WAVE OVERTOPPING WITH A CHANGING STEEP SANDY FORESHORE, CONVENTIONAL AND NUMERICAL ANALYSIS OF RESULTS

Abstract

Large scale tests were performed in the large scale facility GWK at Hannover, Germany, within the HYDRALAB+ project ICODEP: Impact of Changing fOreshore on flood DEfence Performance. The test set-up consisted of a relatively steep 1:15 sandy beach profile in front of a battered seawall with 10:1 slope (almost vertical). Two storms were generated, S1 and S2 with for each storm a specific combined surge and tide profile with varying wave conditions (sea states) depending on water level. These two types of storms have been modelled in varying order, giving three types of storm clusters (C1, C2, and C3). After each sea state the foreshore profile was measured and during each sea state wave conditions as well as wave overtopping have been measured. The changing foreshore showed a breaker bar formation as well as scour or accretion directly in front of the battered wall, depending on water level.