Abstract
In this study, the applicability of a numerical model for the predicting of local scour at the
downstream of a weir, which has been developed by the authors in the river field, to the local
scour at the toe of a coastal dike induced by tsunami overflow was investigated. Furthermore,
the influence of the difference between equilibrium and non-equilibrium bed load transport
models on the reproducibility of the phenomenon was also examined. The results showed that
the model was able to reproduce well both the tsunami overflow situation and the local scour
progression with repeated flow regime transitions. Moreover, the non-equilibrium model
reproduced a smooth scour shape extending from the top of the foundation as in the experiment,
while the equilibrium model produced deep scour just below at the toe of the dike. In addition,
it was also clarified that the coefficient of the suspended load formula had a significant effect on
the reproduction of the phenomenon.
