Diagnostics of the loss of stability of loaded constructions and the development of the sites of breakdown during the action of seismic explosion and air shock waves

One of the challenging problems for mining enterprises, namely, predicting the decrease in the strength of the structure elements in guarded buildings and constructions during blasting, is solved in terms of a stress concentration factor, the time of exceeding the long-term tensile strength, and the crack growth rate. It is shown that the existence of stress concentrators in the form of natural heterogeneities or defects in the building materials of the building elements subjected to the action of seismic explosion and air shock waves results in crack growth. The distribution of cracks in samples of some materials and the ultimate tensile strength of these materials are determined to find the surface energy. The size distribution of cracks is used to calculate the effective crack length.