A methodology has been developed and experimental studies have been carried out to evaluate structural changes in rock samples in the near zone of explosion action. Using optical microscopy and X-ray structure analysis, it was found that the microstructure of rocks changes during the passage of shock waves: the dispersion of mineral grains increases, and the density of micro-disturbances increases by an order of magnitude.

The problem of rock pre-fracture under quasi-static and di-namic loading is considered. It is shown that under dynamic loading it is possible to form pre-fracture zones of large extent. The data of ultrasonic measurements after non-destructive explosive loading are presented. Experimental data on changes in the velocities of elastic wave propagation after dynamic loading are presented.