Abstract

Offshore wind is expected to play a major role in the future of renewable energy. To meet its target that 15% energy be produced from renewables, the UK government aims to construct 7,000 turbines that will generate 33GW of energy. Offshore wind turbines often use large diameter monopiles as foundations. These monopiles must be designed both to support the vertical and lateral loads of the turbine and to provide sufficient stiffness to prevent system resonance. When these foundations are installed into clay, there is a significant potential for the performance of these piles to change over time due to the cyclic loading applied by the turbine. Centrifuge testing of scale model monopiles in overconsolidated speswhite kaolin was carried out to investigate the monopile’s lateral behaviour and asses the change of stiffness under cyclic loading. Based on the results, recommendations were developed to optimise and improve foundation design for long-term performance.