Due to time-temperature dependent behavior of asphalt concrete (AC), viscoelastic analysis is necessary for understanding the mechanism of top-down cracking (TDC). In this study, a new approach for determining the viscoelastic surface responses of multi-layered asphalt pavements was developed to solve the complicated oscillating behavior and slow convergence of the integrand of Laplace-transformed step-response function at pavement surface. By employing the Lucas algorithm, the irregular oscillations were reduced to regular oscillations by separating the integrand into high- and low-frequency components. The results calculated from the proposed approach were widely verified against finite element (FE) results. According to horizontal strains calculated at pavement surface, mechanism of TDC initiation was investigated under stationary and moving loads. The results indicated that high temperature and low vehicle speed were among the predominant factors contributing to TDC initiation. In addition, TDCs were more likely to initiate at a very close distance to the tire edge.

由于沥青混凝土 (AC) 的随时间变化的行为，粘弹性分析对于理解自上而下开裂 (TDC) 的机制是必要的。本研究针对多层沥青路面粘弹性表面响应的确定方法, 解决了路面拉普拉斯变换阶跃响应函数被积函数复杂的振荡行为和收敛缓慢的问题。通过使用 Lucas 算法，通过将被积函数分离为高频和低频分量，将不规则振荡减少为规则振荡。从所提出的方法计算的结果已针对有限元 (FE) 结果进行了广泛验证。根据路面水平应变计算，在静止和移动载荷下研究了 TDC 启动机制。结果表明，高温和低车速是导致 TDC 启动的主要因素。此外，TDC 更有可能在距轮胎边缘非常近的距离处开始。