ABSTRACT
Rural bridges in the U.S. are aging and a lack of resources motivate owners to explore cost-effective approaches for detecting deficiencies across their inventory. Integrating automated structural health monitoring and damage location and classification methods, ones that do not require extensive financial or human capital, could help rural bridge owners better manage their limited resources to maintain safe operations. Ongoing research is examining the effectiveness with which optimized sensor nets and Proper Orthogonal Decomposition (POD) identify and locate damage on rural bridges. Three similar simply supported bridges, consisting of steel beams supporting a concrete deck, were tested prior to their demolition and replacement. Strain time histories were recorded when a vehicle of known weight crossed each bridge in different directions and at different speeds. The effectiveness with which the developed POD based methodology detected damage was evaluated by progressively damaging beam flanges and webs on each bridge. Snapshot matrices of structural response measured by the sensors helped create Proper Orthogonal Modes (POMs) for each damage level and corresponding moving load tests. The accuracy with which the POMs identified damage locations and their sensitivity to vehicle location and direction were evaluated.
