Railroad infrastructure management enabled by structural health monitoring

To increase overall profitability, add capacity to rail operations, and comply with new federal regulations on bridge safety, North American railroads are exploring means to improve the management of their bridge networks. Current maintenance, repair, and replacement (MRR) decisions are informed by bridge inspections and ratings, which recommend observing the response of bridges under trains. However, an objective relationship between bridge responses, bridge service state condition, and impact to railroad operations has yet to be established. Better determining the consequences of MRR decisions will allow railroads to effectively allocate their limited resources. This paper develops an approach for consequence-based management of bridge networks, employing fragility curves to relate service condition limit-states to bridge displacement. The operational costs associated with these service conditions can be used to estimate the total costs of a given MRR policy. This framework provides a consistent approach for the prioritization of railroad bridge MRR decisions.