ADHESION FACTORSFOR PILE FOUNDATIONS IN RESIDUAL SOILS OF SOUTHERN AFRICA

Abstract

Currently in Southern Africa the selection of adhesion factors (α-values) for computation of pile shaft capacity is based on published empirical correlations. Such correlations were developed on the basis of databases specific to certain geological setups and extrapolation of such empirical correlations to the Southern African distinct geologic environment may not give satisfactory results. Accordingly, this paper develops empirical correlations more suited for Southern African conditions. Regression analysis was used to establish the appropriate correlation schemes between back calculated α-values generated from local pile load test databases and the associated undrained shear strengths.  The results in the form of the regression trend lines exhibit similar characteristics with those reported in the literature.