西部矿区上行开采松软破碎围岩回采巷道支护技术
Roadway Support Technology for Upward Mining of Soft and Broken Surrounding Rocks in Western Mining Area
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摘要: 秦华煤矿位于库尔勒市焉耆盆地西南缘,其主采煤层群间距近、层间岩层松软破碎,受上行开采 影响,上部煤层回采巷道支护难度较大。建立FLAC3D数值模型,分析下伏煤层回采支承压力对上部煤层 作用与影响区域,确定上行开采条件下回采巷道合理位置,优化巷道支护方案。研究结果表明,秦华煤矿 上行开采条件下上覆煤层回采巷道应内错式布置,内错4~8m 为宜。巷道顶部采用全锚索支护时,巷道 围岩应力集中系数、塑性破坏范围均较小,促使巷道拱顶区域巷周应力峰值向围岩深处转移,改善巷道浅 部围岩应力环境。巷道拱部采用全锚索支护,与单纯锚杆-锚索支护结构相比,具有锚固岩层范围广、支护 强度大、支护效果好的优点,在松散破碎围岩下巷道的支护体系内,巷道顶板岩层应建立全锚索支护体系。Abstract: QinHua Coal Mine is located at the southwest edge of Yanqi Basin, Korla City,which main coal seam group spacing is close, and the interlayer rock strata is soft and broken. Affected by the upward mining, it is difficult to support the mining roadway of the upper coal seam. The FLAC3D numerical model is established to analyze the effect and influence area of the lower coal seam recovery support pressure on the upper coal seam, determine the reasonable position of the mining roadway under the upward mining conditions, and optimize the roadway support scheme. The study shows that the upper cover coal seam mining roadway of Qinhua coal mine should be arranged in the internal wrong type, and the internal error of 4-8m is appropriate. When the full anchor cable is supported on the top of the roadway, the stress concentration coefficient and plastic damage range of the roadway are small, which promotes the peripheral stress peak of the roadway arch area to the depth of the surrounding rock and improves the stress environment of the shallow surrounding rock of the roadway. The roadway arch adopts full anchor cable support. Compared with the simple bolt-anchor cable support structure, it has the advantages of wide range, large support strength and good support effect. In the support system of the roadway under the loose broken surrounding rock, a full anchor cable support system should be established in the roof rock layer of the roadway.