Full scale impact tests of an overtopping bore on a vertical wall in the large wave flume (GWK) in Hannover

Abstract

To meet up with the requirements of the Flemish Government, the Belgian coastline needs a protection to a storm with a return period of 1000 years. At well-chosen locations, storm walls will be built, and for the structural design of these walls the impact loadings need to be known. Tests have been carried out at full scale in the Grosser Wellen Kanal, to determine the impact loads by overtopping bores. Wave overtopping over the crest of the dike occurs, and the overtopping bore progresses along the horizontal crest of the dike before impacting the storm wall. It is of major importance that such a wall can withstand the impacts. This paper describes the hydraulic process on the crest of the dike, expressed with parameters such as flow depth and flow velocity, and links them to the impact measured on the storm wall. Both pressures and forces are measured, and compared to each other.