Distributed Optical Fiber-Based Monitoring of Smart Passive Anchors for Soil Stabilization

Geotechnical structures, such as piles and anchors, play a critical role in providing stability and support in a wide range of civil engineering applications. Ensuring the integrity and safety of these structures and reliably understanding their structural behavior are of paramount importance. This paper explores the application of distributed fiber optic sensors (DFOS) as a cutting-edge technology for monitoring the performance and health of passive composite anchors for soil stabilization. These anchors comprise a conventional carbon steel self-drilling bar with one or more embedded harmonic steel tendons, cemented within the central cavity of the bar. The system is finalized by an external plate for securing the bar and a protective cover for safeguarding the tendon head. Within this context, DFOS technology offers a non-invasive and cost-effective solution for real-time monitoring of various parameters, such as strain and temperature, along the entire length of the fiber optic cable. This technology enables continuous, high-resolution monitoring data collection, providing a comprehensive understanding of the long-term behavior of this specific geotechnical structure. The capability of DFOS to provide spatially distributed information facilitates the detection of localized stress concentrations and deformation patterns. The paper covers some practical considerations, such as installation techniques, data analysis and preliminary results on recently case study. The limitations and challenges associated with DFOS technology in geotechnical applications will be also discussed, including the need for specialized expertise in interpreting the data, the potential for signal attenuation in long cables and the particular care that these sensors require during cable installation and management.