Snow avalanche simulation and experiments

Avalanches and slides are gravity driven flows of slope-forming materials. Increased human activity in mountain regions, deforestation from pollution, forestry and ski resorts, as well as reduced acceptance of living in regions exposed to snow avalanches have caused a growing need for protection against avalanches. Such protection may be obtained by introducing different kinds of obstructions in the path of the avalanche or deflecting dams guiding the flow away from the sensitive areas. The purpose of the project is to study snow avalanches and landslides. The flowing dense snow in avalanches and rock, sand, and clay in slides have certain common characteristics reflected in the NIS material model developed and used at NGI in one- and tw o-dimensional simulations of avalanches and slides. In the present project the general material model will be implemented in a three-dimensional CFD code to provide a general simulation code. The code may be used in many different types of investigations of the consequences of avalanches and slides, such as the effects of deflecting and catching dams, and of impact on structures. The NIS model has six material parameters and the project aims at finding which of the parameters are important for different types of material, and the proper range of the parameters. Results from full-scale experiments with snow avalanches at NGI's test site Ryggfonn, and from laboratory tests using granular materials, will be used to find values of parameters for snow.