邻近既有地铁综合管廊“先隧后井”施工可行性研究

Feasibility Study on the Construction Scheme of"Tunnel before Well"Adjacent to the Existing Subway Integrated Pipe Corridor

为探究邻近既有地铁综合管廊采用“先隧后井”施工方案的可行性,依托深圳地铁14号线共建管廊简易1号综合井项目,通过数值模拟、现场监测,分析了施工过程中综合井围护结构以及既有地铁的变形响应特征。结果表明:(1)管廊施工对围护结构稳定性影响较小,综合井的开挖卸荷才是导致围护结构变形的主要因素;(2)既有地铁变形呈现出以综合井中心线为对称轴、中间大端头小的对称分布特征,施工过程中应适当增加强影响区的监测点位布置;(3)通过严格控制盾构掘进参数,采取针对性的洞门防水措施,加强监控量测及信息反馈,能有效保障邻近既有地铁综合管廊“先隧后井”施工安全,可为类似工程优化和安全施工提供参考。

In order to explore the feasibility of adopting the"tunnel first and well later"construction scheme for the adjacent existing subway integrated pipe corridor,the deformation response characteristics of the integrated well envelope and the existing subway during construction were analyzed through numerical simulation and on-site monitoring,relying on the Shenzhen Metro Line 14 integrated pipe Corridor Simple No.1 integrated well project.The results show that:①the pipeline corridor construction has little effect on the stability of the envelope structure,and the excavation and unloading of the integrated well is the main factor leading to the deformation of the envelope structure;②The deformation of the existing subway shows a symmetrical distribution with the center line of the integrated well as the symmetry axis and the middle end as the small,so the monitoring point layout of the strong impact area should be appropriately increased during the construction process;③By strictly controlling shield tunneling parameters,adopting targeted tunnel door waterproof measures,and strengthening monitoring and measurement and information feedback,the construction safety of"tunnel before well"in adjacent integrated tube corridors can be effectively guaranteed,and can provide reference for optimization and safe construction of similar projects.