MULTIDISCIPLINRY NATURE OF THE ENVIRONMENTAL STUDIES.pptx
Driven & Bored Piles
1. Driven and
Bored Piles
MADE BY :
AHMED MOHAMED ZANATY 9103710
AHMED ABDULLAH NEGM 9104441
MOHAMED AHMED EL SAEID 9103644
ABDELRAHMAN MOHAMED 9104286
AHMED YOUSSEF 9100499
DEPARTURE: COURSE:
CONSTRUCTION & BUILDING FOUNDATION
UNDER SUPERVISION OF:
PROF. ADEL BELAL
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2. What is Deep foundation ?
A deep foundation is a type of foundation distinguished from
shallow foundations by the depth they are embedded into the
ground. There are many reasons a geotechnical engineer would
recommend a deep foundation over a shallow foundation, but
some of the common reasons are very large design loads, a poor
soil at shallow depth, or site constraints
There are different terms used to describe different types of deep
foundations including the pile, the pier, drilled shafts, and caissons.
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3. What are Piles ?
Piles are generally driven into the ground in situ; other deep
foundations are typically put in place using excavation and drilling.
The naming conventions may vary between engineering disciplines
and firms. Deep foundations can be made out of
timber, steel, reinforced concrete and pre-stressed concrete.
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4. How piles are connected ?
Foundations relying on driven piles often have
groups of piles connected by a pile cap (a large
concrete block into which the heads of the piles
are embedded) to distribute loads which are
larger than one pile can bear.
Pile caps and isolated piles are typically
connected with grade beams to tie the
foundation elements together; lighter structural
elements bear on the grade beams, while heavier
elements bear directly on the pile cap.
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5. Pile installation
Pile installation is as important as design. There are two methods of
installation :
a)Installation by Driving
b)Installation by Boring
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6. Pile installation
Before going through pile installation methods understand the following terminology.
Driven pre-cast pile: The pile is casted in a yard brought to the site and
driven by some mechanism into the soil.
Driven Cast-in-situ pile: A casing plugged at bottom is driven into the ground
and then the pile is casted by removing or retaining the casing.
Bored Pre-cast pile: A bore is made and the soil inside is removed and then a pile
casted in some yard is put into the bore.
Bored Cast -in-situ pile: A bore is made the soil is removed and the pile is casted at
site in the bore.
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10. Driven Pile installation
All pile driving equipment, including the pile driving hammer,
hammer cushion, helmet, pile cushion, and other appurtenances
to be furnished by the Contractor shall be approved in advance
by the Engineer before any driving can take place.
To obtain this approval, the Contractor shall submit a description of
pile driving equipment to the Engineer before pile driving begin.
The description must contain sufficient detail so that the proposed
driving system can be evaluated by the Engineer.
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11. Hammer Types
Drop hammer / Gravity hammer
Single acting power driven hammer
Double Acting Power Driven Hammer
Diesel Power Driven Hammers
Vibratory and Sonic Power Driven
Hammers
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12. Drop hammer / Gravity hammer: This is the original pile
driving hammer. It consists of a steel ram that is guided
within a set of leads. The hammer is raised to a certain
height and allowed to drop on top of the pile, thus
producing the driving reaction.
Hammer Types
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13. Hammer Types
Single acting power driven hammer: Hammers of this type are
basically power gravity hammers. The difference between a
gravity hammer and a single acting power hammer is that the ram
(striking part) is encased in a steel frame work and is raised by
steam or compressed air rather than by the crane load lines. The
frequency of the blows is also considerably higher than a drop
hammer. The ram mass is usually greater than a drop hammer and
the vertical travel is usually less than that of a drop hammer. Any
type of power hammer is usually more efficient than a drop
hammer because there is less time between blows for the soil to set
up around the pile.
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14. Hammer Types
Double Acting Power Driven Hammer: The ram is raised
by steam or compressed air, as in the case of the single
acting power hammer. When the ram approaches the
top of its stroke a valve is opened into a chamber at
the top of the cylinder allowing high pressure air or
steam into the cylinder forcing the ram downward.
Some double acting hammers utilize a light ram,
operating at a high frequency, to develop the energy
blows comparable to those developed by heavier,
slower acting hammers. The advantage of the lighter
ram hammer is that there is less time between blows for
soil to re-settle against the pile, thus increasing the
driving efficiency and decreasing the drive time.
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15. Hammer Types
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Diesel Power Driven Hammers: They are simply a one
cylinder diesel engine consisting of a steel cylinder
containing a ram and an anvil. The ram is raised initially by
an outside power source (crane) and dropped. As the ram
drops, it activates a fuel pump, which injects fuel into a cup
in the top of the anvil. The ram continues down blocking the
exhaust ports and compressing the air in the combustion
chamber. A ball on the end of the ram, mating closely with
the cup in the anvil, forces the fuel into the hot compressed
air between the ram and the anvil. The fuel then explodes
forcing the ram up and forcing the anvil, and in turn, the
pile down.
16. Hammer Types
Vibratory and Sonic Power Driven Hammers: These are the
most recent developments in pile hammer technology.
They are comparatively heavy, requiring handling
equipment of greater capacity than required for
conventional pile hammers. The Vibratory Hammer vibrates
the pile at frequencies and amplitudes which tend to break
the bond between the pile surface and the adjacent soils,
thus delivering more of the developed energy to the tip of
the pile.
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17. Driven Pile installation
1. Raising the piston (starting)
2. Injection of diesel fuel and
compression
3. Impact and atomization.
4. Exhaust
5. Scavenging
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18. Driven Pile installation
1.Raising the piston (starting): For starting the diesel hammer, the
piston (ram) is raised by means of a mechanical tripping device and is
automatically released at a given height.
2. Injection of diesel fuel and compression: As the piston falls through
the cylinders, it activates a lever on the back of the fuel pump, which
injects a measured amount of diesel fuel on to the top of the impact
block. Shortly after this, the exhaust ports are closed.
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19. Driven Pile installation
3. Impact and atomization: Compressing all the air /fuel between the
exhaust ports and the top Of the impact block, the piston continues
falling until it strikes the top of the impact block. The heat generated
by the compression of air, in the presence of atomized fuel, causes
the explosion of the fuel, throwing the piston upward and forcing the
impact block downward against the pile.
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20. Driven Pile installation
4. Exhaust: While moving upwards, the piston will pass and open the
exhaust ports. Exhaust gases will escape and the pressure in the
cylinder will equalize.
5. Scavenging: The piston continues its upward momentum, which
draws in fresh air for the nextcycle, cools the cylinders, and releases
the pump lever. The pump lever returns to its startingposition, so that
the pump will again be charged with fuel. Gravity stops the upward
motion of thepiston and it starts falling through the cylinders once
again.
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27. Pile installation
Pile installation is as important as design. There are two methods of
installation :
a)Installation by Driving
b)Installation by Boring
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28. Bored Piles
Bored piles is another type of reinforced concrete piles which is
used to support high building which has heavy vertical load. Bored
pile is a cast-in-place concrete pile where the bored piles have to
be cast on construction site.
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29. Bored Piles
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Normally bored piling has be to carried on those tall
buildings or massive industrial complexes, which require
foundations which can bear the load of thousands of
tons, most probably in unstable or difficult soil
conditions. Bored piling is cast by using bored piling
machine which has specially designed drilling tools,
buckets and grabs, it’s used to remove the soil and
rock. Normally it can be drilling into 50metres depth of
soil.
30. Advantage & Disadvantage of Bored
Piles
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Advantage Disadvantage
Absence of vibration will not disturb adjacent
piles or structures.
Susceptible to "wasting" or "necking" in
"squeezing" ground.
Extremely high capacity caissons can be
obtained by expanding the base of the shaft up
to three times the shaft diameter, thus
eliminating construction of caps over multiple
pile groups.
Concrete is not placed under ideal conditions
and cannot be subsequently inspected.
For many design situations bored piles
offer higher capacities with potentially better
economics than driven piles.
Water under artesian pressure may pipe up pile
shaft washing out cement.
32. Bored Pile installation
To install a pile you should drill a borehole of a specified diameter
and depth. Next the borehole should be filled by fine-aggregated
concrete and reinforced with a metal frame of a required cut. So,
the bored piles are installed and concreted directly on a site. The
diameter varies up to 1500mm and depth - up to 10m or 30 m and
more. To increase bearing capacity the piles should be installed
with a widening at the bottom of the borehole (a foot of pile).
Mostly such types of bored piles are used in situations when there
are heavy loads to a foundation and the few compressible soils are
deep-seated.
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33. Bored Pile installation
The installation of bored piles is free of dynamic effects to soils and
foundations of existing buildings. This main advantage of bored
piles is more appreciable during a construction within the urban
zone. Moreover this type of foundations allows installing of a pile in
any soil; even there are construction waste, remains from the
previous structures and boulder and cobble deposits.
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34. Bored Pile installation
Quality control is very important during installation of bored piles. All
rigs are equipped with a special computer system to control a pile
concreting process. The monitoring piles’ parameters are depth,
pressure of concrete mix, concrete volume and shape of piles.
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39. THANK YOU
Made by :
Ahmed Mohamed Zanaty 9103710
2. Ahmed Abdullah Negm 9104441
3. Mohamed Ahmed El Saeid 9103644
4. Abdelrahman Mohamed 9104286
5. Ahmed Youssef 9100499
• Departure:
Construction & Building
• Course
Foundation
• Under supervision of:
Prof. Adel Belal
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