about classification of pile foundation

1. SARDAR PATEL COLLEGE
OF ENGINEERING
oSUB : FOUNDATION ENGINEERING
oSUB CODE : 2180609
oGUIDED BY : PROF. MAITRY CHAUHAN

2. Sr No. Name Enrollment No.
1 Kanojiya Nilay A. 141240106025
2 Patel Akshar K. 141240106040
3 Prajapati Brijen V. 141240106060

3. CLASSIFICATION OF
PILES

4. Classification Based On Function
o Bearing Piles or End Bearing Piles
o Friction Piles or Skin Friction Piles
o Sheet Piles
o Tension Piles or Uplift Piles
o Anchor Piles
o Batter Piles
o Fender Piles
o Compaction Piles

5. End Bearing Pile
o Driven into the ground until a hard
stratum is reached.
o Acts as pillars supporting the super-
structure and transmitting the load to
the ground.
o Piles, by themselves do not support the
load, rather acts as a medium to
transmit the load from the foundation
to the resisting sub-stratum.

6. Friction Pile
o Piles are driven at a site where soil is weak or soft to a considerable depth and
it is not economical or rather possible to rest the bottom end of the pile on the
hard stratum.
o Load is carried by the friction developed between the sides of the pile and the
surrounding ground (skin friction).
o The piles are driven up to such a depth that skin friction developed at the
sides of the piles equals the load coming on the piles.
o Skin friction should be carefully evaluated and suitable factor of safety
applied, as it is this which is supporting the whole of structure over its head.

7. Friction Pile
o The load carrying capacity of friction pile can be increased by-
1) Increasing diameter of the pile
2) Driving the pile for larger depth
3) Grouping of piles
4) Making surface of the pile rough

8.  Anchor Piles
o Piles are used to provide anchorage against horizontal pull from sheet piling
wall or other pulling forces.
 Batter piles:
o Piles are driven at an inclination to resist large horizontal and inclined forces.
 Fender piles:
o Piles are used to protect concrete deck or water front structures against impact
from ships or other floating objects. Ordinarily made up of timber.
 Compaction piles:
o When piles are driven in granular soil with the aim of increasing the bearing
capacity of the soil, the piles are termed as compaction piles.

10. Classification Based On Materials
o Timber Piles
o Concrete Piles
o Composite Piles
o Steel Piles
o Sand Piles

11. Timber Piles
o Transmission of load takes place by the frictional resistance of ground and the
pile surface.
o Piles made from timber of tree like Sal, Teak, Deodar, Babul, Khair etc.
o Khair piles can stand action of sea water and thus used for marine works.
o May be circular, square in x-section.
o Piles are driven with the help of pile driving machine in which drop hammers
delivers blows on the pile head.
o Brooming of pile head is prevented by providing an iron ring of less than
25mm in diameter than the pile head at the pile top.

12. Timber Piles
o To facilitate driving, the lower end
is pointed and provided with a cast
iron conical shoe.
o Piles should not be spaced less
than 60 cm center to center, the
best spacing is 90 cm c/c. closer
spacing destroys frictional
resistance.
o Diameter varies from 30 to 50cm.
o Length should not be more than 20
times the least sectional dimension.

13. Concrete Piles
o The cement concrete possesses excellent compressive strength. With the
introduction of Reinforced cement concrete, the RCC piles are becoming
more popular and they are fast replacing piles of other materials.
o Concrete Piles are of 3 types:
1. Pre-cast Piles
2. Cast in situ Piles
3. Prestressed Concrete Piles

14. Pre-cast Concrete Piles
o Reinforced concrete piles, moulded in circular, square, rectangular or
octagonal form.
o Cast and cured in the casting yard, then transported to the site of driving.
o If space available it can be cast and cured near the work site.
o Driven in similar manner as timber piles with the help of piles drivers.
o Diameter normally varies from 35cm to 65cm, length varies from 4.5m to
30m

15. Pre-cast Concrete Piles
o Function of reinforcement in a pre-cast pile is to resist the stresses during
handling, driving and final loading on the pile rather than strengthen the pile
to act as a column.
o Longitudinal reinforcements usually 20mm to 50mm in diameter, stirrups
6mm to 10mm in dia.
o For 90 cm length at head and toe, stirrups spacing is 8cm c/c and for
remaining intermediate length it is about 30cm c/c.
o Circular piles are seldom tapered. When tapered piles length is restricted to
12m.
o A concrete cover of 5cm is maintained throughout, over the main steel bars.

16. Cast-in-Situ Concrete Piles
o Cast in position inside the ground.
o First of all a bore is dug by driving a casing pipe into the ground.
o Then the soil from the casing is jetted out and filled with cement concrete
after placing necessary reinforcement in it.
o Cast-in-situ piles are of two types:
1) Cased Cast-in-Situ Piles: metallic shell is left inside the ground along with
the core
2) Uncased Cast-in-Situ Piles: metallic shell is withdrawn