Failure characteristics and mechanism of deposit slopes with bedrock for different soil moisture contents under seismic load

Abstract

The failure characteristics and failure modes of deposit slopes with bedrock under seismic load are different from other types of slopes, due to the influence of the interface between the accumulation layer and the bedrock. In this paper, we describe experiments using a shaking table test (with a self-made model box) to investigate the failure characteristics and dynamic response of deposit slopes with different moisture contents under seismic load. Based on PIV(Particle Image Velocity) technology, we also measured the soil particle velocity field. The experimental results show that the typical failure process of the deposit slope can be divided into a stable stage, a deformation stage, and a failure stage. The water content of the soil has a strong influence on the failure mode of the slope. A slope with lower water content tends to exhibit a local failure mode, and a slope with higher water content is most likely to present an overall failure mode. The motion of soil particles in the slope during an earthquake can be divided into three zones: high speed zone, medium speed zone, and low speed zone. Under our test conditions, the displacement of the slope with high moisture content was smaller than that of the slope with low moisture content under the same seismic load. The critical failure acceleration of the slope increased with increasing water content. The acceleration amplification effect with high water content was weaker than that with low water content. Compared with a homogeneous slope, the slip line of a deposit slope with bedrock will move up and vary as the interface changes.