Geotechnical engineering is a branch of civil engineering focused on the behavior of earth materials, involving the investigation of subsurface conditions and the design of foundations, earthworks, and retaining structures. It has historical roots dating back to prehistoric times and is crucial for applications such as foundation design, pavement design, and the construction of underground structures. A thorough understanding of geotechnical principles is essential for addressing risks related to natural hazards and ensuring the stability and durability of construction projects.

1. GEO-TECHNICAL ENGINEERING &
IT’S REAL TIME APPLICATIONS

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 Geotechnical engineering can be defined as a branch
of civil engineering concerned with the engineering
behavior of the earth's materials.
 The knowledge of theoretical geotechnical
engineering, assuming the soil to be an ideal elastic
isotropic and homogeneous material, helps in
predicting the behaviour of the soil in the field.

3. WHAT IT IS INCLUDES ?
It includes investigating existing subsurface conditions
and materials.
determining their physical/mechanical and chemical
properties that are relevant to the project considered and
assessing the risks posed by site conditions.
designing earthworks and structure foundations and
monitoring site conditions, earthwork and foundation
construction.

4. HISTORY :
1) Knowledge of the use of soil extends into prehistoric
times, when man started constructing dwellings for
living and roads for transportation.
2) Humans have historically used soil as a material for
flood control, irrigation purposes, burial sites,
building foundations and as construction material
for buildings.
3) Classical geotechnical mechanics began in 1773 with
Charles Coulomb's introduction of mechanics to soil
problems.

5.  APPLICATIONS :
The civil engineer has many diverse important
encounters with soil. some of the applications are
prescribed below.
1) FOUNDATION DESIGNING
Foundation is a very important
element of all civil engineering
structures. All civil engineering
structures like buildings, dams,
bridges, retaining walls, walls,
canals, tunnels or pillars are
founded in or on the surface of
the earth. it is necessary to understand the bearing
capacity of the soil, effect of
ground water and vibration.

6. 2) PAVEMENT DESIGN :
pavement: Cover with a material such as stone or
concrete to make suitable for vehicle traffic
Pavement can be either flexible or rigid, and its
performance depends upon the subsoil on which it
rests.
the thickness of pavement and its component parts
depends upon certain characteristics of the subsoil,
which should be determined before the design is
made.

7. 3) Design of earth-retaining structures and
under ground :
1) The design and construction of underground and
earth-retaining structures constitute an important phase of
engineering.
2) The underground structures include tunnels, underground
buildings, drainage structures and pipelines. A thorough
knowledge of geotechnical engineering is essential to design
gravity-retaining walls, tunnels, underground buildings, etc.
subjected to soil loadings.

8. Design of embankments and excavations :
1) When the surface of the soil structure is not horizontal, the
component of gravity tends to move the soil downward, and
may disturb the stability of the earth structure.
2) The possibility of seeping groundwater reducing the soil
strength while excavating must also be taken into account.
Sometimes, it is required to drain the subsoil water to
increase the soil strength and to reduce the seepage forces.
3) Deep excavation requires lateral braces and sheet walls to
prevent caving in.

9. Design of earth dams :
1) The construction of an earth dam requires a very thorough
knowledge of geotechnical engineering.
2) As soil is used as the only construction material in an earth
dam, which may be either homogeneous or of composite
section.
3) its design involves the determination of the physical
properties of soil such as the index properties, such as
density, plasticity characteristics and specific gravity, particle
size distribution and gradation of the soil etc.,

10. Investigations on geo-technical
engineering can include assessment
of the risk to humans, property and
the environment from natural
hazards, such as earthquakes,
landslides, sinkholes, soil
liquefaction, debris flows and rock
falls.

11.  Failures without considering geo-technical
engineering.
One of he example is:
1) Shrinkage of roads , buildings and other civil
engineering structures.

12.  Conclusion :
By knowing about the geo-technical
engineering we can improve the
durability of any civil engineering
structures.

13. THANK YOU

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