四方金矿王家院尾矿库排洪隧洞掘进支护安全施工与实践

Drainage Tunnel Excavation Supporting Safe Construction and Practice of Wangjiayuan Tailings in Sifang Goldmine

四方金矿新建尾矿库排洪隧洞设计断面为4m×4.2m,掘进断面虽不大,但由于施工工期紧,贯穿整个隧洞的岩性变化大,尤其是隧洞出口部位由薄层千枚岩组成,虽未发现明显变形破坏迹象,但由于节理切割及卸荷裂隙影响,表面拉裂松动现象发育,洞脸边坡开挖时产生滑塌,严重影响施工安全和进度。经过施工技术方案分析比较,采取超前锚杆和挂网喷浆、钢支架等临时支护措施后,为确保安全施工和提前完成施工计划赢得了时间。

The drainage tunnel design section of new tailings in Sifang Goldmine is is 4m×4.2m, which is not too large. However, due to the tight construction schedule and the big lithology variation throughout the entire tunnel, especially the tunnel exit site is consists of the thin phyllite, although there are not obvious signs of deformation damage, affected by the joints cutting and unloading fissure, surface crack loosening is growing, and slump produced in the slope excavation of hole face, which seriously affects the safety and progress of construc- tion. After the construction technology program analysis and comparison, they take temporary support measures of advanced anchor, hanging net guniting and steel bracket to ensure the safe construction and gain time for completed ahead of construction plan.