泥水盾构下穿已有隧道施工过程数值模拟研究

Numerical Simulation of the Construction Process of a Slurry Balance Shield Traversing Under an Existing Tunnel

针对2010年上海世博会重大配套工程——打浦路隧道复线工程,进行了数值模拟研究。根据工程实际,土体采用Drucker-Prager弹塑性本构关系,建立了沿弯曲路径下穿几何特性复杂的已有隧道的三维非线性数值模型,通过施加开挖面泥水压力模拟了泥水盾构施工过程,采用Newton-Raphson方法进行非线性求解。比较了轴线地表沉降数值模拟计算结果与工程实测数据,表明模拟模型可靠、可信;分析了泥水盾构施工对周围土体及已有隧道的影响,得到了已有隧道的位移和应力的变化规律,可为实际工程提供参考。

The Dapu Road double-track tunnel is an important auxiliary project of the Shanghai Expo 2010; a numerical simulation of this project using a 3D nonlinear finite element method is studied in this paper. The model of a slurry balance shield along a curved path traversing under an existing tunnel with complex geometric features was built and the construction process of a slurry shield was simulated by using Drucker-Prager elastoplastic constitutive and applying a slurry pressure. The model was solved by using the Newton-Raphson method and was proved to be reliable by comparing measured and calculated settlement. By analyzing the influences of the ground surface and existing tunnel, the displacement and stress of the existing tunnel were obtained.