ABSTRACT
One of the important parameters necessary for the calculation of the response of dams is the effect of the added mass caused by the existence of the water in the reservoir. The calculation of this added mass for the Emosson Dam is included as Appendix G. In this particular case, at the time of testing, the water level was 7 m below the level of the spillway. The mass of the dam measured from the induced vibration test was 20.55 x 108 kg, and that inferred from the design drawings is 22.18 x 108 kg. It is often assumed that a mass equivalent to 40% of the mass of the dam needs to be added to account for the mass of water being moved by the motion of the dam. Clearly, in this case, that theory is not confirmed. However, it must be remembered that the water level was 7 m below spillway, and that the effect may be more pronounced when the water level is at its maximum. No further tests on dams under induced vibration have been conducted in the last 20 years, and so it is still not possible to confirm whether the 40% added mass theory is correct or not.
