A Rational Procedure for Determination of Directional Individual Design Wave Heights

• Main Authors: Sterndorff, M., Sørensen, John Dalsgaard
• Other Authors: Chakrabarti, Subrata K.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Society of Mechanical Engineers 2001
• Subjects: Significant wave heights; Arctic
• Online Access: https://vbn.aau.dk/da/publications/96bf68d0-a869-11da-8341-000ea68e967b

For code-based LRFD and for reliability-based assessment of offshore structures such as steel platforms it is essential that consistent directional and omnidirectional probability distributions for the maximum significant wave height, the maximum individual wave height, and the maximum individual crest elevation are available. In Sørensen & Sterndorff (2000) stochastic models for the annual maximum values of the omnidirectional and directional significant wave heights, individual wave heights, and individual crest heights were presented. The models include dependencies between the maximum wave height from neighbouring directional sectors. Furthermore, the stochastic models include statistical uncertainties. The models were calibrated against data from the central part of the North Sea using the Maximum Likelihood method. In the present paper the stochastic models have been combined with a model for loading and response of offshore steel platforms. The resulting models have been used to derive consistent partial safety factors for LRFD-based design of wave loaded offshore structures. Design directional waves are then derived so that the desired reliability levels are obtained.