Behaviour of expanded piles under upward loading due to radial preloading in soft clay

Abstract

A two-dimensional numerical analysis was employed to evaluate the radial preloading effects on the bored piles bearing capacity under upward loading. Verification of the numerical model was conducted by comparing the calculated allowable load capacity based on a series of physical models in the small scale. Interpretations of the finite elements models were focused on the load-displacement behaviour, the effect of the increase in the pile diameter on the pile load capacity, deformation of the surrounding soil due to radial preloading and comparison of different constitutive models. The results revealed that the bearing capacity is increased due to impose of radial preloading for bored piles, meaningfully. In addition, the effect of the radial preloading is increased on the bearing capacity with increase in the pile diameter. In another aspect, the simulation of the pile behaviours based on the different constitutive models demonstrated that soft soil model can properly simulate pile behaviour due to radial preloading in comparison with Mohr-Coulomb model.