An experimental evaluation of ice cover effects on the dynamic behaviour of a concrete gravity dam

An extensive forced-vibration testing programme has been carried out on an 84-m concrete gravity dam located in northeastern Quebec, Canada. The dam was subjected to a harmonic load on the crest in summer and severe winter conditions with temperatures ranging from -10degreesC to -15degreesC and a 1.0-1.5 m ice cover. Acceleration and hydrodynamic frequency responses were obtained in different locations on the dam and in the reservoir. The main objective of the repeated tests was to investigate the effects of the ice cover on the dynamic behaviour of the dam-reservoir-foundation system, by comparing summer and winter results. Modifications in damping and resonance frequencies were observed, as well as an additional resonance that was attributed to an interaction of the dam with the ice cover. These findings provided a reliable and unique database for the investigations of dam-reservoir-foundation interaction and, in particular, the ice-cover effects for dams located in northern regions. Copyright (C) 2002 John Wiley Sons, Ltd.