Incipient failure in sandpile models

TL;DR

This paper compares elastoplastic and constitutive models for sandpiles, revealing both predict the same failure condition at the pile's edge, and suggests experimental tests to validate these predictions.

Contribution

It demonstrates that different theoretical approaches yield the same failure prediction in sandpiles and proposes experimental validation methods.

Findings

Both models predict failure at the pile's edge.

The models produce identical failure predictions.

Experimental tests are proposed for validation.

Abstract

Elastoplastic and constitutive equation theories are two approaches based on very different assumptions for creating a continuum theory for the stress distributions in a static sandpile. Both models produce the same surprising prediction that in a two dimensional granular pile constructed at its angle of repose, the outside wedge will be on the verge of failure. We show how these predictions can be tested experimentally.