Consolidation behavior of soils subjected to asymmetric initial excess pore pressure distributions with one-way drainage

Abstract

A consolidating clay layer can be singly or doubly drained. The degree of consolidation is a function of the initial excess pore pressure distribution and the drainage conditions. Traditional geotechnical engineering practice assumes a uniform initial excess pore pressure distribution, for which the singly drained and doubly drained solutions to Terzaghi's one-dimensional consolidation theory are available in most textbooks. In this paper, several symmetric and asymmetric initial excess pore pressure distributions are studied using a series solution method. Excess pore pressure isochrones and average degree of consolidation plots are generated for all cases, assuming an impervious boundary at the base of the clay stratum. These plots enable users to determine the average degree of consolidation and pore pressure at a specific depth for a variety of loading scenarios. Pore pressure redistribution is also clearly more prevalent in singly drained clays, where pore-water pressures at certain depths increase at certain times, a phenomenon not generally expected during consolidation.