Determination of the Principal Stresses of a Snow Cover on a Mountain Slope Using Snow Pressure Gauges

Abstract

Principal stresses in a snow cover on a uniform slope were determined by two methods, each using thin pressure gauges to measure snow pressure in the snow. These snow pressures were principal stress σ2 on a vertical plane perpendicular to the contour lines and normal compressive stress σ θ on a plane perpendicular to the vertical plane. In addition, plastic Poisson’s ratio v was estimated in a snow cover on level ground. Estimates of principal strain rates were used to calculate principal stresses and viscosity by two different methods, using estimates of v and the constitutive equations of Yosida (1980) and the derived values of σ2and σθ. For dry and compact snow, σ1 and σ3 calculated by both methods agreed well with each other, and also with values obtained by the hole-mark method reported by Shimizu and Huzioka (1975).