针对沥青路面结构层位与其设计寿命的匹配性问题,分析了在用公路沥青路面面层与基层的破坏先后顺序及其原因,推导得到了基于现设计指标弯沉与层底拉应力的沥青路面结构层疲劳寿命计算公式。以我国高速公路半刚性基层沥青路面典型结构为例,计算获得了各结构层顶面的弯沉和层底拉应力,据此反算了各结构层的疲劳寿命。研究发现,按现规范的等寿命设计思想设计出的沥青路面结构,无论是其实际寿命或是计算出的各结构层疲劳寿命,均呈现出较大的差异性,基层的疲劳寿命远远高于面层的疲劳寿命,表明沥青路面结构层层位与其设计寿命存在着不匹配性。因此,采用疲劳寿命逐层递增的方法进行耐久性沥青路面各结构层寿命组合设计是必要的,也是可行的。
In view of the matching problem of layer position and its design life, the failure sequence and its reason were analyzed for the base course and surface course of the highway asphalt pavement. Based on the current design indexes deflection and tensile stress in the bottom layer, the calculation formula of fatigue life was deduced for the asphalt pavement structure layer. The typical structure of expressway semi-rigid base asphalt pavement in China being taken as an example, the deflection and tensile stress in the bottom layer of typical structure were calculated. Then, the fatigue life of each structural layer was calculated. According to the current equal life design specification, the study presents a large difference of each structure layer life whether the real life or the calculated fatigue life. The fatigue life of the base course is much larger than the surface course one. It indicates that there exits matching between the structure layer position and design life. It is necessary and feasible to adopt life combination design for using the fatigue life increment method of structure layers to the durable asphalt pavement.