Study On Comprehensive Gas Control Scheme For Upper Protective Seam Mining In Xiayukou Coal Mine

Coal and gas outburst is the main disaster restricting the safety production of Xiayukou coal mine.2#and 3#coal seam are outburst coal seams.Objectively speaking,the outburst risk of 2#coal seam is less than 3#coal seam,which can be used as upper protective layer.In order to ensure the safe and efficient production of Xiayukou coal mine,In this paper,the comprehensive control scheme of gas in protective seam mining is studied.Based on the investigation of gas geological conditions in Xiayukou Coal Mine,this paper analyzes the danger degree of coal seam outburst and the feasibility of protective seam mining.Taking 23206,23208 and 23306 coal faces as research background,the pressure relief range of protected layer is determined by using numerical simulation method,at the same time,the deformation evolution process of coal body in protected seam face is analyzed,which provides the basis for the next comprehensive gas control.On the basis of numerical simulation and combined with mine practice,comparison and analysis of gas control scheme in protective seam mining,the gas control scheme of using the strip gas of the pre-drainage coal roadway drilled along the seam as the protective seam mining is determined,on this basis,the investigation scheme of,protective seam mining effect,the gas extraction scheme of 3#coal seam,the gas comprehensive control scheme of 2#and 3#coal seam are worked out,and various investigation measures are worked out in detail.According to the technical scheme of comprehensive gas control,the related data are collected and analyzed,including the mining effect of Protective Seam,the pressure relief effect of 3#coal seam and the comprehensive gas control effect of protective seam.The maximum relative expansion and deformation rate of 3#coal seam is 12.9‰,which is much higher than the critical index.Through engineering application,site investigation and effect analysis,the feasibility of protection layer mining scheme,pressure relief gas drainage scheme and protection layer gas control scheme is verified,and good economic and social benefits are obtained.