Study On Uneven Settlement Of Super High Fill Of Coarse Grained Soil On Slope Foundation And Its Influence On Mechanical Characteristics Of Pile Foundation

Coarse grained soil is the first choice for filling around pile foundation of high-speed railway station and airport in mountainous area.However,due to the long period of self weight consolidation of coarse-grained soil,long-term and slow post construction settlement deformation will occur,especially for mountain slope foundation,which will cause long-term negative friction resistance and shear stress on the pile body in high fill foundation,and affect the safety of pile foundation structureBased on the super-high coarse-grained soil filling project of a high-speed railway station,this paper selects a pile foundation condition as the research object,carries out the research on the uneven settlement of the super-high coarse-grained soil fill,so as to clarify the internal mechanism of the influence of the pile foundation stress characteristics.In addition,the bottom of the filling soil is the original landform,and the original topography has a certain angle,which is called the slope foundation angle in this paper.The main research work is as followsBased on the engineering background,the two-dimensional particle flow method is used to establish the macro calculation model of loose coarse-grained soil and pile foundation of slope foundation for numerical simulation.The basic physical and mechanical parameters are selected from previous experienceSecondly,taking the numerical analysis model as the main body,from the difference of relative settlement of coarse-grained soil on both sides of pile foundation under different deformation,time effect of settlement of coarse-grained soil due to self weight consolidation and stress characteristics of pile foundation,relative settlement of coarse-grained soil and negative friction resistance of pile foundation.Qualitative and quantitative analysis is carried out from the angle of the change law between the relative displacement of coarse-grained soil and the lateral pressure of pile foundation.Finally,through theoretical calculation,the difference between the horizontal displacement of pile foundation and the measured data is within the allowable error range,so the conclusion of this paper is effective and reliable.Therefore,this study has very important engineering guiding significance.