定向预裂爆破技术在小煤柱沿空掘巷中的应用研究

Research on the Application of Directional Presplitting Blasting Technology in Small Coal Pillar Tunneling Along the Gob

针对小煤柱沿空掘巷期间巷道压力较大、煤柱应力集中而造成小煤柱巷道围岩控制困难的问题,以青洼煤矿为工程地质背景,提出了定向预裂爆破技术,理论研究了定向预裂爆破技术技术原理,并确定了爆破关键工艺参数,最后在现场进行了工程试验。结果表明,采用该技术后,能够有效切断采空区、煤柱上覆基本顶岩层间的应力联系,采空区侧向压力峰值减小且向深部转移;小煤柱巷道掘进期间顶底板收缩量最大为424 mm,两帮收缩量最大为160 mm,巷道围岩变形可控,说明实施切顶卸压后改善了小煤柱巷道的应力环境。通过此次试验,确保了小煤柱工作面安全生产,也为相似条件下的工程实施提供了一定技术参考。

Based on the problem of difficulty in controlling the surrounding rock of small coal pillar tunnels caused by high pressure and concentrated stress during the excavation of small coal pillar tunnels along the goaf,the shaped energy tube directional pre-splitting blasting technology was proposed with the engineering geological background of Qingwa Coal Mine.The technical principle of directional pre-splitting blasting technology was theoretically studied,and key blasting process parameters were determined.Finally,engineering experiments were conducted on-site.The results show that using this technology can effectively cut off the stress connection between the goaf and the basic roof of the coal pillar,reduce the peak lateral support pressure in the goaf,and transfer to the deep.During the excavation of the small coal pillar tunnel,the displacement of the top and bottom plates was 424 mm,and the displacement of the two sides was 160 mm.The deformation of the surrounding rock of the tunnel was controllable,indicating that the stress environment of the small coal pillar tunnel was improved after the implementation of roof cutting and pressure relief.This ensures the safe production of the small coal pillar working face and provides a certain technical reference for engineering implementation under similar conditions.