迎回采面沿空掘巷围岩控制技术实践

Practices on surrounding rock control technology of gateway driving along goaf towards to coal mining face

迎回采面沿空掘巷要全程经历毗邻区段回采后采空区侧向老顶断裂、回转、触矸的结构调整造成的动压影响,巷道变形较大。采用FLAC2D对巷道围岩垂直应力进行数值计算,发现其与沿稳定采空区边缘沿空掘巷垂直应力分布有显著差异,前者峰值点即弹塑性交界处离采空区距离更远。针对迎回采面沿空掘巷围岩变形特点,提出了围岩控制原理:合理选取煤柱宽度;采用高强度、大延伸率锚杆支护围岩;采用预应力对穿锚索、注浆加固窄煤柱。并且在利民煤矿进行了工程实践,取得了良好效果。

The gateway driving along the goaf towards to the coal mining face to be co ntiguous to other coal mining blocks was in the full procedure influenced by the dynamics occurred by the side main roof broken, rotary and touching coal reject structure adjusted in the goaf after coal mining. The gateway was high in deformation. The FLAC^2D was applied to have a numerical calculation on the vertical stress of the surrounding rocks of the gateway. It was found that there was an obvious difference in the vertical stress distributions of the gateway driving along the gateway surrounding rock and along the stable goat＂ boundary. The peak value point in the surrounding i. e. the elastic - plastic junction point would have a longer distance to the goaf. According to the deformation features of the surrounding rocks in the gateway driving along the goaf towards to the coal mining face, the control principle of the surrounding rock was provided with the rational selected coal pillar width, the high strength and longer extension rate bolt to support the surrounding and the pre - stressed cross anchor and grouting reinforcement for coal pillars. Good results were obtained from the practices in Limin Mine.