Analysis of Failure Modes and Ultimate Bearing Capacity of a Special-Shaped Suspension Bridge Pylon

To investigate the working mechanism and failure modes of a special-shaped suspension bridge pylon under ultimate limit state conditions, a comprehensive analysis of the ultimate bearing capacity of a concrete self-anchored suspension bridge with a span of 130m+130m was conducted. A scaled model test of the bridge pylon was performed to verify the actual working performance and stress state of the star-diamond special-shaped pylon. Based on the material parameters and modeling methods from the scaled test, a 3D solid finite element model of the full-scale bridge pylon was established to simulate the most unfavorable loading conditions. This can provide a reference for the optimal design and subsequent construction control of the pylon. The results show that: the pylon reinforcement is reasonably configured and meets the requirements of the serviceability limit state; the pylon is mainly subjected to compressive stress, and flexural failure of normal sections and shear failure of inclined sections are not critical; under the ultimate bearing capacity state, the upper section of the pylon column preferentially undergoes axial compression failure, with the longitudinal reinforcement buckling outward and the stirrups being pushed open. The upper pylon column as a whole exhibits clear characteristics of flexural failure for a column structure. The stirrups and prestressing system should be configured reasonably.