Study On Interaction Between Passive Piles And Soils Under Soft Soil Foundation Under The Stowage

In order to meet the needs of travel and urban development,land reclamation projects near existing railway bridges have emerged in recent years.This kind of engineering will face a hot and difficult problem,that is,the interaction between the pile and soil of the passive pile.Based on the research background of"the safety impact of reclamation project of Kemen port on Nanqiwei large railway bridge",the paper uses the finite difference software FLAC^3D to conduct three-dimensional numerical simulation analysis on the passive pile under loading conditions.The main work and achievements are as follows:?1?The deformation,internal force and soil displacement field of the pile foundation under four piers of Nanqiwei bridge are analyzed in detail.According to the working conditions and relevant parameters given by the relevant survey and design data,the finite difference software FLAC³DD is used to establish the 3D numerical model.The vertical and horizontal displacement of the soil,the horizontal displacement of the pile,the bending moment of the pile and the response of the axial force of the pile under pile load are studied.Through calculation,it is found that the horizontal displacement of pile top of 16#,60#,115#and 137#piers is113mm,85mm,98mm and 10mm respectively,which exceeds the limit of horizontal displacement of railway bridge pile foundation of 8mm.?2?The deformation and internal force response of adjacent bridge piles under load conditions are analyzed.The effects of the pile-up distance,stacking height,pile load weight,soft soil elastic modulus,soft soil poisson's ratio and pile body elastic modulus and the length of the pile towards passive pile character are mainly investigated,and universal law is obtained.It is found that the lateral displacement of pile increases with the increase of pile height,pile load weight and soft soil poisson's ratio and it decreases with the increase of loading distance,elastic modulus of soft soil and pile length.The conclusion is basically consistent with the results of previous numerical simulation analysis.?3?Theoretical calculation method and numerical simulation method based on elastic foundation beam method are respectively applied to calculate representative pier,and the results are compared,and it is found that the two results are generally close.?4?According to the deformation characteristics of the pile foundation,the measures to control the deformation of the pile foundation are proposed.The soft soil foundation can be treated by the drainage sand pile method and the preloading method,or the horizontal deformation can be controlled by the method of setting the isolation pile.In the case of requirements,the safety requirements of railway bridge pile foundation deformation can also be achieved by changing the pile load weight or the pile spacing.