An innovative scour protection for monopile structures was proposed by using geotextile sand containers in a research programme started recently. Large-scale model tests on the stability of such alternative scour protection are being performed in the Large Wave Channel (GWK) of the Coastal Research Centre (FZK). First results are reported from basic test series performed with single geotextile sand containers and container groups with different container weights, varied in sizes and percentages of filling. Further an empirical approach on the stability of sand containers is estimated as a first approximation from the results.
Creating renewable energy with wind turbines has increased rapidly in the previous years. This was mainly caused by environmental aspects with respect to carbon dioxide accumulation (greenhouse effect). But now also economical reasons become an important factor due to increasing prices and to shortage of fossil fuels as a consequence of increasing global energy consumption.
In some countries areas with effective wind conditions for wind turbines on land are restricted and increasingly occupied by wind turbines already. Thus, offshore areas become increasingly important for installing new wind parks. Otherwise technical and consequently economic boundary conditions for offshore wind parks are much more complex and difficult compared to the conditions of landside wind parks.
One of these complex and difficult offshore conditions relates to the foundation of the support structure, mostly designed as monopile structures. Such monopile support structures for offshore wind turbines in areas with movable sand beds may be affected by local scour processes due to wave and current action.
An innovative solution for monopile scour protection was proposed by using geotextile sand containers. Fig.1 shows a sketch of such a scour protection and the proposed model set-up for large-scale tests in the GWK.
