ABSTRACT
The case of Wimbleball Dam is particularly interesting from this point of view. The dam is a concrete buttress type, and is shown in Fig. 6.47. When the reservoir level is lower, then these individual sections behave independently. Figure 6.48 shows the response of the dam, which was recorded as a series of synchronized vibrators, set on the crest of the dam to induce motion in the fundamental upstream-downstream mode of vibration, were switched off. It can be seen that each buttress undergoes an individual response that is different from its neighbours. It can also be seen that in some cases the response becomes greater before decaying. Such an increase can only occur if energy is transferred in from one of the other buttresses.
