Implementation and local calibration of the MEPDG transfer functions in Wyoming.

PDFTech ReportFHWA 16/02FRS03209Mechanistic-empirical pavement designImplementationCalibrationFatigue crackingRuttingTransfer functionsTest sectionsField testsPavement performanceRigid pavementsFlexible pavementsWyomingWyoming. Dept. of TransportationBhattacharya, Biplab B.Von Quintus, Harold L.Darter, Michael I.Applied Research Associates, Inc.United States. Federal Highway AdministrationUS Transportation CollectionThe Wyoming Department of Transportation (WYDOT) currently uses the empirical AASHTO Design for Design ofPavement Structures as their standard pavement design procedure. WYDOT plans to transition to the MechanisticEmpirical Pavement Design Guide (MEPDG) for designing new and rehabilitated highway pavements. As a part of thetransitioning process, WYDOT has sponsored an implementation project. One part of the implementation project is toverify the MEPDG global distress transfer functions and calibrate these functions to local conditions, if determined tobe necessary. The Wyoming Long-Term Pavement Performance (LTPP) and non-LTPP roadway segments, as well asLTPP test section is adjacent states were used for this verification-calibration process.As noted above, one objective of the implementation project was to verify or confirm that the MEPDG transferfunctions and global calibration coefficients derived from NCHRP project 1-40D reasonably predict distresses andsmoothness in Wyoming. One of the tasks within this project focused on using the Wyoming LTPP test sections toconfirm the applicability of the global calibration coefficients. Results from the initial verification concluded some ofthe transfer functions exhibited significant bias between the measured and predicted distress and require localcalibration. Thus, some of the LTPP test sections in adjacent states with similar design features built in Wyomingcombined with some non-LTPP roadway segments in Wyoming were used to determine the coefficients of the transferfunctions to eliminate any bias between the measured and predicted distresses.This report documents the local calibration of the transfer functions using LTPP and non-LTPP roadway segments. Thecalibration process follows the steps presented in the 2010 AASHTO MEPDG Local Calibration Guide. Localcalibration coefficients were derived to remove that bias for the rutting, fatigue cracking, and thermal cracking transferfunctions of flexible pavements, and the faulting and fatigue cracking transfer functions of rigid pavements. The globalcoefficients of the smoothness degradation regression equation for flexible and rigid pavements were also checked fortheir applicability to Wyoming conditions