Study On Rock And Soil Mechanics Parameters Partition Of Landslides In The Three Gorges Reservoir

The Three Gorges Reservoir Region is one of the most serious geological disastersregions in China. Causes of landslides are varied, but the main reason is determined bythe topography, geology and rainfall. The value of the physical parameters of rock andsoil, especially shear strength parameters, has plagued engineers for long time. Based onreferences, this paper analysis the rock and soil physical parameters of26collectedlandslides and get some meaningful conclusions.1) The reasons for the formation of the Three Gorges Reservoir Region landslide is the result of many factors working together, and this paper detailed the factors leading to the formation of landslides in the Three Gorges Reservoir Region, which including:1, topography;2, hydrology and meteorology;3, groundwater types and recharge, runoff, drainage characteristics;4, the geotechnical characteristics;5, tectonic activity and earthquakes;6, human engineering economic activities.2) Based on the discreteness and weak correlation of the physical properties of rocks and soils, this article does not using principal component analysis(PCA).3) Function relation analysis method and linear regression analysis is used in this paper which are intuitive and simple.4) In this paper, silty clay soil using a linear regression method to obtain largediscrete soil parameters, only a few groups of related better.5) Associated rocky soil better than paper of shale rock using a linear correlationanalysis to obtain the parameters of discrete small rocks, most of the correlationcoefficient greater than0.5.6)Three Gorges reservoir lithology can be divided into four regions: I clay,sandstone seam; Ⅱ marl, sand, shale; Ⅲ limestone, dolomite with shale,④igneous and metamorphic rocks. Three Gorges reservoir lithology distribution diagramwith26landslides description of the geological survey report lithology good agreement,indicating that the Three Gorges reservoir lithology distribution diagram has a certainaccuracy.7)The average of the different lithologies partition statistics Landslide shearstrength under different experimental conditions, the statistics illustrate the differentlithologies slip soil shear strength significantly different. In addition to residualsaturation cut, but in a natural fast scissors, cut the natural residual saturation of fast shear test method in large shear test, Ⅲ limestone, dolomite folder inside sliding soilfriction angle than other shale rock sliding partitions internal friction angle of the soilwith large. The cohesion of the law is less clear.8)By I sand and mudstone seam zone Ⅱ marl and sand, shale zone landslidelandslide slip zone soil and soil shear strength comparison found that the shear strengthof the soil in a natural landslide fast shear, natural residual scissors, scissors fastsaturation, saturation residual shear, large shear strength parameters than sliding testwas high with soil strength parameters, and even a difference of nearly two-fold insome cases. This illustrates the landslide soil and sliding soil obvious differences in theshear capacity in the survey process should pay attention to distinguish between soil andlandslide sliding soil, prevent soil shear strength selected landslide slope stabilityparameters safety factor analysis, overestimated landslides, causing a safety hazard.