SUCTION BUCKET FOUNDATIONS FOR WIND ENERGY TURBINES: A NUMERICAL STUDY WITH FEM

Suction Bucket Jackets (SBJ) are found as a suitable alternative to driven piles for the support of jacket or tripod foundations for offshore wind energy converters. Offshore wind energy turbines are characterized by a small self weight and they can be subjected to different load combinations. The work presented here aims to show the numerical investigation on the behavior of suction bucket foundations under different kind of loads as well as load combinations. In order to do so, a suitable numerical model is much needed. The theoretical basis of the model lies on the Swansea formulation of Biots equations of dynamic poroelasticity combined with a constitutive model that reproduces key aspects of cyclic soil behavior in the frame of the theory of generalized plasticity. An adequate FE formulation, the representation of appropriate soil-structure interfaces and the computational efficiency are key aspects in order to successfully model such complex systems. The 3D numerical simulation allows a special insight into the fundamental behavior of the founding of Suction Bucket Jackets such as the evolution of the pore water pressure or the occurrence of the so called soil liquefaction.