Optimal next inspection time for bridges based on corrosion deterioration

As the transportation demands grow rapidly, and some vehicle bridges show corrosion degradation, systematic and life-cycle based procedures may help to schedule cost-effective maintenance programs. In this paper a reliability-based formulation is proposed for prediction of the next bridge inspection time on the basis of corrosion evolution prediction. Given unknown characteristics on the corrosion initiation time, the epistemic uncertainty on this parameter is explicitly included. For bridges where little or no follow up has been previously made, the characterization of damage state and the bridge integrity state contains a great deal of epistemic uncertainty. The impact that this epistemic uncertainty has on the identification of corrosion initiation time is appraised in order to estimate the cost/benefit of making additional studies that may contribute to improve the corrosion initiation time and the overall bridge safety assessment. The limit state and structural reliability of the bridge is calculated in terms of a damage index that depends on the bridge corrosion evolution and the consequent reduction on moment capacity. As a consequence, the bridge failure probability evolves. The acceptable failure probability is calculated as a function of the expected losses and it is used as the safety threshold; whenever the bridge failure probability goes below the acceptable value, marks the proper time to perform the next bridge inspection.

Life-Cycle and Sustainability of Civil Infrastructure Systems - Proceedings of the 3rd International Symposium on Life-Cycle Civil Engineering, IALCCE 2012

De Len, D., Gonzlez-Prez, C., Bisadi, V., Gardoni, P., Head, M., & Hurlebaus, S.

Optimal next inspection time for bridges based on corrosion deterioration Conference Paper