Study on energy change of gas-containing coal during triaxial compression under low pressure

doi:10.16265/j.cnki.issn1003-3033.2023.S1.1942

Abstract

Abstract:

To explore the energy characteristics of coal under pressure and the law of energy change of critical destruction point, based on the stress-strain curve of gas-containing coal during conventional triaxial compression, the law of elastic strain energy and dissipation energy change with strain in the process of gas-containing coal destruction was studied. The energy explanation for the deformation of gas-containing coal under different moisture contents and different pressures was given. The results show that the effective energy ratio increases first and then decreases with the increasing moisture content under the same pressure, indicating that the increase in moisture content decreases the strength of coal samples. A multi-linear regression equation of the total energy coupling relationship between the critical destruction point during the triaxial compression deformation of gas-containing coal and pressure and moisture content was established, with a better fitting effect.

Key words: gas-containing coal, triaxial compression, energy characteristics, effective energy ratio, critical destruction point

MENG Wei, GAO Xia, ZHANG Baoyong, WU Qiang. Study on energy change of gas-containing coal during triaxial compression under low pressure[J]. China Safety Science Journal, 2023, 33(S1): 203-208.

Figures/Tables 6

Fig.1

Fig.2

Fig.3

Fig.4

Tab.1

Fig.5

References 15

[1]	吴强, 李成林, 江传力, 等. 瓦斯水合物生成控制因素探讨[J]. 煤炭学报, 2005, 20(3): 283-287.
	WU Qiang, LI Chenglin, JIANG Chuanli, et al. Discussion on the control factors of forming gas hydrate[J]. Journal of China Coal Society, 2005, 20(3): 283-287.
[2]	俞启香. 矿井瓦斯防治[M]. 徐州: 中国矿业大学出版社, 1992: 66-79..
[3]	ZHANG Zhaopeng, XIE Heping, ZHANG Ru, et al. Deformation damage and energy evolution characteristics of coal at different depths[J]. Rock Mechanics and Rock Engineering, 2019, 52(5): 1 491-1 503. doi: 10.1007/s00603-018-1555-5
[4]	李波波, 张尧, 任崇鸿, 等. 力热耦合作用下煤岩损伤的能量特征[J]. 中国安全科学学报, 2019, 29(12): 91-96. doi: 10.16265/j.cnki.issn1003-3033.2019.12.015
	LI Bobo, ZHANG Yao, REN Chonghong, et al. Energy characteristics of coal or rock damage under thermo-mechanical coupling effect[J]. China Safety Science Journal, 2019, 29(12): 91-96. doi: 10.16265/j.cnki.issn1003-3033.2019.12.015
[5]	张志镇, 高峰. 受载岩石能量演化的围压效应研究[J]. 岩石力学与工程学报, 2015, 34(1): 1-11.
	ZHANG Zhizhen, GAO Feng. Confining pressure effect on rock energy[J]. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(1): 1-11.
[6]	孟庆彬, 王从凯, 黄炳香, 等. 三轴循环加卸载条件下岩石能量演化及分配规律[J]. 岩石力学与工程学报, 2020, 39(10): 2 047-2 059.
	MENG Qingbin, WANG Congkai, HUANG Bingxiang, et al. Rock energy evolution and distribution law under triaxial cyclic loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2020, 39(10): 2 047-2 059.
[7]	臧泽升, 李忠辉, 钮月, 等. 不同瓦斯压力下煤体力学特性试验研究[J]. 中国安全科学学报, 2021, 31(3): 90-95. doi: 10.16265/j.cnki.issn1003-3033.2021.03.013
	ZANG Zesheng, LI Zhonghui, NIU Yue, et al. Experimental study on mechanical properties of coal under different gas pressure[J]. China Safety Science Journal, 2021, 31(3): 90-95. doi: 10.16265/j.cnki.issn1003-3033.2021.03.013
[8]	XUE Yi, GAO Feng, TENG Teng, et al. Effect of gas pressure on rock burst proneness indexes and energy dissipation of coal samples[J]. Geotechnical and Geological Engineering, 2016, 34(6): 1 737-1 748. doi: 10.1007/s10706-016-9985-x
[9]	JIANG Changbao, LI Zhengke, WANG Wensong, et al. Experimental investigation of the mechanical characteristics and energy dissipation of gas-containing coal under incremental tiered cyclic loading[J]. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 2021, 7(3): 1-15. doi: 10.1007/s40948-020-00190-w
[10]	杨永杰, 马德鹏. 煤样三轴卸荷破坏的能量演化特征试验分析[J]. 采矿与安全工程学报, 2018, 35(6): 1 208-1 216.
	YANG Yongjie, MA Depeng. Experimental research on energy evolution properties of coal sample failure under triaxial unloading testing[J]. Journal of Mining & Safety Engineering, 2018, 35(6): 1 208-1 216.
[11]	高霞, 刘文新, 高橙, 等. 含瓦斯水合物煤体强度特性三轴试验研究[J]. 煤炭学报, 2015, 40(12): 2 829-2 835.
	GAO Xia, LIU Wenxin, GAO Cheng, et al. Triaxial shear strength of methane hydrate-bearing coal[J]. Journal of China Coal Society, 2015, 40(12): 2 829-2 835.
[12]	陈鲜展, 袁亮, 薛生, 等. 瓦斯含量法在煤与瓦斯突出能量分析中的应用[J]. 中国安全科学学报, 2017, 27(10): 93-98. doi: 10.16265/j.cnki.issn1003-3033.2017.10.016
	CHEN Xianzhan, YUAN Liang, XUE Sheng, et al. Energy analysis of coal and gas outburst process based on gas content method[J]. China Safety Science Journal, 2017, 27(10): 93-98. doi: 10.16265/j.cnki.issn1003-3033.2017.10.016
[13]	黄达, 黄润秋, 张永兴. 粗晶大理岩单轴压缩特性的静态加载速率效应及能量机制试验研究[J]. 岩石力学与工程学报, 2012, 31(2): 33-43.
	HUANG Da, HUANG Runqiu, ZHANG Yongxing. Experimental Investigations on static loading rate effects on mechanical properties and energy mechanism of coarse crystal grain marble under uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(2): 33-43.
[14]	苏晓波, 纪洪广, 裴峰, 等. 单轴压缩荷载下含黏结面花岗岩能量演化研究[J]. 哈尔滨工业大学学报, 2018, 50(8): 161-167.
	SU Xiaobo, JI Hongguang, PEI Feng, et al. Study on energy evolution law of defective granite specimen under uniaxial compressive loading and unloading[J]. Journal of Harbin Institute of Technology, 2018, 50(8): 161-167.
[15]	JIA Zheqiang, LI Cunbao, ZHANG Ru, et al. Energy evolution of coal at different depths under unloading conditions[J]. Rock Mechanics and Rock Engineering, 2019, 52: 4 637-4 349. doi: 10.1007/s00603-019-01856-y

σ₃/ MPa	ω/%	U/ (MJ·m^-3)	U^e/ (MJ·m^-3)	U^d/ (MJ·m^-3)	(U^e/U)/ %
1	3.48	0.082	0.045	0.037	54.87
1	6.95	0.100	0.059	0.041	59.00
1	11.14	0.102	0.055	0.047	53.92
2	3.48	0.129	0.073	0.056	56.59
2	6.95	0.152	0.090	0.062	59.21
2	11.14	0.249	0.148	0.101	58.43
3	3.48	0.270	0.143	0.127	52.96
3	6.95	0.278	0.169	0.109	60.79
3	11.14	0.313	0.187	0.126	59.74