SHORT COURSESHORT COURSEONON

DESIGN AND CONSTRUCTION DESIGN AND CONSTRUCTION OF PILE FOUNDATIONSOF PILE FOUNDATIONS

Prof.(Dr.) SUDHENDU SAHAChartered Professional Engineer

Civil Structural Geotechnical Consultant

Formerly

Professor and Head of The Dept. of Civil Engineering,

DEAN of Research Consultancy & Industry Institute Interaction,

Bengal Engineering and Science University, Sibpur

PILE FOUNDATIONPILE FOUNDATION

APPLICATIONS OF PILESAPPLICATIONS OF PILES

High Vertical LoadsHigh Vertical LoadsUplift ForcesUplift ForcesLateral LoadsLateral LoadsInclined LoadsInclined Loads

Water Front StructuresWater Front StructuresTransmission TowersTransmission TowersBridge FoundationsBridge Foundations

Transfering Loads to Deeper LayerTransfering Loads to Deeper LayerSeismic ForcesSeismic Forces

Foundations of MachinesFoundations of MachinesTall Structures etcTall Structures etc

BORED PILE WALL

Classification of PilesClassification of Piles

Based on MaterialsBased on MaterialsMethod of InstallationMethod of Installation

Method of Load TransferMethod of Load Transfer

Materials – Materials – TimberTimber SteelSteel

ConcreteConcrete CompositeComposite

Installation Installation – – DrivenDriven BoredBored

Load Transfer – Load Transfer – FrictionFriction End BearingEnd Bearing

Factors to Choice of TypesFactors to Choice of Types Type of constructionType of construction..

Availability of pile typesAvailability of pile types Anticipated pile loads.Anticipated pile loads.Driving characteristicsDriving characteristics quipment available quipment available

Time availableTime available Accessibility of site Accessibility of site Comparative costsComparative costs

PRECAST CONCRETE PILESPRECAST CONCRETE PILES

BASED ON METHOD OF INSTALLATIONBASED ON METHOD OF INSTALLATION

DRIVEN PILESDRIVEN PILESPRECAST OR CAST IN SITUPRECAST OR CAST IN SITU

BOREDBORED PILES PILESCAST IN SITU PILESCAST IN SITU PILES

BASED ON LOAD TRNSFER BASED ON LOAD TRNSFER MECHANISMMECHANISM

FRICTION PILESFRICTION PILESEND BEARING PILESEND BEARING PILES

PILE DRIVING RIGPILE DRIVING RIG

SIMPLEX PILING RIGSIMPLEX PILING RIG

DROP HAMMER ON PILEDROP HAMMER ON PILE

PREMIX CONCRETE USEDPREMIX CONCRETE USED

STAGES OF INSTALLATION OF STAGES OF INSTALLATION OF FRANKI PILEFRANKI PILE

TYPICAL BORED PILING RIGTYPICAL BORED PILING RIG

BORED PILEBORED PILE

ROTARY BORED PILINGROTARY BORED PILING

BORED CAST INSITU RCC PILESBORED CAST INSITU RCC PILES

STAGES OF CONSTRUCTION OF STAGES OF CONSTRUCTION OF UNDER REAMED PILEUNDER REAMED PILE

UNDER-REAMING RIGUNDER-REAMING RIG

TREMIE CONCRETINGTREMIE CONCRETING

CONTINOUS FLIGHT AUGER PILESCONTINOUS FLIGHT AUGER PILES

Construction Problem Construction Problem For Bored PileFor Bored Pile

1. Caving in of Bore Hole Wall

2. Aggregate Separation during Concreting

3. Falling Concrete may get Jammed in Reinforcement

4. Encrustation of Hardened Concrete

5. Clay Lumps may fall into Hole

Effects of Installation Effects of Installation of Bored Pilesof Bored Piles

Softening of Surrounding SoilSoftening of Surrounding Soildue todue to

Absorption of Water from ConcreteAbsorption of Water from ConcreteSeepage of WaterSeepage of Water

Water Poured into Bore HoleWater Poured into Bore HoleSoil Sludge Deposited at TipSoil Sludge Deposited at Tip

Caving of holeCaving of holeAggregates SeparationAggregates Separation

Buckling of ReinformentsBuckling of Reinforments

Effects of InstallationEffects of Installation of Driven Piles in CLAY of Driven Piles in CLAY

Remolding of SoilRemolding of SoilAlteration of StressAlteration of Stress

Dissipation of Excess Pore PressuresDissipation of Excess Pore PressuresStrength Regain in Long TermStrength Regain in Long Term

NECKING IN PILENECKING IN PILE

NECKING IN PILENECKING IN PILE

BEHAVIOUR OF PILESBEHAVIOUR OF PILES

1. Depends on Load Transfer Mechanism

2. Type and Properties of Soil

3. Full Friction Capacity develops for much Smaller Penetration

4. Full Point Resistance develops only forLarge Penetration of 10% of Diameter

LOAD TRANSFER MECHANISM

FRICTION PILE

END-BEARING PILEEND-BEARING PILE

UPLIFT OF PILEUPLIFT OF PILE

VERTICAL LOAD CAPACITY OF PILEVERTICAL LOAD CAPACITY OF PILE

Static Formula

Using Properties of Soil

Qult = Ab (9Cb + pd Nq ) +

d (iCi + Ki. pdi .tan)li

ADHESION FACTOR OF PILE IN CLAYADHESION FACTOR OF PILE IN CLAY

Consistency N value Cu Values of kN/m2 Bored Piles Driven PilesSoft to very soft < 4 25 0.7 1.0Medium 4 to 8 25 to 50 0.5 0.7 to 0.4Stiff 8 to 15 50 to 100 0.4 0.4 to 0.3Stiff to hard > 15 > 100 0.3 0

BEARING CAPACITY FACTOR BEARING CAPACITY FACTOR

Meyerhof Formula in Cohesionless Soil using SPT Values

50.040)( s

pb

u

ANA

d

LNkNQ

N = average N-value at pile toe. Lb = length of penetration of pile in the bearing strata

in m. N = average N-value along the pile shaft. 

PILE CAPACITY USING PILE CAPACITY USING SCPT DATASCPT DATA

  QQUU = C = C

kdkd A Abb + 2 f + 2 fss A Ass

DYNAMIC FORMULA _ HILEY FORMULADYNAMIC FORMULA _ HILEY FORMULA

Qu = W h / ( S + 0.5 C )= efficiency of blow = ( W + P e2 ) / ( W + P ) for W > P e = ( W + P e2 ) / (W + P ) - ( ( W - P e ) / (W + P ) )2 , for W<P.e C = C1 + C2 + C3

Elastic Comp. Of Pile C1 = 0.2 – 0.25 cm.,

Elastic comp. of head assembly C2 = Qu L/ApEp ,

Elastic Comp. Of Soil C3 = 0.25 cm.

 

 

SIMPLEX FORMULASIMPLEX FORMULA

36.254.2

Lx

P

WHx

L

NR pu

W = weight of pile hammer in kN. H = height of free fall in m, L = length of pile, P = average set in cm for last four blows

Negative Skin Friction on PileNegative Skin Friction on PileWHEN PILE TIP MOVEMENT RESISTEDWHEN PILE TIP MOVEMENT RESISTED

 

1. Consolidation of soil under the weight of recent fill

2. Land subsidence due to lowering of ground water table

3. Reconsolidation of soil around pile disturbed by driving.

EFFECT OF SPECING ON EFFECT OF SPECING ON PILE GROUP CAPACITYPILE GROUP CAPACITY

FACTORS AFFECTING ULTIMATE FACTORS AFFECTING ULTIMATE CAPACITY OF PILE GROUPCAPACITY OF PILE GROUP

OVERLAPPING OF STRESS

METHOD OF INSTALLATION

TYPE OF SOILS

LENGTH AND SPACING

LOADTRANSFER MECHANISM

PILE GROUP CAPACITYPILE GROUP CAPACITYConverse-Labarre formula Converse-Labarre formula Group Efficiency

mn

mnnm )1()1(

901

PILE GROUP CAPACITY IN PILE GROUP CAPACITY IN LAYERED SOILLAYERED SOIL

PILE GROUP CAPACITY IN CLAYPILE GROUP CAPACITY IN CLAY

QQgguu = BL C = BL C

bbNNcc + 2 (B+L). D. C + 2 (B+L). D. Cuu

  

Settlement of Pile Group in ClaySettlement of Pile Group in Clay

S = S = h hii m mvivi ppii

  

LATERAL LOAD CAPACITY OF PILELATERAL LOAD CAPACITY OF PILE

Sources of Lateral Loading

   Earth pressures on retaining walls

  Wind Loads and Seismic Loads

  Impact Loads from Ships (Berthing, waves etc. )

  Eccentric Loads on Columns

  Slope movements

  Cable forces on transmission towers

 

LATERAL LOAD ON VERTICAL LATERAL LOAD ON VERTICAL PILEPILE

LATERAL LOAD ON PILE GROUPLATERAL LOAD ON PILE GROUP

LATERAL PILE CAPACITYLATERAL PILE CAPACITYDEPENDS ONDEPENDS ON

PILE DIAMETER AND LENGTHPILE DIAMETER AND LENGTHRELATIVE STIFFNESSRELATIVE STIFFNESS

LATERAL SUPPORT NEAR GROUNDLATERAL SUPPORT NEAR GROUNDBOUNDARY CONDITIONSBOUNDARY CONDITIONS

RIGID & FLEXIBLE PILERIGID & FLEXIBLE PILE

Long Flexible Pile Le > 4T or 4R

Short Rigid Pile Le < 4T or 4R

T = (EI/k1)0.2 for coarse grained soil

R = (EI/k2 )0.25 for fine grained soil

SHORT AND LONG PILESSHORT AND LONG PILES

Values of Constant k1 (IS:2911)

 

Soil Type(coarse grained soil)

N-value Values of k1

Dry Submerged

Loose SandMedium SandDense SandVery Loose Sand

2  – 4 4 - 10 10 - 35 < 2

o.26 0.1460.775 0.5252.075 1.425 -- 0.0406

Values of Constant kValues of Constant k22 (IS:2911) (IS:2911)

  Soil Consistency(fine grained soil)

Unconfined compression strength qu

in kg/cm2

Values of k2

kg/m2

SoftMedium StiffStiffVery Stiff 

0.20 to 0.40 1 to 2 2 to 4 More than 4

7.75 48.80 97.50 195.50

DEPTH OF FIXITYDEPTH OF FIXITY

SAFE LATERAL PILE CAPACITYSAFE LATERAL PILE CAPACITY

Y = IE

LLHy f

12

31

ULTIMATE LATERAL CAPACITY IN CLAYULTIMATE LATERAL CAPACITY IN CLAY

ULTIMATE LATERAL CAPACITY IN SANDULTIMATE LATERAL CAPACITY IN SAND

METHODS OF IMPROVING LATERAL CAPACITYMETHODS OF IMPROVING LATERAL CAPACITY

LOAD DISTRIBUTION IN PILE GROUPLOAD DISTRIBUTION IN PILE GROUP

DEPENDS ON

TYPE OF SOIL

SIZE AND RIGIDITY OF CAP

NUMBER OF PILES

LAYOUT OF PILES

MAGNITUDE OF SETTLEMENT

LOADS ON PILE IN GROUPLOADS ON PILE IN GROUP

22 y

yM

x

xM

n

QQ xym

STRUCTURAL DESIGN OF PILESTRUCTURAL DESIGN OF PILE

Pu = 0.4fckAc + 0.6fsyAsc

MACHINE FOUNDATION ON PILESMACHINE FOUNDATION ON PILES 

(a)       * IF SAFE BEARING CAPACITY OF SOIL IS EXCEEDED BY LOADING

* TO INCREASE NATURAL FREQUENCY OF FOUNDATION AND DECREASE ITS AMPLITUDE OF VIBRATION

©* SEISMIC CONSIDERATIONS OR SENSITYVITY OF MACHINE FOUNDATION NECESSITATES PILES.

DESIGN CRITERIADESIGN CRITERIA

NATURAL FREQUENCY

AMPLITUDE OF OSCILLATION

STABILITY

BASIC DEFINITIONS

PERIOD OF MOTION FREQUENCYNATURAL FREQUENCY

AMPLITUDE OF MOTIONFREE VIBRATIONFORCED VIBRATION

RESONANCEDAMPING

DYNAMIC RESPONSE OF PILESDYNAMIC RESPONSE OF PILES

Pile is vertical, elastic Pile is vertical, elastic and circular in section and circular in section..

It is a floating pile.It is a floating pile.

It is perfectly connected to soil.It is perfectly connected to soil.

MAGNIFICATION FACTOR VS MAGNIFICATION FACTOR VS FREQUENCY RATIOFREQUENCY RATIO

FOR CONSTANT PEAK FORCE OF EXCITATIONFOR CONSTANT PEAK FORCE OF EXCITATION

RESPONSE SYSTEM WITH RESPONSE SYSTEM WITH ROTATING UNBALANCEROTATING UNBALANCE

PILE STIFFNESS AND DAMPINGPILE STIFFNESS AND DAMPING

Kw = (EA/r0 ) . fw 1

and

Cw = (EA/Vs) . fw 2

AMPLITUDE AT OPERATING FREQUENCYAMPLITUDE AT OPERATING FREQUENCY

222

2

21.

rDr

r

M

emA ez

STIFFNESS AND DAMPING PARAMETERSSTIFFNESS AND DAMPING PARAMETERS

STIFFNESS AND DAMPING STIFFNESS AND DAMPING PARAMETERSPARAMETERS

STIFFNESS AND DAMPING STIFFNESS AND DAMPING PARAMETERSPARAMETERS

STIFFNESS AND DAMPING STIFFNESS AND DAMPING PARAMETERSPARAMETERS

CONSTRUCTION CONSTRUCTION MONITORING AND QUALITY MONITORING AND QUALITY

ASSURANCEASSURANCE

PILE LOAD TESTPILE LOAD TEST

Pile Load Testing is the Pile Load Testing is the Most Positive Method of Most Positive Method of

Determining Pile CapacityDetermining Pile Capacity

INITIAL PILE LOAD TESTINITIAL PILE LOAD TEST

ROUTINE PILE LOAD TESTROUTINE PILE LOAD TEST

STATIC LOAD TESTSTATIC LOAD TEST

Objective of Load Test

To establish load-settlement relationships in the pile-soil system

To determine capacity of the pile-soil system, and

To determine load distribution in the pile-soil system.

Static Load Test - Test SetupStatic Load Test - Test Setup

Reaction Beam Stiffeners

PlateLoad Cell

Spherical Bearing

Ram

Hydraulic JackBourdon Gage

Dial GageLVDT

Mirror

Scale

Test Pile

Grade

Bracket Attached to PileWire

LOAD TEST KENTLEDE LOAD TEST KENTLEDE ARRANGEMENTARRANGEMENT

LOAD TEST SET UPLOAD TEST SET UP

Conventional Arrangement for Pile Load Test

 

ARRANGEMENT OF HYDRAULIC JACKARRANGEMENT OF HYDRAULIC JACKDATUM BAR & DIAL GAUGESDATUM BAR & DIAL GAUGES

Typical Arrangement for Load Typical Arrangement for Load Testing a Pile or Drilled ShaftTesting a Pile or Drilled Shaft

Reaction BeamReaction Beam

JackJackDial

GageDial

Gage

Test Pile or Drilled ShaftTest Pile or Drilled Shaft

Support Beam

Support Beam

Anchor Pile or Drilled ShaftAnchor Pile or Drilled Shaft

LOAD TEST WITH ANCHOR PILESLOAD TEST WITH ANCHOR PILES

TYPICAL PILE LOAD TEST FRAME TYPICAL PILE LOAD TEST FRAME WITH REACTION PILESWITH REACTION PILES

LOADING FRAME WITH LOADING FRAME WITH KENTLEDGEKENTLEDGE

PILE LOAD TEST METHODSPILE LOAD TEST METHODS

Maintained Equilibrium Load Test   

Constant Rate of Penetration Test

Cyclic Load Test.

PLOTS OF Load vs Settlement,PLOTS OF Load vs Settlement,Load vs Time & Time vs SettlementLoad vs Time & Time vs Settlement

Load - Settlement GraphLoad - Settlement Graph

Ultimate Bearing Capacity

Load

Set

tlem

ent

LOAD SETTLEMENT CURVELOAD SETTLEMENT CURVE

CRITERIA FOR DETERMINATION OFCRITERIA FOR DETERMINATION OFALLOWABLE LOAD ON PILEALLOWABLE LOAD ON PILE

One-half of Ultimate load indicated by double One-half of Ultimate load indicated by double tangent methodtangent method

Two-third of Load for 12 mm total settlementTwo-third of Load for 12 mm total settlementTwo-third of Load for 6 mm Net SettlementTwo-third of Load for 6 mm Net SettlementHalf of Load for Settlement of 10% of DiaHalf of Load for Settlement of 10% of Dia

Whichever is the lowestWhichever is the lowest

SEPARATION OF FRICTION ANDSEPARATION OF FRICTION ANDPOINT RESISTANCEPOINT RESISTANCE

LATERAL LOAD TEST ON PILELATERAL LOAD TEST ON PILE

PULL OUT TESTPULL OUT TEST

LATERAL DYNAMIC LOAD TESTLATERAL DYNAMIC LOAD TESTFREE VIBRATION TESTFREE VIBRATION TEST

FORCED VIBRATION TESTFORCED VIBRATION TEST

QUALITY CONTROLQUALITY CONTROL

Whether Pile Tip Has reached Firm StratumWhether Pile Tip Has reached Firm StratumOR Specified Termination DepthOR Specified Termination Depth

Whether Concreting done ProperlyWhether Concreting done ProperlyWhether load – Settlement Characteristics Whether load – Settlement Characteristics

SatisfactorySatisfactory

INTEGRITY TESTINGINTEGRITY TESTING

Check for Pile DiscontinuityCheck for Pile Discontinuitywhich may occur due towhich may occur due to

Encrustation of ConcreteEncrustation of ConcreteJamming of ConcreteJamming of ConcreteFalling of Clay LumpsFalling of Clay Lumps

CHECKING OF INTEGRITYCHECKING OF INTEGRITYBYBY

EXCAVATION OF PILE SHAFTEXCAVATION OF PILE SHAFT

EXPLORATORY BORING THROUGH PILE SHAFTEXPLORATORY BORING THROUGH PILE SHAFT

SONIC TESTSONIC TEST

Osterberg Load Test SetupOsterberg Load Test SetupCell Expansion Telltale

Dial Gage 2

Friction Collar

Dial Gage 1

High Strength Pipe

Shaft Compression Telltale Pile Top (Side Shear) Movement Gage

Reference Beam

Prestressed Concrete Pile

Osterberg Cell Cast Into Pile

Pile Shaft Resistance

Hand Operated Hydraulic Pump with Pressure Gage and Pressure Transducer

Statnamic Load Test SetupStatnamic Load Test Setup

Pressure Chamber

Load Cell

Base Plate Grouted to Foundation

Concrete or Steel Reaction Mass

Loose Granular Fill

Propellant Launching Cylinder

Piston Base

Displacement Measuring Means

Pile or Drilled Shaft

Statnamic Load Test MechanismStatnamic Load Test Mechanism

Load (MN)

0

-1

-4

-2

-3

-5

-60 1 2 3 4 5

Dis

pla

cem

ent

(mm

)

THANK YOUTHANK YOU