Impact of Spatial Subgrade Variability on the Mechanistic-Empirical Pavement Design
摘要
The AASHTOWare Pavement Mechanistic-Empirical Design (PMED) software is based on mechanistic response algorithms, and empirical relationships where measurable surface distresses are related to the mechanistic responses for pavement design analysis. PMED uses the soil resilient modulus to characterize the subgrade layer and recommends providing a resilient modulus of at least 69 MPa. This research studied six projects to assess subgrade characteristics using a Falling Weight Deflectometer and a Dynamic Cone Penetrometer. Resilient moduli were back-calculated from the FWD data and also calculated from a correlation with the Dynamic Cone Penetrometer results. The effect of subgrade characterization on PMED design analysis was then assessed using these subgrade resilient moduli. Recommendations were made regarding the selection of design subgrade resilient modulus.