Bulk solids commonly segregate when particles move on an inclined surface, often causing significant variations in content uniformity of particle properties such as size and species. Often called free surface rolling segregation, this is one the most common segregation phenomena for powders granules, where different sized shaped become separated due to differential movement surface. Intensity w...

Granular simulations are used to probe the particle scale dynamics at short, intermediate, and long time scales for gravity-driven, dense granular flows down an inclined plane. On approach to the angle of repose, where motion ceases, the dynamics become intermittent over intermediate times, with strong temporal correlations between particle motions-temporally heterogeneous dynamics. This interm...

An intriguing feature of granular matter is the close coexistence of solid-like regions and liquid-like flows. We study steady, fully-developped, granular flows confined between parallel vertical sidewalls. The sidewall friction stabilizes the underlaying heap at an inclination exceeding the angle of repose and increasing with flow rate. Our experiments reveal, in agreement with numerical simul...

Selected physical properties of jointed goatgrass samples collected in western Nebraska and eastern Colorado were determined. Measured properties were spikelet dimensions (length 10.8 ± 0.35 mm; width 2.59 ± 0.25 mm), particle density (0.761 ± 0.016 g/m3), bulk density (351 ± 26.9 kg/m3), terminal velocity (301 ± 25.9 m/min), angle of repose (26.3 ± 0.286°), internal coefficient of friction (0....

[1] Accumulations of rocky debris at the base of bedrock escarpments on Mars have mean inclinations of 20 , well below the angle of repose ( 35 ). These inclinations decrease with increasing latitude, suggesting a climatic influence. We present evidence that these low inclinations are the result of gravitational creep driven by repeated deposition and sublimation of ground ice. We estimate the ...

An experimental study of a binary granular mixture submitted to a transient shear flow in a cylindrical container is reported. The formation of ripples with a spiral shape is observed. The appearance of phase segregation in those spiral patterns is shown. The relative grain size bewteen sand species is found to be a relevant parameter leading to phase segregation. However, the relative repose a...

We investigate the gravity driven rapid failure of a granular step composed of non-cohesive steel beads. The step is initially held together with electromagnets, and released when the current is switched off. We visualize the surface and the motion of the grains during the entire relaxation. The initial failure occurs at the surface and the subsequent flow is also confined to the surface as the...