Experimental factors affecting heap stability of binary granular mixtures

Abstract

The dependence of the stability of 3D granular heaps, quantified by their critical angle θ, on the nature of the granular materials and on the properties of the experimental setup is investigated. In a previous study we have shown the existence of supra maximal θ for bidisperse mixtures, i.e. θ greater than the θ of each component [M. Arciaga, et al. SPP 2007]. Here, we verify that θ values are increased with an increasing surface roughness of the granular materials. We also demonstrate experimentally that the mixtures' stability is lowly dependent on the size of the experimental setup and on the method of avalanche, but highly dependent on the speed of how the avalanche is induced.