Experimental Research And Numerical Simulation On Interface Interaction Between Coarse Grained Soil And Geosynthetics

With the continuous economic development of our country, the reinforced earthtechnology has been widely applied to civil engineering construction. With its superiorengineering properties, geosynthetics materials as an important kind of reinforcedmaterials are widely used in reinforcement engineering. Geosynthetic reinforcement ofreinforced soil interface function also gradually became a focus topic of geotechnicalengineering research. Although domestic and foreign scholars have conducted a lot ofresearch on the interaction mechanism of reinforced soil interface, because of varieties ofinfluence factors, the interface mechanism is very complex. Especially the research ofreinforced soil interface mechanism of reinforcement of coarse grained soil which isrelatively lacking at present, it still needs further research on reinforced soil interfaceproperties.The three-dimensional numerical models of reinforced coarse grained soil triaxialtests are simulated based on the geogrid reinforced laboratory triaxial tests, which belongto the discrete element method. Based on the results of lab triaxial tests, the influence ofmesoscopic parameters changes on the macroproperties of sand sample are discussed. Themesoscopic parameters include friction factor, stiffness ratio of particle, etc. Try toestablish internal relations between macro-mesoscopic mechanical variables, and revealthe mesoscopic rule of reinforced soil interface interaction. The reinforced layer effect onthe macro-mesoscopic nature and internal mesoscopic fabric of triaxial samples werestudied. And it was applied to guide the engineering practice.Applications and secondary development PFC3D, the triangle non-circular particleshas been developed and used to establish the model of reinforced coarse grained soiltriaxial tests. The simulation results are compared with pure round particles triaxial testresults. The influence of external shape of soil particles on the macro-mesoscopicproperties of reinforced coarse grained soil triaxial samples are analyzed.The pull-out test of reinforced coarse grained soil was conducted to study themacroscopic and mesoscopic mechanism by the tutor designed model of the largevisualization device. Using the high-definition digital camera to capture images during thereinforcement material pull-out process. The influence of the change of the coarse materialcontent of the coarse grained soil P5, geogrid embedded length and overlying stress oninterfacial properties of reinforced soil were respectively considered. Usingpost-processing software for further processing of images, research and analysisthe movement rule of soil particles around reinforced soil interface in the process ofreinforced coarse grained soil pullout tests. Study on reinforced coarse grained soilinterface interaction mechanism through the laboratory tests and particle flow numericalanalysis method. From the angles of macroscopic and mesoscopic studies the movementof soil particles around reinforced soil interface and the interaction between the reinforcedsoil, reveals the reinforcement mechanism of coarse grained soil reinforcement soil interface. Research shows that the increase of coarse material content, geogrid embeddedlength and overlying stress can improve the resistance peak of pull-out samples. Thechange of coarse material content and geogrid embedded length have a great impact on thedisplacement evolution and strain evolution of the reinforced coarse grained soil interfaceof pull-out sanples.