Ross, E. and Randell, D. and Astrup, O.C. and Bitner-Gregersen, E. and Vanem, E. and Bunn, N. and Gouldby, B. and Liu, Y. and Feld, G. and Huseby, A. and Jonathan, Philip (2019) On environmental contours for marine and coastal design. In: Proceedings of the 38th International Conference on Ocean, Offshore & Arctic Engineering :. ASME, GBR. ISBN 9780791858851
Abstract
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 to identify environmental conditions giving rise to extreme structural loads and responses. There are different approaches to estimating environmental contours, some directly linked to methods of structural reliability. Each contouring approach has its pros and cons. Although procedures for applying contours in design have been reported in articles and standards, there is still ambiguity about detail, and the practitioner has considerable flexibility in applying contours. It is not always clear how to estimate environmental contours well. Over four years, DNV-GL, Shell, the University of Oslo and HR Walling-ford worked together to review current practice regarding the use of design contours. In this paper, we present a summary of our findings. We overview the motivations for different approaches to contours, and their resulting characteristics. Using different marine applications, we also explore the various sources of uncertainty present, their impact on contour estimates and the estimation of extreme environmental loads and responses.