Geoscience Reference
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H
w
(a)
H
w
(b)
H
2
H
d
H
d
H
1
H
1
(c)
H
w
(d)
H
w
H
2
H
4
H
d
H
d
H
1
H
3
H
1
Fig. 8.17 Example sequence showing how an initially saturated material is drained to a suction
H
1
, after
which it is refilled to
H
2
and subsequently drained again to
H
3
and rewetted to
H
4
. The area to
the left of the line dividing the inside of the triangle represents empty pore space and the area to
the right is pore space filled with water.
characteristic as
0
∂θ
∂
H
d
=
F
(
H
d
,
x
)
dx
(8.9)
x
=
H
d
Hence one has finally
2
∂
θ
F
=
(8.10)
∂
H
d
∂
H
w
This can be integrated to yield different primary and secondary scanning curves during
wetting and drying.
Example 8.2. Sequence of alternate wetting and drying
To illustrate the procedure, assume as shown in Figure 8.17, that an initially satiated material
is drained to a suction
H
1
, after which it is refilled to
H
2
and subsequently drained again to
H
3
and rewetted to
H
4
. The successive integrations can be performed as follows to obtain
