Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine

The force and deformation characteristics of the rock layer on the top and bottom of the coal seam change significantly when the dip angle changes. The mechanical properties and damage characteristics of differently inclined coal–rock assemblages were investigated, and the results were combined with...

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Main Authors: Yuping Fu, Yongliang He, Chuantian Li
Format: Article
Language:English
Published: Hindawi Limited 2023-01-01
Series:Advances in Civil Engineering
Online Access:http://dx.doi.org/10.1155/2023/9969802
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author Yuping Fu
Yongliang He
Chuantian Li
author_facet Yuping Fu
Yongliang He
Chuantian Li
author_sort Yuping Fu
collection DOAJ
description The force and deformation characteristics of the rock layer on the top and bottom of the coal seam change significantly when the dip angle changes. The mechanical properties and damage characteristics of differently inclined coal–rock assemblages were investigated, and the results were combined with acoustic emission information, including acoustic emission ringdown counts, to quantify the damage of inclined coal–rocks under compression. The experimental results showed that the stress‒strain curves of the inclined coal–rock assemblages had four main stages, with approximately similar curves in the early stage and deformation in the later stage. The damage gradually changed from shear damage to interfacial slip damage, and the damage area gradually transitioned to the structural surface from coal body components. The cumulative acoustic emission energy tended to decrease with increasing inclination angle, and the peak acoustic emission energy gradually decreased. When the inclination angle was less than 30°, the cumulative energy of acoustic emissions increased slowly, then decreased, and it finally decreased significantly between 30° and 45°; from 0° → 15° → 30° → 45°, the energy change rates were +3.0%, −25.1%, and −78.2%, respectively. For coal–rock assemblages with different interfacial angles, the sliding damage instability caused by the coal–rock interface increased with increasing interfacial angle within the assemblage. The results of this study provide a deeper understanding of the mechanical properties of coal–rock assemblages with different inclinations and the characteristics of fissure extension. The fractal dimension based on particle number decreased with increasing loading rate, and the larger the loading rate was, the smaller the fractal dimension. In addition, the current findings provide a reliable foundation for further understanding the mechanisms of disasters caused by coal–rock disturbances, such as excavation of inclined roadways and extraction of gas, as well as supporting the development of methods for monitoring, early warning, and prevention and control of these types of disasters.
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spelling doaj.art-718d20cdb9474cb6acd7c2d1539b3fea2024-01-03T00:00:02ZengHindawi LimitedAdvances in Civil Engineering1687-80942023-01-01202310.1155/2023/9969802Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal MineYuping Fu0Yongliang He1Chuantian Li2School of Engineering for Safety and Emergency ManagementSchool of Engineering for Safety and Emergency ManagementSchool of Engineering for Safety and Emergency ManagementThe force and deformation characteristics of the rock layer on the top and bottom of the coal seam change significantly when the dip angle changes. The mechanical properties and damage characteristics of differently inclined coal–rock assemblages were investigated, and the results were combined with acoustic emission information, including acoustic emission ringdown counts, to quantify the damage of inclined coal–rocks under compression. The experimental results showed that the stress‒strain curves of the inclined coal–rock assemblages had four main stages, with approximately similar curves in the early stage and deformation in the later stage. The damage gradually changed from shear damage to interfacial slip damage, and the damage area gradually transitioned to the structural surface from coal body components. The cumulative acoustic emission energy tended to decrease with increasing inclination angle, and the peak acoustic emission energy gradually decreased. When the inclination angle was less than 30°, the cumulative energy of acoustic emissions increased slowly, then decreased, and it finally decreased significantly between 30° and 45°; from 0° → 15° → 30° → 45°, the energy change rates were +3.0%, −25.1%, and −78.2%, respectively. For coal–rock assemblages with different interfacial angles, the sliding damage instability caused by the coal–rock interface increased with increasing interfacial angle within the assemblage. The results of this study provide a deeper understanding of the mechanical properties of coal–rock assemblages with different inclinations and the characteristics of fissure extension. The fractal dimension based on particle number decreased with increasing loading rate, and the larger the loading rate was, the smaller the fractal dimension. In addition, the current findings provide a reliable foundation for further understanding the mechanisms of disasters caused by coal–rock disturbances, such as excavation of inclined roadways and extraction of gas, as well as supporting the development of methods for monitoring, early warning, and prevention and control of these types of disasters.http://dx.doi.org/10.1155/2023/9969802
spellingShingle Yuping Fu
Yongliang He
Chuantian Li
Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
Advances in Civil Engineering
title Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
title_full Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
title_fullStr Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
title_full_unstemmed Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
title_short Failure and Acoustic Emissions of Coal–Rock Combinations with Different Dip Angles in the Shaqu No. 1 Coal Mine
title_sort failure and acoustic emissions of coal rock combinations with different dip angles in the shaqu no 1 coal mine
url http://dx.doi.org/10.1155/2023/9969802
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AT chuantianli failureandacousticemissionsofcoalrockcombinationswithdifferentdipanglesintheshaquno1coalmine