南京过江盾构隧道施工有限元仿真分析

Finite element simulation analysis of a river crossing shield tunnel construction in Nanjing

建立了南京过江盾构隧道三维模型,对施工掘进过程进行仿真分析。在盾首和盾尾采用生死单元的方法处理开挖面土体和衬砌单元刚度的变化。结果表明随着盾构机的掘进与盾尾管片拼装的持续进行,衬砌支护作用逐渐生效,变形趋于稳定,新的衬砌管片完成拼装后处于中部的管片应力峰值逐渐减小并最终稳定。

A three-dimensional model of a river crossing shield tunnel in Nanjing was established,and the construction and tunneling process was simulated and analyzed.The method of life and death unit is used in the shield head and tail to deal with the changes in the stiffness of the excavation surface soil and the lining unit.The results show that as the tunneling of the shield machine and the assembling of the shield tail tube segment continue,the lining supporting effect gradually takes effect and the deformation becomes stable.After the new lining segment is assembled,the peak stress of the middle segment gradually decreases and eventually stable.