Slope Seepage And Failure Mechanism Of Landslide Under Rainfall

On account of the complicated geological conditions of the topography and geological conditions in our country, landslides occur frequently. Rainfall, especially the intense, long endurance storm and extraordinary storm are the main factors that affect the slope stability. According to the statistics, more than90%of the landslides are related to rainfall. Therefore, the research of slope stability under the condition of rainfall is of great importance to the slope failure mechanism and governance.Based on the research project of Bijie to Weining highway K86+680-K86+980high slope, this paper reached the law of soil strength reduction by establishing a unsaturated soil model. On the basis of ABAQUS finite element model, this paper analyses the seepage inside the slope, the influence factors of slope stability and the slope instability mechanism. The main results of this paper are as follows:1. Establish the soil strength reduction model, the cohesion c and friction angle φ are seen as composed of two parts, one part has nothing to do with the water content, the other part does. Beside, this model is compared with the traditional unsaturated soil strength theory in order to prove its correctness.2. Analyze the seepage law under the condition of rainfall. The results showed that: under the specific rainfall duration condition, the pore pressure increases nonlinearly with rainfall intensity, the flow velocity increases nearly linear growth with rainfall intensity; under the specific rainfall intensity condition, the pore pressure and flow velocity increase nearly linear growth with rainfall duration.3. Analyze the mechanism of slope failure respectively from three different angles: geotechnical properties, mechanical aspects, and rainfall.4. Determine the main factors affecting slope stability by studying the cohesion, friction angle, deformation modulus, Poisson’s ratio, rainfall intensity, rainfall duration and seepage coefficient.