Dam Failure Case Studies

1 Causes of Dam failure: Major causes of dam failure are overtopping, sliding, spillway failure etc. A dam may fail because of low standard materials or techniques used. Gleno Dam in Italy is eample which failed due to sub!standard material. "pillway design error is the other probability of dam failure. Geotechnical instability caused by changes to water levels during #lling or poor surveying. Malpasset dam in $rance is eample of poor geotechnical investigation. %ajont Dam in Italy is unique type of dam failure because it did not collapse and is still standing but it appeared to be fatal for neighbors &illing '((( people. Actually the geotechnical engineers didn)t investigated the vicinity so a large volume of roc& felled in dam and displacing and overtopping the water. "ha&idor dam in *asni *a&istan failed because of etreme in+ow. Internal erosion or pipping also causes failure especially in earthen dams. eton Dam is an eample of piping failure.

Case Studies of Dam failure: 2 Machhu Dam (India-1979): 

$ailed on August --, -/.

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he Machchu!' dam, situated on the Machhu 0iver. he failure was caused by ecessive rain and massive +ooding leading to the disintegration of the earthen walls of the four &ilometer long Machchu II dam. he spillway capacity provided for 1223 m45s. he actual observed +ow following the intense rainfall reached -23(/ m45s, thrice what the dam was designed for, resulting in its collapse. During reconstruction of the dam the capacity of the spillway was increased by 6 times and #ed at about '-,((( m45s More than '((( people died.

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3 St. rancis Dam (!S"-192#)  

It was a curved concrete gravity dam, built to create a large regulating and storage reservoir for the city of 7os Angeles, 8alifornia. he dam was designed and built between -'6 and -'2 by the 7os Angeles Department of 9ater and *ower,

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9ater began to #ll the reservoir on March -', -'2. It rose steadily and rather uneventfully, although several temperature and contraction crac&s did appear in the dam and a minor amount of seepage began to +ow from under the abutments. At --:1/pm on March -', -';, the dam catastrophically failed, and the resulting +ood too& the lives of as many as 6(( people. he failure is because of foundation failure according to an investigation committee.

$ig -. "t. $rancis Dam after failure

$ Mal%asset Dam (rance-19&9):  

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he Malpasset Dam was an arch dam on the 0eyran 0iver, he dam was a doubly curved equal angle arch type with variable radius. It was built to supply drin&ing and irrigation water for the region. 8onstruction began in April -1' and was #nished in -16. It collapsed on December ', -1, &illing 6'3 people in the resulting +ood he dam was breached at '-:-3. he entire wall collapsed with only a few bloc&s remaining on the right ban&.

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A tectonic fault was later found as the most li&ely cause of the disaster. alochistan.

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It was constructed in '((3 to provide irrigation for nearby farms.

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