Fiber Optic Strain Monitoring for Long-Term Evaluation of a Concrete Footbridge Under Extended Test Conditionss

An optical fiber sensor system that can be installed and used to give reliable and informative data has been developed, tested, and evaluated, over an extended period of two years, on a redundant 50-year-old concrete footbridge whose conditions of use were well known. The bridge now serves as an operational test-bed as it has been taken out of service, and recently has been subjected to different known environmental and loading conditions. Thus in this paper, specific and controlled damage is induced, the effects are monitored, and thus the changes induced to the bridge are recorded, using the optical fiber sensor system over the test period. During this two-year survey, issues relating to the installation, use, data capture, and evaluation of performance not available in the present literature have been identified and addressed giving valuable information for the long-term evaluation on the installation and use of optical sensors to assess better such concrete structures.