A Brochure for Earthquake Disaster
As the Chiayi Rueili earthquake occurred on July 17, 1998, I remember at that
time I was in my office, which is on the 19-th story. Even though the earthquake
intensity was not very large at Taipei, I still could explicitly feel the shaking of the
building and was shocked by the shaking both physically and mentally. Immediately
following the earthquake, damages to house, hotel, school building and bridge were
reported. In addition, 5 people were killed. In the next few days, the rescue was
continued and it is very concerned about whether it is an indication for a severe
earthquake after a lot of aftershocks.
Similar to the typhoon or ocean wave, the earthquake is a part of the natural
activity. However, it is a pity that up to now no one around the world can reliably
predict the occurrence of an earthquake with the right time, right location and right
magnitude as those predicted for a typhoon. Consequently, the earthquake still gives a
great threat for the people resided in Taiwan, such as those resided in Tokyo and
Kobe, Japan, as well as in Los Angeles and San Francisco, U.S.A. since all these
areas are located on the collision boundary of the Eurasian plate.
Although earthquake is unpredictable the damage to life and property can still be
minimized based on the technology developed in Taiwan if the earthquake prevention
is well prepared and the emergency response is appropriately taken. National Science
Council of the Republic of China continues its full support for the research on
seismology and earthquake engineering. In addition, the National Center for Research
on Earthquake Engineering (NCREE) was founded a few years ago. A large structural
laboratory was constructed for the improvement of earthquake resistant design and
the development of new technology for seismic isolation.
The content of this brochure is the research results regarding to the earthquake
itself and its damage prevention from the specialists in the Academia Sinica and in
the ministry of economic and transportation. Hopefully, this brochure can effectively
alleviate the earthquake damage to life and property after reading of it since one can
well prepared for earthquake disaster after recognizing the possible damages caused
by an earthquake.
Knowledge and action are the best prevention when you face an earthquake. Best
2. Organization and Strategy for Earthquake Disaster Prevention and Rescue
l Organization for Catastrophic Disaster Prevention and Rescue
l Community Organization for Disaster Prevention and Rescue
l Guidelines to Reduce Earthquake Damage for Individuals
3. Failure Modes of Buildings under Seismic Loading
Appendix 1. Seismic Hazard in Taiwan Area
On July 17, 1998, an earthquake occurred at the Chiayi County with a magnitude
of 6.0 on the Richter scale. Since this earthquake is the only earthquake that caused a
severe damage and even the death of people for the recent 30 more years in the area
of Chiayi-Tainan in Taiwan it attracts much attention. In fact, the seismic activity in
this area is widely discussed after a long period of inactivity. Because this event is a
very shallow earthquake the ground shaking near the epicenter is tremendous and
thus the damage to buildings, bridges and roads is inevitable.
Since the tectonic movement continues the seismic activity in Taiwan area will
never be stopped. In fact, an earthquake will occur after the energy is accumulated to
be large enough. Even though the capability to earthquake resistance of a structure is
significantly improved an earthquake with a magnitude over 7.0 might still lead to a
catastrophic disaster and the damage may be more severe than that caused by any of
the pass earthquake events.
This brochure is proposed to provide the general public with the awareness of an
earthquake and the simple guidelines to respond with the earthquake disaster. Hence,
if one has the earthquake preparedness in advance, appropriately responds during the
earthquake and takes the right actions after the event the earthquake damage then can
be effectively minimized.
2. Organization and Strategy for Earthquake Disaster
Prevention and Rescue
(a) Organization for Catastrophic Disaster Prevention and Rescue
In order to mitigate the threat from an earthquake, all levels of the government in
the world will generally raises the importance of damage prevention before the quake,
emergency response and rescue during the quake and the recovery after the quake. As
a result, the organization for disaster prevention and rescue is founded. In Taiwan,
these organizations were set up from the central to local governments since 1994. In
addition, the meeting is regularly held by each level of government to propose the
plans for disaster prevention and rescue. These plans can be considered as the
guidelines for the disaster prevention before an earthquake, for the emergency
response and rescue in an earthquake and for the recovery after an earthquake.
As a catastrophic disaster occurs, the procedure to damage prevention and rescue
will be preceded by the government as follows:
(a-1) The government infrastructure for
disaster prevention and rescue, such
as the fire fighting department and
the police department, should
collect the information about the
emergency faced and go to the
(a-2) Report the damage to the authorized government agencies. Then, they will
organize a team to respond with rescue and
recovery operations according to the plan for
(a-3) The authorized government agency should
report to the responsibilities of the district
administrator to establish the “Emergency Response
Center” for the emergency management and rescue.
(a-4) If the government infrastructure cannot handle the disaster rescue or
recovery it should make a request for assistance from the higher level of
government. The level of government to assist the emergency response and
rescue is dependent upon the actual need of
(b) Community Organization for Disaster Prevention and Rescue
Disaster prevention and rescue involves every one, family and community. In
addition, community organizations for disaster prevention and rescue are the basis of
the national organization for disaster prevention and rescue. They can reduce the
causes to disasters in the usual time and in a disaster they will go to rescue first. In
fact, in case of disaster the elected district administrators, such as town supervisors or
village executives, should assemble their members to involve the immediate rescue.
This may include emergency medical services, fire fighting, shelter, food, water and
essential services. A well-coordinated emergency response to an earthquake is likely
to save many lives and prevent earthquake-induced hazards escalating the magnitude
of the disaster.
(b-1) Development of the Community Organizations:
It is necessary to set up a community organization for disaster prevention and
rescue based on the conditions and needs of the specific district region. The
following skeleton is used to Supervisor
illustrate a possible
food supply Casualty Savage information report
shelter guide fire fighting
(b-2) Emergency Preparedness:
Community organizations can promote participation in emergency
preparedness activities and help organize practice drills and exercises to raise
awareness and ensure that everyone knows what to do. In addition, a
community disaster plan can also be drawn up, involving fire-fighting, search
and rescue, first aid, making contact with
authorities, supervision of food, water and
(b-3) Emergency Response:
Pre-earthquake emergency planning is one of the best ways to ensure that the
earthquake disaster can be handled effectively. In fact, as a disaster occurs,
using this plan with the usual
practice drills and exercises for
emergency response and rescue.
(b-4) Recovering from Earthquakes
Fit in with the government to gather data on the extent of damage and its
distribution in the community. In addition, help each other to recover from
If the earthquake causes people injured or a great loss, make a request for
assistance from the local government or call 119 for help.
3. Guidelines to Reduce Earthquake Damage for
(a) Before the Earthquake
(a-1) At Home
(a-1-1) Reinforcing shelving, fixing tall
furniture to the wall and keeping
items low and safe will make your
living environment a safer place.
(a-1-2) Recognizing the shelters and their
routes both at home and nearby.
(a-1-3) Recognizing the place of switch for
gas and electricity and how to turn off.
(a-1-4) Preparing an emergency box
and fire extinguishers. Let all
the family members know
where they located and how to
(a-1-5) In case of any problem in the
building, ask licensed engineers
or agencies to check and retrofit
(a-1-6) Check the equipments for
fire fighting and exercise the plan
for disaster prevention and rescue
regularly if you are living in a
(a-2) In the Public Place
(a-2-1) Propose an emergency plan and
assign the staffs or servers to take in charge
of the disaster prevention and emergency
(a-2-2) Check the equipments for
fire fighting regularly.
(a-2-3) Exercise the disaster
(a-2-4) Check the billboard and the
shelter from the sun or any other
potentially dislodged item
(b) During the Earthquake
(b-1-1) Turn off gas, electricity and
(b-1-2) Using an appropriate exit to
keep away from any
congestion in a public place.
(b-1-3) Open the door in order to avoid
that the door is jammed by the large
deformation in an earthquake.
(b-1-4) Stay away from the glass window
and find a safe shelter.
or lie down beside or underneath a
table or bed to protect against
possible objects falling from
(b-1-6) Keep calm and do not rush out in
(b-1-7) In case of fire put it out right away.
(b-1-8) Do not use the elevators but use
(b-2-1) If you are driving a car or
riding a bike do not stop
immediately. In stead, drive the
car or ride the bike to the
roadside and then find a shelter.
(b-2-2) If you are walking
in the street, run
into an open space
or the pedestrian
(b-2-3) Keep away from the gas
station, glass curtain wall, vending
machine, electric pole and
construction site, etc.
(b-2-4) Look out for any possible
objects falling from
above and put your arms
on your head.
(b-2-5) If you are on a bus or a train,
do not panic and jump outside.
Stay in the bus or train
temporarily and put your arms or
a bag on your head.
(b-2-6) If you are in a suburb, stay
away from the hill, riverside
and seaside and find an open
space for shelter.
(b-2-7) If you are on a
viaduct or an
walk away calmly and
(c) After the Earthquake
(c-1) Help each other for the disaster
rescue. Have a look at the other buildings
nearby. Their occupants may need your
(c-2) If electric power is recovered after the
power shutdown, do not use any electric
devices right away but check first whether
there is a leak of gas to keep away from any
explosion or fire.
(c-3) Listening to the radio or watching TV
any time and escaping from any rumor.
(c-4) Do not use the
telephone unless somebody
has been injured or a
building is damaged or
burning. The emergency
services may need all lines
for the rescue.
(c-5) Inspect the house for cracks. If
beams or columns are damaged leave
the house as soon as possible and ask a
civil agency to inspect and restore.
(c-6) If the gas pipeline is damaged or
there is a smell of gas, do not use any
gas or electric devices. Open the doors
and leave the house immediately. In
addition, report to the authority.
3. Failure Modes of Buildings under Seismic Loading
The habitation is always closely related to the human beings. Ancient people
resided in caves to shelter from the wind and rain. Following the progress in the
civilization of human beings, the construction materials for buildings are gradually
improved in the order of timber, rock, brick, reinforced concrete and steel. All the
buildings are located on the ground or even fixed into the ground. Therefore, when a
building is excited under an earthquake, its base tends to move with the ground where
it is supported. Taiwan area is in the time of high potential of the occurrences of
earthquakes. Furthermore, it can be expected that a lot of structures will be destroyed
to a different degree of damage if a strong earthquake occurs at the present time.
Some will be totally collapsed and some may be damaged and need to be retrofitted.
However, each structure must be well reevaluated by the engineers. The following
figures or photos are used to illustrate the general failure modes of buildings under
Brittle Failure at the End of a Column
Since a reinforced concrete column will in
general be subjected to a maximum moment at
its ends adequate stirrup reinforcement is
needed at the column ends. If the stirrup
reinforcement is too short or widely spaced
brittle failure may occur at the column end due
to the inadequate confinement in longitudinal
bar and concrete. If this occurs in several
columns of the same story this building may be
collapsed at any story.
Failure of the Short-Column Type
In general, the design of a column is based
on its net height. However, the window above half-height in-filled shortens the
effective length of the column. This may cause the shear force to be greater than the
shear capacity possessed by the column and finally might result in a diagonal shear
crack in the column. This is the so-called “short-column” type damage.
Punching Shear Failure
When two-way slabs are supported
directly by columns, such as in flat slabs and
flat plates, or when they carry concentrated
loads, such as in footings, punching shear near
the columns is of critical importance. For the
failure of punching shear, the potential
diagonal crack follows the surface of a
truncated cone or pyramid around the column.
Unfixed Heavy Objects in the Top Story
During an earthquake, the top story
response is generally greater than the low story
response and then it will experience a larger
seismic force. As a result, if any heavy object in
the top story is not fixed tightly it may fails or
falls down in an earthquake.
Interaction of Axial Load and Side-Sway
An axially loaded column accompanying with a
side-sway will cause the secondary moment for the
column. Thus, the increase of the axial loading may
result in the buckling or yielding of the column and
eventually the collapse of a whole story.
Individual building need to be provided with
adequate separation, to prevent damage caused by
pounding when deform in earthquake, which has been a
serious cause of damage to multistory structures, even of
collapse, in recent earthquakes. The minimum separation
gap depends on the height of building and on the
flexibility of the building. The gap between buildings
should exceed the maximum drift of each story with an
Failure of Accessory and Nonstructural Element
Accessory of a building such as the water
tank, TV and elevator and the nonstructural
element such as the curtain wall, interior
partition and staircase may be destroyed by the
large deformation due to a severe earthquake.
Especially, the break of elevator and collapse of
the interior partition may damage to life.
Failure of the Pre-damaged Structural Element
The capability to earthquake resistance of a
structural element may be reduced due to the
implementation of a nonstructural element. For instance,
a drainpipe is usually embedded in the column. Thus,
the effective area for the column to resist the axial force
is reduced. Furthermore, if there is a leak in the
drainpipe the concrete and steel will be corroded with
the time passing. Consequently, this structural element
will be damaged prior to the other structural elements
and may lead to collapse of the whole building.
Sloping ground or rock masses, which are
stable under normal loading, can lose their
stability during an earthquake causing effects
from a slow progressive creeping of the
ground to dramatic landslide or rock fall.
Whether sudden or slow, such slope failures
are liable to cause complete destruction of any
building founded on them or in the path of the
slide. Landslide and later spreads can also
cause extensive property damage.
Fault Rupture Failure
Large permanent ground deformations often
occur at the surface associated with fault
ruptures in earthquake. Vertical and horizontal
displacements have occurred across fault breaks;
where this relative movement occurs under a
building, a bridge or any structure catastrophic
damage can result.
Foundation Failure due to Soil Liquefaction
Earthquake-induced soil liquefaction has been the cause of catastrophic damage
in a number of earthquakes. Certain types of soils, when they are saturated with water
and then suddenly shacked by an
earthquake, completely lose all shear
strength, and flow like a liquid. The
support to the foundations of buildings or
bridges built on such soils then disappears,
and they can plunge into the ground, or be
carried sideway bodily on unliquefied
masses of soil.
Appendix: Seismic Hazard in Taiwan Area
1. Causes of Earthquakes
l Distribution of Earthquakes
The distribution of earthquakes in the world is well recognized after the study of
several decades. It is concluded that earthquake occurrences are not distributed
uniformly over the surface of the earth; instead they tend to be concentrated
along well-defined lines, which are known to be associated with the boundaries
of plates of the earth’s crust. There are three principal world zones or belts of
earthquake activity. They are the Circum-Pacific seismic zone, the Eurasian
seismic zone and the Mid-oceanic ridge. It is worth noting that some large and
highly destructive earthquakes do occur in continental zones but not in the three
principal world zones mentioned above. In fact, there are the so-called intra-plate
earthquakes, such as the 1812 New Madrid earthquake in Missouri, U.S.A. and
the 1976 Tangshan earthquake in China.
The island of Taiwan is located at the Circum-
Pacific seismic zone and thus seismicity is
extremely active in this country. Based on the Earthquake Belt
distribution of the recorded earthquakes,
Taiwan can be roughly divided into three Earthquake
seismic zones. They are the northeastern
seismic zone, the eastern seismic zone and the
western seismic zone as shown in the figure. Eastern
Most earthquakes occurred in the eastern and Earthquake with Belt
western seismic zones are shallow earthquakes
while shallow-, medium- and deep-focus
earthquakes are common in the northeastern
seismic zone. Earthquake with Surface Rupture in Taiwan
l Active Fault
An earthquake may be induced by many causes, such as volcanic eruptions, the
collapse of underground mine-workings, man-made explosions and the fault
ruptures. However, the fault rupture causes the most earthquakes and thus is of
importance. In fact, about 90% earthquakes are tectonic earthquakes in the world.
An active fault implies its recurrent movement for a specific period of time.
However, a given time period may not be satisfied for all the users of different
purposes under different tectonic settings. Recently, Central Geological Survey
has collected all the active fault data in Taiwan area and gives the definition for
an active fault. In fact, it will be considered as an active fault if there is recurrent
movement in the late Quaternary period. Furthermore, active faults are classified
into two categories based on the identified period of last movement. The first
category of active faults includes those (1) activated in the Holocene, (2) offset
(creep) the man-made structures, (3) relate to recent large earthquakes, (4) offset
the recent alluvium and (5) show the creeping phenomena as verified by the
present geodetic method. On the other hand, the second category of active faults
is those (1) activated within the last 100,000 years or (2) offset the terrace
deposits or tableland deposits. In addition, some
active faults are not classified into the two
categories due to the lack of geologic evidences
and are considered as suspect active faults. The
distribution of active faults, whose fault trace is
greater than 5 km in Taiwan area, is shown in
figure with a scale of 1:500,000 geological map.
There are 51 active faults in total, 9 are in the
first category, 15 are in the second category and
the rest 27 faults are the suspect active faults. In Taiwan
2. Possible Earthquake Damages
The movement of tectonic plates Landslide Surface Rupture
may lead to the fault rupture and then
results in an earthquake. When the
rupture occurs, the release of strain
adjacent to the crack surface will be
accompanied by a sudden relative
displacement of the two sides. Thus, a Landslide Bridge Broken
displacement wave is initiated by this
rupture and will be propagated radially
from the source. Consequently, the
severe ground shaking introduced by
Tsunamis Building Collapsed
the earthquake wave may cause
damage to the structure, life and
property. In general, earthquake
damages can be simply classified into
two types, which are the direct and
A fault rupture may lead to tsunamis, landslide, large ground deformation, soil
liquefaction and then the damage to structures. All these can be considered as the
direct damage. On the other hand, the indirect damage implies secondary disasters
triggered by the earthquake or the earthquake-induced accidents. Flooding following
earthquakes may result from the failures of reservoirs or embankments. The failure of
pipeline may lead to a leak of gas or a fire arising from the short circuit. In addition,
the overturning of building contents and equipment may also impair life. It should be
mentioned that more fatalities are caused by the failure of nonstructural elements or
by earthquake-induced accidents than are caused by the collapse of buildings.
When the earthquake occurs, it might cause… .
Leak of poison gas in factory Catastrophic damage
The difficulty to resoue
The difficulty for fire fighting
3. Earthquake Disasters in Taiwan
The history of seismic activity in Taiwan can be dated back to the seventeenth
century. Prior to 1897, the historical records of earthquakes are made up of local
governmental documents and personal diaries and accounts. In 1897, seismographs
were first installed in Taiwan. After the use of seismographic instruments, there were
125 destructive earthquakes between 1898 and 1998. The greatest earthquake is the
one occurred on June 5, 1920 at Hualien. The magnitude of this earthquake is as large
as 8.0. According to the past earthquake data, the most active seismic zone in Taiwan
is near Hualien and Ilan region. Meanwhile, most destructive earthquakes occurred in
the western region of Taiwan are in the area of Hsinchu, Taichung, Chiayi and Tainan.
Among the 125 destructive earthquakes, 30 events occurred in the western region.
Even though the occurrence rate in the western region is lower than that of the eastern
region, the earthquake disasters caused in this region are more severe than those of
the eastern region. Hence, this needed to be greatly considered in construction.
Observing the earthquake events
recorded by the seismographic
instruments from 1898 to 1998, the
magnitude, epicenter, tectonics and
building type of the most severe 10
events are different. Thus, each caused a
different degree of damage. In general, if
the epicenter is in mountainous terrain
such as the 1998 Ruilei earthquake,
landslide is the major geologic damage.
However, in plains the major geologic
damages are the fault rupture, surface
break, quick sand, and soil liquefaction.
What kind of geologic environment is apt
The Epicenter Map of the most severe Earthquakes
to have above geologic damages? In in Taiwan,1898-1998
plains, the geologic damages such as the offset, surface break and quick sand mainly
caused by the fault rupture. Liquefaction is most likely to occur in loose cohesionless
soils, such as fine sand or silts; these are most commonly found in sea or river
deposited sediments. These geologic damages may lead to the collapse of structures
and the destruction of pipelines. Landslides may occur at the steep slopes in
mountainous terrain. Thus, it is very important to protect the building and road from
rockfalls and mudflows by using a retaining structure.