Study of Extreme Wave Forces on T-and Box-Types Girder

The extreme wave forces on costal bridges with T-type girder and box-type girder have great differences due to their special geometrical shapes. First, numerical models based on solitary wave theory and cnoidal wave theory were developed to simulate the tsunami waves and hurricane waves, in which the RANS (Reynolds-averaged Navier-Stokes) equations combined with the SST (shear stress transport) k-ω turbulence model were utilized to describe the mean flow motion, and the VOF (volume of fluid) method was used to trace the interface of air and water. Then, the effectiveness of the numerical models was verified. On this basis, the tsunami and hurricane induced wave forces on T-type girder and box-type girder were compared and discussed, considering different wave heights and submergence depths. The results show as follows: Tsunami wave induced horizontal peak forces on T-type girder are greater than those on box-type girder by over 32%; however, the box-type girder suffers greater vertical peak forces than the T-type girder and the maximum difference between them is near 31%. Hurricane induced horizontal peak forces on T-type girder are greater than those on box-type girder by over 31%; meanwhile, the vertical peak forces on T-type girder are also greater than those on box-type girder. Compared with hurricane waves, tsunami waves pose a greater threat to the safety of coastal bridges.