The Coefficient of Subgrade Reaction and Its Accuracy on Design of Foundations

In this paper different methods proposed for determination of ks are discussed, compared and evaluated for their suitability and accuracy. The geotechnical parameters of a site on Tabriz Marl were selected as the base data and settlement analysis results with different methods were compared with that of obtained from analyses with advanced soil models using Safe and Plaxis soft wares. It was disclosed that for Tabriz Marl, soft soil model is the best governing model and Vesic relation among the methods of determination of ks leads to a negligible error in comparison to the soft soil model. Also, in order to achieve more accurate results from these methods, it is proposed to use mean elasticity modulus which takes into account the effect of geometric and mechanical properties of sub-layers