Experimental Study On Mechanical Properties And Structural Properties Of Silicon Powder Improving Loess

As a special soil,loess is widely distributed in the central and western regions of China.In the study of soil quality improvement in loess,there have been a lot of improvement methods and methods,and there are rich research results.in this paper,the soil quality of the loess area in Xi'an is improved by the combination of silicon powder materials and cement.Through an indoor experiment,To study the changes of mechanical properties and structural changes of modified loess.Through the integration of the experimental results,the relationship between structural stress and strain is obtained,and then structural parameters can be introduced into Duncan-Chang model for correction.The following achievements have been made in this paper:(1)The shear stress-shear displacement relation of loess is obtained by direct shear tests with different mixing ratios and under different conditions,and the relation between shear stress and different variables is analyzed.According to the experimental results,the relationship between shear strength index and the mixing ratio and friction ratio was obtained.The cohesion of loess increases with the increase of mixing ratio,while the internal friction angle increases slowly and tends to band distribution.The higher the water content,the smaller the cohesion of the Improved Loess and the smaller the internal friction angle.(2)The stress and strain relationship of modified loess is studied on the basis of conventional triaxial drainage test,and the variation law of stress and strain relation of modified loess is studied.According to the results,the change trend of the damage intensity and the mixing ratio and the friction ratio was obtained.The structural parameters of modified loess are established by conventional triaxial test results.The influence of different mixing ratio,different containment pressure and different concrete on its structural parameters was analyzed.(3)A modified permeability coefficient of loess is obtained from the waterhead infiltration test,which is used as a reference for the test.(4)By introducing the structural parameters obtained from conventional triaxial tests into the stress strain relationship of improved loess,the structural stress strain relationship curve of improved loess is obtained,and then according to Duncan-Chang structural modification of Duncan-Chang model parameters is obtained by fitting the double curve of the model.