上跨高架市政隧道基坑中大桥桩基托换影响研究

Research on the Influence of Bridge Pile Foundation Underpinning in theFoundation Pit of Overpass Elevated Municipal Tunnel

文章针对南京长江大桥桥南延伸段桥改隧工程与地铁区间隧道下穿交叉工程施工过程,建立了对既有上跨高架桥影响的仿真受力模型,模拟了基坑开挖过程及桩基托换加固等重要施工工序,研究了市政隧道基坑周围环境的变化规律。大桥桩基托换及市政隧道基坑工程数值模拟的定性分析为施工方案提供了指导意见,施工引起的上跨大桥桩基变形影响控制在了合理的安全性要求范围内。

In view of the construction process of Nanjing Yangtze River Bridge south extension section reconstruction from bridge to tunnel engineering and the subway running tunnel underpass intersection engineering,this paper establishes a simulation force model for the influence on the existing overpass elevated bridge,simulates the important construction procedures such as foundation pit excavation process and pile foundation underpinning reinforcement,and studies the change law of the surrounding environment of the municipal tunnel foundation pit.The qualitative analysis of the pile foundation underpinning of the bridge and the numerical simulation of the foundation pit engineering of the municipal tunnel provides guidance for the construction scheme.The influence of the overpass bridge pile foundation deformation caused by construction is controlled within the reasonable safety requirements.