Study on Stress Distribution Laws of Crossing and Mining Open-off Cut

Taking ascending mining of outward staggered arrangement in Qiuci A6-103 working face as the background, the stress distribution laws of coal seam, roof and floor in the process of crossing and mining lower open-off cut was studied by numerical simulation. The results showed that the vertical stress of coal seam and roof and floor reached the maximum when the A6-103 working face crossed and mined the lower open-off cut of 170 m to 240 m and the working face was 10 m from the open-off cut. The leading influence range of coal body on solid coal side is about 50 m, and the advanced influence range of goaf side coal is about 20 m. The leading influence range of roof is about 40 m, and that of floor is about 25 m. The peak stress on the side of goaf at 8 m of roof is 56% lower than that of the coal side. The peak stress on the side of goaf in the depth of 2 m of the bottom plate decreased by 26.6% compared with that of the solid coal; during the period of crossing and mining open-off cut 190 m to 230 m, the increase rate of support resistance was mainly distributed between 0.5 MPa/min and 1.4 MPa/min, which was significantly higher than that in other areas. The results show that the stress distribution laws of the numerical model study is basically consistent with the stress distribution law measured in the field.