Experimental investigation into interface effect and progressive instability of coal-rock combined specimen

被引：0
|
作者：
Yang K. [1 ,2 ,3 ,4 ]
Liu W. [1 ,3 ,4 ]
Dou L. [1 ,3 ,4 ]
Chi X. [1 ,3 ,4 ]
Wei Z. [1 ,3 ,4 ]
Fu Q. [1 ,3 ,4 ]
机构：
[1] State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan
[2] Institute of Energy, Hefei Comprehensive National Science Center, Hefei
[3] National & Local Joint Engineering Research Center of Precision Coal Mining, Anhui University of Science and Technology, Huainan
[4] Key Laboratory of Mining Coal Safety and Efficiently Constructed by Anhui Province and Ministry of Education, Anhui University of Science and Technology, Huainan
来源：
Meitan Xuebao/Journal of the China Coal Society | 2020年 / 45卷 / 05期
关键词：
Crack propagation; Discontinuous damage; Dynamic disaster prevention; Energy conversion law; Failure mechanism; Meso-damage characteristic;
D O I：
10.13225/j.cnki.jccs.DY20.0294
中图分类号：
学科分类号：
摘要：
The characteristics of the coal-rock mass combination determine the deformation and instability of the overall structure formed by the coal-rock combination.In order to analyze the influence of the coal-rock height ratio on the mechanical characteristics, energy conversion laws, and the instability failure characteristics of the combination under load, "Rock-Coal-Rock"(RCR) test specimens with three different proportions of height ratio were made.Subsequently, a uniaxial compression test and a PFC2D numerical simulation of combined test pieces were carried out.Based on the analysis of acoustic emission and macro-destructive characteristics, the meso-damage characteristics, macro-mechanical characteristics, and acoustic emission energy evolution laws of the assembly before and after transient instability were obtained.The research shows that with the increase of the height ratio of coal and rock, the uniaxial compressive strength, elastic modulus and dynamic intensity at the failure of the combination decrease.The damage of the specimens is an asymptotic discontinuity.The damage first occurs and develops in the coal body in the specimens.Then when the coal crack develops to the interface of coal and rock, it is blocked.Finally, due to the influence of the Poisson effect of the composite body and the increase of the elastic energy storage of the composite body, the cracks propagate from the coal body to the rock, and the composite body undergoes an overall failure.Due to the difference in the structure and elastic energy storage of the RCR specimens, the crack propagation ability, speed and angle are different.Furthermore, the combination has different failure shapes, but the failure patterns are similar.Among them, the coal body is dominated by shear failure, and the top and bottom rocks are dominated by split failure.The acoustic emission signal of RCR specimens has obvious phase characteristics when it is loaded.When the overall instability occurs, the acoustic emission energy rises rapidly and reaches a maximum.According to the regular characteristics of acoustic emission events, the instantaneous damage of RCR specimens can be monitored and warned, which provides a reference for the mechanism and prediction of rock burst. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.
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页码：1691 / 1700
页数：9
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