Physical modelling of screw piles for offshore wind energy foundations

Using existing design methodologies, a series of screw piles were designed to meet the loads required for an upper-bound design scenario of a steel jacket supported offshore wind turbine in deep water. The installation torque and force were measured from centrifuge tests of 1/80 th scale models of the screw piles in very dense sand. Results indicate that the installation requirements are significant and may be beyond the capabilities of existing conventional installation equipment. Optimisation of the screw pile design was successful in reducing the installation force and torque by 34 and 17% respectively over the non-optimised design variant. Accurate prediction of the installation torque is critical and can be achieved using correlations with cone penetration test data