Study On The Standard Contrast And Mechanical Properties Of Reinforced Earth Retaining Wall

Reinforced earth retaining walls have many advantages,such as convenient construction,beautiful and diverse modeling,adapt to various working conditions,save manpower and material resources,and it can be used in the design of rapid transit railways and expressway.In the design of subgrade,in particular,the rapid transit railways has strict requirements for the settlement of the subgrade,the excessive settlement of the subgrade will have a serious effect on the stable operation of the rapid transit railways.In this paper,the current research status of reinforced soil technology at home and abroad is summarized and summarized,through the comparative analysis of the different countries standard,the static load model test of reinforced earth retaining wall and the numerical simulation of the model test,and through the above three aspects to carry out the study.The main contents list as follows:(1)There is difference of the design approach with the reinforced retaining wall in different countries.The designed calculation comparison of reinforced retaining wall has been taken according to Chinese,Britain and the United States design code based on some slope engineering.The analysis focused on the diversity of the formulas and calculation on the earth pressure,reinforcement strength,pullout resistant stability and anti-slip stability.The results show that the calculation of pullout resistant stability and horizontal anti-slip stability of British code is superior to that of Chinese and American codes,which reflects that the limit state method is closer to the actual situation.Different partial coefficients used in the British code can simulate actual conditions more precisely,which makes the design of the reinforced retaining wall more economical and reasonable on the premise of security restriction.(2)Model test in laboratory were carried out to study the behaviors of reinforced earth retaining wall of block face under the loading on the top of the retaining wall.In the model test,four conditions were simulated.The variables were the number of the reinforced layers,the length of reinforcement and the type of reinforcement.Under the four conditions,the vertical soil pressures,the lateral displacement of wall face,vertical deformation at the top of wall and the tension strain of reinforcement were measured.The vertical earth pressure on the top of retaining wall increases rapidly,the maximum vertical earth pressure of each layer moves from the lower part of the loading point to the face of wall.When the load at the top of wall exceeds 130 KPa,due to uneven settlement,fourth layers of reinforcement correspond to the face of wall have an inward shrinkage trend,the maximum horizontal displacement of wall surface is 7/10 of the wall height.In the whole loading stage,the overall strain value of the reinforcement is not increasing significantly,the actual strain value of the reinforcement is much smaller than the maximum design strain of the reinforcement.Increasing the number of the reinforced layers in the retaining wall and increasing the length of reinforcement can improve the performance of the retaining walls,the effect of increasing the number of the reinforced layers is better than that of increasing the length of reinforcement.The use of waste tire instead of unidirectional geogrid can effectively improve the overall performance of retaining walls,it can effectively disperse additional stress caused by overloading,reduce the horizontal displacement of the face of wall and reduce the vertical displacement at the top of the wall.(3)Through the static load model test of reinforced earth retaining wall,the corresponding numerical simulation is carried out,and the reliability of the data can be verified by comparison of data.The simulation of the four working conditions of the test is carried out respectively,and the vertical earth pressure in the wall,the horizontal displacement of the facing block,the vertical displacement of the wall and the strain of the reinforcement in the four cases are compared and analyzed.The research shows that the simulated data coincide with the data obtained from the tests approximately.The vertical earth pressure on the top of the retaining wall is increasing rapidly and the maximum value of vertical earth pressure is moved from the under loading point to the back of the wall.Using waste tire instead of geogrid as reinforcement can effectively improve the overall performance of retaining wall.