Development of driveability model for piles for offshore wind turbines

Student thesis: Master thesis (including HD thesis)

  • Mads Helsager Harpøth
4. term, Structural and Civil Engineering, Master (Master Programme)
This project contains a study of driveability analysis of offshore monopiles driven in sands, which identifies the key components, methods and models involved. The most commonly applied computer program used in these predictions is not truly dynamic and uses some assumptions which may not be appropriate for all situations. An input to the program, the static resistance to driving (SRD), along with a set of parameters relating the resistance to the stiffness and damping within the soil, are not uniquely defined. A thorough investigation into various SRD models is performed, which finds that the models are all semi-empirical and that they can not be expected to be reliable for conditions dissimilar to the conditions from which they were derived. A fully dynamic model seeking to overcome some of the simplifications, using three different discretization regimes for pile, side friction and tip resistance, and using a more advanced transient solving algorithm is developed and tested for sensitivity to model parameters. The SRD models are applied within the model to investigate their ability to reproduce an available driving record from a pile installed in the North Sea, and large variations in accuracy are found.
Publication date8 Jun 2017
Number of pages157
ID: 259411722