南屯煤矿深部沿空巷道耦合支护技术

Coupling support technology for gob-side entry at depth in Nantun Coal Mine

通过研究,确定了南屯煤矿九采区93上02综放工作面沿空回采巷道围岩为高应力节理化复合型(HJ型)软岩,根据巷道围岩变形力学机制及其转化对策,确定了锚网索耦合支护设计方案,即采用破底板掘进和超前支护优化围岩结构,采用直墙圆拱形巷道断面优化围岩受力状态,锚杆为直径22 mm,长2 500 mm的螺纹钢锚杆,间排距800 mm×500 mm,配合钢筋网及复合托盘,锚索长度为6 800 mm,排距2 000 mm。工程应用表明,巷道掘进期间围岩基本没有变形,工作面回采期间,顶底板变形量累计456 mm,两帮相对移近量累计518 mm,能够实现深部松软厚煤层沿空巷道围岩稳定性的有效控制,为工作面的安全高效生产创造了条件。

The surrounding rock of the gob-side entry of 93up02 coal mining face at Nantun Coal Mine appears to be high stressed joint complex soft rock. Based on the multiple deformation mechanics mechanism and transforming countermeasure of the surrounding rock, the design of bolt-mesh -anchor coupling support is suggested in the paper. It is to say that fore-poling supporting and floor-dinting are used to reinforce surrounding rock structure, and vertical wall semi-circular arch type of roadway are used to optimize the stress state of surrounding rock. Detailedly, the bolts parameters are twisted steel bolts of 22 mm in diameter, 2500mm in length, 800×500mm of separation-array pitch and fit bar-mat reinforcement and compound pallet. The anchor parameters are 6800mm in length, 2000mm in array pitch. The engineering application results show that a little deformation occurred in period of tunneling, and 456mm displacement of roof-to-floor and 518mm displacement of two walls occurred in period of mining, which indicates that the technology can control the deformation of the gob-side entry.