1. Sub. :- Advance Construction Technology
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PREPARED BY:-
Dushyant H. Chhatrola
PREPARED BY :- DUSHYANT H. CHHATROLA
2. Flow of Presentation
Introduction
Uses of pile
Selection of type of piles
Pile cap and Pileshoe
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PREPARED BY :- DUSHYANT H. CHHATROLA
3. Introduction
Foundations are divided in two parts:
1. deep foundation
2. Shallow foundation
If the desired soil bearing capacity is not
available at shallow depth the foundation
of the structure is to be taken to more
depth.
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.
Piles are relatively long and slender
members of wood, steel and concrete
which are used to transmit foundations
loads through soil strata of low bearing
capacity to deeper soil or water logged soil
or made up soil.
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PREPARED BY :- DUSHYANT H. CHHATROLA
4. Use of Pile
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.
The load coming from the structure is very heavy and the distribution of
load on soil is uneven.
They are also used in normal ground conditions to resist heavy uplift
forces or in poor soil conditions to resist horizontal loads.
The pumping of subsoil water is too costly for keeping the foundation
trench in dry condition.
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PREPARED BY :- DUSHYANT H. CHHATROLA
5. Use of Pile
The timbering of excavations is too difficult to maintain the sides of the
foundation trench.
The structures which are situated on sea-shore or river-bed and the
foundation is likely to be affected by the scouring action of water. Thus,
piles are useful for marine structures.
The piles are used as fender piles in the construction of docks ,piers and
other marine structures. A fender pile protects the berthing ships from
damage.
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PREPARED BY :- DUSHYANT H. CHHATROLA
6. Factor Affecting selection of piles
Location and type of structures
Ground condition
Durability
Cost consideration
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PREPARED BY :- DUSHYANT H. CHHATROLA
7. Factor Affecting selection of piles
Location and type of structures:
The location and type of structures may affect the selection of pile type.
e.g. The driven pile or the driven and cast -in -place pile in which the shell
remains in position are the most favoured for works overwater such as
piles in wharf-structures or jetties.
For the structures on land. The driven and cast -in -place types are usually
the cheapest for moderate loadings and unhampered site conditions.
The proximity of existing buildings will also affect the selection of type of
piles, which can be installed without ground vibration; e.g. bored and
cast-in-place piles.
The Jacked piles are suitable types for underpinning existing structures.
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PREPARED BY :- DUSHYANT H. CHHATROLA
8. Factor Affecting selection of piles
Ground condition:
The ground conditions influence both the choice of pile type and the
technique for installing piles.
The driven piles can not be used economically in ground containing
boulders and where ground vibration would be detrimental.
On the other hand, the driven piles are preferred for loose Water-bearing
sands and gravels, where the compaction due to driving can develop the
full potential bearing capacity of these soils.
The steel H-piles, having a low ground displacement, are suitable for
conditions where deep penetration is required in sands and gravels.
The stiff clays favour the adoption of bored and under-reamed types.
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PREPARED BY :- DUSHYANT H. CHHATROLA
9. Factor Affecting selection of piles
Durability
The durability may also affects the selection of pile type.
For piles driven in marine conditions, precast concrete piles maybe
preferred to steel piles from the aspect of resistance to corrosion.
Timber piles may be rejected for marine conditions because of the risk of
attack by destructive borers or insects.
Where soils contain sulphates or other deleterious substances piles
incorporating high-quality precast concrete units preferable to piles
formed by placing concrete in situ in conditions where the presence of
ground water may result in the concrete not being thoroughly compacted.
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PREPARED BY :- DUSHYANT H. CHHATROLA
10. Factor Affecting selection of piles
Cost consideration
The engineer must assess the overall cost of the piling work; e.g. the
resources of the piling contractor to achieve the speed of operations, the
possibility of taking piles to a greater depth that depth shown in
contractor's quotation, the experience of the piling contractor in
overcoming possible difficult conditions, the cost of an extensive test
loading programme on site, the cost of the contractor's site organisation
and over heads, etc.
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PREPARED BY :- DUSHYANT H. CHHATROLA
11. Pile Cap and pile Shoe
When the RCC column or any load carrying structural member is
supported on more than one pile, the no. of piles are connected through
a pile cap to distribute the load to the individual piles.
The pile cap consists of a rigid reinforced concrete slab which act
monolithically with the group of piles. The pile below the pile cap should
be arranged symmetrically about the axis of the column, so that the load
from the column is distributed uniformly to all the piles.
It is advisable to ensure that a pile projects atleat by about 10cm. in the
pile cap and the pie cap should be extended beyond exterior piles by 10
to 15 cm. Further, the plinth beams should be provided to interconnect
adjacent pile caps, so as to give stability to the pile structure as a whole.
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PREPARED BY :- DUSHYANT H. CHHATROLA
12. Pile Cap and pile Shoe
The pile shoes are provided at the bottom end of piles to facilitate the
process of driving the piles through hard soil strata.
The pile are made from cost-iron, stool or wrough-iron, which may
prevent the pile from damage and also to make the piledriving easy.
The various types of pile shoes are provided, such as square, wedge-
shaped and round shape, as in fig.
Fig. Various type of Pile Shoes
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PREPARED BY :- DUSHYANT H. CHHATROLA