Iraqi Journal of Civil Engineering

In this paper, a practical method of analysis of pile displacements is proposed based on the theory of load-transfer curves widely used in pile design and analysis. The parameters of the load-transfer curves for piles under axial load (called t-z, q-z curves) and lateral load (called P-Y curves) were correlated with the number of blows Nspt measured during the standard penetration test (SPT). Well-documented case histories of fullscale axial or lateral loading tests on single piles in sand were collected, and the analysis of the experimental results led to define the parameters of the load-transfer curves. Two practical computation methods of a single pile under an axial or a lateral load were roposed to be used within the scope of a pile foundation project. Finally, a validation process of the loadtransfer curves was undertaken by directly comparing the predicted pile displacements to those measured during other pile loading tests, showing good predictive capability for the two proposed methods.