Study On Soil Arching In Piled Embankment Based On PFC

This paper research piled embankment. Based on the theory of distinct elementmethod, use PFC software to simulate soil-arching effect in piled embankment. Twodiscussed aspect is mechanism and utility of soil-arching effect in piled embankment.On one hand, treat the soil as discrete particles, through simulating model test, toresearch the soil-arching effect in deep. On the other hand, take the field test of piledembankment in Jiangsu province as foundation, analyses the response of soil-archingeffect in piled embankment at the time of parameter changing. Main content follows:At present, the study on soil-arching effect in piled embankment is still limited tomacro level, and the study on the motion、force and interaction of particles is very shortin micro level. It is important to explore the mechanism of particle behavior from microview. This paper, at first, establish PFC model, and simulate model test of planesoil-arching in piled embankment. Four key point deliberated in this paper areforce-chain distribution、porosity changing、average coordination number changing anddisplacement waving of particles in the process of soil-arching form. research output:①The porosity change all the time, and mutate sometime in soil-arching form process.②Following the relative displacement increase, the average coordination number wavegreatly. This phenomenon proves that the soil-arching form process is a variable process.③For particle movement, the displacement of particle movement in the place of shearbelt is bigger than other parts of embankment. The shear belt will develop an reverse“V” shape. If the height of the embankment is different, the vertical displacement willhave different value. If a partial arching occurs in an embankment, hunches with“mushroom” shape will form on the surface of the embankment.④For particlerotation, the average pure rotation rate picture shows that different particles nearpile-beam have huge diversity in particle rotation. Following the relative displacement increase, the particle average rotation rate has no great change. The normal componentsof particle contact force turn obviously, and form an arching shape gradually.Soil arching effect in piled embankment not only has relationship withembankment, but also has closely connection with composite foundation. Aftermechanism research, this paper simulate practical project. Study practical soil arching inpiled embankment, and research the response of soil arching in piled embankment whenparameter change. Result shows: The stress concentration ratio increases with theaugment of the radius of pile, but decrease with the augment of the distance of piles.When the friction of particles adds, the stress concentration ratio increases. If the heightof embankment adds, the stress concentration ratio will increase. When the heightreaches one point, the stress concentration ratio gets biggest value. After this point, thestress concentration ratio decreases, but not great.