Longitudinal Seismic Response Analysis of Shield Tunnel Considering Different Curvatures

During the route selection process of river crossing shield tunnels, local bending often occurs due to avoiding unfavorable geological sections or terrain that meets the requirements for tunnel entry and extension at both ends, such as the Suzhou Haitai River Crossing Shield Tunnel. However, the influence of tunnel curvature on its dynamic response is rarely mentioned in existing research. In order to explore the changes in the internal force, tension, displacement, and other changes of the longitudinal direction pipe ring of shield tunnels with different curvatures under dynamic conditions, the longitudinal response displacement method is used. Based on the dynamic analysis method of long tunnel soil non-uniform excitation seismic response simulation, a multi particle beam spring model is established, Conduct longitudinal dynamic response analysis of shield tunnels with different curvature under multiple seismic input conditions. The calculation results indicate that the numerical model and calculation method can obtain a reasonable dynamic response of the tunnel structure; The dynamic response of shield tunnel increases with the increase of tunnel curvature; There are significant differences in the dynamic response of shield tunnels with different curvature when entering the soil boundary section. The research results can provide a more reliable and comprehensive calculation model and design basis for shield tunnel route selection and dynamic response analysis.