Lesson 1/Practice Exercise
Use the Grain Size Distribution Graph (next page) to answer the following questions:
8.
What are the percentages of distribution?
a.
Gravel
= ___________________
b.
Sand
= ___________________
c.
Fines
= ___________________
9.
What is the predominant material?
10.
Which set of data is correct?
a.
D60 = 1.5
b.
D60 = 1.1
c.
D60 =2.7
D30 = 1.3
D30 = 2.7
D30 = 1.1
D10 =.24
D10 = 2.0
D10 = .2
11.
What is the Coefficient of Uniformity?
Cu
= _____________ .
12.
What is the Coefficient of Curvature?
Cc
= _____________ .
13.
What is the gradation?
a.
poorly-graded; gap-graded
b.
poorly-graded; uniformly graded
c.
well-graded
14.
If the soil contains so much moisture that it is at the liquid state, the material
a.
crumbles under pressure.
b.
may be rolled into a 1/8-inch thread before crumbling.
c.
deforms under pressure and remains in that form.
d.
flows under its own weight.
15.
Using the Atterberg limits to determine moisture content if you take a sample and roll it into a
1/8-inch diameter thread one time before it breaks, that soil sample is said to be
a.
highly compressible
b.
fat
c.
at the plastic limit
d.
at the liquid limit
16.
When a soil plots in the box at the base of the A-line on the Casagrande Plasticity Chart, the soil
is
a.
high compressible clay
b.
either clay or silt
c.
primarily silt
d.
impossible to determine
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