上位煤层蹬空开采可行性理论研究与校验

Theoretical Study and Verification of the Feasibility of Top-coal Caving Mining

针对宝欣煤矿2号煤层遗煤蹬空开采的问题,根据勘探资料利用比值判别法、数理统计分析法、“三带”判别法以及围岩平衡法对3号煤层采空区上覆围岩性质进行了理论计算,结果显示2号煤层位于3号煤层回采后的裂隙带高度范围内。使用钻孔分段注水法进行了验证,注水最快流速达到0.065 m^(3)/min,说明3号煤层顶板结构不稳定、存在较多裂隙。由此判断2号煤层不适合蹬空开采。

In view of the problem of the abandoned coal in the second coal seam of Baoxin Coal Mine,the properties of the overlying surrounding rock in the goaf of the third coal seam were theoretically calculated by using the ratio discrimination method,mathematical statistical analysis method,"three zones"discrimination method and the surrounding rock balance method according to the exploration data,and the results showed that the second coal seam was within the height range of the fracture zone after the third coal seam was mined.It has been verified by using the borehole segmented water injection method,and the fastest flow rate of water injection reaches 0.065 m^(3)/min,indicating that the roof structure of No.3 coal seam is unstable and there are many cracks.Therefore,it is judged that the 2#coal seam is not suitable for goaf mining.