【作者】 黄菲；

【导师】 黄晓明；

【作者基本信息】 东南大学 ， 道路与铁道工程， 2006， 硕士

【摘要】 沥青混合料的永久变形(车辙)是柔性路面体系最重要的几种破坏类型之一。车辙直接影响路面的平整度和路面使用性能,对汽车行驶的安全性造成危害,而且车辙深度不断积累会造成路面的严重病害。因此实用、合理地预估车辙在我国现阶段的路面设计和管理中是十分必要的。本文参照国内外车辙预估方法,运用ABAQUS有限元软件对沥青路面永久变形进行数值模拟并给出合理的预估方法。首先根据沪宁高速扩建项目研究,在重庆交科院进行了大型的环道试验。通过对不同基层的路面结构进行高温下的重复加载试验,来模拟实际道路的行车条件。从而分析柔性基层和半刚性基层路面结构在不同交通荷载下的应力、应变和位移响应,以得到沥青路面永久变形与加载次数之间的相关规律。其次对有限元方法的基本理论进行了介绍,着重分析ABAQUS方法中蠕变模型的原理,以及运用其分析沥青混合料特性的可行性。根据环道试验的相关数据,进行蠕变试验得到沥青混合料的材料参数,并在合理的假定和简化基础上应用有限元软件建立模拟沥青混合料车辙变形的模型,对不同结构在重复荷载下的变形进行数值模拟和分析;考虑到我国目前车辆超载超限运输情况十分严重,利用有限元计算方法对重载条件下的车辙形成与发展规律进行分析。着重研究不同结构在不同轴载下的车辙响应,并在数值模拟数据的基础上提出基于车辙等效的轴载换算方法,为重载道路的设计和车辙预估提供一些有价值的理论资料。最后结合试验路的路面结构研究,对车辙预估公式加以修正,并与环道结果相比较。更多还原

【Abstract】 Permanent deformation (rutting) of HMA is one of the major structural failures of flexible pavements. Significant rutting may influence the smoothness and roughness of asphalt pavements, and endanger the security of running cars. The increased rutting also causes severity diseases of the pavement surface. So predict the potential rutting level practically and reasonably is important in the design and management of the pavement. According to the methods of rutting prediction both at home and abroad, the permanent deformation value was simulated using finite element program ABAQUS. And a reasonable prediction method was given in this paper.At the beginning, the large scale circular track testing equipment of Chongqing Commnications Research and Design Institute was adopted to simulate real condition of asphalt pavement structure after high temperature. Three types of pavement structure included semi-rigid base and flexible base were produced and analyzed the inherent stress, strain and displacement of asphalt concrete, after about 500,000 repeated loads. Then formation mechanism of rutting and compare the existing methods.Secondly, the basic theory of finite element method was introduced. The emphasis was the creep model in ABAQUS and the possibility of using it analyzing asphalt mixture. According the interrelated data of the track testing, the material parameters of asphalt mixture were gained from creep test. A model of pavement by finite element software, ABAQUS, was built to simulate the permanent deformation of asphalt pavement, based on reasonable supposition and predigestion. The numerical results were compared with the track test and indicated that the approach was reliable.Considering the over loading of vehicles was very severity in our country, finite element method was used to simulate the asphalt pavement under heavy duty traffic. The purpose was to find the process of rutting forming and growing, especially the rutting of different structures under repeated loads of varies axles. With all research results above in the calculation, a method regarding rutting depth was developed. These provided some valuable theory for design of over loading pavement and prediction of rutting. Finally, integrated the research on pavement structure of test road,the equations were modified and compared with the results of track test in this study.更多还原