A STRUCTURAL EVALUATION METHODOLOGY FOR PAVEMENTS BASED ON DYNAMIC DEFLECTIONS. INTERIM REPORT

A framework for structural evaluation of pavements based on dynamic deflections is presented. A self-iterative procedure has been developed to estimate insitu Young's moduli of pavement layers by using the approach of inverse application of layered elastic theory (ELSYM5) to obtain the best fit of a measured deflection basin. For asphalt pavements, a temperature correction procedure is presented for the asphaltic concrete moduli. Nonlinear strain-softening models are introduced and discussed to take into account nonlinear behavior of granular layers and subgrade. A self-iterative procedure has been developed to estimate nonlinear strain-softening moduli of these layers from Dynaflect deflection basins based on the concepts of equivalent linear analysis. An indication of the structural capacity of existing pavement is obtained from the remaining life analysis. Computer programs RPEDD1 (for rigid pavement) and FPEDD1 (for flexible pavements) are developed to evaluate dynamic deflection basins measured by the Falling Weight Deflectometer and Dynaflect. Guidelines are presented for applications and implementation of these computer programs, especially in rehabilitation design.