深部缓倾斜煤层切顶卸压自成巷应用研究

Application research on roof cutting and pressure relief self-formingroadway in deep gently inclined coal seam

针对林盛煤矿-780 m埋深、平均15°深部缓倾斜煤层地质条件,现场围岩非对称大变形支护难问题,采用理论计算,得出切顶高度、切顶角度以及恒阻大变形锚索支护等关键参数,并通过数值模拟和现场爆破试验优化了林盛煤矿1221运输巷切顶卸压自成巷工艺切缝深度8.0 m,切缝角度75°,封孔长度3.0 m,孔间距500 mm,装药结构为3+3+2+1的参数设计值,随后在林盛煤矿1221运输巷进行了工业性现场试验,矿压监测数据结果表明,在滞后工作面170 m左右巷道围岩变形基本趋于稳定,顶板最大下沉量165 mm,底鼓量38 mm,这与FLAC 3D数值模拟结果接近,证明了切顶卸压理论的正确性。留巷后巷道变形小,现场巷道围岩完整、无破坏现象,该试验深部缓倾斜煤层的成功应用可为切顶卸压自动成巷技术的进一步推广应用提供一定的借鉴。

In view of the geological conditions of-780 m buried depth,deep gently inclined coal seam at an average of 15°and the difficulty of asymmetric large deformation supporting of surrounding rock in Linsheng Coal Mine,the key parameters such as roof cutting height,roof cutting angle and constant resistance large deformation anchor cable supporting were obtained by theoretical calculation.Through numerical simulation and field blasting test,the design parameters of slit depth of 8.0 m,slit angle of 75°,hole sealing length of 3.0 m,hole spacing of 500 mm,and charging structure of 3+3+2+1 were optimized for No.1221 transport roadway in Linsheng Coal Mine.The results of mine pressure monitoring data indicate that the deformation of roadway surrounding rock basically tended to be stable when the lag working face was about 170 m,the maximum roof subsidence was 165 mm,and the floor heave was 38 mm,which was close to the numerical simulation results of FLAC 3D,which proved the correctness of the roof cutting and pressure relief theory.After gob-side entry retaining,the roadway deformation was small,the surrounding rock of the on-site roadway was intact,and there was no failure phenomenon.The successful application of the deep gently inclined coal seam in this test can provide certain reference for the further popularization and application of the automatic roadway formation technology by roof cutting and pressure relief.