(State Key Laboratory of Geological Hazard Prevention and Geological Environment Protection，Chengdu University of Technology，Chengdu，Sichuan 610059，China)
Abstract：A large number of experimental results indicate that the content of the fine particles has fairly influence on the shear strength of granule. With the increase of the content of fine particles，granular shear strength gradually declines. Combined with in-situ investigation of the talus slope located in Tianshan highway and indoor physical simulation experiment results，it is found that fine granular layer plays controlling role in the large-scale failure process，and a three layers granular structural mode which is composed of loose granular layer，fine granular layer and frictional layer is proposed. Moreover，a new large-scale failure model，which takes on a whole failure characteristic is constructed. The kinetic mechanism of one slump is as follows：as a result of fine particle layer material，the shear strength is relatively low，the talus slope will accumulate large-scale slump along the fine particle layer，which is similar to the instability characteristics of landslide under the strong disturbance of various dynamic loads.
