Investigating Deformation and Failure Mechanisms of Discontinuous Anti-dip Bench Rock Slopes Through Shaking Table Tests and Numerical Simulations

Large-scale shaking table tests and numerical simulations were conducted to investigate the deformation and failure mechanisms of an anti-dip bench rock slope with discontinuities. The study introduces the Displacement Baseline Offset Ratio (DBOR) to characterize the instability and failure processes of slopes when they reach a plastic state under seismic excitations. It examines the peak ground displacement and earth pressure responses, as well as the cumulative damage processes of the slope model to provide insight into the deformation and failure mechanisms. The results show a significant displacement amplification effect at elevated points of the slope when subjected to seismic excitations. Furthermore, as the input frequency of the sine wave increases, the amplitude of the displacement response at the upper part of the slope accelerates. The widest bench divides the entire slope into smaller segments, hindering the deformation and failure across the benches and reducing stress transfer from the upper slope, thereby preventing stress concentration at the toe of the slope. The distribution of DBOR suggests that plastic deformation is more pronounced on the inner side of the bench than on the outer side, leading to earlier cracking on the inner side. A critical displacement threshold for seismic damage of each bench is established based on residual displacement responses and critical peak acceleration. These findings provide theoretical references for the risk assessment and seismic design of bench rock slopes.