TASK8-Engineering Disasters
Transcript of TASK8-Engineering Disasters
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 1/11
0
ENGINEERING DISASTERS
ADVANCED CIVIL AND ENVIRONMENT ENGINEERING
Taufiq (10-8705-601-88)
Master Degree Course
Faculty of Civil and Environment Engineering
YAMAGUCHI UNIVERSITY
2010
I. BHOPAL DIS A STER
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 2/11
1
The Bhopal disaster was an industrial catastrophe that took place at a pesticide plant owned and
operated by Union Carbide India Limited (UCIL) in Bhopal, Madhya Pradesh - India on December 3rd,
1984. Around 12 a.m, the plant released Methyl IsoCyanate (MIC) gas and other toxins, resulting in the
exposure of morethan 520.000 people.
During the night of December 2²3, 1984, large amounts of water entered tank 610, containing 42
tonnes of methyl isocyanate (MIC). The resulting exothermic reaction increased the temperature inside
the tank to over 200°C (392 °F), raising the pressure to a level the tank was not designed to withstand.
This forced the emergency venting of pressure from the MIC holding tank, releasing a large volume of
toxic gases into the atmosphere. The reaction sped up because of the presence of iron in corroding
non-stainless steel pipelines. A mixture of poisonous gases flooded the city of Bhopal, causing great
panic as people woke up with a burning sensation in their lungs. Apart from MIC, the gas cloud
contained poisonous gases such as phosgene, hydrogen cyanide, carbon monoxide, hydrogen chloride,
oxides of nitrogen, MonoMethyl Amine (MMA) and carbon dioxide, either produced in the storage
tank or in the atmosphere. Thousands of people died immediately from the effects of the gas and
many were trampled in the panic.
Picture 1. Union Carbide MIC Plant after Tragedy (Source: Wikipedia)
Health Eff ects
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 3/11
2
The initial effects of exposure were coughing, vomiting, severe eye irritation and a feeling of
suffocation.
The acute symptoms were burning in the respiratory tract and eyes, blepharospasm,
breathlessness, stomach pains and vomiting.
The causes of deaths were choking, reflexogenic circulatory collapse and pulmonary oedema.
Findings during autopsies revealed changes not only in the lungs but also cerebral oedema, tubular
necrosis of the kidneys, fatty degeneration of the liver and necrotizing enteritis.
The mortality rate increased by up to 300% and neonatal mortality rate by 200 %.
Birth defects among children born to affected women.
There were several other effects such as respiratory difficulties, immune and neurological
disorders, cardiac failure secondary to lung injury and female reproductive difficulties.
The number of people affected is more than 520.000. The Tragedy killed 4.000 immediately, 10.000
within 72 hours and more than 25.000 have died since then. All leaves yellowed and fell off within 72
hours and also water got contaminated.
Picture 2. Victims of Bhopal Gas Tragedy
What caused the disaster
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 4/11
3
Factors leading to this huge gas leak include:
The use of hazardous chemicals (MIC) just for the sake of cost saving
Storing these chemicals in large tanks instead of over 200 steel drums.
Possible corroding material in pipelines
Poor maintenance after the plant ceased production in the early 1980s
Poor training of factory staff
Failure of several safety systems (due to poor maintenance and regulations)
Safety systems being switched off to save money - including the MIC tank refrigeration system
which alone would have prevented the disaster
Negligence of safety standards by UCIL, even after several warnings by employee unions
The problem was then made worse by the plant's location near a densely populated area,
non-existent catastrophe plans and shortcomings in health care and socioeconomic rehabilitation
A f termath
The Central and State Governments tried to provide medical facilities, food and water supplies to
affected people. The effort was far inadequate compare to the real requirement. Foods were distributed
only for short period. Government was unable to provide victims proper rehabilitation. Widows were
granted a mere Rs. 200 per month as pension. After a long trialed case against UCC, a dismal sum of
$470 million (insurance sum plus interest) was paid by UCC in full and final settlement of its civil and
criminal liabilities, that too in year 1999. In 2001 Dow Chemical Company (DCC) acquired UCC. DCC
believes that all the liabilities of UCC have been fulfilled and now there is no responsibility left for
DCC. Lack of political willpower has led to a stalemate on the issue of cleaning up the plant and its
environs of hundreds of tonnes of toxic waste, which has been left untouched. Environmentalists have
warned that the waste is a potential minefield in the heart of the city, and the resulting contamination
may lead to decades of slow poisoning, and diseases affecting the nervous system, liver and kidneys in
humans. According to activists, there are studies showing that the rates of cancer and other ailments
are high in the region. Activists have demanded that DCC clean up this toxic waste, and have pressed
the government of India to demand more money from DCC.
II. TETON DAM FA ILURE
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 5/11
4
Figure 3 The details f igure of Teton Da¡ construction
De¢
£
gn and Con¢
¤
¥ uc¤
£
on
The Teton Da¦
was located on the Teton Ri v er, three miles northeast of §
e w dale - Idaho. It was
esta ̈
lished to pro v ide recreation, f lood control, po w er generation, and irrig ation f or o v er 40,000
hectares (100,000 acres ) of farmland. The Off ice of Design and Construction, U.S. Bureau of
Reclamation ( USBR ), at the Den v er Federal Center, designed the dam and the construction contract
was awarded to the team of Morrison-Knudsen-Kie w it in December of 1971.
The preparations f or this dam project had been under wa© f or many years. The f irst acti v e site
in v estig ation in the area occurred in 1932 ( Teton Dam Failure @ 2002). Betw een 1946 and 1961,
eight alternate sites w ithin about 16 k m of the selected site w ere in v estig ated. Betw een 1961 and 1970,
approximately 100 borings w ere tak en at the site (Independent Panel, 1976).
The design of the f oundation consisted of f our basic elements: 1). 21 meter deep, steep-sided k ey
trenches on the abutments abo v e the ele vation of 1,550 meters, 2). a cutoff trench to rock belo w the
ele vation of 1,550 meters; 3). a continuous grout curtain along the entire f oundation; and 4). the
excavation of rock under the abutments (Independent Panel, 1976). These elements f or the f oundation
w ere important because the types of rock located in this area, basalt and rhyolite, are not generally
considered acceptable f or structural f oundations.
The embank ment itself consisted of f i v e main zones. Zone 1 was the imper v ious center core, w hich
f ormed the water barrier of the dam. Zone 2 o v erlaid Zone 1 and extended do w nstream to pro v ide a
layer to control seepage through the f oundation. Zone 3 was do w nstream and its main f unction was to
pro v ide structural stability. Zone 4 consisted of the storage areas do w nstream f rom the controlstructure and the temporary enclosures built to permit the w ork to be done. Finally, Zone 5 was the
rockf ill in the outer parts of the embank ment (Independent Panel, 1976).
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 6/11
5
Construction of the dam beg an in February 1972 and the embank ment w ould hav e a maximum height
of 93 meters abo v e the ri v erbed and w ould f orm a reser v oir of 356 million cubic meters (288,000
acre-f eet) w hen f illed to the top. The dam was closed and beg an storing water on October 3, 1975, but
the ri v er outlet w ork s tunnel and the auxiliary outlet w ork s tunnel w ere not opened (
rthur, 1977).
Due to these sections being incomplete, the water was rising at a rate of about 1 meter (3 f eet) per day,
w hich was higher than the predetermined goal rate of 0.3 to 0.6 meters (1 to 2 f eet) per day f or the f irst
year, as set by the U.S. Bureau of Reclamation. Ho w e v er, the increased rate was expected, due to the
tunnels being incomplete, and considered acceptable by the Bureau of Reclamation as long as seepage
and the water table do w nstream of the dam w ere measured more f requently (Independent Panel,
1976).
The Failu e
On June 3, 1976 se v eral small seepages w ere noticed in the north abutment wall. This led to more
f requent inspections of the dam. It was no w to be inspected daily, and readings w ere to be tak en tw ice
w eek ly instead of once a w eek . On June 4, 1976 w etness was noticed in the right abutment and small
springs w ere beginning to appear (Independent Panel, 1976).
On June 5, 1976 the f irst major leak was noticed betw een 7:30 and 8:00 a.m. The leak was f lo w ing at
about 500 to 800 liters per second (20
to 30 cf s ) f rom rock in the right
abutment. By 9:00 a.m. the f lo w had
increased to 1,100 to 1,400 liters per
second (40 to 50 cf s ) and seepage hadbeen obser v ed about 40 meters (130
f eet) belo w the crest of the dam (
rthur,
1977).
At 11:00 a.m. a w hirlpool was obser v ed in the reser v oir directly upstream f rom the dam and f our
bulldozers w ere sent to try to push riprap
into the sink hole near the dam crest
(Independent Panel, 1976). T w o of the
bulldozers w ere s wallo w ed up by the
rapidly expanding hole, and the operators
w ere pulled to saf ety by ropes tied
around their waists ( Teton Dam Flood @
2002).
Picture 4. The f irst major leak in Teton Dam construction
Picture 5. Turbid nature of outf lo w along the abutment
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 7/11
6
The hole continues to enlarge and rise to ward the crest of the right abutment. This is happen about
11.50 am. Then, dam crest beginning to breach at 11.55 am and maximum f lood discharge emanating
f rom g ap in dam`s right abutment, just after noon on June 5th, 1976.
Inve
igating Panel and R e ults
Follo w ing the failure, the Go v ernor of Idaho and the Secretary of the Interior selected an independent
panel to re v ie w the cause of the failure. This independent panel was made up of prominent ci v il and
geotechnical engineers including W allace L. Chad w ick , a f ormer president of the ASC
, and eminent
geotechnical engineers R alph B. Peck , H. Bolton Seed, and Arthur Casagrande. The panel beg an w ork almost immediately and issued its report in December, 1976 (Independent Panel, 1976).
The panel considered all possible causes of failure and tried to establish the sequence of e v ents leading
to the failure. During the in v estig ation, conditions fav oring erosion and piping w ere e valuated. Le v y
and Sal vadori (1992) def ine piping as ´the de v elopment of tubular leak -causing cav ities.µ
One of the f irst possible mechanisms considered was increased settling of the structure under the
w eight of the structure and the water, w hich w ould hav e led to crack ing. It was determined that this
did not contribute to the failure, because the tunnel belo w the spill way w ould also hav e been crack ed.
Furthermore, earthen dams are relati v ely f lexible and tolerant of diff erential settlements. The failure
hypotheses eliminated included seismic acti v ity, reser v oir leakage, and seepage around the end of the
grout curtain, as w ell as diff erential settlement.
Condition fav orable f or erosion and piping existed in Zone 1, w here the primary materials w ere highly
erodible silts. Where v er this material was subject to f lo w ing water it could be attack ed and washed
away. This contact could hav e occurred in three diff erent possible ways. First, seepage through the
Picture 6. Dam crest beginning to breach
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 8/11
7
material could have caused backward erosion. This was determined not to play a major role in the
failure since this process occurs very slowly. Second, erosion by direct contact could have occurred
where water was in contact with open joints and thirdly, where there was direct contact through cracks
in the fill itself. It was determined that these last two were possible and were probably occurring
simultaneously (Independent Panel, 1976).
The key trench contained a grout cap overlying a grout curtain that was intended to stop the flow, but
the investigation found openings and windows in the grout curtain near the failure section. The review
panel also found that the construction of the grout curtain differed from the original design. The
intended grouting procedure was to first grout the row of holes downstream, then grout the row of
holes upstream, and then grout the center row of holes. This procedure was not followed during
construction and the closure between the two outer rows, the center row of grout, was not made. Also,
the spacing between the holes was not as specified and gaps were more likely to be present
(Independent Panel, 1976). However, there is no way to determine if that had an impact on the erosion.
Another impact on the erosion was that the topography near the key trench showed that the
foundation was probably poorly compacted, which meant more rapid erosion could occur (Arthur,
1977).
Another cause of failure investigated was hydraulic fracturing near the leaks in the dam. Hydraulic
fracturing causes cracking when the sum of the normal and tensile stresses exceeds the porewater
pressure. It was determined that due to the cracks that had already existed, the pressure beneath the
key trench was less than full reservoir pressure. In other words, due to the fact that the grout curtain
was not fully effective, the failure was probably not due to hydraulic fracturing. However, hydraulic
fracturing may have been a factor in the initial breaching of the key trench fill (Independent Panel,
1976).
Another factor was the poor compaction of the aeolian silt fill material. It was compacted at less than
the optimum moisture content. The ´material, as compacted in the dam, permitted continuous erosion
channels (pipes) to be formed in the core without any evidence of their existence becoming visibleµ
(Independent Panel, 1976).
III.
Lessons Learned
Bhopal Disaster
These days we hear a lot about growing economy, spreading businesses, surging profits, expanding
industries, shrinking distances, and improving life styles. But what about social responsibilities,
humanity, duties towards environment. What about the basic right of very human being, which is to
live, whether he is rich or poor. The focus is on earning profits, not earning pleasure or happiness. The
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 9/11
8
aim is to earn status not respect. The whole tragedy happened because of the profit oriented outlook
of the company and ignorance of safety standards. The cost saving approach costed thousands of lives.
And this outlook has not changed even today rather intensified. Every now and then we hear about
violation of human rights, child labor etc. Who is responsible for this one, certainly is the society. Our
criterion for measurement of success is money not happiness. Everyone follows the herd mentality
even without where they are heading to, where the society is leading to, what are the implications of
industrial and business activities. This Tragedy is still in the memory of public because of its huge toll.
But society does not remember those numerous accidents and ill-effects of industrialization that
happen daily at small scale. The atmosphere is getting severely polluted; the water of rivers is no more
drinkable. Every now or then we hear about a new disease. The government compensation can·t bring
life for a dead. Money can·t buy happiness. Think about our responsibilities, our duties towards next
generation. It is high time to act for the betterment of planet earth.
Teton Dam Failure
The lessons learned from this case may be divided into two categories. In addition to the technical
aspects of the failure, professional and procedural factors also influenced the course of events. The
lessons learned also have implications for engineering education.
Technical As pects
The design of Teton Dam did not provide for downstream defense against cracking or leakage,
and did not ensure sealing of the upper part of the rock under the grout cap. The dam and
foundation were not instrumented sufficiently to warn of changing conditions.
Prof essional/Procedural As pects
At the first sign of a problem the people at the dam site informed the Bureau of Reclamation. The
Bureau did not immediately inform the public due to fear of panic and there were initially no signs
of imminent danger, but the public was warned about 45 minutes before the collapse (Arthur,
1977). It was determined that the people involved acted responsibly and were not punished for
their involvement.
Educational As pects
This case demonstrates the importance of engineering geology and geotechnical engineering for
civil engineering students. Engineering geology is important for evaluation of the suitability of
foundation and borrow or fill materials. In the design and construction of earth dams, it is
necessary to select proper materials that are sufficiently resistant to piping and to ensure that they
are compacted to the proper density. The design should incorporated adequate defense against
cracking and leakage. Finally, dams must have sufficient instrumentation to provide early warning
of piping and impending failure
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 10/11
9
IV. O pinion as a Gov ernment Em ployee
A disaster is the tragedy of a natural or human made hazard (situation which poses a threat to life,
health, property, or environment) that negatively affects society or environment. From the example of
disasters above, they can be defined as human-made disaster which are caused by human action,
negligence, or involving the failure of a system. Bhopal tragedy and Teton Dam failure are
technological disasters which are the results of failure technology that created as the consequence of
inappropriately managed risk.
No country can afford to ignore the lessons of Bhopal Tragedy and Teton Dam failure. Government
must concern for the devastating and increasing impact of natural and man-made disasters on human
lives, infrastructure and economies. Government at the national, regional dan international levels
should have an action to strengthen disaster management through increased capacity for disaster
preparedness, early warning systems, risk mitigation and post disaster recovery and reconstruction.
Though it may not be feasible to control nature and to stop the development of natural phenomena
but the efforts be made to avoid disasters and alleviate their effects on human lives, infrastructure and
property.
However, it is possible to reduce the impact of disaster by adopting suitable disaster mitigation
strategies. The disaster mitigation works that published by the government is a systemic work which
involves with different regions, different professions and different scientific fields, and has become an
important measure for human, society and nature sustainable development.
R ef erences:
- Arthur, H.G. (1977). ´Teton Dam Failureµ. The Evaluation of Dam Safety: Engineering Foundation
Conference Proceedings, ASCE, New York, New York, 61-71
- Independent Panel to Review Cause of Teton Dam Failure (1976). Report to the U.S. Department of the Interior
and State of Idaho on Failure of Teton Dam . Idaho Falls, Idaho. December 1976
- Macauley, D. (2000). Building Big, Houghton Mifflin Company, New York, New York.
- ´Teton Dam Disaster.µ Hearings Before a Subcommittee on Government Operations House of
Representatives, 94 th Congress, Second Session, August, 5, 6, and 31, 1976
- Levy, Matthys, and Salvadori, Mario (1992). W hy Buildings Fall Down . W. W. Norton & Company, New York,
N. Y.
- U.S. Bureau of Reclamation, Pacific Northwest Region, (1983) Teton Basic Project, Lower Teton Division; Idaho;
Fremont, Madison and Teton Counties .
- West, Terry R. (1995) ´Geology Applied to E ngineering,µ Prentice Hall, New Jersey.
- U.S. Bureau of Reclamation, dam web site http://www.pn.usbr.gov/dams/Teton.shtml
- ´The Failure of Teton Dam,µ U.S. Bureau of Reclamation, News Release (online) av ailable 6/5/2001 (2001).
< http://www.pn.usbr.gov/news/01new/dcoped.html >
8/7/2019 TASK8-Engineering Disasters
http://slidepdf.com/reader/full/task8-engineering-disasters 11/11
10
- ´Teton Dam Failureµ (2002). <http://www.geol.ucsb.edu/~arthur/Teton%20Dam/welcome_dam.html>
- ´Teton Dam Floodµ (2002). <http://www.ida.net/users/elaine/idgenweb/flood.htm> (Dec. 23, 2002) -
Survivor's account