Seismic stability of the planar sliding rock slope considering the rough structural plane strength degradation

Current methods for calculating the seismic stability of planar sliding rock slopes inadequately account for the effect of structural plane roughness and tend to overestimate the influence of vibration wear and relative movement velocity on strength degradation. To address these limitations, theoretical analysis was conducted. Based on the comparative analysis of the commonly used structural plane shear failure criteria, Barton criterion, which can consider the structural plane roughness, was selected as the structural plane shear strength criterion. It is assumed that the vibration wear affects only the structural plane roughness, not the basic friction angle. Meanwhile, the relative movement velocity influences the friction coefficient rather than the friction angle. Thus, a revised calculation formula for the seismic stability coefficient of the planar sliding rock slope was proposed. The parametric sensitivity analysis was adopted to analyze the influence of the peak ground acceleration of the seismic wave, the basic friction angle and roughness coefficient of the structural plane, and the influence parameters m and P₀ of the structural plane shear strength degradation factor on the slope seismic stability. It is found that with the increase of the peak ground acceleration and m, the slope seismic stability decreases, while the basic friction angle, roughness coefficient, and P₀ of the structural plane have the opposite effect on the slope seismic stability. This study can provide valuable information for the slope seismic stability analysis.