强采动大断面沿空煤巷围岩非对称控制研究

Study on asymmetric control of large section gob-side coal entry influenced by strong mining

针对剧烈采动下大断面沿空煤巷围岩破坏突出的难题,以王家岭矿20321沿空煤巷为研究对象,综合钻孔窥视监测、结构力学分析、数值模拟研究以及现场工业性试验等方法,探究大断面沿空煤巷采动影响下非对称矿压显现的规律。结果表明:典型沿空煤巷围岩破坏具有明显的不对称性,顶板结构不对称是围岩非对称破坏的直接诱因;实测基本顶断裂位置始于巷道上方距煤柱1.1 m处,并斜向采空侧延伸;沿空煤巷围岩收敛呈斜"一"字形,沿空煤巷两侧载荷的差异性,促使巷道围岩呈不对称破坏发展趋势。提出高预应力锚杆索桁架非对称控制技术,有效控制了典型沿空煤巷围岩变形,丰富了大断面沿空煤巷围岩控制理论及实践经验。

To solve the problem of severe damage in the large section fragmentized gob-side entry, with gob-side entry 20321 in Wangjialing Mine as the background, the failure law and the mechanism of surrounding rock were investigated through combined methods of borehole observation,laboratory tests, mechanics analysis, and numerical simulation, etc. The results have shown that surrounding rock damage in the typical gob-side entry is obviously asymmetric, and the asymmetric roof structure is the direct cause of the asymmetric damage; the broken location of the main roof starts 1.1 m away from the pillar, and extends to the gob-side; the surrounding rock deformation in the gob-side roadway develops in a ＂diagonal line＂; the load form and quantity of coal roadway are different which accelerates the asymmetric damage of the surrounding rock. The asymmetrical control technology for high pre-stressing trusses and cables proposed can control the surrounding rock deformation efficiently and enrich surrounding rock control theory and practice.