Distributed Optical Fiber Sensor Applications in Geotechnical Monitoring

Abstract

We report the experimental application of distributed optical fiber sensors, based on stimulated Brillouin scattering (SBS), to the monitoring of a small-scale granular slope reconstituted in an instrumented flume and subjected to artificial rainfall until failure, and to the monitoring of a volcanic rock slope. The experiments demonstrate the sensors’ ability to reveal the sudden increase in soil strain that foreruns the failure in a debris flow phenomenon, as well as to monitor the fractures in the tuff rocks. This study offers an important perspective on the use of distributed optical fiber sensors in the setting up of early warning systems for landslides in both rock and unconsolidated materials.

Innovative Photonic Sensors for Safety and Security, Part III: Environment, Agriculture and Soil Monitoring

“…For the flume experiment, a high spatial resolution (5 cm) distributed optical fiber sensor based on the Brillouin Optical Frequency-Domain Analysis (BOFDA) was chosen. The purpose of this experiment was investigating the failure of a small-scale volcanic slope subjected to artificial rainfall [ 65 ]. For our experiments, soil from the Cervinara site was employed (northeast of Naples, Italy), an area affected by a devastating debris avalanche in 1999.…”

“… ( a ) Fiber installation during the reconstitution of the slope; ( b ) Strain trends measured by the optical fiber sensor (from Ref. [ 65 ]). …”

Slope Micrometeorological Analysis and Prediction Based on an ARIMA Model and Data-Fitting System

“…Through the flexible deployment of wireless monitoring sensor equipment, it is possible to monitor challenging environments such as high-tree crowns and high slopes for better data monitoring. Therefore, the wireless sensor is considered to be one of the most effective instruments for slope micrometeorological monitoring [ 25 , 26 , 27 ].…”

Influence of Fines Content on the Stability of Volcanic Embankments under Rainfall and Earthquake

“…Along with the development of technology, measuring devices for physical modeling experiments in the geotechnical field are constantly being researched and improved. Minardo et al, (2021) [13] used the distributed optical fiber sensors in flume tests with volcanic sand subjected to rainfall as well as in the monitoring of a coastal cliff to propose its application in the early warning system. Zhang et al, (2018) [14] presented the potential for measurement of deep deformation in landslide model tests of a flexible inclinometer probe, a design that includes gravity acceleration sensors.…”