天山雪崩动力学研究新进展

NEW PROGRESS IN THE RESEARCH ON AVALANCHE DYNAMICS IN THE TIANSHAN MOUNTAINS, CHINA

中日合作雪崩动力学研究在我国天山西部进行。结果表明，雪崩前锋速度7．1m／s，雪崩冲击力是雪崩雪高度的函数，其最大冲击力为88．7kPa，出现在雪崩雪1．45m高度。雪崩雪分为两层：上层为雪云，下层为密雪流。密雪流表面呈现下倾形态向下运动。

In order to investigate the dynamic features of avalanches, a China-Japan joint research project was carried out in the western area of the Tianshan Mountains, Xinjiang,China. A pylon of 5 m in height was installed near the lower center of an avalanche path in a medium size. There were six pressure transducers and two load cells at intervals on the pylon, which were used for measuring avalanche velosities and impact pressures. In spring of 1996, the instruments were impacted by an artificially relcased avalanche,and some related data were recorded by the instruments. The results show that the avalanche speed at the front was 7.1m / s. The avalanche impact pressures are the functin of avalanching snow heights. The maximum impact pressure of 88.7kPa was recorded at the leve1 of 1.45m. The avalanching snow was consisted of two layers: snow cloud and dense snow flow. The top of the snow cloud was as high as 5 m at least. The boundry between the snow cloud and dense snow flow was varied from 1.75 m to 2.25 m in height, Calculated density of the avalanching snow was 184kg/ m^3. The surface of the dense snow now declined towards the downstream.