Mixtures of small rigid sand particles Ds and large soft rubber particles Dr are prepared at different volume fractions and tested to investigate their small-strain and zero-lateral strain responses (Dr /Ds & 10). Both data sets are simultaneously gathered in an oedometer cell instrumented with bender elements. Data are analyzed in the context of mixture theory and with the aid of numerical sim...

Singing dunes, which emit a loud sound as they avalanche, constitute a striking and poorly understood natural phenomenon. We show that, on the one hand, avalanches excite elastic waves at the surface of the dune, whose vibration produces the coherent acoustic emission in the air. The amplitude of the sound (approximately 105 dB) saturates exactly when the vibration makes the grains take off the...

We conducted GDS dynamic triaxial tests to study the change rules of hysteresis curve morphology, axial strain, elastic modulus, and damping ratio waste tire rubber-mixed sand-based subgrade model samples with different rubber particle sizes, mixing amounts, loading times. The research revealed developmental rule curves rubber-mixed-sand under cyclic loading. From analyses comparison stress–str...

The spatio-temporal evolution of a downsized model for a desert dune is observed experimentally in a narrow water flow channel. A particle tracking method reveals that the migration speed of the model dune is one order of magnitude smaller than that of individual grains. In particular, the erosion rate consists of comparable contributions from creeping (low-energy) and saltating (high-energy) p...

[1] In this study we incorporate the existing concept of fractional mobility into a stochastic framework for modeling the partial transport of mixed-size sediment. The model predicts the fractional transport rates with parameters such as the long-run moving probability, mean particle velocity, and fractional mobility, all varying with the dimensionless effective shear stress. Movement of bed lo...

If you walk on sand, it supports your weight. How do the disordered forces between particles in sand organize, to keep you from sinking? This simple question is surprisingly difficult to answer experimentally: measuring forces in three dimensions, between deeply buried grains, is challenging. Here we describe experiments in which we have succeeded in measuring forces inside a granular packing s...