Foundation
Foundation is the lowest part of the building
structure, which is directly in contact with the ground and provide the base
for the superstructure and transmits the load to the sub-soil. The structure is
not visible in a complete building because the portion of structure is below
the ground level.
structure, which is directly in contact with the ground and provide the base
for the superstructure and transmits the load to the sub-soil. The structure is
not visible in a complete building because the portion of structure is below
the ground level.
Sub-soil:-
The soil which is located just below the base of the
foundations called the sub soil or foundation soil.
foundations called the sub soil or foundation soil.
Footing:-
The lower portion of the foundation which is in
direct contact with the sub-soil is called footing.
direct contact with the sub-soil is called footing.
Function
of Foundation
·
It transmits the dead load, live load
& wind load from a building from a building to the soil without causing
cracks in the superstructure.
It transmits the dead load, live load
& wind load from a building from a building to the soil without causing
cracks in the superstructure.
·
It provides the level surface for
building operation
It provides the level surface for
building operation
·
It prevent from differential settlement
of the structure
It prevent from differential settlement
of the structure
·
It also provides stability to the
structure
It also provides stability to the
structure
Types of Foundation:-
There are two types of foundation. They are
(i)
Shallow Foundation
Shallow Foundation
(ii)
Deep Foundation
Deep Foundation
(i) Shallow Foundation :- In this type of the foundations the
depth is equal to or less than its width, it is called shallow foundation. In
this type of the foundation the foundation is placed immediately below the
lowest part of the structure.
depth is equal to or less than its width, it is called shallow foundation. In
this type of the foundation the foundation is placed immediately below the
lowest part of the structure.
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| shallow foundation |
Classification of Shallow Foundation
(a) Spread
footing : Spread footing consists of a
wide base of foundation for transmitting the load to the soil over a wider
area.
footing : Spread footing consists of a
wide base of foundation for transmitting the load to the soil over a wider
area.
(b) Combined
footing : Combined footing consists of a common footing provided to two
columns which may be either rectangular or trapezoidal
footing : Combined footing consists of a common footing provided to two
columns which may be either rectangular or trapezoidal
(c) Mat
or Raft Foundation : Raft foundation consist of dense reinforced concrete slab
which covers the total bottom area of the structure. It is provided in the soil
with low bearing capacity where the structural loads are heavy.
or Raft Foundation : Raft foundation consist of dense reinforced concrete slab
which covers the total bottom area of the structure. It is provided in the soil
with low bearing capacity where the structural loads are heavy.
(ii) Deep foundation : A deep foundation is a type
of foundation in which the foundation is placed at a deeper depth below the
ground level. The depth of foundation is much greater than its width.
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| Deep Foundation |
Classification
of the Deep Foundation :
of the Deep Foundation :
(a) Pile
Foundation : Pile foundation is a type of foundation where a slender member of
wood or concrete or steel is inserted into the ground for transferring the load
of a structure. The load is transferred to a stronger stratum by friction.
Foundation : Pile foundation is a type of foundation where a slender member of
wood or concrete or steel is inserted into the ground for transferring the load
of a structure. The load is transferred to a stronger stratum by friction.
Classification
of Pile foundation :
of Pile foundation :
On the
basis of function :
basis of function :
1.
Bearing piles
Bearing piles
2.
Friction piles
Friction piles
3.
Sheet piles
Sheet piles
4.
Anchor piles
Anchor piles
5.
Batter piles
Batter piles
6.
Fender piles
Fender piles
On
the basis of Material
the basis of Material
1.
Timber piles
Timber piles
2.
Concrete piles
Concrete piles
3.
Steel piles
Steel piles
COFFERDAMS : A cofferdams is a temporary structure
which excludes the water from a given site to enable the construction on a dry
surface.
Classification Of Cofferdams on the basis of
material :
material :
1.
Earthen Cofferdam
Earthen Cofferdam
2.
Rock-fill Cofferdam
Rock-fill Cofferdam
3.
Single-walled Cofferdam
Single-walled Cofferdam
4.
Double – walled Cofferdam
Double – walled Cofferdam
5.
Crib Cofferdam
Crib Cofferdam
6.
Cellular Cofferdam
Cellular Cofferdam
Caisson
Foundation : Caisson is watertight structure made of wood, steel or reinforced
concrete which excavates for the foundation of bridges, piers, etc
Types
of Caissons :
of Caissons :
1.Open
Caisson
Caisson
2.
Box Caisson
Box Caisson
3.
Pneumatic Caisson
Pneumatic Caisson