Performance evaluation of anti-overturning reinforcement for spatial curved girder bridges with single-column piers via vehicle-bridge coupling simulation

Frequent overturning accidents of curved girder bridges supported by single-column piers under regular heavy trucks and super-heavy special-transport vehicles have exposed insufficient anti-overturning capacity. In engineering practice, a variety of reinforcement measures are adopted, such as converting a single-bearing into multi-bearing, adding bearings, and installing uplift-resisting devices. How to evaluate the effectiveness of different reinforcement schemes remains challenging: existing studies largely rely on energy methods or refined solid finite element models (FEM), which suffer from complex derivations, cumbersome modeling, and low computational efficiency. This study first establishes a complete analysis framework for coupled vibration of spatial curved bridges and heavy vehicles by comprehensively considering: the non-coincident dynamic trajectories of individual wheels on curved alignments, finite element simulation of radial and tangential bearings, and wheel-by-wheel loading patterns on curved girders. A transverse overturning instability criterion for box-girder bridges with single-column piers is embedded to develop an integrated simulation and assessment module for heavy vehicles traversing curved bridges. Finally, taking a real reinforcement project of curved girder bridge with a single-column pier as an example, the reliability of the system was verified. On this basis, the dynamic responses and anti-overturning performance after converting a single-bearing to multi-bearing is analyzed, and the influence of truck mass, lateral loading position, reinforcement pier location, and number of reinforced piers are systematically investigated. The results provide a theoretical basis and technical support for reinforcement design and safety assessment of similar bridges.