This study systematically investigates the static and dynamic performance of the comprehensive structural system for the Huangmaohai extra-long-span three-tower cable-stayed bridge. A full-bridge finite element model was developed, incorporating elastic restraints at the central tower, viscous dampers at the side towers, and transverse seismic isolation bearings. Detailed structural parameters and loading conditions are provided. Subsequently, a systematic analysis was conducted on the structural stiffness, internal forces in the bearings, and stresses in the main girder and stay cables under static loads, thereby verifying the structural safety during both the completed bridge state and operational phase. Finally, through dynamic characteristic and seismic response analyses, the internal forces and displacement responses of the bridge towers in the baseline model and the comprehensive model under E1 and E2 seismic actions were compared. The results indicate that the proposed comprehensive structural system effectively controls main girder stresses, enhances structural stiffness, and significantly reduces seismic-induced internal forces. This research provides crucial technical bearing for the design and seismic optimization of similar extra-long-span cable-stayed bridges.
Shen et al. (Thu,) studied this question.