Prediction of Long-Term Deformations of Offshore Wind Power Plant Foundations Using Engineer-Oriented Models Based on HCA

The paper presents several engineer-oriented models based on the HCA model of Niemunis et al. (2005), dedicated to the prediction of long-term deformations of offshore wind power plant (OWPP) foundations caused by wind and wave action. A sub-layering model for shallow foundations under vertical cyclic loading and two different approaches (sub-layering model and stiffness degradation model) for monopile foundations subjected to a horizontal cyclic loading are presented. The results of these models are compared to the solution from complete 2D or 3D finite element simulations with the HCA model. Furthermore, the prediction is confronted with the prognosis of other engineer-oriented models proposed for OWPP foundations in the literature. Finally, a simplified procedure for the determination of the HCA material constants is briefly explained.