Analysis On The Influence Of Rainfall Characteristics On The Stability Reliability Of Unsaturated Slope

The landslides are common natural disasters. In recent years, they haved been caused by rainfall happened from time to tome, caused the people’s life and property great damage. Studying the rainfall characteristics how influences on slope stability has an important guiding significance for the prediction and prevention of landslide. In addition, because of natural soils after deposition and deposition process, load historical conditions, physical weathering processes, Chemical weathering processes and natural handling, these lead to physical and mechanical parameters of soil presents spatial variability.Under the condition of rainfall, slopes loss stability are fundamentally due to pore water pressure increasing, the matrix suction decreasing, and thus the shear strength declines. In this paper, use the extension of unsaturated soil Mohr-Coulomb shear strength theory to consider the effect of matrix suction on the slope stability and use Van Genuchten model to fitting the soil slope of soil water characteristic curve.In this paper, the Geostudio software is uesed to establish the analysis model of the rainwater infiltration tostudy the physical process of slope lossing stability, Then uses the analysis model for the study of the related parameters analysis. MATLAB and C# are used to compiled respectively based on Latin Hypercube Sampling Midpoint method in discrete random field and replacement program with Geostudio parameter Settings file. Under the condition of rainfall, analysis on how the random field features affect slope stable reliability index.This paper’s analysis showed that:①Under rainfall infiltration, the shear strength is reduced, the safety coefficient decreases, and stable reliability decreases. the rainfall intensity, rainfall time, rainfall type and different distribution of saturated infiltration coefficient have a significant influence on slope stability.②The slope reliability decreases with the increase of shear strength parameters of horizontal and vertical distance. Among them, vertical correlation distance of shear strength parameters influencing on reliability is greater than the influence of the horizontal correlation distance. relability index decreases with the increase of the correlation or variability. In this example of paper, the reliability index using random variable model to calculate is less than it using random field model.③Random field distribution of c influencing on the shape of the landslide is greater than the random field distribution of j.