基于PFC的桩承式路堤土拱效应机理研究

应用PFC3D软件，模拟桩承式路堤土拱效应，分析土体颗粒体系中力链的分布情况及土体孔隙比、配位数与土拱效应的关系。研究结果表明:桩土相对位移出现时，路堤土体中力链明显偏转，并发展成一拱形；土体成拱过程中，孔隙比会发生突变；桩土相对位移对路堤土体的影响存在渐进性；配位数在路堤土体中的分布，呈现中部高于上、下部的趋势，证明土拱拱体的形成；在较小或较大相对位移情况下，土体内部颗粒运动比较活跃，土拱效应发挥明显。

Study on Mechanism of Soil Arching Effect in Pile-supported Embankment Based on PFC

With PFC3D software, soil arching effect in pile-supported embankment was simulated; distribution of force chains in soil particles system, and relation between the porosity and coordination number and the soil arching effect were analyzed. The study results show that when pile-soil relative displacement occurs, the embankment has the force chains therein deflected obviously, and then develops into an arch gradually and, in the process of soil arching, the porosity may change suddenly. The effect of the relative displacement on the embankment is gradual. The distribution of the coordination number in the embankment shows a tendency of that in the middle part larger than that in the upper and lower part, proving the formation of the soil arch. When the relative displacement is too small or too large, the particle movement inside the soil mass is active and the soil arching effect plays its role obviously.