Drained Capacity of a Suction Caisson in Sand under Inclined Loading

Abstract

Suction caissons have recently been considered as potential anchoring solutions for floating renewable devices (wind turbines and wave energy converters) in shallow waters, where—unlike for floating oil and gas applications in deep water—sandy seabeds are to be expected. This paper presents a simple framework to calculate the maximum drained capacity of a caisson under inclined loading in sand and the associated position of the padeye, as a function of the load inclination. The framework assumes critical-state conditions and is based on the establishment of yield envelopes in the horizontal and vertical loading space at the location of the padeye. The yield envelopes were established through numerical modeling and validated by centrifuge tests; they are described by a closed-form solution that enables the prediction of caisson capacity.