UNIVERSITY OF SOUTH AFRICA
College of Science, Engineering and Technology
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GEE2601: Geotechnical Engineering II
Assignment 1 | Year Module
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GEE2601
Module Code:
Geotechnical Engineering II
Module Name:
Soil Properties, Permeability and Flow Nets
Essay Topic:
Assignment 1
Assignment Number:
Submitted in partial fulfilment of the requirements for Geotechnical Engineering II, UNISA
, UNISA | GEE2601 Geotechnical Engineering II
Question 2.4.1
A sample of soil is compacted into a 1.235 × 10−3 m3 laboratory mold. The mass of the com-
pacted soil is 2.32 kg and its moisture content is 12.5%. Using a specific gravity of solids of
2.71, compute the:
• Degree of saturation
• Density (kg/m3 )
• Unit weight (kN/m3 )
Given
Volume, V = 1.235 × 10−3 m3
Mass of wet soil, M = 2.32 kg
Moisture content, w = 12.5% = 0.125
Specific gravity, Gs = 2.71
Unit weight of water, γw = 9.81 kN/m3
Density of water, ρw = 1000 kg/m3
Step 1: Calculate dry mass
M
Md =
1+w
2.32
Md =
1.125
Md = 2.0622 kg
Step 2: Calculate density
M
ρ=
V
2.32
ρ=
1.235 × 10−3
ρ = 1878.54 kg/m3
Page 2 of 4
College of Science, Engineering and Technology
⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄⋄
GEE2601: Geotechnical Engineering II
Assignment 1 | Year Module
⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄ ⋄⋄
GEE2601
Module Code:
Geotechnical Engineering II
Module Name:
Soil Properties, Permeability and Flow Nets
Essay Topic:
Assignment 1
Assignment Number:
Submitted in partial fulfilment of the requirements for Geotechnical Engineering II, UNISA
, UNISA | GEE2601 Geotechnical Engineering II
Question 2.4.1
A sample of soil is compacted into a 1.235 × 10−3 m3 laboratory mold. The mass of the com-
pacted soil is 2.32 kg and its moisture content is 12.5%. Using a specific gravity of solids of
2.71, compute the:
• Degree of saturation
• Density (kg/m3 )
• Unit weight (kN/m3 )
Given
Volume, V = 1.235 × 10−3 m3
Mass of wet soil, M = 2.32 kg
Moisture content, w = 12.5% = 0.125
Specific gravity, Gs = 2.71
Unit weight of water, γw = 9.81 kN/m3
Density of water, ρw = 1000 kg/m3
Step 1: Calculate dry mass
M
Md =
1+w
2.32
Md =
1.125
Md = 2.0622 kg
Step 2: Calculate density
M
ρ=
V
2.32
ρ=
1.235 × 10−3
ρ = 1878.54 kg/m3
Page 2 of 4
