Study On The Mechanical Characteristics And Influencing Factors Of Geocell Reinforced Soil Retaining Wall

Geocell is a three-dimensional geosynthetic material with net shape.Due to its stereoscopic structure,geocell can also additionally provide strong lateral binding force to the filler material compared with geogrid,geotextile and other flat reinforcement materials that only rely on their own tensile strength and the friction between the tendons and soil to provide reinforcing effect.Compared with rigid retaining walls made of slurry stone and concrete masonry,geocell reinforced earth retaining walls not only have advantages of light in structure,easy to take materials and convenient in construction,but also can greening of slopes.In this paper,relying on the protection and ecological greening of the subgrade of the Jinqu-Hang Shaotai Expressway Liaison Project,the characteristics of the reinforced soil interface of geocell reinforced soil,the force characteristics of the retaining wall under vertical load and the design influencing factors are studied by using laboratory tests and numerical simulations,respectively.The main work and conclusions of the paper are as follows.(1)The pullout tests of geocells with different fillings and different reinforced materials in the same fillings were carried out using self-designed and processed pullout test chambers.The test results of pullout displacement and pullout force analyzed the tendon-soil interface characteristics of geocell reinforced soils.The results show that,the interfacial resistance coefficient of geocell reinforced gravel soil is larger than that of reinforced clay soil;the interfacial friction characteristics of reinforced geocell are significantly better than those of flat reinforcement materials such as geogrid and geotextile.(2)A reduced-scale model of geocell reinforced retaining wall was filled,and vertical graded loading and unloading were applied on the top of the model wall.The stresses,deformations and strains of the retaining wall during the filling and loading of the model were tested by displacement meter,stress box and other sensors.The test results show that: the vertical stress in the retaining wall varies nonlinearly along the length of the compartment,and the maximum value is located in the middle of the retaining wall;the horizontal stress at the back of the wall decreases gradually with the increase of the retaining wall height,while the horizontal displacement increases and then decreases;the maximum value of vertical deformation of the wall is located at the top of the wall;the large deformation of the geocell is mainly generated during the filling period,and the adverse effect of the construction process on the geocell should be controlled.(3)Taking the proposed geocell reinforced earth retaining wall as the object,the finite element numerical model was established,the calculation results are compared with the measured results of similar projects,and the calculation of retaining wall force and deformation under various working conditions was carried out,which can provide reference for the reasonable selection of retaining wall design parameters.The calculation results show that: the vertical stress in the wall and the variation law of wall displacement along the wall height are similar to the test results of similar projects;the horizontal displacement of the wall is influenced by the reinforcement spacing and the slope ratio of the retaining wall,and gradually decreases with the increase of the modulus of the compartment and the thickness of the wall.