Investigating the Characteristics of the Solitary Wave-Induced Forces on Coastal Twin Bridge Decks

Abstract

A computational fluid dynamics–based numerical parametric study for the characteristics of the solitary wave–induced forces on typical coastal twin bridge decks is conducted in this study. At first, the second-order solitary-wave model is developed followed by a verification process with the analytical one and a related experimental study. The laminar flow model and shear stress transport (SST) k-ω model are adopted and the comparisons of their results demonstrate that they can make close predictions for the bridge deck forces. Then, the general characteristics of the wave forces for a fixed deck gap and variable deck gaps with different still water levels (SWLs) and various submersion coefficients are observed. In addition, the characteristics of the wave forces on the landward bridge deck are presented by normalized factors based on the wave forces on the seaward deck. Finally, the hydrodynamic interference effects between the twin bridge decks are investigated and the effects of the deck vibration on the wave forces are demonstrated to represent more realistic scenarios in the field. This work provides engineers one possible criterion for judging or rating the magnitude of wave forces that will be exerted on the landward deck and the vulnerability of the twin bridge decks. This work also shed some lights on the revisions of the AASHTO code in 2008 regarding the wave forces on the twin bridge decks.