Item: Basal stress measurements of artificial avalanches
Title: Basal stress measurements of artificial avalanches
Proceedings: Proceedings of the 1998 International Snow Science Workshop, Sunriver, Oregon
Authors: Kenji Kosugi, Osamu Abe, Atsushi Sato, Yasuaki Nohguchi, Kouichi Nishiniura, Yoichi Ito, Masaki Nemoto and Kaoru Izumi, Shinjo Branch of Snow and Ice Studies, National Research Institute for Earth Science and Disaster Prevention (NIED), Shinjo, Japan
Abstract: Measurements of basal stress of artificial snow avalanches and table tennis ball avalanches in motion were carried out with drag meters at a ski jump and an experimental chute. A mass of snow of which weight was 92 kg at maximum was released at the top of the ski jump slope to produce a snow avalanche. The normal and tangential components of the basal stress exerted on the slope by the avalanches were recorded with a drag meter installed at the lower end of the slope. The basal stress increased rapidly when the head of an avalanche reached the drag meter. The dynamic friction coefficient of the head was relatively small, ranging 0.2 to 0.6. From the middle to the tail of the avalanche, the basal stress decreased and the dynamic friction coefficient increased from 0.4 to 1.0. Basal stress measurements for avalanches of thousands of table tennis balls were also conducted at two points on the experimental chute. The basal stress increased and decreased monotonously during the pass of the avalanches at the upper point. At the lower point, the change in basal stress with time was similar to that obtained for snow avalanches mentioned above. The difference in the basal stress between the two points is probably caused by the change in the structure of the avalanche as it flows down.
Keywords: avalanche, snow, artificial avalanche, table tennis balls
Digital Abstract Not Available