Stability Analysis Of Loess Slope Improved By Cement And Silica Powder

Loess is collapsible,so it cannot be directly used as engineering soil,and must be technically treated to meet the actual needs of different projects.The strength of the improved loess is closely related to the safety and stability of slopes and highway embankments in the loess area.It is a common method to improve it by adding curing materials,and many curing agent products have been applied in actual engineering construction.At this stage,most of the research on soil curing agents in China has focused on inorganic materials,and great progress has been made.In this paper,cement and silicon micropowder are used as solidification materials to improve the loess.The strength characteristics of the improved soil are analyzed through experiments,and the deformation and sensitivity of the improved soil slope are studied with the finite element analysis software ABAQUS.The main contents are:First,through the compaction test and shear strength test of cement and silicon micropowder solidified loess,the influence rules and reasons of cement incorporation ratio,silicon micropowder incorporation ratio and age on the shear strength index of cement silicon micropowder modified loess were studied..The test results show that the addition of silicon powder to cement soil can effectively improve the shear strength of cement soil;the effect of adding two materials at the same time is better than the effect of adding one material alone to improve the treatment of loess;under the condition of 3% of cement and 10%of silica fume,the strength of improved soil is improved most obviously;the longer the curing age,the higher the shear strength of the improved loess.Therefore,if conditions permit,the curing time of the improved soil should be extended as much as possible.Then,according to the test data,the elastic modulus,Poisson's ratio,reinforcement thickness,soil gravity and slope angle are taken into account as parameters,and the finite element software ABAQUS is combined with the strength reduction method to calculate the corresponding cloud chart and safety coefficient of the improved loess slope deformation under different physical and Mechanical parameters.The results show that Poisson's ratio and modulus ofelasticity have little influence on the deformation and safety factor of the slope;when the angle of the slope and the gravity of the soil increase,the values of the deformation in all directions of the slope increase.Through the simulation analysis of the slope sensitivity,it is found that the slope angle and the soil gravity are inversely proportional to the safety factor of the slope;the sensitivity is arranged from high to low as: the soil gravity,the slope angle,the elastic modulus and the Poisson's ratio.The study conclusion has certain reference value for the application of cement silica micro powder to solidify loess,which can be used for the design of the follow-up slope engineering,the prevention and treatment of slope instability.