A load-transfer curve formulation to predict the drained response of offshore piles to pull-out

The study introduces a formulation for load-transfer curves t-z to predict the load-displacement behaviour of offshore steel piles subjected to axial tensile loading. This condition is particularly relevant to foundations for wind turbines in intermediate to deep water, supporting jackets or anchoring floating structures. The problem is first addressed using a continuum approach implemented with the finite element method. Interface behaviour is modelled using the results of interface tests. Available data from pile tests, featuring different geometries, are used to assess the model ability to reproduce the experimentally observed response. The results of the finite element analyses are then used to develop and calibrate the t-z curves, which are implemented in a simpler one-dimensional finite element model. The comparison of the results of the two-dimensional and one-dimensional approaches shows good agreement. It is also shown that the one-dimensional approach can be successfully implemented using the equations of the recently developed unified CPT method.