Investigation On The Effect Of Overburden Deformation And Pressure Relief On The Lower Protective Layer Of Wulunshan Coal Mine

Coal and gas outburst have always been one of the factors hindering the safe and efficient mining of coal mines.As a kind of regional anti-burst measures,the protective layer mining technology has been widely promoted and applied,and has achieved good results in field practice.Based on Guizhou Wulunshan Coal Industry Co.,Ltd.?hereinafter referred to as“Wulunnshan Coal Mine”?,this paper selects the main mining 6^-3 coal seam and 8coal seam as the research background,and the 8 protruding coal seam as the protective layer.The upper 6^-3 protruding coal seam acts as a protected layer,and through the mining of the 8 coal seam,the pressure relief of the 6^-3 coal seam is reduced,the coal and gas outburst are reduced,and safe and efficient mining is realized.In this paper,theoretical analysis,numerical simulation and industrial field combination research methods are used to theoretically analyze the movement law of overlying strata affected by mining.The numerical simulation software is used to simulate the protective layer of Wulunshan Coal Mine?8 coal seams?.The stress change of the coal-rock under the protective layer(6^-3 coal seam)and the deformation law of the displacement after the mining;the distribution of the stress distribution of the protective layer after the lower protective layer of Wulunshan Coal Mine shows the distribution of"W"However,the distribution of coal thickness deformation in the vertical direction of the protective layer shows the distribution pattern of“M”.Finally,the pressure relief range of the lower protective layer mining in Wulunshan Coal Mine is determined and the protection effect is investigated..It is concluded that the pressure relief angle of the lower protective layer of Wulingshan Coal Mine is 83°at the upper part and 77°at the lower part.The pressure relief angle along the strike is 58°;in addition,the maximum gas content and gas pressure of the coal seam are reduced from 14.19m³/t and 1.3MPa to5.81m³/t and 0.69MPa respectively,which are less than the critical value of 8m³/t.,0.74Pa.It shows that the Wulunshan Coal Mine has been mined through the lower protective layer,and the protective layer has been fully relieved of pressure,which greatly reduces the outstanding danger.Figure:[20]Table:[15]Reference:[68]...