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Updated: Aug 10, 2026
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A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System
Published on: June 12, 2019
Evolution Characteristics of Coal Fractures under High-Temperature Coupling with Triaxial Stress
Lanyun Wang1, Xiyu Liu1, Yongliang Xu1
1School of Safety Science and Engineering, Changzhou University, Changzhou, Jiangsu 213164, China.
ACS Omega
|August 8, 2026
Summary
High temperatures from underground coal fires significantly alter coal fracture networks, impacting mining safety. Understanding this fracture evolution is key for effective fire prevention strategies.
Area of Science:
- Geotechnical Engineering
- Mining Engineering
- Materials Science
Background:
- Underground coal fires present significant mining safety and environmental risks.
- Fracture development in coal facilitates oxygen and heat transfer, exacerbating fires.
- The evolution of coal fractures under combined heat and stress is not well understood.
Purpose of the Study:
- To investigate the dynamic evolution of fractures in thermally treated coal under triaxial stress.
- To quantify the impact of high temperatures on coal's mechanical properties and fracture characteristics.
- To provide a theoretical basis for predicting fracture network evolution in coal fire zones.
Main Methods:
- Bituminous coal samples were treated at 200 °C and 400 °C.
- Triaxial compression tests were performed at 5 MPa confining pressure.
- Industrial CT scanning monitored fracture evolution, analyzed with VG Studio MAX software.
Main Results:
- Temperature significantly influences coal's mechanical behavior and fracture development.
- High-temperature treatment increased coal porosity (e.g., 0.07% to 0.70% for RC to C400).
- Fracture evolution occurred in three distinct stages: smooth development, slow growth, and rapid growth, confirmed by 3D fractal dimension.
Conclusions:
- Thermal treatment alters coal's mechanical properties, reducing elastic modulus and affecting peak stress.
- Fracture evolution in fire-affected coal follows a predictable, staged pattern.
- Findings offer practical guidance for coal fire prevention and management.
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