Research on Collision Prevention of Inland River Bridges Considering Hydrodynamic Effects

Bridges spanning high-grade inland waterways generally feature large spans, large navigational vessel sizes, and high traffic density. As a result, these bridges face a particularly high risk of ship collision. However, previous bridge anti-collision designs often failed to comprehensively account for key factors, typically relying on simplified static calculations or neglecting environmental coupling effects, particularly the complex interactions among water flow, vessel motion, and structural response. This can lead to significant discrepancies between design assumptions and actual dynamic collision conditions.To more accurately assess the anti-collision performance requirements of newly built bridges and systematically optimize their design, this study uses a newly constructed large-span inland river bridge as the engineering background and develops a refined fluid-structure interaction numerical model that incorporates hydrodynamic effects to simulate realistic ship-water-bridge interactions. Specifically, HyperMesh was used for high-precision finite element meshing and preprocessing; LS-DYNA was employed to perform transient nonlinear simulations of ship collisions, capturing contact behavior, large deformations, and energy dissipation; and Midas Civil was applied to assist in analyzing and validating the global structural response of the bridge under impact loads. Key performance indicators were systematically quantified, including the time histories of ship impact forces, the resistance responses of critical bridge components, and the extent of structural damage to the vessel.The results show that hydrodynamic effects significantly influence ship-bridge collisions, with distinct mechanisms observed in ship-bridge and ship-anti-collision-bridge models. Therefore, hydrodynamic effects should be explicitly considered in bridge anti-collision research. Bridge anti-collision measures should focus on both enhancing the inherent impact resistance of the bridge structure and installing passive protective systems. The findings elucidate the mechanisms by which hydrodynamic effects act on vessels and protective facilities, demonstrating that proper consideration of hydrodynamics can significantly improve the design of anti-collision systems.