Analysis of fluid-structure interaction on a bridge wash out phenomenon with the particle finite element method

In 2011, a huge tsunami stroke the north-eastern Japanese coast and caused numerous devastations, especially on public infrastructures such as highways, railways, bridges, etc. As bridges are essential for the recovery and prevention of a tsunami strike in terms of transporting goods and people, the prevention of the wash out phenomenon of the upper structure of the bridge is very important. With this motivation, a study of the wash out behaviour has been carried out using the Particle Finite Element Method (PFEM) for solving fluid-structure interaction problems. To validate the simulations carried out, a comparison between the simulations and some real-life experiments has been made. In the experiments, the motion of the girder (upper part of the bridge) has been tracked during the hit of the wave. Plus, a comparison between the simulations of the same problem with different mesh sizes has been done in order to compare and judge which mesh size best fits this specific problem. It is found that the rigid body motion of the girder of the bridge shows good agreement with the experimental results, and the optimal mesh size for this problem regarding the accuracy of results and computational time is the 10-mm mesh size