Analysis And Study On Slope Seepage Stability Under Rainfall

Rainfall is one of the main causes of instability and failure of slope,slope sliding and rainwater infiltration and destruction are closely related,studies by many scholars at home and abroad pay attention to the important topic of the slope stability under rainfall condition.The slope of heavy rainfall or long time rainfall caused by damage caused a great loss to human life and property,the dynamic analysis of the temporal and spatial variation of slope seepage and stability in the process of rainfall has important significance for the research and prediction of slope stability.This paper is based on the saturated unsaturated seepage theory,analyzed the variation of slope seepage field under the condition of rainfall,the formation of rock and soil moisture,transient saturated zone and pore water pressure and dynamic changes,and analyzed the influence of rainfall and slope characteristics variation of slope seepage field;combined with Co.analysis of dynamic changes of seepage on slope stability calculation results and limit equilibrium method;then the influence factors on the slope seepage and stability sensitivity analysis.The specific research work is as follows:1.Theoretical study on saturated unsaturated seepage theory.Based on Darcy's law and the law of conservation of energy as the foundation,summarizes the saturated unsaturated seepage control equation,the boundary conditions are given under the condition of rainfall;transient saturated unsaturated differential equations with boundary conditions,the calculation basis for the follow-up finite element numerical simulation.2.Using finite element method to analyze the variation characteristics of slope seepage field under rainfall condition.This SEEP/W module by using two dimensional finite element software Geo-Studio to calculate the change of slope volumetric water content,pore water pressure under the condition of rainfall,and analyzed the influence for different rainfall intensity,rainfall duration,total rainfall,rainfall of different types on the change law of slope seepage field.Through calculation and analysis:in the process of rainfall infiltration is mainly affected by the surface soil slope,soil pore water increased,appeared transient saturated zone,and affected by the first slope surface,finally extends to the slope body.3.Calculation and analysis of the stability of the slope during rainfall.The SLOPE/W module of the application software Geo-Studio will calculate the results obtained by using the method of limit equilibrium method to analyze the dynamic changes of slope stability in the process of rainfall.The effects of different rainfall conditions and slope characteristics on the slope stability are also considered.The variation of slope safety coefficient:the safety coefficient of slope stability under rainfall conditions in different degree.The minimum safety factor sometimes does not appear in the rain stopped the moment,but lags behind;the rain stopped after the slope safety factor will slowly rise.4.Based on the engineering example,the stability of high slope under rainfall infiltration condition is analyzed.Using Geo-Studio software to analyze the seepage characteristics and the stability safety factor of the slope under the action of a heavy rainstorm and intermittent two times of heavy rainfall in Southwest China.