长沙地铁越江隧道穿越岩溶地层关键技术研究

Research on the Key Technology of Changsha Metro Cross-river Tunnel through Karst Stratum

研究目的:长沙地铁3号线阜埠河站-灵官渡站区间是穿越湘江及江中橘子洲的越江隧道区间,江底存在不同程度的岩溶发育区,工程及水文地质条件复杂,实施难度大。长沙地区尚无越江隧道长距离下穿江底岩溶强发育区先例,为解决复杂岩溶水底隧道穿越技术,降低施工风险,实现隧道穿越水下岩溶地层,本文对复杂岩溶水底隧道关键技术体系进行研究,以期为类似工程建设提供借鉴。研究结论:(1)对于越江隧道,通过确定合理过江线位方案,绕避岩溶区,能有效地减小岩溶穿越区距离,降低工程风险;(2)岩溶区越江隧道采用泥水盾构掘进工法,工程风险更为可控;(3)对于岩溶处理平台采用水上钢平台,能有效地减小岩溶处理产生的环境影响;(4)岩溶注浆处理通过制定合理注浆方案、注浆参数,保证溶洞处理效果并控制投资;(5)盾构掘进过程需合理控制,工筹安排应结合试验段开展,精细化控制盾构掘进过程;(6)本文关键技术体系对其他同类地层隧道施工具有一定借鉴作用。

Research purposes: The section of Changsha Metro Line 3 between Fubuhe station and Lingguandu station is a tunnel across Xiangjiang River and Juzizhou Island. Karst caves exist at the bottom of the river to some degree and the hydrogeological conditions of the project are complex,which bring significant risk to the construction. There is no precedent for long-distance tunnel crossing the river bottom karst strong development area in Changsha area. In order to solve the problem of complex karst underwater tunnel crossing technology,reduce the construction risk and realize the tunnel crossing the underwater karst stratum,this paper studies the key technology system of complex karst underwater tunnel,to provide reference for similar engineering construction.Research conclusions:( 1) For the tunnel crossing the river,it can effectively reduce the distance of the karst crossing area and reduce the project risk by determining the reasonable crossing line plan and avoiding the karst area;( 2) The tunnel crossing the river in the karst area adopts the slurry shield tunneling method,so the project risk is more controllable;( 3) The steel platform on water is used for the karst treatment platform,which can effectively reduce the environmental impact of the karst treatment;( 4) Karst grouting treatment can ensure the treatment effect of karst cave and control the investment by making reasonable grouting scheme and grouting parameters;( 5) The shield tunneling process needs to be controlled reasonably,and the work preparation and arrangement are carried out in combination with the test section to control the shield tunneling process finely;( 6) The key technical system in this paper has reference and guidance significance for the tunnel construction in other similar strata.