关键词: 沿空留巷, 煤柱回收, 围岩控制, 重复采动

Abstract: The stability control of the surrounding rock of the goaf retaining roadway under the influence of repeated mining is an important guarantee for ensuring safe mining of the working face under the conditions of adopting the roadway layout technology. Especially, it is of great safety significance for the western mining area to achieve simultaneous mining between the coal body and the coal pillars between the working face and the remaining face when the original roadway layout technology of double roadway excavation is changed to the goaf retaining roadway technology. This article is based on the engineering background of the transformation of the roadway layout technology from the original double roadway excavation to the goaf retaining roadway during the simultaneous extraction of the coal body of the 12408 fully mechanized mining face and the remaining coal pillars between the 12407 working face in Ulan Mulun Coal Mine, Through a large amount of on-site measured data, the full life cycle failure characteristics of the surrounding rock of the goaf retaining roadway and its influencing factors of instability and deformation are summarized and analyzed; The FLac numerical simulation software was used to analyze the response mechanism of coal pillar recovery between faces to the instability of surrounding rock in the goaf retaining roadway, and multiple measures and techniques were proposed to solve the instability problem of surrounding rock in the remaining section of the 12408 external return air passage. The results indicate that the main factors leading to the instability of the surrounding rock of the retained roadway are the influence of secondary dynamic pressure superposition, the coupling effect of bedrock lithology characteristics and burial depth, and the irrational matching of tunnel section support strength and mining strength parameters; After adopting the coupling control technology system of reinforcement support, adding unit supports, and reasonable control of mining speed, the remaining section of 12408 working face has a top separation layer value of 70mm during the mining process, a maximum subsidence of 40mm on the roof, and a maximum displacement of 23mm on both sides. The overall change is small, and the deformation of the surrounding rock does not affect safe mining, and is within the controllable range.