A stepped seawall with drainage is one of the coastal structures for reducing wave overtopping. The accurate prediction of wave overtopping is of importance in order to design the seawall economically. However, the previous design diagrams for the estimation of wave overtopping rate cannot be used for the complex shape of a seawall.
The main purpose of this paper is to investigate irregular wave overtopping process on a stepped seawall with drainage and verify the utility of a two-dimensional numerical wave flume “CADMAS-SURF” by implementing hydraulic experiments and numerical simulations. The comparison of the numerical and experimental results reveals that the CADMAS-SURF can appropriately reproduce wave overtopping phenomena under irregular wave actions.