Item: The cantilever beam or
Title: The cantilever beam or
Proceedings: Proceedings of the 1998 International Snow Science Workshop, Sunriver, Oregon
Authors: Craig Sterbenz, Snow Safety Director, Telluride Ski & Golf Co., Telluride, CO.
Abstract: Weak layers buried within the snowpack are chiefly responsible for slab avalanche formation. These weak layers tend to fail in shear when subjected to internal snowpack stresses. There are myriads of snow stability tests used to locate and quantify the weakness of these shear layers. Knowledge gained from these shear tests forms the basis for most avalanche forecasting programs. However, the relationship between stress and strength within the snowpack remains complex and important. Stress must equal or exceed strength for failure and avalanche release. The shear fracture within the weak layer must also precipitate tensile failure of the overlying slab for avalanche release to occur. Because the weak layers are so important for avalanche formation, little has been done to evaluate the strength of the slab layer. The "Bridgeblock" or cantilever beam test is a simple field test designed to evaluate the tensile strength of the slab material overlying the bed surface weakness.
Keywords: avalanche forecasting, avalanche formation, snow mechanics, snow hardness, snow strength
Digital Abstract Not Available