Multiscale Analysis of the Stress State in a Granular Slope in Transition to Failure

Abstract

By means of contact dynamics simulations, we analyze the stress state in a granular bed slowly tilted towards its angle of repose. An increasingly large number of grains are overloaded in the sense that they are found to carry a stress ratio above the Coulomb yield threshold of the whole packing. Using this property, we introduce a coarse-graining length scale at which all stress ratios are below the packing yield threshold. We show that this length increases with the slope angle and jumps to a length comparable to the depth of the granular bed at an angle below the angle of repose. This transition coincides with the onset of dilatation in the packing. We map this transition into a percolation transition of the overloaded grains, and we argue that in the presence of long-range correlations above the transition angle, the granular slope is metastable.

arXiv comment11 pages, 14 Fig, submitted to PRE

References in corpus (4)

• Turbulent-like fluctuations in quasistatic flow of granular media
• Pre-avalanche instabilities in a granular pile
• The Origin of a Repose Angle: Kinetics of Rearrangements for Granular Materials
• Jamming transition of a granular pile below the angle of repose

Cited by in corpus (8)

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• Stress transmission in wet granular materials
• Particle-scale origins of shear strength in granular media
• Memory of the Unjamming Transition during Cyclic Tiltings of a Granular Pile
• Noise Amplification in Frictional Systems: Oscillatory Instabilities
• Local Coulomb versus Global Failure Criterion for Granular Packings
• Influence of Rotations on the Critical State of Soil Mechanics
• Transmission des forces dans un milieu composé de grains non sphériques