Experiment On Property Of Granular Fluidization Of Rock Avalanche Under Trapped Air

Rock avalanche is geological hazard with a sudden and powerful destructive force, behaves the huge volume, extraordinary high speed, long traveling distance, enormous energy and abnormally high liquidity etc.What occurs an important role on that rock avalanche transformed into dry debris flow, which leads to it move farther, is granular fluidization caused by trapped air. Niujuangou is the place where the epicenter of the Wenchuan earthquake located. As triggered by the earthquake, large volume of rock mass in the head of the Niuquangou gully was poured down within two minutes and then deposited on the right bank of the Minjiang. In this thesis the author focus on Niujuangou rock avalanche, has made the following works:(1) Investigate the geological conditions of Niujuangou rock avalanche and obtained field data;(2) Obtain basic physical and mechanics parameters of rock and soil through related labroatory rock and soil testing;(3) Grasp fluid dynamics feature of rock avalanche through experiment, i.e., critical value of granular fluidization of debris flow.By model test, the following conclusions can be drawn that:For the samples composed mainly by fine particles, the pressure changes regularly according with quantity of flow and exhibit a nearly linear growth. This kind of sample is easy to show granular fluidization. Keep the total path of overflow unchanged, the overflow of deposition increase when the density of granular materials reduce. Along with the decreasing of the total path of overflow, air overflow more easily, which means that the amount of trapped air is becoming less.