Embedded Fiber-optic Sensing for Low-cost, High Resolution Monitoring in Bridges and Critical Structures

Under a collaboration led and funded by VicTrack, VicRoads, and other Victorian State agencies with funding from the Victoria Public Sector Innovation Fund (PSIF) in Australia, the Palo Alto Research Center (PARC) and University of Melbourne (UoM) are developing Fibridge (overseen by a Project Governance Board chaired by VicTrack), a fiber-optic (FO) smart monitoring system for bridges to enable predictive maintenance using the industrial internet of things (IIoT). The system uses FO sensors attached to bridge structures to accurately measure and estimate parameters indicative of bridge state online, such as structural strain, thermal response, bending moments, shear/impact loads, and corrosion. Fibridge leverages PARC’s low-cost, highresolution, compact wavelength-shift detection technology and intelligent algorithms in combination with UoM and the stakeholder team’s structural engineering know-how to enable effective real-time monitoring, performance management, better reliability, improved safety, and optimized bridge design. While Fibridge is initially targeting road and rail bridges, it will be extendable to other structures with similar maintenance/monitoring pain points. Here we present an overview of the project, enabling technologies, and summarize key results on vehicle load and structural response features detectable, bridge state estimation algorithm development, low-cost optical readout development, and validation test results. An initial proof-of-concept demonstration on a VicRoads highway bridge in Melbourne being monitored with FO sensors has shown promise thus far. At this stage, the technology is being scaled up towards an extended pilot trial on multiple rail, road, and transit bridges in Victoria. A business case for Fibridge to enable cost-effective maintenance is also summarized.