The modulus gradient of asphalt concrete (AC) layers is an important feature of flexible pavements. The variation of the modulus with depth results from the synthetical effect of material properties, the service time of pavements, loading and environmental conditions. Since the modulus gradient directly affects critical responses and performance of pavements, the determination of the modulus gradient of AC layers is necessary for the evaluation, maintenance and rehabilitation of flexible pavements. This paper aims to propose a method to obtain layer moduli of flexible pavements at different loading frequencies, which include a power function describing the modulus gradient of AC layers. The method utilizes results from a typical nondestructive test in the field applying the falling weight deflectometer and techniques of the fast Fourier transform, finite element model updating, kriging model and artificial intelligence. The method is validated by comparing layer moduli obtained from the proposed method and other backcalculation softwares.

中文翻译：

---

使用落锤挠度计和人工智能确定柔性路面的复模量梯度

沥青混凝土（AC）层的模量梯度是柔性路面的一个重要特征。模量随深度的变化是材料特性、路面使用时间、荷载和环境条件的综合影响的结果。由于模量梯度直接影响路面的临界响应和性能，因此确定AC层的模量梯度对于柔性路面的评估、维护和修复是必要的。本文旨在提出一种在不同加载频率下获得柔性路面层模量的方法，其中包括描述 AC 层模量梯度的幂函数。该方法利用了现场应用落锤挠度计和快速傅立叶变换技术的典型无损测试的结果，有限元模型更新、克里金模型和人工智能。通过比较从所提出的方法和其他反计算软件中获得的层模量来验证该方法。