Couple Model Study Of Slope Runoff & Unsaturated Seepage Under Rainfall Condition

Landslide is one of the common geological hazards. A lot of landslides show that the failure of slope is always tied up with rainfall. So it is very important both in theory and application to engineering to make the mechanism of rainfall induced landslide clear. It is helpful to increasing the ability of landslide prevention and landslide prediction, and it is helpful to the soil conservation and the agricultural irrigation.This paper summarizes the theory of slope runoff & saturated -unsaturated seepage and the actuality of research, analyze the difficulties in this field. A new couple model of slope runoff & unsaturated seepage under rainfall condition was shown in the paper. The new couple model overcome the actual difficulties by calculating slope runoff and saturated -unsaturated seepage altogether, and make it possibly to research the rules of migration of water clearly under rainfall.According to the new couple model, the finite element form of the calculation model was shown in this paper. Base on the model, a four point 2-D FEM nonlinear code was compiled. Some examples are given in the paper to prove the correctness of the model. The result of slope runoff & saturated-unsaturated seepage under rainfall is completely consistent by the numerical method and the experimentation.A series of new method were put forward to solve the problems in the course of couple calculation. The results show that the method is more excellent than traditional method about the computational stability and the computational speedUsing the program, the influence of rainfall intensity, initial moisture content, slope angle and the abstraction of water to the overland flow and effluent seepage was analyzed. The result is completely consistent by the program and traditional theory.A program was compiled to provide data for the coupled calculation and to deal with the computational result. It is very useful for the coupled analysis.