2. Outline
• Introduction
• Pile foundation
• Steel H-Piles
• Concrete piles
• Timber Piles
• Classification of piles based on function
• Pile cap reinforcement
• Selection of Pile
• Uses of pile foundations
3. Introduction
• Our building is rested on a weak soil formation which can’t resist the
loads coming from our proposed building, so we have to choose pile
foundation.
5. Steel H-Piles
Steel piles first came into use in the 1890's
Typical lengths 50 to 150 feet.
Typical design loads 45 to 225 tons.
ADVANTAGES
Available in Various Lengths and Sizes. Especially useful for tension
and uplift loads.
Easy to Splice.
High Capacity.
Low Soil Displacements.
May Penetrate Larger Obstructions with Driving Shoes.
Remarks Best Suited for Toe Bearing on Rock.
6. DISADVANTAGES
• Vulnerable to Corrosion.
• Not Recommended as Friction Pile in Granular Soils.
• Expensive compared to other piles
• May be subject to corrosion, depending upon soil
and water conditions
Steel H-Piles
7. Concrete piles
Usual length: 10m-20m
Usual load: 300kN-3000kN
Advantages
Corrosion resistance
Can be easily combined with a concrete
superstructure
Disadvantages
Difficult to achieve proper cutoff
Difficult to transport
8. Timber Piles
• The oldest type of pile in use.
• Most used today are Southern Pine or Douglas Fir.
• Diameters range from 6" –18”
• Lengths from 20' – 60’
• Inexpensive and easy to cut
• Difficult to splice (limited length).
• Limited Bearing Capacity (< 250 KN) usually 100-200 KN (10-20 tons).
• Suitable for soft clay, loose sand and silt.
12. These piles are used to transfer load through water
or soft soil to a suitable bearing stratum.
END BEARING PILE
13. These piles are used to transfer loads to a depth of a friction load
carrying material by means of skin friction along the length of pile.
FRICTION PILE
14. These piles are used to compact loose soils, thus increasing their bearing
capacity. The compaction piles themselves do not carry any load. Hence
they may be of weaker material (sand). The pile tube, driven to compact
the soil, is gradually taken out and sand is filled in its place thus forming
a ‘sand pile’.
COMPACTION PILE
15. • Pile caps carrying very heavy point loads tend to produce high
tensile stresses at the pile cap.
Reinforcement is thus designed to provide:
• Resistance to tensile bending forces in the bottom of the cap
• Resistance to vertical shear
Pile Cap Reinforcement
16. Selection of Pile
Factors governing the selection of piles
Length of the pile in relation to the load and type of soil,
Characters of structure,
Availability of the materials,
Types of loading,
Factors causing deterioration,
Ease of maintenance,
Estimated cost of types of piles, taking into account the initial
cost, life expectancy and cost of maintenance
Availability of funds.
17. Pile foundations are used in the following situations:
The load of the super structure is heavy and its distribution is
uneven
The top soil has poor bearing capacity
The subsoil water level is high
There is large fluctuations in subsoil water level
Canal or deep drainage lines exist near the foundation
The structure is situated on the sea shore or river bed