Seismic performance of small earth dams with sloping core zones and geosynthetic clay liners using full-scale shaking table tests

In Japan, a large number of old small earth dams are in critical need of repair due to leakage and poor earthquake resistance. In addition to cohesive soils, geosynthetic clay liners (GCLs) are used as impervious materials to repair such dams. This paper discusses the seismic performance of small earth dams, with reservoirs on their upstream side, repaired with a sloping core zone and a GCL on the basis of the results of full-scale shaking table tests performed at the E-Defense facility. The main focus is on the differences in mechanical behavior between the upstream and downstream sides of the dam. The results elucidate that the effective stress of the upstream embankment materials increased because of the undrained shear behavior of the compacted soils, although the deformation on the upstream side was larger than that on the downstream side. A large phase difference in the measured accelerations between the upstream slope and the downstream slope was also observed. Therefore, it is concluded that significant differences occurred in the dynamic behavior of the upstream side and the downstream side.