大断面煤巷巷宽效应及支护技术

Support technology and width effect of large section coal roadway

针对煤巷宽度增加后的围岩控制难题,选取磁窑沟煤矿10104轨道巷为研究对象,采用FLAC3D模拟研究了巷宽对围岩的影响,结果表明:顶、底、两帮塑性区呈"半椭圆"状分布,随巷宽增加,塑性区面积和深度增加速率为顶板大于两帮大于底板;顶、底、两帮深部变形呈"负指数"关系向深部降低;同一围岩深度,表面变形量及变形增加量为顶板大于两帮大于底板;帮浅部支承压力随巷宽增加而降低,且支承压力峰值向深部转移。根据桁架锚索、高强高预紧力锚杆支护特点,提出高强高预紧力锚杆与桁架锚索联合支护技术,工程实践结果:帮移近量97mm,顶底板移近量127mm,顶板离层量3mm。

Aiming at the surrounding rock control difficulty with the increasing width of coal roadway. The influence of roadway width on surrounding rock is analyzed with FLAC^3D, based on the background of No. 10104 rail roadway in Ciyaogou Coal Mine. The results show that, plastic zone areas in the roof, floor and two ribs were all distributes as semi - ellipse, and the increasing rate of plastic zone areas and depth with the width increasing can he ranked as： roof 〉 two ribs 〉 floor; the displacement in roof, floor and two ribs decreases negative exponentially as the depth increases; under the same surrounding rock depth, the surface displacement and displacement increment can be ranked as ： roof 〉 two ribs 〉 floor; along with the increasing roadway width, the abutment pressure in shallow part of the rib decreases and the peak abutment pressure move to the deep. A combined support technology is proposed applying high strength and high pre - stress bolt support and trusscable support, based on the support characteristics. According to engineering practice, the two - rib convergence is 97mm, the roof-to -floor convergence is 127mm and the roof separation is 3mm.