Piling Workshop Rev.a Singapore

Pile Driveability Workshop

Saipem Singapore Ltd.

01 September 2007 Singapore, Presented by: C. Parisi (Saipem S.p.A.)

5People, Ideas, Energy

EniEniEniEniTABLE OF CONTENT

Foundation Piles Overview General Definitions Driveability Analysis Overview Soil Resistance to Driving (SRD) Pile Stick-up Analysis GRLWEAP Software Overview Pile Installation Overview Hammer Overview Hammers Refusal Criteria Pile Handling Piling Engineering Pile Complex Project Case : TTPP Project (PTT Thailand) Pile Stick-up Analysis Hand Calculation (Example) References

Foundation

5

Structures and components that carrying out

the full weight of an offshore structure

against all external actions and anchor the

platform to the sea floor

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Topside Facility(Upper structure/Deck)

Piles / Foundation

Jacket (Sub structure)

Sea Bed

Sea Level


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TYPES OF FOUNDATIONSTYPES OF FOUNDATIONSPeople, Ideas, Energy

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Main PileFoundation pile (multiple sections) which are driven into the seabed through the jacket legs of the platform

TYPES OF FOUNDATIONSTYPES OF FOUNDATIONS

Skirt Pile Foundation pile (one section) that are installed inside the sleeves welded around the jacket legs


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Suction PileLarge diameter of pile with a relatively short penetration (one or two times pile diameter) mostly used to mooring anchors in a deep sea. It offers several advantages e.g. installation that relies on pumps rather than underwater hammer. Installation involves penetration by deadweight and the reduction of pressure under the caisson cap creating a downward differential pressure. It is used where the soil at the pile base has desirable permeability.


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Caisson Cap


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Pin PileA large diameter of foundation pile (7296) that driven to seabed through a template guide


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Pin Pile Installation Sequence

1 Driving pin piles through the template guide

2 After driven (template guide has been removed)

3 Placing the jacket to the pin piles

4 Driving skirt piles through the jacket sleeves

5 After driven


Anchor PileFoundation pile (one section) for FPSO, CALM buoy or PLEM with small design penetration (e.g. 1425m)


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HydroHammer

+

Follower

AnchorPile +

Padeye

PLEM

HydroHammer

+

Follower

PLEM Pile

Conductor Pile (not a foundation pile)The scope of conductor pile is only to be a template-guide to the drill string that will reach the well of the gas or oil field. It has typical outside diameter (20 or 30) with an uniform wall thickness (1). Installed in vertical position.


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SOME DEFINITIONSSOME DEFINITIONS

HammerA machine that able to drive the pile into the soil up to desired penetration. Depend on its use, hammer consist of 3 types: Main Hammer / Spread Hammer

Hammer that able to drive up to the target penetration in anycondition (continuous and restart).

Back-up HammerHammer that able to replace main hammer with the same energy or more powerful.

Contingency HammerPowerful hammer to be used in case of the following contingencycircumstances: High soil resistance encountered Unexpected main hammer refusal In case main/backup hammer damage


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continuation......

Underwater BallastAn additional device needed for hydraulic hammer tocompensate the weight loss when it is used for under water driving.

Striking EnergyEnergy produced by hammers machinery.

Hammer EfficiencyRatio between the striking energy produced by hammer(considering internal mechanical losses) and hammernominal striking energy.

RamPart of hammer that moves up and down to generate the striking energy.

E = Mass of Ram x Stroke HeightE = Nominal of striking energy (kNm)


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Ram

Anvil


continuation......

Helmet (the cap)All components located underneath the hammers ram and above the pile.

Hammers Cushion BlockA relatively lightweight and flexible material (e.g.: bongossi wood, alumunium micarta, etc.). Its function is primarily to protect pile againsthigh stresses.

Anvil (the striker plate)Part of hammer that contacts with the top of pile.

Hammer Sleeve / Hammer CageThe bottom part of hammer that will fit on the top of pile to align hammerand pile.

Blow CountNumber of hammer blows per linier unit of pile penetration (bl/25cm or bl/m).


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continuation......

Pile RefusalThe point where the pile driving with a proposed hammer has to be stopped and other methods instituted (e.g. drilling system or using a powerful hammer).

Cantilever SectionLast restrain that holds the pile after being placed on the jacket leg (e.g. jacket top horizontal frame, jacket sleeve for skirt pile).

Resulting Free Standing LengthActual length of a pile calculated from last restrain (i.e. cantilever section).

Allowable Free Standing LengthMaximum allowed length of pile that can withstand static loads (axial and bending) without overstress.


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continuation......

Static StressStresses on the pile (bending and axial compressive stress) due to its weightand hammer weight.

Dynamic StressCompressive stress on pile sections that occur during driving due to hammerimpact.


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SCOPE OF DRIVEABILITY ANALYSIS

Driveability analysis is performed to verify if the selected hammer is able to drive the pile up to the target penetration in any conditions (continuous or restart mode).Pile driveability is performed through steps:

1. Estimation of soil resistance to driving (SRD) in accordance with International Engineering Standards and Guidelines (e. g. API RP 2A-WSD, OTC 3969 Semple article, OTC 4205 Stevens article, OTC 6237 Puech article and other technicalarticles).

2. Static and dynamic pile stick-up analysis.3. Pile driveability evaluation by using GRLWEAP software.


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SRD Estimation

Stick-up Analysis

Wave Equation Analysis (GRLWEAPTM)

Blow Count Estimation

Blow Count >Pile Refusal

Blow Count < Pile Refusal

Dynamic Stress Evaluation

Comp. Stress < 8090% SMYS

Dyn. + Static Stress > SMYS

Dyn. + Static Stress SMYS

FINISH

START

Higher StrikingEnergy

Lower StrikingEnergy

Comp. Stress > 8090% SMYS

-Soil Investigation Report-Pile Configuration

More powerful Hammer

Static Stress at Cantilever or Critical Section

Unity Check 1.0 Unity Check > 1.0Pile Make-up Modification

Lighter Hammer

Remedial Action


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SOIL RESISTANCE TO DRIVING (SRD)SOIL RESISTANCE TO DRIVING (SRD)

Def : Resistance of soil encountered by pile during driving.

Generally, there are 4 SRD conditions to be considered :Lower Bound Plugged and Unplugged (Core), Upper Bound Plugged and Unplugged (Core)

Lower Bound and Upper BoundEstimation of soil resistance that might be occur during driving, rangefrom minimum to maximum value.

Plugged Pile ConditionA condition where the soil inside the pile moves downward together withthe pile during driving. Soil resistance due to external friction and end bearing.

Unplugged Pile ConditionA condition where the soil inside the pile remains stationary duringdriving. Soil resistance due to internal and external pile friction, annulusend bearing.


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Ultimate Pile CapacityCapacity of the pile to withstand axial load in static condition. Usually, foundation pile gain its ultimate capacity at certain period of time after driving ( Qult = Qf + Qp ). Qf = skin friction resistanceQp = total end bearing

RestartResumption of driving after interrupted for welding add-ons, hammerchange, etc. For long delay, ultimate capacity might be encountered(depends on type of soil , i.e. clay).

Pile Self Weight Penetration (SWP)Pile penetration estimation based on equilibrium between the initialassembled pile weight (with or without hammer) and the soil resistance.


EniEniEniEni SOIL RESISTANCE TO DRIVING (SRD)SOIL RESISTANCE TO DRIVING (SRD)



Soil TypeSoil Type DescriptionDescription Design Design ParametersParameters CategoriesCategories

CLAY CLAY (Cohesive Soil)(Cohesive Soil)

SiltySilty CLAYSCLAYS(Cohesive Soil)(Cohesive Soil)

Cu Cu ((UndrainedUndrained

Shear Shear Strength),Strength),

(Submerged (Submerged unit weight)unit weight)

SANDSAND((CohesionlessCohesionlessSoil / Granular)Soil / Granular)

SiltySilty SANDSSANDS((CohesionlessCohesionless

Soil)Soil)

Composed of individual soil Composed of individual soil particles that slide when it is particles that slide when it is loaded. Can only be held loaded. Can only be held together by confining together by confining pressure. pressure.

(internal (internal

Friction Angle), Friction Angle),

(Submerged (Submerged unit weight)unit weight)

Very LooseVery LooseLooseLooseMedium DenseMedium DenseDenseDenseVery DenseVery Dense

ROCKROCKComposed of material that Composed of material that bond each others, e.g. bond each others, e.g. sandstone, limestone, sandstone, limestone, conglomerate, etc. conglomerate, etc.

UCSUCS(Unconfined (Unconfined Compressive Compressive

Strength)Strength)

Very WeakVery WeakWeakWeakModerately StrongModerately StrongStrongStrongVery StrongVery Strong

Composed of fines soil Composed of fines soil particles (



Calcareous Silica SILT

Calcareous Silica SAND

CLAY HARD CLAY

ROCKSAND

PILE STICKPILE STICK--UP OVERVIEWUP OVERVIEW

EachEach foundationfoundation or conductor pile on or conductor pile on whichwhich a a hammerhammer willwillbebe placedplaced shallshall bebe checkedchecked forfor loadsloads causedcaused byby itselfitself weightweightand and installationinstallation equipmentequipment (e.g. (e.g. stabbingstabbing guide, guide, internalinternalclampclamp, , etcetc.)..).

TheseThese loadsloads maymay bebe limitinglimiting factorsfactors in in establishingestablishing the the maximummaximum lengthlength of the of the addadd--onsons or the or the suitablesuitable spreadspreadhammerhammer forfor the the skirtskirt pilespiles in in orderorder notnot toto damagedamage the pile.the pile.

ToTo avoidavoid failurefailure of the pile of the pile installationinstallation due due toto the the aboveabovementionedmentioned loadsloads, the , the pilespiles and and hammerhammer equipmentequipment shouldshouldbebe designeddesigned toto satisfysatisfy bothboth strengthstrength and and stabilitystability criteriacriteria..


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PILE STICK-UP ANALYSIS

Scope of the stick-up analysis are :1. Evaluate the allowable free-standing length (Lfs) for a given pile make-up / hammer configuration or ;

2. Verify the Rfs (Resulting free-standing length) is lesser than Lfs for a given pile section in order not to damage the pile sections during placement of the hammer spread and during the pile driving up to the target penetration.


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Calculation of pile stick-up is performed according to API RP 2A WSD, 2002 edition (American Petroleum Institute Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms -Working Stress Design).

The following conditions are verified : Static pile stick-up - Each column pile section must resist axial loads

and static bending that are generated during initial hammer placement.fs = fa+fb

Dynamic pile stick-up - Each free-standing pile section must resistdynamic stresses that occur during driving.

a) f dyn 8090 of SMYS b) fs +f dyn 100% SMYS


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Where : fs = Static Stress, MPafa = Actual Compressive Stress, MPa

= Axial Load / Apile on cantilever sectionSMYS = Specified Minimum Yield Strength of the pile, MPa

fb = Actual Bending Stress, MPa= Bending Moment / Section Modulus

F dyn = Dynamic Stresses, MPa

where:mh = weight of the hammer, cap, and

leads (kN); mL = weight of the pile (kN);Rfs = free standing length of the pile (m); C.o.G.= distance of mh barycentre from pile

head (m); = inclination of the pile/ true batter

(degrees).


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The bending moment and axial load acting in the critical section have been evaluated as:M = mh x (Rfs + C.o.G.) x sin (alpha) + mL(Rfs / 2) x sin ()N = (mh + mL) x cos ()

API Minimum Bending Moment API Minimum Bending Moment (Section 6.10.4) :(Section 6.10.4) :0.02 x hammer weight x resulting free standing length


Cantilever section


a) Cantilever section at top jacket frame (Main pile, Conductor pile)

b) Cantilever section at pile sleeve(Skirt pile)

c) Le = K x RfsK = 2.1 (required by API-RP2A WSD)Rfs = Free standing length from

cantilever section.


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60tD

,

c

cc

c CrKlfor

CrKl

CrKl

FyCrKl

Fa Fafa

0.1

'1

.

+

FbFefafbCm

Fafa

0.16.0

+Fbfb

Fyfa

( )22

/2312'

rklEFe =

15.0Fafa

0.1+Fbfb

Fafa

0.1Fafa1. 2. For

a.

b.

3. For

Cm = Minimum reduction factor (Sec.6.10.4) = 1.0K = Effective length factor (Sec.6.10.4) = 2.1fa = Actual compressive stressfb = Actual bending stress


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Combined Stress (API RP2A-WSD 2002)

Where :


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There is SMYS reduction related with pile wall thickness (steel plate).Ex : EN 10025

1

Self Weight Penetration

Rfs

For conductor pile, 1 degree inclination (include tolerance) should be considered. For main pile, pile true batter should be applied.

Free standing length for lead section should considering the pile self weight penetration


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Under Water Ballast

For skirt pile, submerged weight of the pile should be considered since some part of the pile are under water (buoyancy effect).

For hydraulic hammer, hammer weight should consider hammer configuration (with or without under water ballast).


EniEniEniEni PILE FAILURE MODE (BUCKLING)PILE FAILURE MODE (BUCKLING)

GRLWEAP : Globe Rausche Likins WaveEquation Analysis of Pile Driving

Corporate software used for pile driveabilityanalysis.

Pile driving program which simulates motionand forces in a foundation pile when drivenby an impact hammer or a vibratory hammer. The program computes the following:

1. The blow count of a pile under one or more assumed ultimate resistancevalues and other dynamic soilresistance parameters, given a hammerand driving system (helmet, cushion, etc.)

2. The axial stresses in a pile3. The energy transferred by the hammer

to the pile for each capacity analyzed Mathematical model of the soil, hammer and

pile. Soil is modeled by a series of springs and

dashpots.

Schematic Model

Soil -Pile

HammerHammer Cushion

Pile Cushion Pile

Spring

Hammer Frame

GRLWEAP OVERVIEWPeople, Ideas, EnergyEniEniEniEni

Hammer and pile is modeled by a series lumped mass connected by springs.

MAIN INPUT DATA FOR GRLWEAP TMPeople, Ideas, EnergyEniEniEniEni

Main Screen

Pile InformationPeople, Ideas, Energy

EniEniEniEni MAIN INPUT DATA FOR GRLWEAP TM

Soil DataPeople, Ideas, Energy

EniEniEniEni MAIN INPUT DATA FOR GRLWEAP TM

MAIN INPUT DATA FOR GRLWEAP MAIN INPUT DATA FOR GRLWEAP TMTM

Hammer Data (hammer type, striking energy, efficiency, helmet weight)

Hammer Cushion Data (area, elastic modulus, thickness, coefficient of restitution). Hammer cushion e.g. Bongossi, Conbest, Micarta, Alluminium, Monocast, Steel wire.

Pile Information (pile section length, outside diameter, wallthickness, yield strength, restart and target penetration)

Soil Data (quake and damping parameters, unit shaftresistance, toe resistance, ultimate capacity)


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MAIN PRACTICAL OUTPUT DATAMAIN PRACTICAL OUTPUT DATA

Blow count vs penetration depth Dynamic stress (i.e. max. compressive stress) along the pile sections

during driving ENTHRU energy (transferred energy by hammer to the pile for each

ultimate soil resistance analyzed). Global efficiency (ENTHRU energy divided by hammer nominal

striking energy)

Based on these results, the following can be indirectly evaluated: Driving pile in lower bound (low soil resistance) Driving pile in upper bound (high soil resistance) Driving pile in full set up (ultimate static capacity) or restart


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MAIN PRACTICAL OUTPUT DATAPeople, Ideas, Energy

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DRIVING RECORD

During pile driving, it is very important to record the following parameters :

Number of blow count per meter or 25 cm.

Hammer striking energy Pile self weight penetration

with or without hammer Any additional information

during pile driving process (e.g. pile refusal, hammer stops, etc)

Manual Driving Record


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Hydraulic Hammer (Menck) Driving Record

DRIVING RECORD

BACK ANALYSIS

Comparison between the estimated number of blow count obtained from driveability analysis with the actual blow count occurs in field.

Back analysis is useful for better estimation of soil resistance when driving the future pile in the nearby area.

Blow Count vs. Penetration

0

10

20

30

40

50

60

0 50 100 150 200 250 300Blow, bl/m

P

e

n

e

t

r

a

t

i

o

n

,

m

In Field IKA C1

In Field IKA C2

In Field IKA C3

In Field IKA C4

Estimated_Lower Plug

Estimated_LowerUnpluggedEstimated_Upper Plug

Estimated_UpperUnplugged


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GENERAL CORRELATION GENERAL CORRELATION STICKSTICK--UP & HAMMER ENERGYUP & HAMMER ENERGY


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Longer Pile StickLonger Pile Stick--up up Length + Heavier Length + Heavier HammerHammer

Less residual dynamic stressLess residual dynamic stress

STICKSTICK--UPUPShorter Pile StickShorter Pile Stick--up up Length + Lighter Length + Lighter HammerHammer

More residual dynamic stressMore residual dynamic stress

HIGHER ENERGYHIGHER ENERGYLow number of blow count ;Low number of blow count ;High dynamic stresses ;High dynamic stresses ;Hammer striking energy might be limitedHammer striking energy might be limitedHAMMER HAMMER

ENERGYENERGYLOWER ENERGYLOWER ENERGY

High number of blow count ;High number of blow count ;Low dynamic stresses ;Low dynamic stresses ;Pile refusal might be encounteredPile refusal might be encountered

PILE INSTALLATION

General description of a Foundation Pile installation:1. Moving piles from cargo barge to installation vessel.2. Upending Lead section by means ILT (Internal Lifting Tool),

crawler crane or upending clamp.3. Stabbing Lead section inside the jacket leg.4. Install bear cage on top lead section.5. Lifting and stabbing 1st add-on and weld.6. Welding is done either in manual mode (SMAW) or semi-

automatic mode (FCAW) or a mix of both system. The weld integrity is checked by Ultrasonic Testing (UT).


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PILE INSTALLATIONcontinuation..

7. Remove the bear cage from the piles .8. Install the hammer on pile top.9. Drive pile up to the foreseen penetration.10. Perform cut-off of damaged part due to hammers impact.11. The same installation procedure will be repeated for each add-on

up to reach the design penetration or refusal.12. Jacket leveling13. Upon completion of the pile driving and leveling, the piles are

welded to the jacket on top of legs (shims or collars).


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JACKETS DISASTER VIDEO


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PILE FREE RUNNING

Pile suddenly starts to fall rapidly after receiving hammer impact.

Several possible reasons for this occurrence :- The presence of weak soil layer below hard soil layer, e.g. clay layer

below rock. High hammers striking energy is required to break through rock layer , but the energy is excessive for driving in clay.

- Gas deposit encountered.- Etc.

A conical reduction or a follower can be used when:

The outside diameter of the pile is not suitable for the hammers anvil/sleeve

It is necessary to drive the pile above water (diesel or steam hammer)

There is interference between hammer sleeve and the jacket leg sleeves top

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PAD EYE VS HAMMER SLEEVE CLASH

If pad eye is presence on top of pile, a clash check should be conducted between hammer sleeve and the pad eye.

Clashes


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HAMMER SLEEVE VS TOP OF JACKET LEG CLEARANCE

Remaining length of the pile from top of jacket leg (clearance +hammer sleeve) should be appropriate with bear cage height (height of bear cage welding area).

Clearance


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RemainingLength

RemainingLength

BEAR CAGE (EXTERNAL PILE CLAMP)BEAR CAGE (EXTERNAL PILE CLAMP)

Bear cage holds the two section of the pile (e.g. lead section plus 1st add-on) during the offshore welding operations.


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INTERFERENCE OF PILE TOPINTERFERENCE OF PILE TOP

IfIf the the inclinationinclination of the of the jacketjacket legslegs isis tootoo high, high, therethere isis possibilitypossibility of of interferenceinterference of pile top. of pile top. ThereforeTherefore, the , the sequencesequence of pile of pile installationinstallationshouldshould bebe concernedconcerned..


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EniEniEniEniINSTALLATION CHECK LISTINSTALLATION CHECK LIST

Hammers anvil / sleeve vs. piles outside diameter Pile stick-up vs. spread hammer Hammers sleeve height vs. jacket leg / template top sleeve clearance Hammers sleeve overall outside diameter vs. jacket leg clearance Bear cage overall O.D. vs. conductor piles O.D. interference Hammers sleeve overall O.D. vs. conductor piles O.D. clearance Conductor pile O.D. vs. conductor piles O.D. clearance Bear cage weld window elevation vs. spread hammer sleeve heights Minimum self piles penetration vs. spread hammer Piles elevation vs. final piles cut-off length Foundation piles height vs. after intermediate cut-off I.D. hammer sleeve vs. O.D. skirt pile with weld beads (total gap min. 1)

TYPES OF HAMMERSTYPES OF HAMMERS

Depending on the source of energy : Diesel hammers Steam hammers Hydraulic hammersThese hammers are categorized as impact hammers.

Other type of hammer (non-impact hammer) are vibration hammers.


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Hydraulic Hammer Steam Hammer

Anvil

Cushion Block

Pile Sleeve

Ram

Piston Rod

Steam Inlet

Shock Absorber

Suppressor

Clamp Gear Case

Ram

Fuel Injection Device

Anvil

Cushion

Diesel Hammer


Vibratory Hammer

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MAIN DIESEL HAMMERS IN SAIPEM ASSETSMAIN DIESEL HAMMERS IN SAIPEM ASSETS

LOW RANGE : D30 (102 kN-m) D46 (165 kN-m) D55 (170kN-m) MEDIUM RANGE : D62 (223 kN-m) - D80 (288 kN-m) HIGH RANGE : D100 (360 kN-m) - D200 (666 kN-m)

HAMMER EFFICIENCY = Range from 60% to 70%

EASY TO USE ( TALL and LIGHT) BUT LOW CAPABILITIES FOR LARGE DIAMETER PILES

CAN BE UTILIZED ONLY ABOVE WATER

MAX. BATTER = 45 (by using cylinder length extension)

THE STRIKING ENERGY CAN BE SET ONLY TO FOUR VALUEe.g. D100-13 : 60%, 77.2%, 89.7%, 100% of nominal value

PROVIDED WITH CUSHION TO AVOID DAMAGING THE ANVIL e.g.: Aluminium, Micarta, Monocast, Combest, Steel wire, etc.

HAMMER SLEEVE / ANVIL MUST BE SUITABLE WITH PILES DIAMETER


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MAIN DIESEL HAMMERS IN SAIPEM ASSETSMAIN DIESEL HAMMERS IN SAIPEM ASSETS

Diesel Hammer Settings Energy (by Delmag Manufacturer):


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Energy Energy SettingsSettings

DelmagDelmagD55D55

DelmagDelmagD62D62--1212




Setting 1Setting 1 100 %100 % 100 %100 % 100 %100 % 100 %100 % 100 %100 %

Setting 2Setting 2 ~ 83 %~ 83 % ~ 83 %~ 83 % ~ 83 %~ 83 % ~ 89.7 %~ 89.7 % ~ 89.7 %~ 89.7 %

Setting 3Setting 3 ~ 66 %~ 66 % ~ 66 %~ 66 % ~ 66 %~ 66 % ~ 73.6 %~ 73.6 % ~ 77.2 %~ 77.2 %

Setting 4Setting 4 ~ 50 %~ 50 % ~ 50 %~ 50 % ~ 68 %~ 68 % ~ 60 %~ 60 % ~ 65 %~ 65 %


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Example of Monocast MC-901 cushion block that is inserted between ram and anvil. It may last from approximately 5000 to 15000 blows (depends on soil type and hammer use)


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MAIN STEAM HAMMERS IN SAIPEM ASSETSMAIN STEAM HAMMERS IN SAIPEM ASSETS

LOW RANGE : MRBS1800 (257 kN-m) MRBS3000 (441 kN-m) MEDIUM RANGE : MRBS4600 (676 kN-m) HIGH RANGE : MRBS5000S (735 kN-m)

HAMMER EFFICIENCY = Range from 60% to 85% normally

STEAM HAMMERS REQUIRES LARGE BOILERS MORE DIFFICULT TO HANDLE (TALL and HEAVY)

CAN BE UTILIZED ONLY ABOVE WATER WITH 10 MAX. BATTER

PROVIDED WITH CUSHION TO AVOID DAMAGING THE ANVILBongossi wood (hard wood)



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Example of Bongossi Wood cushion that is inserted inside the anvil. It may last from approximately 3000 to 5000 blows.

Example of Anvil.Due to hammers anvil shape (steps) for each suitable pile OD, there are minimum and maximum allowable pile wall thickness that can be driven.


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MAIN HYDRAULIC HAMMERS IN SAIPEM ASSETSMAIN HYDRAULIC HAMMERS IN SAIPEM ASSETS

LOW RANGE : MHU 195 (191 kN-m) MHU220 (215 kN-m) MEDIUM RANGE : MHU 600I (588 kN-m) MHU 600T (659 kN-m) HIGH RANGE : MHU 1000 (1000 kN-m) MHU 3000 (2945 kN-m)

HAMMER EFFICIENCY = Range from 85% to 95%

CAN BE UTILIZED ABOVE AND UNDER WATER WITH 14 MAX. BATTERAbove water, efficiency can be in excess of 100%

For under water driving, under water ballast is used to compensate weight loss

AVAILABLE ALSO FOR VERY LARGE WATER DEPTH

ABLE FOR AUTOMATIC RECORD DRIVING PARAMETERS(Blow count, striking energy, penetration depth, etc)



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Under Water Ballast


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VIBRATION HAMMERSVIBRATION HAMMERS

Typically for onshore applications. Efficient for shorter penetrations (piles for sub sea templates

and manifolds). Effective and quick installation. Vibratory driving occurs relatively easily in non-displacement

piles such as open-end pile or caissons. Vibratory hammer can also be adapted to work underwater

with an additional underwater kit (e.g. ICE brand).

HAMMER FREQUENCY = 4001400 VPM


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Consists of two major components : Gear case and suppressor.

The gear case contains eccentric weights, which rotate in a vertical plane to create vertical vibration.

The suppressor contains rubber elastomers, which dampen the vibration reaching the crane by 90% or more.

A hydraulic clamp, bolted to the bottom of the gear case, transmits vibration to the pile attached.


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EniEniEniEniTypes of Hammer

DescriptionHydraulic Steam Diesel Vibratory

Efficiency 85%-95% 60%-85% 60%-70% Up to 100%

Both

-

0100%

-(Vibration

per minute)

Above/Under Water Driving

Both(equipped with under

water ballast for driving

below water)

Above water only

Above water only

Hammer Cushion - Bongossi

Allumunium, Micarta,

Monocast, Combest, Steel Wire,

etc.Energy Setting 0100% 0100%

4 settings only

Blow Count Record Automatic Manual Manual

CRITERIA FOR PILE REFUSALCRITERIA FOR PILE REFUSAL

From API RP 2A-WSD 2000 Section 12.5.6 (to be used only if the event that no other provisions are included in the installation contract):Pile driving refusal with a properly operating hammer is defined as the point where pile driving resistance exceeds either 300 blows per foot (0.3 m) for five consecutive feet (1.5 m) or 800 blows per foot (0.3 m) of penetration.If there has been a delay in pile driving operations for one hour or longer, the refusal criteria stated above shall not apply until the pile has been advanced at least one foot (0.3 m) following the resumption of pile driving. However, in no case shall the blow count exceed 800 blows for six inches (152 mm) of penetration.


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CRITERIA FOR PILE REFUSALCRITERIA FOR PILE REFUSAL From hammer manufacturer (Menck):


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CRITERIA FOR PILE REFUSALCRITERIA FOR PILE REFUSAL

From hammer manufacturer (Delmag):Delmags official policy is that driving should be terminated at a penetration rate of less than 20 mm per 10 impacts (152 blows per foot). Delmags policy is that warranty conditions are voided at penetration rates less than (i.e. blow counts greater than) 240 blows per foot.Driving with every Delmag Diesel Hammer at blow count above this is possible intermittently, but prolonged operation at these higher counts only damages the pile, hammer, and related equipments. A larger hammer should be used.


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CRITERIA FOR PILE REFUSALCRITERIA FOR PILE REFUSAL Saipem Mediterranean Services Criteria for Refusal

(Doc. CR-SMS-INST-305-E) :Hydraulic Hammer Continuous Driving

250 blows per 0.25 m of penetration over maximum distance 1.50 m in one stretch.

After Successful Restart or When Experiencing Higher Soil Resistance350 blows per 0.25 m of penetration over maximum distance 0.75 m in one stretch.

End of Driving600 blows per 0.25 m of penetration over a short distance (0.25 m).

Accidental Refusal (Only When Experiencing Hard Layers or Rocks)25 blows per 0.025 m of penetration.

Re-startBlow count shall not exceed either 240 blows per 0.15 m of penetration or 600 blows per 0.25 m of penetration.


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(Doc. CR-SMS-INST-305-E) :Steam Hammer Continuous Driving

200 blows per 0.25 m of penetration over maximum distance 1.50 m in one stretch.

After Successful Restart or When Experiencing Higher Soil Resistance250 blows per 0.25 m of penetration over maximum distance 0.75 m in one stretch.

End of Driving350 blows per 0.25 m of penetration over a short distance (0.25 m).

Accidental Refusal (Only When Experiencing Hard Layers or Rocks)25 blows per 0.025 m of penetration.

RestartBlow count shall not exceed either 240 blows per 0.15 m of penetration or 350 blows per 0.25 m per 0.25 m penetration.


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(Doc. CR-SMS-INST-305-E) :Diesel Hammer

20 blows per 0.025 m of penetration (20 mm per 10 blows) 200 blows per 0.025 m of penetration 240 blows per 0.30 m of penetration.

These criteria are applied independently from continuous driving or restart, interrupted previously for at least one hour.


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PILE HANDLINGPILE HANDLING

Upending by main cranes (S7000) and lifting clamps Upending by main vessel crane and crawler crane Upending by upending clamp Launching longitudinally (utilised only in the past) Launching transversally (utilised in the past)

TO BE VERIFIED: GLOBAL AND LOCAL PILE STRESSES


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PILE HANDLING (S3000 AND CASTORO 8)PILE HANDLING (S3000 AND CASTORO 8)

SKIRT PILES On board: 6065m (S3000) or 7075m (Castoro 8) Longer lifted length (upending clamp): 130m, 50m overhanging

MAIN PILES Longer lead section length: 7075m (due to hook height) Longer add-on section: 3840m (due to practicality) Use bear cages or turnbuckles according to main on board practice

TO BE VERIFIED: GLOBAL AND LOCAL PILE STRESSES


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INSTALLATION AIDS FOR PILE INSERTIONINSTALLATION AIDS FOR PILE INSERTION

Skirt pile lateral guide Main docking pile guide Bear cages to help main pile welding operation and access Turnbuckles to help main pile welding operation and access

TO BE VERIFED: LOCAL IMPACT STRESSES ONTO AIDS


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CONNECTION PILE TO PLATFORMCONNECTION PILE TO PLATFORM

Grouting Crown plates Pins for small manifolds and shorter piles

TO BE VERIFED: LOCAL IMPACT STRESSES ONTO AIDS


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CONNECTION PILE TO PLATFORMCONNECTION PILE TO PLATFORMPeople, Ideas, EnergyEniEniEniEni

GROUTING

CROWN SHIM

CONNECTION PILE TO PLATFORMCONNECTION PILE TO PLATFORMPeople, Ideas, EnergyEniEniEniEni

EPIC PILING ENGINEERING (SKIRT PILE)EPIC PILING ENGINEERING (SKIRT PILE)

Establish previous comparable cases Evaluation of stick up and driveability of some diameters Consideration of platform variation vs pile diameter Consideration of soil strata features vs penetration Avoid to reach very hard soil strata If unavoidable, start driving before the hard soil Reduced penetration means easier installation but also reduced

capability to carry foundation loads Increased penetration means harder driving but increase of capability

to carry foundation loads Book on time hammer spread and handling spread Establish contingency cases (drilling and jetting)

BALANCE TO BE PERFORMED FOLLOWING EXPERIENCE AND GOOD SENSE


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EPIC PILING ENGINEERING (MAIN PILE)EPIC PILING ENGINEERING (MAIN PILE)

Establish previous comparable cases Evaluation of stick up and driveability of some diameters Consideration of platform variation vs pile diameter Consideration of soil strata features vs penetration Avoid to reach very hard soil strata If unavoidable, start driving before the hard soil with final hammer Reduced penetration means easier installation but also reduced

capability to carry foundation loads Increased penetration means harder driving but increase of capability

to carry foundation loads Book on time hammer spread, handling spread Establish contingency cases (drilling and jetting)



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T&I PILING ENGINEERINGT&I PILING ENGINEERING

Pile diameter established by others Establish previous comparable cases Evaluation of stick up and driveability Consideration of soil strata features vs penetration Avoid to reach very hard soil strata If unavoidable, start driving before the hard soil Book on time hammer spread, handling spread Establish contingency cases (drilling and jetting)



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VERIFICATION TO BE PERFORMEDVERIFICATION TO BE PERFORMED

Free standing length vs reaction on bear cages Verify the vessel practical capabilities not only theoretical Establish a plan to maximise number of contemporary piles on which

installation shall occur Book relevant bear cages or turnbuckle spread (if requested) Bear cage weld window elevation vs spread hammer sleeve height In case of multiple driving verify if top of pile do not interfere (due to free

standing length vs batter) For skirt piles verify clearances between overall diameter of hammer bell

with jacket leg For main pile verify the clearances between preinstalled piles including

pile deformation due to self weight Hammer sleeve height vs top of jacket leg/template clearance If self weight penetration of initial assembled pile can reach the 1st

intermediate penetration, pile is not necessary to be driven.


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A TYPICAL PILE COMPLEX PROJECTA TYPICAL PILE COMPLEX PROJECTPTT ThailandPTT Thailand


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EniEniEniEni PROJECT OVERVIEW PROJECT OVERVIEW PROJECT :PTT RISER Platform (PRP) Third Transmission Pipeline Project (TTPP), Erawan Field, Gulf of Thailand.

CLIENT :PTT Public Company Limited

CONSULTANT :Bechtel International Inc.

CONTRACTOR :SAIPEM Asia Sdn.Bhd. / SOME Pte.Ltd.Consortium

PRP COMPLEX CONSISTS OF :PRP Jacket (8 Legged) Flare Tripod Pedestrian Tripod

WATER DEPTH :63 m depth

INSTALLATION VESSEL :Castoro 8


EniEniEniEni LOCATION MAPLOCATION MAP

PRP Complex

Platform Location

1,003,550

1,003,600

1,003,650

1,003,700

1,003,750

752,500 752,550 752,600 752,650 752,700 752,750 752,800

Easting (m)

N

o

r

t

h

i

n

g

(

m

)

Pedestrian Tripod

Flare Tripod

PRP Jacket


EniEniEniEniPRP JACKET DRAWINGPRP JACKET DRAWING

Elevation Row 1 Elevation Row A

Jacket Framing Plan


EniEniEniEni PRP JACKETPRP JACKETFOUNDATION PILES INFORMATIONFOUNDATION PILES INFORMATION

Legend :Available Spread Hammer

Proposed Hammer

Analyzed Hammer

Platform OD, WTOD, WTSMYSSMYS[MPa][MPa]

ConfigConfig..TotalTotal

LengthLength

345345414414

Org :Org :196.7m196.7m

Vertical Vertical TargetTargetPent.Pent.

SpreadSpreadHammersHammers

126m126m(127m)(127m)

D100D100--13, 13, MHU 600B,MHU 600B,MHU 800S,MHU 800S,MHU 1000, MHU 1000, MHU 1700MHU 1700

PRP JacketPRP Jacket(8 No. Piles)(8 No. Piles)

LegLeg A1A1--4 & B14 & B1--44Batter = 8.05Batter = 8.05

48,48,1.53.251.53.25

Lead Lead SectionSection

++4 Add 4 Add --

onsons

10

0

50

100

130

z (m)

20

30

40

60

70

80

90

110

120

SRD (kN)10,000 50,000

SRD Lower Bound

SRD Upper Bound

R ultimate API 2000-Fugro

R ultimate Static Capacity API 2000


EniEniEniEni PRP JACKETPRP JACKETESTIMATED SOIL RESISTANCE TO DRIVINGESTIMATED SOIL RESISTANCE TO DRIVING

z (m)SRD Estimated

SRD In Field (Re-Created from Driving Record)


EniEniEniEniPRP JACKETPRP JACKET

BACK ANALYSISBACK ANALYSIS

0

100

140

20

40

60

80

120

SRD (kN)10,000 20,000 30,000 40,000 50,000


EniEniEniEni PRP JACKETPRP JACKETPile MakePile Make--up Modification Considerationup Modification Consideration

Considering original pile make upDriving resumption at 99.0 m depth after welding last add-on (P5) using MHU 600B was foreseen too risky due to high estimated Soil resistance expected (>40MN @ 100% Rult) after set-up effect (high dynamic stresses and number of blow count close with the limit, 1000 bl/m).Reducing hammer striking energy would cause hammer unable to overcome soil resistance at this depth. More powerful hammer (MHU 1000, MHU 1700) was not feasible to be used due to stick up problem. MHU800S was proposed as back-up of MHU600B to drive the last two add-ons (No stick-up problem) and to increase slightly the probability to resume driving at 99m.Based on Pile monitoring (Driving records) of existing Platforms of the Field, a Soil set-up analyses were conducted by Geotechnical specialists to estimated a more accurate SRD in continuous driving and after a long delay (24 h set-up).Final decision was to reduce the risk to have refusal and a new pile make up was advised.Considering new pile make up This configuration moved up last intermediate penetration from 99.0 m to 94.0 m. It was certain that MHU 600B able to resume and complete the driving of last add-on (P5) without any problem. However, this would reduce total length assembled pile and some pile would not reach target penetration.

PRP JACKETPRP JACKETMain Pile Configuration Main Pile Configuration -- ORIGINALORIGINALPeople, Ideas, Energy

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Original Lead Section Length

Make-upLength

[m]Cut-off

[m]

Lead Section 69.05 -1

1

1

6.212

1st Add-on 39.40

2nd Add-on 34.50

3rd Add-on 32.20

4th Add-on 31.10


EniEniEniEni PRP JACKETPRP JACKETMain Pile Configuration Main Pile Configuration -- MODIFIEDMODIFIED

Modified Lead Section Length

Make-upLength

[m]Cut-off

[m]

Lead Section 63.81 -1

1

1

5.242

1st Add-on 39.40

2nd Add-on 34.50

3rd Add-on 32.20

4th Add-on 31.10


EniEniEniEni FLARE TRIPODFLARE TRIPODFOUNDATION PILES INFORMATIONFOUNDATION PILES INFORMATION


Conf.Conf.TotalTotal

LengthLength

345345 153.6m153.6m



84 m84 m(84.7m)(84.7m)

D62-22, D80-23,D100-13, IHCS280, MHU 270T

Flare TripodFlare Tripod(3 No. Piles)(3 No. Piles)

True Batter = True Batter = 7.817.81

30,30,0.751.50.751.5


++5 Add 5 Add --onsons

Legend :Available Spread HammerProposed and Adopted HammerAnalyzed Hammer

FLARE TRIPODFLARE TRIPODPile Configuration Pile Configuration -- ORIGINALORIGINALPeople, Ideas, Energy

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Make-upLength

[m]Cut-off

[m]

Lead Section 69.50 -

1

1

1

1

5th Add-on 16.50 3.292

1st Add-on 22.00

2nd Add-on 17.65

3rd Add-on 17.654th Add-on 17.65

Original Length


EniEniEniEni FLARE TRIPODFLARE TRIPODPile Configuration Pile Configuration -- MODIFIEDMODIFIED

Modified Length

Make-upLength

[m]Cut-off

[m]


1

1

1

1

5th Add-on 16.50 3.292

1st Add-on 22.00

2nd Add-on 17.65

3rd Add-on 23.654th Add-on 11.65

SRD Lower BoundSRD Upper BoundSRD Ultimate Static Capacity API 2000


EniEniEniEni FLARE TRIPODFLARE TRIPODESTIMATED SOIL RESISTANCE TO DRIVINGESTIMATED SOIL RESISTANCE TO DRIVING

SRD (kN)

6

0

30

64

88

z (m)

12

18

24

36

42

48

56

72

80

5,000 10,000 15,000 20,000 25,000

SRD Ultimate Static Capacity API 1986SRD Lower BoundSRD Upper Bound

FLARE TRIPODFLARE TRIPODPile MakePile Make--up Modification Considerationup Modification Consideration

Considering original pile make upDriving resumption at 52m depth after welding of P5 section using D100 was foreseen too risky (premature refusal) due to high estimated Soil resistance expected (>10MN @ 100% Rult) after full set-up effect. A dense sand layer ( 3454m) was present in site. Also the driving resumption at 68m depth after welding of last section (P6) using D100 was foreseen too risky (premature refusal) due to high estimated Soil resistance expected (>12MN @ 100% Rult) after full set-up effect.Using diesel hammer with the max. striking energy was foreseen unable to overcome soil resistance at these depth. More powerful and light hammer such as IHC S280 was proposed and used as back-up of Delmag D100 to drive the last two add-ons (No stick-up problem) and to reach the target penetration.Final decision was to reduce the risk to have refusal and a new pile make up was advised plus the renting of IHC hammer.Considering new pile make up This configuration moved down intermediate penetration from 52m to 58m beyond the critical sand layer. In this way the D100 increased the probability to be able to resume P5 section driving. Whilst, using the powerful hydraulic hammer IHC S280 as back-up of D100 for resume driving of last add-on (P6) reduced the risk to have a premature refusal and guarantied the target penetration (83m) achievement.


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EniEniEniEni PEDESTRIAN TRIPODPEDESTRIAN TRIPODFOUNDATION PILES INFORMATIONFOUNDATION PILES INFORMATION


Conf.Conf.TotalTotal

LengthLength

345345 149.9m149.9m



79.5 m79.5 m(80.2m)(80.2m)

D62-22,D80-23D100-13,IHCS 280

Pedestrian Pedestrian TripodTripod(3 No. Piles)(3 No. Piles)

True Batter = True Batter = 7.817.81

30,30,0.751.50.751.5


++5 Add 5 Add --onsons

Legend :Available Spread Hammer

Proposed and Adopted Hammer


EniEniEniEni PEDESTRIAN TRIPODPEDESTRIAN TRIPODPile Configuration Pile Configuration

Make-upLength

[m]Cut-off

[m]


1

1

1

1

5th Add-on 16.50 3.092

1st Add-on 20.00

2nd Add-on 17.00

3rd Add-on 17.00

4th Add-on 17.00


EniEniEniEni PEDESTRIAN TRIPODPEDESTRIAN TRIPODESTIMATED SOIL RESISTANCE TO DRIVINGESTIMATED SOIL RESISTANCE TO DRIVING

SRD Ultimate Static Capacity API 1986SRD Ultimate Static Capacity API 2000SRD Lower BoundSRD Upper Bound60% SRD Ultimate Static Capacity API 2000

PEDESTRIAN TRIPODPEDESTRIAN TRIPODOriginal Pile MakeOriginal Pile Make--up Considerationup Consideration

Considering original pile make upDriving resumption at 64m depth after welding of last section (P6) using D100 was foreseen too risky (premature refusal) due to high estimated Soil resistance expected (>7MN @ 100% Rult) after full set-up effect. Only clay layers were present in site. Using the diesel hammer with the max. striking energy would cause hammer unable to overcome soil resistance at this depth. More powerful and light hammer such as IHC S280 was proposed and used as back-up of Delmag D100 to drive the last add-on (No stick-up problem) and to reach the target penetration (80m).Final decision was to reduce the risk to have refusal and using the original pile make up the renting of IHC hammer was advised.


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EniEniEniEni PRP JACKET PRP JACKET -- PILES DRIVINGPILES DRIVING


EniEniEniEni FLARE TRIPOD FLARE TRIPOD -- PILES DRIVINGPILES DRIVING

WHAT TO DO IN CASE OF REFUSAL?WHAT TO DO IN CASE OF REFUSAL?

Change with the powerful hammer (if any) If refusal occurs far away from final penetration, jetting or drilling

shall be performed (if available) Close to final penetration, drilling could be counter productive, since

it removes the tip resistance In this case drilling and grouting shall apply Drilling involves a costly preparation of equipment Drilling implies full commercial coverage, since a few days could be

lost on each pile, all on critical path Drilling feasible on all main piles but complex on skirt pile ?


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EXAMPLE : PILE STICKEXAMPLE : PILE STICK--UP CALCULATIONUP CALCULATION


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DATA

Conductor PileO.D. = 30 = 762 mmW.T. = 1 = 25.4 mm (uniform WT)

Pile Length = 60 mFy = 345 MPa (EN 10025 S355JO)True Batter = Vertical (1 include tolerance)

Hammer Data :Type = MHU 270T (above water,

without under water ballast)Weight,mh = 444.4 kNC.o.G = 2.5 m

Resulting Free Standing Length :Rfs = 60 (5 +20 + 5)

= 30 m

Resulting Free Standing Length (Rfs)

Cantilever Section

(+)5.0 m

(-)20.0 m

Penetration = 5 m

HammerSleeve

C.o.G


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LOADS CALCULATIONBending MomentM = mh x (Rfs + C.o.G.) x sin 1 + mL x (Rfs / 2) x sin 1

Where : mL = weight of pile (kN)= 0.25 (OD2 ID2) x Rfs x 7850 kg/m3= 0.25 (0.7622 0.71122) x 30 x 7850= 13842.23 kg

mL = 135.792 kN

M = 444.4 x (30+2.5) x sin1 + 135.792 x (30/2) x sin1M = 287.387 kN-m

Minimum bending moment based on API requirement:M = 2% x mh x Rfs

= 2% x 444.4 x 30M = 266.64 kNm

Therefore, adopt M = 287.387 kNm

Axial (Compressive) LoadN = (mh + mL) x cos 1

= (444.4 + 135.792) x cos 1N = 580.104 kN

1

C.o.G

mh

mL

mh.cos

mh.sin

mh

mL.cos

mL.sin

mL

ACTUAL STRESSES CALCULATION

SMfb =

( )44 IDODOD

321 =S

( )44 7112.0762.00.762

321 =S

2b kN/m 27,3700.0105

287.387f ==

MPa 27.370fb =

Actual Bending Stress

Where ;

3m 0.0105S =

Actual Compressive Stress

( ) 222a kN/m 98690.71120.7620.25 580.104ANf ===MPa 9.869fa =


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ALLOWABLE STRESSES CALCULATION

y

y

y F20,680

tD

Fy10,340

59.94F

20,680

29.97F

10,340

301

30tD

===

==

( ) MPa 18.067242.30723206,00012

Kl/r23E12F 2

2

2

2

a ===

Allowable Compressive Stress

I = 0.00399 m4A = 0.25 (0.7622 0.71122) A = 0.0588 m2

( )44 0.71120.762641 =I

Where :


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COMBINED STRESSES CALCULATION

1.0 0.54518.0679.869

Ff

a

a ==

b'e

a

bm

a

a

FFf

1

fCFf

+ ( ) 22

2

2'e 242.30723

206,00012Kl/r23

E12F =

=

MPa 18.067F'e =

1.0 0.778259.639

18.0679.8691

27.370118.0679.869 =

+

1.0 0.154259.63927.370

3450.69.869

Ff

0.6Ff

b

b

y

a =+=+

1.0 0.652259.63927.370

18.0679.869

Ff

Ff

b

b

a

a =+=+d )

Where :

a )

b )

c )


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RESIDUAL DYNAMIC STRESS CALCULATION

Total Static Stress:fs = fa + fb

= 9.869 + 27.370 = 37.239 MPa

Residual Dynamic Stress:Rf dyn = Fy fs

= 345 37.239 = 307.761 MPa

Percentage of Residual Dynamic Stress,% Rf dyn = (307.761 / 345) x 100%

= 89.21 %


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The above calculation calculates static stress (fs) only. The next steps are :Final Check , If fs + f dyn SMYS (OK) and

f dyn 80% 90% SMYS (OK)Where f dyn is the compressive stress at cantilever section, taken from driveability analysis (GRLWEAP output).


EniEniEniEni REFERENCESREFERENCES

American Petroleum Institute API RP 2A-WSD Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms -Working Stress Design.

American Institute of Steel Construction (AISC), Manual of Steel Construction.

Brochure Diesel Hammer by Delmag. Brochure Hydraulic Hammer by Menck. Brochure Steam Hammer by Menck. Brochure Vibratory Hammer by ICE. European Norm (EN10025-95): Technical Specifications of Coils and Strips,

Sheet and Heavy Plates. GRLWEAP Handbook, 2005 Version. Pile Driveability Course, PT. Saipem Indonesia, Jakarta 2005 (Parisi, Saipem

S.p.A.). SMS Work Instructions, Doc.CR-SMS-INST-305-E, Criteria for Refusal of

Offshore Installation Platforms Pile Driving, 2006 (Parisi, Saipem S.p.A.) Stevens, R.S., E.A. Wiltsie and T.H. Turton Evaluating Pile Driveability for

Hard Clay, Very Dense Sand, and Rock XIV OTC, Houston, 1982

Documents

Piling Workshop Rev.a Singapore