Improving Distributed Fiber-Optic Sensor Measures by Digital Image Correlation: Two-Stage Structural Health Monitoring

This paper deals with the integrated use of distributed fiber-optic sensors and digital image correlation techniques to develop a two-stage monitoring method for damage detection, localization, and quantification. The proposed methodology was applied in the laboratory on reinforced concrete beam specimens and is suitable for further field developments in concrete structures of large dimensions. The first stage is based on distributed strain monitoring through Brillouin scattering-based fiber-optic sensors to detect and locate potential damage zones within the entire structure, while the second focuses on verification of the critical regions identified by the optical-fiber sensor using the digital image correlation technique

Structural health monitoring of in-service tunnels

This work presents an overview of some of the most promising technologies for the structural health monitoring (SHM) of in-service tunnels. The common goal of damage or unusual behaviour detection is best pursued by an integrated approach based on the concurrent deployment of multiple technologies. Typically, traditional SHM systems are installed in problematic or special areas of the tunnels, giving information on conditions and helping manage maintenance. However, these methodologies often have the drawbacks of forcing the interruption of traffic for SHM system installation and monitoring only selected portions. Alternative solutions that would make it possible to keep the tunnel in normal operation and/or to analyse the entire infrastructure development through successive and continuous scanning stages, would be beneficial. In this paper, the authors will briefly review some traditional monitoring technologies for tunnels. Furthermore, the work is aimed at identifying alternative solutions, limiting or avoiding traffic interruptions