邻空厚煤层高强度开采工作面煤壁失稳机理

Instability mechanism of rib in high-strength mining face beside gob with thick coal seam

针对西部矿区高产高效厚煤层工作面邻空开采时煤壁大面积失稳的问题,在现场调研的基础上,通过工作面液压支架工作阻力分析、顶板悬顶钻孔探测相结合的方法,研究了邻空高强度开采工作面煤壁失稳机理。结果表明:①工作面推进到相邻采空区附近,采空区侧煤层顶板失去支撑是引起煤壁失稳的主要原因;②工作面邻空开采时,靠近采空区一侧的液压支架工作阻力升高,且工作阻力与煤壁片帮次数呈正相关;③工作面邻空开采,采空区侧煤柱上方存在悬顶,煤柱进入塑性阶段失去支承能力使得侧向支承压力峰值移向煤壁,从而引起煤壁失稳。研究成果可为西部矿区邻空开采生产设计、矿压理论研究提供借鉴。

In view of the problem of large-area instability of rib when the working face of the high-yield and high-efficiency thick coal seam is mining beside the gob in the western mining area,based on site investigation,the mechanism of rib instability in the high-strength mining face was studied through the method of combining the working resistance analysis of the working face with the roof overhang drilling detection.The results show that:①the working face advances to the vicinity of the adjacent gob,and the loss of support on the roof of the side of the gob is the main reason for the instability of the rib.②When the working face is advanced to the area near the gob,the working resistance of hydraulic support in adjacent gob obviously become higher;and the working resistance is positively correlated with the num-ber of rib spalling.③When mining at the working face adjacent to the gob,there is a suspended roof above the side coal pillars in the gob,and the coal pillars lose their supporting capacity in the plastic stage,causing the peak lateral supporting pressure to move to the coal wall,thus the coal wall loses its stability.The research results can provide reference for mining production design and mine pressure theory research in western mining areas.