基于界面力学的水泥混凝土路面传力杆传荷失效机理的研究

项目名称： 基于界面力学的水泥混凝土路面传力杆传荷失效机理的研究

项目编号： No.50808058

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 化学工业

项目作者： 薛忠军

作者单位： 哈尔滨工业大学

项目金额： 20万元

中文摘要： 针对水泥混凝土路面传力杆的传荷性能及疲劳损伤机理问题，本项目从接缝传力杆的传荷特性着手，建立了设传力杆的水泥混凝土路面接缝结构的力学分析模型，采用数值仿真和实验研究相结合的方法，研究了传力杆和水泥板自身材质、结构组合、载荷大小、板底脱空、界面损坏等因素对传力杆传荷特性的影响规律；研究了传力杆与混凝土界面的接触应力及弹塑性破坏规；基于界面力学理论，利用声发射技术，通过疲劳试验研究了传力杆与混凝土界面的损伤演化发展规律。研究结果表明通过增大传力杆直径、增加数量、提高混凝土等级、增加混凝土板厚等手段，均可提高混凝土路面接缝的传荷能力；因车轮作用在板角、板底脱空、基层模量提高等因素，均导致混凝土路面接缝的传荷能力降低；增加传力杆直径可以有效减小传力杆疲劳损伤的发生。提出了利用传荷系数评价传力杆传荷特性的评价方法及评价指标；拟合得到了损伤演化方程，提出了传力杆的传荷失效判据；通过电化学加速锈蚀试验方法，在损伤力学和声发射速率过程理论的基础上，建立了考虑初始损伤的混凝土损伤因子计算方法，可定量研究不同锈蚀程度下传力杆与混凝土接触界面的锈蚀损伤情况，并通过锈蚀损伤方程可计算锈蚀量的初始损伤百分比。

中文关键词： 传力杆;传荷特性;界面力学;疲劳;有限元

英文摘要： This project focused on the load transfer efficiency and fatigue damage mechanism of dowel bar in dowel-jointed pavement. In this project, load transfer characteristic of dowels was consider as the major point, mechanical model of the pavement joint with a group of dowels was established. In this project, the experimentation as the main research method was combined with the theoretic study and numerical analysis. The study of this project has major contributions to the influence law of load transfer characteristic of dowel to the factors such as material quality of cement plate, structural assembly, load quantity, slab void, interface damage etc.Bearing stresses in the concrete surrounding the dowels which causes the concrete to crush and spall locally and the elasto-plastic failure law was researched.Combined with interface mechanics theory, based on acoustic emission, the damage regularity of the interface between dowel and concrete was researched by means of fatigue tests.It is concluded that the following method were effictive to improve the load-transfer capacity, such as increasing the diameter of dowel bar, increasing the quantity, improving the concrete grade and increasing the thickness of concrate slab etc. It is also indicated that the following factors may cause a decrease in the load-transfer capacity of the pavement joint, such as the wheel action point in the corner of slab, slab void, increasing the base module etc. Increasing the diameter of dowel bar were proved to be an effective way to reduce the fatigue damage. The evaluation method and index of the load transfer characteristic were also indicated. Equation of damage development were fitted, loading failure criterion of the dowel was also indicated. By means of galvano-chemistry acceleration corrosion test, based on the damage mechanics and speed process of acoustic emission theory, calculation method of concrete damage factor which was considering as the initial damage was established. Quantitative research were conducted on the corrosion damage of the interface between dowel bar and concrete under different level of corrosion, the initial percent of corrosion damage were calculated according to the equation of corrosion damage.

英文关键词： dowel; loading transfer characteristic; interface mechanics; fatigue; finite element method