Evolutionary patterns of vertical wave-impact forces on the superstructure of box girders: An experimental study

Box girders are a standard configuration in superstructures of coastal bridges, and wave impacts compromise their safety. In this study, a hydrodynamic experiment was conducted on a single-cell box girder at a scale of 1:25 to investigate the characteristics and mechanisms of wave forces acting on the superstructure. The vertical wave force evolution patterns were classified into five distinct categories. The mechanisms underlying these patterns were further examined using particle image velocimetry (PIV) and bubble image velocimetry (BIV) results. Two non-dimensional parameters were proposed to identify wave impact patterns on the box girder, providing insights into the causes and potential failure modes of bridge superstructures. Meanwhile, the influence of the wave height and period on the vertical wave force was also investigated. This study offers valuable insights into the understanding and mitigation of wave-induced impacts on box girder bridges under various wave scenarios and supports the design of resilient nearshore bridge structures.