Strength Tests on Newly Fallen Snow

• Published in: Journal of Glaciology
• Main Author: Perla, R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1969
• Subjects: Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/s0022143000027015; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000027015

Abstract Modified versions of in situ strength tests previously applied to metamorphosed snow were developed to measure the mechanical properties of newly fallen snow during storm periods. A large drop-cone penetrometer, protected from the wind by an aluminum shell, was used to determine snow “hardness”. A lightweight model of the Haefeli ram penetrometer measured “ram numbers”. Shear strengths were obtained from large, light-weight frames. Some preliminary tests were made with a shear vane driven by a torque wrench. A new technique was devised for measuring tensile strength whereby a cantilever beam of snow is undercut until it fails under its own weight. Comparisons between the cantilever test and the shear-frame test show high ratios for tensile to shear strength. Cantilever strength plotted against density shows an order of magnitude variation in strength at all densities.