Earthquakes - significant issues - David Alexander
Construction failure poses the greatest threat to life in earthquakes
Structural integrity : a building's physical adequacy for its intended purpose Failure : total or partial collapse, or the destruction or non-functionality of a building .
Seismic damage to buildings
is a function of:-
seismic energy expenditure:
duration of strong motion
distance from epicentre
(soft sediments amplify waves)
effect of construction type
regularity of building form
state of maintenance of building .
In the Tangshan (China) earthquake of July 1976 (magnitude 7.6), of 352 multi-storey buildings:
4 (1%) maintained their
177 (50%) collapsed completely
85 (24%) collapsed partially
86 (25%) were severely damaged
Knowledge must be gained of how to:-
buttress buildings temporarily
repair buildings permanently
design and construct
buildings antiseismically .
Antiseismic design utilizes:-
experience of a building's
hypotheses about a building's
design techniques to combat
weaknesses in buildings
induced by earthquakes .
The largest urban seismic risk is in Istanbul and Tehran Major earthquakes represent an enormous urban search-and-rescue (USAR) challenge
The international relief system is hugely expensive and inefficient $1,000,000 per life saved!
in the 20th century 46 lethal
earthquakes caused 128,000 deaths
a damaging quake once in 24-56 months
70% of the population lives in
municipalities classified seismic;
40% in 2,965 highly seismic ones
greatest risk is in the
22,000 historical town centres
35.3% of homes in earthquake zones
are anti-seismically constructed .
VICTIM UNINJURED INJURED HEALTHY INFECTED WORSENING OF CONDITION IMPROVEMENT OF CONDITION HEALTHY IMPROVEMENT OF CONDITION DISEASES INJURIES Public health measures Search and rescue Medical assistance Medical aid Mortuarial and funeral services WORSENING OF CONDITION DEATH DISASTER
No damage to buildings Damage to buildings Source: Linda Bourque, UCLA Injuries Emergency room injuries Hospital admissions
In the El Salvador earthquake of 1986 hospitals collapsed . In the El Salvador earthquake of 2001 hospitals collapsed . In the Bam, Iran, earthquake of 2003 hospitals collapsed . In the Italian Irpinia-Basilicata earthquake of 1980 hospitals collapsed . ....haven't we learnt anything at all?
"At Olive View Medical Center, two buildings collapsed in 1971, and three people died, including two patients on life-support systems that failed when auxiliary generators did not start. The third was an ambulance driver who was crushed by a falling wall. Olive View was an 888-bed hospital then. It had only been open a month when the quake hit. Because of extensive damage, the hospital was rebuilt, with attention to strengthening it against any future quake. But it was much smaller. Now it has a capacity of 377 patients." [Sylmar, California, history file]
Of the 58 fatalities caused by building damage, 50 occurred in hospitals. The worst damage to medical facilities occurred at the Veterans Administration Hospital in Sylmar where two large buildings collapsed. Even though the hospital site was right on the edge of the heavily urbanized San Fernando Valley, it took one hour and 22 minutes before a fire department helicopter happened to spot the collapses and send help. The reason for such a delay? The phones didn’t work, the hospital’s radio was in one of the collapsed buildings, and the first message orally delivered by a hospital staff member to a nearby government facility was confused with an already received report of damage to a different nearby hospital. [Reitherman 2004]
Seismic hazards to hospitals:-
loss of structural integrity
and building functionality
seismically-induced flooding ,
landsliding and subsidence
loss of trained personnel
loss of medical and surgical capacity
loss of supplies (including utilities)
and failure of supply chains
Unaccaptable performance Unaccaptable performance Unaccaptable performance Fully operational Operational Life safe Near collapse Collapse Rare 60%g Very rare 80%g Seismic design level Hospitals
beds ( expandable )
surgical and curative ( fixed or
diminished in the short term) .
ensuring continuity of
services and medical supplies
ability to cope with very
large surges in demand
protecting personnel and
their immediate families
protecting lifelines that enable the
injured to access medical care .
ensuring the structural integrity
of the medical facility
seismic integrity surveys
(structural and non-structural)
emergency planning (...testing,
revising, diffusing plans...)
estimate medical, surgical,
pharmaceutical and logistical needs
earthquake casualty estimation .
The three foci of medical emergency planning Health facility network emergency plan Other hospitals and clinics in the area External emergency plan Site of the disaster Internal emergency plan
Disaster in the medical centre Disaster in the system of medical centres Disaster in the external environment Co-ordinated EMS Disaster plans Disaster planning for the medical centre Disaster planning for the system of medical centres Disaster planning for the external environment
Disaster T1 T1 T2 T2 T2 T2 Helicopter links Telecommunications links Ambulance routes Emergency bus transportation Primary triage point Secondary triage points Pulmonary specialists Burns unit Emergency operations commander Coroner Next-of-kin Incident command post Incident commander Hospital I Hospital II Mortuary Secondary treatment centre Emergency operations centre Staging area
Now over to you!
1. A major earthquake has severely damaged a hospital which has a large Accident & Emergency department and is located in the heart of a metropolitan area. Describe how you would manage the situation. 2. A major earthquake has caused a row of tall apartment blocks to collapse. They were inhabited. Describe how you would manage the emergency response. 3. A major earthquake has left 15,000 people unable or unwilling to return to their homes. Describe how you would manage the shelter and structural survey problem.