UNCERTAINTY ABOUT ORIGIN OF PERMANENT DERFORMATIONS ON EXISTING CONCRETE DAMS

Practically all concrete dams exhibit permanent deformations during their lifetime. Generally these deformations take place at an early age of the structure and stop after a few years. However in many cases permanent deformations, even small, continue to increase years after years. Many reasons can be at the origin of such deformations and it is not easy to distinguish between internal and external causes. Often it is also difficult to identify the real cause or causes affecting the behaviour of the dam material, i.e. the concrete itself. Several case histories of Swiss dams are presented where these types of problems have been encountered and attempt has been made to solve them.