Modelling of Pavement Response From a Field Test

Abstract

Modelling of pavement response is central in mechanistic pavement analysis and the validity of response models is hence an important prerequisite for reliable evaluation of structural pavement condition. With the objective of verifying predicted pavement response, an instrumented field test pavement was established on top of a sandy material sufficiently thick to be considered a halfspace. Later a layered flexible pavement system was constructed on top of the halfspace. Falling Weight Deflectometer (FWD) loads were applied at each layer of the pavement to provide input to built-in instruments, which registered stress and strain in three orthogonal directions in the sandy subgrade. At each pavement layer additional FWD measurements were carried out at several locations to determine elastic layer moduli. Based on layer moduli, pavement response was predicted using response methods ranging from a simple Boussinesq mod el to finite element methods. Comparison between the predicted and observed pavement response showed very good agreement for strain response
while the agreement was more questionable for stress. The paper shows that although it was difficult to establish a completely homogeneous test field, several response models reliably predicted strain response in a halfspace, while a three-dimensional finite element program considering the dynamic load situation performed best in the prediction of response in a multilayer pavement system.