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

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.