Numerical Modeling of Dynamic Wave Force Acting on Escambia Bay Bridge Deck during Hurricane Ivan

Abstract

Bridge decks in Escambia Bay were damaged during the storm surge of Hurricane Ivan in 2004. In this study, a numerical wave-load model based on the incompressible Reynolds averaged Navier–Stokes equations and $k\text{-}\epsilon$ equations has been used to investigate dynamic wave forces exerted on the bridge deck. The volume of fluid method is adopted in the model to describe dynamic free surface, which is capable of simulating complex discontinuous free surface during wave breaking and wave-deck interactions. The model was satisfactorily tested against experimental data of uplift wave forces on horizontal plates. The validated model was applied to investigate wave forces acting on the bridge deck in Escambia Bay in the case of Hurricane Ivan. The time history of wave profiles, turbulent velocity fields, and dynamic uplift and horizontal forces acting on the full-scale bridge deck were simulated and analyzed. Results indicate that, during the storm surge event of Hurricane Ivan, the maximum uplifting wave forces were larger than the weight of the simply supported bridge deck, causing direct damage to the deck. Wave forces on three different deck elevations are discussed. Comparisons of numerical modeling results to maximum wave forces obtained from empirical equations are provided as references for coastal hazard assessment and bridge design.