task8-engineering disasters

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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



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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



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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



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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



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Figure 3 The details f igure of Teton Da¡ construction

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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).



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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



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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



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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



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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



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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 >



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- ´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

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