Abstract:The deformation and failure mechanism of medium-steep bedding rock slopes under earthquake action is relatively complex. A medium-steep bedding rock slope with a rock dip angle greater than the slope angle was designed and fabricated using shaking table tests. The dynamic response characteristics and failure modes of the slope were examined under unidirectional and coupled seismic wave actions. The experimental results reveal a distinct nonlinear elevation amplification effect on the horizontal dynamic acceleration of the model slope. Remarkable nonlinear amplification and surface effect were observed within a depth range of 20 cm from the slope surface. Moreover, the dynamic response of the slope is more pronounced under coupled seismic waves. Under low amplitude and low frequency conditions, the slope exhibits a stronger dynamic response to natural waves than to sine waves. The peak horizontal acceleration (PHA) amplification factor of the slope increases with the amplitude. As the frequency increases and approaches the natural frequency of the slope, the PHA amplification factor experiences a significant increase. Coupled seismic waves further enhance the PHA amplification factor across various waveform, amplitude, and frequency conditions. Compared with other seismic waves, coupled seismic waves exert a more destructive impact on the slope. The failure process of medium-steep bedding rock slopes under earthquake action can be categorized into three stages: crack generation at the upper part of the slope, crack expansion and penetration, and sliding in the upper slope region, leading to slope instability.
