Probabilistic Modeling of Shear Strength of Rock Discontinuities Using Direct Shear Test Data

Available literature on the topic is reviewed. Methods are suggested to improve the presently available techniques to perform probabilistic modeling of shear strength parameters for rock discontinuities. The Mohr-Coulomb model and a power law model are used as strength criteria to model shear strength of rock discontinuities. Use of various regression techniques for point estimation of shear strength parameters from direct shear data are discussed. Goodness-of-fit tests for bivariate beta and bivariate normal distributions are developed, and the applicability of them to represent the distribution of shear strength parameters is tested through examples. Both distributions seem to have potential to represent the statistical distribution of strength parameters.