Simulation of coal and gas outbursts in outburst-prone zones of coal seam

Abstract

The problem of mining safety in outburst-prone coal seams has not yet been ful-ly studied and resolved, so research related to outbursts continues to be relevant for many coal-mining countries. The purpose of this work is to study the coupled pro-cesses of elastoplastic deformation of a coal seam, methane filtration and desorption, which occur in the outburst-prone zone of the coal seam, and to establish the regu-larities of their joint flow. Numerical simulation methods were used to solve this problem. Simulation of the joint flow of geomechanical and filtration processes in the outburst-prone zone, on its border and beyond it was made. The regularities of changes in geomechanical and filtration parameters in the near-face zone of the coal seam, as well as the regularities of the influence of moisture on the outburst hazard, were established. The developed numerical model allows to identify a safe limit of moisture saturation, at which the nature of geomechanical and filtration processes in the coal seam are quasi-stationary but not dynamic for the specific geological condi-tions. The influence of the unloading chink on gas-dynamic processes was studied. It was shown, when using an unloading chink, a zone completely unloaded from rock pressure is formed near the mine face, in which the occurrence of cracking and destruction processes is excluded. The use of the unloading chink significantly slows down the process of fracturing, which prevents the onset of dynamic phenomena. Key words: coal and gas outburst, coupled processes, elastoplastic deformation, methane filtration, mining safety, moistening, numerical simulation, unloading chink.