Constitutive model for inherent anisotropic rocks: Ubiquitous joint model based on the Hoek-Brown failure criterion

This paper proposes an elasto-perfect plastic constitutive model (called Jhoek) linking two failure criteria to model the sliding and non-sliding failure modes of anisotropic rocks. For non-sliding failure mode, modified Hoek-Brown criterion with an explicit function of the rock parameter m(i) with orientation beta is applied, while the single plane of weakness is simulating the sliding failure mode. Published experimental datasets of anisotropic rocks are used to validate this model. Jhoek could predict failure envelopes of rock samples under triaxial loading conditions at different orientation angles. Besides that, Jhoek model shows sensitivity to the intermediate principal stress in 3-dimensional cases.