Numerical Analysis to Evaluate Sensitivity of Traffic Speed Deflection Devices to the Structural and Material Properties of Flexible Pavements

Abstract

Structural evaluation of pavement is crucial for informed maintenance and rehabilitation decisions within pavement management systems. Traffic speed deflection devices (TSDDs) can be used as practical tools to support these activities expeditiously. The effectiveness of TSDD data in pavement management depends on a thorough understanding of the complex interplay between pavement properties, environmental conditions, and the deflection parameters captured. Material attributes such as layer thickness and composition, alongside operational factors such as temperature and vehicle speed, may significantly influence pavement deflection parameters. In this study, more than 100,000 simulated pavement structures were analyzed using viscoelastic numerical modeling and statistical analysis techniques to decipher the intricate relationship between pavement characteristics and TSDD-measured deflections or deflection slopes. The subgrade modulus is the primary factor influencing the deflection/slope parameters of TSDDs. Operational parameters, including vehicle speed and tire pressure, are marginally correlated with the TSDDs’ deflections/slopes as long as they are controlled reasonably well during data collection. The predictive power of more than 40 deflection-based indices was evaluated to identify the most effective index for isolating the layers of concern within a pavement structure. This research contributes to the optimization of TSDDs’ practical applications in pavement evaluation for more effective management and preservation of pavement infrastructure.