Research on Deformation Mechanism and Control Technology of Floor Gas Extraction Roadway

Aiming at the problems of low reuse rate, continuation tension and others in traditional gas extraction roadways, taking the floor gas extraction roadway of the 7th coal seam in Xinji No.1 Mine as the engineering background, a "one roadway for multiple purposes" collaborative utilization technical system based on the full life cycle concept is proposed, through numerical simulation, the evolution laws of mining stress and surrounding rock damage are analyzed, on this basis, an asymmetric support scheme is designed to achieve local strengthening support in damaged areas, and the roadway stability is verified with the help of on-site monitoring. The research shows that this technology can achieve the transformation of roadway functions, significantly reducing the engineering quantity of excavation, and saving 25 million yuan in roadway excavation costs for only the 230703 working face; The advanced support stress of the working face tends to be stable after advancing for 150 m, with an influence range of 50 m, approximately, the stress is transmitted downwards to form a double concentration zone, that is, a new stress concentration zone appears on the non-exposed side below the goaf after pushing and mining exceeds 150 m; The monitoring results indicate that the changes in roof abscission layer, surface displacement, and anchor rod force-bearing are all within the safe range, which confirms the reliability of the optimized support scheme.