Session 1: Discussion

SEISMICITY

Mr P. Londe (Session Chairman; President of ICOLD). Earthquakes have always been known to be the most destructive and the most unpredictable of all natural calamities. However, only a few case histories of damage to dams have been reported and, at present, the assessment of the risk caused by earthquake is still of a speculative nature in relation to dams.

The damage so far observed on dams after earth

quake is

(a) Concrete dams : only five dams are known to have suffered minor or moderate cracking. None have collapsed.

(Rohem L.H. and Hansen K.D., Water Power, April, 1979).