On Population-based structural health monitoring for bridges

The maintenance and repair of bridges (and other large scale infrastructure projects)is a major area which could benet from Structural Health Monitoring technology. Inspections on bridges can take a long time and require many people, and are thereforeconducted infrequently. This low frequency of inspection leaves the chance tha tdamage and dangerous critical failures can occur during the long timeframes betweeninspections. It might even be the case that an inspection fails to identify sub-surface damage. Therefore some form of continuous monitoring is desirable, especially if suchsystems can reliably detect sub-surface damage. However, the application of SHM to bridges is made challenging by the cost andpracticability of obtaining damage-state data for bridges. Over the lifetime of a singlebridge, it is hoped that a critical failure will never occur, and only a small number ofthe possible damage states will occur. It is also unpractical to intentionally damagestructures to obtain damage-state data.Population-based structural health monitoring seeks to overcome the obstacle of thelimited data available for a single structure, by allowing data to be shared betweensimilar structures. Bridges represent an interesting challenge for PBSHM as eachbridge is unique. As such, an assessment of how similar bridges are to each other isrequired. To provide this assessment, one must develop an abstract representation foreach bridge, and using this to perform a comparison.This paper describes the use of a general approach for assessing the similarity ofstructures, applied to several bridge examples which are representative of commontypes of bridges, to show that it can be applied in this field.