Benchmarking Exercises for Granular Flows

TL;DR

This paper evaluates a numerical model for granular flows through benchmarking exercises, demonstrating its ability to reproduce field observations and analytical solutions, while highlighting limitations in predicting natural landslide behaviors.

Contribution

The study provides a comprehensive benchmarking of a granular flow model, assessing its accuracy and limitations in reproducing both theoretical and natural cases.

Findings

Model reproduces observations at field scale

Calibrated friction angles align with other models

Model shows very low numerical dissipation

Abstract

For the 2007 International Forum on Landslide Disaster Management framework, our team performed several numerical simulations on both theoretical and natural cases of granular flows. The objective was to figure out the ability and the limits of our numerical model in terms of reproduction and prediction. Our benchmarking exercises show that for almost all the cases, the model we use is able to reproduce observations at the field scale. Calibrated friction angles are almost similar to that used in other models and the shape of the final deposits is in good agreement with observation. However, as it is tricky to compare the dynamics of natural cases, these exercises do not allow us to highlight the good ability to reproduce the behavior of natural landslides. Nevertheless, by comparing with analytical solution, we show that our model presents very low numerical dissipation due to the discretization and to the numerical scheme used. Finally, in terms of mitigation and prediction, the different friction angles used for each cases figure out the limits of using such model as long as constitutive equations for granular media are not known.