Analytical solution and numerical simulation of vacuum consolidation by vertical drains beneath circular embankments

This paper presents an analytical solution and numerical simulation of vacuum consolidation beneath a circular loading area (e.g. circular oil tanks or silos). The discrete system of vertical drains is substituted by continuous concentric rings of equivalent drain walls. The effectiveness of the vacuum as distributed along the drain length and the well resistance of the drains are considered. A rigorous solution of radial drainage towards cylindrical drain walls is presented and compared to numerical FEM predictions. The model is then successfully adopted to analyse the vacuum consolidation of a circular embankment in the Ballina field testing facility in Australia.