深部高应力煤巷围岩塑性破坏特征及支护对策研究

    Study on the characteristics of plastic failure and supporting countermeasures of the surrounding rock of deep high-stress coal roadway

    • 摘要: 针对深部煤巷掘进后围岩变形大、支护困难等问题,以朱集西11101运输顺槽为研究对象,理论计算了巷道掘进后的围岩塑性破坏半径,提出以“高预紧力锚杆(索)+金属网”为核心的支护方案,进而模拟分析了六种不同顶板支护密度下的巷道围岩变形特征及应力分布规律,筛选出了最优支护方案进行现场实践,结果表明:增加锚杆数量、减小锚杆排距虽均可提高围岩控制效果,但在保障巷道围岩控制效果的同时应考虑到经济效益,最终选择顶板锚杆间排距为800 mm×700 mm、锚索间排距为1 800 mm×1 600 mm、两帮锚杆间排距为800 mm×800 mm的最优支护方案;方案3同其他支护相比较,顶板最大下沉量从72 mm减小至60 mm,减小了16.67%,最大底鼓量从150 mm减小到90 mm,减小了40.00%,水平应力峰值从36.73 MPa减小到31.20 MPa,减小了15.06%,支护方案有效地降低了围岩应力峰值,减小了巷道围岩变形情况,验证了支护方案的可靠性;试验段监测结果表明方案3支护效果良好,在监测期内巷道顶板累计下沉量为61 mm,累计底鼓量为102 mm,两帮累计移进量为156 mm,有效地遏制巷道围岩的变形破坏。

       

      Abstract: Addressing issues such as significant deformation of surrounding rock and difficulties in support after deep coal roadway excavation, this paper takes the transportation roadway of the Zhujixi 11101 working face as its research object. The plastic deformation radius of the surrounding rock after roadway excavation is theoretically calculated, and a support scheme centered on “high preload anchor bolts (cables) + metal mesh” is proposed. Subsequently, the deformation characteristics and stress distribution patterns of the surrounding rock under six different roof support densities are simulated and analyzed, and the optimal support scheme is selected for field implementation. The results show that while increasing the number of anchor bolts and reducing the spacing between anchor bolts can both improve rock mass control effectiveness, economic benefits should also be considered while ensuring roadway rock mass control effectiveness. The optimal support scheme selected has a spacing of 800 mm × 700 mm between roof anchor bolts, a spacing of 1 800 mm and 1 600 mm between anchor cables, and a spacing of 800 mm and 800 mm between side anchor bolts. Compared with other support schemes, scheme 3 reduces the maximum roof settlement from 72 mm to 60 mm, a decrease of 16.67%, the maximum floor bulge decreases from 150 mm to 90 mm, a reduction of 40.00%, and the peak horizontal stress decreases from 36.73 MPa to 31.20 MPa, a reduction of 15.06%. The support scheme effectively reduces the peak stress in the surrounding rock and minimizes deformation of the tunnel walls, verifying the reliability of the support scheme. The monitoring results from the test section indicate that scheme 3 provides good support performance. During the monitoring period, the cumulative subsidence of the roadway roof is 61 mm, the cumulative bottom bulge is 102 mm, and the cumulative lateral displacement of the roadway walls is 156 mm, effectively containing deformation and damage to the surrounding rock.

       

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