外滩通道平行开挖对既有大直径隧道的影响分析和设计方案优化

在软土地层中开挖基坑引起的基坑隆起,导致下方或侧方已有建构筑物的变形,从而对其使用功能和安全性产生影响甚至造成严重危害。外滩通道南段基坑设计共有两处邻接已建的延安路隧道:一是上跨已建延安东路隧道进行基坑开挖;二是延安路匝道处平行延安路隧道进行近距离开挖。该文对平行既有延安东路隧道开挖工程进行了研究,通过理论研究和工程比较制定了隧道的保护标准,比选了两种不同的设计方案并借助数值计算手段对既有隧道的变形进行了预测和验算。该文的一些结论和措施可以供今后类似工程参考。

Analysis on Influence of Parallel Excavation of the Bund Passage on the Existing large-diameter Tunnel and Optimization of Design Scheme

The pit upheaval caused by excavating the pit in the soft soil stratum will result in the deformation of the existing structures and buildings at the lower or the side places so as to influence its using function and security,indeed to cause the serious harm.There are two places to abut on the built Yan'an Road Tunnel in the design of the pit at the south section of the bund passage:the one is at the span crossing the built Yan'an East Road Tunnel for excavating the pit,and the other one is at Yan'an Road Ramp parallel to Yan'an Road Tunnel for the short-distance excavation.The article studies the excavation engineering parallel to the existing Yan'an East Road Tunnel.The article defines the protective standard of the tunnel by the theoretical study and the engineering comparison,compares and selects two different design schemes,and forecasts and check the deformation of the existing tunnel by dint of the numerical value calculation means.Some conclusions and measures in the article can be referred for the future similar projects.