Reliability based criteria for fixed steel offshore platforms
The key issue addressed in this paper is the accuracy of structural reliability models for the case of fixed steel offshore structures under extreme storm loading. The emphasis is on engineering accuracy for the purpose of use in decision-making and more specifically to achieve and demonstrate sufficient accuracy to enable the use of reliability models in deriving design criteria for fixed offshore platforms. The long term distributions of environmental loading derived by Shell for various geographical areas are re-started in terms of more commonly used probability distributions to enable a direct comparison with other results. The short term variability of maximum wave height and Base Shear within a sea-state (or a typical storm) is also re-stated in a form which allows useful conclusions with respect to wave force variability. Finally the modelling of and uncertainty in ultimate strength are addressed and conclusions are drawn with respect to the overall accuracy of the reliability predictions. These reliability models are subsequently used to derive partial load factors for use in conjunction with API LRFD to achieve a target reliability level, appropriate for permanently manned installations. These load factors are location dependent. Further load factors are proposed for the design of new, not normally manned installations.
- OSTI ID:
- 449658
- Report Number(s):
- CONF-9606279--; ISBN 0-7918-1490-4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nonlinear ultimate strength analysis of fixed offshore platforms for earthquake environments
Risk analysis methodology for developing design and assessment criteria for fixed offshore structures