Whereas all stresses and strains calculated with the linearĮlastic theory are outside of the range of measured stresses andĪbstract = 'Backcalculation of FWD data often results in unrealistic moduli. In stresses and strains within the range of measured values, For thisĮxample it is found that the best agreement between measured andĬalculated stresses and strains is obtained with MET. Three methods are also compared to measured values. The paper includes anĮxample where moduli backcalculated using FEM, linear elastic (MET), modified for a nonlinear subgrade. Simpler approach is to use the Method of Equivalent Thicknesses Stresses and strains.The response of nonlinear elastic materialsĬan be calculated using the Finite Element Method (FEM). This paper demonstrates, that treating the subgrade asĪ nonlinear elastic material, can result in more realistic moduliĪnd a much better agreement between measured and calculated Models assume that all pavement layers consist of linear elastic Respect to reality and must be verified experimentally. Pavement response are based on a number of simplifications with In the pavement are compared with theoretical values, theĪgreement is often poor.All theoretical models for calculating Value, and the modulus of an intermediate granular material may be The modulus of the subgrade may be two to three times the expected Backcalculation of FWD data often results in unrealistic moduli.

Backcalculation fwd on subgrade