Numerical analysis of the deep soil failure mechanism for perimeter pile groups

In this paper, the lateral limiting pressure offered by deep ‘flow-around’ soil failure mechanism for perimeter (ring) pile groups in undrained is explored using two-dimensional finite-element (FE) modelling. A parametric study investigates role of group configuration, pile–soil adhesion, size, spacing and load direction on capacity corresponding mechanisms. The FE output shows that plan configuration (square or circular) has a negligible influence closely spaced groups. When compared to ‘full’ square with same number piles, present results suggest practical (≳ two diameters), do not necessarily increase efficiency, particularly if piles are smooth. Nevertheless, shown be characterised both invariance their loading highly uniform load-sharing between which beneficial features optimise design.