Base Sliding Response of Concrete Gravity Dams to Earthquakes

摘要

Two types of analytical procedures are developed considering hydrodynamic effectsto determine the response history of earthquake-induced sliding of a gravity dam monolith supported without bond on a horizontal, planar surface of rock: (1) the dam is assumed to be rigid; (2) dam flexibility is considered with the deformations of the dam approximated by the contribution of only the fundamental mode of vibration. Response results demonstrate that the dam tends to slide only in the downstream direction and dam flexibility has the effect of increasing the sliding displacement. The permanent displacement increases with the intensity of ground shaking and is larger for systems with smaller coefficient of sliding friction, steeper slope of the downstream face, increasing depth of impounded water, or increasing uplift force. The results indicate that the permanent sliding displacements of dams induced by ground motions with peak acceleration of 0.5g may range from a few inches to a couple of feet. The possibility of estimating the permanent sliding displacement of the dam by utilizing previous sliding block analyses is explored.