Overtopping Flow Parameters on the Inner Slope of Seadikes

Abstract

Wave overtopping was responsible for many dike failures in the past. It is not feasible to avoid wave overtopping completely in the future due to uncertainties in the prediction of the design water levels and the costs of uneconomical high dikes. Therefore, wave overtopping has to be taken into account for the design of seadikes. The overtopping flow velocities and related layer thicknesses are required which are responsible for infiltration and erosion of the dike crest and the landward side of a dike. The objective of this paper is to study the flow velocities and related layer thicknesses associated with wave run-up and wave overtopping based on theoretical and experimental investigations.

Improvements in Describing Wave Overtopping Processes

“…Earlier experiments (Schüttrumpf, et al, 2002;Schüttrumpf and Oumeraci, 2005;and Van Gent, 2002) yielded empirical expressions for the maximum individual wave flow thickness (h 2% ) and maximum velocity (U 2% ) exceeded by only 2% of the overtopping wave maximum values. These 2%-exceedance parameters were related to incident wave conditions and dike freeboard.…”

Influence of Mild Bottom Slopes on the Overtopping Flow over Mound Breakwaters under Depth-Limited Breaking Wave Conditions

“…Schüttrumpf and Van Gent [8] integrated the results of Van Gent [11] (m = 1% and 0.2 ≤ Hs/hs ≤ 1.4, Hs being the significant wave height at the toe of the structure and hs the water depth at the toe) and Schüttrumpf et al [12] (horizontal bottom and 0.1 ≤ Hs/hs ≤ 0.3) and described the overtopping flow on dike crests using two variables: (1) the OLT on the dike crest exceeded by 2% of the incoming waves, hc,2%, and (2) the OFV on the dike crest exceeded by 2% of the incoming waves, uc,2%. These authors also proposed a method to estimate hc,2% and uc,2% based on the wave run-up height exceeded by 2% of the incoming waves, Ru2%, obtained with the formulas proposed by Van Gent [13].…”

“…(z A = R c ) and u A,2% (z A = R c ), OLT and OFV on the crest of the dike, h c,2% and u c,2% , are estimated using the distance from the intersection between the seaward slope and the crest, x c , the crest width, B, and a friction coefficient, µ (see [12] for further guidance on this coefficient).…”

Overtopping Flow Properties Characterization in Laboratory and Prototype Through the Combination of Non Intrusive Instrumental Techniques

“…With the aim acquiring deeper knowledge of overtopping events, several instrumental techniques have been developed and applied in the last decade to overtopping analysis, both in lab and prototype tests (Schüttrumpf H. et al 2002;Pullen T. et al 2003;Troch P. et al 2004;De Rouck J. et al 2004;Briganti R. et al 2005;Pullen T. et al 2009). The use of these techniques has allowed both obtaining additional overtopping key responses, and modifying previous existing ones in order to obtain a better characterization of overtopping events (see "modified mean overtopping discharge (q new )" Campos, A et al 2012).…”