ICUS NEWSLETTER
International Center for Urban Safety Engineering

Institute of Industrial Science
The University of Tokyo

VOLUME 6 NUMBER 2
JULY-SEPTEMBER 2006

International Center for
Urban Safety Engineering

HIDDEN CAVITIES UNDER THE GROUND- THEIR CAUSES AND CONSEQUENCES By
Reiko KUWANOHIDDEN CAVITIESUNDER THE GROUND
You may think that the ground isfirm and solid, unless some natural
disasters like earthquake or landslide
occur. But this is not always the case.
Sometimes, you may be standing on
an underground pitfall covered withsolely a layer of pavement, which
may collapse without a clear sign of
warning. The photos below show asinkhole that appeared on a road,caused by failure of a sewer pipe lying
underneath, on the left, and a muchlarger cave-in, about 30 m wide and 3

m deep, which occurred in Tsu-city,
Mie Prefecture in July 2006, on theright. The cause of this huge hole has
not yet been clarified, although it issuspected that numerous old small
pits and tunnels for mining sands inthis area, an activity that stopped morethan 20 years ago, are the most likely
responsible.
In most cases, a cavity in soil
precedes such a sudden collapse ofground surface. The origin of thecavity could be natural or artificial.
When the stability of the cavity islost for any reason, soil above thecavity falls causing loosening ofA cave-in due to failure of a corroded sewer pipe

surrounding soil. The loosened area
spreads up until the surface collapse
eventually occurs.
POTENTIAL SOURCES
OF UNDERGROUND CAVITY
We h ave l a i d va r i o u s
infrastructures, such as tunnels,
trenches, water pipes, sewer pipes,
gas pipes and others, deeply
underground. In order to catch up
with the growth of urban populationand functions, construction of thoselifelines has rapidly progressed in the
recent decades. The cur rent
underground situation is congested
and complicated. All the undergroundlifelines are potential sources ofcavities when they are too deteriorated
to support the surrounding soil. Oldabandoned mines and tunnels and air-A cave-in of 30 m wide and 3 m
deep affected road and residents.
(Photo courtesy of the Tsu
Municipal Government)

The number of cave-in on roadpage 2

Relationship between
the average age of sewer pipes in 23
wards in Tokyo and the numberof cave-in incidents (after“Prospects of Sewerage 2001”
Tokyo Metropolitan)

History of sewer pipe construction in 23 wards of Tokyo(after the website of the Ministry of Land and Infrastructure)raid shelters are the most dangerous
sources of underground cavities as they
are likely to be poorly supported andtheir locations are not well recorded.

could be discovered even years later.
Developing underground mapping
information seems to be necessary tofundamentally sort this out.

CAVE-IN DUE TO FAILURE
OF SEWER PIPESRESEARCH ON THE
MECHANISM OF GROWTH
OF CAVITY AND SOIL
LOOSENING

Recently, approximately 1000
cave-ins on roads occur every year due
to the failure of sewer pipes in the urban
area of Tokyo, within the 23 wards.
Especially areas, where the urbanization
started early and the existing sewer pipes
are old, are suffering from frequent
cave-ins, as shown in the figure on theupper left corner of this page.
Damage to old deteriorated sewer
pipes appears to be the major source ofsoil cavities leading to cave-ins in earlier
developed cities. Looking at the historyof sewer pipe construction in Tokyo
depicted on top right corner of this page,
we note that the situation will soon
become more serious.
Tokyo metropolitan government aswell as other local governments are wellaware of this problem and carrying out
various actions for the eff icientmaintenance of existing sewer pipes.
Their efforts include systematicreconstruction of old pipes and early
detection of damage to pipes or cavities
in soil, both of which apparently
contribute to prevent further increase in
the number of cave-in.
In fact, the reasons for the damage
to sewer pipes are not only age. It wasreported that around 15% of sewer pipe
failures in Tokyo were caused by“other” construction works. The photos
on the right show sewer pipes broken bywater pipes. Such sewer pipe failures
are not always noticed immediately, andICUS Newsletter Vol. 6, No. 2

Whatever the reason is, once aburied pipe is broken, surrounding soil
will be disturbed. This will loosen the
ground and when the disturbancereaches the ground surface, local
settlements will appear. Rainfalls seemto accelerate the process, judging fromthe fact that larger number of cave-ins
occur in rainy seasons, from spring toautumn. The difficulty is to answer
more specific questions. How fast does
the initial disturbance reach the surface?
How can we identify the dangerous
void/cavity which will grow bigger? If
we find a small defect in a pipe like athin crack, do we need to worry?
Unfortunately, the basic mechanismof the formation of initial voids in soil
and the growth of cavity resulting in theeventual ground surface cave-in has notbeen well understood yet. The author

and her colleagues investigated thisphenomenon by small scale modelexperiments, results of which are shownin the figure on the top left corner of thenext page. The main findings from thestudy were:- Even a small crack or gap (5 mmwide) is sufficient to cause a cave-in.
- In sandy soils, an initial small void
can quickly grow, especially when
the ground is saturated. Above acavity in sand, a loosened partlargely develops where the dry
density decreases by approximately
10 to 20 %.
- For sands with fines, which arecommonly used for backfillingsewer pipes in practice, the rate ofcavity growth seems to be slower. A
loosened part, where almost half ofthe soil is lost, develops above acavity, but it is not considerablylarge. A schematic diagram isdisplayed in the next page.
- In order to prevent soils from being
washed away and form a cavity
even in case a sewer pipe is broken,
it is ultimately necessary for soil
particles to be bonded to each other.
Even, weak bond is enough for the
purpose.

A water pipe passing through anexisting sewer pipe,
found under a cave-in

A water pipe broke an existing
sewer pipe, found undera cave-inpage 3

X-ray CT image of cavity andloosened area in sand obtained
from a small scale model test

Typical patterns of cavity andloosened area developedin sandy ground
Sand is the least resistible
material. The content of fine fraction
improves the situation although not
for a long time. Soil around a cavity
loses confinement and when it issaturated, soil particles would yield
to water. Thus, a heavy rainfall
significantly affects the process ofcavity growing. The figure on the
top-center of this page is an X-ray
CT scanning image, showing acavity and loosened area formed in asmall model sand chamber. Above acavity of only 5mm in size, theloosened area vertically spreads andreaches the surface. When thishappens in the actual ground, theloosened area masks the small cavity
underneath and its detection by radar
exploration may become difficult.

lowered, local people found the holeapproximately 2 to 4m wide and 1m
deep.
Under the hole, at a depth of
15m, a water pipe of 2m diameter
had been constructed by shieldtunneling method. The front of thetunnel had passed the location of thecave-in more than 6 months before.
Yet, there was no indication that thetunneling work excavated too muchsoil, equivalent to the hole size.
Because the profile of the groundwas sand/gravel with cobbles,
conventional sounding techniques,
like standard penetration test (SPT)or cone penetration test (CPT) could
not be successfully applied. In fact,
the SPT, that had been carried out
before the tunnel construction,
recorded an N-value over 50 bysimply hitting large cobbles. A radar
exploration was performed to searchfor cavities and loosened parts inrelatively shallow ground, up to adepth of 3m. A new sounding
technique measuring the resistancewith drilling was also carried out toexplore deeper sectors up to a depthof 15m. Although there was noapparent cavity, the ground above thetunnel was found to be noticeablyloosened all along. The loosened
area was constrained to only above
the tunnel, which is not usually
expected in tunneling works. All theholes, cavities, and loosened areas
were filled/grouted securely, not toaffect the safety of the river bankwhich was adjacent.
TOWARDS FUNDAMENTAL
SOLUTIONS
Thus, a cave-in is mostly a manmade disaster. Once we open a spacein the ground, it should be properly
maintained. When we decide toabandon the man-made space, it
should not be left unfilled. A cavity
in the ground grows and creeps
upward in silence, then with sometrigger, which in many cases is arainfall, it suddenly appears on thesurface. Currently, the problem ofcave-ins is not prevented but mainly
a d d r e s s e d o n c e i t o c c u r s bytemporarily filling up the holes.
Several aspects should be considered
to fundamentally sort this out,
including developing techniques fore a r ly d e t e c t i o n o f d a n g e r o u sunderground cavity/looseness,
proper and efficient maintenance ofunderground pipes, and developing
f illing materials and bur yingtechniques which are not washedaway in case a pipe is deteriorated.

Downstream

CAVE-IN WITHOUT AN
APPARENT CAVITY
A cave-in sometimes occurs
w i t h o u t a p r e c e d i n g c av i t yformation. The photo on the rightshows a hole that appeared in a flood
plain along a river. Due to heavy rain
brought by a typhoon, the level ofriver water rose and inundated theplain for a day. After the water level

A hole appeared in a flood plain along a river(after the website of the Ministry of Land and Infrastructure)

ICUS Newsletter Vol. 6, No. 2

page 4UTITU Workshop was held in Istanbul
UTITU Ordinary / Emergency
Workshop 2006 was held in Istanbul
Technical University (ITU), Istanbul,
Turkey during the week of September
10-16. Both Istanbul and Tokyo areseismic prone areas. This workshop
was one of the activities among thejoint study project together with ITU
and the University of Tokyo (UT).
The objectives of the workshop wereenhancing the strategic approach forthe regeneration of Galata region,
the historical site in the central
business district of Istanbul. It wasorganized to be an educationalseminar for 17 students from ITU
and 12 students from UT. The

students were divided into threegroups. After having a f ield
excursion, they discussed new imageof public space in their target area
during both ordinary and postearthquake emergency situations.
They surveyed current problems andfuture possibility in the area during
the f ield excursion. Finally,
regeneration plans were proposed
integrating four research interests:
urban design, urban history, water
engineering and earthquake disastermitigation engineering. This
workshop was a valuable opportunity
not only for the integration ofdifferent researches but also forJapanese and Turkish students
discussing plans

Final presentation

exploring new educational strategies
for urban regeneration.
(By M. Yoshimura)

Evacuation plan proposedusing 3D-GIS data

Field excursion in Galata areaby students

Disaster-preparedness drill held at the University of Tokyo Hospital
As informed in Newsletter Vol.5,
No.4, 2006, a project team wasformed to consider the role of The
University of Tokyo Hospital at atime of a disaster. ICUS members
are now investigating the social
demands of a disaster base hospitalsuch as the number of patients afterlarge-scale disaster.
T h e U n ive r s i t y o f To kyo
Hospital conducted a comprehensive
disaster-preparedness drill on
September 8, 2006. ICUS members
and students of Meguro laboratory
joined and supported the drill.
T h e d i s a s t e r s c e n a r i o wa s
conceived by Dr. Yoshimura tosimulate an actual large earthquake
disaster; the drill was planed in orderto adapt the scenario. Dr. Kanada
designed a central administration
tool for disaster headquarter. Thise n a bl e d t o d i s p l ay i m p o r t a n t
information such as damage tofacilities or triage results on a large
screen.
Confirmation of the safety of
hospital inpatients and facilities was
carried out just after earthquake.
Nurses permanently reported thesituation to the disaster command

Disaster command center

Simulated patient

ICUS Newsletter Vol. 6, No. 2

Triage training
center. The hospital headquarterdirector decided to accept outsidedisaster victims after judging thefacility capability from the collected
information.
S i m u l a t e d p a t i e n t s we r etransported in ambulances and triage
training was carried out in front of
the hospital main entrance.
A simulated press interview
meeting was held after the drill andthe director commented on theexercise outcome. All processes werefilmed with video cameras and ad o c u m e n t a r y DV D w i l l b ecompleted in the near future.
(By H. Kanada)page 511th Open Lecture was held
The 11th ICUS Open Lecture washeld at IIS in the afternoon of
September 25, 2006. The title of thelecture was “Risk Management of
Building Sanitation” and reported theachievements of the research project
under the same name which is
supported by the Japanese Ministry of
Health, Labour and Welfare. About 80
people attended the lecture.
Four speakers delivered thefollowing presentations:- Dr. Koichi Ikeda, Director of the
Department of ArchitecturalHygiene and Housing, National
Institute of Public Health of Japan,
and Project Leader, explained the
project outline and “Riskmanagement of hygiene forarchitectural equipments”.
- Prof. Shinsuke Kato, Director of theCenter for Development ofInstrumentation Technology, IIS, theUniversity of Tokyo, delivered thetalk: “Diffusion of hazardous agentsin buildings”.
- Dr. Masaki Itoh, Chief of the Water

Supply Planning Section,
Department of Water Supply
Engineering, National Institute of
Public Health of Japan, gave thespeech: “Ensuring drinking watersafety in buildings”.
- Dr. U Yanagi, Chief of the Health
Housing Section, Department ofArchitectural Hygiene and Housing,

National Institute of Public Healthof Japan delivered the lecture:“Countermeasures for bio andchemical terrorism in buildings”.
Finally Professor Kimiro Meguro
of ICUS made concluding remarks andexpressed gratitude to the participants.
(By R. Ooka)

Lecture by Dr. K. Ikeda

Lecture by Dr. M. Itoh

Lecture by Prof. S. Kato

Lecture by Dr. U Yanagi

RNUS Activities
RNUS Seminar
On August 9, 2006, RNUS
organized a seminar on “Analysis
and Treatment for Corrosion of
Reinforced Concrete Structures.”A group of researchers from
Kanazawa Institute of Technology
led by Associate Professor Shinichi
Miyazato and Associate Professor
Mitsuharu Tokunaga kindly
delivered lectures to AIT students
and staffs.
The seminar was composed offour presentations, three wereabout the corrosion of reinforcement
in concrete structures and one wasabout a three-dimensional

measurement method using remotesensing technology.
After the seminar, guests from
Kanazawa Institute of Technology
visited the RNUS office as well as thelaborato r y o f t h e S t r u ct u ra lEngineering Department anddiscussed RNUS activities.

Dr. Kato gives a memorial gift
to Dr. Shinichi Miyazato
for his kind presentation

Group photo of presenters,
students and staffs of StructuralEngineering after RNUS Seminar

Special Presentation on the
Utilization of Expansive Concretefor Higher Cracking Resistance ofStructure
On September 26, 2006, Dr.
Sahamitmongkol held a seminar on“The Utilization of Expansive
Concrete to Prevent Cracking inConcrete Structures.” The audience
i n cl u d ed u n d erg ra d u a t e a n dgraduate students of the Department
of Civil Engineering and Technology,
Sirindhorn International Institute ofTechnology.
RNUS Staff Served
as Local Organizing Committee
of EASEC-10
Dr. Kato and Dr. Sahamitmongkol
were assigned by Prof. Worsak
Kanok-Nukulchai as part of thelocal organizing committee of the10th East Asia-Pacific Conferenceo f S t r u c t u ra l E n g i n e e r i n g &Construction (EASEC-10).
I n i t i a t e d 3 0 y e a r s a g o,
EASEC-10 is the biggest conference
related to structural engineeringand construction in the Asia-Pacificregion. There were more than 700
presentations and more than 850
participants.
(By R. Sahamitmongkol)

ICUS Newsletter Vol. 6, No. 2

page 6

THEOS: An eye in the sky for development of Thailand
Since the introduction of remotesensing technology to Thailand in theearly years of 1970’s, the world has
witnessed tremendous advance in boththe technology itself and also theapplications. As a developing country,
Thailand has been following suchdevelopment with great interest and has
committed resources to tap on thebenefit of this technology. In November
2000, a new public organization was set
up by the Royal Thai Government(RTG) to engage in remote sensing andgeographic information system.
Geoinformatics and Space Technology
Development Agency (GISTDA) is
thus a specialized organization with theobjectives of maximizing the benefit of
3S, namely, remote sensing, GIS and
GPS for national development.
In July 2004, GISTDA signed thecontract agreement with EADS
Astrium of France in Bangkok to build
and launch Thailand’s first earth
observation satellite: Thai Earth
Observation System (THEOS). The
project will take 30 months to complete
at a cost of 128 million euros to theThai Government. It is scheduled to belaunched in the second half of 2007.
Although this is a commercial
undertaking, nevertheless, THEOS was
initiated under the umbrella of the ThaiFrench Government Agreement on
Space Technology Development. As

such, several projects are being
implemented to support the long term
exploitation of space technology. For
example, the training and hands-on
experience of 20 Thai engineers at thecompany factory in Toulouse, France
and a series of joint cooperative
application are being implemented withsatisfactory results.
THEOS is a sun synchronous, polar
orbiting satellite with a designed life
time of 5 years. The main
characteristics are as follows.

Several countries have expressed
their interest to access to THEOS
within their footprints. Therefore,
THEOS will not only contribute to thedevelopment of Thailand, but also toother regions of the world. The Thaigovernment has also expressed its

THEOS spacecraft(image credit: EADS Astrium)
intention to offer THEOS data to thedisaster mitigation efforts under theInternational Charter. It has always been
the RTG’s policy to abide by the
Principles of the Exploitation of Outer
Space for the benefit of mankind. Since
admitted as a full member of theCommittee on the Peaceful Users ofOuter Space (COPUOS) in 2005,
Thailand has been participating actively
in two subcommittees (Scientific andTechnical Subcom and Legal Subcom)
as well as in the main COPUOS.
Besides applications in agriculture,
land use planning, forestry andenvironmental assessment, etc. THEOS
will be used in the integrated urban river
basin management, urban flood disasterprevention and mitigation and urban
sprawl planning.
(By Dr. Suvit Vibulsresth
Executive Board Member andFormer Director, GISTDA)

Establishment of BNUS at BUET and it’s Activities
A contract has been signed toestablish the Bangladesh Network
Office for Urban Safety (BNUS) at
BUET, Bangladesh between Prof.
Dr. Md. Mazharul Hoque, The
Head, Department of Civil
Engineering, BUET and Prof. Dr.
Taketo Uemoto, The Director,
International Center for Urban
Safety Engineering, Institute ofIndustrial Science, the University ofTokyo in June 14, 2006. The main
objective of this office will be topromote and enhance high quality
cooperative research in areas
related to urban safety.
BNUS office comprise of fourrooms at the fifth floor of Civil
Building, BUET. The current BNUS

members are Prof. Dr. Mehedi - Evaluation of concrete bridges
and flyovers of Dhaka
Ahmed Ansary, Dr. Munaz Ahmed
Noor, Ms. Israt Jahan, Mr. Md. - Development of indigenous
instruments for reinforcement
Yasin, Mr. Qumruzzaman and Mr.
detection
Qurban Ali. BUET has already
Please visit BNUS website atprovided a space for BNUS in its
http://www.buet.ac.bd/BNUS/
webpage.
(By M. A. Ansary
The current and future activities
Professor, BUET)
will be as follows:- Evaluation of concrete structuresof Bangladesh (already done for
BUET buildings in June 2006)- S ch o o l e a r t h q u a k e s a fe t y
program (Launched in September
2006)- Seismic evaluation of lifeline
infrastructures- Evacuation plans for different
BNUS office at the 5th floor,
wards of Dhaka city
Civil Building, BUETICUS PARTICIPATION – IIS OPEN HOUSE

ICUS Newsletter Vol. 6, No. 2

page 7

Dr. Sanae Miyazaki joined ICUS
D r. M i y a z a k i g o t h e r
undergraduate degree from theTokyo Institute of Technology (TIT)
in 1988 and has worked for NTT
DATA Corporation since then. She
also got her Ph.D. degree from the
TIT in 2000.
Dr. Miyazaki research interest is

Dr. Sanae Miyazaki

in remote sensing technologies,e s p e c i a l l y s a t e l l i t e re m o t esensing and sensor network
systems. Her recent researchtarget is the data fusion analysis
using various sensor data fordisaster management.
(By T. Uomoto)

ICUS Director is the first visitor at Chula Unisearch IIS Branch Office
As agreed in the Memorandum ofUnderstanding signed between
Chulalongkorn University and theInstitute of Industrial Science (IIS), theUniversity of Tokyo, on March 21,
2006, the Chula Unisearch IIS Branch
Office was officially opened at the
beginning of July 2006.
On August 7, 2006, Prof. Taketo
Uomoto, Director of ICUS became thefirst visitor of this IIS Branch office.
On this occasion, Prof. Uomoto

discussed with Associate Professor
Boonchai Stitmannaithum, Associate
Dean of the School of Engineering, thepossibility of collaborative research
activities between ICUS and the Facultyof Engineering, Chulalongkorn
University.
Located in the central Bangkok, thisbranch office of IIS will serve as aneasy-to-access business center for IIS
professors who visit Bangkok for theirresearch activities. The communication

facilities (internet and local telephone)
as well as other office supplies are well
prepared for the visiting IIS professors.
(By R. Sahamitmongkol)

ICUS visitors and Dr. Stitmannaithum
at Chula Unisearch IIS Branch Office

ICUS Activities• Prof. Uomoto attended the 10th East
Asia-Pacific Conference on StructuralEngineering and Construction held in
Bangkok, Thailand, during Aug. 2-8
together with Dr. Kanada. Prof. Uomoto
also joined Shotcrete for UndergroundSupport X held in Vancouver, Canada,from Sept. 11 to 17.
• Prof. Meguro attended the 1st European
Conference on Earthquake Engineeringand Seismology in Geneva, Switzerlandfrom Sept. 3 to 7. Dr. Mayorca joined thesame conference from Sept. 3 to 8. Prof.
Meguro took part in a Center Of
Excellence action study workshop
carried out at Istanbul, Turkey during
Sept. 10-18. Dr. Yoshimura also
participated in this workshop from Sept.
9 to 20.
• Dr. Oki participated in the observation
at Beijing Site in Beijing, China from
Jul. 30 to Aug. 3. He joined The United
Nations-Sigma Xi Scientific Expert

Group on Climate and Sustainable
Development/World Water Week held at
Washington DC, USA and Stockholm,
Sweden. He attended the IPCC WGILL
Meeting held at Cape Town, South
Africa from Sept. 8 to 16.
• Visiting Professor Reiko Amano
attended the 12th International
Symposium on Aerodynamics andVentilation Vehicle Tunnels in Portoroz,
Slovenia from July 11 to13.
• Dr. Kato stayed at AIT for his research
work and teaching duties at RNUS
during Aug. 1-18 and Sept. 3-Oct. 5.
• Dr. Kanada attended the 6thInternational Symposium on
Nondestructive Testing in Civil
Engineering held at St. Louis, US from
Aug. 13 to 20.
• Dr. Sahamitmongkol stayed at AIT for
his research work and teaching duties
at RNUS during July 12-Aug.16,
Aug.20-Sept.14, and Sept.19-Dec.13.

• ICUS Seminar was held at
Kawaguchi-ko during July 14-15.
• The RC-39 Committee met on July 25.
After the meeting Prof. Ura delivereda speech on “Autonomous
Underwater Robot for ObservationFrom Kamaishi Bay breakwater
offshore to Myojin reef caldera.”• Prof. H. Wiggenhauser, Director of
the Federal Institute for Materials
Research and Testing, Germany,
visited ICUS on July 30• A delegation of 18 professors from the
National Kaohsiung First Universityof Science and Technology of Taiwan
led by Prof. Tai-Ping Chang, visited
ICUS on Aug. 15.
• Former Visiting Prof. S. Hayashi was
appointed President of the JapanFoundation for Regional ArtActivities on Sept. 1.
• ICUS Open Lecture was held on
Sept. 25.

AwardsApplied Element Method.”• Mr. Ramesh Guragain from Meguro•
Dr. Kanada and Mr. Pakawat
Laboratory obtained the Furuichi
Sancharoen from Uomoto Laboratory
Award on September 29 for his
got the Incentive Award for Excellent
excellent Master Degree Thesis entitledPaper at the 2006 Annual Meeting of“Numerical Simulation of Masonry
the Japan Concrete Institute for their
Structures under Cyclic Loading using

papers “Componential Analysis byPortable Fluorescence X-ray
Analyzer” and “Life Cycle
Repairing Cost Considering
Uncertainties of Deterioration
Prediction Model,” respectively.

ICUS Newsletter Vol. 6, No. 2

page 8
Editor’s Note
The existence of the global
warming problem has been confirmedby recent research results, eventhough some researchers still doubt
about it. It is expected that natural
disasters such as flood and typhoon
will become more and more frequentand hazardous in the future. The
reduction of CO2 emission is urgent
for prevention of global warming.
However, it is not readily progressing.
Energy and drug consumption are
similar in the sense that human beings
become addicted to them and cannot
easily get rid of a living style based onthem once they get accustom to it.

Currently, some holy human lives aretaken by the struggle for energy.
The necessity of paradigm shift
from a life of quantity to a life ofquality has been recognized for morethan 20 years. Unfortunately, this shift
is not moving ahead because people
do not have a concrete image of their
future quality of life and thus noconsensus has been reached among
them. As a result, the global warming
problem is not been addressed .
Incidentally, ICUS women staffs
further increased with the arrival of
Dr. Miyazaki. Currently six ladies
belong to ICUS: one Professor, two
Associate Professors, two Research
Associates, and one Secretary. They

If you would like to contribute an article to ICUS newsletter orhave any comment or suggestion, please contact the editorialcommittee at icus@iis.u-tokyo.ac.jp.
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
E-mail: icus@iis.u-tokyo.ac.jp
http://icus.iis.u-tokyo.ac.jp/

International Center for
Urban Safety Engineering

are very active in their fields asevidenced in the main article of thisnewsletter which was written by oneof them: Dr. Reiko Kuwano. Men
have been the main contributors tomaterial civilization up to the present.
However, they have not paid muchattention to the quality of life. I believethat women ideas and senses will begreatly useful to shift from a life ofquantity to a life of quality in the
future. Therefore, I am looking
forward to the continuation of theactive participation of ICUS women
staffs.
(By R. Ooka)

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