The concept of slipping and rock mechanics

Shear strength is considered as the basic strength characteristic of the material in the developed concept of slipping. The experimental data obtained by A. N. Stavrogin on the uneven triaxial compression of cylindrical rock samples are reviewed. A unified dependence of purely plastic deformation on the level of stress is established for all types of stress state. The elastic component of deformation is considered, from the standpoint of physical nonlinear elasticity theory as well. The coefficient of material loosening is determined. A method is suggested for preparation of the certificate of rock strength based on the experimental data for uniaxial compression only and known properties of the envelope of Mohr's circles.