Abstract:

The shieldbored tunnel from North Tibet Road Station to Zhongxing Road Station on No. 8 Line of Shanghai Metro has straight segments joints. In the paper, the deformation of the lining structure of the shieldbored tunnel is monitored, the equivalent continuous model is modified, the influence of the tunnel convergence deformation on the longitudinal deformation of the lining structure is considered, and comparison and contrast is made between the calculation method with consideration of the convergence deformation and the existing calculation methods, so as to study the influence of the transverse deformation of the lining structure on the longitudinal deformation and stress of the lining structure during the operation of the Metro system. The results show that: 1) Under bending conditions, the maximum opening of the ring joints at the invert, the tensile stress and compression stress of the segments and the tensile stress of the bolts decrease as the tunnel convergence deformation increases, without considering the shear at the ring joints. 2) The influence of the tunnel convergence deformation on the lining structure increases as the curve radius decreases. 3) Under the condition of the longitudinal deformation of the tunnel structure with large curvature radius, the influence of the tunnel convergence deformation on the longitudinal deformation of the lining structure can be ignored; Without considering the longitudinal deformation of the lining structure induced by axial tensioning, the opening of the ring joints at the invert caused by the structure curvature is small .

Key words: shieldbored tunnel, convergence deformation, longitudinal deformation, equivalent bending stiffness, elliptic equation