整合矿井沿空巷道围岩破坏机制及支护优化

针对整合矿井巷道掘进揭露采空区时煤柱宽度变小所导致的巷道持续变形、原有支护失效的围岩控制难题,分析了不同宽度煤柱条件下沿空巷道的顶板结构及应力场分布状态,得出支承压力峰值位置随煤柱宽度的变化规律,巷道原有支护失效的主要原因为围岩的应力环境差及支护强度低。通过数值软件模拟了不同巷道断面的围岩应力分布状态,提出采用U型钢可伸缩拱形支架进行原有矩形巷道断面的优化,并结合水泥背板及充填缓冲材料构建巷道空间。近两年的监测结果表明,错车硐室2表面位移值为0,巷道喷浆完好,未发生开裂剥落等破坏现象,表明采用U型钢可伸缩拱形支架进行揭露采空区段巷道的支护优化是合理可行的,为类似地质条件下的巷道支护提供了技术借鉴。

Failure Mechanism of Roadway Surrounding Rock in integration mine and Its Support Optimization

Aiming at the surrounding rock control problems such as continuous deformation of roadway and failure of original support cause by the width decrease of coal pillar when expose the gob during roadway driving in integration mine, the roof structure and the distribution of stress field of the gob side entry with different width coal pillar were analyzed, and the variation of the position of the peak abutment pressure with the width of coal pillar were understood. The main reason for the failure of the original supporting of roadway is that the stress environment of surrounding rock is poor and the supporting strength is low. Furthermore, the stress distribution of surrounding rock in different roadway sections was analyzed through numerical simulation, and the U type steel telescopic arch support was proposed to optimize the section of the original rectangular tunnel. The roadway space was constructed combined with cement backboard and filling cushion material. The monitoring results show that in recent two years the surface displacement value is 0, and the roadway shotcrete stay intact. The monitoring results shows that it is reasonable and feasible to use the U type steel telescopic arch support for the optimization of roadway support during exposed gob section, which provides technical reference for tunnel support under similar geological conditions.