Bedding slope damage accumulation induced by multiple earthquakes

The 2017 catastrophic Xinmocun landslide was triggered on a bedding slope in the Songpinggou Gully, Maoxian County, China. Previous research primarily focused on the dynamic slope response and deformation characteristics of a single earthquake, and focus on the effect of damage accumulation on slope stability is lacking. The shaking table tests were conducted in this study to understand historical earthquake-induced damage accumulation in bedding slopes. The acceleration amplification coefficient (BPGA) and plastic effect coefficient (PEC) were used to reflect the damage accumulation of bedding slope under the influence of multiple earthquakes. The results revealed that the bedding surface-induced seismic motion amplification contributes to damage constrained on the slope sliding surface. The damage accumulation during multiple earthquakes contributed to slope peak ground acceleration (PGA) amplification increasing and model's natural frequency decreasing in non-linearly form. The shortening of the gap between the driving force frequency and the model's natural frequency had a great impact on the slope damage accumulation. These findings suggest that the accumulation of damage caused by historical earthquake amplification contributes significantly to post-earthquake instability. Future evaluations of slope stability should consider the accumulation and reduced frequency of slope deformation associated with multiple earthquakes.