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. ...

The paper by A. M. Penkov and A. S. Bondarchuk summarizes the results of an experimental study of stresses in steel ropes. On the basis of the method developed by the authors it is shown that the discrepancy between the experimental and theoretical data is from 22 to 29% in the direction of reducing the safety margin.