Abstract
Geomechanical characterization and monitoring are essential for subsurface projects, including underground mining, geo-energy production, groundwater management, and geological storages of CO2 and radioactive waste. Traditional measurement techniques often face challenges such as limited spatial coverage and high operational costs. Fiber optic sensing (FOS) offers a promising alternative due to its scalability, durability, and high spatial resolution, making it particularly suitable for harsh environments and large-scale applications. This paper provides a comprehensive and critical review of the use of FOS in geomechanics, covering the principles of quasi- and fully distributed sensing and focusing on strain measurement in both laboratory and field settings. We discuss various techniques for fiber cable installation and explore the integration of FOS with other geomechanical monitoring techniques. Based on the challenges identified in the reviewed studies, we conclude that there is a need for improved fiber coupling and measurement corrections, efficient fiber cable installation, robust data handling and interpretation, and standardization across different geomechanical applications.