基于粘弹塑性理论的沥青路面车辙分析

Analysis of Asphalt Pavement Rut Based on Elastic-viscoplastic Theory

应用粘弹塑性理论，研究了沥青混合料一维粘弹塑性本构关系，并运用ABAQU软件建立了柔性基层沥青路面车辙分析的有限元模型，研究了路面车辙的发展规律，经环道试验进行了验证。结果表明：荷载作用初期路面车辙发展较快，而后期车辙发展较慢；路面永久变形主要由绝对车辙引起，侧向隆起仅占15％～30％；随着沥青层厚度增加，车辙增加，但增加幅度逐渐减小；从表层开始沥青层的变形率随深度的增加而逐渐变大，在8cm处变形率达到最大值，之后逐渐减小；沥青路面车辙主要产生在结构深度20cm深度范围以内，尤其在4～12cm之间。另外，进行了重载作用下的路面车辙模拟，对基于车辙等效的轴载换算进行了探讨，提出轴载换算系数为5．9。

The elastic-viscoplastic theory is applied to research the permanent deformation of asphalt mixture, and a creep model was adopted for its good agreement with actual result. ABAQUS, the finite element modeling technique, are employed to simulate and investigate rut of the asphalt pavements with flexible base, and then the results are validated according to the circular track test. It is indicated that, rut increases fast in the early stage, but slow in later stage; pavement rut consists chiefly of absolute rut, and lateral upheaval only accounts for 15% - 30% ; deformation rate increases as the depth increases and achieves the largest value at the depth of 8 cm, then it decreases gradually; pavement absolute rut is composed primarily of rut in the layer within the depths of 4 cm and 20 cm, especially within the depths of 4 cm and 12 cm. In addition, pavement ruts are simulated under different loads, and the axle load conversion indices are obtained by the rut equivalent method. For the adopted structures, the indices is 5.9.