高速铁路沥青道床材料的破坏模式与特征参数

项目名称： 高速铁路沥青道床材料的破坏模式与特征参数

项目编号： No.51308429

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 方明镜

作者单位： 武汉理工大学

项目金额： 25万元

中文摘要： 道床材料直接影响高速铁路的运营安全、行车舒适与服务寿命。密级配沥青混凝土用于高速铁路道床支承层具有防水、减振、降噪、适应路基变形、易于维护且环保可回收等优势，但沥青层材料在轮轨荷载作用下存在损伤、劣化甚至破坏之风险。项目基于材料损伤与断裂力学理论，以沥青道床破坏模式与特征参数为内容，围绕解决道床沥青层受力状态与边界约束影响道床材料损伤演化作用机制的关键问题，采用理论分析、粘弹性有限元数值计算、室内沥青混凝土试件弯曲与单轴压缩破坏试验，结合相关实测资料，合理选取高速铁路沥青有砟和沥青无砟典型道床形式，并引入沥青混合料疲劳开裂机制，开展道床沥青混凝土材料的损伤演变、劣化机理及破坏行为研究，提出沥青道床材料的关键力学指标和破坏判定准则，揭示高速铁路道床沥青混凝土材料的破坏模式，构建沥青道床材料的破坏特征参数评价体系。研究成果可为我国高速铁路全断面沥青混凝土支承层的结构设计与工程应用提供理论指导。

中文关键词： 高速铁路；沥青混凝土；道床；破坏模式；特征参数

英文摘要： The materials of trackbeds directly influence the operation safety, ride comfort and service life of high-speed railways. The well-graded asphalt concrete trackbeds applied in high-speed rails perform well in low permeability, noise reduction and vibration control as well as sufficient strength and appropriate flexibility. However, the risk on damage deterioration and even fracture or failure exists in the asphalt bearing layer when subjected to the high-speed wheel-rail loads. In this project, according to the theories of material damage and fracture mechanics, the failure modes and characteristic parameters were taken as the research contents around the key issue that the loading conditions and the boundary constraints of subtrack asphalt layer influence the mechanism of action for damage propagation of trackbed materials. In which, using the theoretical analysis, the visco-elastic finite element method (FEM) and the laboratory tests including bending fracture test and uniaxial compression test as well as the field tests data related to existing trackbeds, the conventional asphalt trackbed and the ballastless asphalt trackbed with appropriate asphalt layer were selected respectively as the research structures, and the fatigue cracking principle of asphalt mix was introduced to analyze the damage evolution,

英文关键词： High-Speed Railway；Asphalt Concrete；Trackbed；Failure Modes；Characteristic Parameters