Abstract: Installation of a preformed pile gives rise to residual stress locked in the pile. Such stress is difficult to be measured in-situ, hence little focus has been paid on its significant effect. Alternatively, a simulation approach is put forward in this study by incorporating the principle of energy conservation. The proposed model adopts assumptions that the load transfer behavior along the pile-soil interface is ideally elastoplastic and the distribution of residual friction resembles a folded line. By looking through the physical process of pile penetration and rebound, the energy equilibrium equation during pile installation is established on a primary consideration of the elastic deformation energy of pile. Parametric studies show that the ratio of pile length to pile diameter and the interface shear friction are two key issues affecting pile residual stress. The rationality of this model is assessed against the measured post-installation residual stress of a full-scale pile.

Key words: preformed pile, residual stress, energy conservation, simulation