Abstract:

A case study is conducted on the Shasan station of the Shenzhen metro line 12 to realize the construction of a largecrosssection prefabricated metro station using a smallcrosssection pipejacking machine. In addition, the construction scheme and mechanical properties of the station constructed by the twintube closely spaced pipejacking method are investigated. First, the structural design concept of this novel method is presented, including the crosssection division and structural transformation of the station along with construction procedures. Furthermore, the transformation method for the vertical and transverse force system and the construction processes for transforming the twintube substructure into the integral station structure are proposed based on the characteristics of the proposed construction method and the station structure. Second, the segmentation of the ring substructure, structural joint design, and waterproof system design are introduced. Finally, the variation law of the bending moment of the station structure during the construction process is analyzed by a threedimensional finite element model established using the finite element software ABAQUS and based on the loadstructure method. The study shows that the peak values of the bending moments of the left and rightline substructures of the station slightly change during the construction process, demonstrating the rationality of the construction procedure. Meanwhile, the bending moments of the left and rightline substructures vary due to the asymmetric design of the joint position and different boundary conditions during construction. Therefore, the bending momentcontrolling section should be carefully considered in the design of the station structure.

Key words:

 , twintube closely spaced rectangular jacking pipes, prefabricated metro station, joint, structural design, structural transformation, waterproof design, force analysis