基于车辙等效的沥青路面轴载换算方法

Conversion Method of Axle Load for Asphalt Pavements Based on the Rutting Equivalent

以剪切应力强度比为指标建立了基于车辙等效的沥青路面轴载换算方法。通过有限元路面力学和温度场模型对典型高等级沥青路面结构进行分析,得到不同环境和荷载条件下的轴载换算指数,通过多元线性回归得到其预估公式,并通过实例计算结果与现行规范方法的进行了比较。研究表明:面层厚度、层位、混合料类型、温度和车速条件都对轴载换算指数有着显著的影响;沥青混合料剪切应力强度比与抗车辙性能之间的良好的相关性并不依赖于材料类型、温度、荷载和围压水平;基于不同控制指标的轴载换算结果相差较大,本文提出的基于车辙等效的换算方法可以作为现行规范方法的有益补充。另外,认为进行轴载换算时对于不同沥青层位应该分别计算。

The conversion method of axle load was proposed for asphalt pavements based on the rutting equivalent using the ratio of shear stress to strength as an indicator. The typical pavement structures were analyzed using a finite element model. The conversion exponent nwas calculated for different environmental and loading conditions. The nequation was obtained using a multiple linear regression. Finally, the proposed method was compared with the current specifications. It is found that the asphalt layer thickness, asphalt layer location, mix type, temperature and traffic speed have significant effects on the conversion exponent n. Also, it was observed that the ratio of shear stress to strength was nicely correlated with the rutting performance. It did not depend on the mix type, stress and temperature levels. The proposed method could be used as the useful supplement to the current specifications. The conversion exponent nshould be individually calculated for each asphalt layer.