Original scientific paper

https://doi.org/10.17559/TV-20260331003499

Study on the Radon Emission Law During the Process of Coal Sample Fracture under Loading and Unloading Paths

Yun Chen ; Joint National-Local Engineering Research Center for Safe and Precise Coal Mining, Anhui University of Science and Technology, Huainan 232001, China *
Xiao Liu ; China Coal Technology and Engineering Group Shenyang Research Institute Co., Ltd., State Key Laboratory of Coal Mine Disaster Prevention and Control Fushun, Liaoning Province, 113122, China
Peng Yang ; Joint National-Local Engineering Research Center for Safe and Precise Coal Mining, Anhui University of Science and Technology, Huainan 232001, China

* Corresponding author.

Abstract

To investigate the variation pattern of radon concentration during the rupture of coal samples under different loading and unloading paths, this paper establishes a mechanical model for fractured coal samples under confining pressure, analyzes the failure criteria of coal samples, and conducts radon concentration emission experiments under uniaxial compression, triaxial compression, and confining pressure unloading stress paths. The radon emission patterns during the rupture of coal samples under different stress paths were obtained. The experimental results show that: in the uniaxial compression test, the radon concentration increases during the compaction and closure stage, slightly decreases during the elastic stage, rises rapidly during the plastic deformation stage, and tends to stabilize upon sample failure; under triaxial loading and confining pressure unloading stress paths, except when the confining pressure reaches 5 MPa, the radon concentration during the compaction and closure stage is lower than the initial concentration, the other variation patterns are consistent with those of uniaxial compression; under triaxial compression, the increase in confining pressure leads to a slow rise in radon concentration, but high confining pressure restricts crack development and affects radon emission. Affected by the confining pressure effect, the radon concentration decreases during the compaction and closure stage under high confining pressure, but rises again after the axial pressure increases; radon concentration changes significantly during unloading; the greater the confining pressure, the more significant the change degree.

Keywords

failure mode; stress path; radon concentration; emission pattern; coal failure; confining pressure unloading

Hrčak ID:

353097

URI

https://hrcak.srce.hr/353097

Publication date:

7.11.2026.

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