Study On Bearing Characteristics And Additional Stress Diffusion Mechanism Of Geogrid Reinforced Earth Retaining Wall

Reinforced earth retaining wall has good engineering economy,construction convenience,seismic performance and the ability to adapt to soft soil foundation.It has become a common way of filling embankment reinforcement in engineering.Many scholars have studied the factors affecting the deformation of reinforced earth retaining wall.At present,there are few studies on the influence of the slope and reinforcement location of reinforced soil retaining wall on the bearing characteristics of reinforced soil retaining wall,and the research conclusions rarely analyze the distribution law of additional stress in reinforced soil retaining wall from the perspective of additional stress diffusion mechanism.Based on the model tests of five working conditions,this paper explores the effects of the slope of the retaining wall,the number of reinforced layers and the layout position of reinforcement materials on the bearing characteristics of reinforced soil retaining wall,and analyzes the distribution law of additional stress in reinforced soil retaining wall in detail.The boundary equation of additional stress diffusion is established,and then the calculation formula of additional stress in the diffusion range of parabolic cone under uniformly distributed load is derived.The main research contents and results are as follows:(1)Under the same load,increasing the number of reinforced layers and reducing the slope of the retaining wall can limit the horizontal displacement of the wall and the vertical settlement of the wall top,and improve the ultimate bearing capacity and overall stability of the retaining wall.The horizontal displacement of the wall increases with the increase of the height of the wall.The layout position of reinforcement has a great impact on the deformation and bearing capacity of the retaining wall.Compared with the middle and lower part of the retaining wall,the layout of reinforcement in the middle and upper part of the retaining wall can better limit the overall deformation of the retaining wall and improve the bearing capacity.(2)By analyzing the distribution law of additional stress in the retaining wall,it is found that the increase of vertical uniformly distributed load will disturb the sand body,resulting in the release of stress in the sand body.At the same time,the diffusion angle of additional stress also changes with the change of load,so that the distribution law of additional stress is not completely that the additional stress in the upper part of the retaining wall is greater than that in the lower part.(3)According to the results of PFC2 D simulation,it is found that the diffusion angle of additional stress transmission increases with the increase of load,and the diffusion angle of additional stress also changes continuously in the process of transmission.With the increase of transmission depth,the diffusion angle decreases continuously,and the diffusion range of additional stress is roughly in the shape of parabola cone.(4)Four factors that may affect the diffusion range of additional stress are analyzed by PFC2 D simulation.It is determined that the load and friction coefficient are the main factors affecting the diffusion range of additional stress.According to the shape of the diffusion boundary of additional stress,the boundary equation including the main influencing factors is established,and the calculation formula of additional stress under uniformly distributed load is deduced according to the boundary conditions.