Seismic Response Mechanisms of Rock Slopes With Varied Lithologies and Discontinuities: Numerical Insights From the Donghekou Landslide

ABSTRACT Rock slopes with different mechanical properties and structural configurations exhibit distinct dynamic responses under seismic action. Taking the 2008 Wenchuan earthquake‐induced Donghekou landslide in China as a case study, this study established discrete element numerical models for slopes with different lithological structures, joint sets and tunnel configurations to investigate the dynamic response characteristics of the slope surface under various loading directions and seismic peak accelerations. The results indicate that the surface acceleration of slopes increased with elevation and demonstrated the strongest amplification effect under vertical loading. The greater the mechanical strength of the rock, the weaker the acceleration amplification effect of the slope, resulting in stronger slope stability. Weak layer, joints and internal tunnels had significant effects on the acceleration response of slopes, with localised acceleration amplification phenomena occurring near weak layers and joint surfaces. Unlined tunnels amplified the acceleration response, while lining reduced the dynamic effect. This study on the seismic response of rock slopes not only contributes to revealing the underlying microscopic failure mechanisms, but also provides valuable insights for dynamic stability analysis of rock slopes and prevention of earthquake‐induced landslide disasters.