Rationalising offshore wind-turbine pile design and assurance in difficult ground

Nearly all offshore wind turbine foundations, whether monopile, tripod, jacket or floating wind turbines rely on strong piled foundations. However, difficult ground conditions are often encountered at North Sea and Baltic sites that make it hard to design foundations that are both effective and economic. Foundations can consume 25 to 30% of project costs and uncertainty over piled foundations can restrict or block the development of offshore renewable energy. A Consortium representing a major developer, Scottish Power Renewables, a leading University, Imperial College London, and a small firm of specialist geotechnical engineers (GCG, London) is working to drive costs down across the Industry, especially in Chalk-dominated, but otherwise promising, development areas. The key steps being taken are: (i) developing novel offshore test procedures that can be applied in all uncertain ground conditions, (ii) conducting a unique set of field tests in Chalk, drawing on recent advances made by the research and development team and (iii) synthesis with all available data to develop new more reliable design procedures. The work will cut the costs and risks faced by many major future projects.