复合内衬作用下C-T连接件纵缝接头抗剪力学性能的数值模拟研究

Numerical Study on the Shear Mechanical Behavior of Longitudinal Joints with C-T Connectors Considering the Effect of Composite Lining

摘要: 为研究复合内衬作用下C-T快速连接件纵缝接头的抗剪力学性能，建立了考虑复合内衬的纵缝接头三维有限元模型，分析了接头在剪切荷载及不同轴力作用下的受力特性、破坏形态与变形规律。结果表明，纵缝接头的受力过程可划分为摩擦、装配间隙弥合、连接件受力及混凝土破坏四个阶段，其极限抗剪承载力与轴力呈线性关系。T型连接件为主要受力构件，其腹板在剪切过程中同时承受剪力与拉力作用发生屈服，是接头中的薄弱部位。接头区域混凝土破坏以拉伸破坏为主，局部出现压缩破坏。数值结果显示，纵缝接头抗剪破坏时的错台量约为1.5 mm，轴力对错台量影响不显著；复合内衬具有良好的变形协调能力，其表面错台量较混凝土试块错台量平均降低约36%，能有效提高隧道内部光滑度与平整度。

Abstract: To investigate the shear performance of longitudinal joints with C-T rapid connectors considering the composite lining effect, a three-dimensional finite element model of the joint incorporating the composite lining was established. The mechanical response, failure modes, and deformation behavior of the joint under shear loading and varying axial forces were analyzed. The results indicate that the shear behavior of the longitudinal joint can be divided into four stages: friction, assembly gap closure, connector load-bearing, and concrete failure. The ultimate shear capacity of the joint exhibits an approximately linear relationship with the applied axial force. The T-shaped connector acts as the primary load-bearing component; its web yields under the combined action of shear and tensile stresses, constituting the critical weak region of the joint. Concrete damage in the joint area is dominated by tensile failure, accompanied by localized compressive failure. Numerical results show that the joint offset at shear failure is approximately 1.5 mm, which is only marginally affected by the axial force. Due to its favorable deformation compatibility, the composite lining reduces the surface offset at the joint by an average of approximately 36% compared with that between concrete segments, thereby effectively improving the smoothness and flatness of the tunnel’s inner surface.