Modelling the behaviour of a disk of clay during pile driving using hypoplasticity

The bearing capacity of displacement piles in clay is usually seen to increase during the days following installation. This phenomenon is referred to as ‘set-up’ and occurs because during installation, the high strains imposed by the pile leave a mark on the state of the soil surrounding the pile (pore pressures, a.o.). Once installation has ended, the pore pressures generated during driving are free to dissipate, which allows the pile capacity to grow. This paper presents a numerical simulation of a plane strain soil disk adjacent to a pile which is being driven. Emphasis is placed on the simulation of the excess pore pressure during pile penetration and afterwards, during consolidation. The soil constitutive model used is hypoplasticity for clays coupled with intergranular strain, which allows capturing the soil small strain behaviour and dilatancy. The driving analysis is performed by using a dynamic integration scheme and the consolidation is coupled

Screw Piles - Installation and design in stiff clays

This volume provides a snapshot of the current thinking and development perspectives on the installation and design of screw piles within a framework of the Eurocode 7