Study On Design And Structural Behavior Of Reinforced Earth Retaining Wall Of Stepped Gabion Wall

At present,scholars at home and abroad have studied the stress and deformation characteristics of gabion reinforced soil retaining wall,but there are few studies on the structural deformation characteristics of stepped gabion geogrid reinforced soil retaining wall,and the structural behavior of the corner part of stepped gabion reinforced soil retaining wall is more urgent to be studied.Based on the above considerations,on the basis of relevant theoretical research,this thesis is based on the stepped gabion wall reinforced earth retaining wall project of Yichang North Station EMU depot in Wuhan-Yichang section of Shanghai-ChongqingChengdu high-speed railway.The method of combining theoretical analysis,laboratory test and numerical simulation is used to analyze and study the deformation behavior of the structure during the construction process and the stress-strain characteristics of the straight section and corner of the stepped gabion wall reinforced earth retaining wall under many influencing factors.The main research contents and conclusions are as follows :(1)The stepped gabion wall reinforced earth retaining wall is introduced.The design method of gabion wall reinforced earth retaining wall is summarized.The design method of stepped gabion wall reinforced earth retaining wall considering gabion element and stress diffusion calculation mode in modified FHWA design method is optimized.(2)The PLAXIS 3D finite element software is introduced.Four kinds of indoor tests,such as screening test,compaction test,large triaxial shear test and drawing test,are carried out on the field soil samples.According to the test results,the numerical model of DDK6 + 170.102 section of stepped gabion wall reinforced soil retaining wall in Yichang North Station of Wuhan-Yichang section of Shanghai-Chongqing-Chengdu high-speed railway is established,which verifies that the project is stable and has certain safety reserve.(3)Using PLAXIS 3D finite element software,a comparative model of five factors,including step width,soil cohesion,internal friction angle,reinforcement stiffness and reinforcement length,was established.The base pressure,reinforcement tension,potential fracture surface,horizontal displacement of wall surface,vertical settlement and safety factor of stepped gabion wall reinforced soil retaining wall were analyzed and studied.It is found that the shear strength index and the length of the reinforcement have the greatest influence on the structural behavior of the stepped gabion wall reinforced soil wall,the stiffness of the reinforcement has the least influence,and the step width has the middle influence.(4)Based on the WK0 + 133.32 section in the project,the numerical model of the stepped gabion wall reinforced soil retaining wall with five different corner degrees of105 °,114 °,130 °,150 ° and 180 ° is established.The influence of the corner degree on the overall deformation of the stepped gabion wall reinforced soil retaining wall and the tension of the reinforcement is studied.Through the comparison of the five groups of models,it can be obtained that the smaller the corner degree,the larger the deformation of the stepped reinforced soil retaining wall and the larger the tension of the reinforcement,but the corner degree has little effect on the position of the potential rupture surface.