Thermal and force-chain effects in an experimental, sloping granular shear flow
Article first published online: 13 MAY 2008
Copyright © 2008 John Wiley & Sons, Ltd.
Earth Surface Processes and Landforms
Volume 33, Issue 13, pages 2108–2117, November 2008
How to Cite
Furbish, D. J., Schmeeckle, M. W. and Roering, J. J. (2008), Thermal and force-chain effects in an experimental, sloping granular shear flow. Earth Surf. Process. Landforms, 33: 2108–2117. doi: 10.1002/esp.1655
- Issue published online: 29 OCT 2008
- Article first published online: 13 MAY 2008
- Manuscript Accepted: 29 NOV 2007
- Manuscript Revised: 22 NOV 2007
- Manuscript Received: 7 SEP 2007
- granular flow;
- force chain;
- sediment transport
Force chains figure prominently in shearing motions of granular materials, inasmuch as these chains of load-bearing grains dominate resistance to motion. A simple scaling of the forces involved in the motion of a dry, gravity-driven granular shear flow induced by vibrations (see, e.g., Roering et al., 2001; Roering, 2004) suggests that this shearing motion reflects a balance between the rate of production and the rate of disruption of granular force chains. The rate of production of force chains is proportional to the rate of shear. The rate of disruption is proportional to the rate of shear as force chains ‘age’ during rotation, whence they become unstable and self-destruct. The rate of disruption is also proportional to the frequency and intensity of elastic waves, induced by acoustic vibrations, that propagate through the granular material and weaken force chains. The analysis is empirically consistent with the exponential-like profiles of grain displacement, and the strongly nonlinear increase in grain flux with increasing surface slope, observed in experiments. Copyright © 2008 John Wiley & Sons, Ltd.