foundation week 4

7/30/2019 Foundation Week 4

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2. FOUNDATIONS CONT DEEP FOUNDATIONS

By- Kokebe Yifru -Adama University Department of Civil Engineering & Arc- 20010/2011


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2. DEEP FOUNDATIONS

Deep foundations are those in which the

depth of the foundation is very large in

comparison to its width.

Constructed sufficiently below ground level

with artificial arrangements such as piles,wells, etc at their base.


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DEEP FOUNDATIONS

Classifications of Deep Foundation:-

1.

Pile foundations (commonly used)

2.

Pier foundation

3.

Caisson or Well foundation

By - Kokebe Yifru -Adama University Department of Civil Engineering & Arc- 2009/2010

Read


5/17

DEEP FOUNDATIONS

A pile FoundationA pile Foundation is that type of deepis that type of deepfoundation in which the loads are taken to afoundation in which the loads are taken to alow level by means of alow level by means of a vertical membersvertical members

which may be ofwhich may be oftimbertimber,, concreteconcrete oror steelsteel

oror combination of themcombination of them..


6/17

DEEP FOUNDATIONS PILE FOUNDATION Pile Foundation is Suitable under the followingPile Foundation is Suitable under the following

situations:situations:--

1. When the soil is very soft and solid base is1. When the soil is very soft and solid base is

not available at reasonable depth to keepnot available at reasonable depth to keep

the bearing capacity within the safe limit.the bearing capacity within the safe limit.

2. The subsoil water level is high so that2. The subsoil water level is high so that

pumping of water from the open trenchespumping of water from the open trenches

for the shallow foundations is difficult andfor the shallow foundations is difficult and

uneconomical.uneconomical.


7/17

DEEP FOUNDATIONS PILE FOUNDATION Suitability of pile Foundation:Suitability of pile Foundation:--

3. Where there is large fluctuations in subsoil3. Where there is large fluctuations in subsoil

water levelwater level

4. Instead of Mat foundation where no firm4. Instead of Mat foundation where no firmbearing strata exists at a reasonable depthbearing strata exists at a reasonable depth

and the loading is uneven.and the loading is uneven.


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PILE FOUNDATION CONT

Suitability Cont..Suitability Cont..

5. When it is necessary to construct a building5. When it is necessary to construct a building

along the sea shore or a river bed.along the sea shore or a river bed.

6. If deep strip foundation is attempted,6. If deep strip foundation is attempted,

timbering of sides is difficult to maintain ortimbering of sides is difficult to maintain orretain the soil of sides of the trench, thusretain the soil of sides of the trench, thus

pile Foundation can be used.pile Foundation can be used.


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ClassificationClassification

1.1.

Based on functionBased on function

End bearing pileEnd bearing pile

Friction pileFriction pile

Compaction pileCompaction pile Tension pile or uplift pileTension pile or uplift pile

Anchor pileAnchor pile

Fender pile and dolphinsFender pile and dolphins

Batter pileBatter pile

Sheet pileSheet pile


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Classification contClassification cont

2. Based on material and composition2. Based on material and composition

1.1.

Concrete pileConcrete pile

a)a)

PrePre--castcast

b)b)

CastCast--inin--situsitu

i) Driven piles: cased or uncasedi) Driven piles: cased or uncased

ii) Board piles: pressure piles,ii) Board piles: pressure piles,

underunder--reamed piles and board compaction pilesreamed piles and board compaction piles

2 . Timber piles2 . Timber piles

3. Steel piles3. Steel piles

4. Composite piles4. Composite piles


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Classification contClassification cont

2.2. Based on material and compositionBased on material and composition

1.1.

Concrete pileConcrete pile

a)a)

PrePre--castcast

b)b) CastCast--inin--situsitu

E.g.. Raymond Standard PileE.g.. Raymond Standard Pile


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CONCRETE PILECONCRETE PILE PREPRE--CASTCAST

PrePre--cast concrete piles may be manufactured in almostcast concrete piles may be manufactured in almost

any desired size or shape.any desired size or shape.

Commonly used section shapes include round, square,Commonly used section shapes include round, square,

and octagonal shapes.and octagonal shapes.

Advantage of concrete piles include high strength andAdvantage of concrete piles include high strength and

resistance to decay. However, a preresistance to decay. However, a pre--cast concrete pile iscast concrete pile is

usually the heaviest type of pile available for a givenusually the heaviest type of pile available for a givenpile size.pile size.


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CONCRETE PILECONCRETE PILE PREPRE--CAST CONTCAST CONT

Because their brittleness and lack of tensileBecause their brittleness and lack of tensile

strength, they require care in handling andstrength, they require care in handling and

driving to prevent pile damage.driving to prevent pile damage.

Since they have little strength in bending, theySince they have little strength in bending, they

may be broken by improper lifting procedures.may be broken by improper lifting procedures.

Cutting requires the use of pneumaticCutting requires the use of pneumatic

hammers and cutting torches or special saws.hammers and cutting torches or special saws.


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CONCRETE PILECONCRETE PILE CASTAST--ININ--SITUSITU CastCast--inin--placeplace

concrete piles are constructed by driving aconcrete piles are constructed by driving a

steel shell into the ground and then filling it withsteel shell into the ground and then filling it with

concrete.concrete.

Usually, a steel mandrel or core attached to the pileUsually, a steel mandrel or core attached to the pile

driver is placed inside the shell to reduce shell damagedriver is placed inside the shell to reduce shell damage

during driving.during driving.

Although straight shells may be pulled as they areAlthough straight shells may be pulled as they are

filled with concrete, shells are usually left in place andfilled with concrete, shells are usually left in place andserve as additional reinforcement for the concrete.serve as additional reinforcement for the concrete.


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CONCRETE PILECONCRETE PILE

CASTCAST--ININ--SITU CONT..SITU CONT.. .. The shells are light, easy to handle, and easyThe shells are light, easy to handle, and easy

to cut and splice.to cut and splice.

Since shells may be damaged during driving,Since shells may be damaged during driving,

they should be Visually inspected before fillingthey should be Visually inspected before filling

with concrete.with concrete.

Shells driven into expansive soils should beShells driven into expansive soils should be

filled with concrete as soon as possible afterfilled with concrete as soon as possible after

driving to reduce the possibility of shelldriving to reduce the possibility of shell

damage due to lateral soil pressure.damage due to lateral soil pressure.


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FOUNDATIONSFOUNDATIONS

Assignment

1.

Enumerate the different types of

A-Deep Foundations

B-

Piles

and describe each type and Specify the

advantages and disadvantages briefly.

2. Explain briefly the causes of failure of foundation

and remedial measures.(max

15 pages)

Summary

By Group 3


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Thank You!!

foundation week 4

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