Research on Dynamic Failure of Bedrock-Overburden Layered Accumulation Slope Considering Influence of Soil Layer Dip

To investigate the influence of soil layer dip on the dynamic failure of slopes, the failure characteristics and dynamic response laws of bedrock-overburden layered accumulation slopes with different soil layer dips under seismic action were studied based on shaking table model tests. By varying the bedrock-overburden interface dip, three types of slopes with linear, concave, and convex surfaces were designed. Shaking table model tests were subsequently conducted on these slopes, yielding the failure modes of the three types of slopes with various dips. By taking into account the acceleration amplification effect of slope failure, the soil stress state, and the Mohr-Coulomb strength theory, the dynamic response mechanism of slopes and the critical conditions for slope failure were explored. The test results show that the failure characteristics of the concave slope are concentrated in the upper soil layer during the slope failure process, while those of the convex slope are concentrated in the lower soil layer. By contrast, the linear slope exhibits a failure mode characterized by tensile cracking in the upper soil layer and shear sliding in the lower soil layer. Under the same seismic magnitude, the concave slope exhibits the smallest acceleration amplification coefficient, and the acceleration amplification effects of the linear slope, concave slope, and convex slope are concentrated at the slope crest, slope shoulder, and the rear edge of the slope crest, respectively. With the increase in the various dip coefficients, the critical acceleration for slope failure increases accordingly. The research results can provide a scientific basis for the anti-seismic design, stability evaluation, and disaster prevention and mitigation of engineering projects involving bedrock-overburden layered accumulation slopes.