Centrifuge modelling of two-way axial cyclic response of screw piles for offshore wind

Screw piles have been proposed as an innovative silent foundations/anchor solution for offshore renewable energy applications such as fixed or floating wind. Such application requires a deeper understanding of the influence of increases pile size and offshore loading conditions on performance of screw piles. To date two-way axial cyclic response of screw piles has not received sufficient attention, which may be encountered in offshore jacket structures. This investigation conducted both one-way tensile and two-way cyclic loading tests on a screw pile designed for offshore wind turbines using a geotechnical centrifuge. The results suggest that, when the cyclic amplitude is the same, the two-way loading regime can lead to permanent displacement accumulation at a lower rate than that of the one-way loading case, although it may cause a softer post-cyclic monotonic tensile response.