Simulations of dense snow avalanches on deflecting dams

Abstract

Two models simulating snow avalanches impacting retaining dams at oblique angles of incidence are presented. First a lumped mass model applying the Voellmy-Perla equation is used to calculate the path ofthe centre-of-mass along the side of a retaining dam. Secondly a one-dimensional continuum model applying depth-integrated equations of balance of mass and linear momentum, is expanded to take into account that real avalanche flows are threedimensional. The centre line of the avalanche path is determined by the flowing material as it progresses down the channelized avalanche path. The non-linear constitutive equations comprise viscosity, viscoelasticity and plasticity. Both models are calibrated by simulations of a registered avalanche following a strongly curved channel. The path and the run-up height ofthe avalanche on the natural deflecting dam with oblique angle ofincidence as calculated by the two models, are compared with the observations made.