大采高工作面复杂应力扰动下切顶卸压沿空留巷技术

针对寺河煤矿3^#煤大采高工作面复杂应力扰动下留巷难度大、临空侧复用巷道围岩变形严重等问题,采用水力压裂技术对巷道顶板关键层位进行定向预裂,将临空侧煤柱上方悬臂梁切落,以减小悬臂梁上覆荷载及回转变形力,切断或大大削弱岩梁传递到护巷煤柱和留设巷道内的荷载,从根本上改善巷道的力学环境。结果表明:水力压裂法切顶卸压技术的应用,有效改善了留设巷道围岩应力状态,控制了留设巷道围岩变形,避免了巷道二次甚至多次返修,降低了巷道的支护难度和支护成本。

The Technique of Cutting Top Unloading along Empty Lane under Complex Stress Disturbance of Large Mining High Face

In view of the difficulty to leave the roadway under complex stress disturbance for 3 # coal mining height working face in Sihe mine, and the serious deformation of surrounding rock of roadway multiplexing at the airport side, Hydraulic fracturing technology is adopted to conduct directional pre-cracking on key strata of roadway roof, and the cantilever beam above the coal pillar on the face side of the roadway is cut off, so as to reduce the overhanging load of the cantilever beam and the rotary deformation force, so as to cut off or greatly weaken the load transferred from the rock beam to the coal pillar protecting the roadway and the remaining roadway, and fundamentally improve the mechanical environment of the roadway. The results show that the application of hydraulic fracturing in cutting off the top of the roadway can effectively improve the stress state of the surrounding rock, control the deformation of the surrounding rock, avoid the secondary or multiple repair of the roadway, and reduce the support difficulty and cost of the roadway.