Hh. Vaziri et Ha. Christian, APPLICATION OF TERZAGHIS CONSOLIDATION THEORY TO NEARLY SATURATED SOILS, Canadian geotechnical journal, 31(2), 1994, pp. 311-317
Terzaghi's one-dimensional consolidation theory is modified to account
for the compressibility of fluid and solid phases. The proposed modif
ied equations can be used to analyze the consolidation response of uns
aturated soils over the saturation range where the gases remain in an
occluded form (generally within a range between 80 and 100% saturation
); however, such applications are subject to the same limitations and
idealizations implicit in Terzaghi's classical consolidation theory. T
he purpose of this note, therefore, is to offer a simple solution and
not to unravel the complexities involved in general analysis of flow a
nd deformation response of unsaturated soils. The proposed approach in
volves defining the consolidation coefficient, and hence the time fact
or, in terms of an equivalent fluid compressibility. This equivalent f
luid is assumed to represent the compressibility characteristics of al
l the compressible phases that constitute the soil skeleton. The propo
sed generalized form of Terzaghi's consolidation equations is shown to
qualitatively capture the consolidation behaviour of unsaturated soil
s. To test the validity of the formulations presented, one-dimensional
oedometer tests were performed on specimens of Lantz clay that had be
en prepared at different saturation levels; satisfactory agreement was
achieved between the theoretical and measured data at two states of s
aturation.