超远距离下组煤层超前开采覆岩应力及裂隙演化规律研究OA北大核心CSTPCD

In order to explore the influence of advanced mining of ultra-long distance lower group coal seam on overlying coal and rock strata in No.8 Mine of Pingdingshan Coal Company Limited,similar material simulation experiments were used to analyze the fracture and stress evolution law of overlying coal and rock strata in advanced mining of ultra-long distance lower group coal seam,and on-site verification.The experimental results show that under the condition of advanced mining of the coal seam in the ultra-long-distance lower formation,the fracture rate of the overlying coal seam shows a trend of first increasing and then stabilizing with the advancement of the working face,and the fracture development is the fastest when the working face is advanced from 187 m to 272 m.The advanced mining of the coal seam in the lower group of ultra-long-distance has a pressure relief effect on the overlying coal rock formation,but the lag distance of pressure relief is larger than that under conventional conditions.The pressure relief of the overlying rock formation is larger than that of the Wu group coal seam.Through on-site verification,it is found that with the advancement of the working face,the mine pressure first rises and then decreases and then stabilizes,and the working face area is divided into undisturbed area,stress concentration area,pressure relief area and stability area.The research conclusions can provide reference for the long-distance advanced mining of coal in the lower coal formation in the Pingdingshan coal mining area,the prevention and control of gas in the coal seam face of the upper group and the mining deployment of the working face in the mining area.