Multi-step Reinforced Soil Retaining Wall Deformation And Stability Research And Analysis

With the development of civil engineering and geotechnical engineering,the application of geogrid into multi-step retaining wall becomes crucial and practical.However,the research on the reinforcement mechanism and theory cannot satisfy the construction demand,which means the existing theoretic basis is insufficient to support the practical construction.Consequently,the research on the application of geogrid into Multi-step retaining wall needs to be broadened.This research aims to study the stress,strain and stability of the three-step reinforced soil retaining wall by using the finite element method.In specific,four main research contents and results are epitomized below.(1)The development of horizontal displacement,vertical settlement and mechanical characteristics of the three-step reinforced soil retaining wall can be observed in the site experiments.It is found that when the height of the retaining wall increases,its horizontal displacement and vertical settlement rise as well.Furthermore,the reinforcement and L-type foundation can restrain the soil movement.In addition,the vertical soil stress redistribution would happen on both sides of the retaining wall due to its reinforcement and steps.(2)In order to analyze the stress and strain in the three-step reinforced soil retaining wall,the Mohr-coulomb elastic-plastic model is applied to the soil,moreover,Plaxis(a finite element software)is used for establishing the model.Meanwhile,the strength reduction method is also applied to simulate and calculate the potential slip surface and safety factor.According to the results,it can be found that the vertical soil pressure on the reinforcement bottom grows along with the increase of wall back soil stress.Furthermore,the maximum horizontal displacement occurs on the second step reinforced soil retaining wall,meanwhile,the horizontal displacement of second and third step reinforced soil retaining wall are larger than the maximum horizontal displacement of the first step reinforcement soil retaining wall.It can be obtained that the first step reinforcement soil retaining wall has the minimum horizontal displacement,moreover,the sliding surface of the reinforced soil usually located at the slope toe.In addition,the retaining wall can be regarded as a whole,the sliding surface follows the Rankine's earth pressure theory.(3)After conducting numerical simulation analysis to the force and deformation of the three-step reinforced soil retaining wall,the numerical simulation analysis results are compared with the site measurement results.It can be found that though both the simulation analysis results and site measurement results are all discrete,they have the similar variation tendency.Moreover,the measurement data are smaller than the theoretical data,which indicates that the theoretical calculation is more conservative.(4)When analyzing how the backfill properties,geogrid reinforcement spacing,reinforcement tensile strength,the strength of foundation and other parameters influence the horizontal displacement and stability of the reinforced soil retaining wall,it can be obtained that in the design and construction stages,it is recommended to adopt the wall materials with some specific features,such as geogrid with good axial tensile stiffness;backfill with proper elastic modulus,cohesion and internal friction angle and relative dense reinforcement spacing.Overall,these research findings have great reference value for the multi-step retaining wall design.