Wave Runup on and Wave Reflection from Coastal Structures

Wave runup and wave reflection are two of the most important, easily quantifiable variables that influence the design of coastal structures. Unfortunately there are very few comprehensive studies of these variables which give definitive and consistent guidance on prediction. This paper uses laboratory data from an extensive study of wave runup at the Coastal Engineering Research Center (CERC) to develop predictive equations for runup and reflection. The CERC study used irregular waves on plane, smooth, impermeable and non-overtopped slopes. These slopes ranged from 1 on 1 (vertical : horizontal) to 1 on 4. Predictive equations for wave runup and reflection were developed from the CERC data. The criteria used to develop the equations were that the equations fit the data well, be relatively simple, approach logical limiting values, and be consistent with the physics of the phenomenon as it is currently understood. Generally the criteria have been satisfied. In addition, the equations have been compared to the other data sets. Most comparisons showed that the prediction equations gave usefully accurate estimates of values and trends. However, the comparisons also suggest that one of the equations could be improved. The paper shows how this improvement was implemented.