Civil Engineering Reference
In-Depth Information
Example 1.5:
Soil classification (ii)
A set of particle size distribution analyses on three soils, A, B and C, gave the following
results:
Percentage passing
Sieve size (mm)
Soil A
Soil B
Soil C
20
90
-
-
10
56
-
-
6.3
47
-
-
2
44
-
-
0.6
40
95
-
0.425
-
80
-
0.300
29
10
-
0.212
-
3
-
0.150
-
-
100
0.063
5
1
91
Soil C
: Since more than 10% passed the 63
μ
m sieve, a pipette analysis (described in
BS 1377: Part 2 and by Head (
1992)
) was performed. The results were:
Percentage passing
Particle sizes (mm)
Soil C
0.04
78
0.02
61
0.006
47
0.002
40
Soil C was found to have a liquid limit of 48% and a plastic limit of 21%.
Plot the particle size distribution curves and classify each soil.
Solution:
The particle size distribution curves for the three soils are shown in Fig.
1.9.
The curves
can be used to obtain the following particle sizes for soils A and B.
Soil
D
10
(mm)
D
30
(mm)
D
60
(mm)
A
0.1
0.31
11.0
B
0.3
0.42
0.44
