Study On The Characteristics Of Rain Infiltration And Its Influence On Slope Stability With Unsaturated Seepage Theory

The distribution of seepage field is one of the most important factors that affect the stability and deformation of slopes. And rainfalls, especially long-lasting and heavy rainstorms, induce landslides even more. In order to analyze the influence of rainfall on the unsaturated slopes' stability, in this paper, the change of seepage field in various soil slopes under the condition of rain infiltration is studied based on the saturated-unsaturated seepage theory. The following is include:1 .Fundamentals: Deducing the basic differential equation of saturated-unsaturated seepage in porous medium from fundamental physical equations. Explaining the fundamentals of saturated-unsaturated seepage and its different initial and boundary conditions.2. Analysis and study on the unsaturated seepage under the condition of rain infiltration, and to deduce the FEM format of unsaturated seepage differential equation and working-out its program.3.The Study on the parameters that affect the seepage field of unsaturated slopes based on the existent program of 3-D saturated-unsaturated seepage, mainly including(1) The combination of different rainfall intensity, duration, and type;(2) The essence of medium, e.g. the soil-water characteristic curve, the coefficient of saturated hydraulic conductivity and the initial state of medium;In the paper, the influence of rain infiltration on the slope stability is discussed , which is very helpful for forecasting slope stability in raining seasons and designing slopes in deep unsaturated zone.