小庄煤矿巷道围岩松动圈裂隙结构特征分析

Analysis on fracture structure characteristics of loose zone of roadway surrounding rock in Xiaozhuang Coal Mine

针对本煤层抽采钻孔封孔深度问题,以小庄煤矿40205工作面泄水巷、40307运顺巷道和40309回顺巷道为工程背景,采用钻孔成像仪进行钻孔窥视及理论分析,研究了巷道围岩松动圈的裂隙结构特征。结果表明,工作面巷道围岩内裂隙发育程度及分布规律受采动影响较大,受采动影响区域较未受采动影响区域裂隙更为发育,裂纹更多,孔壁平滑区域更为深入;测定了工作面巷道围岩松动圈范围,未受采动影响区域的巷道松动圈范围4.00~4.50 m,受采动影响区域的巷道松动圈范围扩大到9 m左右。基于此,得到了本煤层抽采钻孔封孔深度的建议范围,对提高本煤层瓦斯抽采效率具有重要意义。

Aiming at the problem of the sealing depth of gas extraction boreholes in the coal seam, taking the 40205 drainage roadway, 40307 transportation roadway and 40309 return roadway of Xiaozhuang Coal Mine as the engineering background, the fracture structure characteristics of loose circle of roadway surrounding rock are researched through borehole peeping with borehole imager.The results show that the development degree and distribution law of fractures in the roadway surrounding rock of the working face are greatly affected by mining, the fractures in the area affected by mining are more developed than those in the unaffected area, there are more cracks, and the area with smooth hole-wall is deeper.The measurement of the range of roadway surrounding rock loose zone in the working face shows that the range of roadway loose zone in the area not affected by mining is 4.00~4.50 m, and the range of roadway loose zone in the area affected by mining is expanded to about 9 m.Through the research, the recommended range of sealing depth of gas extraction boreholes in the coal seam is obtained, which is of great significance to improve the gas extraction efficiency.