摘要 在中非共和国大约超过80%的道路网络系统为天然土壤、土方或者碎石的未铺路面道路。这个数据还没有包括小或者农村道路，据估计这样的道路有8，000到10，000km 这样的未铺路面道路在恶劣的情况下尤其在雨季，普遍存在着道路坑洼几乎不能形为路。季期间道路非常多尘土在社区里肆虐造成极大的卫生危害。 面对着这些问题和中非共和国，道路闭塞的国家这个事实，政府部门已经计划自主建立一个覆盖全国的道路网络系统。政府目标到2030年建设新道路，同时改善和升级现有道路的质量。自主计划包含了所有国内道路，也包括了中非共和国的边境地带。这个目标如果达成将会带来巨大的国民社会经济利益。 从经济意义考虑提供更好的质量和长寿命路面使用性能，重点放在路面设计，为什么做这项研究，其目的是：（1）通过对现有材料和运输需求和适应现代技术，中非共和国可以更好地了解以改善路面性能为目标的气候和交通的研究方案；（2）确定材料的质量将在不同层使用，这些层将不得不提供一个很好的防止反射裂缝的性质；（3）确定道路的长期结构性能；（4）选择一类混合料设计，能够确定不同层级里不同材料表征与特性。（5）可用如ANSYS之类的软件对路面结构特性进行分析，以观察其在负荷和气候的影响下的特性；（6）实现以最经济的方式延长路面使用寿命，对未来特定累积交通荷载的强度和密度，估算两个或两个以上拥有低成本的软性路面材料构成很有必要，从而使中非共和国政府省钱用于其他地方的经济建设。 关键词：道路工程，柔性路面结构设计与分析。 ABSTRACT Approximately, more than 80% of the road networks in the Central African Republic (CAR) are unpaved roads of natural soil/earth or gravels. This figure does not cover small or rural roads, which is estimated to be in the range of 8,000 to 10,000km. These unpaved roads are generally in poor condition especially during the wet season, where the roads are undulating and almost impassable. During dry season the roads can be very dusty posing health hazard to the surrounding community (African Development Bank/ United Nations Economic Commission for Africa, 2007). Faced with these problems and the fact that the Central African Republic (CAR) is a landlocked country, the CAR government has proposed a countrywide road network initiative. The government aims to construct new roads and also improve and upgrade the quality of existing ones by the year 2030. This initiative covers all roads in the country as well as those links to the countries CAR is bordered with. This goal if achieved will have immense socio-economic benefits to the people of CAR To provide better quality and long-life pavement performance within economic means, emphasis is placed on pavement design, which is why the objectives for this study are (1) to implement a program of research aimed at improving the performance of road pavement, through a better understanding of the available materials and transport demands and the adaptation of modern techniques to Central African Republic climates and traffic; (2) to determine the quality of materials to be used in different layers, and these layers will have to provide a good road surface with very good spreading properties that prevent reflection cracks, (3) to determine the long-term structural performance of the road; (4) to select a type of mix design that will be useful in determining the characterizations and properties of different materials to be used in each layer; (5) an appropriate software like Ansys will be used to analyze the pavement structure behavior, in order to observe its behavior under load and climate effects, (6) to achieve additional pavement life in the most economic manner , it will be necessary to quantity the future strength and thicknesses for a particular cumulative traffic loading, and estimate two or more variants with better costs for materials composed in flexible pavement, thus enable the CAR government to save money which can be used elsewhere for economic growth. Key Words: Road Engineering, Structural Design of Flexible and analysis. |
硕士论文