切顶留巷技术工程应用研究

Study on engineering application of gob-side entry retaining technology

山西某煤矿125220胶运顺槽实施切顶留巷技术,为研究该技术工程应用问题,对留巷围岩取样进行了力学参数测定实验,采用FLAC^(3D)进行了不同切缝深度、不同切缝角度数值模拟研究。最终确定切缝深度10 m,切缝角度10°最佳,切缝孔孔间距0.6 m、孔深10 m、装药5 m、封孔3 m、10个孔一组同时爆破。回采推进期间,切顶留巷巷道顶板深部最大位移量176 mm、浅部最大位移量78 mm,在留巷段使用的单体液压支架产生应力波动,最大值为42 MPa,支护措施安全可靠。

The gob-side entry retaining technology is adopted for the 125220 belt conveyor entry of a coal mine in Shanxi Province,in order to study the engineering application of the technology,the entry surrounding rock is sampled to carry out a measuring test of mechanical parameters,followed by a FLAC^(3D) based numerical simulation study by different cutting depths and angles.Finally,it is determined that the optimal cutting depth is 10 m,the cutting angle is 10°,the spacing of cutting holes is 0.6 m,the hole depth is 10 m,the charging depth is 5 m,the hole sealing is 3 m,and a group of 10 holes is blasted at the same time.During the advance of stopping,the maximum displacement of the entry roof in the deep part is 176 mm and in the shallow part is 78 mm.The single hydraulic support used in the entry retaining section produces stress fluctuation,with the maximum value of 42 MPa.The support measures are safe and reliable.