Strata Monitoring Instruments are devices used in underground mines to measure and monitor the movement, stress, and deformation of rock strata (roof, floor, and sidewalls). These instruments help in detecting early signs of roof instability and preventing roof fall accidents.
Tell-Tale
A simple visual indicator used to monitor roof movement.
Installed in boreholes in the mine roof.
Consists of colored indicators showing roof separation or displacement.
Roof Extensometer
Measures roof displacement and layer separation in rock strata.
Can measure movement at different depths in the roof.
Convergence Meter
Measures reduction in distance between roof and floor or between sidewalls of a roadway.
Load Cell / Stress Meter
Installed on roof bolts or supports to measure the load or stress acting on them.
Strain Gauge
Measures strain (deformation) in rock or support structures.
Borehole Pressure Cell
Used to measure stress changes within the rock mass.
Importance of Strata Monitoring
Prevents roof fall accidents
Helps maintain mine safety and stability
Assists in designing proper support systems
Monitors behavior of rock strata during mining
Applicability in Mines
Strata monitoring instruments are used in:
Underground coal mines
Mines using Continuous Miner or Longwall mining
Room and Pillar mining operations
Areas with weak roof strata or high stress conditions