祁东矿巨厚坚硬顶板切顶无煤柱开采技术应用研究

Study on application of cutting roof without pillar mining technology with thick and hard roof in Qidong Mine

为解决当前煤矿开采过程中存在煤炭采出率低、留煤柱开采引起应力集中、巷道围岩控制难等问题,以祁东煤矿7135工作面为工程背景,提出切顶沿空留巷技术。通过对巷道围岩运动特征和留巷技术原理的研究分析,确定切顶留巷关键技术参数,并在现场进行了工程应用。结果表明,采用高强预应力锚索补强顶板、垛式支架支撑顶板及可伸缩U型钢挡矸防护等联合支护体系,实体煤帮平均变形量达到166 mm,采空区帮平均变形量达到237 mm,顶板平均下沉量达到163 mm,平均底鼓量208 mm,留巷变形满足安全生产要求。

In order to solve the problems of low coal recovery rate,stress concentration caused by coal pillar mining,and difficult control of surrounding rock of roadway in the current coal mining process,taking 7135 working face of Qidong Coal Mine as the research background,the paper put forward the mining technology without coal pillar along gob-side entry retaining with roof cutting and pressure relief.Based on the analysis of the movement characteristics of surrounding rock and the technical principle of gob-side entry retaining,the key technical parameters of gob-side entry retaining were formed,and the industrial test is carried out in the field.The results show that the combined support system of high-strength prestressed anchor cable reinforcement roof,buttress support roof and extensible U-shaped steel gangue retaining protection is adopted;the average deformation of solid coal side is 166 mm,the average deformation of goaf side is 237 mm,the average subsidence of roof is 163 mm,and the average floor heave is 208 mm.The roadway retaining deformation meets the requirements of safety production.