The idea of the Wave Run-up Simulator is based on the experiences with the Wave Overtopping Simulator. It is possible to simulate wave tongues overtopping a dike crest in reality. It must also be possible to simulate waves in the run-up and run-down zone of the seaward slope. This is the zone after waves have broken and when they rush-up the slope. The present paper describes this new idea of the Wave Run-up Simulator, why it is useful to develop the machine, to perform research with it and to develop a prediction method for slope strength. In fact, a prediction method can already be developed from the Cumulative Overload Method, which was developed on the basis of results with the Wave Overtopping Simulator, see Van der Meer et al. (2010). It also means that tests on the seaward slope will be done for validation purposes only. The paper describes in detail what is known about the movement of waves in this run-up zone and what actually the Wave Run-up Simulator has to simulate. Not a lot of research has been performed to describe the wave run-up process in detail, physically nor statistically. Finally, the pilot test has been described including hydraulic measurements on the slope.

In March 2011 new wave overtopping tests have been performed in the Netherlands. In contrast to previous tests the grass cover of this dike was not maintained well, which had significant effect on erosion stability. Additionally, for the first time a pilot test has been made on wave run-up from an asphalt berm onto the grass covered upper slope of the dike. The tested dike sections had a sand core covered by a layer of clay and a grass cover. The objective was to test the erosion stability of seaward and landward slopes for wave overtopping as well as wave run-up. For the wave overtopping also the influence on erodibility of the grass cover caused by obstacles or other elements, which may be present at dikes (stairs, fences), was investigated.

Placed block revetments are constructed to withstand the wave forces on dikes, especially in regions where rip rap is not locally available, such as the Netherlands. The blocks are placed adjacent to each other on a filter layer to form a relatively closed and smooth surface, which is easy to walk on. Large-scale test in the Delta Flume of Deltares have been carried out to compare the stability of nine types of block revetments, presently on the market in the Netherlands (Klein Breteler, 2016). All tests have been performed with a comparable test setup and test program. The test program consisted of three series of tests. The first two series were short duration tests of 1000 waves with two different wave steepnesses, in which the wave height was increased step-by-step until damage occurred. The third test series was a long duration test lasting for 26 hours, or until damage occurred. The results of the tests have been used to quantify a correction factor in the calculation method. This correction factor, or stability factor, makes that the calculation method gives the same results as the Delta Flume tests, taking a safety margin into account. In this way the type-specific stability of each type of block revetment was better included in the calculation method.

No abstract

Placed block revetments are constructed to withstand the wave forces on dikes, especially in regions where rip rap is not locally available, such as the Netherlands. The blocks are placed adjacent to each other on a filter layer to form a relatively closed and smooth surface, which is easy to walk on. The present research is about the stability of block revetments under wave attack. It focusses on the stability in the run-up zone (above the stil water level, SWL) and compares this with the stability in the wave impact zone (below SWL). To obtain practical design formulae both small-scale and large-scale tests have been analysed, in combination with theoretical considerations based on the leakage length theory. Two types of hydraulic load are considered: a wave front that rushes up the slope (like a bore), and high velocity flow in the run-up and run-down. The later is especially an issue for revetments in which blocks are sticking out among adjacent blocks due to lack of maintenaince.