Three-dimensional discrete element modeling of triggered slip in sheared granular media.
This paper reports results of a three-dimensional discrete element method modeling investigation of the role of boundary vibration in perturbing stick-slip dynamics in a sheared granular layer. The focus is on the influence of vibration within a range of amplitudes and on the fact that above a threshold early slip will be induced. We study the effects of triggering beyond the vibration interval and their origins. A series of perturbed simulations are performed for 30 large slip events selected from different reference runs, in the absence of vibration. For each of the perturbed simulations, vibration is applied either about the middle of the stick phase or slightly before the onset of a large expected slip event. For both cases, a suppression of energy release is on average observed in the perturbed simulations, within the short term following the vibration application. For cases where vibration is applied in the middle of the stick phase, a significant clock advance of the large slip event occurs. In the long term after vibration, there is a recovery period with higher-energy release and increased activity in the perturbed simulations, which compensates for the temporary suppression observed within the short term.
Swiss Federal Institute of Technology Zürich, Stefano-Franscini-Platz 5, CH-8093 Zürich, Switzerland and Swiss Federal Laboratories for Materials Science and Technology, ETH Domain, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
Behrooz
B
Ferdowsi
Swiss Federal Laboratories for Materials Science and Technology, ETH Domain, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
Michele
M
Griffa
Solid Earth Geophysics Group, Los Alamos National Laboratory, MS D446, Los Alamos, New Mexico 87545, USA and Department of Physics, University of Nevada, Reno, Reno, Nevada 89557, USA.
Robert A
RA
Guyer
Solid Earth Geophysics Group, Los Alamos National Laboratory, MS D446, Los Alamos, New Mexico 87545, USA.
Paul A
PA
Johnson
Department of Geosciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA and G3 Centre and Energy Institute, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Chris
C
Marone
Swiss Federal Institute of Technology Zürich, Stefano-Franscini-Platz 5, CH-8093 Zürich, Switzerland and Swiss Federal Laboratories for Materials Science and Technology, ETH Domain, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
Jan
J
Carmeliet