The measurement of pavement surface deflections under moving loads can be used for evaluation of pavement structural condition. The objective of this paper is to develop an innovative backcalculation method to calculate pavement layer moduli based on traffic speed deflectometer (TSD) measurements and analyze factors influencing backcalculation results. The backcalculation method is based on 2.5D finite element method (FEM) and constrained extended Kalman filter (CEKF). Field measurements at different pavement sections were used to verify the accuracy of backcalculation results. Parametric analysis was conducted to evaluate the influences of traffic loading and pavement structure variations in the field. It was found that the backcalculation results were considerably affected by the variation of asphalt layer thickness and dynamic loading due to pavement surface roughness. A heavy truck passing the adjacent lane during TSD testing could also cause variation of backcalculation results.

中文翻译：

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在移动载荷下使用表面挠度对沥青路面模量进行反算

在移动载荷下的路面挠度的测量可用于评估路面结构状况。本文的目的是开发一种创新的反计算方法，该方法基于交通速度偏转仪（TSD）的测量来计算路面层模量，并分析影响反计算结果的因素。反算方法基于2.5D有限元方法（FEM）和约束扩展卡尔曼滤波器（CEKF）。使用不同路面部分的现场测量结果来验证反算结果的准确性。进行了参数分析，以评估现场交通负荷和路面结构变化的影响。结果发现，由于路面表面粗糙度，沥青层厚度和动态荷载的变化会大大影响反算结果。在TSD测试期间，一辆重型卡车通过相邻车道也会导致反算结果的变化。