Abstract
To establish numerical analysis technology for quantifying the tenacity of coastal dikes, tsunami overflow over a coastal dike and local scouring at the toe of its landward slope are simulated and analyzed using a numerical model applicable to tsunami-scour interaction. Numerical results show that the approximation of the slope as a stepped profile causes the overestimation of water surface elevation and the underestimation of flow velocity over the landward slope, suggesting that it is essential to consistently model the smoothness of the slope for numerical analysis with rectangular numerical cells. Furthermore, it is found that the predictive capability of the model can be improved in terms of the final scour profile by taking into account the effect of infiltration/exfiltration in the sediment transport calculation, suggesting that the infiltration/exfiltration is of importance in analyzing local scouring due to tsunami overflow.
