DOI: 10.1016/j.epsl.2020.116481
论文题名: Plate motion in sheared granular fault system
作者: Gao K. ; Guyer R.A. ; Rougier E. ; Johnson P.A.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 548 语种: 英语
中文关键词: 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
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/164973
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
Gao K.,Guyer R.A.,Rougier E.,et al. Plate motion in sheared granular fault system[J]. Earth and Planetary Science Letters,2020-01-01,548