A micromechanical model of inherently anisotropic rocks
Résumé
A micromechanical elastoplastic model is proposed in this study for anisotropic sedimentary rocks. With a two-step homogenization procedure, a macroscopic criterion is established for geomaterials made up of a porous matrix reinforced by rigid inclusions. The effects of porosity, inclusions and the inherent anisotropy are explicitly taken into account. Based on [18], a scalar anisotropy parameter is introduced to describe the anisotropic characteristics of the material. With a non-associated plastic flow rule and a strain hardening law, the proposed model is applied to describe the macroscopic mechanical behavior of Tournemire shale with different initial confining pressures and different loading orientations. Comparing numerical results with experimental data, the efficiency of the proposed micromechanical model is assessed and verified.