Non-vertical spudcan impacts on a dense sandy seabed: improving design through centrifuge modelling

Abstract

Bottom-fixed wind turbines are often installed from a mobile jack-up vessel which is supported on spudcan foundations while on location. During emplacement, the spudcans may impact the seabed at an angle resulting in large stresses transmitted to the leg-hull connections. It is difficult to predict these stresses, particularly for dense sandy seabeds where uncertainty remains regarding shallow penetration resistances developed during high shear rates and reduced drainage. This paper considers the problem through centrifuge modelling with a dense sand sample. A model spudcan was attached to a ‘swinging’ loading arm to simulate dynamic, non-vertical impacts with realistic trajectories. Impact ..