1) Pile foundations transfer structural loads deep into the ground through vertical piles that can be made of timber, concrete, or steel. 2) Piles are used when shallow foundations are not suitable due to deep bearing strata or poor soil conditions near the surface. 3) Piles are classified by their function as end bearing, friction, or a combination, and by material as concrete, steel, timber, etc. Proper pile spacing and group efficiency are considered for pile group design.

1. S.N.P.I.T. & R.C.
UMRAKH
Pile Foundation
Assis. Professor Neetu Yadav

2. Presentation By
Mehta Mrunali- 130490106064
Modi Nagma- 130490106065
Nakrani Akash- 130490106066
Nikam Sejal- 130490106067

3. Pile Foundation

4. Contents:
-Introduction
-Uses of pile
-Selection of type of pile
-Types of pile
-Pile spacing
-Group of piles
-Efficiency of group of pile
-Pile hammer
-Micro piling
-Causes of failure of piles

5. Introduction:
Pile foundations are divided in two parts:
1. deep foundation
2. Shallow foundation
Pile foundation is that type of foundation in which
the loads are taken to a law level by means of
vertical members which may be of timber, concrete ,
or steel.

6. Uses of piles:
-Pile foundation is generally used when simple spread
foundation at a suitable depth is not possible either
because the stratum of required bearing capacity is at a
greater depth are encountered.
-piles are used for foundation for building, bridges, and
water front installation.
-They are also used for structures in the area where
canals, deep drainage lines, etc.
Factor affecting selection of piles:
1. Location and type of structures.
2. Ground condition
3. Durability
4. Cost consideration

7. Classification of piles based on their
functions:
1. End bearing piles
2. Friction pile
3. Compaction pile
4. Tension pile
5. Anchor pile
6. Fender pile
7. Better pile
8. Sheet pile

8. End bearing piles:
 If the piles are driven into the ground until a hard
stratum is reached and the piles act as a pillars
supporting the super structure and transmitting the load
to the hard ground.

9. Friction pile
 When loose soil extended to a great depth, pile are
driven up to a such a depth that frictional resistance
developed at the sides of the piles equals the load
coming on the piles

11. Fender pile:
 Fender piles are used to protect water front
structure against impact from ships or other floating
objects.

12. Sheet pile:
 They are used to bulk heads or as impervious cutoff
to reduce seepage and uplift under hydraulic
structure.

13. Depending upon the materials used in
construction of load bearings piles are
classified as:
•Cast iron pile
• Cement concrete pile
1.Pre cast piles
2.cast-in-situ piles
3. Prestressed concrete piles
• Sand pile
• Steel pile
• Timber pile
•Wrought-iron pile

14. Precast pile:
 Precast concrete piles are those which are
manufactured in a factory or at a place away from
the construction site, and then driven into the
ground at the place required.

16. Cast-in-situ concrete piles:
 In this type of concrete piles, a bore is dug into the
ground by inserting. This bore is then filled with
cement concrete after placing reinforcement, if any.

17. Common types of uncased cast-in-situ
piles:
1. Simplex piles
2. Franki piles
3. Vibro piles
4. Pedestal piles
5. Pressure piles

18. Pedestal piles:
 This type of piles are used where thin bearing
stratum is reached with reasonable depth. The
pedestal of the pile gives the effect of spread
footing on this comparatively thin bearing.

19. Franki pile:
 In this type of pile, a plug of dry concrete gravel is
formed on the ground by heavy removable pipe
shell.

20. Timber pile:
 Thee piles are prepared from trunks of trees. They
may be circular or square. They are 30 to 50 cm in
diameter with a length not exceeding 20 times its
top.

21. Sand piles:
 These piles are formed by making holes in the
ground and then filling them with sand. If sand is
kept confined, it possesses great crushing strength
and becomes incompressible.

22. Non-Load Bearing pile:
This type of piles are used as a separating members
below ground level and they are generally not designed to
take any vertical load.
•Purpose:
-To isolate foundation from adjacent soil.
- To construct retaining wall in docks, wharfs etc.
-To protect river banks.
-Intake supplies.

24. Under-reamed pile:
- The under reamed pile provide an ideal solution to
foundation in black cotton soil or other similar type of
expansive soil.
A pile having one bulb at a base is known as a single
under reamed pile.
A load bearing capacity of pile can be increased by
increase in the number of bulb at the base.
The diameter of an under reamed pile varies from 20 cm
to 50 cm. And bulb diameter varies from 2 to 3 times the
diameter of pile

26. Method of construction:
-The equipment for the construction of pile consists of
auger boring guide, spiral auger with extension road,
under-reamer with bucket and concreting funnel etc.
-The auger should be rotated slowly with a constant
downward pressure and taken out when it is full with soil.
-The holes for casting pile in the ground may be bored by
using hand augers.
-For deeper borings , the length of the auger can be
increased by adding suitable extension rods or pipes.
-In sites where the sub soil water table is high, bentonite
slurry are used to retain the sides of the bore hole against
collapse.
-After the pile holes are ready for concreting , the
reinforcement cages are lowered in the holes and concrete
is poured by the use of funnel.

27. Pile spacing:
The spacing of the pile is the centre to centre distance
between two successive piles.
Factors:
-The nature of soil through which the pile is driven.
-The obstructions during pile driving.
-The type of pile.
-The area of cross section.
-The depth of penetration.
-The centre to centre distance of pile in a group.
-The material of pile.

28. Group of piles:
Sometimes the piles are arranged in close spaced group.
when the piles are driven to the required depth, their tops
are cutoff to a same level and then the pile cap is provided as
in figure.

30. - The piles are forming the group of pile may be arranged in
square, rectangular, triangular or circular as per the
requirement
- In case of single pile, a small pressure is developed in the
surrounding soil.
- The bearing capacity of a pile group may not be
necessarily equal to the sum of the bearing capacity of
individual piles forming a group.
- The cost of friction pile, the centre to centre distance
between successive piles should be 105cm. or the perimeter
of the pile, whichever is greater.

31. Efficiency of group of pile:
The efficiency of a pile group is taken as the ratio of the
average load per pile, When the failure of group occurs to
the load at failure of a comparable single pile.
It is determined by two methods:
•converse Labbore equation.
•Field rule.

33. PILE HAMMER:
1.Drop hammer:
The drop hammer in the pile driving equipment
consists of a heavy ram in between the leads. The
ram is lifted up to a certain height and released to
drop on the pile. This type is slow and therefore not
in common use

34. 2. Single acting hammer
 In a single acting hammer a heavy ram is lifted up
by steam or compressed air but dropped by its own
weight. The energy of a single acting hammer is
equal to the weight of the ram times the height of
fall.
3. Double acting hammer:
 The double acting hammer employs steam or air for
lifting the ram and for accelerating the downward
stroke. The energy of a double acting hammer is
equal to weight of ram or effective pressure of 1
times the height of fall.

35. 4. Diesel hammer:
 The diesel hammer is a small, light weight and
highly mobile. They use gasoline for fuel. To start
the operation, the ram is raised, and the fuel is
injected. As the ram released, the ram falls and
compressed air and fuel.

36. Micro piling:
 Micro piling is to the demand for innovative
techniques for underpinning historic buildings and
mounments that has sustained damage with time.
The micro piling systems used today are evolution
from the basic small diameter, cast-in-situ pile.

38. Causes of failure of piles:
 Absence of statistical data regarding the nature of soil
strata through which the piles are to be driven.
 Actual load coming on the pile being more than the
design.
 Bad workmanship in case of the cast-in-situ cement
concrete piles.
 Attack by insects, etc. on wooden piles.
 Breakage due to over driving especially in case of the
timber piles.
 Buckling of piles due to removal of side support,
inadequate lateral supports, etc.
 Improper choice of the pile.
 Pressure of soft strata just below the tips of piles.
 Improper choice of the method of the driving the pile.