Acoustic Emission and Mechanical Properties of Snow Related to Avalanche Release.

摘要

The project was concerned with evaluation of the physical and mechanical processes associated with snow avalanche initiation. Four separate tasks were involved in this effort: (1) a stress wave study to evaluate the response of snow to transient loads, (2) a slope stability investigation to determine the effectiveness of boundary conditions on slope stability, (3) a material constitutive representation to evaluate material properties for loads characteristically found in snow slopes, and (4) an acoustic emission study to study the process of slab release. Considerable progress was achieved in all portions of the project. An electromagnetic stress wave generator was successfully constructed and tested and tests are now being carried out with this instrument. An equivalent linear viscoelastic model has been formulated for snow for densities, temperatures, and load conditions characteristic of alpine snow slopes. The acoustic emission field study is still gathering data, and a predictable pattern of acoustic emissions appears to be related to the process of fracture and avalanche initiation. The results of this one year project have been reported in seven publications and symposium presentations. (Author)