关键词: 高速远程滑坡, 流化床, 石英颗粒, 供风量, 床层压降, 流态化

Abstract: For the study of the flow behavior of rock avalanches under the effect of entrapped air, the Xiejiadianzi rock avalanche is studied with a series of experiments, equipped with a fluidized bed designed by authors. Based on the experimental data, the following results are reached: (1) For materials having wide grain size distribution (ranging from 0.1 to 7 mm), sharp irregular shapes, and high fine-grain content at its lowest part, an obvious bubbling control characteristic, not a linear increasing trend, is displayed as the quantity of air increases. Variation of the positions of bubbles or the air cushion layer causes significant differences in bed pressure drops. (2) When air quantity is low, the deposit presents a high stability with limited air holes observed. As the increase of air quantity, the fluidization intensity of the deposit increases obviously with some fluidization characteristics observed, such as dense sandy cloud, air holes, and ridges, which are similar to the phenomena observed in field rock avalanche deposits. (3) For such irregular shaped debris, bridging phenomenon is easy to form, which can strengthen the stability of deposit and prevent the escape of entrapped air. When air quantity is high enough, an air cushion effect can be observed at the bottom of deposit with air born system formed.

Key words: rock avalanches, fluidized bed, quartz grain, air quantity, bed pressure drop, fluidization