Bridge Monitoring Using Brillouin Fiber-Optic Sensors

We report the results of a static load test performed on a road-bridge with a span length of 44.40 m. The tests were performed by a portable prototype instrument exploiting stimulated Brillouin scattering in optical fibers for deformation and temperature measurements. The optical fiber sensor was able to provide the strain distribution along a supporting beam of the bridge with a spatial resolution of 3 meters and a strain resolution of ±15 με. Comparison of fiber-optic measurements with finite-elements-method (FEM) simulations, as well as with data collected by vibrating wire strain gauges, confirmed the validity of the SBS-based approach in monitoring the deformation of large structures.