Modeling the Segmental Lining Behavior Using an Analytical Segmental Joint Model

To investigate the influence of joints on the segmental lining behavior for a shield tunnel, an analytical model incorporating the effect of the concrete and gaskets is proposed for the segmental joints. Based on the results of the analytical model, a beam-spring numerical model is established for the segmental lining, and parametric studies of the gasket and bolt are conducted to reveal the segmental lining behavior. The numerical results indicate that the joint has a slight influence on the axial force of the segmental lining but significantly affects the bending moment and deformation of the segmental lining. With increasing the gasket thickness or decreasing the gasket hardness, the maximum moment is decreased and the ellipticity is increased, which leads the bending capacity of the segmental lining to be decreased significantly. Therefore, the influence of gaskets should be an indispensable factor during the design of the segmental lining. However, with increasing the bolt pretightening force or the bolt cross-sectional area, the bending capacity of the segmental lining is improved only to a certain extent. Since the ellipticity of the segmental lining is slightly influenced by these bolt parameters, the improvement in the bending capacity can even be neglected.