The subgrade in the finite element model was formulated with springs of stiffness coefficient of subgrade and dashpots of the derived damping values. The key points in the finite element simulationof FWD tests were studied including model size, boundary conditions, andanalysis time increment. A reliablesimulation model is helpfulto calibrate the apparatus as well as the backcalculation programs. Backcalculation programs without subgrade damping may over-predict structural condition of pavements.ĪB - The falling weight deflectometer (FWD) producespavement responses by a falling massdrop to evaluate structural parameters of the pavement. Subgrade damping plays an important role in simulations of the FWD test. A rigorous procedureis presented to derive subgrade reaction and damping for various types of subgrade soil. It was concluded that at least sixtimes the radius of relative stiffness is required to avoid boundary cut-off error. N2 - The falling weight deflectometer (FWD) producespavement responses by a falling massdrop to evaluate structural parameters of the pavement.
![backcalculation fwd on subgrade backcalculation fwd on subgrade](https://www.frontiersin.org/files/Articles/327695/fnhum-12-00189-HTML/image_m/fnhum-12-00189-g005.jpg)
T1 - Significance of subgrade damping on vehicle-pavement interactions