Abstract
Some railway concrete bridges have been damaged and fallen by Tsunami. One of the reasons of the damage was lack of useful method for evaluating actions of the concrete bridges subjected to the water flow. Comprehending the influence of shape of cross-section of girders on water height, velocity, pressure, vortex generation, and energy loss is important to evaluating the action. In this study, influence of girders' cross-section shape on steady flow was discussed with hydraulics model tests of the past and numerical simulations.Vortex is generated under the overhanging girder and cause pressure increase in front of girders and pressure decrease behind girders. The power of horizontal fluid force suggested to depend on the length of overhanging girders.
