Experimental Research And Engineering Application Of Modular Reinforced Earth Retaining Walls

Although the assembled retaining walls,principally of cantilevered and supported type,can reduce the problems of low construction efficiency and large project quantity induced by traditional gravity masonry structures,while the construction costs still high due to the heavy component weight,difficulties in transportation,lifting,and securing the strength of the nodes.As a prefabricated light retaining structure,modular reinforced earth retaining wall is economical and beautiful,and with high deformation resistance and simple construction,and it can be planted and afforested through the structural transformation of the panel,which can effectively promote the standardization and ecology of the retaining structure.Based on the construction of the retaining structure of a fill roadbed section of the Hangzhou Bay Ring Expressway(Hangzhou-Ningbo section),the experimental study on mechanical and deformation characteristics of modular reinforced earth retaining wall,and the engineering application research of ecological modular reinforced earth retaining walls were carried out through laboratory,field tests and numerical simulations.The main work and conclusions are as follows.1.A model of modular reinforced earth retaining wall with upright wall type was made in the laboratory,and the graded loading and graded static load were applied to the top of the wall successively.the stress,deformation and strain of the reinforcing material of the wall during the loading process were tested by the earth pressure box and flexible displacement meter and other components buried in the model.The results show that:during the loading and unloading period,the stress and deformation of the retaining wall increase rapidly and then stabilize with the increase of loading times,and the amplitude increases gradually with the increase of loading level;the horizontal displacement of the wall surface increases and then decreases along the wall height;the vertical stress in the wall is distributed non-linearly along the direction of the tendon length;the horizontal distance between the peak position of the grating strain and the wall surface increases with the increase of wall height.2.Based on the model test results and the actual engineering requirements,the prefabricated panel structure was modified and an eco-modular reinforced earth retaining wall with planting trough was designed.And the construction process and quality control requirements were summarized.The results show that: the vertical stress in the wall and the horizontal stress near the wall surface increase with the increase of the filling height,and the overall geogrid strain tends to increase;the vertical stress and the grating strain vary non-linearly along the length of the reinforcement;the horizontal distance between the bottom of the linear potential rupture surface and the retaining wall is 1.77 m.3.A three-dimensional finite element calculation model was established according to the ecological modular reinforced earth retaining wall at the actual working point.And the calculation of the force and deformation of the modular reinforced earth retaining wall under various working conditions was carried out by changing the modulus of elasticity of the reinforcement,the inclination angle of the wall,the reinforcement spacing and the height of the retaining wall.The maximum tensile stress of the reinforcement increases significantly with the increase of the modulus of the reinforcement or the reinforcement spacing.