(1. Institute of Geotechnical and Underground Engineering，Huazhong University of Science and Technology，Wuhan，Hubei 430074，China；2. Key Laboratory of Highway Construction and Maintenance Technology in Loess Region，Shanxi Transportation Research Institute，Taiyuan，Shanxi 030006，China)
Abstract：The interface characteristic of geogrid and compacted materials plays an important role in the design of reinforced soil structures. The pull-out test of triaxial geogrid was conducted by 3-D discrete element method to investigate the correlation between macro and meso mechanical responses. Simultaneously，the influence of particle size on reinforcement effect was discussed. The mechanical behavior of reinforced soil and geogrid under pull-out loading was systematically analyzed. The evolution law of the pull-out force and mesoscopic fabric anisotropy indices was shown. Based on the pull-out test results，an assessment method was established to estimate the reinforcement effect of geogrid. Numerical results reveal that the velocity vector of particles in the interfaces can reflect the interaction between geogrid and soil instantaneously. The fabric anisotropy coefficient is suitable to describe the development of macroscopic strength. In a certain particle size scope，the reinforcement effect would be primarily controlled by the specific surface area of grain system and the critical edge load of reinforced soil would decrease with the increase of particle size.
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2016, Vol. 35 
