The shape of jamming arches in two-dimensional deposits of granular materials

TL;DR

This study experimentally investigates the shape and properties of arches in two-dimensional granular silos, revealing insights into frictional forces, arch geometry, and model limitations.

Contribution

It provides detailed measurements of arch properties and compares experimental data with numerical models, highlighting similarities and limitations.

Findings

Arches tend to have an aspect ratio close to one.

Frictional tangential forces influence arch formation.

Numerical models show both similarities and limitations compared to experiments.

Abstract

We present experimental results on the shape of arches that block the outlet of a two dimensional silo. For a range of outlet sizes, we measure some properties of the arches such as the number of particles involved, the span, the aspect ratio, and the angles between mutually stabilizing particles. These measurements shed light on the role of frictional tangential forces in arching. In addition, we find that arches tend to adopt an aspect ratio (the quotient between height and half the span) close to one, suggesting an isotropic load. The comparison of the experimental results with data from numerical models of the arches formed in the bulk of a granular column reveals the similarities of both, as well as some limitations in the few existing models.