Mechanical Properties and Conditions of the Rock

A massif is a structurally isolated part of the Earth's crust that is influenced by anthropogenic human activity, which alters the initial state of natural equilibrium. The existence of subsequent forms of equilibrium depends on mechanical parameters that characterize the properties and conditions of occurrence of the rock massif. Thus, after excavation, the rock massif becomes a natural structure that, depending on the intensity of concentrated stresses on the one hand and the deformation characteristics of the rock on the other hand, can ensure the serviceability of the object independently or together with the artificial part of the underground structure—the support. Consequently, the assessment of the stability of the excavation and the possibility of fulfilling its purpose at the lowest cost is possible only with a good knowledge of the mechanical parameters of the rock, which vary within very wide limits.