Rock slope stability analysis considering three-dimensional stress and strength

This paper proposes an analytical approach for analyzing rock slope stability based on a three-dimensional (3D) Hoek-Brown (HB) criterion to consider the effects of 3D stress and strength. The 3D HB criterion, considering an associate flow rule, is utilized to describe the perfectly-plastic behavior of rock under a plane strain condition. To reflect the change of friction angle on the failure surface, the potential failure surface (PFS) is divided into small segments with each segment being assigned a unique friction angle. The upper bound limit analysis is combined with the strength reduction method to determine the factor of safety (FOS) of a rock slope with a defined PFS. By optimizing the PFS, the minimum FOS and the critical failure surface (CFS) are obtained by a customized genetic algorithm. The proposed approach is validated by comparing it with HB criterion-based numerical and analytical methods. The results indicate the importance of considering 3D stress and strength in rock slope stability analysis.