Calibrating Mechanistic-Empirical Design Guide Permanent Deformation Models Based on Accelerated Pavement Testing

    Volume 37, Issue 1 (January 2009)

    ISSN: 0090-3973

    CODEN: JTEOAD

    Published Online: 13 November 2008

    Page Count: 9


    Hong, Feng
    Pavement Engineering Specialist, Texas Department of Transportation, Austin, TX

    Chen, Dar-Hao
    P.E., Pavement Engineering Supervisor, Texas Department of Transportation, Austin, TX

    (Received 1 May 2008; accepted 10 October 2008)

    Abstract

    One of the challenges to the implementation of the mechanistic-empirical pavement design guide (MEPDG) comes from calibrating the transfer functions. This paper focuses on calibration of one of the major distress models in flexible pavement: permanent deformation or rutting. Two key aspects are critical to a successful rutting model calibration: data and method. Regarding the data, existing in-field information only provides total rut depth, which could not meet the requirement of permanent deformation in each structural layer by the MEPDG. Concerning the method, existing work either fails to address calibration factors from a holistic perspective by only focusing on individual sections separately or ignores variability inherent in those factors. In this study, layer-wise permanent deformation from instrumented pavement under accelerated pavement testing serves to accommodate the models calibration. A systematic calibration procedure is established, which globally optimizes all available information across all test sections. Through simulation and numerical optimization, optimal calibration shift factors for three typical flexible pavement materials, asphalt mixture, unbound granular base, and finegrain soil are obtained as 0.60, 0.49, and 0.84, respectively. This implies that the uncalibrated MEPDG is biased toward overprediction of rut depth. It is further suggested that a more rational result for each calibrated factor is to introduce an appropriate distribution to characterize its uncaptured variability. In addition, a case study involving using calibrated MEPDG to predict pavement performance or life indicates that (1) model calibration has a significant impact on the prediction and (2) the “fourth power law” is supported by the MEPDG.


    Paper ID: JTE101854

    DOI: 10.1520/JTE101854

    ASTM International is a member of CrossRef.

    Author
    Title Calibrating Mechanistic-Empirical Design Guide Permanent Deformation Models Based on Accelerated Pavement Testing
    Symposium , 0000-00-00
    Committee E17