Micro- and macrocracking behaviors in granite and molded gypsum containing a single flaw

doi:10.1016/j.conbuildmat.2021.123452

	Micro- and macrocracking behaviors in granite and molded gypsum containing a single flaw
	Zhang, Guokai 1,2; Wang, Mingyang 1,3; Li, Xiaofeng 2; Yue, Songlin 3; Wen, Zhu 1; Han, Songtong 1
刊名	CONSTRUCTION AND BUILDING MATERIALS
	2021-07-19
卷号	292 期号:-页码:15
关键词	Rock material Micro- and macrocrack initiation P-wave attenuation Acoustic emission Crack coalescence
ISSN号	0950-0618
DOI	10.1016/j.conbuildmat.2021.123452
英文摘要	The effect of preexisting defects on fracture behaviors is significant for the stability analysis of rock engineering. To study the effect of preexisting flaws on the micro- and macrocracking behaviors of rocks, photographic monitoring together with strain field analysis, passive acoustic emission (AE) and active ultrasonic testing were carried out on gypsum and granite samples containing a single flaw. Based on coupled analysis of the acousto-optic-mechanical characteristics, it is suggested to identify micro- and macrocrack initiation by AE monitoring rather than stress-strain behaviors, photographic observation and P-wave measurement. The micro- and macrocrack initiation stresses generally increase with the flaw angle. The microcrack initiation stress ranging from 0.22 sigma(c) to 0.62 sigma(c) (peak strength) coincides with the onset of AE events, and the macrocrack initiation stress ranging from 0.60 sigma(c) to 0.85 sigma(c) coincides well with a dramatic increase in AE energy for flawed granite. The crack types are classified into nine different categories. Macrocrack coalescence is observed before reaching sigma(c), and violent rock failure occurs seconds after sigma(c) is achieved for flawed granites, which differs from that process for gypsum samples. The cracking process of flawed granites experiences three typical stages and is highly dependent on the flaw angle. A stress drop accompanied by a significant increase in the AE energy rate appears several times. With an increasing flaw angle, the count of stress drop and the cumulative AE energy decrease, while the maximum value of the AE energy rate and the average hit energy increase gradually. The energy and stress release reduces the violent failure degree of rock. The AE energy correlated with the cracking magnitude changes more violently than the AE event before peak failure. P-wave attenuation increases sharply after macrocrack initiation. A sharp reduction in velocity is always accompanied by a significant increase in the AE rate. Compared with the global cracking damage of rock characterized by AE characteristics, the fracture identified by P-wave velocity is localized. (C) 2021 Elsevier Ltd. All rights reserved.
资助项目	National Natural Science Foundation of China[51809137] ; Natural Science Foundation of Jiangsu Province[BK20180480] ; China Postdoctoral Science Foundation[2020M681610] ; Open Research Fund ofState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences[Z017015] ; Open Research Fund ofState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences[Z019013]
WOS研究方向	Construction & Building Technology ; Engineering ; Materials Science
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000660565200011
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27502]
专题	中科院武汉岩土力学所
作者单位	1.Nanjing Univ Sci & Technol, Sch Mech Engn, Nanjing 210094, Peoples R China 2.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China 3.Army Engn Univ PLA, State Key Lab Disaster Prevent & Mitigat Explos &, Nanjing 210014, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Guokai,Wang, Mingyang,Li, Xiaofeng,et al. Micro- and macrocracking behaviors in granite and molded gypsum containing a single flaw[J]. CONSTRUCTION AND BUILDING MATERIALS,2021,292(-):15.
APA	Zhang, Guokai,Wang, Mingyang,Li, Xiaofeng,Yue, Songlin,Wen, Zhu,&Han, Songtong.(2021).Micro- and macrocracking behaviors in granite and molded gypsum containing a single flaw.CONSTRUCTION AND BUILDING MATERIALS,292(-),15.
MLA	Zhang, Guokai,et al."Micro- and macrocracking behaviors in granite and molded gypsum containing a single flaw".CONSTRUCTION AND BUILDING MATERIALS 292.-(2021):15.