Environmental Engineering Reference
In-Depth Information
FIGURE 3.4
The moisture-density relationship. The soil does not become
fully saturated during the compaction test.
Water content (
w
%)
FIGURE 3.5
Typical compaction curve for cohesionless sands
and sandy gravels. (From Foster, C. R.,
Foundation
Engineering
, G. A. Leonards, Ed., McGraw-Hill
Book Co., New York, 1962, pp. 1000-1024. With
permission. Reprinted with permission of the
McGraw-Hill Companies
.
)
Dry
Water content (
w
%)
S
= 100%
Silty
sand
(SM)
131
120
Sandy
clay
(SC)
114
Low plasticity
clay(CL)
FIGURE 3.6
Typical standard Proctor curves for various
materials.
8
Water content (
w
%)
12
15
Gradation (Grain Size Distribution)
Gradation refers to the distribution of the various grain sizes in a soil specimen plotted as
a function of the percent by weight passing a given sieve size
(Figure 3.9):
Well-graded
— a specimen with a wide range of grain sizes.
●
Poorly graded
— a specimen with a narrow range of grain sizes.
●
Skip-graded
— a specimen lacking a middle range of grain sizes.
●
