近距离煤层内错式开切眼合理错距的研究

为探究近距离煤层内错式开切眼水平错距的合理选取问题，以神东矿区某矿为工程研究背景，通过构建力学模型得到上覆煤层遗留停采煤层产生的附加应力对下方开切眼的应力解析解，采用数学分析得到下煤层的水平停采距离的合理范围，并运用FLAC3D数值模拟软件分析不同水平错距下切眼位置所处的应力环境，得到下煤层开切眼停采的水平距离为50 m时能够满足巷道布置要求。通过地质雷达进行开切眼巷道的围岩松动圈的测试，得到开切眼巷道松动圈的范围为3.1 m~3.8 m，切眼巷道左帮的破碎范围大于顶板，开切眼巷道围岩完整性较好。研究结果表明，下煤层内错式开切眼停采水平距离为50 m时，开切眼巷道能够满足工作面的正常回采。

A Reasonable Staggered Distance of Internally Staggered Open-Off Cuts in Close Coal Seams

A mine in the Shendong mining area was taken as the engineering research background to explore the reasonable selection of the staggered horizontal distance of staggered open-off cuts in close coal seams. A mechanical model was constructed to obtain the analytical solution of additional stress generated by the overlying coal seam and the remaining non-mining coal seam to the stress of lower open-off cuts. Mathematical analysis was used to obtain the reasonable range of the stopping-mining horizontal distance of the lower coal seam. Besides, FLAC3D numerical simulation software was used to analyze the stress environment of the lower open-off cut holes at different staggered horizontal distances. The roadway layout requirements could be met when the horizontal distance between the lower coal-seam opening and stopping mining was 50 m. The range of the broken rock zone of the roadway with open-off cuts was 3.1-3.8 m by testing that of surrounding rocks with the geological radar. The broken range of the left side of the roadway with open-off cuts was larger than that of the roof, and the surrounding rocks have good integrity. The results showed that the roadways could meet the normal mining of the working face when the stopping-mining horizontal distance of internally staggered open-off cuts in the lower coal seam was 50 m.