沥青混凝土面层式基床轨下基础疲劳损伤机理研究

The asphalt concrete is a tranditional material for constructing highway pavement, provided with advantages of good bearing capacity, water repellency, shock absorption and noise reduction. It is gradually used for constructing the railway subgrade bed under rail, however, the researches about the durability and fatigue damage mechanism of subgrade bed with asphalt concrete surface still have to be further studied. Based on the previous research results about the railway asphalt concrete, the applicants are going to carry out researches about the dynamic response, damage model and fatigue life of the asphalt concrete subgrade bed. The dynamic response parameters and other performance parameters of the railway asphalt concrete are planned to be measured by using the modified tranditional tests of highway asphalt pavement, and also the dynamic model test will be used to get the dynamical responses and the damage models of the asphalt concrete subgrade bed under the repeated loading of train. Furthermore, the sensitivity analysis of influencing factors on the dynamical responses and the damage models will be studied by using the numerical simulation and the regression analysis, to set up the fatigue life prediction model of the asphalt concrete subgrade bed. The research results are supposed to provide theoretical basis and technical support for the application of the asphalt concrete in the foundation under rail.

沥青混凝土作为公路路面常用材料，具有承载力好、防水性强以及减震降噪等优点，逐渐被应用到新型铁路轨下基础基床结构中，然而对于其耐久性问题尚无定论，因此有关沥青混凝土面层式基床轨下基础疲劳损伤机理还有待进一步的研究。在申请者对有关铁路沥青混凝土前期研究工作的基础上，本课题拟围绕沥青混凝土面层式基床轨下基础结构动力学响应、损伤模式以及疲劳寿命预测等方面开展研究。通过室内材料参数试验测定铁路沥青混凝土动力学参数、抗水损参数、抗弯拉性能以及温度敏感性参数，采用室内动力模型试验测定沥青混凝土面层式基床轨下基础结构的动力学响应规律和损伤模式，结合数值仿真计算和回归分析等研究手段，开展其结构动力学响应及疲劳损伤影响因素的敏感性分析，建立沥青混凝土面层式基床轨下基础结构的疲劳寿命预测模型，为沥青混凝土在铁路轨下基础结构中的应用提供理论基础及技术支撑。

沥青混凝土作为公路路面常用材料，具有承载力好、防水性强以及减震降噪等优点，逐渐被应用到新型铁路轨下基础基床结构中，然而对于其耐久性问题尚无定论，因此有关沥青混凝土面层式基床疲劳损伤机理还有待进一步的研究。本课题在对有关铁路沥青混凝土前期研究工作的基础上，围绕沥青混凝土面层式基床结构动力学响应、损伤模式以及疲劳寿命预测等方面开展了系统研究。通过室内材料参数试验测定铁路沥青混凝土动力学参数、抗水损参数、抗弯拉性能以及温度敏感性参数，采用室内足尺动力模型试验测定沥青混凝土面层式基床结构的内部动力学响应规律和损伤模式，结合数值仿真和回归分析等研究手段，开展其结构动力学响应及疲劳损伤影响因素的敏感性分析，建立沥青混凝土面层式基床结构的疲劳寿命预测方法，相关的研究成果可以促进沥青混凝土在铁路轨下基础结构中的应用。