Dynamic analyses of traffic speed deflection devices

Abstract

Two traffic speed deflection devices (TSDDs) that measure surface deflections at posted traffic speeds (up to 80–96 kph) were evaluated through a recent Federal Highway Administration project that included field trials at the MnROAD facility. Four geophones were embedded near the pavement surface to measure surface deflections during field trials at each of three MnROAD cells. In addition, the MnROAD facility counted with numerous other sensors such as strain gauges to measure pavement responses and thermocouple trees to collect pavement temperature at various depths. For the implementation of TSDDs in any network-level pavement management system, it is important to utilise a proper analytical model that can accommodate moving load and viscoelastic properties of pavement layers in the simulation of TSDD measurements. The 3D-Move software was chosen for this purpose. The viscoelastic properties used for the asphalt concrete (AC) layer include dynamic modulus and damping coefficient as a function of frequency relevant to the temperature at the time of the MnROAD field trials. The field trials and available data represented realistic field case scenarios to validate once more 3D-Move specifically for TSDD measurements. The proposed dynamic analytical model provided a good match with a variety of independent pavement responses that included surface deflection bowls (measured using embedded geophone sensors) as well as horizontal strains at the bottom of the AC layers (measured using MnROAD sensors).

Keywords:

• Traffic speed deflection
• dynamic simulation
• surface deflections
• pavement response
• field evaluation

Acknowledgements

This study was funded through the FHWA study DTFH61-12-C-00031 and the support is gratefully acknowledged. The authors would like to thank Dr Nadarajah Sivaneswaran of the FHWA and Dr Senthil Thyagarajan of ESC, Inc. for their kind support. The authors greatly acknowledge Dr Elie Hajj for his valuable advices. The authors would also like to thank Mr Ben Worel and the rest of the MnROAD staff without whose help, the successful outcome of the project would not have been possible. The conclusions presented in this paper are solely those of these authors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

This work was supported by Federal Highway Administration [grant number DTFH61-12-C-00031].

Additional information

Funding

This work was supported by the Federal Highway Administration [grant number DTFH61-12-C-00031].