Use of Pasternak Foundation Model in Concrete Pavement Analysis

Abstract

This paper examines the use of Pasternak foundation model in the analysis of load-induced concrete pavement deflections and bending stresses, as well as thermal stresses caused by warping of slabs. Using theoretical solutions developed by the authors for structural responses of slabs supported on Pasternak foundation, predicted slab deflections and bending stresses are computed and checked against actual field data. The field data, containing pavement responses under applied loads and thermal gradients respectively, are obtained from the results of full-size slab experiments reported in the literature. Satisfactory slab deflection and bending stress predictions by the Pasternak solutions can be obtained by calculating subgrade shear modulus as the product of modulus of subgrade reaction and a coefficient θ. With reference to actual field measurements, the analysis in this study indicates that using a constant θ value of 0.35 m ² in the proposed Pasternak foundation model would achieve 1 to 25 improvements in the accuracy of pavement responses predictions as compared with the corresponding solutions given by models with Winkler foundation.