Pseudodynamic Approach for Rock Slopes in Hoek–Brown Media: Three-Dimensional Perspective

Abstract

Pseudodynamic (PD) method is a novel method that has the merit of considering the temporal and spatial effects of earthquake input in seismic stability analysis. Currently, most PD analyses adopted the two-dimensional (2D) plane-strain assumption, which is inconsistent with the fact that many slope collapses have distinct three-dimensional (3D) features. To address that, a 3D PD method was proposed in this paper for rock slopes yielding Hoek–Brown criterion. The present method was established on the one-block mechanism in the kinematic analysis, since this mechanism has considerable efficiency in 3D safety factor computation. The details of the 3D PD method are elaborated herein, including failure mechanism, energy balance equation, and strategy of fining solutions. The effects of temporal–spatial variation of seismic input on slope stability are discussed using the proposed approach. The study reveals that phase change and acceleration amplification have contrary effects on rock slope stability, and which factor dominates determines whether PD analyses result in overestimated or underestimated safety factors than classical PS analyses. Finally, a parametric study is performed to investigate the influences of rock strength, slope geometry, and earthquake parameters in PD analysis.