Experimental Study of Fluidized Landslide

Abstract

Fluidized landslides that travel long distances at high speed are one of the most dangerous types of landslides. A fluidized slope movement can occur in both artificially designed slopes and natural slopes and generally results in extensive property damage and significant loss of life. However, the initiation mechanisms triggering this type of landslide are still not clearly known. This study attempts to assess the initiation of fluidized landslides through data from flume tests. The samples were collected from the rock avalanches deposits in Wenchuan earthquake area of China, where many huge debris flows which were transformed from fluidized landslide were triggered after earthquake. With the installation of ultra-high sensitivity seismic accelerometers at the bottom of the flume, it was possible to record the vibrations induced by the movement of soil particles during the fluidization of the slope. It was found that just before the liquefaction of the slope, indicated by a sudden rise of pore water pressure, a vibration signal appeared which was weaker than the vibration signal caused by the subsequent movement of the slope. This signal was related to the instability of the soil assembly. Furthermore, the flume tests showed evidence of internal erosion, a phenomenon responsible for the instability of soil structures which can also play a key role in triggering fluidized landslides.