This document discusses different types of deep foundations, focusing on pile foundations. It describes pile foundations as vertical structural members driven into the ground to transfer structural loads through weak surface soils to stronger deeper soils or bedrock. Piles are classified based on their function as either load bearing, transferring vertical loads through end bearing or friction; or sheet piles, providing lateral soil support. Piles are also classified based on material, including timber, concrete, steel, or composite piles. Driven piles displace soil during installation while bored piles replace soil to form a void that is then filled with concrete. The document provides details on advantages and disadvantages of different pile types.

1. LECT 6:
DEEP
FOUNDATION
BSR402: BUILDING
CONSTRUCTION AND
MATERIALS I
JULAIDA KALIWON,PHD

2. INTRODUCTION
Deep foundation is required to carry loads from a
structure through weak compressible soils or fills on to
stronger and less compressible soils or rocks at depth, or
for functional reasons.
Deep foundations are founded too deeply below the
finished ground surface for their base bearing capacity to
be affected by surface conditions, this is usually at
depths >3 m below finished ground level.
Deep foundation can be used to transfer the loading to a
deeper, more competent strata at depth if unsuitable
soils are present near the surface.

3. WHY DO WE NEED DEEP FOUNDATION?
IT IS USED WHEN THE
SOIL HAS A LOW
BEARING CAPACITY
IT IS SUITABLE WHEN
THE SELF-WEIGHT OF
THE STRUCTURE IS VERY
HIGH
TO SUSTAIN THE HIGH-
RISE STRUCTURE FROM
THE SUDDEN IMPACT, A
DEEP FOUNDATION IS
THE MOST PREFERABLE
MOSTLY USED WHERE
THE SOIL IS VERY LOOSE
AND LOW DENSE

4. TYPES OF DEEP
FOUNDATION
The types of deep foundations in general use
are as follows:
1. Basements
2. Buoyancy rafts (hollow box foundations)
3. Caissons
4. Cylinders
5. Shaft foundations
6. Pile foundations
For BSR402 the discussion is focused on pile
foundation only. No 1 to 5 will be discussed
on BSR602.

5. PILE
FOUNDATION
In this type of foundation, the load
is transmitted by a vertical
member. This vertical member is
known as a pile. These piles are
generally made of steel, concrete
and wooden. These days precast
members are used but we can
create these members on site as
well.

6. Classification Of
Pile Foundation
According to function
According to material
and construction
methods

8. BASED ON FUNCTION

9. Sheet Piles
This type of piles is mostly used to provide lateral
support. Usually, they resist lateral pressure from
loose soil, the flow of water, etc. They are usually
used for cofferdams, trench sheeting, shore
protection, etc. They are not used for providing
vertical support to the structure. They are usually
used to serve the following purpose-
•Construction of retaining walls.
•Protection from river bank erosion.
•Retain the loose soil around the foundation
trenches.
•For isolation of foundation from adjacent soils.
•For confinement of soil and thus increase the
bearing capacity of the soil.

10. SHEET PILES

11. Load Bearing
Piles
This type of building pile foundation is mainly
used to transfer the vertical loads from the
structure to the soil. These load-bearing pile
foundations transmit loads through the soil with
poor supporting property onto a layer that is
capable of bearing the load. Depending on the
mechanism of load transfer from pile to the soil,
load-bearing piles can be further classified as
flowed.

12. End Bearing
Piles
A load bearing pile is the type
of pile foundation that
transfersthe vertical loads of
the structureto the underlying
soil by either an end-bearing
mechanism or by frictional
mechanism.

13. END BEARING
PILES
1. End-bearing piles develop most of their load-bearing
capacityat the toe of the pile, bearing on a hard layer of
rock or very dense soil and gravel. The pile transmitsthe
load throughsoft, compressible stratadirectlyonto firm
strata.This type of pile thereforeacts in the same way as
a column.
2. Mostof new developments are on reclaimed land used
end bearing piles.
3. These piles transfertheir load on to a firm stratumlocate
data considerabledepth below the base of the structure
and they derive most of their carryingcapacity from the
penetrationresistanceof the soil at the toe of the pile.
4. The founding depth of the pile is influenced by the
results of the site investigationand soil test. The pile
behaves as an ordinary column and should be designed
as such.ie; even in weak soil a pile will not fail by
buckling.

14. Friction or
Cohesion Piles
◦ Friction piles work more like a wedge in the soil. These piles,
also called floating piles, earn most of their bearing capacity by
shear stresses along the sides of the pile, and they are best
used in instances where the hard underlayers of soil are too
deep to efficiently reach.
◦ Friction piles transmit the load from the loose topsoil above to
the soil below by adhesion or friction between the surface of
the pile and the soil. In other words, the friction of the soil
around the pile is what holds the steel pile in place.
◦ Carrying capacity is derived mainly from the adhesion or
friction of the soil in contact with the shaft of the pile.
◦ Load is transmitted to the soil through friction or cohesion. But
sometimes, the soil surrounding the pile may adhere to the
surface of the pile and causes "Negative Skin Friction“ on the
pile.
◦ This, sometimes have considerable effect on the capacity of the
pile. Negative skin friction is caused by the ground water and
consolidation of the soil.

15. Friction or Cohesion
Piles
◦ These piles also transfer their load to the groundthrough
skin friction. The process of driving such piles does not
compactthe soil.
◦ These types of pile foundationsare commonly known as
floating pile foundations
◦ These piles transmitmost of their load to the soil through
skin friction. This processof driving such piles close to each
other in groups,greatly reduces the porosityand
compressibility of the soil within and around the groups.
Therefore,piles of this categoryare sometimes called
compactionpiles.
◦ During the process of driving the pile in to the ground, the
soil becomes moulded and, as a result loses some of its
strength.Therefore,the pile is not able to transferthe exact
amount of load which it is intended to immediately after it
has been driven. Usually, the soil regains some of its
strengththree to five monthsafter it has been driven.

16. Comparison end bearing and friction piles

18. End Bearing vs Friction
Piles

19. Soil Compactor
Piles
Unlike other pile foundation types, this type
of pile does not carry any direct loads. This
type of piles is driven at placed closed
intervals to increase the bearing capacity of
soil by compacting.

20. BASED ON MATERIALS AND
CONSTRUCTION METHOD

21. BASED ON MATERIALS
AND CONSTRUCTION
METHOD
Classification of pile with
respect to effect on the soil
or Method of Installation:
1 driven pile
(displacement piles) or
2 Bored/drilled
piles(replacement piles)

22. Driven Pile foundations
Foundations consistingofvertical structural members that are forced into
the ground byimpact (from a machine called a "piled river").
Prefabricated piles are driven into the ground usinga pile driver plant.
Driven piles are either timber/wood,concrete, orsteel.
Concrete piles are available in square, octagonal,and roundcross-sections.
They are reinforced with rebarand are often pre-stressed.Steel piles are
either pipe piles or some sort of beamsection (like an H-pile).
Piles were spliced together when the design length was too large for a
single pile; today,splicingis onlycommon for timber and steel piles,though
concrete piles can be spliced with difficulty

23. Displacement
Piles
Driven piles are considered
to be displacement piles. In
the process of driving the pile
into the ground, soil is
moved radically as the pile shaft
enters the ground. There may
also be a component of
movement of the soil in the
vertical direction.
Driving piles, as opposed to
drilling shafts, is advantageous
because soil is displaced as the
pile is driven which causes
greater side friction on the
pile (thus increasing its
bearing capacity)

24. Timber Piles
Timber piles are the types of piled foundations that
are placed under the water level. They last for
approximately about 30 years. They can be
rectangular or circular in shape. Their diameter or
size can vary from 12 to 16 inches. The length of the
pile is usually 20 times the top width.
They are usually designed for 15 to 20 tons.
Additional strength can be obtained by bolting fish
plates to the side of the piles.

25. Timber piles

27. Advantages of
Timber Piles
Timber piles of regular size are available.
Economical.
Easy to install.
Low possibility of damage.
Timber pile footings can be cut off at any desired length
after they are installed.
If necessary, timber piles can be easily pulled out.

28. Disadvantages of
Timber Piles
•Piles of longer lengths are not always available.
•It is difficult to obtain straight piles if the length is short.
•It is difficult to drive the pile if the soil strata are very
hard.
•Spicing of timber piles is difficult.
•Timber or wooden piles are not suitable to be used as
end-bearing piles.
•For the durability of timber piles, special measures
have to be taken. For example- wooden piles are often
treated with preservatives.

29. Concrete Piles
Pre-cast Concrete Pile
The precast concrete pile foundation is cast
in a pile bed in horizontal form if they are
rectangular in shape. Usually, circular piles
are cast in vertical forms. Precast piles are
usually reinforced with steel to prevent
breakage during their mobilization from the
casting bed to the location of the foundation.
After the piles are cast, curing has to be
performed as per specification. Generally
curing period for pre-cast piles is 21 to 28
days.

30. Pre-cast concrete pile

31. Pre-cast concrete pile

32. Advantages
of Pre-cast
Piles
•Provides high resistance to chemical and biological cracks.
•They are usually of high strength.
•To facilitate driving, a pipe may be installed along the center
of the pile.
•If the piles are cast and ready to be driven before the
installation phase is due, it can increase the pace of work.
•The confinement of the reinforcement can be ensured.
•The quality of the pile can be controlled.
•f any fault is identified, it can be replaced before driving.
•Pre-cast piles can be driven under the water.
•The piles can be loaded immediately after it is driven up to
the required length.

33. Disadvantages of Pre-
cast Piles
•Once the length of the pile is decided, it is difficult to
increase or decrease the length of the pile afterward.
•They are difficult to mobilize.
•Needs heavy and expensive equipment to drive.
•As they are not available for readymade purchase, it can
cause a delay in the project.
•There is a possibility of breakage or damage during the
handling and driving of piles.

34. Concrete
Piles
Cast-in-Place Concrete Piles
This type of pile footing is
constructed by boring soil up to the
desired depth and then, depositing
freshly mixed concrete in that place
and letting it cure there. cast in situ
concrete pile foundation is
constructed either by driving a
metallic shell to the ground and
filling it with concrete and leaving
the shell with the concrete or the
shell is pulled out while concrete is
poured. Usually, round piles are
used in cast-in situ piling.

35. Replacemet Piles
Bored piles (Replacement piles) are generally
considered to be non- displacement piles. A void is
formed by boring or excavation before piles is
produced. Piles can be produced by casting concrete in the
void.
Some soils such as stiff clays are particularly enable to
the formation of piles in this way, since the bore hole walls
do not requires temporary support except to the ground
surface. In unstable ground, such as gravel the ground
requires temporary support from casing or bentonite slurry.
Alternatively, the casing may be permanent but driven into
a hole which is bored as casing is advanced. A different
technique, which is still essentially non-displacement, is to
intrude, a grout or a concrete from an auger which is
rotated into the granular soil, and hence produced a
grouted column of soil.

36. Replacement
Piles – bored
piles

37. Advantages of Cast-in-
Place Concrete Piles
Foundation
•The shells are light weighted, so they are easy to handle.
•The length of piles can be varied easily.
•The shells may be assembled at sight.
•No excess enforcement is required only to prevent
damage from handling.
•No possibility of breaking during installation.
•Additional piles can be provided easily if required.

38. Disadvantages of Cast-
in-Place Concrete Piles
•In this type of pile foundation, installation requires
careful supervision and quality control.
•Needs sufficient place on site for storage of the
materials used for construction.
•It is difficult to construct cast in situ piles where the
underground water flow is heavy.
•The bottom of the pile may not be symmetrical.
•If the pile is un-reinforced and uncased, the pile can
fail in tension if there acts an uplifting force.

39. Steel Piles
Steel piles may be of I-section
or hollow pipe. They are filled
with concrete. The size may
vary from 10 inches to 24
inches in diameter and the
thickness is usually ¾ inches.
Because of the small sectional
area, the piles are easy to
drive. They are mostly used as
end-bearing piles.

40. Steel Piles

41. Advantages
of Steel
Piles
•They are easy to install.
•They can reach a greater depth compared to any
other type of pile foundations.
•Can penetrate through the hard layer of soil due to
the less cross-sectional area.
•It is easy to splice steel piles
•Can carry heavy loads.

42. Disadvantages of Steel Piles
This piling type
is prone to
corrosion.
Has a possibility
of deviating
while driving.
Comparatively
expensive.

43. Basic
formation
of pile
groups

44. Pile cap

45. Specialty piles
Micropiles
Sheet piles
Soldier piles
Caisson Foundation
Mat Foundation
Spread Foundation
Load Bearing Wall Foundation

46. Task
GET AS MUCH INFORMATION AS POSSIBLE ABOUT
SPECIALTY PILES

47. THANK YOU