Research on the effects of curvature and shear keys on torsional stiffness and interfacial stress of segmented U-shaped curved bridge.

This paper investigates the segmental U-shaped curved bridge of Bogotá Metro Line 1 project in Colombia. The effects of curvature radius (R) of the bridge and shear keys (number, arrangement, and size) at inter-segment bonding joints on the bridge's torsional stiffness and interfacial stress are analyzed. The results demonstrate a nonlinear relationship between bridge curvature and torsional stiffness. As the curvature radius increases, torsional stiffness enhances while the growth rate declines gradually. Increasing the number of shear keys in the web and floor regions of U-shaped bridge segments, along with extending their width, effectively enhances the bridge's torsional stiffness and global deformation resistance while ameliorating the interfacial stress state between segments. These findings offer both theoretical and practical guidance for the design of segmental U-shaped curved bridges and shear key systems.