近距离煤层预掘巷道应力转移技术

Stress Transfer Technique for Close Distance Coal Seam Pre-excavation Roadway

针对受近距离煤层重复采动影响,常规支护体系无法控制巷道围岩变形的问题,为控制巷道变形,提出在工作面停采线附近预掘巷道并进行深孔爆破的方案。通过对预掘巷道施行"锚-让"一体支护体系,保证了卸压巷道围岩稳定,利用深孔爆破对预掘巷道顶板进行强制切顶,使卸压巷能够充分卸压,实现应力转移。采动应力在线系统监测结果表明:采动附加应力场向前传播的距离小于15 m,利用预掘卸压巷及深孔爆破对卸压巷道顶板进行强制切顶实现应力转移保护下山群巷道是可行的。

In view of the problem that the conventional support system cannot control the deformation of roadway surrounding rock due to the influence of repeated mining in close coal seams,to control the deformation of roadway,a scheme of pre-excavation of roadway near stop-mining line of working face and deep-hole blasting is proposed.Through the implementation of'anchor-yield'integrated support system for the pre-excavation roadway,the surrounding rock of the pressure relief roadway is guaranteed to be stable,and the roof of the pre-excavation roadway is forced to be cut by deep hole blasting,so that the pressure relief roadway can be fully relieved and the stress transfer can be realized.The monitoring results of online mining stress system show that the distance of the additional stress field propagated forward by mining is less than 15 m,and it is feasible to use pre-excavation pressure relief roadway and deep-hole blasting to carry out forced roof cutting on the roof of pressure relief roadway to realize stress transfer protection for the down-hill group roadway.