Optimised design of screw anchors in tension in sand for renewable energy applications
Optimised design of screw anchors in tension in sand for renewable energy applications
The offshore deployment of floating offshore structures such as wind turbines or wave energy converters is expected to strongly increase during the next decade, to face the appetite for green energy sources. The growing size of these structures’ dimensions, inducing very large mooring forces, makes the anchoring solution adopted a critical issue for the commercial success of floating marine energy farms. The upscaling of the screw anchor technology from onshore to the offshore environment has been recently proposed as an efficient way of providing a large tension capacity while their installation generates far less noise and vibrations than impact pile driving. Most of recent studies on screw anchors have focused on separated geotechnical problems such as their uplift capacity or installation requirements. This paper incorporates within a single procedure geotechnical and structural constraints to calculate the optimal anchor geometry able to maximise the uplift capacity available. Performance envelopes for screw anchors have been derived in a parametric study, covering a broad range of soil conditions as well as in a case study, representative of offshore conditions. Results show that single screw anchors are more efficient (e.g. shorter and lighter) than driven piles to sustain tension loading. The results presented in this study support the applicability of screw anchors to be used as part of the mooring system for wave energy converters. However, tension requirements for tension-leg platform wind turbines would probably require the use of group of anchors.
Sand, Screw anchor, Screw piles, Torque
Cerfontaine, Benjamin
0730daf4-9d6b-4f2d-a848-a3fc54505a02
Knappett, Jonathan
cda30027-553d-4310-8a05-e48d8989a545
Brown, Michael
a653384d-4fa7-4987-b03c-8a6ce153c6e7
Davidson, Craig
972704f2-5a32-4469-ad4f-358c60ef8de2
Sharif, Yaseen
f8ed0802-9644-479f-b288-77dec7624aa8
1 December 2020
Cerfontaine, Benjamin
0730daf4-9d6b-4f2d-a848-a3fc54505a02
Knappett, Jonathan
cda30027-553d-4310-8a05-e48d8989a545
Brown, Michael
a653384d-4fa7-4987-b03c-8a6ce153c6e7
Davidson, Craig
972704f2-5a32-4469-ad4f-358c60ef8de2
Sharif, Yaseen
f8ed0802-9644-479f-b288-77dec7624aa8
Cerfontaine, Benjamin, Knappett, Jonathan, Brown, Michael, Davidson, Craig and Sharif, Yaseen
(2020)
Optimised design of screw anchors in tension in sand for renewable energy applications.
Ocean Engineering, 217, [108010].
(doi:10.1016/j.oceaneng.2020.108010).
Abstract
The offshore deployment of floating offshore structures such as wind turbines or wave energy converters is expected to strongly increase during the next decade, to face the appetite for green energy sources. The growing size of these structures’ dimensions, inducing very large mooring forces, makes the anchoring solution adopted a critical issue for the commercial success of floating marine energy farms. The upscaling of the screw anchor technology from onshore to the offshore environment has been recently proposed as an efficient way of providing a large tension capacity while their installation generates far less noise and vibrations than impact pile driving. Most of recent studies on screw anchors have focused on separated geotechnical problems such as their uplift capacity or installation requirements. This paper incorporates within a single procedure geotechnical and structural constraints to calculate the optimal anchor geometry able to maximise the uplift capacity available. Performance envelopes for screw anchors have been derived in a parametric study, covering a broad range of soil conditions as well as in a case study, representative of offshore conditions. Results show that single screw anchors are more efficient (e.g. shorter and lighter) than driven piles to sustain tension loading. The results presented in this study support the applicability of screw anchors to be used as part of the mooring system for wave energy converters. However, tension requirements for tension-leg platform wind turbines would probably require the use of group of anchors.
Text
Ocean_Engineering_2020
- Accepted Manuscript
More information
Accepted/In Press date: 24 August 2020
e-pub ahead of print date: 10 October 2020
Published date: 1 December 2020
Additional Information:
Funding Information:
This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 753156. The authors would also like to acknowledge the support of EPSRC (Grant no. EP/N006054/1 : Supergen Wind Hub: Grand Challenges Project: Screw piles for wind energy foundations).
Publisher Copyright:
© 2020 Elsevier Ltd
Keywords:
Sand, Screw anchor, Screw piles, Torque
Identifiers
Local EPrints ID: 444162
URI: http://eprints.soton.ac.uk/id/eprint/444162
ISSN: 0029-8018
PURE UUID: 1a39c72b-e06d-4cbe-a0d7-aa3c0ab8966b
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Date deposited: 29 Sep 2020 17:40
Last modified: 22 Oct 2022 04:01
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Author:
Jonathan Knappett
Author:
Michael Brown
Author:
Craig Davidson
Author:
Yaseen Sharif
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