特厚煤层综放开采沿空掘巷窄煤柱围岩控制

Ground control of narrow coal pillar in gob side entry driving with fully mechanized top coal caving mining in extra-thick coal seam

针对某矿特厚煤层综放开采沿空掘巷宽煤柱护巷时带来的巷道变形量大,煤炭损失严重等问题,提出了窄煤柱护巷技术。以该矿8305工作面为工程背景,结合内外应力场理论和极限平衡区理论,得出基本顶断裂线位置距采空区为3 m,并最终确定窄煤柱宽度为6 m。基于对特厚煤层窄煤柱护巷围岩控制难点分析,提出了顶板以高强高预应力锚杆支护系统、组合锚索支护系统和多锚索-钢带桁架系统的强力联合支护技术,煤柱帮采用强力锚杆支护系统和喷浆加固的围岩控制技术,以及实体煤帮钻孔卸压处理和强力锚杆、锚索支护系统对特厚煤层沿空掘巷围岩稳定性的控制。现场实践表明,5305巷道围岩控制效果良好,能够实现对特厚煤层沿空掘巷围岩稳定性的控制。

In view of the problems of large roadway deformation and serious coal loss caused by gob side entry driving with wide coal pillar in fully mechanized top coal caving mining of extra-thick coal seam in Tongxin Mine,this paper puts forward the technology of narrow coal pillar roadway protection.Taking 8305 working face of Tongxin Coal Mine as engineering background,combined with internal and external stress field theory and limit equilibrium zone theory,it is concluded that the distance between the basic roof fracture line and the goaf is 3 m,and the narrow coal pillar width is 6 m.Based on the analysis of the difficulties in ground control of narrow coal pillar roadway in extrathick coal seam,the paper puts forward the strong combined support technology of roof with high strength and high prestress bolt support system,combined anchor cable support system and multi anchor cable steel belt truss system,surrounding rock control technology of strong bolt support system and shotcrete reinforcement for coal pillar side,as well as borehole pressure relief treatment of solid coal slope and support of strong bolt and anchor cable.The system controls the surrounding rock stability of roadway driving along goaf in the extra-thick coal seam.The field practice shows that the control effect of 5305 roadway surrounding rock is good,which can realize the control of surrounding rock stability of roadway driving along goaf in the extra-thick coal seam.