大直径盾构隧道下穿既有车站诱发车站结构变形分析

采用三维有限差分程序模拟城市大直径盾构隧道施工,基于此分析了上部地铁车站的结构变形并考虑了车站变形缝的影响.计算选用了地层-结构模型,土体则采用弹塑性模型模拟,应用link单元模拟变形缝,并对link单元的本构关系及参数进行了详细的定义.重点进行了结构间相互作用分析及变形缝的模拟.结果表明:考虑变形缝,结构变形更加灵活,充分;差异变形发生在地层刚度变化大的部位;变形结果为结构安全评估提供了可靠的依据.

Deformation Analysis of an Existing Subway Station Structure Traversed Down by a Large Shield Tunnel

This paper discusses focused on the structure deformation caused by a large cross shield tunnel traversing down a subway station.The diameter of the shield tunnel is 11m.Three-dimensional finitedilierence program is used for simulation of large diameter shield tunnel.The numerical simulation scheme is based on a soil-structure model,in which the plastic model is used in calculation to describe the soil behavior and the link element is used to simulate the deformation joint of the station structure.The constitutive relationship and the parameters of the link element is defined in a specific way.It is found that the structure becomes flexible with deformation joint considered in model,and the prediction of deformation is more reasonable to conduct risk evaluation of station structure.