Civil Engineering Reference
In-Depth Information
Fig. 12.4
Theoretical consolidation curves.
Permeable
Permeable
2H
2H
Permeable
Impermeable
(a) Two-way drainage
(b) One-way drainage
Fig. 12.5
Drainage path length.
12.6 Determination of the coeficient of consolidation, c
v
, from the
consolidation test
If, for a particular pressure increment applied during a consolidation test, the compression of the test
sample is plotted against the square root of time, the result shown in Fig.
12.6
will be obtained.
The curve is seen to consist of three distinct parts: AB, BC and CD.
●
AB (initial compression or frictional lag)
A small but rapid compression sometimes occurs at the commencement of the increment and is prob-
ably due to the compression of any air present or to the reorientation of some of the larger particles
