基于叠加原理的沥青路面永久变形预估方法

Permanent Deformation Prediction Method of Asphalt Pavement Based on Superposition Principle

分析了沥青路面产生永久变形的主要影响因素,采用"分层分区叠加思想",建立了考虑车辆重复荷载、路面材料特性及温度条件等因素综合作用的沥青路面永久变形预估方法,研究了预估模型中参数的确定方法。推导了重复荷载作用下沥青混合料的黏弹性本构模型,结合三轴重复加载试验数据研究了沥青路面各结构亚层沥青混凝土的蠕变柔量的拟合方法;通过对试验路温度进行实测,确定了年各代表温度区间内标准轴载作用次数;采用有限元方法分析了不同温度条件下沥青路面结构各亚层偏应力分布;最后运用该预估方法对綦万高速公路沥青路面的永久变形量进行了计算。结果表明:计算值和实测值基本吻合,建立的预估方法具有较高的计算精度,能够较精确地模拟沥青路面的变形规律。

The main factors caused asphalt pavement permanent deformation were analyzed. Fully considered the repeated vehicle loads, the pavement material properties and the temperature conditions, a prediction method of asphalt pavement permanent deformation was established based on the hierarchical and regional superposition principle, and the acquisition method of corresponding model parameters was researched. The viscoelastic constitutive model of asphalt mixture under repeated loads was obtained. Combined with the test data of triaxial repeated load, the creep compliance fitting method of structure sub-layer of asphalt pavement was studied. By the actual measurement of test road, the representative year temperature intervals and the corresponding times of standard axial load were obtained. By using the finite element method, the deviatoric stress distributions of structure sub-layer of asphalt pavement under different temperature conditions were an- alyzed. Finally, the permanent deformation of asphalt pavement of Qijiang-Wanzhou expressway was calculated with the es- tablished prediction method. The results show that the calculation values have a good consistency with the measured values and the prediction method has higher calculation accuracy. It can more accurately simulate the deformation law of asphalt pavement.