Numerical Study On Stability And Failure Pattern Of Loose Deposits Slope Along Reservoir Bank

The stability problem of reservoir bank loose slope is very important for the coastalengineering (such as port, wharf engineering, etc). Based on the field investigation ofloose deposit slope in Yingxiu to Wenchuan section along Minjiang river，the researchon stability and failure pattern of loose deposit slope in reservoir bank are carried outusing the numerical simulation method, and simplified calculation methods of slopestability, landslide pushing force and sliding distance of safety design of slope aresuggested. The specific content and conclusion are included as follows:(1)According to the field investigation of loose deposit slope in Yingxiu toWenchuan section along Minjiang river. The laser range finder, geological compass andother tools are used to measure and analyze the structural form, rock and natural reposeangle of the slope, which provide basic data for numerical model of slope. Combinedwith the method of traditional limiting equilibrium and finite element strength reduction,the research comparatively analyzes the mechanical mechanism of material parametersand structure of reservoir bank slope, which are the two main influence factors for theslope stability, and the influence of density and water ratio on slope stability are alsoanalyzed by numerical simulation methods.(2)The influence factors of the failure mode for the deeply buried bedrock slopeare analyzed deeply. The calculation results indicate that the parameters and slopestructure have great influence on the form and depth of sliding position. The geometricshape, interface parameters and angle of the bedrock interface are the main factorswhich control the failure mode of the shallow buried bedrock slope. And some criticalconditions about the slope failure happening in the internal circular or along the bedrocksliding are summarized.(3)Based on saturated-unsaturated soil seepage theory, transient seepage field ofslope is deeply analyzed under the condition of drawdown of water level and rainfallrespectively. The influence of excess pore water pressure on slope stability is discussedin detail, and the influence of intensity and duration of rainfall to slope stability throughdifferent design scheme are analyzed.(4)Based on a large amount of numerical simulation, simplified calculationmethods referred to slope stability, landslide pushing force and sliding safety distance of slope are put forward, which provide basis reference for the design and assessment ofactual engineering.