贺西煤矿三采区运输巷扩刷变形分析与控制

基于扩刷施工后大断面巷道围岩控制难题,以贺西煤矿4#煤层三采区运输巷扩刷施工为研究背景,理论分析了扩刷后大断面巷道围岩控制难点,采用FLAC3D软件模拟了运输巷扩刷前后围岩铅直应力与塑性区的分布与演化特征。结果显示:扩刷后巷道围岩铅直应力集中区及塑性区分布范围明显增大,巷道浅部围岩存在3.5m厚连续均匀分布的"塑性环"。据此,提出锚杆索+注浆+U型钢棚等联合支护技术,锚杆支护后在巷道浅部围岩形成厚度为1.6m的预应力拱形承载结构。试验表明:巷道顶底板与两帮最大移近量分别为218mm和165mm,扩刷后巷道围岩变形得到了有效控制。

Deformation analysis and control of expanding brush of haulage roadway of No.3 mining district in Hexi Coal Mine

Based on the control problems of surrounding rock of large-section roadway after the expansion, the expansion and construction of the haulage roadway in the third mining district of the No. 4 coal seam of Hexi Coal Mine is taken as the research background. The difficulty in controlling the surrounding rock of the large-section roadway after the expansion is theoretically analyzed. The distribution and evolution characteristics of vertical stress and plastic zone of surrounding rock before and after the expansion of haulage roadway are simulated by FLAC_3D. The results show that the distribution range of the vertical stress concentration zone and the plastic zone of the roadway after the expansion are obviously increased. There is a continuous and evenly distributed "plastic ring" of the thickness of 3.5 m in the surrounding rock of shallow roadway. Accordingly, the joint support technology of anchor cable grouting U-shaped steel shed is proposed. After the support of bolt, a prestressed arch-shaped bearing structure with a thickness of 1.6 m is formed in the surrounding rock of the shallow roadway. The tests show that the maximum displacement of the top and bottom of the roadway is 218 mm, while two gangs is 165 mm, and the deformation of the roadway after the expansion is effectively controlled.