On environmental contours for marine and coastal design

Ross, E. and Astrup, O.C. and Bitner-Gregersen, E. and Bunn, N. and Feld, G. and Gouldby, B. and Huseby, A. and Liu, Y. and Randell, D. and Vanem, E. and Jonathan, Philip (2020) On environmental contours for marine and coastal design. Ocean Engineering, 195: 106194. ISSN 0029-8018

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Environmental contours are used in structural reliability analysis of marine and coastal structures as an approximate means to locate the boundary of the distribution of environmental variables, and hence sets of environmental conditions giving rise to extreme structural loads and responses. Outline guidance concerning the application of environmental contour methods is given in recent design guidelines from many organisations. However there is lack of clarity concerning (a) the differences between approaches to environmental contour estimation reported in the literature, and (b) the relationship between the environmental contour, corresponding to some return period, and the extreme structural response for the same period. Hence there is uncertainty about precisely when environmental contours should be used, and how they should be used well. This article seeks to provide some assistance in understanding the fundamental issues regarding environmental contours and their use in structural reliability analysis. Approaches to estimating the joint distribution of environmental variables, and to estimating environmental contours based on that distribution, are described. Simple freely-available software for estimation of the joint distribution, and hence environmental contours, is illustrated. Extra assumptions required to relate the characteristics of environmental contours to structural failure are outlined. Alternative response-based methods not requiring environmental contours are summarised. The results of an informal survey of the metocean user community regarding environmental contours are presented. Finally, recommendations about when and how environmental contour methods should be used are made.

Item Type:
Journal Article
Journal or Publication Title:
Ocean Engineering
Additional Information:
This is the author’s version of a work that was accepted for publication in Ocean Engineering. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Ocean Engineering, 195, 2020 DOI: 10.1016/j.oceaneng.2019.106194
Uncontrolled Keywords:
?? ocean engineeringenvironmental engineering ??
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Deposited On:
03 Mar 2020 09:30
Last Modified:
15 Jul 2024 19:21