Stability charts for rock mass slopes based on the Hoek-Brown strength reduction technique

Abstract

This study presents stability charts for estimating the stability of rock mass slopes that are suitable for the generalized Hoek-Brown (GHB) failure criterion based on the strength reduction technique. First, in order for implementing the GHB strength reduction, the estimation for the local Mohr-Coulomb (MC) friction angle and cohesive strength from the GHB criterion was incorporated into the strength reduction process in ABAQUS 6.10. Second, stability charts for calculating the FOS of rock slopes with a specific slope angle of β=45° and D=0 are proposed based on this method. Third, the disturbance weighting factors fD and slope angle weighting factor fβ are used to quantify the effect of the rock mass disturbance factor and slope angle on the rock slope stability evaluations. Combined with the stability charts based on β=45° and D=0, the weighting factor fD and fβ can be used to calculate the FOS of rock slopes with various slope angles under different blast damage and stress relief conditions. Finally, the stability charts were applied to two real case studies to illustrate the applicability and validity. The results for the two cases demonstrated good agreement with those from the other charts and the FEM software ABAQUS 6.10. The proposed charts provide a simple and straightforward way to estimate the FOS of the rock mass slopes directly from the GHB parameters.