Creeping snow: modelling the force induced on structures

Climate change is causing snow pack mechanical characteristics to change, with an influence on snow creep. The resulting lower stability of snow packs on slopes leads to higher interaction forces with mitigation structures, as demonstrated by the increasing number of snow rack failures. The ultimate goal of the project is to enable the design of more robust structures for stabilising snow by developing a novel, adaptable 3D modelling tool for simulating forces on mitigation structures.

The model will account for different mechanisms of interaction between snow and the structures. The scientific novelty comes from the coupling between two types of numerical modelling for capturing the salient characteristics of the creeping snow: Discrete Element Method (DEM) near the structure and Smoothed Particle Hydrodynamics (SPH) in the far field.

The main objectives of the project are:

• To develop a new coupled 3D SPH-DEM numerical method, that can capture fundamental mechanical interactions of snow-structure interaction in a computationally-feasible manner
• To evaluate the model using field data available to INRAE-ETNA
• To undertake a parametric study to attain a mechanically-based understanding of interactions between (i) dry and (ii) wet creeping snow packs with obstacles.

One of the main scientific challenges to be tackled is to develop and evaluate the properties of the DEM model for different types of snow, including the contact law, the size and shape of the aggregates being modelled, and the viscous properties relevant to creep; as well as identifying suitable rheological laws for the SPH model.