Development of a calibrated Pasternak foundation model for practical use

Abstract

A calibrated continuum foundation model of the order same as those of Pasternak, Filonenko-Borodich, and Vlasov is developed. This is achieved by seeking equality of the surface deformation of a Pasternak-type model with that of a calibrated Kerr-type model presented recently without neglecting any stress, strain, or deformation component in the continuum. In order to alleviate the sensitiveness of the model parameters to the layer thickness, this is eliminated from the corresponding expressions through the introduction of a dimensionless calibration parameter. The superiority of the new model over existing models of similar order has been demonstrated. Closed-form calibrated relationships for the two parameters of the new model are provided together with values of the calibration factor. The use of the model is illustrated on a basic problem of a beam on an elastic foundation. As a Pasternak-type model is more familiar to engineers and much easier to handle in applications than a Kerr-type model, its use in practice is recommended. The new model completes a series of calibrated models at three different levels: Winkler, Pasternak, and Kerr as proposed recently by the author.

Settlements and Subgrade Reactions of Surface Raft Foundations Subjected to Vertically Uniform Load

“…As the resulting coefficient of subgrade reaction (i.e., the soil spring constant, k s ) plays a key role in the structural design of foundations, numerous soil spring models have been developed since 1950. Besides the beam on elastic foundation model (Winkler's model), the so called two-parameter soil spring model proposed by Pasternak [14], which can account for the elastic shear influence on the surrounding soil, has been adopted and modified by numerous researchers [15][16][17][18]. Such models have disadvantages in modeling layered soil profiles.…”