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DOI	10.1016/j.tecto.2019.228277
	Impact of fluid pressure on failure mode in shear zones: Numerical simulation of en-echelon tensile fracturing and transition to shear
	Okamoto A.; Fuse K.; Shimizu H.; Ito T.
发表日期	2020
ISSN	00401951
卷号	774
英文摘要	En-echelon veins are a set of tensile fractures that develop during the initiation of shear zones under certain conditions, but factors that control fracture patterns remain unclear. In this study, we performed numerical simulations using the two-dimensional distinct element method to understand the influence of effective normal stress on the development of fractures during shear deformation. At low effective normal stress (10 MPa), dilation takes place at an angle of ≈40°–45° to the shear boundary, and en-echelon arrays of tensile fractures develop. In contrast, at high effective normal stress (150 MPa), en-echelon veins are not developed, but a distinct shear plane forms. A transient behavior characterizes intermediate effective normal stress (≈50 MPa): early tensile cracks are generated and then propagate to form larger brittle faults. In this case, the larger strain energy released in the later stage is due to the greater shear strength. Under crustal conditions, effective normal stress varies, due to the change in fluid pressure. Our results suggest that en-echelon veins are indicators of high fluid pressure, close to lithostatic conditions, i.e. effective normal stress close to zero, and that a transition of the failure mode from tensile to shear could occur in response to a dynamic change of fluid pressure during fracturing. © 2019 Elsevier B.V.
关键词	Distinct element method Effective normal stress En-echelon vein Failure mode Fluid pressure Shear deformation
英文关键词	Failure modes; Numerical methods; Numerical models; Shear deformation; Strain energy; Transport properties; Distinct element methods; Effective normal stress; En-echelon vein; Fluid pressures; Fracture pattern; Tensile fractures; Transient behavior; Two-dimensional distinct element method; Fracture; computer simulation; deformation mechanism; effective stress; failure analysis; fluid pressure; fracture mechanics; numerical model; shear zone; stress field; tensile strength; two-dimensional modeling
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207837
作者单位	Graduate School of Environmental Studies, Tohoku University, Japan, 6-6-20 Aramaki-aza-Aoba, Aoba-ku, Sendai, 980-8579, Japan; Institute of Fluid Science, Tohoku University, Japan, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan; Geotechnical Analysis Group, Advanced Analysis Department, Civil Engineering Design Division, Kajima Corporation, Japan, 6-5-30 Akasaka, Minato-ku, Tokyo, 107-8502, Japan
推荐引用方式 GB/T 7714	Okamoto A.,Fuse K.,Shimizu H.,et al. Impact of fluid pressure on failure mode in shear zones: Numerical simulation of en-echelon tensile fracturing and transition to shear[J],2020,774.
APA	Okamoto A.,Fuse K.,Shimizu H.,&Ito T..(2020).Impact of fluid pressure on failure mode in shear zones: Numerical simulation of en-echelon tensile fracturing and transition to shear.Tectonophysics,774.
MLA	Okamoto A.,et al."Impact of fluid pressure on failure mode in shear zones: Numerical simulation of en-echelon tensile fracturing and transition to shear".Tectonophysics 774(2020).