Laboratory Testing of an Optical Fiber-Based Monitoring System Developed for Earthquake-Induced Landslides

The utilization of fiber optics has gained popularity for landslide monitoring and other geoengineering applications due to their advantages that ensure applicability in a wide range of environments and the ability to perform continuous monitoring. This study aims to establish a monitoring system by employing fiber optic cables to simultaneously monitor deformations triggered by earthquakes on the landslide failure surface. To that end, a landslide container holding an artificial slope was placed on a shaking table in the laboratory to monitor the deformations of the slope. The deformation was measured by fiber optic cables in terms of strain through a system developed with a Brillouin Optical Time Domain Analyzer (BOTDA). Moreover, LVDTs located at the same level as fiber optic cables were employed for verification. Also, surface deformation was detected by high-resolution cameras. Besides, accelerometers were positioned within the slope model to consider the dynamic site response. By employing different fiber optic cables, a series of experiments were conducted on the shaking table at different velocities along with varying amplitudes, and feasible cables for a real-time field application were selected. The sensitivity analysis results of the laboratory studies serve as a base for the field application planned in Yalova province of Türkiye, which possesses high earthquake hazard potential. Displacement verification in the field has been performed with inclinometers and accelerometers deployed in the landslide, and a UAV. The proposed system is expected to be used as a monitoring and early warning system to evaluate the landslide movements induced by earthquakes.