ABSTRACT
The experience with the seismic behaviour of large dams is still limited. Four dams, two concrete, an earth core rockfill and a concrete face rockfill dam, with heights exceeding 100 m were damaged during the Wenchuan earthquake. Elsewhere, there are another five concrete dams over 100 m in height, which were damaged due to strong ground shaking. In concrete dams the damage was mainly in the form of cracks but also joints can open up leading to the release of water from the reservoir. In modern embankment dams the damage is mainly by deformations and cracks along the crest that can eventually lead to internal erosion and piping through the dam. At this time, people are still in a learning phase as very few large modern dams have been exposed to strong earthquakes. Surface powerhouses were particularly vulnerable to rockfalls in the steep valleys in the epicentral region of the Wenchuan earthquake.
