The failure of transversely isotropic rocks in triaxial compression

Abstract The theoretical predictions obtained from a recently developed theory of the failure conditions for orthotropic solids are compared with experimental results on the failure of transversely isotropic rocks. It is shown that the theory satisfactorily predicts the variation of strength and of the inclination of the failure plane as functions of cleavage or bedding orientation with respect to the directions of the applied principal stresses. The material parameters necessary to completely determine the failure condition and the failure plane are only four. The procedure for their identification is outlined. The possible use of the proposed criterion in solutions of boundary value problems with the finite element method is suggested.