桩承式路堤中加筋褥垫层的工作性状

建立桩承式加筋路堤三维有限元模型，对比分析多层土工格栅与单层土工格栅情况下软土表面沉降、软土表面竖向应力与加筋体应变的分布规律.研究发现：软土表面的沉降仅与土工格栅的总强度有关，而土工格栅的层数对软土表面的沉降影响不大；对比单层与三层加筋体模型结果可知，三层加筋体能更明显地减小作用在软土中心的竖向应力，从而使得两桩之间的竖向应力分布更加均匀.在土工格栅总强度相同的情况下，多层加筋体底层土工格栅的最大应变是单层加筋体的1.38~1.50倍.

Working performance of reinforced cushion in piled embankment

A three-dimensional finite element model of geosynthetic-reinforced piled embankment was established. The distribution law including the settlement of subsoil surface, the stress of subsoil surface and the strain of geogrid were analyzed by comparing the results of the embankment reinforced by single and multiple layers of geogrid. It is found that the settlement of subsoil surface obviously depends on the total stiffness of geogrid, while is slightly influenced by the number of geogrid layers. Compared with the results of the embankment reinforced by single layer geogrid, three layers geogrid can more obviously reduce the vertical stress acting on the center of subsoil, and therefore resulting in more uniformly distribution of the vertical stress between piles. It also can be observed that the maximum geogrid strain for the bottom layer geogrid is approximately 38% to 50% larger than that of the single layer geogrid under the condition that the total stiffness of geogrid is the same.