Fault nucleation of tight sandstone by investigation of mechanical, acoustic, and hydraulic responses

doi:10.1016/j.enggeo.2021.106254

	Fault nucleation of tight sandstone by investigation of mechanical, acoustic, and hydraulic responses
	Li, Xiaying 1,2; Lei, Xinglin 3; Li, Qi 1,2
刊名	ENGINEERING GEOLOGY
	2021-10-01
卷号	292 页码:9
关键词	Water weakening Strain softening Acoustic emission Fault nucleation Drainage condition
ISSN号	0013-7952
DOI	10.1016/j.enggeo.2021.106254
英文摘要	To investigate the effect of water on the fracture mechanism and associated acoustic emission (AE) characteristics, triaxial compression experiments were performed on dry and water-saturated tight sandstone specimens sampled from the Sichuan Basin, China. The saturated specimen was precisely controlled by different drainage conditions at the two ends. The detailed spatiotemporal distribution of AE activities and the P-wave velocities were used to examine the initiation and propagation of microcracks, as well as fault nucleation process. There are significant differences in mechanical behavior, P-wave velocity, AE activities, and fault nucleation between the dry and saturated specimens. The mechanical behavior of the saturated specimen is characterized by water weakening, with 10% and 26% reductions in peak strength and elastic modulus, respectively, in comparison with those for the dry specimen. Water enhances inelastic axial deformation and strain softening. The evolution of Pwave velocity is associated with microcracking-induced dilatancy. The decrease in P-wave velocity is suppressed in the saturated specimen, especially at the drained end. Significant attenuation of AE energy is observed in the saturated specimen, resulting into a lower event rate compared with that for the dry specimen. It is shown that the saturated specimen has an extended fault nucleation duration and lower rupture velocity. The precursory phase of dynamic failure can be clearly mapped based on strain softening, accelerating AE event rate, and decreasing b-value, as well as decreasing pore pressure (in undrained condition) or increasing injection rate (in drained condition).
资助项目	National Natural Science Foundation of China[41902297] ; National Natural Science Foundation of China[41872210] ; Open Research Fund of the State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences[Z017006] ; Natural Science Foundation of Hubei Province[2018CFB292]
WOS研究方向	Engineering ; Geology
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000692696200014
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27897]
专题	中科院武汉岩土力学所
通讯作者	Li, Qi
作者单位	1.Chinese Acad Sci, Inst Rock & Soil Mech IRSM, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Natl Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058567, Japan
推荐引用方式 GB/T 7714	Li, Xiaying,Lei, Xinglin,Li, Qi. Fault nucleation of tight sandstone by investigation of mechanical, acoustic, and hydraulic responses[J]. ENGINEERING GEOLOGY,2021,292:9.
APA	Li, Xiaying,Lei, Xinglin,&Li, Qi.(2021).Fault nucleation of tight sandstone by investigation of mechanical, acoustic, and hydraulic responses.ENGINEERING GEOLOGY,292,9.
MLA	Li, Xiaying,et al."Fault nucleation of tight sandstone by investigation of mechanical, acoustic, and hydraulic responses".ENGINEERING GEOLOGY 292(2021):9.