【作者】 华政辉；

【导师】 罗强； 黄关丁；

【作者基本信息】 西南交通大学 ， 建筑与土木工程， 2002， 硕士

【摘要】 在世界各国的经济发展中，公路运输起着极为重要的作用，投资也愈来愈大，并朝着重型、密集、高速化方向发展。重型货车、高速客车、密集车流对路面路基结构的服务品质提出了越来越高的要求。研究表明，路面路基结构的沉降变形主要来自地基路堤土层的固结压密沉降和交通荷载反复作用下路面路基各结构层的累积残余变形，路面路基结构发生过大的沉降变形会使路面过早破坏。路面的早期破坏问题对公路的正常使用影响十分较大，已引起了公路建设行业的高度重视。关于路面路基结构在车辆荷载作用下的动力特性试验研究，目前在国内开展得较少，因此非常有必要进行室内大型动态模型试验，深入研究路面路基结构在交通荷载作用下的动力响应特性。 本论文针对国道108线广元段广北二期工程的路面路基结构及使用状态进行了试验研究。按照国道108线广元段广北二期工程的路面路基的实际结构型式进行了室内足尺大型动静态模型试验。为使其边界条件尽量同实际情况一致，模型周围采用了砂袋作柔性挡土边墙。通过静力加载和模拟路面承受的竖向交通荷载的重复加载试验，研究了路面路基结构在双轮车辆荷载作用下的动静态响应，分析了路面路基结构在浸水状态(土层含水量增加)和压实密度降低等不利因数的影响下，路面路基各结构层的动静力学响应特性，如弹性变形、累积下沉、土压应力等的变化规律。 试验研究结果表明：在路面路基结构各土层压实密度基本一致的条件下，水的浸入(土层含水量增加)将会使路面路基结构的竖向压应力和沉降变形增大。同样，在非浸水(土层含水量基本一致)的情况下，压实密度降低也会使路面路基结构的竖向压力和沉降变形增大。比较水的浸入(土层含水量增大)和压实密度降低(降低约5％)两种因数对路面路基结构应力和变形特性的影响程度可发现，水的浸入(土层含水量增大)对路面路基结构应力和变形的影响要大于压实密度降低(降低约5％)对路面路基结构的影响。水的浸入和碾压质量不高是造成路面早期破坏的因数之一。更多还原

【Abstract】 Road transportation plays an important role in the economy all around the world. With the need of heavy load,dense flow rate and high speed,the higher quality of the road structure is demanded. Research results show that the settlements of the road structure mainly come from the consolidation and the accumulative residue settlements under the cyclic loads. Excessive uneven settlements will produce the premature failure on the pavement. And few researches on the interaction of pavement and subgrade have been developed at present. So it is necessary to do a large-scale model experiment in order to research the dynamic response of the pavement and subgrade under traffic loads.This thesis presents a research program on pavement and subgrade structure in the second phase of Guangbei Section of National Highway 108 (Beijing to Kunming). A full-scale model experiment that according to the constructions of Guangbei Section of National Highway 108 has been carried out in laboratory. Sandbag is used to make a flexible wall around the model in order to make the condition of the experiment more closely to the true condition. Through the static and standard traffic cyclic loads,the responses of the pavement and subgrade have been attained. The studies on these responses such as elastic deformations,accumulative settlements and stress have been made under the changed characters of subgrade,such as moisture content,relative compaction of subgrade.The results of the experiments show that superfluous moisture content increases the vertical stress and the settlements of the construction under the similar relative compaction. And under the similar moisture content,lower relative compaction increases the vertical stress and the settlements of the construction either. Comparing the influence to the construction under the changing of these two facts,we can find that the changing of moisture content effects the construction more than the changing relative compaction does. So the immerging of the water and the low quality of the compaction are the reasons on the premature failure of the pavement.更多还原