Behaviour of single pile in consolidating soil

Abstract

Piles located in consolidating soil are subjected to indirect loading resulted from the settlement of adjacent soil. Both pile and soil undergo downward movements caused by the axial pile load and surcharge loading on surrounding area. Both dragload and downdrag imposed on the pile are time dependent. The purpose of this research was to analyse and quantify the dragload and down drag imposed on single pile. Effect of pile head load was considered. Shielded and unshielded piles are analysed. Three dimensional nonlinear analyses using ABAQUS 6.12 have been utilised. The research investigates the size of the surcharge loaded area, location of the pile tip and pile head load on the dragload and down drag imposed on the pile. Based on numerical results the study revealed that sacrificing piles, which are unloaded piles, “hang up” the soil between the piles in the group and, thus, the vertical effective stress around the shielded pile is reduced. Numerical results proved that an average value of the shear stress mobilisation factor β mobilised along unloaded shielded central pile varies between zero at neutral plane (NP) and 0.27. The long term dragload of the shielded floating pile is about 67% of the long term dragload of unshielded floating single pile.