2021/11/01 by Fernando David Cúñez Benalcázar, Benalcázar, Fernando David Cúñez, Erick de Moraes Franklin +7 · 1 citation
Earth and Planetary Sciences · Environmental Science · #Geological formations and processes #Geology and Paleoclimatology Research #Landslides and related hazards
paper · pdf · doi:10.48550/arxiv.2111.01182
The critical fluid-shear stress for the onset of sediment transport, θc, varies with the history of applied shear. This effect has been attributed to compaction, but the role of shear jamming is unexplored. We examine the response of a granular bed to fluid-shear stress cycles of varying magnitude and direction, and determine isotropic and anisotropic contributions. Creep and bed-load transport result in direction-dependent strain hardening for θ/θc < 4. Dilation-induced weakening, and memory loss, occurs for larger stresses that fluidize the bed. Our findings provide a granular explanation for the formation and breakup of hard packed river-bed 'armor'.