Development and application of FBG sensors for landslide monitoring

Accurate measurement of surface and subsurface information in a landslide has become a great concern in recent years. Fiber Bragg grating (FBG), as a popular quasi-distributed fiber optic sensing technology, has been successfully applied to geotechnical and geohazard monitoring in the past several decades. This paper briefly introduces the sensing principles of FBG and ultra-weak FBG (UWFBG) technologies for landslide monitoring. A series of FBG-based sensors and their developed methods for measuring critical physical and mechanical parameters are subsequently summarized regarding strain, temperature, displacement, pressure, and moisture content. Finally, two case studies for FBG-based landslide monitoring are provided for validation. With the increasingly improved spatial resolution, FBG- and UWFBG-based sensors are expected to take geotechnical monitoring to a higher level.