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Open AccessArticle

Correlational Analytical Characterization of Energy Dissipation-Liberation and Acoustic Emission during Coal and Rock Fracture Inducing by Underground Coal Excavation

School of Energy and Mining Engineering, Xi’an University of Science and Technology, Xi’an 710054, China
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Energies 2019, 12(12), 2382; https://doi.org/10.3390/en12122382
Received: 4 April 2019 / Revised: 21 May 2019 / Accepted: 12 June 2019 / Published: 20 June 2019
This paper uses an acoustic emission (AE) test to examine the energy dissipation and liberation of coal and rock fracture due to underground coal excavation. Many dynamic failure events are frequently observed due to underground coal excavation. To establish the quantitative relationship between the dissipated energy and AE energy parameters, the coal and rock fracturing characteristics were clearly observed. A testing method to analyze the stage traits and energy release mechanism from damage to fracture of the unloading coal and rock under uniaxial compressive loading is presented. The research results showed that the relevant mechanical parameter discreteness was too large because the internal structures of the coal and rock were divided into multiple structural units (MSU) by a few main cracks. The AE test was categorized into four stages based on both the axial stress and AE event parameters: initial loading stage, elastic stage, micro-fracturing stage, and post-peak fracturing stage. The coal and rock samples exhibited minimum (maximum) U values of 60.44 J (106.41 J) and 321.19 J (820.87 J), respectively. A theoretical model of the dissipation energy during sample fracturing based on the AE event energy parameters was offered. The U decreased following an increase in ΣEAE-IIEAE. View Full-Text
Keywords: Coal excavation; coal and rock fracture; multiple structural units (MSU); energy dissipation; AE energy Coal excavation; coal and rock fracture; multiple structural units (MSU); energy dissipation; AE energy
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Shan, P.; Lai, X.; Liu, X. Correlational Analytical Characterization of Energy Dissipation-Liberation and Acoustic Emission during Coal and Rock Fracture Inducing by Underground Coal Excavation. Energies 2019, 12, 2382.

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