厚煤层沿空掘巷围岩支护技术研究

Study on supporting technology of road driving along next goaf based on Three Soft coal seam

为解决采掘接续紧张问题,潞宁煤业115工作面回风巷采用沿不稳定采空区跟随回采面掘巷。在开展地应力、煤岩体强度及钻孔结构全面测试的基础上,基于一次支护原则提出了"高预应力锚杆锚索—钢护板"联合支护设计方案,并对煤柱侧帮进行短锚索补强。现场监测结果表明,测站距掘进头达400 m时锚杆锚索工作载荷开始稳定,锚杆工作载荷最大值稳定在135 kN,锚索工作载荷最大值稳定在243 kN,锚杆锚索工作载荷均处于屈服载荷合理范围内。掘巷阶段两帮最大回缩量182 mm,顶板最大下沉量110 mm,底板变形不明显。回采阶段超前巷道底鼓明显,最大底鼓量500 mm左右。研究成果可为类似采矿条件下沿空掘巷支护提供经验指导。

In order to solve the problem of mining and excavating tension,Luning colliery＇s 115 tail-entry laid along the unstable goaf with stope roadway excavation. On the basis of comprehensive test of crustal stress,coal rock mass strength and borehole structure,a combined supporting scheme were put forward with high pre-stressed bolt cable steel plate,and the short anchor rope reinforcement was applied to the side pillar of coal pillar. The monitoring results showed that the station from the head of 400 m bolt and cable load working load became stable,bolt stable value of 135 kN at the maximum working load,cable stable value of 243 kN in the maximum load,bolt and cable were both at a reasonable range of yield load. Heading stage two sides for max shrinkage of 182 mm,the roof maximum subsidence of 110 mm,floor deformation was not obvious. In the mining stage,the floor heave of the roadway was obvious,and the maximum heave amount was about 500 mm. The research results can provide experience guidance for the gob side entry driving under similar mining conditions.