Life-cycle performance of structures: combining expert judgment and results of inspection

Life-Cycle Civil Engineering – Biondini & Frangopol

Current bridge management systems base decisions on the results of visual inspections. These systems consider visual inspection results as accurate and disregard any further information available. In the present study, the result of each inspection is considered as a random variable, dependent of a wide range of factors, that can be integrated with other sources of information, including expert judgment and results of other inspections. The combination of different sources of information results in reliable posterior information and allows more accurate predictions of future deterioration. In the present paper, performance of an existing structure is obtained in terms of the condition index, which describes the effects of deterioration as can be seen by an inspector, and the safety index, which measures the safety margin of the structure. The reduction in uncertainty associated with periodical inspections is considered through updating of performance profiles. The updating of the condition index is direct, as new information on this parameter is collected by the inspector. In terms of safety, however, only indirect information is collected and the uncertainty reduction associated with an inspection is significantly lower. Several realistic examples show the impact of inspections on the predicted life-cycle performance of structures.

UNIC - Research Center in the New University of Lisbon