Study On Performance Of Soil And Optimizing The Structure Of High Embankment Reinforced By New Geocell

The new geocell is a three-dimensional reinforced material,which has the characteristics of uniform stability,high node strength,large modulus of elasticity,high tensile strength,corrosion resistance and aging resistance.Its application prospect is expansive.High fill embankment has the engineering characteristics of high fill height,wide floor area and large fill volume.Considering the super reinforced performance of the new geocell and the interaction between the embankment filling and geocell,laying geocell in the high fill embankment can improve the strength of the soil and the stability of the embankment.Therefore,the embankment slope is optimized and the occupied area and filling volume are reduced.However,the existing theoretical research of reinforced soil is not perfect,the research of reinforcement mechanism and design theory lags behind the engineering practice,and the application of new geocell reinforced embankment is lack of examples,which greatly limits the application and promotion of new geocell.In view of the above problems,this dissertation studies the interface resistance characteristics,mechanical properties and structural optimization of Geocell Reinforced High Fill Embankment Based on the background of a highway high fill embankment project by the combination of laboratory test and numerical analysis.Firstly,the reinforcement mechanism of the new geocell is studied from the application of the geocell.Secondly,the influence of the degree of compaction and moisture content of cohesive soil on the interface resistance of reinforced soil is discussed through the pull-out test,and the influence of the degree of compaction,the number of reinforcement layers and moisture content on the compressive strength of reinforced soil is analyzed through the unconfined compressive strength test.Finally,according to the test results and engineering examples,the ABAQUS software is used to establish a numerical analysis model to optimize the structure of the new geocell reinforced high fill embankment,and the optimization method of the reinforced high fill embankment structure is proposed.Finally,based on the proposed structure optimization method,the reinforced structure design is carried out and compared with the original design scheme.Based on the above research,the main conclusions are as follows:(1)The degree of compaction and moisture content of soil have a great influence on the coefficient of interface resistance.With the increase of compactness or the decrease of water content,the interface resistance coefficient increases.(2)The higher the degree of compaction,the more layers of reinforcement and the lower the water content,the greater the compressive strength of the new geocell reinforced soil.With the increase of the number of reinforcement layers,the degree of compaction will decrease the increase of the compressive strength of the reinforced soil.When the number of reinforcement layers is more,the influence of compactness on compressive strength is less.When the number of reinforcement layers is 2,the increase of compressive strength is the largest.When the degree of compaction is 94%,and the moisture content is reduced from 19% to 11%,the compressive strength is increasing,but the increase is decreasing 66.8%,60.3%,31.5%.(3)The optimization results of the embankment structure show that the reinforcement effect is the best when the grid size of the new geocell is 20 cm × 20 cm and the height is 10cm;the reinforcement spacing of the geocell is 2m,which is the best choice;the slope rate of the embankment is 1:1 and the slope grade is 3.According to the results of optimization,a new optimization design method of geocell reinforced embankment structure is proposed.(4)The numerical simulation analysis method is used to compare the mechanical properties of the embankment before and after the reinforcement.The results show that the application of the new geocell can effectively restrain the settlement of the high fill embankment and enhance the stability of the embankment.And the distribution range of tensile stress and potential sliding failure area of reinforced embankment are greatly reduced.