Design Of Shallow Slope And Reinforcement Of Slope With Geosynthetic-encased Stone Column

Recently,slope stability analysis and slope reinforcement measures have been focused mainly on the deep and global stability.The study on the shallow stability of slope,however,is relative few.In this thesis the shallow stability of slope considering different design parameters is presented.Moreover,the geosynthetics-encased stone column?GESC?,which are widely applied in reinforcing the foundation of embankment,was used to stabilize slope.The validation and mechanism of GESC were investigated on the basis of a series of lab tests and numerical analysis.The main research contents and conclusions are as follows:Firstly,based on the finite difference strength reduction for slope,comprehensive analysis considering the effect of width and cohesion of strengthened zone,depth of strengthened zone below slope toe,and geometry of slope on stability and failure surfaces are presented here when slope possess the same foundation materials or firm rock foundation,respectively.The results showed that for slope with the same foundation materials safety and different width of strengthened zone,coefficients of slope tend to decrease and then increase with the increment of cohesion of strengthened zone,and keep stable later once cohesions reached some critical value.With the increase of soil cohesion in strengthened zone shear strength of strengthened zone has much stronger than non-strengthened zone's,the failure surface of slope moved towards non-strengthened and foundation,and passed outside the strengthened zone lastly,furthermore,increasing the depth of strengthened zone below toe can enhance the stability to some extent.For slope with firm rock foundation,safety coefficient decreases and then increases linearly with the increase of soil cohesion of strengthened zone,moreover,safety coefficient would be about0.5¹ times than slope with the same foundation materials.Keeping the same width of strengthened zone,with the increase of cohesion of soil in strengthened zone,therefore,the slope is more stable.Secondly,geosynthetics-encased stone column was applied in reinforcing the shallow slope,and then 13 groups of geotextile reinforced gravel pile reinforced slope were studied with the model of reduced scales under consideration of position,length,configuration of pile and types of geotextiles.The optimum slope pile,?x/H?_opt=0.8,and the optimal pile length,?L/H?_opt=0.75,were obtained.The ultimate bearing capacity of slope increases with the increase of strength of geotextiles.At the same time the inclination angle of piles tended to be greater.Generally,the presence of geosynthetic-encased stone column can effectively prevent horizontal displacement of the slope,and sliding surface of lope is circular-arc.Finally,base on platform of software ABAQUS,this paper is aimed to analysis the slope stability,the distribution of the force of the pile and the soil mass,and the deformation of the pile body.