Physical modelling to demonstrate the feasibility of screw piles for offshore jacket supported wind energy structures

TY - JOUR

T1 - Physical modelling to demonstrate the feasibility of screw piles for offshore jacket supported wind energy structures

AU - Davidson, Craig

AU - Brown, Michael

AU - Cerfontaine, Benjamin

AU - Knappett, Jonathan

AU - Brennan, Andrew

AU - Al-Baghdadi, Therar

AU - Augarde, Charles

AU - Coombs, William M.

AU - Wang, Lei

AU - Blake, Anthony

AU - Richards, David

AU - Ball, Jonathan David

N1 - The authors would like to acknowledge the support of EPSRC (Grant no. EP/N006054/1: Supergen Wind Hub Grand Challenges Project: Screw piles for wind energy foundations). This project has also received support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 753156

PY - 2022/2

Y1 - 2022/2

N2 - Screw piles potentially offer quieter installation and enhanced axial tensile capacity over straight-shafted driven piles. As such, they have been suggested as a possible foundation solution for offshore jacket-supported wind turbines in deeper water. To investigate the feasibility of their use in this setting, centrifuge testing of six model screw piles of different designs was conducted to measure the installation requirements and ultimate axial capacity of the piles in very dense and medium-dense sand. The screw piles were designed to sustain loads generated by an extreme design scenario using published axial capacity and torque prediction formulae. Single- and double-helix designs, including an optimised design, intended to minimise installation requirements, with reduced geometry were installed and tested in-flight. Piles in the medium-dense sand, for example, had significant installation requirements of up to 18·4 MNm (torque) and 28·8 MN (vertical force), which were accurately predicted using correlations with cone resistance data (cone penetration test). Existing axial capacity design methods did not perform well for these large-scale screw piles, overestimating compressive and tensile capacities. Revised analytical methods for installation and axial capacity estimates are proposed here based on the centrifuge test results.

AB - Screw piles potentially offer quieter installation and enhanced axial tensile capacity over straight-shafted driven piles. As such, they have been suggested as a possible foundation solution for offshore jacket-supported wind turbines in deeper water. To investigate the feasibility of their use in this setting, centrifuge testing of six model screw piles of different designs was conducted to measure the installation requirements and ultimate axial capacity of the piles in very dense and medium-dense sand. The screw piles were designed to sustain loads generated by an extreme design scenario using published axial capacity and torque prediction formulae. Single- and double-helix designs, including an optimised design, intended to minimise installation requirements, with reduced geometry were installed and tested in-flight. Piles in the medium-dense sand, for example, had significant installation requirements of up to 18·4 MNm (torque) and 28·8 MN (vertical force), which were accurately predicted using correlations with cone resistance data (cone penetration test). Existing axial capacity design methods did not perform well for these large-scale screw piles, overestimating compressive and tensile capacities. Revised analytical methods for installation and axial capacity estimates are proposed here based on the centrifuge test results.

KW - Screw piles

KW - Offshore engineering

KW - Renewable energy

KW - Wind energy

KW - piles & piling

KW - offshore engineering

KW - torsion

UR - https://www.scopus.com/pages/publications/85119170690

U2 - 10.1680/jgeot.18.P.311

DO - 10.1680/jgeot.18.P.311

M3 - Article

SN - 0016-8505

VL - 72

SP - 108

EP - 126

JO - Geotechnique

JF - Geotechnique

IS - 2

T2 - 1st International Symposium on Screw Piles for Energy Applications

Y2 - 27 May 2019 through 28 May 2019

ER -