Modelling load-displacement response of driven piles in cohesionless soils under tensile loading

A new methodology for deriving the uplift load-displacement response of long driven piles in cohesionless soils is proposed. This method accounts for the effects of the friction fatigue processes during pile driving and the existence of locked-in residual stresses at the end of pile driving before commencing the pile load test. A hyperbolic formulation is utilized to simulate the nonlinear load transfer curves (the so-called t-z curves). The utility of this technique is demonstrated for a field pullout load test on a driven pile in sand. Predicted and measured load-displacement curves showed good agreement, indicating that this approach yields reasonable results as long as representative input parameters are employed.