Shaking table model test and numerical analysis of the steeply dipping bedded rock slopes under seismic actions

Based on large-scale shaking table model tests and the particle flow code PFC2D, this study investigates the failure characteristics of steeply dipping bedding rock slopes and the failure modes of the slope's locking sections under seismic dynamic actions. The results show that the deformation and failure evolution process of the slope under seismic wave loading can be divided into four stages: the generation of tensile cracks in the rock strata at the slope top, the downward propagation of tensile cracks along the bedding planes until the formation of locking sections at the slope toe, the shear fracture of locking sections and the penetration of sliding surfaces, and the sudden instability and sliding of the slope, with the failure mode being tensile-shear pushing sliding failure. Combined with the results of shaking table model tests and numerical simulations, it is concluded that the sliding failure surface of steeply dipping bedding rock slopes under seismic action is composed of the bedding planes of rock strata and the shear fracture surfaces of locking sections, and the fracture mode of the slope's locking sections is shear failure caused by the combined action of seismic inertial force and overlying load. With the gradual increase in the dip angle of rock strata, the failure mode of steeply dipping bedding rock slopes gradually transforms from shear-slip failure to inward progressive tensile fracture failure. The thickness of rock strata has little influence on the failure mode of steeply dipping bedding rock slopes and the fracture mode of locking sections, while the model slopes with thinner rock strata exhibit more severe sliding failure compared with those with thicker rock strata.