Abstract: A three-dimensional coupled mechanical and hydraulic model was built by using the finite-difference continuum program (FLAC3D) based on an inter-city railway. The comparison analysis of the time-dependent behavior of the GRPS embankment of the soil with medium-low compressibility was carried out. The variation rule of excess pore water pressure, settlement at the center of sub-grade surface, and horizontal displacement at the embankment toe changing with the time under the condition of the unreinforced ground and the ground reinforced with GRPS were elaborated in detail. The results show that GRPS could effectively control the ground deformation of soil with medium-low compressibility during and after the embankment construction, which prevents the failure and instability of foundation under the embankment load.

Key words: highway engineering, soil with medium-low compressibility, geosynthetic-reinforced and pile-supported embankment, time-dependent behavior, excess pore water pressure, post-construction deformation

摘要： 以某城际铁路为背景，采用有限差分软件FLAC3D建立三维流固耦合模型，对中低压缩性土地基桩承式加筋路堤的时效性进行对比分析，重点探讨了不加固和桩承式加筋两种工况下地基中超孔隙水压力、地基表面中心沉降和路堤坡脚水平位移随时间的变化规律。结果表明：采用桩承式加筋路堤可以有效控制中低压缩性土地基的路堤填筑施工变形和工后变形，防止地基在路堤填土荷载下发生失稳破坏。

关键词: 道路工程, 中低压缩性土, 桩承式加筋路堤, 时效性, 超孔隙水压力, 工后变形