移动荷载作用下桩承式加筋路堤的动力特性

为了研究桩承式加筋路堤在移动荷载作用下的特性,采用FLAC 3D软件建立了移动荷载作用下道路的三维动力流固耦合分析模型,对桩承式加筋路堤和天然路堤在移动荷载作用下的竖向变形、桩土应力比、超孔隙水压力、加速度等进行了对比分析,并研究了不同轴载对路堤竖向变形的影响.分析结果表明:移动荷载作用下,桩承式加筋路堤通过桩体土拱效应和格栅张拉膜效应的联合作用,其路面竖向变形、桩土应力比、超孔隙水压力、加速度均比天然路堤的结果明显减小；随着轴载的增加,桩承式加筋路堤路面竖向变形不断增大.

Dynamic Behavior of Geogrid Reinforced Pile Supported Embankments under Moving Load

In order to investigate the dynamic behavior of geogrid-reinforced pile-supported embankments （GRPS） under moving load, a three-dimensional coupled mechanical and hydraulic model was built by FLAC 3D. The results from two cases including unreinforced and no-pile embankments, and geogrid- reinforced pile-supported embankments were presented. The behaviors of vertical displacement, pile-soil stress ratio, excess pore water pressure, and vertical acceleration under two cases were compared and discussed. Additionally, studies on the effect of speed and weight of the moving load were performed. It is indicated that the value of vertical displacement, pile-soil stress ratio, excess pore water pressure, and vertical acceleration of GRPS decrease evidently compared with those of unreinforced and no-pile embankment, which is caused by the soil arching effect and the reinforcement effect. It is also shown that the greater the axle load value is, the less the beneficial effect of GRPS on the vertical displacement. With the increase of the moving speed of the load, the vertical displacement increases.