SOIL COMPOSITION

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SOIL COMPOSITION
-Ms Ikmalzatul
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Soil A 3-Phase Material
Air
Water
Solid
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The Mineral Skeleton
Solid Particles
Volume
Voids (air or water)
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Three Phase Diagram
Idealization Three Phase Diagram
Mineral Skeleton
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Fully Saturated Soils
Mineral Skeleton
Fully Saturated
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Dry Soils
Air
Solid
Dry Soil
Mineral Skeleton
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Partly Saturated Soils
Mineral Skeleton
Partly Saturated Soils
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Three Phase System
Va
Wa0
Vv
Vw
Ww
WT
VT
Ws
Vs
Volume
Weight
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Weight Relationships

• Weight Components
• Weight of Solids Ws
• Weight of Water Ww
• Weight of Air 0

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Volumetric Relationships

• Volume Components
• Volume of Solids Vs
• Volume of Water Vw
• Volume of Air Va
• Volume of Voids Va Vw Vv

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Volumetric Relationships

• Volume Components
• Volume of Solids Vs
• Volume of Water Vw
• Volume of Air Va
• Volume of Voids Va Vw Vv

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Specific Gravity

• Unit weight of Water, ?w
• ?w 1.0 g/cm3 (strictly accurate at 4 C)
• ?w 62.4 pcf
• ?w 9.81 kN/m3

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Specific Gravity

• Iron 7.86
• Aluminum 2.55-2.80
• Lead 11.34
• Mercury 13.55
• Granite 2.69
• Marble 2.69
• Quartz 2.60
• Feldspar 2.54-2.62

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Specific Gravity, Gs
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Example Volumetric Ratios

• Determine void ratio, porosity and degree of
  saturation of a soil core sample
• Data
• Weight of soil sample 1013g
• Vol. of soil sample 585.0cm3
• Specific Gravity, Gs 2.65
• Dry weight of soil 904.0g

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Example
Air
Wa0
Water
?W 1.00
109.0g
Solid
?s 2.65
Volumes
Weights
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Example
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Soil Unit weight (kN/m3)

• Bulk (or Total) Unit weight
• ? WT / VT
• Dry unit weight
• ?d Ws / VT
• Buoyant (submerged) unit weight
• ?b ?- ?w

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Typical Unit weights
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THE END