A Simplified Model Of Reinforced Subgrade And Analysis Of The Interaction Characteristics Of Reinforcement And Soil

In recent years,geogrid reinforcement,as an effective subgrade reinforcement method,has been widely used in highway construction in soft clay area.The research on the interaction mechanism of reinforced soil is still lagging behind the practical application of the engineering.Therefore,it is very necessary to analyze the theory of reinforced subgrade.The theoretical model and the numerical simulation of reinforced subgrade are studied in this paper.1.Based on the analysis of the single-layer reinforced subgrade settlement model proposed by Yin,a simplified settlement model of single layer reinforced subgrade was established.The following two simplifications were made:(1)Considering that the inclination angle of the reinforced material in the lateral(horizontal direction)of the subgrade is small,the angle change at both ends of the micro-segment unit of the reinforced material was ignored.(2)The lengthening of the reinforced material caused by the lateral displacement of the soil was only taken into account,while the length of the reinforcement caused by the settlement of the soil was ignored.Its rationality was verified by an example.2.A numerical model of subgrade reinforced by single layer geogrid under the condition of step loading during the construction and the working state was established by using ANSYS.The settlement and deformation rules of the roadbed and soft soil foundation and the tension change of geogrid were studied respectively.The results show that reinforcement can effectively reduce the settlement and deformation of subgrade and soft soil foundation,and the tensile force of geogrid increases first and then decreases along the direction far away from the center of the roadbed.3.Based on the finite element numerical model of the subgrade reinforced by single layer geogrid,a finite element numerical model of the subgrade reinforced by multi-layer geogrids was established.The influence of factors such as number of geogrid,position of geogrid,modulus of geogrid,nature of roadbed fill and elastic modulus of foundation soil on the settlement and deformation of subgrade and soft soil foundation and the tension change ofgeogrid were studied.The results can provide some references for the subgrade reforced by geotextile in practical engineering.