page 1

ICUS/INCEDE NEWSLETTER
International Center for Urban Safety Engineering

D

US

RS

IN

IT Y

OF

OF

TE

TO KY

O

I N S TIT U

Institute of Industrial Science
The University of Tokyo

TR

IA L

S C IE

N CE

THE

UN

IV

E

VOLUME 1 NUMBER 2
JULY - SEPTEMBER 2001

International Center for
Urban Safety Engineering

Traditional Architecture in Saint Lucia
and Seismic Responses
By

Anne L. D. French
Deputy National Disaster Coordinator, Saint Lucia

INTRODUCTIONSaint Lucia is an island country
located in the southern section ofan archipelago of volcanic islands,
which comprise the Lesser Antilles.
The island is about 500 km northof Venezuela and is 616 km2 in size.
A mountain range forms the backbone of this volcanic island with thehighest point at Mt. Gimie (height=1040m).
The island is 30 km long and ismade up of pliocene to recent
basalts and andesitic basalts, which
originate from largely unknown
and strongly dissected centers. Thismeans that the island is made up
predominately of igneous rock. The
other rock type to form the island
is sedimentary. This type of rockshows distinct layering and can befolded or fractured by movement of
the earth's crust. The stratificationand layering of permeable and impermeable beds is frequently responsible for slope instability.

Over 43% land of the island has
a gradient of more than 30o. As a result, much of the island's structures
are on stilts. This design feature ispopular for its ability to provide additional storage on the underside or
to allow for expansion at a later date.
SEISMIC ACTIVITY
IN SAINT LUCIAThe Caribbean plate runs throughGuatemala in Central America to theeast between Jamaica and Cuba,around Hispaniola and Puerto Ricoin the Caribbean, joins the boundary east of the Caribbean islands andfollows the archipelago. In theSouthern Caribbean near Trinidad,
the eastern boundary joins the southern boundaries along the pacific sideof Central America.
Tectonic plate boundaries are notneatly cut lines of activity, but dispersed zones of movement. Of thethree types of motion: 1) sliding pasteach other; 2) converging and 3) di-verging where the plates moveapart; the islands of the eastern Caribbean, are an example of plates
that are sliding past each other.
The Caribbean plate is moving
slowly eastward, in relation to theNorth and South American plates.
These plates are made up of land(continental crust) and ocean (Atlantic Oceanic crust) masses. As
the Atlantic Oceanic crust is denser
than the Caribbean crust, the Caribbean along the eastern Caribbean
chain of island is driving down the
Atlantic. This movement gives rise
to earthquake and volcanic activity. The primary cause of damage
to buildings by earthquake resultsfrom the ground shaking which is
generated by the movement of tectonic plates.
The historical records of Saint
Lucia contain many references totremors and earthquakes felt by theisland as the written records coin-

ICUS/INCEDE Newsletter Vol. 1, No. 2

page 2Rodney Bay Gros
Islet

Grande Cul de Sac Bay

PUERTORICONORTH AMERICA

Babonneau
La Caye

LeewardIslands

Anse la Raye

SAINT LUCIA

Canaries

PraslinSoufriere

Choiseul

SAINT
LUCIA

MicoudDesruisseaux
Choiseul
Hewanorra Intl. Airport

Viexu Fort

SOUTH AMERICA

Maria Island

Location Map of Saint Lucia
cided with the arrival of Europeans in the mid 1600s. Although, theinstrumental records are less than
100 years old, and they carry strong
evidence of seismic activities in theregion.
Damage due to earthquakes israther small in Saint Lucia whencompared to other neighbouring islands. A quick examination of past
events indicates that Saint Lucia's
concern should be for the cumulative effects of frequent tremors.
History shows that the island is notexempt from major earthquakes. A
7.0 magnitude earthquake had hit
the island on February 16, 1901,
another earthquake of magnitude
7.5 occurred on March 19, 1953.
In recent period, between 1990 to
1995 the island has experienced
continuous earthquake activity
with the highest registering earthquake of magnitude 4.5 on May 19,
1990 (refer to the tables in the rightside and next page).

salfataric and funarolic activity has
continued at a fairly constant level
through historic time.
The one-recorded incidence ofgreat disaster was observed in 1789.
It seemed to have been a small
pheratic eruption. Because the last
explosion of this volcano dates backover 20,000 years ago, it is consid-

ered less likely to erupt in the near
future as in the case of volcanoes
in Saint Vincent, Martinique andGuadeloupe.
Despite the lack of recent explosive activities, there is evidence ofactivity at shallow depths below theregion. This gave rise to the occurrence of several earthquake activi-

Earthquakes of magnitude 3.5 and above occured between February
1990 and November 1995 in Saint Lucia

VOLCANIC HAZARD RISK
The most active volcanic centeron the island is the Qualibou
Caldera, which is located in theSouthwest. This Caldera wasformed over 35, 000 years ago.
There are several volcanic domes
within the Caldera Region. The
only site of historic activity is at
the Sulphur Springs. All descriptions of this area indicate that

ICUS/INCEDE Newsletter Vol. 1, No. 2

Year

Month and dateMagnitude

1990

February 5

4.0

1990

May 194.5

1990

May 23

3.6

1990

July 2

3.5

1990

July 25

3.5

1991

July 18

3.9

1991

November 27

3.5

1992

May 5

3.8

1992

September 20

3.6

1992

September 20

3.6

1992

November 1

3.5

1993

July 30

3.7

1993

September 23

3.7

1994

January 5

3.6

1995

March 5

3.7

1995

November 8

4.3

1995

November 25

3.8

page 3ties through out the decades. The
most recent one started in May
1990 and went on afterwards forabout 14 months.
Several thousand people actually
live within the Caldera and a few
km away from the Soufriere
Springs. The population of
Soufriere at the 1990 census was
7683. The vulnerability factor
therefore is high. The hazards
posed by the volcano are all associated with its violent eruptions.
EXISTING HAZARDMONITORING SYSTEMThe Seismic Research Unit in
Trinidad maintains four high sensitivity seismographic stations on
the island. While Le Observatoire
Volcanoloqiue de la Montagne
Pelee in Martinique maintains one
station. These are sufficient to detect initial abnormal conditions. Bymeans of this system, the relevant
authorities can be provided with advanced notice so as to evacuatethreatened population.
TRADITIONAL
ARCHITECTURE
The traditional architecture,
though lacking in pretensions, arecollectively a monument no lessimportant to a once strong nativebuilding tradition which we havevirtually lost. The architectural tradition of Saint Lucia and her sister
islands come from many sources
through a long period.
One of the main sources was
Amerindian people. Amerindians
were sea faring people. The modern fisherman's hut, canoe, fishingnets and baskets of Saint Lucia are
all influenced by Amerindian culture. Their construction style madetheir houses cool, rainproof andflexible, which were the elements
needed on an island that can experience constant earth tremors, sweltering heat and hurricanes. This
construction style is referred to as"fuchette en terre" this is where a'Y' shaped piece of wood was dug

deep into the ground and the 'Y' end
support the roof.
Next comes the influence of Europeans. The time frame of influenceof the Europeans ranges approximately from 1600 to 1950. This covers about three hundred and fifty
years of European architectural influence. Saint Lucia became morevaluable as the years went by, mainly
because of the magnificent natural
deep-water harbor at Castries, which
was and still is protected on threesides by hills. Today the areas surrounding Castries are dotted with numerous military buildings. These
once impressive and imposing structures have been converted and absorbed into civilian life.

The earliest Churches on the island were usually built of timberwith a thatch roof and stone paved
floor, reminiscent of Amerindian
construction. These Churches
were damaged or destroyed by thedevastating hurricane of 1780 except the Church at Dauphin,which was constructed of stone.
The Churches were rebuilt usingstone to resist hurricanes and theearth tremors. Despite this precaution, cracks occurred in many
Churches due to tremors.

Not long after the Europeans
settled themselves in the Caribbean, the slave trade began. The
Africans were discouraged frombringing with them their languages, religions, music or anyThe main building material of his- thing remotely cultural. In reviewtorical structures in Saint Lucia were ing the architectural aspect of thestone. They have withstood wars, island's African heritage, it is a
fires, hurricane and earthquakes. miracle that anything remotely
However, the combined onslaught African remained to influence
has begun to have an effect on the society. At the time of emancipation, many of the slaves were not
structures.
Earthquakes of 1990 in Saint Lucia

Month and dateMagnitude

February 5

4.0

March 18

3.0

April 16

3.3

May 183.4

May 194.5

May 233.0

May 23

3.6

June 1

3.3

July 2

3.5

July 7

3.9

July 25

3.5

August 1

3.2

August 25

3.4

September 9

3.3

September 30

3.2

October 13

3.3

October 25

3.2

October 26

3.0

November 4

3.0

ICUS/INCEDE Newsletter Vol. 1, No. 2

page 4
directly from Africa, but born andraised in Saint Lucia. In 1838,
when slavery was finally and completely over, two-thirds of Saint
Lucia was under virgin soil belonging to the crown. Land was readily
available for the people for construction.
The hillside houses (known as
Tapia) evolved and remains an
identifiable feature in Saint Luciansociety. These structures are madeof timbers. Small saplings made theframe of the structure while mature
trees were held in place by the deadweight of the structure, forming thefoundation. The splitting of further
trees provided the cladding. The
floor, which is also of timber, israised slightly off the ground to allow for ventilation of the beams
and to avoid moisture penetration
while accommodating the gradientof the island. The material of
choice was timber not stone, as timbers were readily available. Without the proper tools, stone is a difficult material to manipulate, whiletimber is fairly malleable and canresist both hurricane and earthquake forces. As time moved on,
hand cut saplings were replaced bymachine cut lumber and piles ofstones were replaced by concrete
blocks or reinforced columns. Individual lots became hamlets andthen communities. With each newbuilding erected, the design of thestructures became more sophisticated. Interestingly, timber remained the material of choice. The
Tapia dwelling can be seen almost
everywhere on the island, from
Gros Islet in the north to Vieux Fortin the south, even in developed areas such as Castries.
With the advent of modernism,
many buildings on the island aremade of reinforced concrete withflat roofs and large glazing. The
design of most of the office buildings in Saint Lucia are influenced
by this modern style. Due to large
destruction of hurricane Allen August 1980, the Saint Lucia had tobe rebuilt in a short period. Due tothe short period of constructions,many schools were constructed ofpre-stressed concrete slabs. Most ofthese new buildings were groundfloor structures, which are considered to be relatively safer during anearthquake. However, many of the
new buildings in the city are of reinforced mass concrete erected on reclaimed land. These new buildings
are very much vulnerable to earthquake and soil liquefaction.

RECOMMENDATIONS
A disaster upsets infrastructureand ecosystems and puts strain on
the already limited resources of adeveloping State like Saint Lucia
and her citizens. Such a situation
can set dangerous precedents of dependency and underdevelopment.
Sustainable development for a society like ours is not possible without addressing the damage done todevelopment as the result of a disaster, particularly earthquakes incase of Saint Lucia.

PROBLEMS
The tendency to build on reclaimed land is increasing in Saint
Lucia, although the trend is not yet
rampant. Such land heightens
ground movement e.g., the vibrations of heavy goods vehicle can be
felt by the occupants of nearby structures. Therefore, the effects of anearthquake on structures placed onsuch soil are magnified many times
over.

How one responds to or during
an earthquake is not something to
be decided during the event. Preplanning or preparedness is the key.
Mitigation against any disaster requires cooperation. As such, there
should be cooperation between social, economic and political actions
from local, regional and international governments. Also the communities and their corresponding
groups can play an important roleand so must be encouraged to takepart in such actions.

Destruction from earthquakes inSaint Lucia could be worse than it isat the moment given the lack of seismic design standards for virtually all
construction. Added to this deficiency is the probability of major
landslides being triggered by thesequakes.
Another concern is design ofstructures in areas prone both to hurricane and earth tremors, with two
kinds of movements. Hurricane
forces move in a horizontal fashion
while earthquake forces move in a
vertical fashion. It is difficult to design a structure for both. Therefore,
despite the inevitable earth movement, Saint Lucians have decided
that the annual hurricane season,
from June to November, is more ofa threat. Despite statistics, which
could prove otherwise, the reality ofSaint Lucia's situation is that residents do not consider the island as "earthquake country" and therefore
they design for the perceived threat
from hurricanes and not from earthquakes.

ICUS/INCEDE Newsletter Vol. 1, No. 2

Some approaches that can betaken to mitigate earthquake effects
are:Culture: The mitigation activities
of a community must be acknowledged and incorporated into any action plan. Many people execute a
tradition without knowing why.
Traditional buildings have the ability to withstand both earthquake
and hurricane forces. In addition towhich it is cheap and easy to build
and in many cases, this is the mainconcern of individuals. Mass concrete or concrete blocks replace
many timber structures as thesematerials are perceived as stronger
and are used as a measure of anindividual's financial success.
Information: It must be ensured
that the public is aware of alternate
traditional construction practice,
emergency plans, what they entail
and what their role is in the plan.
Attempts have been made to edu-

page 5cate and inform the various publics
on response actions to an event.
One must ask though is it enough?
Does the public know how to react
during an earthquake? Creating theposters and flyers and distributing
them may not necessarily mean thatthe message is being perceived or
received. Sectors such as the media, construction industry, schoolsetc., must be sensitised. Is interest
in an event only triggered by theevent? In other words, will members of the population only be interested in earthquakes the nexttime a series of quake occurs?
Preparedness: It must be acknowledged that the successful management of a risk is dependent on thelevel of preparedness of the area tobe affected. Many craftsmen are
still available in the community andare willing to hand down the skills
as they were handed down to them.
This should be encouraged.
Cooperation between Sectors:
Disaster Managers need to be incorporated into the planning process while Planners should be involved in disaster reduction in aneffort to forge a closer working relationship for a more comprehensive and holistic approach to development.
Development Control: The examination of landslide prone areas
should become a material consideration for developments. Environmental Impact Assessments (EIA)

are already required for certain developments, however governmental
EIA for state property would provide
a representation of the risk factor of
the area under consideration for development.
Landuse: Development of areas
should be based upon hazard andmitigation plans. Development inhigh-risk areas should be firmly discouraged. Should such land need to
be developed, it should be reservedfor projects considered as least critical facilities.

Insurance:Insurance should be related to the level of hazard underconsideration and the mitigation
steps being taken. The important
issues such as proper considerationof building regulations in structure
design are to be incorporated ininsurance policy. Such policies will
motivate people to adhere the strictbuilding design codes in construction practice.

Building Codes: In the absence ofa national building code, a suitablecode for interim use is the Caribbean
Uniform Building Code (CUBiC).
CUBiC places Saint Lucia in a Z
factor of 0.75, which equates to azone 2 and 3 of the USA Uniform
Building Code (UBC). The level ofactivity is Saint Lucia is thus moderate but not to be ignored. A structure built using seismic building
codes is expected to fare better then
one that does not. One of CUBiC's
many recommendations are that thebuildings should be symmetrical.
This is a feature common among thevernacular architecture of Saint
Lucia and a practice that of late is
being exercised less and less.

CONCLUSIONSaint Lucia has been blessedwith infrequent fatal events ofearthquakes. However, it experiences frequent tremors of low magnitude. The last earthquake of significance was in 1990 when the island experienced a quake of magnitude 4.5. It caused the collapseof a bridge. Due to long intervals
between major earthquakes, developments spring up in areas which
are vulnerable against major earthquakes. Awareness of citizens
should be increased against such
infrequent but catastrophic events.
Design codes should be improved
to consider such adverse affects.
There are lessons to be learnt fromthe traditional construction practices and these lessons should be
utilized in present day constructionof the fast paced modern world.

Government Control: Land withhigh landslide risk should be declared to potential investors. Suchdeclarations would have resulting
consequences in the banking andinsurance sectors.

From Editor's Desk: This article
was originally submitted to INCEDE
Newsletter by Dr. French, Who is our
network member. Due to unavoidable
circumstances, it remained unpublished. We have decided to publish it
in ICUS/INCEDE Newsletter.

Second ICUS/INCEDE Open Lecture on January 24, 2002
On January 24, 2002, ICUS/
INCEDE is going to organize an
open lecture titled 'Towards the
Safe Cities in 21st Century' by inviting some prominent Japanese
researchers and decision makers as
speakers. The main speakers in thisevent will be Dr. T. Katayama, Director General, National ResearchInstitute for Earth Science and Disaster Prevention; Mr. T. Takahashi,

Director for Disaster Management,
Cabinet Office, Government of Japan (and Visiting Professor at ICUS/
INCEDE) and Prof. S. Murai, Professor Emeritus, University of Tokyo. The speakers will focus on various aspects of urban risk management in their presentations.
The Lecture will be held from13:00 - 17:30 at the Seminar Hall of

the Institute of Industrial Science,
University of Tokyo. This will be
the second Open Lecture organized
by ICUS/INCEDE. The series ofOpen Lectures are organized withthe aim at building a forum for sharing knowledge and information between experts and general public.
You are most welcome to participate in the second ICUS/INCEDE
Open Lecture.

ICUS/INCEDE Newsletter Vol. 1, No. 2

page 6

ICUS/INCEDE Workshop on Urban Safety Engineering in Thailand
ICUS/INCEDE organized aworkshop on 'Urban Safety Engineering 2001' at the Asian Instituteof Technology (AIT), Thailand
during September 21-22, 2001. The
workshop mainly focused on threeareas: 1) the tools: Remote Sensing, GIS, GPS, etc., 2) the objectof risk of urban structures, and 3)
the management and mitigation
policy of disaster. The major objectives of the workshop were: 1)
promoting better understanding between the researchers from prominent research institutes in Thailand
and ICUS/INCEDE in the areas ofurban safety engineering and environment, and 2) identifying possible areas for future collaborative
research. The future collaborative
research works are expected to emphasize on: a) development of theinspection method and enhancement of durability of urban structures; b) preparation of synthetic
hazard map and development of thereal-time monitoring technology;
and c) preparation of the effective
disaster-prevention manual.
The first day of the workshop
was designed as plenary meetingwith distinguished speakers fromthe University of Tokyo, AIT,
Chulalongkorn and Thammasat
Universities of Thailand. The
workshop was kicked off with twoProf. T. Uomto, ICUS/INCEDE Director, during his opening speech
opening speeches from Prof. Worsak
Kanok-Nukulchai, Dean of Schoolof Civil Engineering, AIT and Prof.
Taketo Uomoto, Director of ICUS/
INCEDE. It was followed by technical presentations. A total of 14
technical papers were presented by
the researchers from Japan and Thailand. The workshop was attended byabout 50 participants including the
researchers and students from AIT.
At the end of first day of the technical sessions, a technical visit was arranged for the participants to thelaboratories of the School of Civil
Engineering and Asian Center for
Research on Remote Sensing(ACRoRS) for demonstration on thetheir research facilities and ongoingprojects.

The second day was devoted fora close consultation on proposed
activities of ICUS/INCEDE forcollaboration with Researchers
from Thailand, which hopefully
can be extended to include a fullinternational network in future.
First, the participants introduced
the research topics of their own interests and it was followed by alengthy discussion to identify themost important research issues inurban safety engineering in Thailand where ICUS/INCEDE canparticipate as a collaborative organization and can support intransfer of knowledge and technology. The areas identified as the
focal areas for future collaboration
are grouped into three categories:

Participants pose for a group photo at the end of the workshop

ICUS/INCEDE Newsletter Vol. 1, No. 2

page 7
1) improvement of sustainability ofurban structures, 2) prediction, assessment and management of natural and artificial disasters, and 3)
information technologies and systems for urban safety.
Finally, a resolution was madeby the workshop participants where
it was agreed that continued cooperation between researchers andpractitioners in participated insti-

tutes be encouraged, and mechanisms for improved technology exchange and sharing be explored, andbased on the results of this workshop, opportunities for collaborative
research and information sharing
should be further explored, and potential funding sources for such collaborative research should be identified and contacted within Japan and
Thailand. The participants recognised the need to closely monitor thework identifying joint projects andshare information. To this end, it
was resolved that the next meeting of the research team may beheld in 2002.
A report of the proceedings of
the workshop is currently being
prepared at ICUS/INCEDE. Those
who are interested to receive a
copy of the report may contact us.
(By D. Dutta)

International Events participated by ICUS/INCEDE Staff
Prof. T. Uotomo, Director of
ICUS/INCEDE participated in two
international conferences: 1) International Conference on Fibre Reinforced Plastic for Reinforced
Concrete Structures (FRPRC-5)
which was held in Cambridge during July 15-20, 2001, and 2) Second International Conference on
Engineering Materials held in San

Jose, California, USA during August
16-21, 2001.
Prof. Y. Yasuoka participated in
the Eighth Asia-Pacific Regional
Space Agency Forum held during
July 23- 25, 2001 in Kuala Lumpur,
Malaysia. In this forum, he chaired
a session "Earth Observation - Integrated Monitoring System", andgave a special lecture "Integrated

Monitoring System for Environment and Disaster Managementwith Earth Observation Satellite".
Dr. K. Meguro participated inthe "Peru-Japan Joint Workshop on
Earthquake and Tsunami Disaster
Mitigation in the Asia and PacificRegion" held during July 19-20 inLima, Peru and carried out site investigation of Atico earthquake.

A HAPPY NEW YEAR 2002

Best Wishes for
A Happy New Year 2002
to all the Readers
from
ICUS/INCEDE Staff

ICUS/INCEDE Newsletter Vol. 1, No. 2

page 8
Editor’s Note
By the time this newsletter
reaches you, we will step into thedawn of 2002. I would like to takethis opportunity to express my best
wishes to all the readers for a happy
and prosperous new year.

members around the world. The
main article of this newsletter was
originally submitted for INCEDE
newsletter by a network member. We
hope to receive the contributions of
the network members to this newsletter as before.

With a decade long experienceof INCEDE in disaster mitigationengineering, ICUS/INCEDE expands the center activities to urban
safety issues. Together with the
expanded research areas, we arecontinuing many of the activities
initiated by INCEDE, one of thoseis the publication of this quarterly
newsletter. We also continue the
INCEDE networking with various

Many of us have the illusion thatonce the buildings and infrastructures are built, they will last long
without any maintenance. In reality,
urban structures are not safe and long
lasting without proper maintenance.
We have got the proofs in Japanthrough many recent incidents suchas, falling of concrete in tunnels, etc.
With the rapid urbanization, our cities are getting full of structures. We

have to find out the ways to maintain the safety of our urban environment. ICUS/INCEDE carriesout research on finding innovative
methods for urban safety. Recently,
we have organized a workshop on
Urban Safety Engineering in Thailand. Through this workshop, we
have identified many common areas of interest for future collaboration with the researchers from Thailand. We would like to work together to share our experienceswith the research communities
from other countries too. We encourage you to write your ideas tous. Let us work together for urban
safety.
(D. Dutta)

ICUS/INCEDE, 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-incede.iis.u-tokyo.ac.jp/

International Center for Urban Safety Engineering, ICUS/INCEDE
Institute of Industrial Science, The University of Tokyo
4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan

D

RS

IN

IT Y

OF

OF

TE

TO KY

O

I N S TIT U

US

TR

IA L

S C IE

N CE

THE

UN

IV

E

International Center for
Urban Safety Engineering

ICUS/INCEDE Newsletter Vol. 1, No. 2