Effects Of Rain Infiltration On Numerical Simulation Of SeePage And Stability Analysis Of Slope

The stability problem of slopes under rainfall involves not only the saturated-unsaturated seepage law,but also the effect of water contect changes on the intensive parameter of unsaturated soil.For different the soil characteristics,the Seepage and stability of slope under rainfall is analyzed.Based on the saturated-unsaturated seepage theory and rainfall infiltration theory,the change of seepage fields is analyzed.On the basis of calculated transient seepage field and the shear strength theory of unsaturated soil,the transient stability of slope is analyzed.The main conclusions are as follows:1 The saturated-unsaturated seepage theory under rainfall condition and the governing equation of unsaturated seepage are introduced.The boundary conditions are attained.2 The FEM format of saturated-unsaturated seepage differential equation is drawed based on Galerkin's method of weighted residual.For the different property soil,pore water pressure field under different rainfall conditions are calculated by adopting FEM model of simple earth slope using SEEP/W flow calculation procedures.The impacts of seepage field under the varies with rainfall intensity,duration of rainfall,rain type,soil permeability coefficients and slope angle are discussed.3 The basal theory of saturated-unsaturated slopes' stability is introduced. Regarding rainfall seeping as an important factor of soil slope stability analysis,the distribution of pore water pressure of seepage field is calculated and introduced into the formula of safety factor useing GEO-SLOPE(SLOPE/W module)sofeware.The impacts of non-saturated slope stability are quantitatively drawed under the influence of rainfall and slope gradient;the varies of parameters are discussed on the impact of slope safety and the stability of the slope is evaluated.The results show that in most parts of Gansu slope gradient have a greater impact on the stability of slope than rainfall;under the possible rainfall conditions,the slopes of more than 65~0 slope gradient are considered supporting.