Whole-life modelling of anchor capacity for floating systems: the RSN–CSI approach
Whole-life modelling of anchor capacity for floating systems: the RSN–CSI approach
Successive episodes of cyclic loading cause the strength of soft soils to reduce, through pore pressure build-up, and then recover, through consolidation, as shown by model testing, field studies and theoretical considerations. These ‘whole-life’ changes in soil strength affect the capacity of anchoring systems for offshore infrastructure such as floating turbines or platforms. This paper introduces a new macro-model for assessing the through-life changes in seabed strength and anchor capacity as a result of variable cyclic loading and concurrent consolidation. The model combines SN curves for damage accumulation with a critical state soil mechanics framework for changes in soil strength and anchor capacity. These methods allow the full operational lifetime of an anchoring system to be rapidly analysed, encompassing timescales from individual wave-induced load cycles, through to annual seasons and soil consolidation processes. The approach provides a new basis for whole-life modelling of anchoring systems that is sufficiently fast to allow reliability-based assessments via a Monte Carlo method. In soft soils that exhibit beneficial gains in capacity, this method provides a basis for more efficient design through reductions in anchor size.
Anchors and foundations, Floating offshore renewable energy, Offshore geotechnics, Whole-life geotechnics
Kwa, K.A.
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White, D. J.
a986033d-d26d-4419-a3f3-20dc54efce93
Tosdevin, T.
89dd4167-7c3b-4b26-a8a8-9c94d0d45d53
Jin, S.
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Greaves, D.
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1 August 2023
Kwa, K.A.
18faee0d-75d9-4683-a2c8-604625eecbb0
White, D. J.
a986033d-d26d-4419-a3f3-20dc54efce93
Tosdevin, T.
89dd4167-7c3b-4b26-a8a8-9c94d0d45d53
Jin, S.
1c4c93d5-5275-4394-a14f-c1ed352824cb
Greaves, D.
0ec94618-5a7d-4e26-8f24-500997540d1c
Kwa, K.A., White, D. J., Tosdevin, T., Jin, S. and Greaves, D.
(2023)
Whole-life modelling of anchor capacity for floating systems: the RSN–CSI approach.
Applied Ocean Research, 138, [103671].
(doi:10.1016/j.apor.2023.103671).
Abstract
Successive episodes of cyclic loading cause the strength of soft soils to reduce, through pore pressure build-up, and then recover, through consolidation, as shown by model testing, field studies and theoretical considerations. These ‘whole-life’ changes in soil strength affect the capacity of anchoring systems for offshore infrastructure such as floating turbines or platforms. This paper introduces a new macro-model for assessing the through-life changes in seabed strength and anchor capacity as a result of variable cyclic loading and concurrent consolidation. The model combines SN curves for damage accumulation with a critical state soil mechanics framework for changes in soil strength and anchor capacity. These methods allow the full operational lifetime of an anchoring system to be rapidly analysed, encompassing timescales from individual wave-induced load cycles, through to annual seasons and soil consolidation processes. The approach provides a new basis for whole-life modelling of anchoring systems that is sufficiently fast to allow reliability-based assessments via a Monte Carlo method. In soft soils that exhibit beneficial gains in capacity, this method provides a basis for more efficient design through reductions in anchor size.
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More information
Accepted/In Press date: 13 July 2023
e-pub ahead of print date: 1 August 2023
Published date: 1 August 2023
Additional Information:
Funding Information:
This work forms part of research supported by the EPSRC Supergen Offshore Renewable Energy (ORE) Hub (Grant EPSRC EP/S000747/1) and by the Royal Academy of Engineering under the Research Fellowship Programme and the RAEng Chair in Emerging Technologies Centre of Excellence in Intelligent & Resilient Ocean Engineering (IROE).
Keywords:
Anchors and foundations, Floating offshore renewable energy, Offshore geotechnics, Whole-life geotechnics
Identifiers
Local EPrints ID: 481703
URI: http://eprints.soton.ac.uk/id/eprint/481703
ISSN: 0141-1187
PURE UUID: a7e9d00c-581c-48e2-9ab5-f402c0c84e8d
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Date deposited: 06 Sep 2023 16:50
Last modified: 18 Mar 2024 03:52
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Contributors
Author:
T. Tosdevin
Author:
S. Jin
Author:
D. Greaves
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