Continuous ambient-vibration monitoring of the arch dam of Mauvoisin

This paper presents the experimental programme and results of a continuous ambient vibrations recording programme carried out on the 250m arch dam of Mauvoisin. This project follows a series of previous measurements completed for seven different water levels. An automated system was set up on the dam and the ambient vibrations were recorded twice daily for a period of 6 months. Frequency shifts were tracked throughout the testing period and the effects of the varying water level were identified. The results confirmed the behaviour observed in previous ambient- and forced-vibration tests. The added-mass effects are overcome by the stiffening of the dam due to increasing hydrostatic pressure for lower reservoir levels. This trend is then reversed for higher water levels. Any temperature-related effects were not identified. The experimental techniques are briefly described and the frequency identification process and its limitations are discussed. Copyright (C) 2001 John Wiley Sons, Ltd.