半刚性基层沥青路面-路基协调设计

The Pavement-Subgrade Coordinate Design of Asphalt Pavement with Semi-Rigid Base

基于大型通用有限元软件ABAQUS,建立两种典型半刚性基层沥青路面结构的三维有限元模型,针对3种路基高度和4种路基回弹模量,计算半波正弦荷载作用下路面结构的动态响应,结合半刚性路面各结构层疲劳寿命预估方程,分析路面结构疲劳寿命随路基回弹模量变化的规律和相互协调问题。结合交通等级标准,确定满足不同交通等级的临界路基模量。分析表明:路基模量对沥青层疲劳寿命影响较小,对半刚性基层和永久变形预估寿命影响较大;路基高度对半刚性基层路面各结构层疲劳寿命的影响均较小,尤其是对沥青层疲劳寿命影响更小;具有柔性底基层的半刚性路面结构的临界路基模量比具有半刚性底基层的路面结构大。

Based on the large general-purposed finite element software ABAQUS, the two typical kinds of 3D finite element models of asphalt pavement structures with the semi-rigid base are established. Aiming at three kinds of subgrade heights and four kinds of subgrade moduli, the dynamic responses of pavement structures under the half-sine wave loads are calculated. Combined with the prediction equation of the fatigue life of all structures with the semi-rigid base, the regularity and the coordination of the fatigue life of pavement structures following the variation of resilient subgrade moduli are analyzed. Furthermore, the critical subgrade moduli which meet different traffic levels are determined according to the standards of the traffic levels. The analyses indicate as follows. The subgrade modulus has a weak effect on the fatigue life of asphalt layers and a greater impact on the fatigue life of the semi-rigid base and permanent deformation. The subgrade height has less influence on the fatigue life of all structural layers of the semi-rigid base, especially the fatigue life of asphalt layers. The critical subgrade modulus of the flexible semi-rigid base structure is bigger than that of the pavement structure with the semi-rigid base.