Rapid decompression and desorption induced energetic failure in coal

• Published in: Journal of Rock Mechanics and Geotechnical Engineering Vol. 7; no. 3; pp. 345 - 350
• Main Authors: Wang, Shugang, Elsworth, Derek, Liu, Jishan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2015; a Department of Energy and Mineral Engineering, EMS Energy Institute and G3 Center, Pennsylvania State University, University Park, PA, USA b School of Mechanical and Chemical Engineering, University of Western Australia, Crawley, WA, Australia; Elsevier
• Subjects: Coal; Energetic failure; Gas desorption; Gas outburst; Rapid decompression; 减压; 实验室实验; 煤样; 能量; 脱附; 衰竭; 解吸作用; 诱导; Gas outburst; Gas desorption; Energetic failure; Rapid decompression; Coal
• ISSN: 1674-7755
• DOI: 10.1016/j.jrmge.2015.01.004

In this study, laboratory experiments are conducted to investigate the rapid decompression and desorption induced energetic failure in coal using a shock tube apparatus. Coal specimens are recovered from Colorado at a depth of 610 m. The coal specimens are saturated with the strong sorbing gas CO2 for a certain period and then the rupture disc is suddenly broken on top of the shock tube to generate a shock wave propagating upwards and a rarefaction wave propagating downwards through the specimen.This rapid decompression and desorption has the potential to cause energetic fragmentation in coal.Three types of behaviors in coal after rapid decompression are found, i.e. degassing without fragmentation, horizontal fragmentation, and vertical fragmentation. We speculate that the characteristics of fracture network（e.g. aperture, spacing, orientation and stiffness） and gas desorption play a role in this dynamic event as coal can be considered as a dual porosity, dual permeability, dual stiffness sorbing medium. This study has important implications in understanding energetic failure process in underground coal mines such as coal gas outbursts.