Load spatial superposition effect in Traffic Speed Deflectometer tests of pavements

Abstract

Devices that can evaluate the structural health of pavements at traffic speeds, such as the Traffic Speed Deflectometer (TSD), have become increasingly popular because of their high measuring efficiency. Concurrently, there has been a growing body of research focused on the theoretical understanding and practical application of the TSD test. However, few studies have considered the load spatial superposition effect when conducting theoretical modelling of the TSD test, which introduces errors in the parameter identification process. Hence, this study investigated the effect of load spatial superposition on pavement response during the TSD test using a self-developed software called PaveMove. The results showed that, for pavements with flexible base, the TSD deflection-based parameter identification requires the consideration of the whole TSD load, while the TSD slope-based parameter identification has more degrees of freedom in the choice of load patterns. In contrast, for pavements with (semi-)rigid base, both the TSD deflection- and slope-based parameter identifications require the consideration of the whole TSD load. The presented work paves the way to develop more accurate parameter identification techniques for the TSD test, which ultimately contributes to more effective management of road networks.