About one criteria of strength of rocks

Plastic deformation of rocks and generation of residual deformation field are related to shear and tensile cracks formation. For conditions of three-dimensional stress state a strength (yield) criterion is proposed that takes into consideration combined effect of two kinds of failure (shear and tensile failure) and is based on associated flow rule. The developed criteria relations were verified during description of results of rocks mechanical tests. Acceptable concordance between calculated and experimental values of breaking stresses and strains was obtained. Developed algorithm for critical stresses, elastic and plastic deformations determining is easy enough for numerical realization in three-dimensional problems of mathematical modelling of deformation and failure processes of large-scale mine technical objects.