Investigation on cumulative response evolution and stability assessment of rock slope under mainshock and aftershocks

Abstract

Landslides triggered by seismic events significantly threaten the safety of rock slopes. However, the cumulative response evolution of the rock slope under main and the subsequent aftershocks remain poorly understood. In this study, a simulation-based assessment method for assessing the rock slope stability subject to main and aftershocks was proposed. By employing transfer function, variational mode decomposition and Hilbert transform, this method can systematically describe the cumulative dynamic response evolution of rock slope during main and aftershocks from the time, frequency, and time–frequency domain, respectively. Base on this, the rock slope stability was assessed using the weighted sample entropy. The proposed assessment method was firstly applied to analyze the cumulative response evolution and rock slope stability at Dagangshan Hydropower Station during Luding earthquakes. The results shows that the frequency-domain parameters are particularly effective in determining the variation of rock slope stability under the seismic events with a relatively high magnitude. And the time-domain and time–frequency-domain parameters exhibit higher sensitivity in assessing the cumulative effect on the rock slope stability during continuously lower-magnitude seismic events. The instability of the rock slope continuously increased during the mainshock and the first three aftershocks, while gradually remained stable at the fourth aftershock of Luding earthquakes. Moreover, the proposed method has been successfully employed to assess the rock slope stability during the seismic events of varying magnitudes. It proves to be particularly effective for high-magnitude seismic events. The research findings provide a valuable practicable assessment method for earthquake disaster prevention strategies for actual slopes.