|
With the on-site measured pavement temperature from some section on Jing-Zhu expressway, the rule of maximum tensile stress, maximum shear stress and the maximum flexure of surface at different slope and different stress field were presented by FEM, under the composite effect of horizontal loading and vertical load. It turns out that the degree of slope affects the stress of surface course more, and the tensile stress appears within the range of 2cm-deep from surface. The high temperature field did not make tensile stress and shear stress of upslope pavement increase, but it made the flexure of surface rise. Then efforts were made in this study to investigate rutting failures on Jing-Zhu expressway in China, a long and steep slope expressway, to determine the cause and the source of the rutting. The features of the rutting on each asphalt pavement layer were analyzed by surveying the rutting depth, excavating transverse profile section, and boring samples in the typical sections of expressways where different degree of rutting damages were observed. It was found that 60% of rutting is generated by asphalt middle course and the remaining 40% comes from the other surfaces, which means that middle course is the most important surface course to resist rutting disease. Finally, according to the results, some suggestion for the design of the upslope pavement structure was put forward. According to it, the mixture of the surface was designed and test road was built. The detected data from the test road turns out the asphalt pavement has a good performance. |
|
Keywords:road engineer;asphalt pavement;FEM;Upslope;rutting |
|