Characteristics of flow in run-up of periodic waves

The run-up of waves is an important factor in the design of shore structures. It has been investigated in many studies, both theoretical and experimental. The experimental studies have mostly been confined to the maximum run-up (the greatest height above still water level, reached by the periodic waves on the slope). A simple and reliable formula for the maximum run-up is given by Hunt (I), based on measurements with periodic waves breaking on smooth plane slopes. However, virtually no data are available regarding the characteristics of the flow in the up-rush and the down-rush on a smooth slope, such as layer thickness, particle velocity, wave front velocity, and so on. Such information can be of use in developing or adjusting schemes for numerical calculation of run-up and overtopping, as well as in problems of stability of cover layer material or of seepage of water into the core material of a dike. The purpose of this report is to present empirical results concerning the above-mentioned flow parameters, obtained from experiments with periodic waves breaking on smooth plane slopes. In the analysis of the data considerable attention is given to similarities in the run-up process; the existence of such similarities had previously been inferred from Hunt's formula for the maximum run-up height.