Construction materials and testing
1
Properties of Soil
Situation 1.
The sample of soil weighing 30.6 kg had a volume of
0.0183m
3
. The sample is allowed to dry in an oven and the
weight was reduced to 27.2 kg. The specific gravity of the
solids was found to be 2.65. Determine the following:
1.
Moist unit weight of soil in kN/m
3
2.
Dry unit weight of soil in kN/m
3
3.
Moisture content
4.
Void ratio
5.
Porosity
6.
Degree of saturation
Situation 2.
The soil sample in natural state having a volume of 0.0012 m3
weighs 1.73 kg. The degree of saturation being 61.6%. After
drying in an oven the final weight of sample was 1.44 kg.
Determine the follo wing:
7.
Specific gravity of solid
8.
Void ratio
9.
Critical hydraulic gradient
Situation 3.
The moist soil having a volume of 0.0154 m3 has a unit weight
of 16.5 kN/m3 and a moisture content of 15%. If the specific
gravity of solid is 2.7. Determine the following:
10.
Degree of Saturation
11.
Volume of air in the original sample
12.
Weight of water to be added to reach full saturation
Compaction
Situation 4.
The moist unit weight of sample of soil is 17.43 kN/m3. It has
a specific gravity of solid of 2 .65 and water content of 16%.
The sample has a void ratio of 0 .88 in the loosest condition
and 0.36 in the densest condition.
13.
Compute the density index
14.
If the dry unit weight at optimum water content was
19.12 kN/m
3
, what is the minimum dry unit
Situation 5.
A proposed embankment fill requires 5000 m3 of compaction
soil. The void ratio of the compacted fill is specified as 0.70.
Three borrow pits are available as described in the following
table.
Borrow Pit
Void Ratio
Cost/m
3
A
0.85
P830
B
0.95
P760
C
1.10
P720
What is the total cost for acquiring soil from:
15.
Borrow Pit A?
16.
Borrow Pit B?
17.
Borrow Pit C?
Situation 6.
A sand cone test has been performed in a compacted fill of
soil. The test results were as follows:
Initial mass of sand cone apparatus w/ sand = 5.912 kg
Final mass of sand cone apparatus w/ sand = 2.378 kg
Mass of soil recovered from hole = 2.833 kg
Moisture content of soil from hole = 7%
Density of sand =1300 kg/m3
Volume of cone below valve =1.114 x 103 m3
Max. dry unit weight =19 kN/m3
Determine the following:
18.
Moist unit weight
19.
Dry Unit Weight
20.
Relative compaction
Situation 7.
A sample of dry coarse-grained material was taken through
a layer of sieves and the following results were obtained:
Sieve no.
Openings
(mm)
Mass of soil retained
(grams)
4
4.76
46.0
10
2.0
165.6
20
0.84
92.0
40
0.42
55.2
60
0.25
23.0
100
0.149
36.8
200
0.074
23.0
Pan
18.4
Determine the following:
21.
Effective particle size
22.
Uniformity coefficient
23.
Coefficient of curvature
Problems for Practice
Situation 8.
A saturated soil has a unit weight of 18.85 kN/m
3
and water
content of 32%. Determine the following:
1.
Specific gravity of solid (2.725)
2.
Porosity (0.466)
3.
Submerged unit weight
(9.04)
Situation 9.
The relative compaction of sand in the field is 94%. The
maximum and minimum dry unit weights of the sand are
16.2 kN/m
3
and 14.9 kN/m
3
respectively. For the field
condition determine the following :
4.
Dry unit weight (15.23)
5.
Relative density of compaction (27%)
6.
Moist unit weight at moisture content of 8% (16.45)
Situation 10.
A proposed earth fill needs 30,000 m3 of soil and be compacted
to 95% of Standard Proctor dry density. Tests indicate that the
max dry density is 19.4 kN/m3 at an optimum water content of
16%. The borrow material in its natural condition has a unit
weight of 17.6 kN/m3 and water content of 12%. Determine the
following:
7.
Total volume of borrow required (35,194)
8.
Volume of void of borrow material if Gs = 2.671 (14,077)
9.
Quantity of water to be added to bring the soil to the
optimum moisture content. (2254)
