An Investigation on the Estimation Methods for the Equivalent Mohr-Coulomb Strength Parameters of Generalized Hoek-Brown Rock Mass

Abstract

Many practical engineers are often accustomed to understanding the strength of the rock mass in terms of friction angle and cohesion. Therefore, it is necessary to provide a resonable tool implementing the Generalized Hoek-Brown (GHB) failure condition in the framework of the Mohr-Coulomb (M-C) criterion. In this study, the features of Lee (2015) and Hoek et al. (2002) methods for calculating the equivalent friction angle and cohesion of GHB rock masses were briefly reviewed. Subsequently, in order to compare the accuracy of the two methods, the ultimate bearing capacity of strip footing resting on the M-C rock mass was assessed by performing the 2D FE analysis incorporating the equivalent M-C strength constants from both approaches. The results show that Lee (2015)’s method, which exploits the upper bound solution of ultimate bearing capacity, is superior to that of Hoek et al. (2002)’s approach.