Negative Skin Friction on Piles Based on Finite Strain Consolidation Theory and the Nonlinear Load Transfer Method

The development of dragload and downdrag on single piles in consolidating ground is investigated in this study with a simplified one-dimensional soil-pile model that combines the nonlinear load transfer method and finite strain consolidation theory to analyze soil-pile interaction under the effects of negative skin friction. In order to directly relate the soil settlements and effective stresses through the strain as a function of time and depth during the consolidation process, the prediction of the soil settlements imposing downdrag are based on Mikasa's generalized one-dimensional consolidation theory that are formulated in terms of finite strain. An illustrative example and a case study of test pile were analyzed and predicted results of dragload and pile shortening by the presented model were shown to be in fair agreement with measured reference data. The model presented in this study offers a simple and flexible method for the analysis of a variety of soil-pile interaction problems under negative skin-friction that can account for nonlinearity of the soil and pile, a rigid and deformable bearing stratum, and can be applicable for the analysis of floating and end-bearing piles as well as for shafts socketed in rocks.