IMPROVING THE QUALITY OF BLASTING INDICATORS BY STUDYING THE NATURAL STRESS FIELD AND THE IMPACT OF THE BLAST FORCE ON THE ROCK MASS

In the proposed article two different methods of blasting horizontal and inclined mine excavations are considered. The purpose of this article is to increase the stability of the contour rock mass and improve the quality of the blast by optimizing the parameters of drilling and blasting operations during the passage of underground mine excavations. When choosing the research method were used modern programs and methods for determining the zones of influence of the blasting force. On the basis of numerical modeling by the finite element method are determined the possible zones of destruction of law-shaped rocks under the influence of the blasting force. A comparative analysis of the excess cross-section coefficient of two different methods of blasting sinking excavations is performed. There are shown the advantages and disadvantages of the method of contour blasting of sinking excavations proposed by the authors. The design of the charge of contour holes and the explosives used in the proposed method of detonation are demonstrated. The actual results of experimental explosions are given. It is shown how much the quality indicators of blasting operations increase in comparison with the generally accepted methods of blasting sinking roadhead. By reducing the force of the blast on the sculptural rock mass, the surface of the uncovering contour of the excavations is more even, which allows to choose a lighter support to mine excavations in a stable state.