高速铁路隧道下穿尾矿库开挖安全稳定研究

Research on Safety and Stability of the Tailings Reservoir During Excavation of Underpass High-Speed Railway Tunnel

尾矿库是防止环境污染的重要环保设施,一旦发生渗滤液渗漏、溃坝等,后果极为严重。当隧道从下方穿越尾矿库时,对尾矿库安全稳定存在一定影响。依托粗铅、电锌及渣综合利用工程的配套尾矿库旁大羊山隧道穿越项目,开展隧道开挖方式及尾矿库堆载对于尾矿库安全稳定的研究。经地质预报和监控量测分析,在离尾矿库较远处隧道采用控制爆破开挖,近接范围内采用机械开挖。利用数值模拟软件FLAC 3D,分别建立隧道机械开挖数值模型与尾矿库三维数值模型以分析隧道机械开挖及尾矿库堆渣对地表沉降影响。结果表明,隧道开挖造成的地表沉降对尾矿库最大影响约2.08 mm,尾矿库堆渣本身造成的地表沉降约10 mm,隧道开挖造成的地表沉降值小于尾矿库堆渣造成的地表沉降值。因此,隧道开挖不会对尾矿库安全造成影响。

Tailings reservoir is an important environmental protection facility to prevent environmental pollution.It would have terrible consequences once the disasters happen,such as leachate leakage or dam failure,and so on.When the tunnel passes underneath the tailings reservoir,there are certain impacts on the safety and stability of the tailings reservoir.Relying on the Dayangshan Tunnel crossing project next to the supporting tailings reservoir of crude lead,electric zinc and slag comprehensive utilization engineering,the research on the impact of tunnel excavation methods and tailings pond loading on the safety and stability of the tailings reservoir is carried out.After the geological forecast and monitoring measurement analysis,the tunnel is excavated by controlled blasting at a distance from the tailings reservoir,and mechanical excavation is used within the adjacent area.The numerical simulation software FLAC 3D is used to establish numerical models of tunnel mechanical excavation and three-dimensional numerical models of tailings reservoir to analyze the impact of tunnel mechanical excavation and slag heap on surface settlement.The numerical calculations show that the maximum impact of surface settlement caused by tunnel excavation on the tailings reservoir is about 2.08 mm,the surface settlement caused by the tailings reservoir slag heap itself is about 10 mm,and the value of surface settlement caused by tunnel excavation is smaller than the value of surface settlement caused by the slag heap in the slag bank.Therefore,tunnel excavation will not affect the safety of the slag depot.