Corrosion estimation of a historic truss bridge using model updating

Bridge structures are valuable national assets for transportation and economy that should be maintained properly for continuous stable operation. Corrosion is common in steel bridges; severe corrosion may result in significant economic impact and long downtime for retrofit. To date, various corrosion evaluation technologies have been developed such as nondestructive evaluation techniques and analytical model updating strategies. Among them, nondestructive evaluation is costly and time consuming for scanning entire bridges. For model updating, few examples on full-scale bridges with severe corrosion have been reported. In this paper, the corrosion level in a historic steel-truss bridge is estimated using model updating. Dynamic characteristics of the bridge are identified via a series of short-term full-scale experiments. An initial finite-element model of this bridge is then updated to match the field corrosion estimation results. The corrosion levels predicted by the proposed approach were consistent with the results of a visual inspection of this bridge. The results of the model updating routine could be used to monitor the overall corrosion levels in the structure with periodic inspection over time.