Sequential Bayesian updating for time-variant reliability analysis of ageing structures

This paper proposes a new method for time-variant reliability analysis of existing ageing structures under epistemic uncertainty from limited recurrent field measurement data. A growth model and a noise factor are introduced to account for the ageing changes of distribution parameters that take place while the reliability interval is sequentially updated using inspection data acquired over the service period. The method is applied to quantify the reliability of deteriorating concrete bridges under routine inspections of reinforcement steel corrosion. The interval estimation of corrosion and reliability shows narrower uncertainty bounds than a traditional frequentist approach, particularly when relatively sparse inspection datasets are available. In the case study presented, the relative variation of reliability bounds could be reduced by at least half when compared to a frequentist estimation.