Study On The Mechanical Properties Of Sand Loam In Juancheng Section Of Yellow River Embankment

Yellow River embankment is an important component of the flood control project in the downstream of the Yellow River in China.Due to the influence of rainfall and compaction,the strength of embankment soil is often restricted.Sandy loam as the main embankment filling material,the influence of moisture content and dry density on the shear strength of sandy loam is studied to ensure that its mechanical properties meet the requirements of embankment stability.In this paper,the sandy loam of the embankment in juancheng county of shandong is studied.Through the indoor geotechnical test,to study the influence of moisture content and dry density on the shear strength indices of sandy loam,statistically derive quantitative relationship,and study on the influence of moisture content and dry density on the stability of the Yellow River embankment with FLAC^3D.This paper focusing on two research directions spreads as follows:（1）Through conventional soil tests on soil samples,study the physical characteristics of soil.According to the obtained soil physical properties indices,the engineering properties of filling soil are estimated roughly.Test results show that:Particles account for 81.2%,the soil is denominated of heavy silty sandy loam according to triangular coordinates.（2）Through consolidated undrained multi-stage triaxial tests on undisturbed soil samples under different moisture contents,obtain a fitting relationship between moisture content and soil shear strength indices.Test results show that:The relationship between moisture content and shear strength indices is three-function relationship,the internal cohesion increases first and then decreases with the increase of moisture content,when the optimal moisture content,the internal cohesion value is the largest,the internal friction angle decreases with the increase of moisture content.（3）Through consolidated undrained multi-stage triaxial tests,to study the change rule of shear strength indices with dry density of undisturbed sandy loam.Test results show that:Both the internal cohesion and the internal friction angle increase with the increase of the dry density,and it’s linearly increasing,however the effect of dry density on the internal friction angle is not obvious.（4）Quantitative relation based on moisture content,dry density with shear strength indices,with FLAC^3D to analyze stability of Yellow River embankments under different test conditions.Analysis results show that:As the moisture content increases,the safety factor increases first and then decreases,the safety factor increases with the increase of dry density.Therefore,when filling the embankment,the moisture content of the filling material should be controlled near the optimal moisture content.