Application of vacuum consolidation for sustainable transport infrastructure

Abstract

A system of vertical drains combined with vacuum preloading to accelerate soil consolidation by promoting radial flow is an effective method. In this paper, the analytical modelling of vertical drains incorporating vacuum preloading in an axisymmetric condition is proposed. The distribution of vacuum pressure along the drain and variations in volume compressibility, and permeability of soil based on large scale laboratory observations are included in the proposed solutions. These analytical predictions are compared with a case history taken from Thailand where the entire embankment was stabilised with vertical drains and subjected to vacuum preloading. This analysis employing the writer’s model indicates an improvement in the predictions in relation to the field observations. The data show that the efficiency of the prefabricated vertical drains depends on the magnitude and distribution of vacuum pressure, and the extent to which air is prevented from leaking.