Study On Mechanical Behavior And Calculation Methods Of Pile-supported Beam With Retaining Wall On Large-area And High-fill Embankment On Slope Foundation

The large-area high-fill embankment project formed on the slope foundation usually uses the pile-supported beam with retaining wall structure to support the block,which can not only control the overall deformation of the filling area,but also improve the slope stability and avoid the occurrence of landslides.In order to deeply analyse the stress characteristics of such pile foundation girder retaining wall structure,especially the method of determining the lateral earth pressure at the back of the wall,this paper relies on the engineering practice of the Pingnan station of Quning Railway,using theoretical analysis,numerical simulation and on-site monitoring methods The stress mechanism and calculation method for pile-supported beam with retaining wall acting on large-area high-filling works on the slope foundation were studied.The main findings are as follows:(1)Through FLAC3D software numerical simulation,the action mechanism of the pile-supported beam with retaining wall is analyzed,the force transfer mechanism of the pile-supported beam with retaining wall,and the control principle of the slope deformation and stability are given.(2)Based on the stress mechanism of the retaining structure of the pile-supported beam with retaining wall,the "overboard" failure mode of the high fill soil over the slope will occur when the backfill soil is in the limit equilibrium.Using the limit equilibrium method combined with the principle of extreme value,the formula for calculating the active earth pressure behind the retaining wall was deduced.The influences of the friction angles in the fill soil,the fill slope slope,the natural slope angle,and the wall dorsal inclination angle on the instability mode and the earth pressure are given.(3)Based on the force transfer mechanism of the pile-supported beam with retaining wall and the earth pressure analysis method of the limit state behind the wall,the force model of the joist,the calculation formula of the bending moment and the shear force of the pile structure are further given,and the pile foundation is formed.calculation and analysis methods for pile-supported beam with gravity retaining wall structures.(4)According to the actual conditions of the typical work stations in Pingnan Station of Quning Railway,the numerical simulation and field measurement results of the force acting on the retaining wall of the pile foundation are compared and analyzed.The results of theoretical analysis and numerical simulation are also analyzed.The correlation analysis method is further illustrated.the rationality.(5)Numerical simulation method is used to further discuss the influence of the main factors such as slope foundation properties,fill height,pile stiffness,and internal friction angle of fill on the stress and deformation of the retaining wall of the pile foundation.This paper relies on the large-area high-fill embankment of Pingnan Station slope in Suining Railway.The research results of the accepting mechanism and calculation method for the retaining wall of the pile foundation support beam can provide guidance and reference for similar practical projects,and has important theoretical and practical significance.