A Depth-Averaged Material Point Method for Shallow Landslides: Applications to Snow Slab Avalanche Release

TL;DR

This paper introduces a depth-averaged Material Point Method (DAMPM) for efficient simulation of shallow landslides, demonstrated on snow slab avalanches, with potential applications in hazard assessment and modeling various geophysical flows.

Contribution

The paper develops a novel depth-averaged MPM tailored for shallow landslides, enabling efficient large-deformation modeling over complex terrains, validated against classical experiments.

Findings

DAMPM accurately reproduces snow fracture experiments

Large-scale simulations reveal avalanche release zones

Model offers computational efficiency for hazard assessment

Abstract

Shallow landslides pose a significant threat to people and infrastructure. While often modeled based on limit equilibrium analysis, finite or discrete elements, continuum particle-based approaches like the Material Point Method (MPM) have more recently been successful in modeling their full 3D elasto-plastic behavior. In this paper, we develop a depth-averaged Material Point Method (DAMPM) to efficiently simulate shallow landslides over complex topography based on both material properties and terrain characteristics. DAMPM is an adaptation of MPM with classical shallow water assumptions, thus enabling large-deformation elasto-plastic modeling of landslides in a computationally efficient manner. The model is here demonstrated on the release of snow slab avalanches, a specific type of shallow landslides which release due to crack propagation within a weak layer buried below a cohesive slab. Here, the weak layer is considered as an external shear force acting at the base of an elastic-brittle slab. We validate our model against previous analytical calculations and numerical simulations of the classical snow fracture experiment known as Propagation Saw Test (PST). Furthermore, large scale simulations are conducted to evaluate the shape and size of avalanche release zones over different topographies. Given the low computational cost compared to 3D MPM, we expect our work to have important operational applications in hazard assessment, in particular for the evaluation of release areas, a crucial input for geophysical mass flow models. Our approach can be easily adapted to simulate both the initiation and dynamics of various shallow landslides, debris and lava flows, glacier creep and calving.