Especially pressure surges caused by "plunging breakers" are critically important. There are some analytical models that describe loading due to plunging breakers on individual round poles. However, such approaches can only be applied to a limited extent to jacket structures as they are used in offshore wind energy plants. This is not surprising given the different levels of complexity in terms of hydraulic conditions.
To improve dimensioning methods for framework structures subject to pressure surge loading, physical modelling experiments were carried out using a large scale model at the FZK Large Wave Channel as part of the EU research program HYDRALAB IV. The experiments were commissioned by the Norwegian University for Science and Technology (NTNU) in Trondheim and Stavanger University (UiS).
Measuring 320 meters in length, 5 meters wide and 7 meters deep, the Large Wave Channel of the FZK is among the largest in the world. To make optimum use of the 800 kW output of the wave generator, the scaling of the model was defined as 1:8. The waves acting on the structure at this scaling were over two meters high. The rods in the framework consisted of steel pipes 14 cm in diameter. The dimensions of the overall structure were 2.4 x 2.4 x 4.9 m.