Study on Fracture Behavior of Directly Covered Thick Hard Roof Based on Bearing Capacity of Supports

Mine pressure at the working face is severe due to it being directly covered by a thick hard roof. To further investigate technology of controlling mine roof, upper 13,121 in Gubei Huainan mining area was used as engineering background, and similar simulation experiments, mechanical analysis, numerical simulation, applications were obtain structure pre-cracked cut roof falling body, well establishing model hydraulic brace support resistance direct covering. The results combined with 20 m step top cutting showed that cantilever length plate shortened 25.61%, stress concentration reduced 31.74%, level 26.59–28.38%, destroying integrity rock body. According field monitoring data face’s initial periodic reduced, average dynamic load coefficients 1.43 1.33, respectively, small dispersion coefficient bracket. regulated, chosen equipment, conjunction scheme, can meet roof’s needs.