Study On Stability Of Geogrid Reinforced Coarse Grained Soils Embankment Slope

Under the influence of various factors,the fill embankment can easily cause deformation and instability of the embankment slope.The geogrid has good engineering characteristics,can effectively improve the deformation characteristics of the embankment,and reduce the horizontal displacement of the slope.Based on a reinforced embankment project in the southwest mountainous area,this paper takes geogrid and uniform coarse-grained soil with different particle size ranges as the research object,and studies the slope stability through laboratory test and numerical simulation.The main work and research results as follows:(1)Through the test of basic physical and mechanical properties,it is found that the gradation of the three groups of coarse-grained soil is not good,but the particle distribution is relatively uniform;the larger the average particle size of the coarse-grained soil,the lower the optimal moisture content,and the average granule The smaller the diameter,the higher the optimum moisture content.(2)Through the indoor pull-out test of geogrid and coarse-grained soil filler,the effects of normal stress,particle size and drawing rate on the interface characteristics were analyzed.It is found that the maximum drawing force of the geogrid increases with the increase of the particle size and the drawing rate of the filler;the increase of the particle size of the filler significantly increases the interfacial friction parameter like cohesion,and the friction angle is similar.The effect is not obvious;the increase of the drawing rate makes the cohesive force almost linearly increase,and the friction angle does not change significantly.(3)Applying the interface friction parameters obtained from the drawing test to the material parameters in the numerical model,and simulating the geogrid reinforced coarse-grain soil embankment project by FLAC~3DD software,considering the type of filler,the modulus of the grid,the location of the reinforcement,and the addition.The influence of the five factors of the number of ribs and the spacing of the reinforcement on the stability of the slope.Through numerical calculations,it is found that several factors such as the type of filler,the number of reinforced layers and the spacing of the reinforcement have a relatively large influence on the stability of the slope.The increase of the particle size of the embankment increases the safety factor of the slope significantly.The increase of the number of layers makes the safety factor of the slope gradually increase;the smaller the reinforcement spacing is,the larger the safety factor of the slope is,but when the reinforcement spacing is reduced to a certain value,the increase of the safety factor is obviously smaller.The influence of the grid modulus and the reinforced position on the slope stability is relatively small.When the grid modulus increases to a certain value,the safety factor no longer increases;when the reinforced position is in the vicinity of the slope,the safety factor is a very small increase.The research results of the thesis can provide theoretical basis for the design and construction of similar reinforced soil slope structures,and have certain application value.There are 48 graphs,27 tables and 67 reference in this paper.