为了给沥青路面结构的分析和设计提供参考,利用三维有限元方法对典型沥青路面结构的力学响应进行了分析,分析中分别将沥青混合料当作粘弹性材料和以动态模量、抗压回弹模量表征其基本力学参数的弹性材料。分析了不同温度、行车速度及基层类型下路表弯沉、沥青面层底和半刚性基层底水平应力,并对结果进行了比较。结果表明:基于动态模量的分析和粘弹性分析结果比较接近,尤其是路表弯沉峰值和半刚性基层底水平应力峰值的平均相对误差在2%以内;而采用抗压回弹模量分析的结果则差别较大,尤其是沥青面层底拉应力峰值只有粘弹性分析结果的1/3左右;在弹性分析范畴内,应该用动态模量取代抗压回弹模量,以提高路面力学响应分析结果的精度并综合考虑温度、行车速度等因素的影响。
In order to provide reference for the analysis and design of asphalt pavement, pavement responses of typical asphalt pavement structures were analyzed using three-dimensional finite element method. Asphalt mixtures were treated as viscoelastic materials and elastic materials whose mechanical properties were represented by dynamic modulus and compressive resilient modulus. Surface deflections, horizontal stresses at the bottom of asphalt layer and semi-rigid base were calculated at various temperatures and vehicle speeds for different base types. The results show that pavement responses obtained through dynamic modulus are close to those through viscoelastic analysis, especially the average relative errors of the peak values of surface deflection and horizontal stress at the bottom of semi-rigid base are within 2~/oo. The results through compressive resilient modulus are significantly different, especially the peak value of horizontal stress at the bottom of asphalt layer is only one-third of that through viscoelastic analysis. Dynamic modulus, instead of compressive resilient modulus, should be used in elastic analysis of asphalt pavement structure in order to achieve accurate results and the effects of temperature and vehicle speed should also be taken into account.