Numerical Simulation On The Stability Of Bank Slope In Rainfall And Water Level Changes

Rainfall and the change of water level are the main factors of the slope failure. Rainfall and slope instability destructed human life and caused property heavy losses, so the study of stability of the slope, revealing the slope failure mechanism when the slope influenced by different factors such as rainfall and water level fluctuation. Controlling and forecasting landslide disaster have important practical significance. In this paper, the numerical model was established by Geo-Studio, separately researched the ideal bank slope and the Majiagou landslide in the Three Gorges reservoir under the different influence factors. Through the combination of seep/w and slope/w analysis, compare the results of the slope stability safety factors under the influence of different rate of water level fluctuation, the slope Angle, the soil strength parameters, the permeability coefficient and the rainfall intensity. Get the following conclusion:(1) Set up the saturated-unsaturated finite element model of the ideal bank slope, simulate to get the curve of the bank slope safety coefficient changing with time, compare the different influence factors about rate of water level fluctuation, the slope Angle, soil permeability coefficient, the soil strength and the rainfall intensity impacting on the bank slope stability. The influence of reservoir water level change was emphasis analyzed. Water level rise can improve the bank stability, and water table drop down can reduce stability of the slope. This phenomenon is caused by the change of dynamic water pressure and the slope seepage field changes in the slope body.(2) Established the saturated-unsaturated finite element calculation model of Majiagou landslide in the Three Gorges, compared the different influence factors about the different soil water level fluctuation rate, permeability coefficient, the soil strength and the influence of rainfall intensity on the landslide stability. The landslide is osmotic pressure type, the minimum safety factor appears when water levels fall.(3) Introduced the application of fiber optic monitoring technology in the slope monitoring. According to the monitoring data of Majiagou landslide draw a landslide sliding surface. Although the accuracy of the numerical simulation is affected by many factors, but the software simulation results and the actual monitoring results agreement is still relatively good.