Development of the Texas Flexible Pavements Database.

摘要

The goal of this research project was the development of the Texas Flexible Pavement Database (TFPD) to serve as a reference database comprising design, construction, structural and performance data for selected roadway sections in Texas. The database was designed as a project-level application with the purpose of developing, validating and calibrating mechanistic-empirical pavement design models. To achieve this objective it was necessary to evaluate pavement sections with performance data spanning a number of years and for this reason the database was initially populated with Texas sections from the Long Term Pavement Performance (LTPP) studies. In addition, a number of newly constructed sections within Texas were included in the database. The performances of these new sections were monitored over a two-year period and performance data collected on these sections on two occasions have been included in the database. The TFPD comprises 70 sections (35 from LTPP and 35 new) spanning the climate, traffic, and structure types found in Texas. It is recommended that these sections continue to be monitored on an annual basis to track the performance of these pavements throughout their design life. It should be noted that the entire database consist of close to 200 sections, though few of them are missing information related to material properties and testing. A second objective of this project was to provide guidelines for local calibration of the Mechanistic Empirical Pavement Design Guide (MEPDG). The performance models used in the MEPDG are calibrated using sections spread throughout the U.S. Hence, it is necessary to calibrate these models for specific states and regional conditions because of the differences in terms of materials, environmental conditions, and construction practices. The regional calibration factors were obtained by minimizing the sum of squared errors between the observed and the predicted distresses. In this case, a simultaneous joint optimization routine was used because it is theoretically sound. Finally, an average of the regional calibration coefficients for AC and subgrade rutting was computed to obtain the set of state-default calibration coefficients for Texas. The report outlines the procedure followed and reports the initial local and statewide calibration factors determined based on the LTPP sections currently in the TFPD.