气候变化领域集成服务门户(CCPortal): Plate motion in sheared granular fault system

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DOI	10.1016/j.epsl.2020.116481
	Plate motion in sheared granular fault system
	Gao K.; Guyer R.A.; Rougier E.; Johnson P.A.
发表日期	2020
ISSN	0012821X
卷号	548
英文摘要	Plate motion near the fault gouge layer, and the elastic interplay between the gouge layer and the plate under stick-slip conditions, is key to understanding the dynamics of sheared granular fault systems. Here, a two-dimensional implementation of the combined finite-discrete element method (FDEM), which merges the finite element method (FEM) and the discrete element method (DEM), is used to explicitly simulate a sheared granular gouge fault system. We focus on investigating the influence of normal load, driving shear velocity and plate stiffness on the velocities and displacements in the direction parallel to the shear direction (x-direction) measured at locations on the upper and lower plates just adjacent to the gouge. The simulations show that during slip phases the magnitudes of the measured velocities on the upper and lower plates are proportional to the normal load and may be inversely proportional to the square root of the plate's shear modulus. Whereas, the driving shear velocity does not show distinct influence on the measured velocities. Additionally, large slip velocities are generally associated with large macroscopic friction coefficient drops. For the models subjected to smaller normal loads, larger shear velocities and with stiffer shear plates, the same magnitude of slip velocity could cause a larger drop of macroscopic friction coefficient. During stick phases, the velocities of the upper and lower plates are respectively slightly greater and slightly smaller than half of the driving shear velocity and are both in the same direction of shear. The shear strain rate of the gouge is calculated from this velocity difference between the upper and lower plate during stick phases and thus the gouge effective shear modulus can be calculated. The results show that the gouge effective shear modulus increases proportionally with normal load, while the influence of shear velocity and plate stiffness on gouge effective shear modulus is minor. The simulations address the dynamics of a laboratory-scale fault gouge system and may aid in revealing the complexities of earthquake frictional dynamics. © 2020 Elsevier B.V.
关键词	combined finite-discrete element method (FDEM)fault friction fault gouge shear modulus fault motion granular fault gouge stick-slip
英文关键词	Drops; Elastic moduli; Finite difference method; Shear strain; Slip forming; Stick-slip; Stiffness; Strain rate; Velocity; Effective shear modulus; Frictional dynamics; Macroscopic friction; Shear direction; Shear velocities; Slip velocity; Stick-slip condition; Velocity difference; Shear flow; discrete element method; displacement; fault gouge; fault zone; finite element method; granular medium; plate motion; shear modulus; stiffness
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202595
作者单位	Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China; Geophysics, Los Alamos National Laboratory, Los Alamos, NM 87545, United States; Department of Physics, University of Nevada, Reno, NV 89557, United States
推荐引用方式 GB/T 7714	Gao K.,Guyer R.A.,Rougier E.,et al. Plate motion in sheared granular fault system[J],2020,548.
APA	Gao K.,Guyer R.A.,Rougier E.,&Johnson P.A..(2020).Plate motion in sheared granular fault system.Earth and Planetary Science Letters,548.
MLA	Gao K.,et al."Plate motion in sheared granular fault system".Earth and Planetary Science Letters 548(2020).