In the general complex of questions on the destruction of rocks an important place is occupied by the development of the theory of strength and improvement of methods of their testing. As a result of this research, new ideas about the properties of rocks and the mechanism of their fracture have emerged. This article deals with the matter of the relationship between the theory of strength and the mechanism of fracture and provides methods of constructing stress diagrams and their interpretation. ...

In all real bodies, deformation processes proceed in time. Mechanical characterizations that do not take time into account are approximate and in many cases prove to be inadequate. Factors such as the rate and duration of loading, the energy stored by the system have a great influence on the value of the breaking stress. In LMI a lot of work has been done to establish the physical features of the process of rock fracture by shock loading and to find out the comparative efficiency of static and dynamic methods of fracture. As a result, it was found that the fracture energy, other things being equal, is a function of the impact energy, the velocity of the impact load application, and the mass of the striking body. As for the comparison of energy expenditure in static and impact tests, it is permissible only at a comparable degree of crushing, i.e., at some minimum impact work.