高瓦斯综放开采覆岩导气裂隙带高度演化规律研究

Study on Height Evolution Law of Gas Conducting Fracture Zone in Overburden Strata in Fully Mechanized Caving Mining with High Gas

为探究高瓦斯厚煤层综放开采覆岩裂隙带高度演化规律,以主焦煤矿2303综放工作面为研究背景,通过正交试验研究了采厚、硬岩比例系数、煤层倾角、采深等因素对综放面导气裂隙带发育高度的影响特征,总结了各因素与导气裂隙带高度之间的关联性。通过UDEC软件模拟了综放面"两带"覆岩运移特征,模拟结果为:工作面充分采动时垮落带高度为21.7 m,裂隙带高度为45.0 m,台阶下沉现象明显。采用钻孔窥视仪对2303工作面"两带"进行探测,对比采动前后的覆岩裂隙情况可得:垮落带高度为20.7 m,裂隙带高度为44.3 m,与数值模拟结果一致。

In order to explore the height evolution law of gas conducting fracture zone in overburden strata in fully mechanized caving mining with high gas and thick coal seam, 2303 fully mechanized caving face in Zhujiao Coal Mine was taken as the research background. The influence characteristics of mining thickness, hard rock proportion coefficient, coal seam dip angle, mining depth and other factors on the development height of gas conducting fracture zone in fully mechanized caving mining were studied by orthogonal tests, and the relationship between each factor and the height of gas conducting fracture zone was summarized. The migration characteristics of overburden strata in "two zones" of fully mechanized caving face were simulated by UDEC software. The simulation results were as follows. When the working face is fully mined, the height of caving zone is 21.7 m, the height of fracture zone is 45.0 m, and the step subsidence phenomenon is obvious. The "two zones" of 2303 working face were detected by borehole peeper, and the overlying rock fractures before and after mining were compared. It is found that the height of caving zone is 20.7 m, and the height of fracture zone is 44.3 m, which are consistent with the numerical simulation results.