柔性基层沥青路面结构粘弹性三维有限元分析

Analysis of asphalt pavements with flexible base using viscoelastic three-dimensional finite element method

以沈大高速公路沈鞍段路面结构为例,在温度变化时考虑沥青混合料粘弹性影响,建立了柔性基层沥青路面温度场疲劳断裂模型,借用三维有限元实现交通荷载及温度荷载耦合作用下路面结构的动力特性。研究多场耦合作用下柔性基层沥青路面结构的破坏行为。研究表明:荷载在移动过程中剪切型应力强度因子对路面开裂起控制作用;降温时张开型应力强度因子是沥青路面开裂破坏的主要因素;对柔性基层沥青路面结构考虑变温和交通荷载耦合作用下的疲劳寿命预估,结果显示,该方法与实际更为接近。

Taking the pavement structure of Shen-An period in Shen-Da highway as the example and considering the asphalt mixture viscoelasticity when temperature changed, the fatigue fracture model of flexible base asphalt pavement in temperature field was established. Then using the three dimensional finite element technology, the dynamic properties of the pavement structure under the coupling action of the traffic and temperature load were achieved and the destructive action of flexible base asphalt pavement was also analyzed under the action of multiple field coupling. The study showed that in the process of pavement cracking, the shear stress intensity factor played a control role as the load moved and the opening mode stress intensity factor was the critical role as the temperature felled. Predicting the fatigue life of flexible base asphalt pavement by considering the coupling action of the traffic and temperature load, the result showed this method was almost completely approaching the reality.