Asperity degradation characteristics of soft rock-like fractures under shearing based on acoustic emission monitoring

doi:10.1016/j.enggeo.2019.105392

	Asperity degradation characteristics of soft rock-like fractures under shearing based on acoustic emission monitoring
	Meng, Fanzhen 3,4; Wong, Louis Ngai Yuen 3; Zhou, Hui 2; Wang, Zaiquan 1,4; Zhang, Liming 1,4
刊名	ENGINEERING GEOLOGY
	2020-03-05
卷号	266 页码:14
关键词	Rock fracture Acoustic emission Asperity degradation Damage model AE b-value
ISSN号	0013-7952
DOI	10.1016/j.enggeo.2019.105392
英文摘要	Shear failure of rock masses along pre-existing discontinuities is one of the predominant failure modes of rock slopes and underground tunnels. The monitoring and prediction of the impending shear failure is of great significance to ensure the stability of the rock structures and the safety of the workers. In this study, direct shear tests under normal stress ranging from 0.5 to 10 MPa are conducted on rock fractures (analogous to soft rock discontinuities), which are obtained by artificial splitting, during which the AE parameters are monitored. Test results show that the AE parameters (hit, energy and events) increase with the shear stress, and peak at or near the peak shear strength, after which the AEs gradually decay with the decrease of shear stress. The number of AE events first increases and then decreases with increasing normal stress, which may be associated with the ductile deformation of the porous structure of cement mortar under higher normal stress. The degradation of asperities on the fracture surface can be inferred from the accumulative AE hits and events, which are characterized by "S" shapes and can be divided into slow growth, fast growth and slow growth stages. Conceptual and mathematical asperity damage models are proposed respectively based on the temporal characteristics of AE events and the curve fitting, which can be used to predict the asperity damage for a given shear stress curve. The AE b-value fluctuates and remains high in the shear process. There is no strong correlation between the shear stress and the b-value, which indicates that the b-value may not be an effective index to predict the quasi-static shear failure of jointed rock masses possessing similar properties like cement mortar. Results of this study will not only contribute to a better understanding of the asperity degradation characteristics but also provide valuable knowledge for AE monitoring applications in jointed rock masses.
资助项目	National Natural Science Foundation of China[51879135] ; National Natural Science Foundation of China[51609121] ; National Natural Science Foundation of China[41472270] ; National Natural Science Foundation of China[51679093] ; National Natural Science Foundation of China[41372298] ; Natural Science Foundation of Shandong Province[ZR2016EEQ22] ; Hong Kong Scholars Program[XJ2017043] ; Research Grants Council of Hong Kong[17303917] ; Hung Hing Ying Physical Sciences Research Fund 2017-18
WOS研究方向	Engineering ; Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000520942400005
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/23755]
专题	中科院武汉岩土力学所
通讯作者	Wong, Louis Ngai Yuen
作者单位	1.Cooperat Innovat Ctr Engn Construct & Safety Shan, Qingdao, Shandong, Peoples R China 2.Chinese Acad Sci, State Key Lab Geomech & Geotech Engn, Inst Rock & Soil Mech, Wuhan 430071, Hubei, Peoples R China 3.Univ Hong Kong, Dept Earth Sci, Pokfulam, Hong Kong, Peoples R China 4.Qingdao Univ Technol, Coll Sci, Qingdao 266033, Shandong, Peoples R China
推荐引用方式 GB/T 7714	Meng, Fanzhen,Wong, Louis Ngai Yuen,Zhou, Hui,et al. Asperity degradation characteristics of soft rock-like fractures under shearing based on acoustic emission monitoring[J]. ENGINEERING GEOLOGY,2020,266:14.
APA	Meng, Fanzhen,Wong, Louis Ngai Yuen,Zhou, Hui,Wang, Zaiquan,&Zhang, Liming.(2020).Asperity degradation characteristics of soft rock-like fractures under shearing based on acoustic emission monitoring.ENGINEERING GEOLOGY,266,14.
MLA	Meng, Fanzhen,et al."Asperity degradation characteristics of soft rock-like fractures under shearing based on acoustic emission monitoring".ENGINEERING GEOLOGY 266(2020):14.