Optical Fiber Sensing in Coal Mine Structural Monitoring

Optical fiber sensing has emerged as a transformative approach for monitoring the structural integrity of underground coal mining environments. By exploiting the intrinsic sensitivity of optical fibers to strain, temperature and acoustic perturbations, both distributed and point‐based sensor networks can deliver real‐time, continuous profiles of deformation and stress evolution across hundreds of metres. Key techniques such as Fiber Bragg Gratings, Brillouin Optical Time Domain Analysis and Reflectometry enable high spatial resolution and long‐distance coverage without the need for electrical power sources in the measurement zone. These systems have been deployed to track overburden subsidence, roof strata movement, key‐stratum deformation and goaf pressure, thereby providing early warning of roof collapse, water inrush or gas outburst. The integration of multi‐parameter sensing, advanced data processing and threshold‐based alarms supports intelligent mining operations and enhances safety management on a global scale.

Research from Nature Portfolio

Recent studies have demonstrated a multi‐method joint monitoring framework to characterise strata behaviour in shallow seam mining under complex landforms. In this work, distributed optical fiber sensors based on Brillouin Optical Time Domain Analysis were combined with digital image correlation and in situ pressure transducers to capture the strain, deformation and stress fields of overburden in alpine gully conditions. The hybrid sensor array revealed periodic roof weighting events, spatial zoning of abutment pressure, and the dynamic evolution of tension cracks and block rotations. These findings have informed refined support designs and mining sequences to mitigate roof instability in topographically varied coalfields.

Optical Fiber Sensing in Coal Mine Structural Monitoring publication trend

The graph below shows the total number of articles in optical fiber sensing in coal mine structural monitoring across all publications each year (not limited to Nature Index journals).

Technical terms

Distributed Fiber-Optic Sensing (DFOS): A method that employs optical fibers as continuous sensors for spatially resolved measurements of strain, temperature or acoustic signals.

Brillouin Optical Time Domain Analysis (BOTDA): A distributed sensing technique based on stimulated Brillouin scattering to measure strain and temperature along an optical fiber.

Brillouin Optical Time Domain Reflectometry (BOTDR): A single‐ended distributed sensing method relying on spontaneous Brillouin scattering for strain and temperature profiling.

Fiber Bragg Grating (FBG): A point sensor inscribed within an optical fiber that reflects specific wavelengths, shifting in response to local strain or temperature changes.

Digital Image Correlation (DIC): A non‐contact optical technique for measuring surface deformation by tracking patterns on a specimen.

Goaf: The caved or unsupported region left after coal extraction, where pressure distribution monitoring is critical.

References

1. Multi-method joint monitoring study on strata behavior in shallow seam mining under bedrock gully. Scientific Reports (2023).
2. Research on transparency of coal mine geological conditions based on distributed fiber‐optic sensing technology. Deep Underground Science and Engineering (2024).
3. Research on a Space–Time Continuous Sensing System for Overburden Deformation and Failure during Coal Mining. Sensors (2023).
4. Experimental study on a new method to forecasting goaf pressure based key strata deformation detected using optic fiber sensors. Optical Fiber Technology (2021).