Development of semi empirical method for predicting axial pile capacity

Abstract

This study aims to estimate the axial pile capacity through the use of semi empirical analysis based on limit equilibrium theory and SPT data. An interesting alternative for improving the quality of bearing capacity prediction from the rational methods of plasticity is the definition of the required mechanical parameters, by correlation with those obtained from in-situ tests. In this context, Aback-calculation of mechanical parameters required by the numerical method has been carried out for calibrating the calculated limit vertical load to the interpreted load tests. It is established through the incorporation of approximately 60 data sets of pile loading tests on driven piles in sandy soils obtained from data published in the literature. Consequently, base and shaft resistances factors are estimated. The assessment of the predictive performance of the new method against a number of traditional SPT-based approaches indicates that the developed method can be used as an alternative for determining the bearing capacity of piles in geotechnical practice. For practical purposes, the end and shaft bearing resistances factors were proposed in relation with the N-SPT value.