Reliability-based methods in the inspection planning of fixed offshore steel structures

摘要

For the continued safe operation of a fixed offshore steel structure, it is necessary for any damage resulting from fatigue, collision or impact to be prevented from leading to either progressive failure or sudden collapse. The detection of fatigue damage at an early stage in the life of the structure is, however, difficult and costly, especially sub-sea, but the financial and human consequences of structural failure resulting from inadequate inspection are likely to be much greater, and need to be prevented. The paper describes research that has been undertaken to enable sub-sea inspection strategies to be improved. The findings relate the inspection methods used, the locations inspected and the frequency of inspection to the probability of local fatigue damage leading to unacceptable structural consequences. This provides a practical way of targeting offshore inspection in order to reduce overall life-cycle costs whilst maintaining adequate levels of system reliability for the complete structure.