定向预裂切顶沿空掘巷技术应用研究

为了解决九里山矿沿空掘巷巷道支护压力大、变形量大、支护困难、维修工程量大的问题，基于切顶卸压原理和定向预裂爆破技术，结合九里山矿15091回风巷顶板岩层情况，确定了预裂爆破的深度，采用了双缝定向预裂管有效控制爆破产生裂隙的方向，实现了定向爆破。制定了切顶沿空掘巷施工方案，确定了定向预裂爆破参数及沿空掘巷巷道支护形式与参数，并通过矿压观测，对沿空掘巷成巷效果进行了评价。研究结果表明:采用定向预裂切顶爆破后，成巷不稳定时间由30 d缩短到20 d，短时间内巷道进入稳定期；沿空掘巷巷道两帮移近量最大为326 mm，较未切顶巷道减少了112 mm；顶板最大移近量为135 mm，较未切顶巷道减少了80 mm，巷道变形量明显减少，巷道维修量也大幅减少，取得了较好的经济效果。

Application study on driving along gob technology with directional pre-splitting and roof-cutting

In order to solve the problems of large support pressure，large deformation，difficulty in support and large amount of maintenance work in the gob-side driving roadway of Jiulishan Mine，the depth of pre-splitting blasting is determined based on the principle of roof cutting and pressure relief and directional pre-splitting blasting technology，combined with the roof strata of 15091 return air roadway in Jiulishan Mine，and the direction of cracks produced by blasting is effectively controlled by double-slit directional pre-splitting pipe，thus realizing orientation blast.Therefore，the construction scheme of gob-side roadway with cutting roof is formulated，the parameters of directional pre-splitting blasting and the supporting forms and parameters of gob-side roadway are determined，and the effect of gob-side roadway is evaluated through rock pressure observation.The results show that after adopting directional pre-splitting roof-cutting blasting，the instability time of roadway is reduced from 30 days to 20 days，and the roadway enters a stable period in a short time；the maximum approximation of two sides of roadway along goaf is 326 mm，which is 112 mm less than that of roadway without roof-cutting；the maximum approximation of roof is 135 mm，which is 80 mm less than that of roadway without roof-cutting；the deformation of roadway is obviously reduced，and the maintenance of roadway is also greatly reduced，the technology has achieved good economic results.