Seismic stability evaluation of benched bedding rock slopes with varying landforms

Seismic stability of rock slopes is a critical issue in geotechnical engineering, particularly in seismically active regions where benched bedding slopes are susceptible to dynamic failure. This study explores the dynamic response and progressive damage mechanisms of benched bedding rock slopes under seismic excitation through shaking table tests and numerical simulations. Specifically, four slope models with varying bench widths are analyzed, focusing on key factors such as acceleration amplification coefficients (AAC), earth pressure distribution, and failure modes. The results reveal that AACs at the internal corners of benches are lower than those at the external corners. Moreover, it is observed that slope stability improves as the bench width increases, as evidenced by a reduction in failure occurrences for slopes with uniform bench widths of 2 m, 4 m, and 6 m. In contrast, the slope with uneven bench widths exhibits more severe failure. Furthermore, numerical simulations confirm that slopes with wider platforms at lower elevations are more prone to bench-scale failure. To quantify these effects, a novel dynamic stability equation, Sqt, validated by test data, classifies stability into four levels: Sqt < 1.0 (unstable), 1.0 < Sqt < 1.3 (less stable), 1.3 < Sqt < 1.5 (basically stable), and Sqt > 1.5 (stable). These findings provide a necessary basis for understanding the shattering cumulative damage mechanism and seismic fortification of complex rock slopes, and offer valuable insights for the design of cutting slopes in high-intensity seismic areas.