Numerical Study of the Effect of Tsunami Waves on Offshore Box Beam Bridges

Coastal bridges are threatened by extreme loads such as typhoons, storm surges, and tsunamis due to their unique location. Ensuring the safety of coastal bridges during extreme weather events is crucial for minimizing loss of life, economic impacts, and expediting post-disaster recovery and reconstruction. A two-dimensional numerical water tank is established in OpenFOAM to simulate tsunami waves using the dam-break wave model. The Reynolds-averaged Navier-Stokes (RANS) equations and k-ε turbulence model are employed. The Volume of Fluid (VOF) method is utilized to capture the water surface. A downsized model at a scale of 1:20 was used to analyze the wave forces acting on the structure in terms of various tsunami like wave and bridge clearance scenarios. The results indicate that the effect of the tsunami like wave on the model can be broken down into three phases: initial impingement, decay and stabilization. The peak force acting on the model varies directly with wave height and inversely with bridge clearance.