The practice of construction of vertical shafts by the drilling and blasting method in the conditions of the combine “Rostovshahtostroy” shows that the improvement of parameters of drilling and blasting works allows a reduction of the deviation of actual cross‑sections from the design. At the same time this is not accompanied by a reduction of irregularities of the rock walls of the shaft, and the destruction of rocks in exposures remains still significant.

Since 1966, the Leningrad Mining Institute together with Rostovshahtostroy Combine have been conducting research to determine the actual over-excavation of rock during the sinking of vertical shafts and to find the optimal parameters of contour blasting, contributing to the reduction of excessively excavated rock.