Abstract:

Considering the safety, cost and operation of a working shaft of Weisanlu Rivercrossing project in Nanjing, the author analyses the characteristics of the project and decides to take the composite wall as the support of the working shaft. The author mainly analyses the working behaviour of the diaphragm wall in the construction stage, and obtains the relationship between the ground settlement and the support rigidity, then concludes that the diaphragm wall is better than the retaining piles in terms of ground settlement control. Then, the author establishes 3D finite element models, simulates the construction and operation of the working shaft by SAP2000, and studies the characteristics of the deformation and internal forces of the support. By comparing 2D numerical simulation with 3D numerical simulation, the author gets the result that the spatial characteristics of the retaining structure of the working shaft cannot be ignored in the structure design. The author concludes that the application of composite wall in the working shaft is rational. The study can provide reference for similar projects in the future.

Key words: Weisanlu Rivercrossing project in Nanjing, shieldbored tunnel, superdeep and superlarge working shaft, composite wall, numerical simulation