ICUS/INCEDE NEWSLETTER
International Center for Urban Safety Engineering

Institute of Industrial Science
The University of Tokyo

VOLUME 3 NUMBER 4
JANUARY -MARCH 2004

International Center for
Urban Safety Engineering

STRUCTURAL DAMAGE TO BUILDINGS DUE TO
BAM EARTHQUAKE OF DECEMBER 26, 2003, IRAN
By
Kooroush NASROLLAHZADEH NESHELI*On December 26, 2003 at 01:56:56 GMT (05:26:56 a.m., local time), a destructive earthquake hit Bam City (29.09°
N,
58.35°
E) in Kerman Province, SE Iran. The Bam Earthquake caused numerous casualties (more than 45000 dead) and extensive
damage to different types of buildings. Considering the earthquake focal distance was around 7 km, the buildings in Bam
experienced a near-source earthquake. The majority of buildings were made with adobe and mud. In fact, the worldwide fame of
Bam is due to its historical adobe houses. The most ancient adobe citadel in the world (more than 2000 years old) is located in thiscity and was severely damaged in this earthquake. The other building structural types include: un-reinforced masonry (URM)
building, confined masonry building, steel frame, and reinforced concrete frame. In this article, building damage in terms of theirstructural types is discussed.

Earthquake-damaged view of historical adobe citadel (Arg-e-Bam)page 2Introduction
Regardless of some special
characteristics of the Bam
Ear thquake (e.g. near-source
location of structures), the observed
failures of buildings were very
similar to past earthquakes in Iran.
What has been repeatedly observedis that construction and design do
not conform to seismic resistantcodes. While Iranian code ofpractice for seismic resistant designof buildings (the so-called Standard
No. 2800) was revised by the
Building and Housing ResearchCenter (BHRC) in 1987 and became
mandatory after Roodbar-Manjil
Earthquake (1990), we still face
many newly-constructed buildings
which are not following the code. In
Bam Earthquake, the buildings
which observed main requirementsof Standard No. 2800 could survive,
demonstrating the efficiency of thecode. There is, therefore, a highdemand to establish a system so as
to make sure that the standards
come into effect.
In this article, buildings inaffected areas are classif ied byconstruction material and method,and damage to each structural typeis discussed.
Adobe
Adobe buildings are found in
most areas of Bam city. Thick walls,
h e av y r o o f s , l ow s t r e n g t h o fconstituent materials (i.e. mud) andl a c k o f i n t eg r i t y b e t we e ncomponents are characteristics ofthese houses. As there is no
structural system to resist lateralloads, adobe buildings suffer large
damage in earthquakes. The roofs ins o m e a d o b e b u i l d i n g s we r econstructed in the form of a vault ora dome. Such roofs could partiallysurvive during the earthquake, due
to their special shape, provided thatthe walls support them. However,lack of integrity between roof andwall is a common problem in thistype of buildings, causing totalcollapse of house.
Although the Iranian code

Failure of unreinforced masonry walls and collapse of roof beams
prohibites new construction of
adobe buildings, there is still aquestion about what we can do withthe existing adobe houses, which areextensively distributed in rural areasin the country. It is recommended to
conduct research on developing
effective and cheap retrof itting
techniques for adobe buildings.
Unreinforced masonryT h e wa l l s i n t h i s t y p e o fbuildings are made of bricks and theroofs are constructed by laying
bricks and mud between steel beams(this type of low-rise arch roof iscalled as “Jack Arch” in Iran).
Because there are no confining ties
or other types of reinforcement inthese buildings, they are likely tocollapse during earthquakes. In theabsence of vertical and horizontal
concrete ties, there is no integrity for
an unreinforced masonry building.
Therefore, as lateral forces apply tothe structure, the supporting walls
separate from each other at thecorners of the building and are
subjected to the out-of-plane
deformations. Consequently, theroofs fall due to weak connection
between roof beams and supporting
walls.
Confined masonryThis type of building
demonstrated good seismic
perfor mance. As indicated inStandard No. 2800, in all structural
walls of all masonry buildings, one
or two stories, ir respective ofwhether they are constructed withbricks, cement blocks or stone,
confining ties must be constructed.
Vertical and horizontal confiningt i e s p r ov i d e i n t eg r i t y f o r t h ebuilding and make a seismicresistant structure. By constructing
tie-columns in the main corners of
the buildings, the connection of

Vertical and horizontal ties maintain the stability of building

ICUS/INCEDE Newsletter Vol. 3, No. 4

page 3

Tilt of building due to soft story formed in the first floor
walls at the intersections can be
maintained.
It should be noted that goodseismic performance of confining
ties could be expected only if theties are well executed. In otherwords, the ties with poor quality ofconcrete are not able to develop aseismic resistant mechanism.
I n o r d e r t o h av e a t h r e e dimensional resisting system, tiecolumns should be properly
connected at all intersection points
to tie-beams. If there is no suitabledetailing for reinforcing bars in theconcrete joints, the building can
not stand against earthquakes.
Moreover, the distance between
axes of two successive tie-columns
should be limited to 5 meters
according to Standard No. 2800.
The confined masonry buildings,
which did not observe the abovementioned points, failed during the
Bam Earthquake.
Steel frame
Among steel-framed buildingsin Bam City, those which had a

Separation of
x-bracing elementsfrom the column
due to poor qualityof welding

seismic resistant system by using,for instance, steel bracings in two
orthogonal directions could standduring the earthquake.
One common problem that wasobserved in several buildings in thecity was the formation of softstories. Other problems wererelated to inadequate design andpoor detailing. For instance, theconnection plate of x-bracings tothe beam-column joint did nothave enough dimensions and/or thewelding at the interface of theconnection plate and column was
not adequate. Consequently, thebracings were cut from the beamcolumn joint during theearthquake. This, in turn, led to alateral stiffness decrease of thecorresponding story and caused thechange of the location of ther i g i d i t y c e n t e r, g e n e r a t i n g
additional undesirable torsion to
the building. Another major
problem in steel connections waspoor quality of welding. This camefrom lack of trained workmanshipto perform appropriate welding
during the construction process.

Concrete frame
Reinforced concrete (RC)frames were fewer in number incomparison with the other types ofbuildings in Bam City. These RC
buildings performed relatively wellin this earthquake. Some ofobserved damages were related tobond slip and lack of column
confinement in the plastic hinge.
Conclusions
What has been observed inearthquake-damaged areas in Bam
City was mostly related to “seismic
vulnerability” rather than “seismic
h a z a r d ” . I n o t h e r wo r d s , t h ebuildings suffered much damage
mainly because the structures did
not follow the seismic-resistantcodes of practice. In this regard,
just to have a good code does
not work. What is strongly needed
is to establish a system so as toc o n t r o l d i ff e r e n t s t a g e s o f
construction process including:design, on-site performance,
quality of materials, and so forth.
On the other hand, the problems thatare associated with the existing
structures are mainly related tolack of an effective system forpromoting retrofitting procedures.
Such a system should provide
f inancial incentives for owners
along with economical retrof it
techniques so as to encourage
people to strengthen theirbuildings.
* Scientific Board Member,
Building and Housing ResearchCenter (BHRC), IranICUS/INCEDE Newsletter Vol. 3, No. 4

page 4PROPOSAL OF A NEW ECONOMIC RETROFITTINGMETHOD FOR MASONRY STRUCTURES
By
Paola MAYORCA*
Introduction
Masonr y is a constr uction
material widely used around theworld due to its low cost andconstruction easiness. More than
30% of the world’s population
lives in a house of unbaked earth,which is one type of unreinforced
masonry. During the last century,
human casualties during
earthquakes were mainly causedby structural damage, being the
failure of unreinforced masonry
structures responsible for morethan 60% of them. The
vulnerability of masonry
structures under seismic loads has
been recognized long ago andefforts to provide guidelines forthe construction of soundearthquake resistant houses havebeen remarkable. In spite of this,ev e r y ye a r c a s u a l t i e s d u e t ocollapsing masonry houses during
earthquakes are reported.
Several types of retrof itting
h av e b e e n d e v e l o p e d f o r
unreinforced masonry structures.
For strengthening this type ofhouses in developing countries, a
suitable retrof itting technique
should guarantee not only
its eff iciency in ter ms ofi m p r ov e m e n t o f t h e s e i s m i c
resistant characteristics of thestructure (strength, ductility andenergy dissipation). It should also
be considered that: 1) the usedmaterial is economical and locallyavailable and 2) the required laborskill is minimum. In this context, an ew r e t r o f i t t i n g m e t h o d f o r
unreinforced masonry structures is
proposed.

Retrofitted wall before mortar overlay setting and after test
Proposed retrofitting method
Considering the previously
mentioned conditions, a novel
retrofitting method consisting ofpolypropylene bands (PP-bands)
arranged in a mesh fashion andembedded in a cement mortar
overlay is proposed. These bands
are worldwide used for packing.
They are cheap, resistant, and easy
to handle.
At first, meshes are preparedwith the PP-bands. The pitch andinclination vary according to therequired earthquake resistance.
Then, the masonry wall surfaces
are cleaned and holes are drilled
through the wall at a spacing ofapproximately 4 times the meshpitch. After this, the PP-bandmeshes are set on both wall sides
a n d f i xe d a t t h e b o r d e r s .
Galvanized steel wires are passed
through the wall holes and used to
fix the meshes. The photo below
s h ow s t h e wa l l a t t h i s s t a g e .
Finally, a mortar overlay is placedon the wall surface.
To assess the retrof itting by
PP-band meshes, masonry wallswith and without reinforcement
were constructed and tested inplane.

ICUS/INCEDE Newsletter Vol. 3, No. 4

Retrofitted wall performance
The PP-band meshes have arelatively low stiffness comparedto the masonry walls. Because ofthis, they did not contribute toincrease the wall peak strength.
The mesh contribution was only
observed after the wall cracked.
Immediately after the peak,cor responding to the diagonal
cracking, the unreinforced wallstrength dropped to 10 to 40% of
the peak. On the other hand, thereinforced walls exhibited a 60%
residual strength after the peak,which was sustained for at least
2% lateral drift. In the reversed
direction, the reinforced walls also
exhibited larger post-cracking
strengths. The effect of theconnectors and the mortar overlay
in the wall performance was also
observed in the tests.
T h e s e r e s u l t s s h owe d t h epotential of using PP-band meshes
as an effective and cheap masonry
retrofitting method. Scaled model
houses for testing on a shaking
table are currently been preparedto further verify this technique.
* Post-doctoral fellow,
Meguro Laboratory,
Institute of Industrial Science,
The University of Tokyopage 5A STUDY ON APPROACHES TOWARD BUILDINGDISASTER RESISTANT COMMUNITIESIN CALIFORNIA
By
Miho YOSHIMURA
Recent damaging earthquakes have clearly revealed that retrofitting low earthquake-resistant structures is the key
issue for earthquake disaster reduction. In spite of this, retrofitting activities are not being carried out efficiently
especially for non-public structures in Japan. Some local governments in California, USA are promoting retrofitting more
successfully than Japanese governments by providing various kinds of economic incentives for it. I investigated the current
strategies, history, and clues for successful promotion, mainly in the City of Berkeley and the San Francisco Bay Area,
through interviews and reference collection from Nov. 5 to Dec. 4, 2004. This research was done with the scholarshipprogram for young researchers provided by the US-Japan Cooperative Research Program on Urban Earthquake Disaster
Mitigation by the US National Science Foundation and the Japanese Ministry of Education, Culture, Sports, Science andTechnologies.

The City of Berkeley(104,603 inhabitants) in San
Francisco Bay Area has achieved
several goals to improve building
safety since the 1989 Loma Prieta
earthquake. According to the
Association of Bay Area
Governments, ABAG, the ratio ofretrofitted houses to all singlefamily residential houses is 38%.
The city was honored in 1999
b y t h e Fe d e r a l E m e r g e n c yManagement Agency (FEMA)
with the “Model Community of
the Year Award” for the Project
Impact: Building Disaster
Resistant Communities. Project
Impact is a nationwide campaign
for helping community members
prepare for natural disasters.
More than 90% of the housing
stock in the city is wood-framebuildings. Many of the singlef a m i l y wo o d - f r a m e h o u s e sconstructed before 1945 are notbolted to their foundation or lackwall bracing. Multifamily woodframe residential buildings,
particularly with all or part of the
f irst floor used for parking(structures called “soft-first story
buildings”) have a risk ofcollapse in case of intense
shaking. These buildings needretrofitting.
T h e c i t y h a s p r ov i d e deconomic incentives for
retrofitting these buildings since1991. Its popular prog rams
include the real estate transfer tax
rebate, permit fee waiver andg rant funds or loans to lowincome house owners to retrofit
their homes. Transfer tax is alocal tax imposed by the city on
the real estate exchange. Propertytransfer tax can be rebated up to
1/3 of the 1.5% tax for seismicr e t r o f i t wo r k o n r e s i d e n t i a l
structures or the structures whichcontain two or more dwellingu n i t s . M o r e ove r, p e r m i t a n dinspection fees for retrofit work
are waived by the city in case ofresidential buildings. The total
reduction in the revenue for thecity due to both prog rams
amounts to 1 million dollar
annually. These strategies arever y innovative compared tothose in Japan where retrofitting
incentive prog rams mainly
provide financial assistance andlow interest loan for seismic

evaluation or retrofitting work.
I n a d d i t i o n t o t h e a b ove mentioned measures, the city
library maintains a tool-lending
librar y where community
members can borrow the tools
needed to retrofit their houses.
The city also provides building
r e t r o f i t e d u c a t i o n p r og r a m s
assistedbynon-prof itorganizations. These activities
aim at promoting house owners to
retrofit by themselves.
With slight changes due toadministrative differences, Ib e l i eve t h a t t h e r e i s a l a rg e
benef it of adopting similar
strategies in the Japanese systemthat have proven so successful inpromoting private b uilding
retrofit in California.

Soft-first story building

ICUS/INCEDE Newsletter Vol. 3, No. 4

page 6
Welcome to Dr. Amano,
visiting Professor

ICUS welcomes its new staff
Dr. Reiko Amano, who has
j o i n e d I C U S a s a Vi s i t i n g
Professor from February 2004.
Dr. Amano is a Deputy General
Manager of the Kajima
Corporation, Tokyo. Here, we
present a self introduction of Dr.
Amano for our readers.

I have been working for
Kajima Corporation since 1980.
My specialization is in designof different types of bridges. I
h av e b e e n e n g a g e d i ndevelopments of various typesof bridges using latest PC (Prestressed Concrete) technology
as a designer, a researcher and aconstruction manager. In 1986,
one of our main works, Birdie
Bridge, a stressed-ribbon typebridge using the composite
material with concrete and FRP,
received Tanaka Award from theJ a p a n S o c i e t y o f C iv i lEngineers (JSCE). Another of
our works, “The Seismic Design
Method for PC Bridges withHigh Pier”, which was adopted
to Washimi Bridge, received

JCI Technical Award in 1989.
During my stay in Indonesia
from 1997 to 1998, I concluded
my doctoral dissertation basedon my research experiences ofd ev e l o p m e n t s o f u n i q u estructures, and proceeded toobtain doctoral degree from the
University of Tokyo in 1999. In
recent years, my major concerns
are environmental protection
systems and f ire preventions y s t e m s . L a s t y e a r, wed ev e l o p e d a u n i q u e f i r eprevention system called “Water
Screen System”, which can be
adoptedtos u b way s ,underg roundh i g h w ay s ,underground shopping arcades
and so on.

ICUS Activity Records･Prof. Yasuoka delivered a lecture
at AIT and carried out a fieldsurvey at Sri Samrong, Thailand
together with Dr. Endo (Feb 2428).
･ Prof. Meguro carried out adamage investigation survey of
Bam earthquake together with Dr.
Yoshimura (Feb 16-26).

･Prof. Ooka attended the annual
meeting of AGS in Sweden (Mar29-28).
･ P ro f. D u t t a v i s i t e d A I T fo r
collaborative research at RNUS
(Feb 10-Mar 31) and carried out
G P S s u r v ey a n d f i e l dinvestigation for a research
project in Sri Lanka (Feb 14-22).

･ D r. K a t o, D r. E n d o a n d D r.
Yo s h i m u ra v i s i t e d A I T fo r
collaborative research at RNUS
(Mar 11-13), and visited India forresearch investigation related to
RNUS (Mar 14-17).
･Dr. Endo carried out a field survey
related to eucalyptus in Chile(Mar 21-29).

3rd International Symposiumon Urban Safety Engineeringon Octorber 18-19, 2004
ICUS is going to organize the
3 International Symposium on“New Technologies for Urban
Safety of Mega Cities in Asia”
jointly with the Indian Institute ofTechnology Kanpur (IITK), India.
The symposium will be held inAgra, India during October 18-19,
2004. The symposium will focus
on the following areas;- Safety assessment of existing
infrastructure- Seismic rehabilitation andretrofitting of structures- Planning and development ofurban infrastructurerd- E nv i r o n m e n t a l i m p a c t o furbanization- Advanced technologies forassessment of urban safety
The various deadlines for paper
submission and registration are as
follows:- Submission of abstract:
June 30, 2004
- Notif ication of acceptance:
July 15, 2004
- Submission of full paper:August 15, 2004
- L a s t d a t e o f r eg i s t r a t i o n :September 15, 2004

ICUS/INCEDE Newsletter Vol. 3, No. 4

Dr. Sudhir Misra, an Associate
Professor of IITK, is the Secretaryof the Organizing Committee. He
can be contacted for further details
in the following address:
Dr. Sudhir Misra
Department of Civil Engineering,
IIT Kanpur
Kanpur 208016, India
E-mail: usafety@iitk.ac.in
http://icus.iis.u-tokyo.ac.jp/isus04/
Tel: (+91-512) 259-7346
Fax: (+91-512) 259-7395

page 7

News from Regional Network Office of ICUS/AITin Thailand
The Regional Network Officefor Urban Safety (RNUS) has
initiated a series of seminars at
AIT from the beginning of 2004
on various issues emphasizing
new technologies for urban safety
a n d s e c u r i t y b y i nv i t i n gresearchers and experts working
in these areas. A total of four
seminars have been organized
during the last three months.
The f irst seminar was
delivered by Dr. Takahiro Endo on
February 24, 2004 on applicationsof Hyperspectral Remote Sensing.
Dr. Endo, a Lecturer of ICUS,
University of Tokyo, Japan, spoke
to a packed classroom about thebasics of hyperspectral remotesensing and its usage. One of themain focuses of his presentation
was application of hyperspectral
remote sensing in estimation ofdamaged concrete for urban
safety.
Then on 27 February 2004,
RNUS facilitated the organizationof the 2nd Seminar on “Remote
Sensing from Local to Global
Scale.” The presentations were
given by Prof. Yoshifumi Yasuoka
who talked on “New Technical
Trend in Remote Sensing – Its
Application to Civil Engineering”
a n d b y D r. D e n n i s D y e w h o
discussed “Photosynthetically
Active Radiation and theTerrestrial Carbon Cycle”. In thes e m i n a r, t h e t wo s c i e n t i s t spresented recent scientif ic
d eve l o p m e n t s i n t h e f i e l d o fremote sensing and its
applications in civil andenvironmental engineering. Prof.
Yasouka is the Deputy Director
General of the Institute ofIndustrial Science under theProf. Y. Yasuoka and Dr. D. Dye during their talks at the Seminaron March 12, 2004 at AITUniversity of Tokyo. Dr. Dye is
the Group Leader of the
Ecosystem Change ResearchP r og r a m , F r o n t i e r R e s e a r c hSystem for Global Change, Japan.
On March 2, 2004, RNUS
organized a seminar on“Numerical Models in Fluid andT h e i r A p p l i c a t i o n s ” b y D r.
Ke i s u ke N a k ay a m a , a S e n i o r
Researcher of the National
Institute for Land andInfrastructure Management,
Japan. In his presentation, Dr.
Nakayama discussed the various
types of numerical models which
can be applicable for modeling of
ecological system in bay areas ofcoastal cities. A case study ofTokyo bay was presented in his
lecture. He applied various
numerical methods and conductedlaboratory tests to understand thef l ow f i e l d a n d s t r a t i f i c a t i o nphenomenon in Tokyo bay, andpredict the ecological system.
D r. Yo s h i t a k a K a t o , a n
Assistant Professor and Ms. Miho
Yoshimura, a Research Associateof ICUS, the University of Tokyo,
delivered talks at the 4th seminarof the series organized by RNUS
at SCE, AIT on March 12, 2004.
D r. K a t o t a l k e d o n r e c e n t
problems and maintenance ofconcrete structures in Japan. He
elaborated some of the major
problems encountered by theJapanese civil engineers inevaluating the concrete structuresusing Non Destructive Inspection(NDI). He introduced a new NDI
technique, which can beeffectively used to deal with thecurrent problems. Ms. Yoshimura
introduced a new Retrof itting
Promotion System (RPS) for low
earthquake-resistant structures inearthquake prone countries that
could serve as driving forces forthe promotion of retrof itting of
weaker structures. She mentionedthat the effectiveness of the RPS
was verified on the basis of therecovery activity data after the
1 9 9 9 Ko c a e l i e a r t h q u a ke ,Istanbul, Turkey and through thisprocess, several advantages forboth governmental and citizensides were identified.

ICUS/INCEDE Newsletter Vol. 3, No. 4

page 8
Editor’s Note
Since 2002, ICUS has
been holding international
symposium on urban safety
every year. The 2nd symposium
was held in Japan in October2003 and the upcoming 3rd
symposium would be held in
India in October 2004. I visited
India with my colleagues Dr.
Endo and Ms. Yoshimura for a
preparatory meeting of thiss y m p o s i u m i n M a r c h . We
a r r i v e d a t D e l h i a ro u n dmidnight and went to Agra, thecity famous for the Taj Mahal,
by car the following morning.
T h e d i s t a n c e o f j u s t ab o u t
200km took around 5 hours totravel. During this journey,
among many other things, I

could feel the variety ofdifferences between Japan andIndia. For instance, maintenancesituations of infrastructure, traffic
rules, and so on. I believe that thedifferences in these practices
d e p e n d o n t h e d i f f e re n c e s
between the cultures and sense ofvalue of each country ands i m i l a rly
i n f ra s t r u c t u r emaintenance in a country is also
closely related to its culture. So,
we should never enforce our rules
in a partner country as they are
when we support infrastructuredevelopment in a developing
country. It is extremely importantto understand the culture and thesense of value of that country.
I C U S s e t u p t h e reg i o n a l
network off ice at AIT (Asian
Institute of Technology) in 2002.

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

Since then, Dr. Dutta has beens u c c e s s f u l l y wo rk i n g o n
c o l l a b o ra t i v e p ro j e c t s i n
cooperation with researchers in
Thailand. Dr. Dutta recieved a
M.Eng. from AIT and a Ph. D.
from the University of Tokyo. So,
despite being an Indian, he iswell versed with the cultures ofThailand and Japan. However,upon reaching here, I find that I
d o n o t k n ow t h e c u l t u re o f
Thailand at all. I believe the levelof my understanding of the Thai
culture would ultimately affectthe level of success of myresearch in Thailand. So, my firststep in Thailand would be
towards learning the Thai culture
and to try and work and think likea Thai.
(by Kato)

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