高应力软岩复合顶板回采巷道全锚索支护技术研究

Full anchor cable supporting technology of roadway with high stress and soft strata composite roof

针对赵庄煤矿回采巷道地应力高、软岩复合顶板、断面大以及回采期间巷道变形大等特点,提出了全断面高预紧力锚索支护技术。利用室内实验测试、现场测试、钻孔窥视方法,明确了3号煤层地应力和巷道顶板岩层属性、结构特性及煤岩体的物理力学特性,采用数值模拟方法确定了锚索支护参数,并进行了现场工业试验。结果表明:赵庄煤矿3号煤层最大埋深超过850m,最大和最小水平地应力侧压力系数为1.33和0.58,为典型的高应力煤层;3号煤层直接顶为泥岩和砂岩互层,裂隙较发育,岩体强度较低,为典型的软岩复合顶板;高预紧力全锚索支护技术能较好地控制回采巷道的围岩变形,关键区域通过及时施加补强锚索及注浆加固措施后,二次复用工作面巷道基本不需二次返修,保证了工作面的安全高效回采。

Aiming at the high ground stress, soft rock composite roof, large section and large roadway deformation during mining in Zhaozhuang Coal Mine, a full section high-pretension anchor cable support technology is proposed. Using indoor experimental tests, field tests, and borehole peeping methods, the ground stress of the No.3 coal seam and the properties and structural characteristics of the roadway roof rock layer and the mechanical characteristics of the coal and rock masses are clarified. The supporting parameters of anchor cable are determined by numerical simulation, and the field industrial test is carried out. The results show that the maximum depth of No.3 coal seam is over 850 m, and the lateral pressure coefficients of the maximum and minimum horizontal ground stress are 1.33 and 0.58, which is a typical high-stress coal seam. The immediate roof of No.3 coal seam is interbedded mudstone and sandstone, with relatively developed fractures and low rock mass strength. It is a typical soft rock composite roof. High pretension full anchor cable support technology can better control the surrounding rock deformation of roadway. After timely application of reinforcing anchor cable and grouting reinforcement measures in key areas, reusing of the gateway seldomly needs secondary repair, which ensures the safe and efficient mining of the working surface.