Shore and Bed Protection Structures

The interface of land and water has always played an important role in human activities; settlements are often located at coasts, river banks or deltas. When the interface consists of rock, erosion is usually negligible, but finer material can make protection necessary. In a natural situation, the interface moves freely with erosion and sedimentation. Nothing is actually wrong with erosion, unless certain interests are threatened. Then the erosion has to be “stopped”.

Dike revetment with concrete blocks 

Preferably the interface between land and water is maintained with “soft” engineering methods, like sand nourishment or vegetation. But in a number of cases this is not feasible for (socio-)economic reasons. In such situations heavier material is used that is resistant to erosion. Also the entrances to ports have to be protected against wave action and siltation. For that purpose also protective structures are needed.   

Often coastal structures built for other purposes (e.g. piers and quay walls) increase the wave and/or current load on the surrounding bed and shoreline, resulting in scour. Scour often leads to an unsafe situation for the original structure.

Examples of shore protections are riprap revetments, dike revetments with concrete blocks, breakwaters, groynes. Bed and scour protection structures usually consist of loose rock or fascine mattresses with geotextile. Materials that can be used are for example rock or loose concrete elements. But also vegetation can be used for this purpose.

This research group studies the interaction between water motion (by waves and currents) and the protective structures. The goal is to increase the understanding of the physical processes and to translate them to design requirements for the protection of shores, banks and the seabed. Also the interaction between currents/waves and vegetation is part of the research of this group. In case of scour it is important to determine the magnitude of scour and to develop protection methods against scour.

A breakwater under construction (by DMC)

Research focusses on improvement of these structures (make them more economic, more reliable and more environmentally friendly). Research goals are set in close cooperation with industry; the research is embedded for example in the Nevlock framework (NEderlands VLaams OnderzoeksCentrum Kustconstructies).

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