3D modelisation of snow slabs stability.

Abstract

Snow slabs stability is a real problem to study in a mecanical point of view. A non exhaustive review of the different factors used to evaluate this stability or instability is done. All of them have been done in two dimensional cases, for an infinite constante slope and constant thickness of the snow cover. They are obtained by dividing a stress due to the snow pack weight by a snow hability. We present a numerical way for estimating the mecanical stability on any three dimensionnai slope. The mechanical stability factor is calculate with a stress strain 3D code using an elastoplastic behavior law for the snow. It considers a criteria of failure either in tension or in elasto-plasticity (Mohr Coulomb law) depending of the snow layer which fails. The application shown is a classic slab case and we are able to draw by the numerical calculation maps of a stability index in each layer, reproduces the phenomena generally observed in this case.