Factors in Bridge Failure, Inspection, and Maintenance

Currently there are around 14,000 bridges serving both major and minor transportation systems in Taiwan. Damages incurred to these bridges would surely affect the social and economic well-being of the society. In this study, after analyzing more than 900 pieces of data regarding bridges in Taiwan, it was found that in terms of overall bridge damage, bridges that have been in service 15 years or more, located farther from the ocean, and designed to resist seismic activities have a higher possibility to sustain overall structural damage; in comparison, bridges that have been in service 10 years or less, have more than four traffic lanes, and are designed as T-girder or I-girder are less prone to overall damage. In terms of severity of damage, bridges that are located farther from the ocean, crossing poor flow conditions, and possess a gravity type-deck are prone to more severe damage, while bridges designed as plate composite structures and possess asphalt concrete pavement are less prone to severe damage. In the life span of a bridge, the planning and design phase accounts for 4–6%, the construction phase 4–6%, and the service/maintenance phase 88–92%. It is clear that the maintenance of a bridge constitutes a major portion of the overall cost. Therefore, if managed well, periodic inspection and occasional retrofitting can reduce the life-cycle cost of a bridge project.