Optimised screw pile design for offshore jacket foundations in medium–dense sand
Optimised screw pile design for offshore jacket foundations in medium–dense sand
Screw piles are well-suited foundations for offshore jacket structures, as they can be installed without significant underwater noise and have a large axial capacity. However, installation requirements for such large piles must be reduced to enable their installation in the field. This study combines geometry and installation optimisation to lower force and torque installation requirements. An original pile geometry, composed of a large diameter upper section connected to a smaller diameter lower section by a transition piece, was tested in a geotechnical beam centrifuge. The advancement ratio (AR), describing the relative vertical movement per pile rotation, was varied below the threshold usually recommended. The results show that a low AR reduces the pile penetration resistance and even generates some pull-in, while the torque remains almost unaffected. The torque is mainly associated with the upper section of the pile, which has a greater diameter to resist lateral loading in service. The pile capacity in tension generally increases as AR is reduced and reaches a maximum for AR = 0·5, while the compressive capacity reduces. It was shown that a simplified method can be used to estimate pile capacity, providing that some AR-dependent reduction factors can be calculated or assumed.
anchors & anchorages, centrifuge modelling, offshore engineering
114-119
Cerfontaine, B.
0730daf4-9d6b-4f2d-a848-a3fc54505a02
Brown, M. J.
082bfde0-432f-4399-9d0d-00968fde3229
Davidson, C.
5851ec44-4bec-41ed-85d0-fa19f958b8d4
Sharif, Y. U.
d1b8387c-6287-4ceb-8134-9037b3a8df8d
Huisman, M.
fb44d706-adb8-4655-9624-ebfbd6cdf4f4
Ottolini, M.
3eccb879-6dbd-4049-96f1-39cffbd9733f
June 2022
Cerfontaine, B.
0730daf4-9d6b-4f2d-a848-a3fc54505a02
Brown, M. J.
082bfde0-432f-4399-9d0d-00968fde3229
Davidson, C.
5851ec44-4bec-41ed-85d0-fa19f958b8d4
Sharif, Y. U.
d1b8387c-6287-4ceb-8134-9037b3a8df8d
Huisman, M.
fb44d706-adb8-4655-9624-ebfbd6cdf4f4
Ottolini, M.
3eccb879-6dbd-4049-96f1-39cffbd9733f
Cerfontaine, B., Brown, M. J., Davidson, C., Sharif, Y. U., Huisman, M. and Ottolini, M.
(2022)
Optimised screw pile design for offshore jacket foundations in medium–dense sand.
Géotechnique Letters, 12 (2), .
(doi:10.1680/jgele.21.00105).
Abstract
Screw piles are well-suited foundations for offshore jacket structures, as they can be installed without significant underwater noise and have a large axial capacity. However, installation requirements for such large piles must be reduced to enable their installation in the field. This study combines geometry and installation optimisation to lower force and torque installation requirements. An original pile geometry, composed of a large diameter upper section connected to a smaller diameter lower section by a transition piece, was tested in a geotechnical beam centrifuge. The advancement ratio (AR), describing the relative vertical movement per pile rotation, was varied below the threshold usually recommended. The results show that a low AR reduces the pile penetration resistance and even generates some pull-in, while the torque remains almost unaffected. The torque is mainly associated with the upper section of the pile, which has a greater diameter to resist lateral loading in service. The pile capacity in tension generally increases as AR is reduced and reaches a maximum for AR = 0·5, while the compressive capacity reduces. It was shown that a simplified method can be used to estimate pile capacity, providing that some AR-dependent reduction factors can be calculated or assumed.
Text
GEOTL_Cerfontaine_shared_version
- Accepted Manuscript
More information
Accepted/In Press date: 28 February 2022
e-pub ahead of print date: 4 April 2022
Published date: June 2022
Additional Information:
Funding Information:
The authors acknowledge the support of the Engineering and Physical Science Research Council (EPSRC) (grant EP/N006054/1: Supergen Wind Hub Grand Challenges Project: Screw piles for wind energy foundations).
Publisher Copyright:
© 2022 ICE Publishing: all rights reserved.
Keywords:
anchors & anchorages, centrifuge modelling, offshore engineering
Identifiers
Local EPrints ID: 477402
URI: http://eprints.soton.ac.uk/id/eprint/477402
PURE UUID: 8af7f4aa-196d-4548-a149-93c265e02202
Catalogue record
Date deposited: 06 Jun 2023 16:33
Last modified: 17 Mar 2024 07:22
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Contributors
Author:
M. J. Brown
Author:
C. Davidson
Author:
Y. U. Sharif
Author:
M. Huisman
Author:
M. Ottolini
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