Examining the optimum panel pillar dimension in longwall mining considering stress distribution

Area of Science:

• Mining Engineering
• Geotechnical Engineering
• Rock Mechanics

Background:

• Longwall mining is a prevalent global method for underground coal extraction.
• Understanding stress distribution around longwall panels is crucial for operational safety and efficiency.
• The impact of these stresses on mine infrastructure, including gates and haulage roads, requires detailed analysis.

Purpose of the Study:

• To investigate the effect of safety pillars at panel ends on the main haulage road.
• To determine the optimal pillar distance that minimizes stress-induced damage to critical underground roadways.
• To assess the influence of pillar distance on coal recovery efficiency.

Main Methods:

• Development and analysis of six distinct numerical models.
• Simulation of varying safety pillar distances.
• Examination of stress distribution within the main haulage road, tailgate, and main gate across different models.

Main Results:

• Numerical models demonstrated that specific pillar distances do not cause damage to the main haulage road, tailgate, and main gate.
• A pillar distance of 10 meters was identified as yielding maximum coal recovery efficiency.
• Simulated stresses at the 10m pillar distance were found to be non-damaging to the analyzed roadways.

Conclusions:

• The study confirms that judicious selection of safety pillar dimensions can mitigate damage risks in underground coal mines.
• An optimal pillar distance of 10 meters balances high coal recovery with the structural integrity of essential mine infrastructure.
• Numerical modeling provides a reliable method for assessing stress impacts and optimizing mine design parameters.