Abstract:Cracked bedding rock slopes (CBRSs) are numerous in the southwest mountainous area. The action of earthquakes often causes disasters, such as collapses and landslides. The distribution law of the structural plane is herein detailed via field research and references to engineering geological data based on a CBRS project in the southwest mountain area. Moreover, the overall stability of the slope is examined through stereographic projection. On this basis, multiple groups of CBRS models were established through discrete-element UDEC, and their dynamic characteristics and failure modes were analyzed by loading EL-Centro and Kobe waves. Further, the sensitivity of joint parameters to displacement and acceleration responses was studied. The research results demonstrate that the displacement response of the slope first increases and then decreases, and the maximum displacement response of the slope occurs at M4. The PGA amplification coefficient of the slope model clearly demonstrates the elevation amplification effect, and the type of seismic wave affects the PGA response law. The local FFT amplitude drops as the seismic wave crosses the structural plane at the intersection of strong and weak weathering. The CBRS fails under the fracture propagation–sliding failure mode of the strongly weathered rock mass. According to the sensitivity analysis of joint parameters, the spacing of strong weathered joints has the greatest influence on acceleration amplification, whereas the bedding spacing in weakly weathered rock regions has the most pronounced effect on displacement. The numerical simulation analysis reveals the dynamic response law and failure mode of a CBRS under earthquake, which provides a useful reference for further studying the disaster mechanism and preventing such slope occurrences.