Impact of dynamic loading on pavement deflection measurements from traffic speed deflectometer.

• Analyzed dynamic loadingimpact on traffic speed deflectometer (TSD) measurement. • Developed semi-analytical finite element model for dynamic loading on pavement. • Studied the relationship between dynamic loads and deflection measurements. • Quantified effect of pavement roughness on measurement error using AUTC method. Traffic speed deflectometer (TSD) provides an efficient way for evaluating pavement condition. The current principle is to convert measured deflection slopes into the deflection basin using the Area Under The Curve (AUTC) method based on the time-space transform and elastic material theory. This study aims to investigate impact of dynamic loading due to pavement roughness on TSD measurements. Semi-analytical finite element (SAFEM) method was developed to simulate dynamic moving loads on flexible pavements with viscoelastic asphalt layer. The variations of pavement deflection and deflection velocity were found increasing linearly with dynamic loading coefficient (DLC), especially for deflection velocity. The average relative error between the actual deflection basin and the one from the AUTC method could be 15% at DLC of 0.1 with the highest error for the maximum deflection. This indicates the necessity of developing correction method of TSD deflection measurements on rough pavements. [ABSTRACT FROM AUTHOR]