SIMULATION OF COAL OUTBURST BY BLASTING BOREHOLE CHARGE
The mechanism of blasting destruction of coal is considered using a combined model of gas-saturated coal, which describes the relationship between explosive damage of a coal seam and subsequent gas release. On the basis of this model, the numerical method of smoothed particles is used to study the development of destruction zones and stress-strain state of a coal seam in the vicinity of a borehole charge after blasting. The obtained patterns help to predict the reaction of coal to explosive dynamic impact. This may be of considerable interest for the development of technology for preliminary degassing of coal seams, as well as for theoretical description of the processes occurring during coal and gas emissions. In this regard, the preparation mechanism of gas-dynamic fracture of a stack of outburst-hazardous (broken) coal under explosive action on a coal seam is considered. The research includes studying the conditions for crack formation in the zone farthest from the blast hole, modeling the filling of induced cracks with methane, which is initially in the coal in a dissolved state, and estimating the onset time of induced crack propagation due to free methane pressure in the crack. It was found that, depending on the mechanical and diffusion parameters of coal, the crack initiation time can vary from tens of seconds to many hours. The research results can be useful in the development of a theory of explosive action on a coal seam, which is used in a set of measures to reduce the hazard of sudden coal and gas emissions.