Investigating and minimising the effects of torque generated during the installation of novel foundations for renewable energy applications

Lead Research Organisation: University of Dundee
Department Name: Science and Engineering Office

Abstract

There are currently significant installation costs associated with UK Round III offshore windfarm developments and future deployment in deeper water, which will require foundation solutions that are highly efficient, quick to install and avoid noise and vibration (to avoid impacts on marine mammals).

One solution is to use steel screw piles that are commonly used onshore and scale them up for full scale deployment. Unfortunately, though there are potentially significant issues with the installation torque and force requirements of these geometries, which mean accurate torque and force prediction models are required to feed into design decisions such as at what water depth group deployment is preferable to individual piles (group efficiency, coupled with more smaller piles resulting in lower installation requirements). There is ongoing work looking at some of these question in sands but little attention has been given to how these problems can be overcome in clay. This project will expand existing work undertaken in sand and investigate if this can be applied in clay soils.

Aims and objectives:
1, Development of reliable screw pile torque/force installation requirement prediction tools for different pile geometries.

2, Understanding the effect of group screw pile installation on both torque/force requirements and pile interaction efficiency.

3, Investigate novel solutions to installation torque/force reduction (e.g. torque plus vibration installation) and how these can be incorporated in pile geometry optimisation and installation plant development.

4, Develop tools to predict installation requirements and in-service screw pile performance in clay based upon standard field insitu investigation techniques.

Research methodology:

1, Specialist physical modelling facilities will be used to investigate the effect of individual and group installation effects on torque/force requirements, in-service pile performance and to develop insitu test based design techniques. These systems will allow realistic simulation of the installation process and will be developed in this project to allow the piles to be subject to cyclic loading.

2, Investigation of group effects using numerical (finite element, FE) simulation will be developed to allow a wide range of situations to be modelled in an efficient manner with validation against scale model testing.

3, Computational Discrete Element Modelling (DEM) coupled with Finite Element Analysis will also be developed in a novel application of these computational techniques to the difficult problem of rotating and pushing an object. This process will be validated against the physical modelling and in-service pile performance compared to FE techniques that cannot easily model installation.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R512473/1 01/10/2017 30/09/2021
1950239 Studentship EP/R512473/1 01/10/2017 30/09/2021 Yaseen Umar Sharif
 
Description Through the use of new numerical techniques, it has been found that the current guidance on installation of screw piles is incorrect and we are able to minimise the installation requirements of large diameter foundations and increasing the capacity. This reduces the material cost associated with the pile size and reduces the need for extremely large installation equipment to be developed for use offshore.
Exploitation Route The outcomes of the funding will have a direct effect on industrial application for the design and deployment of screw piles for use as foundation for offshore renewable resources.
The outcome can also be used to update current guidance on installation requirements of screw piles
Sectors Construction

 
Description The findings from my work have been used by an industrial company to further their research into the design of their installation vessel for offshore installation of screw piles. The results of the study so far have reduced the material requirements of the pile and potentially reduced the size of vessel required to install the pile.
First Year Of Impact 2019
Sector Construction
Impact Types Economic