Turning Telecommunication Fiber-Optic Cables into Distributed Acoustic Sensors for Vibration-Based Bridge Health Monitoring

We introduce a nondedicated bridge health monitoring (BHM) system that turns pre-existing telecommunication fiber-optic cables into distributed acoustic sensors to collect dynamic strain responses. Due extensively installed fiber in the cities, our cable-based enables efficient and low-cost BHM without requirement of on-site sensor installation maintenance; however, it is challenging extract damage-sensitive information (e.g., natural frequencies mode shapes) from this data as has large measurement noise error propagation. To overcome challenge, we develop physics-guided identification method models shapes based on parametric shape functions derived dynamics. then estimate displacement function by analytically double-integrating modeled shape. Our improves accuracy estimating features reduces propagation constraining with evaluated concrete continuous three-span San Jose, California. successfully identified first three reconstructed meter-scale resolution.