Study On Influence Of Cement Modified Soil On Stability Of Filled High Slope

When large-scale construction is carried out in the high and low undulating western mountainous areas,many artificial high-filled slope problems will inevitably arise,which plays a vital role in engineering safety.The choice of fillers for high-filled slopes is particularly important.How to choose economical fillers in areas where good fillers are lacking to ensure slope stability has always been a problem in high-fill slopes.Cement improved soil has achieved good results in recent years in the water conservancy,transportation,construction and other industries.Therefore,as a cheap and improved material,cement improved soil has received more and more attention.In this paper,combined with the case of a high-fill slope project in Yulin,northern Shaanxi,the undisturbed soil,remolded soil and cement-modified soil in the site were taken as research objects,and the compaction test,shear test and consolidation test were carried out on cement-modified soil with different mix ratios.To study the compaction characteristics,strength and deformation characteristics of remolded soil under different cement contents,and analyze the variation of strength and deformation of different water content and different compaction degree under different cement mix ratios.Then the gray correlation analysis method is used to analyze the factors affecting the stability of backfill high slope.Finally,the numerical simulation is used to investigate the stability of high fill slope under different slopes and different slope heights.The research results are as follows.(1)The results of the compaction test are related to factors such as soil sample preparation method,cement mix ratio,and compaction work.(2)When the water content is constant,the cohesive force of cement-modified soil increases with the increase of compaction degree;when the compactness is constant,the cohesive force of cement-modified soil increases first and then decreases with the increase of water content;However,the internal friction angle is less affected by changes in compactness and moisture content.(3)The gray correlation analysis method is used to analyze the stability of the high slope of the fill.The sensitivity factors are the internal friction angle,cohesion,gravity,slope rate and slope height.(4)The finite element analysis shows that with the increase of the cement mixture ratio,the safety factor increases gradually,and the horizontal displacement of the slope foot gradually decreases.When the slope height is 40 m and the grading slope rate is 1:1.2,when the cement mix ratio is 8%,the stability of the slope can be satisfied.(5)When the grading slope rate is less than 1:1.4,6% cement modified soil can be used as the filler;when the grading slope rate is greater than 1:1.4,8% cement modified soil should be used as the filler.