TSD Deflection Bowl Simulation and Correlation between TSD data & AASHTOWare Pavement ME Design

Abstract: Traffic Speed Deflectometer (TSD) technology has been gaining traction in pavement design and management practices for more than ten years. TSD can continuously collect deflection data at traffic speed without requiring traffic control like conventional pavement deflection measuring devices such as Falling Weight Deflectometer (FWD). TSDs can operate at a traffic speed up to 60 mph without any traffic disruption.The TSD measures deflection velocities rather than deflections. The measured deflection velocity depends on the driving speed. To remove this dependence, the deflection velocity is divided by the instantaneous vehicle speed to obtain the deflection slope. The deflection values with be then calculated from integration of the deflection slope measures. Many states have been collecting and using TSD data to estimate the structural condition of their flexible pavements. In this study, the deflection bowl generated from the TSD data has been simulated using the 3D-Move and DSteele Software. A theoretical parametric study was also conducted to simulate TSD loading. Furthermore, a synthetic pavement database (243 pavement sections) was created using the developed 3D-Move models and the pavement sections was run using the AASHTOWare Pavement ME Design (PMED) software. The predicted pavement distresses (IRI, cracking) showed a good correlation with the deflection basin parameters.