Viscoelastic analysis of stress waves through cohesive snow in layered and 2D configurations
- Verplanck, Samuel V. [ Montana State University: Civil Engineering ]
- Mckittrick, Ladean R. [ Montana State University: Civil Engineering ]
- Adams, Edward E. [ Montana State University: Civil Engineering ]
Dynamic surface loads generate stress waves in snow that can trigger slab avalanches. Previously, we determined Maxwell-viscoelastic model parameters from one-dimensional, homogeneous laboratory experiments resembling Compression Tests (CTs). Building off this, we extend the laboratory experiments and modeling effort to layered and two-dimensional configurations that resemble CTs and Extended Column Tests (ECTs) in flat terrain. Stress and acceleration data from 850 individual impacts are used to validate a finite element model. The model is then extended to domains beyond the laboratory geometries to explore stress wave behavior without a stiff lower boundary and finite widths. The results show that isolating a column, as is done in a CT and ECT, effectively creates a wave guide, altering the distribution of stress. The position of cohesive snow layers is also shown to affect the stress distribution by comparing 'softer' over 'harder' stratigraphy and vice versa. In a 'softer' over 'harder' configuration, modeled results indicate that both vertical-normal compressive stress and shear stress penetrate deeper below the layer interface. Above the interface, the modeled results show vertical-normal compressive stress is greater in a 'softer' over 'harder' configuration, while the shear stress is greater in the 'harder' over 'softer' configuration.