Consolidation in detail

1. Submitted by:
Saurav Poudel (11)
Engineering Geology (2nd Semester)
Central Department of Geology,
Kritipur
Submitted to:
Dr. Ranjan Kumar Dahal
Associate Professor
Central Department of
Geology, Kritipur

2. OBJECTIVES
To find the answers of the questions, related to the paper
entitled, “Consolidation of Clay with Non-linear Viscosity” by
Barden, 1965.
The questions are as follows:
A. Why did Barden think that Terzaghi theory was oversimplified?
B. What Parameters described by Terzaghi are in discrepancies
with Barden’s major consideration?
C. What were the similarity between Terzaghi and Taylor’s
hypothesis? And what is the main difference?

3. Why did Barden think that Terzaghi’s theory
was oversimplified?
Barden thought that Terzaghi’s theory was oversimplified because of
the following reasons:
Terzaghi's idea was only accurate for consolidation in a single
dimension.
Terzaghi was unable to provide an explanation for the secondary
deformation brought on by the loss of pore water pressure.
Understanding a number of idealized "constants" that depend on the
stress route, like elastic moduli, is not necessary for understanding
Terzaghi's theory.
Terzaghi believed that soil behaved like a linearly elastic material, but
in reality, soil does not always behave elastically.

4. What Parameters described by Terzaghi are in
discrepancies with Barden’s major consideration?
When the value of c is derived from a compression-time plot, it is discovered that the rate
of mid-plane pore pressure dissipation is greater, especially in the early stages of the test,
which is not explained by Terzaghi's theory.
The settlement does not end when the pore pressure falls to zero; instead, it is typically
followed by secondary or creep deformation under constant effective stress, which has
likely been happening from the test's inception.
According to Terzaghi's theory, the soil's presumed rheological behavior is the only major
source of error. However, the solution shows that the thickness of the sample and the
pressure increment ratio both have an impact on inaccuracies.
According to Taylor's theory, the Terzaghi film bond is replaced by a "plastic structural
resistance to compression" denoted by and which depends on the rate of shear strain that
Barden mentions.

5. CONTINUED
Secondary compressions of the type examined (one-dimensional) will
be insignificant at the field size, with the exception of soils exhibiting
extraordinary creep properties, such as peat.
Terzaghi’s theory indicates three assumptions which could possibly be
responsible for the important discrepancies which are mentioned below.
The validity of Darcy’s law.
Constant permeability and compressibility over a given pressure
increment.
A void ratio-effective stress relationship independent of time (no creep).

6. What were the similarities between Terzaghi and
Taylor’s hypothesis? And what is the main
differences?
The majority of calculations for
settlement and stability evaluations, as
well as in unique cases where the stress
route is taken into account, are primarily
based on Terzaghi's theory.
Consolidation on the primary and
secondary levels is carried out
continuously.
The progressive realignment of the
skeleton following the disruption or
remoulding induced by primary
compressions is the source of secondary or
creep effects.
Differences
While Taylor believed that soil was viscoelastic,
Terzaghi thought it was linearly elastic.
While Taylor primarily addresses primary
consolidation in his theory, Terzaghi
qualitatively analyzes the entire continuous
process of primary and secondary consolidation.
Similarities

7. THANK YOU!