Driven piles in clay - the effects of installation and subsequent consolidation

TLDR: In this article, the effects of installing a driven pile on the strength of the soil were investigated using a work-hardening elasto-plastic soil model, which has the unique feature of allowing the strength to change as the water content changes, thus it is possible to calculate the new intrinsic soil strength at any stage during consolidation.

Abstract: This paper describes the results of numerical analysis of the effects of installing a driven pile. The geometry of the problem has been simplified by the assumption of plane strain conditions in addition to axial symmetry. Pile installation has been modelled as the undrained expansion of a cylindrical cavity. The excess pore pressures generated in this process have subsequently been assumed to dissipate by means of outward radial flow of pore water. The consolidation of the soil has been studied using a work-hardening elasto–plastic soil model which has the unique feature of allowing the strength of the soil to change as the water content changes. Thus it is possible to calculate the new intrinsic soil strength at any stage during consolidation. In particular the long-term shaft capacity of a driven pile may be estimated from the final effective stress state and intrinsic strength of the soil adjacent to the pile. A parametric study has been made of the effect of the past consolidation history of the soil...