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

TLDR

Bridge decks in Escambia Bay suffered damage during Hurricane Ivan’s storm surge, underscoring the need to understand wave forces at various deck elevations. The study aims to develop and validate a numerical wave‑load model and apply it to assess dynamic wave forces on the Escambia Bay bridge deck during Hurricane Ivan. A numerical wave‑load model employing incompressible RANS with k‑ε turbulence and a volume‑of‑fluid free‑surface formulation was used to simulate wave profiles, turbulent velocity fields, and dynamic uplift and horizontal forces on the full‑scale bridge deck. The model was validated against experimental uplift data, and simulations showed that during Hurricane Ivan the peak uplifting forces exceeded the bridge deck’s weight, directly damaging it, with results compared to empirical equations for hazard assessment.

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-ε 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.