Assessing single-helix screw pile geometry on offshore installation and axial capacity

Due to their low-noise installation and relatively large axial capacity, screw piles have been proposed as an alternative foundation solution in dense sand for offshore renewable energy applications in deeper water. For this to occur, significant upscaling of onshore dimensions is required. Furthermore, the effects of certain geometric features on installation requirements are still not well understood. In this work, using the three-dimensional discrete-element method, the effects of base geometry, shaft diameter and helix pitch were investigated by simulating the full installation process prior to conducting axial compression and tension tests. The results of the investigation showed it is possible to optimise the geometry of the screw pile to reduce installation requirements, in terms of both vertical installation force (up to 61%) and installation torque (up to 39%), without reducing the axial capacity of the pile significantly.