Edwin Rajeev

and 3 more

The Glass Window Bridge Located in Eleuthera, The Bahamas, is the only bridge connecting Eleuthera’s northern and southern mainland, facing the Atlantic Ocean to the east and the Great Bahama Bank to the west. This bridge is under constant threat from hurricanes and large swells in the Atlantic Ocean. The existing bridge has been subject to severe damage arising from wave impact forces since its construction. In addition, severe overtopping of the cliffs near the Glass Window Bridge causes damage to the roads and severe erosion, that over the years has created unique geologic features. As the global climate warms and sea level rises (SLR), coastal areas will be subject to more extreme flooding and intense hurricanes. Therefore, assessing the impact of potential SLR on the GW bridge and guiding bridge wave mitigation measures are of crucial need. A 3D Digital Terrain Model (DTM) of the bridge site and adjacent ocean bathymetry is constructed from satellite data. This study develops a multiphase computational fluid dynamics (CFD) model based on the DTM to study the impact of wave-breaking for three major historical storm events, and for three different estimates of SLR for the year 2100. Our results suggest that, due to SLR, the islands are subjected to increased overtopping, which occurs even during normal wave conditions. Notably, nonlinear increases in wave splash extent and wave-induced bridge loads are observed as SLR increases. Our results indicate that SLR additionally magnifies the erosional energy, accelerating further changes in the geological features of the island.