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.