Bridge Reliability Assessment Based on Monitoring

During the past decade, monitoring concepts for structural systems have been subjected to a rapid development process. They have become more and more important in the intervention planning (e.g., maintenance, repair, rehabilitation, replacement) on new and existing structures. Nevertheless, there is still a strong need for the efficient use of structural monitoring data in the reliability assessment and prediction models. Updating prediction models, based on monitoring data, affect the intervention strategies. Since these strategies involve costs, monitoring systems assist the efficient spending of available budgets. Therefore, the demand for the efficient use of monitoring data is not only related to structural reliability, but also to cost aspects. In an extended sense, structural monitoring can be considered similar to quality assurance and acceptance sampling, since it is not practically possible to continuously monitor all performance indicators in all critical sections of an entire structural system. Nevertheless, the continuous and simultaneous measurements at discrete points of a deteriorating structural system, as provided by monitoring, allow the assessment of the performance of a structure with respect to different limit states. The aim of this paper is twofold: (a) To present an approach for the efficient inclusion of monitoring data in the structural reliability assessment process; and (b) to demonstrate the use of monitored data for the development of prediction models. The approach is illustrated on an existing highway bridge (the Lehigh River Bridge SR-33), a structure located in Pennsylvania and monitored by the Advanced Technology for Large Structural Systems Center, a National Engineering Research Center at Lehigh University.