Distributed Fiber-Optic Sensors for Monitoring Slow Landslides and Anchors for Their Stabilization

Over the last few decades, both natural and man-made territories in Italy have shown great vulnerability due to the impact of climate change and the lack of maintenance of the territory itself. This makes it necessary to adopt surveillance and alert systems able to detect, in real time, the imminence of critical phenomena. In this context, optical fiber-based sensors are proving to be an innovative and appealing instrumentation in many applications due to their low cost-effectiveness and their possible large-scale use. In the geotechnical field, their employment in the monitoring of landslide deformation fields, or of elements interacting with landslides, has been tested both in the laboratory and at full scale. This paper presents two recent applications of distributed fiber-optic sensors on slow-moving landslides: in one application, they are the basic element of a smart inclinometer; in the other, they are the tool for monitoring passive composite anchors properly designed for slope stabilization. Measurements taken over more than one year show their feasibility in realizing a stand-alone real-time monitoring system for both landslides and interacting structures, but also reveal some difficulties and limitations inherent in their use.