A STATISTICAL THEORY OF BRITTLE FRACTURE FOR ROCK MATERIALS .2. BRITTLE FAILURE UNDER HOMOGENEOUS TRIAXIAL STATES OF STRESS

The critical volumetric microcrack strain criterion outlined in Part I is extended to include total failure of brittle materials deformed under a condition of homogeneous triaxial loading. It is shown that the criterion indicates the fracturing characteristics of brittle rock materials are influenced by the value of the intermediate principal stress. The influence of material heterogeneity upon the fracture characteristics of brittle rock is discussed. The analysis indicates that the failure envelope is nonlinear and that the degree of nonlinearity tends to diminish as the confining pressure is increased. © 1969.