Particle size effects on small-scale avalanches and a μ(I) rheology-based simulation

Abstract In this paper, we introduce the μ(I) rheology into the traditional depth-averaged continuum framework and include the effect of grain size when describing the normal stresses of a flowing avalanche. We also develop a set of experimental installations for granular flow and use the installations to simulate laboratory avalanches: sand initially accumulates in various geometries, is then released and slides on inclined planes at different angles of inclination, and is finally deposited on a horizontal plane. The experimental materials are sand with different particle sizes. With the combination of the experimental and simulation results, the effects of particle size on the deposit configuration, runout distance, and deposit depth are revealed. The effect on the runout distance decreases with the angle of inclination, while the effect on the deposit depth is not obvious. Other factors such as the initial accumulation geometry and frictional parameters of the μ(I) rheology are carefully considered and studied.