| Abstract: | The Koyna Dam in India was subjected to a severe earthquake on 11 December 1967 with its epicentre very close to the dam site. During this earthquake, higher non-overflow monoliths of the dam suffered significant damage. In the highest non-overflow monolith, a horizontal crack occurred at the level where there was an abrupt change in the downstream slope. The dynamic behaviour of the top profile of this monolith of the dam above the crack has been investigated treating it as a rigid body. The study shows that the overturning of the cracked portion of the dam will not occur due to the severest anticipated ground motion at the site. However, to prevent the seepage of water and as a permanent remedial measure, strengthening of the dam is necessary but no emergency measures need be taken. |
