Design of Offshore Wind Turbine Support Structures: Selected topics in the field of geotechnical engineering

Breaking the dependence on fossil fuels offers many opportunities for strengthened competitiveness, technological development and progress. Offshore wind power is a domestic, sustainable and largely untapped energy resource that provides an alternative to fossil fuels, reduces carbon emissions, and decreases the economic and supply risks associated with reliance on imported fuels. Today, the modern offshore wind turbine offers competitive production prices for renewable energy and is therefore a key technology in achieving the energy and climate goals of the future. The overall aim of this Ph.D. thesis was to enable low-cost and low-risk support structures to be designed in order to improve the economic feasibility of future offshore wind farms. The research work was divided in the following four selected research topics in the field of geotechnical engineering, relating to the monopile and the bucket foundation concepts:

1. Long-term response of monopiles
2. Modelling of advanced geotechnical problems
3. Interpretation of piezocones in silt
4. Buckling loads of bucket foundations

The outcomes of each of the four research topics contribute, either directly or indirectly, to enable low-cost and low-risk support structures to be put into use. Overall, these outcomes are an important contribution to increase the economic feasibility of future offshore wind farms.