INFLUENCE OF BRIDGE PIERS ON TSUNAMI FORCE ACTING ON BRIDGE UPPER STRUCTURES

Abstract

 Hydraulic model experiments and numerical analysis were carried out with the purpose of clarifying the influence of the existence of the piers on the tsunami force acting on the superstructures. In the hydraulic model experiment, the inundation depth and the impediment rate by bridge piers were varied as parameters, and the tsunami deformation around the pier and the tsunami force acting on the superstructure were measured. In the numerical analysis, we modeled the bridge piers as porous media and reproduced the tsunami deformation experiment by the VOF method. As a result, it became clear that as the impediment rate increases, the maximum flooding depth increases, and the vertical force acting on the superstructure also increases. In particular, when the inundation depth is large, it was found that the vertical force acting on the superstructure becomes larger than the buoyancy due to the reflected wave generated from the piers.