Dynamics of Snow Avalanche (With Estimation for Force on a Bridge)

Critical conditions for the occurrence of snow avalanches are first reviewed and summarized. Physical descriptions of slab avalanche, powder avalanche and mature powder avalanche are given. A two-dimensional dynamic model based on a fluid mechanics principle to describe snow avalanche is introduced. The vertical distribution of pressure forces above ground are estimated from this model based on some of the empirical relationships determined by A. Voellmy [18]. Finally, the estimations of the anticipated forces by a snow avalanche on a proposed bridge are given.