Numerical study on the behaviors of coastal bridges with box girder under the action of extreme waves

Abstract

This study presents an in-depth investigation of the wave-girder interaction by considering the Fluid-Structure Interaction (FSI) effect. Firstly, a 2D FSI model is developed based on the overset mesh method. The model's validity is confirmed through comparisons with analytical wave surface and relevant experimental data. Subsequently, the model is employed to examine the girder behaviors under extreme wave action, including wave forces on the girder, dynamic response, and forces on bridge bearings. Moreover, parametric studies are carried out to assess how variations in girder dimensions affect the girder's behaviors. The numerical results indicate that the girder dynamic response effectively reduces the maximum wave forces on the girder, but simultaneously increases the horizontal bearing force. During the extreme wave action process, the seaward bearing experiences both tension and compression forces, whereas the landward bearing experiences only compression force. The deck thickness of the girder significantly influences its behaviors, necessitating an optimization design to minimize the failure risk of coastal bridges. This study provides valuable insights into the behaviors of coastal bridges under extreme wave conditions and offers references for designing and enhancing coastal bridges.