Forces on a Vertical Wall due to Long Waves, Bores, and Dry-Bed Surges

Abstract

The forces and overturning moments on a vertical wall due to the reflection of solitary waves, undular bores, turbulent bores, and surges on a dry bed were determined experimentally. The incident wave celerity, wave profile, runup, force, overturning moment, and pressures were measured. The wave profiles and runup time histories were obtained with a laser-induced fluorescence system. The transition from undular to turbulent bores exhibits a large increase in the maximum measured wave slope, runup, force, and moment. For all cases, the maximum measured force and overturning moment were always less than that computed from the maximum measured runup using hydrostatic considerations. When properly normalized, the runup and force on a vertical wall due to the impingement of bores on a mildly sloping beach and a horizontal bed are shown to agree quite well. The results of this study may be used to estimate the forces on a vertical wall due to turbulent bores traveling on beaches with slopes no steeper than 1/50.