Abstract
A time domain backcalculation program is developed, and it is used to predict the response of the FWD test from LTPP test sections for three-layer and four-layer pavements. The Newmark scheme is used for the time integration, and the pattern search approach of optimization is adopted to perform the backcalculation analysis. First, the backcalculations based on the synthetic data generated by the finite element program show a good agreement between the backcalculated and given material properties. Then, the backcalculation is performed to analyze the FWD data of three-layer and four-layer pavements from the LTPP database; the predicted and measured history responses deflection are close. Finally, the backcalculated properties are used to predict the dynamic response of the FWD test in which the deflection data was not used for backcalculation analysis; the results show that the predictions and the test results agree very well.
