In recent years there has been considerable development in the area of system reliability assessments of offshore structures except for jack-up platform. However, since the reliability of jack-up platform is a crucial aspect with regard to the safety of the structure during its service time and possibly beyond the predicted lifetime, there is significant demand from the offshore industry to investigate system reliability of this type of offshore structure. This paper therefore presents a methodology to estimate the system reliability of jack-up structures by considering sequence of fatigue failure. First, component reliability of this structure based on fatigue limit state function is derived, and then the branch and bound technique has been used to identify an important sequence of section failure leading to system collapse. The structural failure is therefore regarded as the event at which one of these important sequences occurs. The result determined for a jack-up structure shows a significant systems effect and that the probability of structural failure is larger than the probability of failure for an individual section.
展开▼
