An Extension Strain Type Mohr–Coulomb Criterion

Abstract Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In past, simple empirical criterion fracture initiation in brittle rock has been developed. this article, it is shown that makes unrealistic strength predictions biaxial compression and tension. To overcome major limitation, new proposed adding weighted principal shear component to The weight chosen, such enriched represents same surface as Mohr–Coulomb (MC) Thus, MC derived an predicting modes, which unexpected classical understanding of cohesive-frictional materials. progressive damage rock, most likely direction orthogonal maximum leading dilatancy. threshold crack CI CD at peak stress CP. Different from compressive loading, tensile loading requires only limited number critical cracks cause failure. Therefore, stresses, criteria must modified somehow, possibly cut-off corresponding stress. Examples show predicts much lower volumes damaged mass compared