Short description
Dikes are central elements of technical flood protection and protect the riparians from flooding during flood situations. However, the last extreme floods on the Rhine, Elbe, Oder and their tributaries have shown that dikes as protective elements fail abruptly as soon as the dike crest is overtopped due to excessively high water levels. The water then flows over the landside dike flank and, despite low water depths, develops such high forces that erosion of the dike material occurs, leading to a reduction in dike thickness and weight. This is accompanied by the water-side hydrostatic pressure, which causes a rapid decrease in the stability of the shrinking dike body, which subsequently leads to the collapse of the dike.
Such a sudden failure of a flood protection measure is hardly predictable and thus leads to a high potential of damage and danger to the infrastructure behind the protection measure. Therefore, efforts are made to rehabilitate the dikes in such a way that an overflow can be withstood for at least a certain time, so that there is enough time for further protective measures (e.g. dike protection by means of sandbags).
The R&D project “Sicherer Deich” (safe dike) is testing the load-bearing capacity and stability of a dike planted with a special grass seed on behalf of the state of Hesse. For this purpose, the real-scale research dike of the TU Darmstadt is planted at the location of the dike master's office in Biebesheim and the seed growth is maintained over a period of three years under real conditions. Within the scope of different overflow tests, the throughflow and overflow behavior at different hydraulic load intensities is investigated by means of attached measurement technology. From the data and observations, statements on the stability and erosion stability of the special grass seed are derived and recommendations for its practical use are given.
The R&D project is being carried out in cooperation with Darmstadt University of Applied Sciences (The Chair of Hydraulic Engineering).
