Analysis of bucket foundation installation in clay considering soil large deformation

Abstract

Bucket foundations are increasingly used to support offshore wind turbines. Its bearing performance has been extensively investigated, but its installation process has been addressed in a few investigations. This study investigates the penetration resistance during the installation of bucket foundations in clay through finite element models that consider large soil deformations. The proper finite element modeling scheme is assessed first, then a validated numerical model is employed to investigate the effects of length-diameter ratio and soil properties on the soil plug and penetration resistance. The results indicate that a minimum element dimension and penetration velocity should be set to 1/6th of skirt thickness and 0.3 m/s to ensure a good balance between computational accuracy and efficiency. An increase in the bucket length-to-diameter ratio increases the height of soil heave, while soil nonuniformity reduces it. In addition, the height of soil heave is slightly influenced by the friction coefficient and undrained shear strength of the soil. On the other hand, the penetration resistance is strongly affected by the soil undrained shear strength and bucket length-diameter ratio, but slightly affected by the friction coefficient.