ABOUT THE PRE-OUTBURST STATE OF THE COAL AND SANDSTONE AND THE POSSIBLE MECHANISM OF COAL AND GAS OUTBURST PROCESS

Abstract

The paper aims to examine the suitability of A. S. Balankin brittle fracture criterion in predicting the of large-scale coal and gas outbursts in underground coal mines under compression load. Formation of dissipative structures as cracks and clusters of local microcracking occurs under the influence of the rock pressure. The formation of microdefects in dissipative structures occurs mainly on local anisotropic inclusions. Mechanism of pre-outburst spalling of gas-saturated coal is analyzed. Destruction (primary outburst) occurs when the brittle fracture conditions are met. And also in the case of such a ratio of “coal seam thickness – the size of micro defects aggregations”, which provides reduction in coal strength to a minimum. Further destruction occurs by known scenario.