Shape optimization of gravity base support structures under consideration of wave and current loading

Gravity base foundations are particularly economical at sites consisting of a rocky substrate. Such conditions severely complicate pile driving and may cause a significant increase in the installation costs. When using gravity base foundations, a direct anchorage in the ground is avoided and the loads are solely transferred into the substrate through friction between the foundation and sea bed. Since these foundations are entirely exposed to the ocean environment, the shape of the foundation greatly contributes to the overall forces on the structure due to impacting waves and currents. The aim of this study is to
reduce the hydrodynamic forces on the foundations and to minimize the weight and size of the structures. Numerical investigations have shown that a shape optimization of gravity base foundations is particularly non-intuitive for combined wave-current scenarios and that further research is essential. In a first step, an experimental validation of the numerical methods will be conducted. Following, the numerical and experimental investigations can efficiently be used in conjunction to determine shape optimal designs. Medium-term the aim is to derive a catalogue of various foundation shapes that are specifically configured for possible environmental conditions encountered at offshore sites. The long-term goal is to develop a new generation of shape-optimized gravity base foundations, allowing for an efficient and economical realization of offshore
energy devices.