Distributed Fiber Optic Sensing in Bridge Structural Health Monitoring: Insights from Real-Life Implementations in Germany

This study presents the application of distributed fiber optic sensing (DFOS) for structural health monitoring (SHM) of existing bridge structures in Germany. Using Rayleigh and Raman backscatter technologies, DFOS enables continuous strain measurements along entire structural segments with a high spatial resolution, surpassing conventional point-based sensing. This approach facilitates detailed strain evolution monitoring, early detection of localized damage, and identification of emerging risk zones, providing a valuable tool for authorities responsible for maintenance of the infrastructure. The research focuses on long-term monitoring of crack width variations in concrete structures, particularly those affected by stress corrosion cracking (SCC) and alkali-aggregate reaction (AAR). Insights are drawn from real-world applications across three bridge structures, including road and railway bridges. The findings highlight the advantages of DFOS in detecting progressive structural deterioration and enhancing maintenance strategies.