DAMAGE PREDICTION OF A DIKE AND A SEAWALL BY BIG WAVES

Abstract

 In the case of a coastal dike and a seawall in a beach or a shallow area, there are a few of field cases that those are destroyed directly by strong wave force and a lot of field cases that scour in front of them and suction from their bodies caused by the continuing action of waves bring their destruction gradually. Therefore, it is important for us to establish the prediction methods of the scouring rate in front of them and the suction rate from their bodies. In this research, first, the accuracy of the 2-D numerical model of Ca et al. is comfirmed by using field data on the scour. Then, the diagrams to estimate the maximum scour depth are proposed. Next, the experiments of the suction from their bodies in which the grain diameters of back filler are changed are conducted. Then, the formula of effective shear resistance force in which the influence of the grain diameter can be considered is proposed also.