中文摘要：

针对有砟轨道加筋路堤计算分析中难以考虑土工格室对碎石填料嵌锁及摩擦作用的现状,在大比尺直剪试验基础上建立考虑填料–格室相互作用的三维计算模型。通过室内模型试验验证该计算的可靠度和优越性,进而系统地分析有/无加筋情况下,填料强度、土工格室刚度及地基压缩性等参数对路堤力学响应的影响。结果表明:土工格室的嵌锁作用使得加筋对路堤响应的影响在其布设层发挥程度更大,该影响通过填料与格室及填料内的摩擦作用向周围传递且不断衰减;填料强度较低或地基较软时能加强土工格室对路堤响应的影响,对于填料内摩擦角为20°和地基变形模量为5 MPa的工况而言,加筋后基床侧向位移峰值分别降低60%和72%,应力峰值亦显著降低且分布区域明显扩大;土工格室弹性模量为0.2~2.5 GPa时,路堤力学响应受其影响较大。

英文摘要：

The current analysis on reinforced railway embankment does not take the confinement and friction effects provided by geocell into consideration. To deal with this issue,a new model considering the interaction between the ballast and the geocell was proposed on the base of large-scale direct shear tests. The typical results of embankment behavior from the numerical computation agreed well with those from the laboratory model tests, which confirmed the reliability of the analysis model established. Further systematical analysis on the influence of the ballast strength,geocell stiffness and foundation compressibility on the mechanical response of embankment were carried out. The results showed that the reinforcement made significant influence on the embankment behavior especially near the reinforced layer due to the confinement from geocell. And the effect was spread to the surroundings through the friction provided by geocell and gravel itself and was dissipated gradually. The weaker ballast and softer foundation soil were found to enhance the reinforcement effect on embankment behavior in a greater degree. In the case when the internal friction angle of ballast was 20°and the deformation modulus of foundation soil 5 MPa,the peak lateral displacement was reduced 60% and 72% respectively. The peak stress decreased as well and the distribution range increased markedly due to the reinforcement. The mechanical response of embankment was found to be sensitive to the elastic modulus of geocell in the ranges of 0.2 GPa to 2.5 GPa.