Sensitivity Study On Influencing Factors Of Landslide Movement Process In Accumulation Layer

Landslide disaster is one of the most common natural disasters in China.In all types of landslide disaster,accumulation landslide accounts for a large proportion and is widely distributed,causing a large number of people and property losses every year.Landslide movement process evaluation is to determine the scope of the landslide disaster,the strength of foundation,and the current research about the process of accumulation landslide movement is less,not very clear,its controlling factors in the process of sports cause in the landslide risk assessment mechanism is not yet mature,in the practical engineering of accumulation landslide risk evaluation with the evaluation personnel experience mostly,The results are often subjective,which makes it difficult to prevent and control this kind of landslide.In order to explore the sensitivity of various influencing factors in the process of accumulation landslide movement,this paper made a statistical analysis on the parameter characteristics and influencing mechanism of the main influencing factors in the process of accumulation landslide movement from the perspectives of sliding path and accumulation body and combined with the investigation data of accumulation landslide in Chongqing.The material gradation of sliding body,slope,friction coefficient of sliding path and physical and mechanical properties of rock and soil are selected as the research objects.According to the material composition and physical and mechanical properties of Chejiaba landslide in Fengjie County,Chongqing,the landslide model is established by using PFC5.0 discrete element simulation software.On this basis,the control variable method is used to adjust the friction coefficient,slope,gradation,cohesion and other four factors to different levels,and the sensitivity of various influencing factors such as energy change,particle displacement,accumulation body shape and final slip distance in the process of landslide simulation is analyzed.The preliminary conclusion is that the sensitivity of the above four factors in descending order is slope,friction coefficient,gradation and cohesion.Considering the limitation of numerical simulation test,it may not be able to simulate all kinds of complex physical and mechanical mechanisms of landslide movement well,which leads to the deviation of final test results.This article through the design and build large landslide physical model to simulate the accumulation process of landslide,four factors three levels orthogonal experiment design scheme and the landslide of the groups of experimental maximum distance and movement speed as the dependent variable,to record the process of experiment,test and analysis,the final results are consistent with the results of numerical simulation,That is,slope has a significant influence on the landslide movement process and is the main controlling factor.The friction coefficient of sliding path has a significant effect on the final slip distance of the landslide.The effect of grade pairs on the movement distance of landslide is relatively small,and the physical and mechanical properties of sliding body have no obvious effect on the movement process of landslide.The research results can provide reference for the prediction of landslide sliding distance,sliding speed and disaster intensity and the establishment of risk assessment system.