Experimental and computational analysis of hybrid suction caisson foundation for next-generation offshore wind turbines

A suction caisson is a successful foundation for an offshore wind turbine (OWT). High-capacity next-generation wind turbines become essential due to the rising demand for renewable energy. To support such turbines, a new foundation is required that can sustain the greater environmental loads. To satisfy the requirements of high-capacity OWTs, a hybrid suction caisson (HSC) foundation is developed in the study. The performance of the HSC is examined by conducting a number of physical model tests. Experimental results show that horizontal bearing capacity improved by 69.99% compared with a conventional suction caisson foundation. The increase in external skirt depth of HSC from 0.25L to 0.5L (L = 100 mm; inner skirt depth) and the increase in lid diameter from 250 to 300 mm show the 20.05% and 21.82% improvement in horizontal bearing capacity, respectively. Test results of the study reveal a significant improvement in its performance compared to a conventional caisson. Numerical simulations are also carried out to elucidate the mechanism.