This document discusses different types of foundations. It describes shallow foundations, which are placed immediately below the structure and distribute loads over a wide area near the surface. Spread footings, combined footings, and mat/raft foundations are types of shallow foundations. Spread footings are used to support columns and walls. Combined footings support two or more closely spaced columns. Mat foundations consist of a thick concrete slab covering the entire bottom of the structure. The document also outlines some limitations and advantages of shallow foundations.

1. Done by:
Aditya Raj Pradhan BE/10575/2014
Rishikesh Prabhakar BE/10667/2014

2.  Lowest part of a structure
 Provides a base for the super structure
 Transmits the load on the structure including the dead
weight of the structure itself to the soil below.
Foundation

3. 
Deep foundations
Shallow foundations
Types of Foundation:

4. 
 Foundation placed immediately lowest part of the
super structure.
 Used to distribute the structural load over a wide
horizontal area at a shallow depth below the ground
level.
 According to Terzaghi, a foundation is shallow if its
depth is equal to or less than its width.
Shallow Foundation

5. 
 Spread footing
 Combined footing
 Mat or raft footing
Types of Shallow
Foundations

6.  Structural members are used to support columns and
walls and to transmit their loads to their loads to the
soil.
Spread footing

8. 
 Wall footings
 Reinforced Concrete footings
 Inverted arch Footing
 Column Footings
Types of Spread footing

9. 
Wall footing
 Supports wall that may
either be bearing or non
bearing walls.
 Required to support
direct concentric loads.
 Used in low rise
buildings.

10. 
Reinforced Concrete
Footing
 Relatively heavy
loading than wall
footing.
 Bearing capacity of soil
is low.
 Reinforcing steel is
placed in the bottom of
the footing in a
direction perpendicular
to the wall.

11. 
Inverted arch footing
 Used to resist sideways,
inwards loads.
 Used in conjunction
with retaining walls.

12. 
Column Foundation
 Most economical type
of footing
 Used when columns are
spaced at relatively
long distances.
 Carries heavy load
 Used to support single
column.
 Distribute the load
uniformly.

13. 
 Usually supports two or three columns not in a row.
 Used when two columns are so close that single
footings cannot be used or when one column is
located at or near a property line.
Combined footings

14. 
Combined Footing
 Two columns are close
together causing
overlap of adjacent
isolated footings.
 Soil bearing capacity is
low causing overlap of
adjacent isolated
footings.

15. 
Procedure of Combined
Footing

16. 
 Consist of a thick reinforced concrete slab covering
the entire area of the bottom of the structure (like a
floor).
Raft/ Mat Foundation

17. 
 Base soil has low bearing capacity or
 Column load are so large that more than 50% of the
area covered by conventional spread footing.
 Resist unequal settlement due to earthquake.
 Quickness of construction work.
Raft Foundation

18. 
Different types of Raft

19.  Spread footers being installed is too shallow (2-3 feet below), which
does not eliminate the effects of expansive soil.
 Foundation repair will last longer than a week as the excavations
are made and the concrete will have to be cured before the holes can
be refilled.
 A huge amount of earthwork is to be done in mat foundation
 If the shoring system cannot resist the pressure of outside land, then
the structure surrounding the area may be damaged by deflection of
soil.
 Ground water may come out when earthwork is done.
 Limited to dealing with point loads.
Limitations of Shallow
Foundation

20. 
 Quick process compared to others construction
work.
 Economically cheaper.
 Can resist ground water absorption.
 Damage due to earthquake is lesser than any other
type of foundation.
 Consist of reinforced concrete slab which is more
thicker than footing foundation.
 Prevents unequal settlements.
Advantages of shallow
foundation