Long-Term Monitoring of a Tunnel in a Landslide Prone Area by Distributed Optical Fiber Sensors

The work deals with the exploitation of a distributed fiber-optic strain sensor for long-term monitoring of a railway tunnel affected by an active landslide located in southern Italy. The optical fibers have been applied to detect the strain distribution along the two walls of the tunnel. The experimental results, relative to a three years' span, show the sensor's ability to identify the location along the tunnel walls of potentially dangerous strained regions and follow their temporal evolution, as well.