AbstracL We present an implemenlalion of realistic static friction in molecular dynamics (MD) simulations of granular particles. In our model, to break contact between two particles, one has to apply a Bnile amount of force, determined by the Coulomb criterion. Using a Wo.dimmsional model, we show that piles generated by avalanches have a @e angle of repose 8, (finite slopes). Furthermore, thes...

The earth retaining structures frequently represent key elements of ports and harbors, transportation systems, lifelines and other constructed facilities. Earthquakes might cause permanent deformations of retaining structures and even failures. In some cases, these deformations originated significant damages with disastrous physical and economic consequences. For gravity walls, the dynamic eart...

In order to mitigate hazards of mass failure, the first step is the identification of potentially unstable slopes, resulting in a landslide susceptibility map. Satellite imagery is an important component in the derivation of critical parameters. Susceptibility maps can be constructed in a variety of ways, including multivariate statistics, heuristic models, and geotechnical models. Each method ...

Recent experiments by Baxter et al. showed the existence of density waves in granular material flowing out of a hopper. We show, using Molecular Dynamics Simulations, that this effect is a consequence of static friction and find that these density fluctuations follow a 1/f spectrum. The effect is enhanced when the opening angle of the hopper decreases.

We present results from numerical experiments testing the behavior of cohesionless gravitational aggregates experiencing a gradual increase of angular momentum. The test bodies used in these numerical simulations are gravitational aggregates of different construction, distinguished by the size distribution of the particles constituting them, parameterized in terms of the angle of friction (/). ...

To model cohesionless granular flow using continuum theory, the usual approach is to assume the cohesionless Coulomb-Mohr yield condition. However, this yield condition assumes that the angle of internal friction is constant, when according to experimental evidence for most powders the angle of internal friction is not constant along the yield locus, but decreases for decreasing normal stress c...

We present experiments showing that a granular system of small beads does exhibit ageing properties : its maximum stability angle is measured to increase logarithmically with resting time, i.e., the time elapsed before performing the measure. We show that humidity is the crucial ingredient responsible for this behaviour : while ageing effects are important at intermediate humidity, they disappe...