Whole-life assessment of subsea shallow foundation capacity
Whole-life assessment of subsea shallow foundation capacity
Geotechnical design of subsea shallow foundations is typically based on in situ seabed strength reduced to take account of cyclic load degradation, in conjunction with the peak design load. This design philosophy emerged for fixed structures, designed to survive storms. However, subsea shallow foundation loading sequences and the associated seabed response differ significantly from that for fixed structures. They have periods that are orders of magnitude longer than storm loading, allowing for excess pore pressure dissipation during or between loading cycles that can lead to cyclic hardening rather than cyclic degradation of the supporting seabed. In addition, an alternative philosophy of tolerable mobility allows design loads that result from expansions or misalignments to be relieved if the foundation can displace and the soil-structure interaction be quantified. Greater scrutiny of the whole-life loading, soil-structure interaction and the associated seabed response can lead to efficiencies in foundation footprint, easing installability and reducing cost. This paper describes this ‘staircase’ of improvements in subsea shallow foundation design philosophy that are being explored in the ARC Research Hub for Offshore Floating Facilities, and provides examples to support the ideas presented.
Gourvenec, S.
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Stainer, S.A.
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White, D.A.
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Morgan, N.
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Banimahd, M.
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Chen, J.
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September 2017
Gourvenec, S.
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Stainer, S.A.
33d6e9b0-376d-43d1-9ae3-fab54ca87c35
White, D.A.
a986033d-d26d-4419-a3f3-20dc54efce93
Morgan, N.
6fe647e9-8cfe-455b-abfb-149b0268fef5
Banimahd, M.
2c36a641-a003-48bd-aebf-21504c0605f3
Chen, J.
81b16c82-3493-4164-8bdc-0b9f0e9415f9
Gourvenec, S., Stainer, S.A., White, D.A., Morgan, N., Banimahd, M. and Chen, J.
(2017)
Whole-life assessment of subsea shallow foundation capacity.
Offshore Site Investigation and Geotechnics 2017, , London, United Kingdom.
12 - 14 Sep 2017.
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Conference or Workshop Item
(Paper)
Abstract
Geotechnical design of subsea shallow foundations is typically based on in situ seabed strength reduced to take account of cyclic load degradation, in conjunction with the peak design load. This design philosophy emerged for fixed structures, designed to survive storms. However, subsea shallow foundation loading sequences and the associated seabed response differ significantly from that for fixed structures. They have periods that are orders of magnitude longer than storm loading, allowing for excess pore pressure dissipation during or between loading cycles that can lead to cyclic hardening rather than cyclic degradation of the supporting seabed. In addition, an alternative philosophy of tolerable mobility allows design loads that result from expansions or misalignments to be relieved if the foundation can displace and the soil-structure interaction be quantified. Greater scrutiny of the whole-life loading, soil-structure interaction and the associated seabed response can lead to efficiencies in foundation footprint, easing installability and reducing cost. This paper describes this ‘staircase’ of improvements in subsea shallow foundation design philosophy that are being explored in the ARC Research Hub for Offshore Floating Facilities, and provides examples to support the ideas presented.
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Accepted/In Press date: 15 July 2017
Published date: September 2017
Venue - Dates:
Offshore Site Investigation and Geotechnics 2017, , London, United Kingdom, 2017-09-12 - 2017-09-14
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Local EPrints ID: 423068
URI: http://eprints.soton.ac.uk/id/eprint/423068
PURE UUID: 320e274f-8717-493c-b4a9-334ff8671076
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Date deposited: 13 Aug 2018 16:31
Last modified: 16 Mar 2024 04:32
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Contributors
Author:
S.A. Stainer
Author:
N. Morgan
Author:
M. Banimahd
Author:
J. Chen
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