The document consists of lecture notes for a geotechnical engineering course, specifically addressing phase relationships and various soil property calculations. It includes multiple problems related to void ratio, porosity, water content, and specific gravity, providing detailed instructions for determining these parameters from given data. Additionally, references to textbooks on geotechnical engineering and soil mechanics are provided.

1. 1
Geotechnical Engineering–I [CE-221]
BSc Civil Engineering – 4th Semester
by
Dr. Muhammad Irfan
Assistant Professor
Civil Engg. Dept. – UET Lahore
Email: mirfan1@msn.com
Lecture Handouts: https://groups.google.com/forum/#!forum/geotech-i
Lecture # 5
7-Feb-2017

2. 2
REVIEW:
PHASE RELATIONSHIPS
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3. 3
PHASE RELATIONSHIPS
Problem #7
A cubic cm of soil in its natural moisture weighs 1.81g. After
being dried it weighs 1.54g. The specific gravity of the soil is
2.7. Determine the degree of saturation, void ratio, porosity,
and water content for the soil as it existed in its natural state.
Problem #8
A container of saturated soil weighed 113.27g before it was
placed in an oven and 100.06g after it remained in the oven
overnight. The container alone weighs 49.31g. Specific gravity
of the soil is 2.8.
Determine the void ratio, porosity, and water content of the
original soil sample.

4. 4
PHASE RELATIONSHIPS
Problem #9
A saturated soil has a unit weight of 1.92 g/cm3 and water
content of 32.5%. Determine the void ratio and the specific
gravity of soil.
Problem #10
A sample of dry sand having a unit weight of 1.68 g/cm3 and a
specific gravity of 2.7 is placed in the rain. During the rain the
volume of the sample remains constant but the degree of
saturation increase to 40%. Determine the unit weight and
water content of the soil after being in the rain.

5. 5
PHASE RELATIONSHIPS
Problem #11
A soil sample taken from a borrow pit has an in situ void
ratio of 1.15. The soil is to be used for a compaction project
where 100,000m3 is required in compacted state with the void
ratio predetermined to be 0.73. Determine how much is to be
excavated from the borrow pit.
Problem #12
Laboratory tests determined the water content in a certain soil
to be 14% at a degree of saturation of 62%. The density of soil
is 1.7 g/cm3. Determine.
a) The specific gravity
b) The porosity
c) The void ratio of the soil

6. 6
PHASE RELATIONSHIPS
Problem #13
A soil in its natural state was found to have a void ratio of
0.88 at a degree of saturation of 72 percent. If dry density of
the soil is 1.7g/cm3, determine
a) The specific gravity
b) The water content
c) The porosity of the soil mass

7. 7
PHASE RELATIONSHIPS
Problem #14
A moist soil sample weighs 346g. After drying at 1050C its
weight is 284g. The specific gravity of the mass and of the
solids is 1.86 and 2.7 respectively.
DETERMINE:
a) Water content
b) Void ratio
c) Degree of saturation
d) Porosity

8. 8
PHASE RELATIONSHIPS
Problem #15
A soil deposit is being considered as a fill for a building site.
In its original state in the borrow pit the void ratio is 0.95.
Based on a laboratory tests, the desired void ratio in its
compacted state at the building site should not be greater than
0.65.
FIND: The percentage decrease (or loss) of volume of the
deposit from its original state.

9. 9
PHASE RELATIONSHIPS
Problem #16
A Shelby-tube sampler is cut such that volume of the soil in
the cut piece is equal to 413cm3 (from the constant cross
sectional area and the average length of the specimen, one
can estimate the specimen’s volume expediently and
reasonably accurately). The weight of the mass was 727g.
After drying, the sample’s weight is 607g. Assume Gs = 2.65.
FIND:
a) Porosity
b) Void ratio
c) Porosity
d) Degree of saturation
e) Volumetric water content
f) Specific gravity of mass

10. 10
PHASE RELATIONSHIPS
Problem #17
A soil sample has a water content of 8% with a bulk density
of 1.9 g/cm3 and specific gravity Gs =2.66.
FIND:
a) Void ratio of sample
b) Degree of saturation
c) Porosity
d) How much water (in Kgs) should be added in 1m3 of this
soil in order to bring the water content to 13%, assuming
that the void ratio remains constant.

11. 11
PHASE RELATIONSHIPS
Problem #18
Why is the dry weight (weight of solids) rather than the total
weight used in defining the water content? Can the water
content exceed 100%?
Problem #19
A soil sample was determined to possess the following
characteristics: Gs =2.74, e = 0.69, w = 14 %
DETERMINE
a) Degree of saturation
b) Porosity
c) Unit dry weight of sample

12. 12
PHASE RELATIONSHIPS
Problem #20
A moist soil sample was found to have a volume of 22.3cm3
and weight of 29.7g. The dry weight of the sample was
determined to be 23g. Gs = 2.7
DETERMINE:
a) Void ratio
b) Water content
c) Porosity
d) Degree of saturation of sample

13. 13
PHASE RELATIONSHIPS
Problem #21
Laboratory tests on a soil sample yielded the following
information: Gs =2.7; w = 13%; γd=1.8g/cm3
CALCULATE
a) Void ratio
b) Degree of saturation
c) Volumetric water content
d) Porosity

14. 14
PHASE RELATIONSHIPS
Problem #22
A soil sample has a water content of 8% and a degree of
saturation 42% after adding some water, the degree of
saturation altered to 53%. Assuming no change in the volume
of the voids, Gs =2.7.
DETERMINE:
a) Void ratio
b) Water content
c) Specific gravity of the mass of the sample in the altered
state.

15. 15
CONCLUDED
REFERENCE MATERIAL
An Introduction to Geotechnical Engineering (2nd Edition)
By R. D. Holtz, W. D. Kovacs and T. C. Sheahan
Chapter #2
Geotechnical Engineering – Principles and Practices - (2nd Edition)
By Donald P. Coduto, M. R. Yeung and W. A. Kitch
Chapter #4
Fundamentals of Soil Mechanics
By M. S. Qureshi & Aziz Akbar
Chapter #3