Foundation and its types and detailed explanation

FOUNDATION AND ITS TYPES DETAIL EXPLANATION FOR BUILDING MATERIAL CONSTRUCTION AND PLANNING

1. FOUNDATION AND ITS TYPES

2. COURSE OBJECTIVE:
•To differentiate between shallow and deep
foundation.

3. FOUNDATIONS
•The substructure or foundations is the lower portion of the
building, which is usually located below the ground level,
which transmits the load of the superstructure to the subsoil.
PURPOSES OF FOUNDATION:
•To distribute the load of the structure over a large bearing area.
• The load bearing surface at a uniform rate, as to prevent
unequal settlements of soil.
• To secure a level and firm bed for building
operations.

4. TYPES OF FOUNDATIONS:
Foundations can be broadly classified into following:
1.Shallow foundations
2.Deep foundations

5. 1.Shallow foundation:
• The foundations provided immediately underneath the
lowest part of the structure, near to the ground level.
•The object of this type of foundation is to distribute the
structural loads over a considerable base area at the
foundation bed.

7. 2. Deep foundations:
The foundation constructed sufficient below ground level with
some artificial arrangements such as piles, wells etc at their
base.
Classified as following:
i.Pile foundations
ii.Well foundations
iii.Caisson foundations.

8. i. Pile Foundation:
•A pile is basically a long cylinder of a strong material such as
concrete that is pushed into the ground to act as a steady support for
structures built on top of it.
•Pile foundations are used in the following situations:
•When there is a layer of weak soil at the surface. This layer cannot
support the weight of the building, so the loads of the building have
to bypass this layer and be transferred to the layer
of stronger soil or rock that is below the weak layer.
When a building has very heavy, concentrated
loads, such as in a high rise structure, bridge, or
water tank.
•

10. ii. Well foundation:
•Well foundation is a type of deep foundation which is generally
provided below the water level for bridges.
•Cassions or well have been in use for foundations of bridges and
other structures since Roman and Mughal periods.
•The term ‘cassion’ is derived from the French word caisse which
means box or chest.
• Hence cassion means a box like structure, round or rectangular,
which is sunk from the surface of either land or water
to some desired depth.

12. COURSE OUTCOMES
•Able to differentiate different types of
foundations.