Reasons Analysis and Preventive Measures of Gas Unusual Gush in Xiagou Coal Mine

In order to solve the gas unusual gush problems of ZF301 face of Xiagou Coal Mine, we research the reasons for the phenomenon of gas unusual gush by using gas geological theory, and infer that the existence of fault nearby the face could make the cracks of the coal seams developed, the coal porosity increased, and also make a large amount of free state gas stored in the cracks and could form gas-rich region. Due to the impact of excavation activities at working face, coal wall generated few cracks and communicated with the gas-rich region; the free-state gas in the gas-rich region centrally released into the roadway through the cracks by pressure and gas unusual gush. We analyzed reasons for the phenomenon of gas unusual gush according to the gas producing condition, storage condition and capping condition, and propose a targeted measure which combined coal wall blocking with gas drainage.