Importance of soil

1. SOILSOIL
EsraaEsraa HusseinHussein
MohamedMohamed
1410462214104622
Dr. MohamedDr. Mohamed
HamadaHamada

2. Outline:
• Definition
• The Importance of Soil
• Soil Composition
• Soil forming factors
• Weathering
• Geotechnical engineering
• Why we study the soil before building on
them?
• Characteristics of different types of soils

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WHAT IS SOIL ?
• Soil is the mixture of
minerals, organic
matter, gases, liquids,
and the countless
organisms that
together support life
on Earth.
• Soil is a natural body
known as the
pedosphere.

4. The Importance of Soil
• Sustain plant and
animal life both
above and below
the surface
• Regulate water and
solute flow.
• Store and cycle
nutrients.
• Provide support for
buildings and
structures

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1.Parental Material: The primary material from
which the soil is formed.
2.Climate: weathering forces break down
parent material.
3.Organisms: All plants and animals living in
or on the soil.
4.Topography: The location of a soil on a
landscape can affect how the climatic processes
impact it.
5.Time: All of the above factors assert
themselves over time

6. Weathering
• Weathering is the physical
breaking-down and
chemical alteration of the
soil.
• Physical weathering is the
disintegration of rock
without changing its
chemical composition.
• Chemical weathering is
the decomposition of soil
particles by chemical
alteration.

7. Soil Composition
• Soil generally consists of
organic and inorganic
materials, water and air.
• The inorganic materials are
the rocks that have been
broken down into smaller
pieces.
• The organic material is
decaying living matter (plants
or animals).
• The amount of water and air
in the soil is closely linked
with the climate and other

8. Geotechnical engineering
Geotechnical engineering is a branch of civil
engineering concerned with the engineering
behavior of earth materials.

9. Why we study the soil before
building on them?
• To achieve the security system of the building
• To choose the design of the structural system
depends on soil foundation and earthquake
behavior.
• To avoid defects of futuristic building

10. Engineering properties of soil
• Cohesion
• Angle of internal
friction
• Capillarity
• Permeability
• Elasticity
• Compressibility

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Soil problems
• Landslides in the surface soil layer.
• The gaps on the surface of the earth sign of the
presence of other gaps under the earth’s surface.

12. Soil Erosion
• Erosion is the displacement of soil
and rock by ocean currents, wind,
water, or ice.
• A certain amount of erosion is
natural and, in fact, healthy for the
ecosystem.
• Erosion Factors
› Precipitation
› Soil composition
› Slope Gradient
› Vegetation
› Land use

13. • Laguna Beach Landslide, June 2005. Extremely heavy winter
rainfall had soaked the soil and raised groundwater,
destabilizing the slopes of Bluebird Canyon. This home was
undermined and eleven homes were destroyed

14. Black Soil
Characteristics
of Different
types of soils

15. BLACK SOIL Also known as Regur or Black Cotton
soil. Dark grey to Black in color. High clay content.
Highly moist retentive. Develops cracks in summer..
Highly suitable for cotton. Rich in iron, lime,
calcium,Magnesium,carbonates, and alumina.

16. DESERT SOIL Contains soluble salts. Originated by
Mechanical disintegration & wind deposit. Porous and
coarse. 90% sand & 5% clay. Rich in Nitrates &
Phosphates. Poor in Nitrogen & Humus. Friable, sandy
& low moist content.
Desert soil

17. Red soil

18. RED SOIL Formed due to weathering of old
crystalline rocks. More sandy and less clayey.
Rich in iron, small amount of Humus. Poor in
phosphorus, nitrogen and lime. Slightly acidic
and do not retain moisture. 3.5 lakhs sq.km area.
Porous and Friable.

19. Clay

20. Clay is a naturally
occurring aluminium silicate
composed primarily of fine-
grained minerals.
Clay deposits are mostly
composed of clay minerals, a
subtype of phyllosilicate
minerals, which
impart plasticity and
harden when fired or dried; they also may contain variable
amounts of water trapped in the mineral structure by polar
attraction. Organic materials which do not impart plasticity
may also be a part of clay deposits.

21. Laterite soil• LATERITE SOIL Latin
word meaning brick.
Formed under high
temperature and rainfall
with wet and dry spell.
Silica is leached due to high
rainfall.
Remnants of iron and aluminum oxides left behind is
know as Laterite. Brown to Yellowish color. Becomes
hard when exposed to atmosphere. Used as building
material