Analysis Of Dynamic Shear Modulus And Damping Ratio For West Sichuan Unsaturated Mixed Soil

In the west of Sichuan,there is a kind of special slope collapse mixed soil,which is caused by the earthquake load.According to the typical mountain area of Western Sichuan river valley and valley slopes of the colluvial mixed soil,the prominent features of coarse particle content difference,through the large three triaxial tests.The research in small strain range,under cyclic loading,the consolidation of coarse aggregate content,confining pressure on the dynamic deformation characteristics?dynamic shear modulus,influence of damping ratio?.Through the experimental study and theoretical analysis,the main results and conclusions are as follows:First of all,the physical properties of the collapsed slope mixed soil with three different slopes of the same landslide are studied,including the identification of mineral composition,natural water content,natural density,soil particle gradation test and so on.The identification of mineral composition showed primary mineral composition content of three kinds of soil are similar to quartz and plagioclase content of hydrophilic is highest,and strong hydrophilic clay components?montmorillonite?minority,and therefore can be considered the same type of soil,with similar properties.The results showed that there were significant differences in the content of coarse particles of three kinds of soil more than 5mm.Secondly,the effect of coarse particle content and confining pressure on the dynamic characteristics of the collapse and slope soil in the west of Sichuan was studied by the large scale dynamic three axial test.The Mathematica data processing software was used to fit the experimental data according to the Hardin-Drnevich hyperbolic model,and the curves of G_d/G_max??_d and ???_d were obtained.According to the fitting curve theory,the influence of coarse particle content and confining pressure on the dynamic shear modulus and damping ratio of the mixed soil was studied.It is found that the dynamic shear modulus and damping ratio increase with the increase of coarse particle content and confining pressure.In addition,collect test data painted brake shear modulus Gd and damping ratio relationship between lambda graph with the content of coarse particles,found in colluvial mixed soil in the range of content of coarse particles under different soil samples the maximum dynamic shear modulus and damping ratio of the maximum growth trend is different,the overall growth trend of the two characteristics from low to high to reduce.Finally,the dynamic shear modulus ratio and damping ratio function of each soil sample are obtained by using the dynamic three axial test data of the slope of Chuanxi.