[FRANKI] Displacement Piles

7/30/2019 [FRANKI] Displacement Piles

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Sydney (Head Ofce)

Level 1, 4 Burbank Place

Baulkham Hills NSW 2153 Australia

T: +61 2 8866 1100 F: +61 2 8866 1101 Email: [email protected]

DISPLACEMENT PILES

This pile type is similar to the Atlas pile with the exception that

most displacement piles are straight shafted as opposed to the

helical shafts on the Atlas piles. These piles are installed using

modern, very high torque hydraulic drilling rigs which rotate

a specialised displacement tool into the ground. The action of

the specially designed tool causes the ground to be compacted,

when the tool has reached the required depth it is withdrawn

whilst concrete is pumped out through the hollow stem.

The installation process of both types is totally vibration free but

the major advantage is that the process produces no spoil with, theexception of minor ground heave, thus obviating the need to deal with

any contaminated spoil.

ATLAS PILES

The Atlas pile is a unique screw shaped reinforced concrete

pile design to take maximum advantage of all the available soil

capacity by displacing the soil rather than replacing it.

The Atlas pile is a concrete cast in-situ and is not to be confused with

the steel screw pile which has much lower load carrying capacity. The

piles can be installed with a conventional purpose built Atlas rig or

the new generation high torque hydraulic piling piles allowing pilesup to 30m to be installed in a single pass. As these piles are genuine

displacement piles with the auger being thrust into the ground with

a minimum of 40 tonne metre torque negligible spoil is produced for

subsequent removal, very important consideration when piling in

contaminated or aggressive soils.

DISPLACEMENT PILES


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CONTINUOUS FLIGHT

AUGER (CFA) PILES

LOAD CAPACITY

CFA Piles are most suited or use in sands with load capacity

developed in both adhesion and end bearing. The designresistance may be calculated using conventional static pile

design theory with design parameters relevant to non-

displacement piles.

The pile founding depths should be predetermined before installation

from a site investigation report.

This pile type is also suited for use in rock with available equipment

able to form sockets in weak to medium strong rocks. CFA piles are not

normally viable in lower strength clays, unless a suitable end-bearinglayer is available to found in.

CONTINUOUS FLIGHT

AUGER (CFA) PILES

The CFA Pile is a non-displacement pile used where ast

vibration ree installation is required in difcult ground

conditions. The drilling process is suitable or penetrating

dense layers and is unaected by ground water or collapsing

soil conditions.

The pile is formed by rst drilling into the ground with a continuous

ight auger.

Cement-sand grout or concrete is then injected under pressure through

the augers hollow stem as it is being withdrawn.The grout or concrete pressure is maintained during the auger

withdrawal so that it assists the extraction as well as exerting a lateralpressure on the surrounding soils. On completion of this operation, a

reinforcing cage is placed into the uid column of grout or concrete.


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FRANKI PILES

FRANKI PILES

Although the Franki pile is generally installed by bottom

driving, highly special techniques such as open-ended coring,

rock socketting, and composite shaft construction are used in

particular situations to overcome unique site problems.

It can safely withstand very high compressive and tensile forces and

substantial horizontal loads.

The installation process of each Franki pile takes account of the soilconditions at each pile location. Quality control checks on the driving

and basing resistance of every pile result in optimum pile performance.

The pile is always sealed during construction. Ground water or

collapsing ground present no problems.

Noise and vibration levels are minimised as a result of Frankis uniquebottom driving technique.

Because the impact occurs at the bottom of the tube, the

Franki pile is the quietest of the driven cast-in-place systems and is

suitable where high noise levels would cause environmental problems.

Vibration levels are monitored regularly and in most ground conditionscan be kept below the strictest international standards.

These features have helped make the Franki pile the most popular cast-

in-place pile in Australia for more than 50 years.


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THE FRANKI BASE & SHAFT

The action of forming an enlarged base improves and

strengthens many soil types. Also the pile base can be enlarged

up to three times the shaft diameter resulting in a shorter more

economical pile which has superior settlement performance

when compared to a straight shaft pile.

Where high tension loads are required, the reinforcement can be

anchored into a tension base giving signicantly increased tension

resistance.

The load capacity and settlement analyses of Franki piles are calculated

using displacement pile parameters with design methods based on

many years of research and thousands of test pile results in a widerange of ground conditions. Theoretical expectations are conrmed

during construction by monitoring the dynamic resistance of the piling

tube and the energy requirements for forming the enlarged base. The

pile type can be constructed in practically all soil conditions.

FRANKI PILES, cont


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Sydney (Head Ofce)




BORED PILES

Large diameter bored piles are non displacement piles which

are commonly used where large vertical loads or bending

moments must be carried by a single unit.

Bored piles founded in rock provide an effective means of minimising

foundation settlements and a small number of high capacity bored

piles can often provide signicant savings in pile cap costs over other,

lower capacity, pile types.

Being non displacement type piles, bored piles can be installed with little

or no vibration, and with much lower noise levels than driven piles.

Franki has a large range of equipment available for the execution of

bored piles ranging from limited headroom equipment to modern allhydraulic tracked machines capable of drilling holes in soil and rock.

Soil and or rock is removed using purpose designed drill tools including

soil and rock augers, drilling buckets, core barrels, and down hole

hammer drills. Drilling to depths of up to 60 meters and to diameters

from 300mm to in excess of 2 metres is possible in soil and rock.

Various methods of support for the sides of bored piles duringconstruction are available. These can be selected to suit the type of

formation being drilled, the ground water regime encountered, and site

environmental constraints.

BORED PILES


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BORED PILES, cont

Shaft support methods available include:

* Vibrated temporary casing.

* Drilled temporary casing.

* Oscillated temporary casing.

* Permanent liners.

* Drilling under water.

* Drilling under bentonite.

* Drilling under polymer uids.

The load capacity of bored piles is a function of the geotechnicalcapacity of the pile, the installation technique chosen, and the

structural capacity of the pile shaft. The capacity of piles socketed into

good quality rock is often limited by settlement considerations. Bored

piles are also particularly suited to providing resistance to high lateral

loads such as those induced by wind loading and earth quake loading.

In these circumstances the larger diameters available, combined withheavy steel reinforcement cages if required, provide the required

structural strength.

In very hard rock, bored piles can be constructed using down the hole

hammer drills or roller cutter core barrels. These techniques allow

the drilling of hard and abrasive rocks which would otherwise be verydifcult to penetrate economically with conventional

drilling equipment.

In some circumstances, belling techniques may prove economical to

take advantage of high end-bearing resistance. Typical bell diameters

of up to 2 times the shaft diameter can be constructed by

mechanical means.

The actual load capacity of bored piles can be veried by static

geotechnical calculations, by logging of shafts during drilling, by static

or dynamic load testing, or by Statnamic load testing which provides

an economical means of testing to high load levels.

BORED PILES, cont


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Sydney (Head Ofce)




PILES IN RESTRICTED AREAS

Franki has the equipment and expertise to construct piles

in restricted areas with a minimum of noise and vibration

including areas with head room as low as 2.4 metres.

Where access is a problem, Franki offer:

* Bored piles and groutcrete piles up to 500mm diameter.

* Forum piles, the original enlarged base piles for maximum load inconned areas.

* Tube piles for areas where ground water is a problem.

The product used depends on the load requirements and conditions.The equipment used is based on either the Franki mini rig, or the

traditional tripod rig.

Applications include:

* Underpinning.

* Renovations to existing structures such as shops, railwaystations, etc.

* Bridge extensions in awkward locations.

The traditional Forum pile system can be disassembled to allow access

to normally inaccessible areas.

The base of the Bawang pile is expanded to increase pile load capacityafter the pile has reached the required depth.

PILES IN RESTRICTED AREAS


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DRIVEN PRECAST PILES

The Franki precast pile is a high strength high capacity precast

concrete pile which incorporates mechanical and compression

joints, allowing piles to be spliced quickly and then driven to

any required depth.

Precast piles offer the geotechnical efciency of a driven pile with the

economies of a mass produced product. A rigorous quality assurance

program throughout the casting, driving and testing process ensures aconsistently reliable product with high strength and durability. Precast

piles are most suited to ground conditions where soft upper strata

overlie a hard bearing layer and in areas with clay or silt deposits.

Franki maintains its own casting facilities which enables it to cater for

varying site conditions with a range of stock pile lengths & sizes.

Franki maintains in house casting capacity sufcient to customise pile

lengths for individual sites and to cater for site variability without the

need for long casting periods prior to job commencement.

DRIVEN PRECAST PILES

THE PILE JOINT

Franki has two main types of pile joint:

1. The compression sleeve - an economical join used when there are no

tension loads or high movements on the pile.

2. A mechanical joint - Which is cast into the piles and consists of a series

of pins and recesses that are mated during the pitching process andare then held in place by the inserton of high strength steel wedges.

The mechanical joint is designed and proof tested to ensure that where

necessary the compression, tension and bending stresses are similar

to that of the pile section.

LOAD CAPACITY

Franki precast piles are manufactured from high strength concrete usingstate of the art technology. Structural load capacities are based on an

independent testing and research program.

Piles are driven using the most sophisticated piling machines operating

in Australia. These are equipped with efcient hydraulic hammers for

faster installation and lower pile stresses during driving.

The geotechnical strength and serviceability are determined usinganalytical methods applicable to displacement piles and parameters

based largely on intensive static and dynamic load test results.


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Sydney (Head Ofce)




Pictured above: Piled foundations for silos at the casting basin, Tempe

NSW, used in the construction of the underground rail link to Sydneys

Mascot airport

Frankipile also supply and drive other types and preormed

piles such as:

* pre stressed octagonal piles

* steel bearing piles

* steel sheet piles

* steel tube piles

DRIVEN PRE-FORMED

TIMBER PILES

Timber was the frst material to be used in piling work and was

the only material used or this purpose or many centuries.

Timber is popular in Marine applications as it is a tough resilient

material which can absorb considerable shock without serious damageby such incidents as collision. They are also more easily repaired than

steel or concrete piles.

Timber is renowned for its inertness and as such has the natural ability

to perform its task long term in hostile chemical soil conditions. The

availability of modern timber preservation technology has increased

this popularity of timber piles in chemically aggressive soils. It isideally suited to applications where an economical pile is required to

carry small axial loads.

Frankis eet of Driving rigs are well suited for the fast and economical

installation of timber piles both on land and also in marine applications.

DRIVEN PILES


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Sydney (Head Ofce)




SECANT PILE WALLS

RETAINING WALLS, cont

SHEET PILE WALLS


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RETAINING WALLS, cont

PREFABRICATED WALLS


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Dynamic LoaD TesTing

D ld tt (DLT) hh tr tt thd fr

pl prfr. ovr th lt 15 r, t h b

th prdt f pl ld tt wrldwd. DLT

vlv pt th hd f pl wth pl hr

r drp wht d ur th rultt tr d

lrt. Th urt r ud t qutf th

pl d l bhvur rp t th ppld d

fr. s prtt pblt f th DLT thd r

urd fllw:

* Relatively quick and economical means of quality control for pileconstruction.

* On-site monitoring of piling hammer performance.

* Assessment of driving problems and/or pile damage.

* Provides immediate estimate of mobilised pile resistances during

the blow.

* Can be applied to all types of pile foundation.

While originally developed for driven piles, the DLT method has beensuccessfully transferred to the testing of cast-in-place piles. DLT, when

applied to pre-formed driven piles, is a powerful diagnostic tool to

control and identify problems in the pile driving process.

DLT is carried out using either the Foundation Pile Diagnostic System

(FPDS), manufactured by the TNO Building and Construction Research

Organisation in the Netherlands or the PAK System, manufactured byPile Dynamics, Inc. of the USA. Both systems comprise a portable eld

computer with signal processing electronics, a signal conditioning

system, two strain gauge/acceleration transducers, together withsoftware for monitoring and reporting.

DYNAMIC LOAD TESTING


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Sydney (Head Ofce)




DYNAMIC LOAD TESTING, cont

The analysis is carried out using the signal matching program

CAPWAP. Pile and soil data are modelled and a response is ca

lculated based on one dimensional wave equation theory. The signal

matching process utilises an iterative method in which the results of

each analysis are compared to the actual measured pile behaviour.Appropriate dynamic soil parameters are rened until a satisfactory

match is achieved. The mobilised static shaft and toe resistance of the

pile can hence be derived. The signal matching program also provides

a prediction of the static load displacement performance of the pile on

the basis of the rened pile and soil model.

HoW Does iT WoRK?

Dynamic load testing is carried out with two identical bolt-on strain andacceleration transducers attached to a section of pile. The pile is then

struck with a driving hammer or a separate drop weight. A hammermass of about 1 to 2% of the test load is generally sufcient. The

generated compressive stress wave travels down the piles and reects

from the pile toe upward. The stress waves, which are picked up by the

transducers, are processed and automatically stored in the computer

for further analysis and reporting.


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Sydney (Head Ofce)




Static Load teSting

th s l s (SLt) vlvs h r msurm

pl h splm h rsps physlly ppl

s l. i s h ms uml rm pl l s

s sr s h bh-mrk pl prrm. ts

hs b prrm h l r 100kn 12,000 kn. th

SLt my b rr u r h llw l furs:

* Compression

* Lateral

* Tension (i.e. uplift)

For the SLT the load is most commonly applied via a jack actingagainst a reaction beam, which is restrained by an anchorage system

or by jacking up against a reaction mass (kentledgeor dead weight).

The anchorage system may be in the form of cable anchors or reaction

piles installed into the ground to provide tension resistance. The

nominated test load is usually applied in a series of increments in

accordance with the appropriate Code, or with a pre-determined loadtesting specication for a project. Each load increment is sustained for

a specied time period, or until the rate of pile movement is less than a

nominated value.

Static load testing methods are applicable to all pile types, on land

or over water, and may be carried out on either production piles or

sacricial trial piles. Trial piles are specically constructed for the

purpose of carrying out load tests and therefore, are commonly loaded

to failure. Testing of production piles however, is limited to prove that apile will perform satisfactorily at the serviceability or design load, plus

an overload to demonstrate that the pile has some (nominated) reserve

capacity.

tHe teSt PRocedURe

Loading is applied to the test pile using a calibrated hydraulic jack, and

where required a calibrated load cell measures the load.

During the SLT, direct measurements of pile displacement under the

applied loading are taken by reading deectometers (dial gauges

reading to 0.01mm) that are positioned on glass reference plates

cemented to the pile head. The deectometers are supported by

reference beams that are founded a specied distance away from boththe test pile and any reaction points.

Although SLT is generally held as the most reliable form of load

testing a pile or pile group, it is important that interaction effects areminimised. These may result from interaction between the test pile and

the anchorage systems, or between the measuring system and reaction

points. For this reason, careful attention is given to performing the test

in accordance with proper procedures.

teSt ReSULtS

Test results are presented inconventional graphical format showing the

applied load versus pile head displacement.

STATIC LOAD TESTING


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Sydney (Head Ofce)




STATIC LOAD TESTING, cont

The analysis is carried out using the signal matching program

CAPWAP. Pile and soil data are modelled and a response is ca

lculated based on one dimensional wave equation theory. The signal

matching process utilises an iterative method in which the results ofeach analysis are compared to the actual measured pile behaviour.

Appropriate dynamic soil parameters are rened until a satisfactory

match is achieved. The mobilised static shaft and toe resistance of the

pile can hence be derived. The signal matching program also provides

a prediction of the static load displacement performance of the pile on

the basis of the rened pile and soil model.

HoW doeS it WoRK?

Dynamic load testing is carried out with two identical bolt-on strain andacceleration transducers attached to a section of pile. The pile is then

struck with a driving hammer or a separate drop weight. A hammermass of about 1 to 2% of the test load is generally sufcient. The

generated compressive stress wave travels down the piles and reects

from the pile toe upward. The stress waves, which are picked up by the

transducers, are processed and automatically stored in the computer

for further analysis and reporting.


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Sydney (Head Ofce)




Sonic integrity teSting

th s s (Sit) s a -dsuv s f

qukl ad mall hk h u f

a salld pl fuda. th mhd s fd as a lw-

sa s ad s ul usd f qual l pupss

pl pjs.

SIT can be applied to cast-in-situ piles and pre-formed driven piles

(concrete, steel, timber). The test will detect pile defects like cracks, voidsand soil inclusions, changes in the pile diameter (e.g. necking), and

major variations in the consistency of the pile material. The method does

not provide any information on the load bearing capacity of the pile.

The equipment used for SIT is robust and portable and comprisesa light-weight eld computer, transducer, connecting cables and a

plastic mallet. Thus, any accessible pile can be tested by a single

operator. An experienced operator can test up to 100 piles per day in

ideal conditions. In most cases, the experienced operator can provide

immediate on-site interpretation of the test result.

PHenoMenA DetectABLe

* Reections from the toe, (in most cases).

* Reections from signicant inclusions (5-10% or more of the pile

diameter).

* Reections from horizontal cracks.

* Reections from joints, (as for precast concrete piles).

* Reections from increases and decreases in cross-section.

* Reections from changes in soil layers.

* Reections from signicant changes in material properties (e.g.

variation in concrete consistency).

PHenoMenA not DetectABLe

* Gradual increases or decreases in cross-section.

* Curved forms.

* Small inclusions of foreign materials.

* Local loss of cover.

* Debris at the toe of the pile.

* Cracks parallel to the pile axis.

SONIC INTEGRITY TESTING


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L l 1 4 B b k Pl

SONIC INTEGRITY TESTING, cont

Sonic integrity teSting

HoW DoeS it WorK?

1. The pile head is struck with a hand-held hammer, which sends a

low strain stress wave down the pile shaft.

2. The induced stress wave is reected off the pile toe and any

discontinuities in the pile.

3. The reections cause movements of the pile head, which are

registered by a hand-held accelerometer sensor that is pressed

against the top of the pile.

4. The recorded signal is converted into a velocity-time trace and

presented on-screen as velocity versus pile depth.

5. Once satisfactory signals have been obtained, they are stored in

the internal memory of the eld computer.

6. The stored signals are downloaded onto a PC for signal

enhancement and reporting at a later stage.

The shape of the recorded sonic signals (reectograms) provides aqualitative indication of the pile integrity. However, interpretation of

SIT signals must give due regard to the soil prole in which the pile

is founded and the method of pile construction. Shaft friction plays a

major role in damping the signal and reections of stress waves also

occur at the boundary of soil layers. For this reason it is essential that

the operator is provided with available soil prole details, together withthe pile construction records.

[FRANKI] Displacement Piles

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