A Micromechanics-Based Model for the Effect of Coupled Damage and Pore Pressure in Rock-Like Materials under Triaxial Tension

Microcracks and microvoids are the main microdefects in rock-like materials, when water infiltrates through a microcrack, an additional opening stress is applied to the surface of microcracks. Based on superposition principle, the response of rock-like materials under triaxial tension and pore pressure is separated into two parts: the first part is the response of materials under hydrostatic pressure and pore pressure in microcracks, the other is the response of materials under far field stress and pore pressure in the microvoids. Based on the analysis of the deformation in a RVE, an additional compliance tensor is obtained. The satisfactory agreement between the computed and experimental results demonstrates the validity of the proposed model.