Elliptical cylindrical equivalent model for consolidation of unsaturated soil improved by PVD

Abstract To consider the shape effect of prefabricated vertical drain (PVD), the elliptical cylindrical equivalent model (ECEM) is established for the consolidation of unsaturated soft foundations improved by PVD. Then, the associated analytical solutions of excess pore‐air and pore‐water pressures are derived under free strain and equal strain conditions, respectively. The rationality of proposed solutions is verified by comparing them with the existing solutions. Through conducting the parametric study, the effects of the permeability coefficients and the extent of influence zone on the dissipation of excess pore pressure and the consolidation settlement are investigated. Outcomes show that there is a plateau during the dissipation process of the excess pore‐water pressure. The consolidation behavior is dominated by the dissipation of the excess pore‐air pressure before the plateau, while it is governed only by the dissipation of the excess pore‐water pressure after the plateau.