Consolidation Analysis for Unsaturated Soils

This paper deals with the multidimensional consolidation of unsaturated soils when both the air phase andwater phase are continuous. Following the approach proposed by D.G. Fredlund and his coworkers, the differentialequations governing the coupled and uncoupled consolidation are first derived and then solved numerically. The solutionis achieved using a procedure that depends on the transformation of the field equations by using the Fourier transform.This transformation has the effect of reducing a two- or three-dimensional problem to a problem involving only asingle spatial dimension. The transformed equations are solved using a finite element approximation that makes use ofsimple one-dimensional elements. Once the solution in the transformed domain is obtained, the actual solution isachieved by inversion of the Fourier transform. The time integration process is formulated in a stepwise form. Resultsare presented to point out some aspects of the consolidation in unsaturated soils. Moreover, it is shown that the resultsobtained using the simple uncoupled theory are of sufficient accuracy for practical purposes.