Authors: А. Sysoev, D. Batrakov

Title of the article: Theoretical assessment of the size of the fracture zone during the explosion of borehole charges based on the energy approach

Year: 2024, Issue: 5, Pages: 81-88

Branch of knowledge: 2.8.6. Geomechanics, destruction of rocks by explosion, mine aerogasdynamics and mining thermophysics

Index UDK: 622.235.5

DOI: 10.26730/1999-4125-2024-5-81-88

Abstract: The size of the destruction zone around the borehole charges used in the explosive preparation of rocks during the open-pit mining of mineral deposits determines the main parameters of drilling and blasting operations, including the size of the grid of wells, the length of the drilling and downhole space, as well as such possible structural elements of the borehole charge as the length of the dispersal gaps and the length of the bottom part of the well free of explosives. The estimation of the size of the zone of conditional crushing is essential for relatively small values of the height of the continuous part of the charge, which occurs, in particular, when creating dispersal gaps. In this paper, a theoretical assessment of the size of the fracture zone during the explosion of borehole charges is considered on the basis of an energy approach, according to which it is assumed that the volume of the resolution zone is proportional to the mass of the explosive charge. Calculation formulas have been obtained for the geometric dimensions of the conditioned crushing zone depending on the height of the explosive charge column, the diameter of the wells and the rock strength. Using experimental data available in scientific publications, the limiting values of the length of the charge dispersion interval and the bottom part of the well free of explosive, the length of the continuous parts of the concentrated charge, which can be used without changing the size of the well grid compared to the basic design of the row, were determined. The proposed method makes it possible to justify the design of borehole charges in the presence of gaps free of explosives. The energy principle widely used in the theory of explosion, as well as the logically justified dynamics of the geometric shape of the crushing zone from spherical to cylindrical (as the length of the continuous part increases) of the charge, are signs of the adequacy of the method.

Key words: cut borehole charge destruction zone conditioned crushing

Receiving date: 11.05.2024

Approval date: 29.09.2024

Publication date: 24.10.2024

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