Constitutive modelling of cyclic sand behaviour for offshore foundations

The wind energy industry has gained a key role in the global fight against greenhouse gas emissions. Although fossil fuels have still the largest share in the global energy mix, the production of wind energy, especially offshore, has rapidly grown since the 1990s. According to the International Energy Association, Europe targets offshore wind to become the main electricity source by 2040. To meet such a goal, significant developments in research and technology are ongoing to reduce/optimise the high costs for materials, manufacturing, transportation, and installation of offshore wind farms. A significant cost item for offshore wind turbines (OWTs) is represented by their supporting structures and foundations, especially as the rush towards bigger OWTs and larger water depths poses a serious threat to cost reduction targets. To make offshore wind competitive in the energy market, reducing investment costs is mandatory. Since OWT foundations mobilise up to around 18% of the total investment in typical offshore wind projects, the importance of reconsidering/improving geotechnical design approaches for offshore foundations is selfapparent.