Study On The Formation And Evolution Process Of Large Bedding Rock Landslides

Shanyang County is located on the southeast side of the Qinling Mountains,with complex and diverse topography and extremely complex geological structures.The rainfall is relatively large,and the seasonal rainfall is unevenly distributed.Extreme rainfall events are frequent.On the other hand,the areas where human engineering activities are relatively intense,under the combined influence of rainfall and human engineering activities,can easily cause geological disasters.The safety of the lives and property of the local people poses a great threat.Taking Shanyang Yanjiagou landslide as an example,this paper uses a scaled physical model test method to simulate the formation and evolution of the landslide.Through the analysis and discussion of the data collected during the experiment,the failure mechanism of the landslide is summarized.The research work and results are as follows:(1)Based on the physical size of the landslide and the size of the model box,according to the three similarity theorems,this test adopts the size similarity ratio Cl=130.After a series of ratio tests,it was determined that the ratio of each material of the sliding belt similar material is bentonite: talc powder: quartz sand: water=6:8:6:3;the ratio of each material of the sliding body similar material is barite powder: quartz sand: cement : Gypsum: Water=20:14:4:5:7;on the basis of reference to the predecessors,the dissolution fissures are prefabricated with wooden planks,and mortar blocks are used to simulate a sliding bed.(2)The water content,pore water pressure,earth pressure and displacement data are measured in the experiment,and the characteristics of landslide change and failure are analyzed.The experiment shows that with the beginning and end of the water injection process,the water content,pore water pressure and soil The pressure will rise and dissipate simultaneously,and there are certain differences in various indicators at different locations and different depths;various indicators will rise and fall suddenly when damaged;it reveals that the internal parameters of the landslide reach extreme values when the landslide is damaged,When the landslide is destroyed,the parameters return to the normal range.(3)According to the model test index changes and image information analysis and discussion,the landslide failure process in this experiment is divided into three stages: rainfall infiltration,mid-term creep and slip failure;its formation and evolution process are: joints,dissolution crack development-rainfall infiltration-local saturation-trailing edge tearing-crack development and expansion-slip resistance section shearing-overall slippage.