Transverse seismic responses of a shield tunnel considering the influence of segment joints.

• Refined FE analyses were conducted to study the seismic responses of shield tunnels. • The peak value of the dynamic bending moment of each segment was consistent. • Seismic analysis of shield tunnel by the stiffness reduction method may result in errors. • Lining segment exhibits considerable rotation under earthquake loading. The segment joints of a shield tunnel are generally the weak components of the structure, and they can be considerably damaged under strong seismic loading, thus influencing the overall seismic behavior. In this study, Finite Element simulation analyses of centrifuge shaking table tests and a shield tunnel project are carried out to investigate the influences of the segment joints on the seismic responses and the associated mechanisms. First, the reliability of the numerical procedure is validated by using the centrifuge shaking table test results. The numerical procedure is then used, together with the refined simulation approach for segment joints, to carry out extensive numerical analyses of the seismic responses of a shield tunnel project under different horizontal earthquake loadings. The research results show that due to the influence of the segment joints, the peak value of the dynamic bending moment of each segment tends to be more uniform. When the stiffness reduction method is used to consider the influence of the segment joints, the peak values of the dynamic bending moments can be too large, while the peak values of the dynamic axial forces may be too small. In addition, the tunnel segment rotates during an earthquake, resulting in relatively large relative displacements of the segment joints. [ABSTRACT FROM AUTHOR]