Effect of the input of structural parameters’ uncertainties and analysts’ arbitrary decisions on the results of backcalculated pavement materials’ resilient moduli

This study examines how uncertainties in the input of structural parameters and analysts’ decisions affect the estimated resilient moduli of pavement layers obtained through backcalculation. Three structures with varying asphalt layer thicknesses were created to predict deflectometric basins, using the falling weight deflectometer (FWD). Backcalculations were then performed with variations in layer thicknesses (within the 5% range), Poisson’s ratio of each layer, and seed moduli of each layer. This was repeated 60 times for each structure with randomized parameter variations. Resilient moduli from backcalculations were compared to reference structures, revealing relative errors. Statistical analysis showed uncertainties in layer thicknesses and that Poisson’s ratios impact backcalculation results by 3%–33%, depending on asphalt layer thickness. This variability could alter conclusions in pavement assessment. This is a case study with real deflectometric basins validated theoretical findings using field data.