Insights into Suction Caisson Installation Utilising the Material Point Method

There is an increasing interest to utilise suction caissons as foundations for offshore wind turbines. Significant research has been devoted to developing penetration prediction methods and to understand the in-service response under cyclic loading. However, the effect of the installation process on the state of the surrounding soil is less well understood, although it may affect the in-service performance, in particular under relatively low magnitude cyclic loading, which represents the majority of loading conditions experienced by an offshore wind turbine in the field. This is due to the complexity in modelling the problem, which includes very large deformations, seepage flow and soil-structure interaction. Novel approaches featuring the material point method and centrifuge test results evaluated with the particle image velocimetry post analysis are capable of visualising the mechanisms underlying suction caisson installation. The results aim to reduce existing uncertainties and provide confidence in suction caissons as a reliable foundation system for offshore wind applications.