※2: Based on announcement by the headquarters for emergency disaster control on June 26, 2012.
※3: Projected inundation areas are based on that all levees and water-gates are functional in case of quakes.
※4: D isaster estimation on the following conditions: Damage in Tokai region becomes severer, midnight in winterseason, with wind speeds of 8m/s.

※5: D isaster estimation on the following conditions: Damage in Kyushu region becomes severe, evening in winterseason, with wind speeds of 8m/s.
※7: Disaster estimation at 18:00 pm.

※6: Disaster estimation at 5 am.

Table 4 Damage estimation before and after countermeasures
Weather condition: winter season
with wind speeds of 8m/s
Basic scenario
quake happening in
landward scenario

Total collapse of residences
EstimateddamageEstimateddamage withcountermeasures

Death toll
Estimation

Estimation withcounter-measures

midnight

970,000

310,000

266,000

60,000evening

1,210,000

437,000

226,000

32,000midnight

2,380,000

800,000

323,000

105,000

evening

1,820,000

520,000

278,000

59,000Source: Cabinet Office, Government of Japan

Estimation of other damage, i.e.
lifeline utilities, traffic facilities,
daily living difficulties, disaster
waste, economy and other aspects
are to be released at some otherstage.
Issues and countermeasures

The largest crisis is when tsunami
attacks shortly after strong groundmotions -- people in many areas
cannot move and have no time toevacuate. Nevertheless, experts
point out that the possibility of suchhuge earthquake and tsunami is very
low, suggesting that appropriate
evacuation and countermeasureswould help to greatly reduce thedeath toll as shown in Table 4.
It is extremely important tomaintain a correct sense of crisis,
and to take accurate measures.
Table 4 shows that we must further
improve “implementation of disaster
resilient built environment”. That
is to say, we must further increase
quake-proofing of houses andbuildings, flame-resistant products,
emergency
evacuation
areas,
people's consciousness to evacuate,
total evacuation framework, andmany other issues. By drawingout maximum effect, damage candrastically be reduced: building
damage down to one third of
the estimated figure, and humancasualties down between one
seventh and even one third.
Yet, we must keep in mind all
damage cannot be prevented. The
scenario of more than 30 thousand
deaths and 300 thousand totallycollapsed buildings still remains.
We should remember that the latest
estimations exceed the damages
due to the 1995 Kobe or the 2011
East Japan earthquakes by far. We
need to establish a total disastermanagement system, and start
making preparations for recovery
ahead of disaster.

ICUS Newsletter Jul. to Sep. 2012

Page 35th Joint Student Seminar on Civil Infrastructure:
Bangkok, Thailand
By Y. Takano, master student, Nagai Laboratory

The 5th Joint Student Seminar
was held in Bangkok, Thailand, on
Aug. 20-21, 2012. The seminar wascomposed of two parts: presentation
session and field trip.
On the first day, presentation
session was held at Chulalongkorn
University, where 2 keynote speakers
and 16 students delivered talks ontheir research in different fields:
disaster information collection,
numerical simulation, transportation,
geotechnology, concrete,andreconstruction from the Tohoku
Earthquake. These presenters belong
to universities in Thailand, Korea
and Japan, representing countries
such as Thailand, Korea, Indonesia,
Ethiopia, and Japan. The inspiring
discussions further broadened myParticipants spent two productive days in Bangkok

interest and knowledge on civil andurban engineering.
The next day, we enjoyed the tour
to King’s Palace and Chao Phraya
River. At the Palace, we learned
about the history of Thailand. Alongthe river, we could still see the scars
left from the serious flood last year,
but also witnessed some signs ofrecovery. I hope the seminar next
year will be just as successful andworthwhile.

Analytical investigation of RC anchorage failure:confined by 3D RBSM transverse bar
By Y. Takano, master student, Nagai Laboratory

Nowadays in Japan, seismic designcode is becoming more stringent.
To fulfill strict requirements,
larger reinforcement must be
applied, leading to the increaseofreinforcement
congestion.
Therefore, the bond performanceof the congestion part needs to beclarified.
Simulations were carried out

Reinforcement congestion at beam-column joint

Result of analysis (cracks on surface and inside)

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ICUS Newsletter Vol. 12, No.2

to study relationship of bondperformance with failure mechanismof reinforcement and concretearound the anchorage zone ofstructural elements. To analyze
anchorage failure, “3D Rigid Body
Spring Model (RBSM)” was used.
The objective was to confirm theeffects of transverse reinforcement
in enhancing anchorage.
The simulation has confirmed theeffect of transverse bar, which showed
a good match with the experiment
data in terms of anchorage capacity,
crack patterns and failure modes.
Internal crack propagation was also
simulated.
For this research work, Yoshiyuki
Takano received the Best Presenter
Award at the 5th Joint Student
Seminar.

BNUS: earthquake and fire hazard assessment
Ward 65, Dhaka
By Prof. M. A. Ansary, BNUS

Ward 65, or so-called ‘Puran
Dhaka’, is situated in the old partof Dhaka City in Bangladesh. This
area is unique in its land use pattern.
Mixed-type land use, along withhigh population density, has madethis area vulnerable to earthquake
and fire hazard. Bangladesh Network
Office for Urban Safety (BNUS) has
conducted a number of surveys toassess vulnerability of the importantfacilities in this area
There is a total of twenty two
essential facilities in Ward 65,
including mosques, schools, acollege, community centers andclubs. Among these, eleven facilities
have recently been surveyed by
BNUS. Several non-destructive
testing (NDT) techniques have been
carried out to assess the earthquake
vulnerability of the buildings.
Microtremor and Ferro scanners

have been used as the tool for NDT.
Fire hazard vulnerability has also
been assessed, using the Community

Vulnerability(CVAT).

Assessment

Tool

Hazi Abdul Latif Mosque
Location of important facilities

Assessment activities

15th WCEE: exhibit and presentation
By M. Numada

The 15th WCEE (World Conferenceof Earthquake Engineering) was heldin Lisbon, Portugal, on September
24-28, 2012.
ICUS exhibited a booth, showcasing
its main activities. A number ofvisitors, including researchers,
engineers, and business people, cameto share our ideas and information.

ICUS exhibition booth

Many took keen interest in the
introduction and overview of ICUS,
particularly in our basic policy andapproach in sustainable management

in urban environment and risk
reduction.
We showed a video of the 2011
Tohoku disaster, filmed by ICUS
members, monitoring the recovery
and reconstruction progress overtime. This footage, along with ourbriefing, helped to deepen visitors’
understanding of the situation in thedamaged areas.
Also on display was the PP-band
retrofitting technology for nonengineered masonry structure. The
availability and the applicability ofthis technique captured participants’attention. Not only visitors from Iran,India, Pakistan, Indonesia or othercountries where a large number ofmasonry houses stand, but also thosefrom the technologically developed

nations, such as the US or the EU
countries, expressed positive interestin this research.
Each member of ICUS gave apresentation on their own research
theme in oral, e-poster, and posterstyle. We are delighted and proudof the good performance at bothWCEE.
WCEE is held every four years.
The venue of the next conference in2016 is Santiago de Chile.

Explanation about PP-band
technology activities

ICUS Newsletter Jul. to Sep. 2012

Page 5

24th ICUS open lecture:
sharing present challenges of Fukushima
By T. Kato

The 24th ICUS open lecture washeld July 28 at the IIS Convention
Hall, the University of Tokyo.
The theme was "Sharing Present
Challenges
ofFukushima",
organized jointly with the Japan
Society of Urban and Regional
Planners (JSURP).
Fukushima is stepping towards
recovery, yet moves are still smalland slow. The entire country
must come together to overcome
the crisis. People from different
standpoints gathered to share acommon understanding on theongoing problems.
Kicking off the discussion,
Mr.
MutsuoAnzai,
PolicyAdministrator,
Revitalization
Bureau for the Evacuation Areas
Fukushima Prefectural Government,
chronologically reviewed the actionsof national/local governments.
Mr. Akira Tamagawa, working

at Namie Town Office, Fukushima,
reported on victims’ current reality.
Ms. Miharu Takamura from
Minami Soma looked back on her
painful experiences of evacuation
and refuge, raising questions on the
support system.
Dr. Kyoji Hoshino (Professor
Emeritus, Fukushima Universy;
Director, Fukushima NPO Network
Center) spoke about the social
significance of NPOs, public
administrations and welfare councils.
The closing speaker was
Dr. Hiroshi Suzuki (Professor
Emeritus, Fukushima University;
Chairman, Fukushima Prefecture

Reconstruction Committee) who
focused on temporary relocation ofmunicipalities away from disasterhit regions.
Participants rediscovered thehardships in Fukushima, particularlyin the Futaba hazard area, and also
re-realized the continuous need forsupport.
The lectures were held as thethird of the series of “Sharing
Experiences” symposia, organizedjointly with JSURP. The first (May20) and the third (July 28) was held
at ICUS, while the second (June 16)
was in Tokyo and the fourth (Sept29) in Kobe.

Panelists in heated discussion

Samanthi Hewage, Kuwano Lab master student,
receives Furuichi Award
By R. Kuwano

Ms. Samanthi Renuka Indiketiya
Hewage, a graduate student of the
Civil Engineering Department,
the University of Tokyo, received
the Furuichi Award 2011 for her
outstanding master thesis study. The
prize is awarded to the excellent
master thesis of the year in the Civil
Engineering Dept. At the graduation
ceremony on September 27, theprize was handed to her by Professor
Junichi Koseki.
Ms. Hewage conducted her master
research under the supervision of Dr.
Kuwano. She performed a series ofexperiments to evaluate the looseningof soil around underground cavities.
Currently available techniques toPage 6

Samanthi Hewage
congratulated by Prof. Koseki

detect subsurface cavities still face
many limitations -- they only identify
air-filled voids separated from soil.
Also, the maximum of accurately
detected depth is limited to only a
few meters; in the case of clayey
and high moist soils, it is further
limited to around 1 meter. That is
why detecting cavities in deeper

ICUS Newsletter Vol. 12, No.2

grounds is extremely difficult. But if
a cavity continues to upsize towards
the surface, ground subsidence isinevitable.
Since air-filled cavities in general
are associated with the loosening
process of the surrounding grounds,
it is easier to find loosened soil first
and then look for nearby cavities.
Thus, even cavities hidden deeper
can now be detected by capturing
signs of loosened areas on thesubsurface. This way, accuracy andefficiency of the current methods
will improve at a reasonable cost.
The first objective of this study was
to figure out the extents of loosening
in relation to the cavity size, and also

to identify the parameters which
affect scale and rate of loosening.
Artificially loosened soil was
produced in the laboratory. Throughtwo-dimensional model tests, cavity
was expanded by water infiltrationand drainage. Effects of cavity size,
density, ground compaction and rateof drainage on soil loosening andcavity expansion was observed.
As the second objective, quantitative
study on mechanical features ofloosened soil was conducted.
Evaluationwas made by triaxial
tests, while the influence ofcondition change was experimented:
density, cavity size and location.

Loosening above artificially createdcavity in soil

Furthermore, the extent of loosening
was studied by X-ray CT scan,so as to compare the differenceof behavior in two- and threedimensional responses. Results
obtained from the two dimensionalmodel tests show that the height of
the loosened area extends up to fivetimes that of the cavity height while

radial expansion is limited whencompared to vertical expansion.
As a conclusion, it was foundthat subsurface cavities are more
vulnerable to cave-ins, and thatloosening expands to at least
twice the height of cavity. Overall
stiffness of the ground may decreasesignificantly even by a very small
void.
Hidden ground cavities may leadto large and dangerous groundcave-ins. The outcome of this study
will serve as an important clue indeveloping a novel technique todetect cavities and thereby prevent
ground sinking.

Farewell to Dr. Takahiro Endo
By K. Meguro

Research Associate Dr. Takahiro
Endo retired from ICUS in Oct. 2012
to join the GOSAT-2 (G2) ProjectPreparation Team, National Institutefor Environmental Studies.
Having joined ICUS in Apr. 2003,
Dr. Endo was committed to thedevelopment of LiDAR simulation

system for forests, and served in the“carbon dynamics of Amazonian
forest (CADAF)” project, a JSTJICA program.
ICUS thanks Dr. Endo for his
contributions and wishes him all thebest with his new position.
Dr. T. Endo

ICUS Activities July – September❖ Professor Haruo Sawada andDr. Takahiro Endo attended
Carbon Dynamics of Amazonian
Forest in Brazil Aug. 4–26. Dr.
Endo also attended the XXⅡ
Congress of the International
Society for Photogrammetry andRemote Sensing in Melbourne,
Australia, Aug. 27–Sep. 3.
❖ Dr.
Takaaki Kato visited
Nanjing, China, Jul. 11–20
to attend Japan-China Joint

Meeting on Comprehensive
Disaster Prevention Planningand Standards for Disaster
Prevention Design.
❖ Dr. Akiyuki Kawasaki was at
AIT in Bangkok, Thailand, July
31–Sep. 14, and again from
Sep. 30–Oct. 7. He also visited
Yangon Union of Myanmar Sep.
6–8 on a collaborative researchwith Yangon Technological
Univ., the Japanese Embassy

and JICA.

❖ Dr. Muneyoshi Numada visited

Jakarta and Banda Aceh,
Indonesia, Jul. 21–26, to lecture on
PP-band retrofitting technology.
❖ Professor Kimiro Meguro, Dr.
A. Kawasaki, Dr. M. Numada
and Dr. Shinya Kondo traveled
to Lisbon, Portugal, for the 15th
WCEE from Sep. 22–29.

Awards and Honors❖ Professor

Mikio Koshihara
received the World Monuments
Fund/Knoll Modernism Prize in

Sept. 2012, awarded by World
Monuments Fund.
❖ Ms. Samanthi Hewage won the

Furuichi Award for her master
research summarized on pages 6
and 7.

ICUS Newsletter Jul. to Sep. 2012

Page 7

Editor’s note…
Since the Fukushima nuclear
power plant accident broke out
in March 2011, we have become
more conscious of electricity usage.
Particularly during the summer
season, we at IIS had to make every
effort in minimizing peak power
load and reducing total consumption.
Air conditioners were kept fixed at
28 degrees centigrade. Room lights
were mostly turned off in daytime.
Some old refrigerators in offices

were replaced by latest energyefficient models. By accumulatingthese small efforts, IIS has managed
to achieve satisfactory level ofelectricity savings. It seems that wehave somehow accustomed to the
new life style of using minimum
electricity.
On the other hand, we knowthat people in general do not liketo sacrifice comfort or economic
growth. Also, as pointed out inthe main article, we must hasten
to prepare for the possible giant

earthquake which may strike in thenear future. Many difficult tasks still
lie ahead. We can only overcome
such challenges by social strategy
development and engineering
technology innovation. We, theICUS members, need to continue
making efforts by working together
with colleagues around the globe,
thereby contributing to the safety ofurban system.

By R. Kuwano

USMCA 2013: Oct 9-11 in Hanoi, Vietnam
The 12th International Symposium on New Technologies for Urban Safety of Mega Cities in
Asia (USMCA 2013) will be held in Hanoi, Vietnam on October 9-11, 2013. Check out the
ICUS website for latest information. 
http://icus.iis.u-tokyo.ac.jp/en/

International 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.