Seismic behavior of composite dams of various joint geometries via centrifuge modeling

Abstract

A composite dam which is a combination of a concrete dam and an earth or rockfill dam has been constructed over the decades and has been exposed to earthquakes. This research aims to simulate and to evaluate the seismic behavior of three composite dams with different shapes of the joint, interfaces between concrete dams and rockfill dams using dynamic centrifuge. Three composite dam models were identically constructed except the geometries of the joints. Tests were performed in series of stages with 40g centrifugal acceleration under Ofunato and Hachinohe seismic loadings. The distributions of amplification ratio in the concrete and rockfill model of two composite dams were almost similar. However, the geometry of the composite dam influenced especially the amplification of the joint and the horizontal relative displacement of the top near the joint.