ABSTRACT
This paper describes the development of an innovative, cost-effective system for real-time condition assessment of the Market Street Bridge after the completion of its rehabilitation. The 547-m long suspended steel bridge was originally constructed in 1905, and was undergone major rehabilitation work that was completed in November 2011. The sensory system deployed in this study continuously monitors the global structural displacements of the bridge towers under operating and environmental conditions. A detailed 3D finite element model was developed for the suspended part of the Market Street Bridge and the model response was validated versus the field measured data. A damage identification technique was developed through comparison of vibration characteristics of structural elements between two different states. One represents the initial and often undamaged state and the second represents the deteriorated state after damage. A nonlinear trend of the first natural frequency of the bridge structure was observed once the towers reach certain inclinations, which could be attributed to the change in bridge stiffness due to damage or plastic deformation. This system was found to be a cost-effective remote monitoring system that provides the foundation for an enhanced structural bridge management.
