Influence of amygdale on crack evolution and failure behavior of basalt

doi:10.1016/j.engfracmech.2019.106843

	Influence of amygdale on crack evolution and failure behavior of basalt
	Zhang, Chuanqing 2,3; Liu, Zhenjiang 2,3; Pan, Yibin 1; Gao, Yang 2,3; Zhou, Hui 2,3; Cui, Guojian 2,3
刊名	ENGINEERING FRACTURE MECHANICS
	2020-03-01
卷号	226 页码:22
关键词	Baihetan hydropower station Amygdaloidal basalt Heterogeneity Deformation and failure characteristics Crack propagation evolution FDEM
ISSN号	0013-7944
DOI	10.1016/j.engfracmech.2019.106843
英文摘要	Amygdaloidal basalt is one of the two major types of surrounding rocks that are widely exposed in the super large-scale underground powerhouse caverns of Baihetan Hydropower Station, China. Excavation of the caverns induced a series of mechanical responses, including cracking and fracture relaxation. This study comprehensively explored the deformation and failure characteristics and the fracture evolution process of the amygdaloidal basalt using conventional MTS triaxial laboratory testing equipment and continuous-discontinuous modeling (FDEM) with the aim of clarifying its failure mechanism. The research results indicate that: (1) amygdales significantly changed the deformation and failure characteristics of basalt. Whereas the post-peak mechanical behavior of cryptocrystalline basalt was brittle, that of amygdaloidal basalt was brittle under low confining stresses and ductile under high confining stresses. Meanwhile, whereas the failure mode of cryptocrystalline basalt was fragmentation failure, that of amygdaloidal basalt was splitting failure at low confining stresses and shear failure at high confining stresses. (2) An FDEM model considering the heterogeneity of the rock mesostructure was established based on the statistical laws of the amygdales in real samples, and this confirmed the stress-strain curve characteristics, failure modes, and characteristic strengths measured in laboratory tests. (3) A complicated inhomogeneous stress field formed readily around amygdales and had a significant effect on the fracture path. (4) With an increase in confining stresses, the degree of tensile stress concentration at the upper and lower tips of amygdales decreased and the lateral displacement became restricted. Consequently, the total number of micro-cracks and the ratio of tensile cracks to shear cracks decreased, the crack initiation mode changed from tensional cracking to shear cracking at the tips of the amygdale, and the distribution of crack orientations transitioned from an approximately vertical direction to preferential concentration along fracture planes. The research results form a solid foundation for the accurate understanding of the mechanical response and fracture mechanism of the rock surrounding underground powerhouse caverns at Baihetan hydropower station, and also provide a reference for the prediction of the mechanical properties of rock with flaws and the stability control of engineering rockmasses.
资助项目	Key Projects of the Yalong River Joint Fund of the National Natural Science Foundation of China[U1865203] ; National Natural Science Foundation of China[51279201] ; Youth Innovation Promotion Association CAS
WOS研究方向	Mechanics
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000509727900017
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/23438]
专题	中科院武汉岩土力学所
通讯作者	Liu, Zhenjiang
作者单位	1.PowerChina Huadong Engn Corp Ltd, Hangzhou 310014, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Chuanqing,Liu, Zhenjiang,Pan, Yibin,et al. Influence of amygdale on crack evolution and failure behavior of basalt[J]. ENGINEERING FRACTURE MECHANICS,2020,226:22.
APA	Zhang, Chuanqing,Liu, Zhenjiang,Pan, Yibin,Gao, Yang,Zhou, Hui,&Cui, Guojian.(2020).Influence of amygdale on crack evolution and failure behavior of basalt.ENGINEERING FRACTURE MECHANICS,226,22.
MLA	Zhang, Chuanqing,et al."Influence of amygdale on crack evolution and failure behavior of basalt".ENGINEERING FRACTURE MECHANICS 226(2020):22.