Mesoscopic Simulation Of Geosynthetics Reinforced Soil Interface Interaction Mechanism Under Dynamic Loading

The action mechanism of interface on soil and geosynthetics decide the quality ofreinforced soil, study on interface on soil and geosynthetics under dynamic loading canreflect more truly the action mechanism. But now the study macro explore the mechanicalproperties of interface on soil and geosynthetics under dynamic loading of laboratory test,and based on the finite element method of continuum mechanics, numerical simulationsfor characteristics of interface on soil and geosynthetics, only analysis on macro property.The granular discrete element method get the macro mechanical properties of interface onsoil and geosynthetics and the variation law of micro-structure of soil. On the basis of thediscrete element particle flow code theory and PFC code, based on the results oflaboratory tests between soil and geosynthetics under dynamic loading, the paperconstitute the interface interaction on soil and geosynthetics model, study the mechanicalproperties of interface on soil and geosynthetics, and the development and changes ofmicroscopic variables, hope to further recognition on the evolution of fabric of sandparticle near interface on soil and geosynthetics.Based on the results of direct shear tests between geogrid and sand under cyclicloading, using particle flow code (PFC3D) to simulate the geogrid direct shear process.The displacement of particles are increased, cyclic loading peak valley values appearalternately, interface location soil porosity fluctuated?sand particles rotation obviously,sliding fraction is larger. With the deepening of embedded depth, the effects of cyclicloading were decreased, the peak value of shear stress increased, cyclic loading weakensthe reinforcement effect. The interlocking force, static friction force, sliding friction forceand rolling friction force are the main cause of forming reinforced effect.On the basis of the method of particle flow, using particle flow code (PFC3D) andrelative program to simulate the action mechanism of interface on soil and geosyntheticsunder vehicle loading. Geotextile in embankment is subjected to greater contact force inall time, geotextile and adjacent soil has formed greater contact force concentration area.Geotextile's adjacent soil was tighter, soil particle's mobile and rotation was weaker;vehicle loading has great influence on soil which is located upper side of geotextile, soilparticle's mobile and rotation was stronger.Based on the coupling method of discontinuum-continuum, the high fill reinforcedembankment is computationally modeled, the continuous element FLAC was adopted tosimulate peripheral region, and discrete element PFC was adopted to simulate localreinforced region. The force distribution of geogrid was analyzed embankment andchanges of the mesoscopic mechanism of geogrid treated embankment were studied:vehicle loading makes settlement and stress redistribution of soil and geogrid, geogrid'sreinforcement and tension can reduce differential settlement and diffuse stress.The paper using particle flow code to simulate the action of interface on soil andgeosynthetics under dynamic loading, which not only promotes the development of the granular discrete element, and acquired the change law of the macro and micro parametersfurther discusses the action mechanism of interface on soil and geosynthetics, buried depthand other issues proposed in the paper can also give reference for engineering.