Environmental Engineering Reference
In-Depth Information
60
H = 100 mm
H = 300 mm
H = 600 mm
H = 800 mm
50
40
30
20
10
0
10 6
1.5 × 10 6
2 × 10 6
2.5 × 10 6
0
500,000
Time, t (s)
Figure 7.48 Measured matric suction profiles during capillary rise for ML soil (after Li et al.,
2009).
value of 1.2 kPa, which was close to the steady-state value
of 1.0 kPa at that section.
values are inserted directly into Eq. 7.80, the permeability
functions can be calculated. Figures 7.49 to 7.51 show
the calculated permeability functions for the CL, ML, and
SC soils (i.e., using open symbols). Soil suctions larger
than 80 kPa could not be monitored due to the limited
range of tensiometers. Therefore, the directly calculated
permeability function values are limited to a narrow
suction range.
7.6.4.3 Calculation of Unsaturated Soil Permeability
Functions
The water contents and soil suctions during the infiltration
versus capillary rise process can be used to calculate the
permeability function using Eq. 7.80. If measured suction
10 5
10 8 - 3
10 7
k s = 3
×
×
10 6
10 7
10 8
10 9
10 10
λ
=
2.18
Gardner (1958a) fit
Monitored suction, H = 100 mm
Monitored suction, H = 300 mm
Inferred suction, H = 100 mm
Inferred suction, H = 300 mm
Inferred suction, H = 600 mm
10 11
10 12
10 13
0.01
0.1
1
10
100
1000
10,000
100,000
Soil suction, ψ (kPa)
Figure 7.49 Calculated unsaturated permeability functions for CL soil (after Li et al., 2009).
 
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