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  • Copyright2012byBentleySystems,Inc.Version7.0Revision1

    1.0INTRODUCTION

    1.1OVERVIEW

    PSI,PileStructureInteraction,analyzesthebehaviorofapilesupportedstructuresubjecttooneormorestaticloadconditions.Finitedeflectionofthepiles("Pdelta"effect)andnonlinearsoilbehaviorbothalongandtransversetothepileaxisareaccountedfor.Theprogramusesafinitedifferencesolutiontosolvethepilemodelwhichisrepresentedbyabeamcolumnonanonlinearelasticfoundation.Thestructurerestingonthepilesisrepresentedasalinearelasticmodel.

    PSIfirstobtainsthepileaxialsolution,thenusestheresultinginternalaxialforcestoobtainthelateralsolutionofthepiles.Ingeneral,soilsexhibitnonlinearbehaviorforbothaxialandtransverseloads,thereforeaniterativeprocedureisusedtofindthepileinfluenceonthedeflectionofthestructure.

    1.2PROGRAMFEATURES

    PSIisdesignedtousepileandsoildata,specifiedinaninputfile,inconjunctionwithlinearstructuraldataproducedbytheSACSIVprogram.AmongthefeaturesofPSIarethefollowing:

    1. TubularandHpilecrosssectionssupported.

    2. Pilemayhavevaryingpropertiesalongitslength.

    3. Soilaxialbehaviormayberepresentedbyadhesiondata,nonlinearTZdata,orasalinearspring.

    4. Endbearingeffectsmaybeaccountedfor.

    5. SoillateralbehaviorrepresentedbynonlinearPYcurves.

    6. BasicsoilpropertiesmaybeusedtogeneratethesoilaxialpropertiesintheformofTZcurvesoradhesiondata,endbearingTZdataand/orlateralsoilpropertiesintheformofPYcurves,basedonAPIRP2Arecommendations.

    7. Soilstratificationmaybemodeled.

    8. Mudslideconditionsimulationcapabilities.

    9. Completesoilpropertyplotcapabilities,includingPY,TZandadhesiondata.

    10. Analysisresultsplotcapabilities,includingdeflections,rotations,loads,reactions(soilandpile),andunitycheckratiosplottedalongthepilelength.

    11. Createsuptotwoequivalentlinearizedfoundationsuperelementstobeusedbydynamicanalysesinlieuofpilestubs.

    12. ImplementationofAPIRP2A20Editionsoiladhesion,TZandPYdatagenerationbasedonbasicsoilproperties.

    13. Createsfoundationsolutionfilecontainingpilestressestobeusedforfatigueanalysis.

    14. Allowstheusertodesignateloadcasestobeusedforpilecapacityandcodecheckcalculations.

    ThePileandPile3Dprograms,whicharesubprogramsofPSI,maybeexecutedalonetocalculatethebehaviorofasinglepile.Inadditiontothefeaturesoutlinedabove,thePileprogramhasthefollowingfeatures:

    1. Determinesanequivalentpilestubthatyieldsthesamedeflectionsandrotationsasthesoil/pilesystem.

    2. AllowstheapplicationofforcesandmomentsobtainedfromSACSanalysestocreateapostfiletobeusedforasubsequentfatigueanalysis.

    2.0CREATINGPSIINPUTThenonlinearfoundationmodel,includingthepileandthesoilproperties,isspecifiedseparatefromthemodelinformationinaPSIinputfile.

    TheinterfacejointsbetweenthelinearstructureandthenonlinearfoundationmustbedesignatedintheSACSmodelbyspecifyingthesupportconditionPILEHDontheappropriateJOINTinputline.TheanalysisoptionPImustbespecifiedeitheronthemodelOPTIONSlineordesignatedintheExecutive.

    2.1DEFININGANALYSISOPTIONS

    Pile/SoilinteractionoptionsareinputonthePSIOPTline.

    2.1.1GeneralOptions

    Generaloptionssuchastheupwardverticalaxisandtheunitsarespecifiedincolumns89and1012,respectively.CEmaybespecifiedincolumns1718tohavetheprogramcontinuetheanalysisregardlessoferrorsencounteredintheiterationprocedure.

    2.1.2AnalysisOptions

    Thefinalpilestressanalysisoptionisdesignatedincolumns2324.Thepile/structurecoupledinteractionanalysismaybeskippedbyspecifyingSKincolumns1920.Likewise,thesolutionfinetuningproceduremaybeskippedbyenteringNAincolumns2122.

    2.1.3ConvergenceandToleranceCriteria

    Thedisplacement,rotationandforceconvergencetolerancesaredesignatedincolumns2532,3340and6772,respectively.Themaximumnumberofiterationsforapilehead,if

  • otherthan20,maybespecifiedincolumns4143.Solutioniterationcontinuesuntileachdegreeoffreedomatthepileheadhasconvergedtowithinthespecifiedtolerancesoruntilthemaximumnumberofiterationshasbeenexceeded.Enter'N'incolumn15ifequilibriumrelaxationisnottobeused.Equilibriumrelaxationimprovesthechancesofconvergence.

    2.1.4PileOptions

    Thepileunitweightmaybedesignatedincolumns7380iftheeffectofthepileweightistobeincludedintheanalysis.Thenumberofincrementsthatthepileistodividedintomaybeoverriddenincolumns6264.

    2.1.5OutputOptions

    Thepilestiffnesstables,reducedstiffnessmatrixofthelinearstructureandthereducedforcevectormaybeprintedbyspecifyingPTincolumns4445,4647or4849,respectively.IntermediateiterationresultsandinputdatamaybeprintedbyspecifyingPTincolumns5051and5253,respectively.

    AsampleofthePSIOPTlinespecifyingEnglishunitsandadensityof490follows:

    2.1.5.1CreatingaPileSolutionFile

    Asolutionfilecontainingpileinternalloadsandstressesateachincrementalongthepilemaybecreated.EnteredPPincolumns5455ontheOPTIONSlinetocreateasolutionfiletobereadbytheFatigueprogram.TheinlineSCFoptionusedtofactorstressesmaybespecifiedincolumns5658ontheOPTIONSline.

    Note:TheFTGoptionshouldbespecifiedincolumns5658ifstressesaretobeunfactoredsothatoneoftheinlineSCFoptionsavailableinFatiguemaybeused.

    ThefollowingPSIOPTlineindicatesthatafatiguesolutionfileistobeused.ThestressesarenottobefactoredbecausetheywillbefactoredbytheinlineSCFdesignatedintheFatigueinputfile.

    AnauxiliarydetailpilefilemaybegeneratedbyenteringPFincolumns5455.

    2.1.6DesignatingLoadCasesforPileCapacityandCodeCheck

    Bydefault,allloadcasessolvedinthePSIexecutionareusedtocodecheckandcalculatepilecapacitysafetyfactors.TheusermaydesignatewhichloadcasesaretobeincludedorexcludedforthepurposeofpilecheckandcapacityusingtheLCSELline.

    DesignatewhethertheloadcaseslistedaretobeincludedorexcludedbyenteringINorEX,respectively.Forexample,thefollowingspecifiesthatloadcasesOP08,OP09andEQ01aretobeexcluded.

    2.2DEFININGPLOTOPTIONS

    PlotoptionsaredesignatedonthePLTRQ,PLTPL,PLTLCandPLTSZinputlines.

    2.2.1PlotData

    DatatobeplottedisdesignatedonthePLTRQinputline.Soilinputdata,axialdeflection,axialload,axialsoilreactions,requiredpilethicknessandunitycheckratiomaybeplottedversuspilepenetration.Lateraldeflection,lateralrotation,bendingmoment,shearloadandlateralsoilreactionalongoraboutthepilelocalYandlocalZaxesmaybeplottedversuspenetrationinadditiontotheresultant.

    Bydefault,foranyoftheresultplotoptions,foreachloadcaseaseparateplotisgeneratedforeachpile.PilestobeplottedmaybedesignatedonthePLTPLlinewhileloadcasestoplotmaybedesignatedonthePLTLCline.Alternatively,aplotenvelopeshowingthecriticalvalueforallloadcasesselectedmaybeplottedinsteadbyspecifyinganE(forenvelope)afterthedesiredoption.Plotappearanceoptionssuchasgridlinesandcrosshatchingmaybedesignatedalso.

    Thefollowingrequestssoildataplotsalongwithlateralandaxialdisplacement,pileunitycheckandpileredesignplots:

    2.2.2DesignatingPilestoPlot

    Bydefault,plotsaregeneratedforeachpiledefinedinthePSIinputfile.PilestobeplottedmaybedesignatedonthePLTPLlinebespecifyingthepileheadjointnamesofthepilestobeincludedforplotting.Thefollowingdesignatesthatonlypilesdefinedbypileheadjoints4and8aretobeincludedinplots.

  • 2.2.3DesignatingLoadCasestoPlot

    Bydefault,allloadcasesareincludedforplotgeneration.IfloadcasesarespecifiedonthePLTLCinputline,thenonlyloadcasesspecifiedwillbeincludedforplottingpurposes.ThefollowingdesignatesthatonlyloadcasesOP00andST90aretobeplotted.

    2.2.4OverridingPlotSize

    Thedefaultplotpapersize,charactersize,crosshatchingspacingandnumberofcolorsmaybeoverriddenusingthePLTSZline.

    2.3DEFININGTHEPILE

    Thegeometryandcharacteristicsofpilesandconductorsbelowthepileheads,includingsectionandmaterialproperties,pilebatter,pilechordangle,weightperunitlengthandseveraldimensionoverridesareincludedinthePSIinputfile.

    2.3.1PileSectionProperties

    SectionpropertiesfortubularsectionscanbecalculateddirectlyfromtheoutsidediameterandwallthicknessinputonthePLGRUPlineorcanbedefinedonthePLSECTline.Nontubularsectionsand/ortubularsectionswithuserdefinedstiffnesspropertiesaredefinedusingPLSECTlines.

    WhenasectionlabelisspecifiedonthePLGRUPline,thepropertiesaredeterminedfromtheinputonthecorrespondingPLSECTline.Fortubularsections,thesectionlabelfieldshouldbeleftblankwhensectionpropertiesaretobedeterminedfromtheoutsidediameterandwallthicknessspecifiedonthePLGRUPline.

    WhendefiningsectionpropertiesusingaPLSECTline,theuniquecrosssectionlabelreferencedbyasubsequentPLGRUPlineandthecrosssectiontypearerequiredincolumns814and1618,respectively.Thecrosssectiondimensionsmustbespecifiedincolumns5174.

    ThePSIprogramcalculatesthecrosssectionstiffnesspropertiesbasedonthecrosssectiondimensionsinput.Thecalculatedstiffnesspropertiesmaybeoverriddenincolumns1948.Likewise,theunitweightspecifiedonthePSIOPTmaybeoverriddenincolumns7580.

    ThefollowingdefinesthepilesectionnamedH47asanHsection:

    2.3.2PileGroupProperties

    Pilegrouppropertiessuchasmodulusofelasticity,shearmodulus,andyieldstressarespecifiedontheappropriatePLGRUPline.ThegrouptowhichapileisassignedisdesignatedonthePILEline.

    2.3.2.1PileGroupEndBearingArea

    TheeffectiveendbearingareaisspecifiedonthePLGRUPlineincolumns7580.Theusermayspecifyendbearingareaforeachpilesegmenttomodelasteppedpile.NormallyonlythePLGRUPlinecorrespondingtothebottomsegmentofthepilewillhaveendbearingareaspecified.

    2.3.2.2SegmentedPileGroups

    AseriesofPLGRUPlineswiththesamegrouplabelareusedtodefinethepropertygroupofasegmentedpile.Eachinputlinecorrespondstooneofthesegmentsofthatpilegroup.Materialpropertiesofthesegmentinadditiontothesegmentlengtharerequired.

    Forexample,thefollowingdefinesa200foottubularpilegroupnamedPL1consistingoftwosegments.Thefirstsegmenthasawallthicknessof1.5andyieldof50.0whilethesecondhasawallthicknessof0.75andayieldof36.0.Thelengthofthefirstsegmentis50feetwhilethesecondis150feetlong.Endbearingareaisdefinedforthesecondsegmentonly.

    Note:Thelengthofeachsegmentmustbespecified.Also,althoughthelocalXaxisofthepileisupfromthepileheadjointtowardthereferencejoint,segmentpropertiesareassignedfromthepileheadjointdownalongthepile.Intheaboveexample,thefirst50feetfromthepileheaddownisdefinedas60x1.5.

    2.3.2.3PileGroupSurfaceDimensionOverrides

    Bydefault,theactualdimensionsofthepileareusedtocalculatesoilresistance.Thesurfacedimensionofapilegroup,usedforsoilresistancecalculations,maybeoverriddenonthePLGRUPlineincolumns5869.Fortubularpiles,theODandwallthicknessarerequired,whiletheeffectivewidthanddepthareinputforHsections.

  • 2.3.3DefiningPileElements

    PileelementsarespecifiedonPILElinesfollowingthePILEheaderinputline.Thepileelementisnamedbythepileheadjointinthemodeltowhichitisattached.Thepileheadjointtowhichthepileisattachedisspecifiedincolumns710.Thepilegrouptowhichthepileisassignedisspecifiedincolumns1618.

    Note:PileheadjointsmustbedesignatedassuchintheSACSmodelfilebyPILEHDincolumns5560onthecorrespondingJOINTline.

    ThesoilIDdefiningpile/soilinteractionpropertiesinthelocalXZplaneisdesignatedincolumns6972.IfthesoiltableforlocalXYplaneinteractionisdifferentfromthatoftheXZplane,theapplicablesoilIDmustbespecifiedincolumns7477.

    Thefollowingdefinesapileconnectedtopileheadjoint2.ThepileisassignedtopilegroupPL1andusessoiltableSOL1.

    2.3.3.1PileBatter

    Thepilebatterisdefinedbyeitherabatterdefinitionjointspecifiedincolumns1114orbatterdefinitioncoordinatesspecifiedincolumns2150onthePILEline.Thebatterofthepiledesignatedbelowisdefinedusingthepileheadjointandjoint201.

    Note:Whenspecifyingabatterdefinitionjoint,thebatterdefinitionjointmustbeabovethepileheadjoint.Thepilewillbeorientedsuchthatthepileaxisliesonthelinethroughthebatterdefinitionjointandthepileheadjoint.

    Batterdefinitioncoordinatesareusedtodeterminethepilebatterifnobatterdefinitionjointisspecified.TheglobalX,YandZdistancesfromthepileheadtoanypointaboveitlyingonthepileaxisshouldbeinputincolumns2130,3140and4150,respectively.Forexample,todefineapilebattered1:8intheglobalXZplaneandverticalintheglobalYZplane,battercoordinatevaluesofX=1.0,Y=0.0andZ=8.0shouldbeentered.

    2.3.3.2PileLocalCoordinateSystem

    ThepiledefaultlocalcoordinatesystemisdefinedwiththelocalXaxispointingupwardfromthepileheadjointalongthepileaxisdefinedbythepilebatterjointorbattercoordinates.

    Bydefault,thelocalYandZaxisorientationsareloadcasedependent.Foreachloadcase,thelocalYaxisisautomaticallyorientedsuchthatitcoincideswiththedirectionofmaximumpileheaddeflection.Thefigureontherightillustratesthedefaultlocalcoordinatesystemofthepile.

    TheorientationofthelocalYandZaxesmaybeoverriddenbytheuserbyspecifyingtherotationangleaboutthelocalXaxisincolumns5156onthePILEline.Inthiscase,thelocalYaxiswillnotbealignedinthedirectionofmaximumpileheaddeflectionbutwillbedefinedbytherotationangleasshowninthefigurebelow.

  • Note:ThepileanalysisisdoneinthelocalXZandXYplanes.Formudslidecases,apilerotationangleshouldbeusedinordertoorienteitherthepilelocalXZorXYplaneinthedirectionofthemudslide.

    2.3.4PileClusters

    Pilesdrivenincloseproximitytootherpilescanhaveadifferentcapacityfromasinglepileactingindependently.

    Figure1a.showsapairofpilesincloseproximitytoeachother.Thereisatendencyforpilestoactasaunitinthedirectionofthelinejoiningthecentersofthetwopiles.Therefore,thecombinedresistanceforthetwopilesinthisdirection,islessthandoubletheresistanceofasinglepile.Intheotherdirection,however,thereisnosuchinteractionandthetwopilesbehaveindependently.

    Figure1b.showsaclusteroffourpiles.Inthiscaseallfourpileswillhavereducedresistanceinbothdirections.

    ThebehaviorofsuchclusterscanbemodeledbyreducingthePYcurvesinputforthedirectionswherethepilesactasasystemratherthanindependentpiles.

    2.4MODELINGSOILPROPERTIES

    2.4.1Overview

    PSIallowstheusertospecifythepile/soilresponsetoaxial,lateral,andtorsionalloadsappliedatthepileheadthroughnonlinearloaddeflectioncurves(PYandTZcurves).Axialresistancecanalsobespecifiedintermsoflinearspringratesandsoiladhesionvalues.Inaddition,axialbearingcapacitymaybespecifiedatthepiletipandatarbitrarypointsalongthepile,whenmodelingpileswithvaryingdiameter.Inlieuofpilecapacitycurvesoradhesiondata,thecharacteristicsofthesoilmayalsobespecifiedintermsofbasicsoilproperties(unitweight,shearstrength,etc.),thattheprogramcanusetodevelopthepile/soilresponsebasedonAPIRP2Arecommendations.

    ThePSIprogramrequiresthatthesoilpropertiesbedefinedinaspecificorder,namelyaxialresistance,bearingcapacity,torsionalresistancefollowedbylateralcapacity.Foraxial,bearingandlateralcapacity,thesoilcapacityorpropertiesmaybedefinedatvariouselevationsorsoilstratum.

    Note:Whenmultiplesoilsaretobedefined,allpropertiesofthefirstsoilmustbedefinedbeforeanypropertiesofthenextsoilmaybespecified.

  • 2.4.2SpecifyingElevationsforSoilResistanceCurves

    Withinasoilstratum,thePSIprogramconnectstheinputPYorTZpointswithstraightlinestofullydefinethepile/soilinteractioncurveforarbitrarydisplacementsinthatstratum.Atdepthsbetweenspecifiedsoilstrata,PSIhastheabilitytolinearlyinterpolatebetweencurvesortouseaconstantTZcurve.

    Whenthesoilpropertiesaretobeassumedconstantthroughoutthedepthofasoilstrata,thedistancesfromthepileheadtothetopandbottomofthestratashouldbothbespecified.Thecurvegeneratedisusedfortheentiredepthofthestrata.Whensoilpropertiesspecifiedapplyonlytoaspecificelevation,onlythedistancetothetopofthestratashouldbespecified.Thesoilcurvegeneratedappliesonlythespecificelevationdesignated.

    Soilpropertiesatelevationswithoutresistancecurvesdefinedareobtainedbyinterpolatingbetweenthecurvesdefinedimmediatelyaboveandbelow.Forexample,thefirstSOILAPIAXLlineinthesamplebelow,specifiesthataxialsoilpropertiesfromelevation0.0to30.0areconstant.ThesecondSOILAPIAXLlinestipulatesthattheTZcurvesgenerateddefinessoilpropertiesatelevation60.0.Therefore,axialsoilpropertiesatelevationsbetween30and60willbedeterminedthroughlinearinterpolationbetweenthetwocurves.

    2.4.3SoilAxialResistance

    Foranysoil,thefirstpropertythatmustbedefinedistheaxialresistanceorcapacity.Axialloadsareresistedbydistributedlongitudinalsurfaceshearforcesalongthelengthofthepileandbyendbearingforcesattheendandatintermediatepointswherethepilesouterdiameterchanges.Axialresistanceforaparticularsolimaybespecifiedintermsofeitheralinearaxialspring,adhesion(skinfriction),oraxialloaddeflectioncurves(TZcurves).

    2.4.3.1LinearAxialSpring

    PileheadaxialbehaviormadebemodeledasalinearaxialspringatthepileheadusingtheSOILAXIALHEADinputline.ThesoilIDandthelinearstiffnessofthespringmustbespecifiedincolumns4144and3140,respectively.

    Whenusingapileheadaxialspring,theaxialforceinthepileisassumedtolinearlydissipatefromthepileheadaxialforcetozeroattheendofthepile.Nootheraxialcapacitydataorbearingcapacitydatamaybespecifiedwhenassigninganaxialspringtoapilehead.

    2.4.3.2GeneratingAdhesion&BearingCapacityperAPIRP2A

    PSIcanautomaticallygeneratethepileaxialadhesionorskinfrictionandbearingcapacitybasedonAPIguidelinesfrombasicsoilcharacteristicsinputbytheuser.

    TheSOILAXIALHEADlineisrequiredtogenerateskinfrictionandbearingcapacitiesfrombasicsoilcharacteristics.ThenumberofsoilstratatobedefinedandthesoilIDornamemustbespecifiedincolumns1820and4144,respectively.

    Thepropertiesofeachstratamakingupthesoilarespecifiedimmediatelyfollowingtheheaderlineusingeitherthesand,clayorrocksoilaxialstratalinedesignatedbySOILAPIAXLincolumns112.TheAPIversionisinputincolumn13andthestratalocationlabelSLOCincolumns1417isrequired.Theverticaldistancefromthepileheadtothetopandbottomofthestrataarespecifiedincolumns1924and2530,respectively.Thesoiltypeandthesoilcharacteristicsareinputincolumns3277.

    Note:Eitherasand,clayorrocksoilaxialstratalineisrequiredforeachsoilstratatobedefined.

    Axialadhesioncapacityiscalculatedforeachsoilstratuminput.Beginningatthetopstrata,thelengthoverwhichtheadhesionmustacttodissipatetheaxialloadiscomputed.Ifthislengthislessthanthestratathickness,theaxialloadiscompletelydissipatedinthecurrentstrata.Iftherequiredlengthisgreaterthanthestratathickness,theexcesspileloadintothenextstratabelow.Theprocedureisrepeateduntilallofthepileloadisdissipatedoruntilallstratumhavereachedcapacity.Ifthetotalpileloadhasnotbeendissipated,theexcessloadistransferredbyendbearinguntiltheendbearingcapacityisreached.Ifthetotalaxialloadhasnotbeendissipated,thepilefails.

    Note:Becauseendbearingdataisautomaticallygenerated,noendbearingdatashouldbespecifiedwhengeneratingaxialcapacityautomatically.

    2.4.3.3UserDefinedAdhesionandBearingCapacityData

    AdhesionandbearingcapacitydatamaydirectlyinputbytheuserusingtheSoilAxialAdhesionheaderline(namedSOILAXIALHEAD)andspecifyingthenumberofsoilstratum,theendbearingcapacityandthesoilID/nameincolumns1810,2130and4144,respectively.

    ThedistancebetweenthepileheadandthetopandbottomofeachofthesoilstratummustbespecifiedontheSOILSLOCline(s)immediatelyfollowingtheheaderline.ThesoiladhesiondataforeachstrataisdefinedonthefollowingSoilAxialAdhesionCapacityline(s).

    2.4.3.4GeneratingTZCurves&BearingCapacityperAPIRP2A

    PSIcanautomaticallygenerateaxialloaddeflectioncurves(TZcurves)andbearingloaddeflectioncurves(QZcurves)basedonAPIguidelinesfrombasicsoilcharacteristicsinputbytheuser.

    TheSOILTZAPIHEADlineisrequiredtogenerateTZandQZcurvesfrombasicsoilcharacteristics.ThenumberofsoilstratatobedefinedandthesoilIDornamemustbespecifiedincolumns1820and4144,respectively.

    Thepropertiesofeachstratamakingupthesoilarespecifiedimmediatelyfollowingtheheaderlineusingeitherthesand,clayorrocksoilaxialstratalinedesignatedbySOILAPI

  • AXLincolumns112.TheAPIversionisinputincolumn13andthestratalocationlabelSLOCincolumns1417isrequired.Theverticaldistancefromthepileheadtothetopofthestrataisspecifiedincolumns1924.Thedistancefromthepileheadtothebottomofthestratamaybeoptionallyinputincolumns2530.Thesoiltypeandthesoilcharacteristicsarerequiredincolumns3277.

    Note:Becauseendbearingdataisalsoautomaticallygenerated,noendbearingdatashouldbespecifiedwhengeneratingaxialcapacityautomatically.

    2.4.3.5GeneratingTZCurvesUsingCPTBasedMethods

    PSIcanautomaticallygenerateTZandQZcurvesbasedononeofthefourAPIrecommendedCPTbasedmethods,namelySimplifiedICP05,OffshoreUWA05,Fugro05andNGI05.ThechosenmethodisinvokedbyspecifyingoneofICP,UWA,FUGandNGIinColumns6264oftheSOILTZAPIHEADline.ACPTtooldiametershouldalsobespecifiedinColumns6672.ThesubsequentstrataaredefinedusingtheSOILAPIAXLlineswithCPTenteredinColumns3234.Inadditiontothedatarequiredforthedefinitionofthestratumlocationandtype,thefollowingsoilpropertiesaredefinedforeachCPTstratum(i)theconetipresistanceinColumns4247,(ii)theconstantvolumeinterfacefrictionangleinColumns5459and(iii)thesubmergedmassdensityinColumns4853.ThecoefficientoflateralearthpressuremaybespecifiedoptionallyforusagewiththeSimplifiedICPmethodinordertocalculatethesandrelativedensityusingtheTicinoSandrelationship.Ifthecoefficientoflateralearthpressureisnotspecified,thesandrelativedensityiscalculatedusingtheLunneandChristoffersonformula.

    ItshouldbenotedthattheunitskinfrictionsthataregeneratedusingCPTbasedmethodsaredependentonpilegeometry.Furthermore,theunitskinfrictionsgenerallydifferintensionandcompression.

    InaccordancewithAPIrecommendation,theunitendbearingisassumedtobefullymobilizedatz/D=0.1.Theunitskinfrictionisassumedtobemobilizedat0.1inches,consistentwithpreviousAPIrecommendationsforcohesionlessstrata.AzfactormaybespecifiedforusagewithCPTbasedmethodsusingColumns3440oftheSOILTZAPIHEADline.

    Thefollowing(metric)exampleillustratestwoCPTstrata,thelatterofwhichhasdefinedaconetipresistanceof5.0MPaandaconstantvolumeinterfacefrictionangleof28degrees.TheCPTtooldiameteris3.56cmandtheaxialresistancecurvesaretobeconstructedusingtheSimplifiedICP05method.

    2.4.3.6ApplyingAPIGeneralScourRecommendations

    TheAPIguidelinesdefinegeneralscourasseabederosionduetowaveandcurrentaction.Generalscourcanaffectboththeaxialandlateralsoilresistance,duetodecreasesinconetipresistanceandverticaleffectivestress.

    APIrecommendationspresenttwomethodsfortakinggeneralscourintoaccountwhencalculatingaxialresistance.Twomethodsarepresented,henceforthreferredtoastheNNIandFugromethods.Bothmethodsinvolvethedeterminationofascourreductionfactor,,whichfactorstheoriginalconetipresistancetogiveafinalconetipresistance:

    TheNNImethod,specifiesthatthescourreductionfactoristheratioofthefinalverticaleffectivestresstotheoriginalverticaleffectivestress.TheFugromethodprovidesamorecomplicatedformulafor,andisrecommendedforhighgeneralscourdepthsandnormallyconsolidatedsands.

    TherearealsoAPIrecommendationsfortakinggeneralscourintoaccountwhencalculatinglateralresistance.Thescourbringsaboutareductioninlateralsupportdueto(i)adecreasedverticaleffectivestressand(ii)adecreasedinitialmodulusofsubgradereaction(ES).

    TheSCOURlineprovidesameanstospecifyadepthforgeneralscour.ThegeneralscourdepthisappliedtoallpilesinthemodelandisspecifiedinColumns914oftheSCOURline.TheaxialsoilresistanceisreducedbygeneralscouronlyforsoilsthathavebeendefinedusingCPTdata.Bydefault,theNNImethodisused,althoughtheFugromethodmaybeusedbyspecifyinganFinColumn7oftheSCOURline.ThelateralsoilresistanceisreducedforallcurvesgeneratedusingAPIrecommendations.Scourrecommendationsshouldonlybeappliedtocohesionlessstrata.Forthisreason,thegeneralscourdepthislimitedbythetopdepthofthefirstclaystratumoftherelevantlateralsoiltable.

    UsergeneratedTZ,QZandPYcurvesareunaffectedbythegeneralscourspecification.

    2.4.3.7UserDefinedTZCurves

    TZcurvesdefiningthesoilaxialresistancemaybeinputdirectlybytheuser.TheSOILTZAXIALheaderlinedesignatingthenumberofsoilstratum,themaximumnumberofpointsonanycurveandthesoilIDornamemustinitiatetheTZcurveinput.

    Foreachsoilstrata,thestratalocationlineandtheTZcurvedatafollow.Thestratatopandoptionallythebottomelevationareinputincolumns2530and3136oftheSOILSLOCline.ThenumberofpointsdefiningthecurveandtheTfactorusedtoscaletheforcevalueofallpointsspecifiedaredesignatedincolumns2223and3944,respectively.Ifthecurvehasthesameshapewhetherthepileisintensionorcompression,enterSMincolumns1819.

    TheTandZdataforeachpointonthecurveareenteredontheSOILTZlineimmediatelyfollowingthesoilstratalocationline.Thenumberofdatapointsenteredmustcorrespondtothevaluespecifiedonthestratalocationline.

    Note:Whenusingthesymmetricoption,onlypositivevaluesforTandZmaybeinputandtheorigin,T=0andP=0mustbethefirstdatapoint.

  • 2.4.3.8UserDefinedBearingCapacityCurves

    TZorQZcurvesdefiningthepileendbearingcapacitymaybeinputdirectlybytheuser.TheSOILBEARINGheaderlinedesignatingthenumberofstratumatwhichcapacitycurveswillbedefined,themaximumnumberofpointsonanycurveandthesoilIDornamemustinitiatetheendbearingcurveinput.

    Foreachstratathatbearingcapacityistobedefined,thestratalocationlineandtheTZ/QZcurvedatafollow.Thestratatopandoptionallythebottomelevationareinputincolumns2530and3136oftheSOILSLOCline.ThenumberofpointsdefiningthecurveandtheTfactorusedtoscaletheforcevalueofallpointsspecifiedaredesignatedincolumns2223and3944,respectively.

    TheTandZdataforeachpointonthecurveareenteredontheSOILTZlineimmediatelyfollowingthesoilstratalocationline.Thenumberofdatapointsenteredmustcorrespondtothevaluespecifiedonthestratalocationline.

    Note:Bothpositive(endbearing)andnegative(suction)valuesmaybeentered.Userdefinedendbearingdatashouldnotbedefinedifsoilaxialresistancedataisgeneratedautomatically.

    2.4.5SoilTorsionalResistance

    Torsionalloadsareresistedbyadhesionvalues(skinfriction)alongthelengthofthepileorbyalinearspringvalue.Theresultingshearsactinthecircumferentialdirectionaroundtheperimeterofthepile.Torsionalresistancemustbespecifiedfollowingsoilbearingproperties.Ifthesoiltorsionalresistanceisnotspecified,thetorsionalstiffnessdefaultstoavalueequaltoGJ/L,whereListhelengthofthepile,GisthemodulusofrigidityofthepileatthepileheadandJisthetorsionconstantofthepilecrosssectionatthepilehead.Inaddition,awarningmessageisissued.

    2.4.5.1LinearTorsionalSpring

    Thetorsionalresistancemayberepresentedbyalineartorsionalspringatthepilehead.Thetorsionalspringstiffnessisspecifiedincolumns3140oftheSOILTORSIONHEADline.ThesoilIDornameisspecifiedincolumns4144.

    Note:Whenspecifyingatorsionalspringstiffness,torsionaladhesiondatamaynotbespecified.

    2.4.5.2SoilTorsionAdhesion

    Thepilesoiltorsionaladhesionresistancedatamaybeinputdirectlybytheuser.TheSOILTORSIONHEADlinewiththenumberofstratumandthesoilIDornamedesignatedincolumns1820and4144,respectively,mustbespecified.

    ThedistancefromthepileheadtothetopandthebottomofeachsoilstrataisspecifiedontheSOILSLOCline(s)immediatelyfollowingtheheader.Thetorsionadhesioncapacityatthetopandthebottomofeachstratadefined,isspecifiedontheSOILlineimmediatelyfollowingthestratalocationline.

    2.4.6SoilLateralResistance

    Pileheadlateralloadsareresistedbydistributednormalforcestransversetothepileaxisalongitslength.TheseresistancesmaybespecifiedintermsoftherelationshipbetweenlateralloadanddeflectionrepresentedbyPYcurves.PYcurvescanbegeneratedautomaticallyfrombasicsoilpropertiesorspecifiedbytheuser.

    2.4.6.1GeneratingPYCurvesperAPIRP2A

    PSIcanautomaticallygeneratelateralloaddeflectioncurves(PYcurves)basedonAPIguidelinesfrombasicsoilcharacteristicsinputbytheuser.

    TheSOILLATERALHEADlineisrequiredtogeneratePYcurvesfrombasicsoilcharacteristics.ThenumberofsoilstratatobedefinedandthesoilIDornamemustbespecifiedincolumns1820and4144,respectively.Thereferencepilediameterforwhichthecurvesaregeneratedshouldbeenteredincolumns2833ifthePvaluesofthecurvesaretobemultipliedbytheratioofthepilediametertothereferencediameter.BoththePandYvaluesmaybescaledbytheratioofthepilediametertothereferencediameterbyspecifyingYEXPincolumns2427.

    ThepropertiesofeachstratamakingupthesoilarespecifiedimmediatelyfollowingtheheaderlineusingeitherthesandorclayorsoillateralstratalinedesignatedbySOILAPILATincolumns112.ThestratalocationlabelSLOCincolumns1417isrequired.Theverticaldistancefromthepileheadtothetopofthestrataisspecifiedincolumns2530.Thedistancefromthepileheadtothebottomofthestratamaybeoptionallyinputincolumns3136.Thesoiltypeandthesoilcharacteristicsarerequiredincolumns1922and4568,respectively.

    Foreachstrata,PYdatamaybedesignatedaseitherstaticorcyclicbyspecifyingSorCincolumn23.Forsandstratum,therelativelocationofthewatertableisdesignatedincolumn24.ThePvaluesforaparticularstratamaybefactoredbythenumberinputincolumns3740.Additionally,thePYcurvemaybeshiftedbydesignatingtheamounttobe

  • addedtogeneratedYvaluesincolumns4144.Ahighprecision"P"factorforthisPYcurvecanbespecifiedincolumns7076.

    2.4.6.2UserDefinedPYCurves

    PYcurvesdefiningthesoillateralresistanceforasmanysoilstrataasdesiredmaybeinputdirectlybytheuserasdiscretePYpairsateachsoilstratum.Theonlyrestrictionwhenspecifyingpointsonthecurve,isthatthelateralforceP,mustbeasinglevaluefunctionofthedisplacementY.Shifted,flatandhumpedPYcurvesarepermitted.

    TheSOILLATERALheaderlinedesignatingthenumberofsoilstratum,themaximumnumberofpointsonanycurveandthesoilIDornamemustinitiatethePYcurveinput.

    Thereferencepilediameterforwhichthecurvedataapplies,shouldbeenteredincolumns2833.ThePvaluesofthecurvesaremultipliedbytheratioofthepilediametertothereferencediameter.BoththePandYvaluesmaybescaledbytheratioofthepilediametertothereferencediameterbyspecifyingYEXPincolumns2427.AYfactortobeappliedtoallYvaluesinputmaybespecifiedincolumns3440.

    Note:AlthoughthePYcurvesmaybefactoredbytheratioofthepilediametertothereferencediameter,onlytheoriginalinputcurveisreportedinthelistingfile.

    Foreachsoilstrata,thestratalocationlineandthePYcurvedatafollow.Thestratatopandoptionallythebottomelevationareinputincolumns2530and3136oftheSOILSLOCline.ThenumberofpointsdefiningthecurveandthePfactorusedtoscaletheforcevalueofallpointsspecifiedaredesignatedincolumns2223and3740,respectively.ThePYcurvemaybeshiftedalongthedeflectionaxisbyspecifyingaYshiftvalueincolumns4144.Ifthecurvehasthesameshapewhetherthepileisintensionorcompression,enterSMincolumns1819.Ahighprecision"P"factorforthisPYcurvecanbespecifiedincolumns7076.

    ThePandYdataforeachpointonthecurveareenteredontheSOILPYlineimmediatelyfollowingthesoilstratalocationline.Thenumberofdatapointsenteredmustcorrespondtothevaluespecifiedonthestratalocationline.

    Note:Whenusingthesymmetricoption,onlypositivevaluesforPandYmaybeinputandtheorigin,P=0andY=0mustbethefirstdatapoint.

    Note:Withinasoilstratum,thePSIprogramconnectstheinputPYpointswithstraightlinestofullydefinethepile/soilinteractioncurveforarbitrarydisplacementsinthatstratum.Atdepthsbetweenspecifiedsoilstrata,PSIhastheabilitytolinearlyinterpolatebetweenPYcurvesortouseaconstantPYcurve.

    2.4.7SoilLiquefactionPotential

    SACScancalculatetheliquefactionpotentialofasoillayerforagivenearthquakeloadingandchangethesoilstiffnesspropertiesaccordinglybeforeconductingthepilesoilinteractionanalysis.ThisfunctionalityisavailableinCollapse,PileandPSIprogramsinSACS.

    ForeachsoildefinedinaPSIorPileinputfile,usercanspecifythesoilliquefactiondata.OneSOILLIQUEFYHEADlinefollowedbyanumberofSOILLIQUFYSLOClines,oneforeachstratum,isrequiredtocompletelydescribetheliquefactiondataforthesoil.

    SOILLIQUEFYHEADlinedescription:ThenumberofsoilstratatobedefinedandthesoilIDornamemustbespecifiedincolumns1820and4144,respectively.Seismicloadingmustbespecifiedbyprovidingthevaluesoftheearthquakemagnitudeandthepeakgroundacceleration(asaratioofgravity)incolumns3436and3740,respectively.Thereisalsoanoptiontomaketheestimationofliquefactionpotentialmore(orless)conservativebychangingthevaluesof%horizontalshiftinCRRcurveand%verticalshiftinCRRcurveincolumns2126and2732,respectively.Also,theeffectofliquefactiononsoilstiffnesspropertiescanbemodulatedbychangingtheliquefactionmultiplierfactorincolumns4550.

    SOILLIQUEFYSLOClinedescription:Liquefactionstratalinesshouldfollowtheliquefactionheaderline.Thelocationofthestratumwithrespecttothewatertableshouldbespecifiedincolumn18.Theverticaldistancesfromthepileheadtothetopandthebottomofthestratumarespecifiedarespecifiedincolumns1924and2530,respectively.TheconetipresistancevalueandthesleevefrictionvalueobtainedfromtheCPTtestsarespecifiedincolumns4550and5156,respectively.Submergedunitweightofthesoilisspecifiedincolumns5762.Ifliquefactioneffectsaretobeignoredforastratum,calculationmethodincolumns3133shouldbespecifiedasN.Ifsoiltypeisknown,itcanbespecifiedincolumns3437.

    IfthesoiltypeforaparticularlayerisdescribedasCLAYorifthesoiltypeisnotspecifiedandSACSdetermines(basedontheCPTdata)thatthesoiltypeislikelytobeclay,orifcalculationmethodisspecifiedasN,thenitisassumedthatthislayerisnotpronetoliquefactionandstiffnessvaluesforthislayerarenotchanged.Inallothercases,SACScalculatesthefactorofsafetyforliquefactionduetotheseismicloadingspecifiedbytheuser.Ifthefactorofsafetyiscalculatedtobegreaterthanorequalto1.0,thenthereisnochangeinthesoilstiffness.Ifthefactorofsafetyiscalculatedtobelessthan1.0,thenthelayerisconsideredasliquefiedandafactorcalledliquefactionmultiplieriscalculated.Ifthecalculatedvalueoftheliquefactionmultiplierislessthan1.0,thensoilskinfrictionresistance(Tz),bearingresistance(Qz),andlateralresistance(Py)aremultipliedwithliquefactionmultipliertocalculatethestiffnessoftheliquefiedsoillayer.

    Note1:Liquefactionrelatedcalculationsareconductedatthemiddepthofeachliquefactionstratumspecifiedbytheuser.Therefore,itisadvisabletouseseveralsoilliquefactionstratathroughthepiledepthforabetterestimationoftheliquefactionpotential.

    Note2:liquefactioneffectontheaxialbehaviorisignoredifsoilaxialresistanceisdefinedasadhesionorlinearaxialspringatthepilehead.

    Note3:Both"from"and"to"informationforeachliquefactionstratumisrequired.Thestratashouldbecontinuousandshouldcoveratleasttheentirelengthofthepile.

  • 2.5CREATINGFOUNDATIONSUPERELEMENTS

    UptotwolinearizedfoundationstiffnessmatrixmaybegeneratedateachpileheadtobeusedbytheSACSdynamicsmodulesinlieuofapilestub,pilespringetc.Theprogramcreatesacoupledthreedimensionalstiffnessmatrixforaparticularpilegroupthathaslateralstiffnesspropertiesinbothlateraldirectionsalongwithaxialstiffnessproperties.Thestiffnesspropertiesarederivedfromeithertheaveragedisplacementofallpilesofthepilegrouporthemaximumpiledisplacementsfortheloadcasesdesignatedbytheuser.

    Note:Asuperelementiscreatedforeachpilegroup.Thesuperelementisappliedtoeachpileheadconnectedtoapileassignedtothepilegroupinquestion.

    2.5.1FoundationSuperElementOptions

    LinearizedfoundationsuperelementsorstiffnessmatricesarecreatedateachpileheadautomaticallybythePSIprogramifthePILSUPinputlineisspecified.

    Themethodusedtocalculatedthepilestiffness,AVGorMAX,foraparticularpilegroupisspecifiedincolumns810.Uptofourloadconditions,specifiedincolumns2124,2932,3740and4548,maybechosentocalculatethepilestiffnessintheglobalXdirection.IfdifferentloadcasesaretobeusedtocalculatestiffnessintheglobalYdirection,theymaybespecifiedincolumns2528,3336,4144and4952,respectively.

    AsecondfoundationsuperelementmaybegeneratedbyspecifyingasecondPILSUPline.Inthesamplebelow,thefirstsuperelementistobeusedforFatigueanalysisandiscreatedusingloadcases8and9,whilethesecondsuperelementistobeusedforearthquakeanalysisandiscreatedusingloadcasesDEDXandDEDY.

    Note:StiffnessiscalculatedindependentlyintheXandYdirections.

    2.6SIMULATINGMUDSLIDES

    MudslidesagainstthejacketabovethepileheadcanbemodeledinSeastate.MudslidesagainstthepilesaremodeledinPSIorPileusingflatand/orshiftedPYcurves.InPSI,oneofthepilelocalcoordinatedirectionsisorientedtocorrespondtothedirectionofthemudslidebyspecifyingapilerotationangleonthePILEline.Separatesoiltables(axial,bearing,torsion,lateral)aredefinedforthelocalXYandXZplanesofthepile.

    Note:Normallytheaxial,bearingandtorsionlineswillbethesameforthetwodirectionswithonlythelaterallinesbeingdifferent.

    Inthedirectionofthemudslide,thePYdatacanbethesameasintheotherdirectionexceptthatashiftisspecifiedincolumns4144ontheSOILSLOCline.Conversely,aflatPYcurvethathasconstantvalueofPforallYvalues,maybespecifiedforthemudslidedirection.Ineithercase,forceisexertedbythesoilagainstthepileevenwhenthereisnodisplacement.Thiscorrespondstoanactivesoilexertingathrustonthepileasopposedtotheusualproblemofpassivesoilresistingathrustexertedbythepile.

    IfaninitiallysymmetricalPYcurveisgivenapositiveYshift,asshowninthefigurebelow,thenforanypiledisplacementlessthantheshiftamount,anegativeforceisexertedonthesoil(PYdataisforthesoil,notthepile).Thisinturnresultsinaforceonthepileinapositivedirection.ThustomodelamudslideinthepositiveYdirection(pilecoordinates)apositiveshiftshouldbeused.InthesamemannerifaflatPYcurveisusedtomodelamudslideinthepositiveYdirectionthentheconstantvalueforPmustbenegative.

    ThefigureabovealsoshowsthatforvaluesofYbeyondthelimitsoftheinputdata,theprogramextendsthecurveasflat.Forthisfiguretobevalid,theusermustinputthedirectionforthepilelocalcoordinatessothatthepilelocalYorZaxisisalignedwiththemudslide.ThisisdoneonthePILElineincolumns50to56.

    ThefollowingillustratesshiftedPYdataforsoiltableSOL2.Thecurvesforeachstrataaresymmetricandareshifted7.0and4.25,respectively.

  • Note:Sincethepilelocalcoordinatesaredefinedbythedirectionofthemudslide,ifanysignificantlateralloads(suchaswaves,currentorwind)areactingonthejacketinadirectiondifferentfromthatofthemudslide,theusershouldcheckthefinalpileheadloadsinthePileheadComparisonreporttomakesurethatproperconvergencehasbeenachieved.

    2.7INPUTTINGPILEHEADSTIFFNESSTABLES

    Becausethepile/soilfoundationexhibitsnonlinearbehavior,thepileheadstiffnessmatrixvariesforeachiterationofeachpileforeachloadcase.Normallythiswouldrequirethereformulationofthepilestiffnessmatrixateachiteration,thusrequiringagreatdealofcomputationtime.PSIeliminatesthisrequirementbyinitiallyformingatableofpileheadstiffnesscoefficientsforarangeofvaluesexpectedinthesolution.Thepileheadstiffnessusedforanyiterationisfoundbylinearlyinterpolatingbetweentablecoefficientvalues.Iterationsarecontinueduntilanapproximatesolution(within5percent)isfound.PSIthenproceedsusingafinetuneprocedurewhichrecalculatestheindividualpilestiffnessforeachiteration.

    2.7.1OptionalUserDefinedPileheadStiffnessTables

    Ingeneralnormalconvergenceforpileheadloadsis0.5percent.Forsomesituationshowever,thepileheadstiffnesstablesgeneratedautomaticallybyPSImaynotbeadequatetoobtainthisconvergenceorsufficientprogramaccuracy.Inthesecases,auserspecifiedpileheadstiffnesstablemayberequired.

    Asdiscussedabove,beforetheiterativesolutiontothelateraldeformationproblemsbegins,PSIfirstdoesanumberofpilesolutionsforallcombinationsofuserinputofaxialloadordisplacement,pileheadlateraldisplacement,andpileheadrotation.Theiterativesolutionwillproducevaluesforpileheadaxialload,ordisplacement,lateraldisplacement,androtation.Thesevaluesshouldbewithintherangesspannedbytheuserspecifiedinputvalues.Thisisparticularlyimportantifthefinalvaluesareinahighlynonlinearregionofthecorrespondingloaddeformationsurface.

    Note:Tablerangesforalldegreesoffreedommustbespecifiedifanyareincludedintheinputfile.

    2.7.1.1GuidelinesforAxialRanges

    TheusershouldselecttheinputTABRvaluesbasedonpriorexperiencewithsimilarstructuresandsoilconditionsaswellasPSIanalyses.Thefollowingisofferedasaguide.

    First,thecapacityofthepileincompressionandtensionshouldbefound.IftheaxialsoildataisintermsofTZdata,thecapacitycanbefoundusingthePileprogramwithalargeinputvalueofpileheadaxialdisplacement,largeenoughsothattheZvalueofanypointonthepileisontheflatpartoftheTZcurve.Tenortwentyinchesisusuallysufficient.IftheactualsoildataisexpressedintermsofadhesiondataoriftheAPIsoiloptionisselected,thepilecapacitycanbefoundbyrunningPilewithavalueofaxialloadmuchlargerthanthepilecapacity,inwhichcasetheoutputwillincludeareporttotheeffectthattheappliedloadexceedsthecapacityandthecapacitywillbereported.Avalueof100,000kipsshouldbesufficientinmostcases.

    Aftertheaxialcapacitiesintensionandcompressionarefound,thesevaluesaredividedbyafactorofsafetytogetthemaximumworkingvaluesforaxialload.Thentheintervalbetweenthesetwovaluesissubdividedintoapproximatelyequalsubdivisions,thesetwopointsarethenusedasthevaluesontheaxialTABRlines,thepoint0.0shouldbeamongtheinputvalues.Usuallynomorethanatotalofsevenvalueswillberequired.

    Note:Ifthesoilexhibitshighlynonlinearproperties(suchashumpedTZcurves)andifthepilewillbeoperatingunderconditionsthatplacethedeflectionsalongthelengthofthepileinthehighlynonlinearregion(e.g.pastthehump),thenthepileheadforcedisplacementcurveswillalsobehighlynonlinearandtheaboveguidelinesmaynotbeadequate.MoreTABRvaluesmaybeneededanditmaybenecessarytomakespacingbetweenvaluesmuchclosertogetherforpointswheretheslopeofthecurveischangingrapidlythanfortheregionswheretheslopeischanginglessrapidlysothattheshapesofthepileheadloadvs.

    2.7.1.2GuidelinesforLateralRanges

    NormallyPYsoilpropertiesaresymmetrical,theprincipalexceptionbeingforshiftedPYcurves.TABRvaluesshouldbeenteredforseveralvaluesfromzerotoabout1.5timesthelargestexpectedlateraldeflection.Normallysixorsevenvalueswillbesufficient.IfthePYdataisnotsymmetricalthenseveralvaluesfromabout1.5timesthemaximumexpectednegativedefectionto1.5timesthemaximumexpectedpositivedeflectionshouldbeentered.Thezerodeflectionpointshouldbeoneoftheentries

    Note:Ifthemaximumpileheadlateraldeflectionissmallenoughsuchthatthepileheadlateralloadvs.deflectioncurveisapproximatelylinearforallvaluesofdisplacementuptothemaximumthenmanyfewerthansevenpointsmaybeused.

    Themaximumexpectedlateraldeflectioncanbeestimatedasfollows:NormallySeastatewillhavebeenruntoproducetheloadsonthestructure.Theresultingbaseshearcanbedistributedequallytothepiles,thesepileheadshearswillthenbemultipliedbyafactorofabout1.5togetworkingpileheadshears.ThePileprogramcanberunwiththispileheadshearactinginconjunctionwiththeworkingpileheadaxialload(describedabove).Apileheadrotationalspringhavingstiffnessapproximatingthatofthestructureatthepileheadjointcanbeusedtoaccountfortherestraininginfluenceofthestructureonthepile.ThepileheaddisplacementandrotationcanthenbeusedasthemaximumTABRvalues.TABRvaluesforpileheaddisplacementshouldbeenteredinradiansfromthemaximumnegativetothemaximumpositivevalues.ItisimportantthatbothpositiveandnegativevaluesbeenteredevenifthesoilhassymmetricalPYdatabecausethesignificanceofthesignofthepileheadrotationisthattherotationeitheraugments(positive)thedeflectioncausedbythepileheadshearordiminishesit(negative).Againnormallysevenapproximatelyequallyspacedvalueswillsuffice.InmanycasesthefollowingsetofTABRvaluesforpileheadrotationwillbeadequate:

    Note:Ifthesoilexhibitshighlynonlinearproperties(suchashumpedPYcurves)andifthepilewillbeoperatingunderconditionsthatplacethedeflectionsalongthelengthofthepileinthehighlynonlinearregion(e.g.pastthehump),thenthepileheadforcedisplacementcurveswillalsobehighlynonlinearandtheaboveguidelinesmaynotbeadequate.MoreTABRvaluesmaybeneededanditmaybenecessarytomakespacingbetweenvaluesmuchclosertogetherforpointswheretheslopeofthecurveischangingrapidlythanfortheregionswheretheslopeischanginglessrapidlysothattheshapesofthepileheadloadvs.displacementcurvesareadequatelyapproximatedbythepiecewiselinearcurvesthatareusedtorepresentthem.

    2.7.1.3GuidelinesforTorsionalRanges

    Whiletorsionalloadsonthepileheadsarealmostneververylarge,atorsionTABRlineisalwaysrequired.Thereisnointeractionoftorsionwithanyoftheotherloads(axial,lateral,andbending).Inmostcasestwopoints(e.g.0.0and100.0)willbesufficient.

  • 3.0CREATINGPILEINPUT

    3.1OVERVIEW

    PileandPile3DaresubprogramsofPSIthatcanruninstandalonemodefortheanalysisofapilesubjecttoknownpileheadforcesordisplacements.TheyaremainlyusedtoperformsingleorisolatedpileanalysesandutilizethesameinputfileasthePSIprogramwithminormodifications(seeSection5.2fordetails).PileandPile3DcanbeusedtoplotsoildatapriortoexecutingaPSIanalysis.TheycanalsocreateapostfileforusebytheFatigueprograminordertoevaluatethepilefatiguelife.

    Ingeneral,thePSIinputlinesmaybeusedinthePileorPile3Dinputfiletodescribethepileandsoilmodelexceptwherenotedinthefollowingsections.Thefollowingappliestoexecutionofsinglepileanalysisor3Dsinglepileanalysis,generatingequivalentlinearizedfoundationandpilefatigueusingPileorPile3D.WhenusingPileorPile3Dtogenerateplotsofsoildata,thePSIinputfilemaybeusedwithoutmodification.

    ThedifferencebetweenPileandPile3Disnotedinsubsequentsections.Basically,thedifferenceliesintwoandthreedimensionalpileanalysis.Pile3DoffersanextendedsetofoptionsforsinglepileanalysisoverthatwhichissupportedbyPile.OptionssupportedonlybyPile3Daremarkedassuchinthetext.

    3.2DEFININGANALYSISOPTIONS

    ThePileprogramrequirestheuseofthePLOPTlinetodesignateanalysisoptions.

    Theinputandoutputunitsarespecifiedincolumns78and1112,respectively.Thenumberofpileincrements,themaximumnumberofiterationsandthelateraldeflectionconvergencetolerancearedesignatedincolumns1315,1820and2130,respectively.Thepileunitweightmaybedesignatedincolumns3140.

    Thesoildataplotsand/orsoilreactionsmaybeoutputbyspecifyingPTincolumns4344and6162,respectively.

    ThefollowingshowsaPLOPTlinedesignatingEnglishunits,thelatestAPIcodeand490.materialweight.

    ThecouplingofaxialandtorsionalloadingonapilemaybeachievedusingthecurrentPLOPTlinewiththePile3Dprogram.TheoptionisinputasTTZincolumns4547ofthePLOPTline.Withthisoptionchosenanytorsionalsoildatawillberemovedfromtheinputdatafile.Thisdatawillbecomputedinternally.ThisoptionwiththePile3Dloadingfeaturesisparticularlyusefulforcaissonlikestructureswithfoundationswhicharetorsionsensitive.

    Aspecificationofaxialandtorsionalloadcouplingisshown.TheexamplespecifiesAPIWSD20theditionunitycheckswithEnglishinputandoutputunits.Tenpilelengthincrementsareusedforthefinitedifferencesolution.Pileselfweightisincludedintheanalysiswithpiledensityof490.0lb/ft.Aninputechoistobeprinted,allTZplotswillbeproducedononeplot,andaxialandtorsionalloadsaretobecoupled,withsoilreactionsreportedalongeachstationofthepile.

    3.3SPECIFYINGPLOTOPTIONS

    AsinPSI,plotoptionsaredesignatedonthePLTRQ,PLTLCandPLTSZinputlines.Inaddition,sincethePileprogramonlyallowsonepiletobedefined,thePLTPLinputlinethatallowsspecificationofwhichpilestoplot,isnotapplicable.

    3.3.1PlotData

    DatatobeplottedisdesignatedonthePLTRQinputline.Soilinputdata,axialdeflection,axialload,axialsoilreactions,requiredpilethicknessandunitycheckratiomaybeplottedversuspilepenetration.Lateraldeflection,lateralrotation,bendingmoment,shearloadandlateralsoilreactionalongoraboutthepilelocalYandlocalZaxesmaybeplottedversuspenetrationinadditiontotheresultant.

    Bydefault,foranyoftheresultplotoptions,loadcasestoplotmaybedesignatedonthePLTLCline.Plotappearanceoptionssuchasgridlinesandcrosshatchingmaybedesignatedalso.

    Thefollowingrequestssoildataplots,lateralandaxialdisplacementalongwithunitycheckplots:

    Note:EnvelopeoptionsonthePLTRQlinearenotavailableinthePileprogram

    3.3.2DesignatingLoadCasestoPlot

    Bydefault,allloadcasesareincludedforplotgeneration.IfloadcasesarespecifiedonthePLTLCinputline,thenonlyloadcasesspecifiedwillbeincludedforplottingpurposes.

    3.3.3OverridingPlotSize

    Thedefaultplotpapersize,charactersize,crosshatchingspacingandnumberofcolorsmaybeoverriddenusingthePLTSZline.

  • 3.3.4PlottingSoilDatafromPSIInput

    ThePileprogrammaybeusedtoplotsoildatasothatitmaybecheckedpriortoPSIexecution.WhenusingthePileprogramtogenerateplotsofthesoildata,thePSIinputfilemaybeusedwithoutmodification.

    3.4DEFININGTHEPILE

    Ingeneral,thepileisdefinedusingthesameinputasrequiredbythePSIprogram.Exceptionsarenotedinthefollowingsections.

    3.4.1PileSectionProperties

    SectionpropertiesaredefinedusingthePLSECTandPLGRUPlinesusedinthePSIinputfile.

    3.4.2PileGroupProperties

    Pilegrouppropertiessuchasmodulusofelasticity,shearmodulus,andyieldstressarespecifiedontheappropriatePLGRUPlineasinPSI.

    3.4.3DefiningPileElements

    PileelementsarespecifiedonPILElinesfollowingthePILEheaderinputline.Thepileelementisnamedbytheoptionalpileheadjointnamespecifiedincolumns710.Thepilegrouptowhichthepileisassignedisspecifiedincolumns1618.

    ThesoilIDdefiningpile/soilinteractionpropertiesinthelocalXZplaneisdesignatedincolumns6972.

    Note:BecausethePileisatwodimensionalanalysis,onlysoiltablefortheXZplaneisrequired.

    ThefollowingdefinesapileassignedtopilegroupPL1andusessoiltableSOL1.Apileheadjointwasdesignatedforreferencepurposes.

    PileBatter

    ThepilebattermustbedefinedbybatterdefinitioncoordinatesspecifiedonthePILEline.TheglobalX,YandZdistancesfromthepileheadtoanypointaboveitlyingonthepileaxisshouldbeinputincolumns2130,3140and4150,respectively.Forexample,thefollowingdefinesapilebattered1:8intheglobalXZplaneandverticalintheglobalYZplane.

    Note:Pilebattercoordinatesmaybespecifiedregardlessofwhethertherisevalueofthebatteristhesameforbothplanes.Forexample,apilebattered1:8intheglobalXZplaneas1:10intheglobalXYplanemaybedefinedusingtheX,YandZbattercoordinatesof10.0,8.0and80.0.

    PileHeadHeight

    WiththePile3Dprogram,thepileheadheightrelativetothemudlinemaybeadjustedwiththePILEline.Pileheadheightisspecifiedincolumns5764ofthisline,withpositiveheightslyingabovemudlineandnegativeheightslyingbelowmudline.PilesegmentlengthsandpileheadloadsspecifiedonthePLOD3Dlinearebaseduponthispileheadheight.

    ThefollowingsamplespecifiesapilebatterintheglobalXZplaneof1:10andverticalintheglobalYZplane.Thepileheadlies10.0unitsabovethemudline.ThepilegroupisPL1andthesoiltableisSOL1.

    3.4.4PileLocalCoordinateSystem

    ThepilelocalcoordinatesystemusedinthePileprogramisdefinedasfollows:

    ThepilelocalXaxisextendsfromthepileheaddownthepilealongthepilecenterline.ThelocalZaxisisperpendiculartothepilelocalXaxisandisassumedtobedirectedtotherightofthepile.Usingtherighthandrule,thelocalYaxisisnormaltothepileandpointsintothepage.

    PositiveaxialdeflectionisassumedtobedeflectiondownalongthepileaxiswhilepositivelateraldeflectionisalongthepositiveZaxis.PositiverotationisassumedabouttheYaxisandisintothepaperusingtherighthandrule.

  • ThePileprogramreportspileinternalloadingsuchthatpositiveinternalaxialloadistensionandapositiveinternalZshearloadactsalongthelocalZaxis.ApositiveinternalYmomentactsaboutthelocalYaxisandresultsinacompressivestressontherightsideofthepile.Internalstressesarereportedsuchthatapositiveaxialstressistensileandpositiveshearstressresultsfromapositiveshearload.PositivebendingstresscorrespondstoapositivemomentaboutthelocalYaxis.

    3.4.5PileheadSpring

    UnlikePSI,thePileprogramdoesnotincludetheeffectsofthestiffnessofthestructureconnectedabovethepilehead.Bydefaultthetopofthepileisassumedtobefreetorotateandtranslate.

    However,thestiffnesseffectsofastructureconnectedatthetopofthepilemaybeincorporatedbyspecifyingelasticboundaryconditionsatthetopofthepileusingthePLSPRGline.Alateraland/orrotational(bending)springmaybedefinedbyspecifyingthespringtypeandthespringconstant.Thefollowingdefinesalateralandarotationalspring:

    3.5MODELINGSOILPROPERTIES

    3.5.1Overview

    Ingeneral,soilresistanceisdescribedusingthelinesavailableforuseinPSIinputexceptwherenotedinthefollowingsections.

    3.5.2SoilAxialResistance

    TheaxialcapacityofthesoilmaybedescribedusingthesameinputlinesavailableinthePSIprogram.

    3.5.2.1InputtingAxialLoadDistribution

    Ifaxialsoildatainunavailable,theusermayinputtheaxialloaddistributioninthepileusingtheAXLOADline,thusallowingPiletobypasstheaxialsolution.

    Thenumberofpointsalongthepilethataxialloadwillbespecifiedisdesignatedincolumns1416.Foreachofthesepoints,theaxialforceandthedistancefromthepileheadmustbespecified.Pileusestheseinputvaluesinperformingthelateralsolution.Thefollowingdefinestheaxialloadinthepileateightpoints:

    Note:Compressiveforceshouldbeenteredaspositivevalues.Thefirstvalueenteredshouldbetheaxialloadatthepilehead(0.0incolumns2429).Thisvalueisusedastheaxialloadinthepile.AnyadditionalaxialloadspecifiedusingPLLOADlinesisignored.

    3.5.3SoilTorsionalResistance

    TorsionalresistanceofthesoilisnotconsideredbythePileprogram.AnySOILTORSIONinputlinesareignored.

    3.5.4SoilLateralResistance

    SoillateralcapacityismodeledusingthesametechniquesasthePSIprogrammodule.

    3.5.5SoilLiquefactionPotential

  • SoilliquefactionpotentialiscalculatedusingthesametechniquesasthePSIprogrammodule.

    3.6INPUTTINGPILEHEADSTIFFNESSTABLES

    Pileheadstiffnesstabledataisnotrequired.AnypileheadstiffnessdatainputisignoredbythePileprogram.

    3.7SPECIFYINGLOADINGFORISOLATEDPILEANALYSIS

    Theloadingatthetopofthepilemustbedescribedwhenexecutinganisolatedpileanalysis.Ifcodecheckistoperformed,thecodemustbedesignatedincolumns910onthePLOPTline.

    TheloadingordisplacementsforwhichtoanalyzethepilearedesignatedonthePLLOADline(s).Thelateralforceordisplacementisinputincolumns2130,whilemomentorrotationisinputincolumns3140.Eitheraxialforceoraxialdisplacementbutnotboth,mustbespecifiedincolumns4150or5160,respectively.

    Note:Enterpositiveaxialloadforcompressionorpositiveaxialdisplacementfordisplacementdownalongthepile.

    Theallowablestressmodifierormaterialfactormaybespecifiedincolumns7175.

    AsmanyPLLOADlinesasdesiredmaybeinput.Bydefault,eachPLLOADlineisconsideredtobeaseparateloadconditionunlesstheStartfromprevioussolutionflagisset.Ifthisflagisset,theloadingspecifiedpriortothepresentPLLOADlineisassumedtobetheinitialpositionforthepresentanalysistobegin.Thefollowingdesignatespileloadingwiththesecondlinecontinuingfromtheprevioussolution:

    Note:WhenthePileprogramisrunusingaPSIinputfile(withthePSIOPTlinereplacedbyaPLOPTline),apileanalysiswillbeperformedoneachpileforeachpileloadcase,evenifallpilesareidenticalandareinstalledinthesamesoil.Toavoidthisduplication,itissuggestedthatredundantPILElinesberemovedfromthePileinputfile.

    3.7.13DPileHeadLoad

    ThefirststepincreatingthreedimensionalpileheadloadinginPile3DisspecifyingthepileheadheightonthePILEline.Afterspecifyingthepileheadheight,loadingisappliedtothepileviathePLOD3Dline.Threedimensionalloads(forcesandmoments)orthreedimensionaldisplacements(translationandrotation)maybeappliedtothepileattheheightspecifiedinthepreviousPILEline.ForcesFordisplacementsDarespecifiedincolumns1134momentsMorrotationsRarespecifiedincolumns3558.AllquantitiesspecifiedonthePLOD3Dlinearespecifiedinthepilelocalcoordinatesystem.

    Thefollowingsamplespecifiespileforcesof100.0intheaxialdirection,8.0inthelocalYdirectionandatorsionalmomentof10.0.Thepileitselfhasabatterof1:10intheglobalXZplaneandapileheadheightof10.0.Allforces/momentsareappliedatthisheightabovethemudline.

    3.7.2SpecifyingPileLoadAtDepth

    Anewfeatureofthreedimensionalsinglepileanalysisistheabilitytospecifypileloadingatplacesalongthepileotherthanthepilehead.ThisfeatureiscontainedinthelineDEPLOD.Loads(forcesandmoments)arespecifiedatagivenverticaldepthrelativetothemudline.Verticaldepthisspecifiedincolumns814.Forcesarespecifiedincolumns1636withmomentsspecifiedincolumns3757.EachDEPLODlinecreatesasinglepileanalysis.AllquantitiesspecifiedontheDEPLODlinearespecifiedintheglobalcoordinatesystem.Assuch,inordertoeffectivelyusetheDEPLODlinethemodelmusthavethepositiveglobalZaxisintheverticalupwarddirection.

    Thefollowingsamplespecifiesglobalpileforcesof8.0intheglobalXdirection,0.0intheglobalYdirection,and100.0intheglobalZdirection.Globalpilemomentsof0.0abouttheglobalX,0.0abouttheglobalY,and10.0abouttheglobalZarespecified.Thepileloadingisspecifiedat10.0unitsbelowthemudline.

    3.8CREATINGAPILEFATIGUESOLUTIONFILE

    ThePileprogramcanbeusedtocreateapilesolutionfileforusebysubsequentfatigueanalysis.TheSCFoptionshouldbespecifiedonthePLOPTlineincolumns6365.

    TheforcesandmomentstobeappliedtothepilearedesignatedontheLOADinputline.TheforcesalongX,YandZaxesareenteredincolumns1723,2430and3137,respectivelyalongwiththemomentsabouttheX,YandZaxesspecifiedincolumns3844,4652and5359,respectively.

    Bydefault,theloadsspecifiedareassumedtobeinthepilelocalcoordinatesystem(shownonright).Ifontheotherhand,thepileloadsweretakendirectlyfromamemberinternalloadsreportorarespecifiedusingtheTimoshenkosignconvention,MEMBandINTLmustbespecifiedincolumns6164and6669,respectively.

  • AsmanyLOADlinesasrequiredmaybespecified.Aloadcondition,withresults,willbecreatedinthesolutionforeachLOADlinespecified.

    3.9CREATINGAPILESTUB

    Itisoftendesirableornecessarytoreplacethenonlinearpilesoilsystemwithanapproximatelyequivalentlinearpilestubbeamelement.Staticanalysisofthelinearizedsystemforinstance,maybesufficientlyaccurateforpreliminarydesignpurposes.Fordynamicanalysis,itisnecessarytolinearizethefoundation.

    ThePileprogramoffersanautomatedequivalentpilestubdesignfacilityinwhichtheprogramcalculatesanequivalentpilestubandoutputsinputlinescontainingthepilestubpropertiesincludingmemberlength,memberoffsetsandprismaticsectionproperties.

    3.9.1PileStubLoading

    TheloadingordisplacementsusedtocalculatetheequivalentlinearizedfoundationelementarespecifiedonthePLSTUBline.ThelateralandbendingstiffnessmaybedeterminedusingforcesandmomentsordisplacementandrotationbyenteringForDincolumn10,respectively.Ifdeflectionsaredesignated,thelateraldeflectionandrotationareenteredincolumns2130and3140.Otherwise,lateralshearforceandmomentshouldbeentered.Eitheranaxialloadoraxialdisplacement,butnotboth,maybespecifiedincolumns4150or5160.

    Note:Theloadsspecifiedatthepileheadshouldbespecifiedinthepilelocalcoordinatesystem.ForamoredetaileddiscussiononthetheoryandderivationoftheequivalentpilestubprocedureusedbyPile,seetheCommentary.Sampleproblem2illustratestheprocedureindetail.

    3.10CREATINGALOAD/DEFLECTIONCURVEFORSOILS

    ThePileprogramcanbeusedtocreatetheloadversusdeflectioncurvesforagivenpilehead.Thisisusefulforthevisualizationofspecificstaticload/deflectioncharacteristicsinthespecifiedpilehead.Pileheadcapacitymayoftenbeeasilydeterminedbyexaminingthepeakofthepileheadload/deflectioncurve.

    Thecreationofaload/deflectioncurveisaccomplishedbymeansoftheLODFLline.Thislineisusedtocalculatetheaxialcompressionandtensionpileheadversusdeflection.Thenumberofdeflectionincrementsisenteredincolumns710.Themaximumaxialdeflectionisenteredincolumns1120.Thedeflectionrangefromzerotothemaximumaxialdeflectionisdividedevenlybythenumberofdeflectionincrements.Apileheadloadiscalculatedforeachaxialdeflection.IftheunitsspecifiedwereSI,thefollowinglinedefinesaload/deflectioncurvewithfiftypointsandamaximumaxialdeflectionof15.0centimeters.

    Note:theLODFLlineisonlyusedinsinglepileanalysis.

    Usingtheaboveloaddeflectionline,thepileprogramwillproduceaneutralpicturefilewiththeload/deflectioncurveplottedwiththegivennumberofpointsandmaximumaxialdeflection.Anexampleoftheoutputproducedisshown.TheLODFLoptionsusedtocreatethefigurewerethoseshownaboveintheexampleline.

  • 4.0COMMENTARY

    4.1INTRODUCTION

    PSI,(PileStructureInteraction),analyzesthebehaviorofapilesupportedstructuresubjecttooneormorestaticloadconditions.Finitedeflectionofthepileisaccountedfor(thePdeltaeffect)andthesoilmayexhibitnonlinearforcedeformationbehaviorbothalongandtransversetothepileaxis.

    Becauseofthenonlinearbehaviorofthepilesoilsystem,theoverallstiffnessofthestructurefoundationsystemisafunctionofdisplacement.Inalinearanalysisthestructuralstiffnessmatrixisformedbasedontheundeformedstructureanddoesnotchangeasthestructuredeforms.Whenthereissignificantnonlinearity,however,thestiffnessmatrixforthedeformedshapecannotbedetermineduntilthedeformedshapeisobtained.Thedeformedshape,inturn,cannotbefounduntilthestiffnessmatrixisfound.

    Iterativemethodshaveproventobeusefulforsolvingproblemsofthistype.Onestartswithaninitialassumptionforthedisplacementsandsolvesforthestiffnessmatrix.Newdisplacementsarefoundusingthisstiffnessmatrix,thenanupdatedstiffnessmatrixisformed.Theprocessisrepeateduntilthecalculateddisplacementsforaniterationarewithinaspecifiedtoleranceofthosefromthepreviousiteration.

    Thetechniquedescribedaboveisnotpracticalforstructureswithmanydegreesoffreedomwithoutfirstintroducingthenotionofcondensationofthestructuralstiffnessmatrix.

    Thestructureisdividedintotwoparts,withtheinterfaceatthepileheadjointsatornearthemudline,asshowninFigure1below.

    Thepilesbelowthepileheadjointsarenonlinearelementswhilethestructureabovethepileheadjointsislinear.Thestructureabovethepileheadjointsservesthefollowingroles:

  • 1. Connectthepilestoeachotherwithamediumhavingcertainwelldefinedlinearstiffnessproperties.2. Introduceloadstothepileheads.

    Theprocessofcondensationinvolvesreducingthelinearstructureabovethepileheadjointsandloadstoanequivalentlinearstiffnessmatrixinvolvingonlythepileheaddegreesoffreedomandasetofforcesappliedtothosedegreesoffreedom.Forexample,afourpilejacketmayhaveseveralhundreddegreesoffreedombutthenonlinearpartofthestiffnessmatrixwillonlyhave24degreesoffreedom(i.e.4pileheadjointswith6degreesoffreedomperpile).

    4.2DERIVATIONOFINTERACTIONEQUATIONS

    Toderivetheinteractionequation,firstconsiderasinglepileasillustratedinthefigurebelow.

    Assumethatthedeflectedshapeofthepileisverynearlyinaplanecontainingtheaxisofthepile.Thisassumptionisvalidif:

    1. Thepileheadtorquedoesnotinfluencethelateraldeflection.2. Theresultantpileheadbendingmomentisaboutanaxisperpendiculartothedirectionoftheresultantpileheadlateralforce.

    Note:Thereasonsforthisassumptionwillbeaddressedlaterinthediscussion.

    Thefirstoftheseconditionsmaybeacceptedbasedontheusualsmalldisplacementrestrictionofstructuralanalysis.Theusualconditionsunderwhichoffshorestructures(andindeedmostotherstructures)operateproduceresultantpileheadbendingmomentsandlateralforcesthatnearlysatisfycondition2.Notethatitisnotassumedthatallofthepilesdeforminthesameplane,butonlythateachpiledeformsinaplane.Thatplane,however,maybedifferentfrompiletopile.

  • Plotscanbedevelopedrelatinganypileheadforce(ormoment)componenttoanypileheaddisplacement(orrotation)componentforfixedvaluesofaxialloadandtheotherdisplacementorrotationcomponents.AtypicalplotmayhavethegeneralappearanceofFigure3.TheslopeofthecurveatapointsuchasA,isdefinedasthestiffnesscoefficientrelatingtheforceormomenttothedisplacementorrotationatthatpointA.Itisafunctionofdisplacement,rotation,oraxialload.

    TheequationoftheFvs.curvemaybewrittenintheform:

    (1)

    whereKandFOarefunctionsof,,andP.Theseconsiderationsaregeneralizedto6pileheaddegreesoffreedomandtheresultswritteninmatrixform:

    (2)

    where{F},{},and{FO}are61matrices(columnvectors)and[K]isa66matrix.Inaddition,[K]and{FO}arefunctionsof,,andP.

    Figure4isaschematicsketchofajacketsupportedbypiles.Thenonlinearpilesaresymbolicallyrepresentedbythespringlikeelementsatthepileheadjoints.Externalforcesareappliedoverthejacketincluding,perhaps,atthepileheadjoints.Thejacketconsistsofthepileinterfacedegreesoffreedom(designatedbysubscriptI)andthefreedegreesoffreedom(designatedbythesubscriptF).TheForceDisplacementrelationshipforthejacketpilecombinationcanbewritteninpartitionedmatrixnotationas:

    (3)

    Inequation3,thetermsFFandFIaretheexternalforcevectorsappliedtothestructureatthefreeandinterfacedegreesoffreedomrespectivelyandDFandDIarethecorrespondingdisplacementvectors.KPistheassemblednonlinearstiffnessmatrixofthepilesattheinterfacedegreesoffreedom,andFOisthecolumnvectorofthepileinterceptforces.Asdiscussedpreviously,bothKPandFOdependontheinterfacedisplacementvectorDI.Allotherstiffnesscoefficientsareindependentofthedisplacementsandcanbeevaluatedonceatthestartoftheproblem.

  • Figure5(above)showsthefreebodiesofthejacketandpiles.Theforcesactinginthesebodiesincludetheequalandoppositeinterfaceforcevector,FI.Theforcedisplacementrelationshipsforthepilesandjacketrespectivelyare:

    (4)

    (5)

    Equations4and5aresimplyabreakdownofequation3intothecontributionfromthenonlinearpileandlinearstructurerespectively.Combiningthesetwoequationsyieldsequation3.Equation5canbeexpanded,resultingin:

    (6)

    (7)

    Equation6issolvedforDFandtheresultissubstitutedintoequation7,whichisthenrearrangedtogive:

    (8)

    Equation8isamatrixequationwhoseorderisequaltothenumberofinterfacedegreesoffreedomofequation4.AddingthesetwoequationseliminatestheinternalinterfacevectorFI.

    (9)

    ThetermsinthisequationcanbegroupedintothosethatdependonDIandthosethatdonot.Theliketermsarecollectedandtheequationarerearrangedresultingin:

    (10)

    where:

    Equations4and10arethebasisfortheiterativesolution.Onecandoananalysisofeachpileusingthecurrentpileheaddisplacementvectorasitsboundarycondition.Thepileheadforceandmomentarecalculated,thenasecondpileanalysisisdonewithanincrementaddedtothedisplacements,resultinginnewforcesandmoments.Thestiffnesscoefficientsthenaretheratiosofeachofthepileheadforce(ormoment)incrementstoeachofthedisplacement(orrotation)increments.Thepileheadinterceptforce(ormoment)componentsarethencalculatedusingequation4.

    Thisprocesscanberepeatedforeachiterationateachpileheadandforeachloadcase.Thisapproach,althoughtheoreticallysound,canrequirealargenumberofpileanalyses.

    ThePSIprogramusesamoreefficientapproach.Insteadofdoingpileanalysesateachpileforeachiterationofeachloadcase,anumberofpileanalysesaredoneattheoutsettoproduceasetofpileheadforcevs.displacementcurvessimilartoFigure3.Valuesforpileheadaxialload(ordeflection),lateraldeflection,androtationthatspantherangeofvaluesexpectedinthefinalsolutionareused.Theprogramperformsapileanalysisforeachcombinationoftheseloadsandrotationsandstorestheresults.Foreachiteration,thepileheaddisplacementsareusedtodeterminetheresultingpileheadstiffnesscoefficientandinterceptforcesfromthecurves.Thisprocedureiscontinueduntilapreliminaryconvergenceismet.Uponconverging,PSIcontinuesiteratingbutnowperformsacompletepilestiffnessanalysisforeachiteration.Thisfinetuningprocedurecontinuesuntiltheforcetoleranceormaximumnumberofiterationsismet.

    4.3ALIGNINGTUBULARPILELOCALCOORDINATES

    ThePYdataforthetypeofproblemscommonlyencounteredintheoffshoreapplicationscanbehighlynonlinearforarangeofdisplacementsoverwhichthepilemayhavetofunction.Thisresultsinpileheadlateralforcedisplacementcurvesthatarelikewisenonlinear.Becauseofthis,inordertogetmoreaccurateresults,PSIperformsitsiterationsintheplaneoftheresultantpileheadlateraldisplacementfortubularpiles.

    Inactuality,thefinalresultsmayhaveasmallcomponentofdisplacementoutoftheanalysisplane.Thisisbecause,foreachpile,theplaneisfoundinthefirstiterationandthatplaneisusedforallfurtheriterations.ThechordangleusedinthefirstiterationisreportedintheInitialDeflectionsreportforeachloadcaseundertheheaderBeta.

  • Toillustratethenecessityfortheapproachtaken,considerapilehavingthepileheadforcedisplacementcurveshowninfigure8(b).Furthermorethepileisloadedinadirectionmakinganangleof45degreeswiththecoordinatesusedforanalysis.ThetrueresultantforceonthepileheadisF,thecorrespondingtrueresultingdisplacementis.ThetrueXandYcomponentsofthepileheadforceareeach0.707(F).Ifthepilewereanalyzedinthesecomponentdirectionsthedisplacementswouldbeequaltoeachotherandhavethevalue0.707,asshowninfigure8(b).Thevectorsumofthesedisplacementswouldbewhichisfarlessthanthetruedisplacement.Thusinordertoinsureanaccurateresultitisseenthattheiterativeanalysisshouldbedoneintheplaneofthepiledeformation.

    Thereforeaccuracyislostifalargecomponentofpileheadbendingmomentexistsinthedirectionoftheresultantpileheadlateralload.Ontheotherhand,ifthiscomponentofmomentissmallthenonlyanegligibleerrorismadebyvectoriallycombiningtheanalysesinthetwoplanes.

    4.4APIRP2APILERESISTANCE

    PSIallowstheusertospecifythepile/soilresponsetoaxial,lateral,andtorsionalloadsappliedatthepilehead.Inlieuofthisinformation,theusermayspecifygeneralsoilpropertieswithwhichthePileprogramwillusetodevelopthepile/soilresponsebasedonAPIRP2Arecommendations.

    4.4.1AxialResistance

    4.4.2UltimatePileCapacity

    Section6.4ofthetwentietheditionofAPIRP2Asuggestthatthepilecapacity,Qd,maybedeterminedfrom:

    (6.41.11)

    wheref=unitskinfrictioncapacity,As=sidesurfaceareaofpile,q=unitendbearingcapacityandAp=grossendareaofpile.

    4.4.3SkinFrictionandEndBearing

    Forpipepilesincohesivesoils,theunitskinfriction,f,atanypointalongthepile,canbecalculatedfromthefollowing:

    wherecistheundrainedshearstrengthandisadimensionlessfactorthatmaybetakenas:

    where=c/po'andpo'istheeffectiveoverburdenpressure.Theunitendbearingqforpilesincohesivesoilsistakenas9*c.

    Forpipepilesincohesionlesssoil,theunitskinfrictionandunitendbearingarecalculatedfrom:

    (6.4.31)

    (6.4.32)

    whereK=coefficientoflateralearthpressure,pO=effectiveoverburdenpressure,=angleofsoilfrictiononpilewallandNq=bearingcapacityfactor.

    Note:Unitskinfrictionandunitendbearingforcohesionlesssoilsdonotincreaselinearlywiththeoverburdenpressureindefinitely.Thevaluesarelimitedtothemaximumvalueslistedinthetablebelow.

  • Theusermayentervaluesfortheseparametersoruseprogramdefaults.Thecoefficientforlateralearthpressure,K,maybebetween0.5and1.0assuggestedbyAPI,andhasadefaultvalueof1.0.Atanydepththeprogramusestheweightofthesoilabovethelevelastheeffectiveoverburdenpressure,PO.Thisweightiscalculatedusingthesubmergedunitweightofthesoil,whichtheusermustinput.Thedefaultvaluesforfrictionangle,,andbearingcapacityfactor,Nq,dependonthesoiltypeandarelistedalongwithfmaxandqmaxbelow:

    SoilType Nq fmax qmaxGravel 350 50 2.4 250

    CleanSand 300 40 2.0 200

    SiltySand 250 20 1.7 100

    SandySilt 200 12 1.4 60

    Silt 150 8 1.0 40

    Note:Forrocktheusermustinputvaluesfortheskinfrictioncapacity,f,andtheunitbearingcapacity,q.

    4.4.4SoilAxialLoadTransferCurves

    Axialloadtransferandpiledisplacementcurves,TZcurves,areconstructedbasedonAPIRP2Arecommendations.TheTZcurvesaregeneratedbasedonthefollowingtableswherezisthelocalpiledeflection,Disthepilediameter,tisthemobilizedsoiladhesionandtmaxisthemaximumsoilpileadhesionorunitskinfriction.

    Clay Sandz/D t/tmax z t/tmax0.00 0.00 0.00 0.00

    0.0016 0.30 0.10 1.000.0031 0.50 1.000.0057 0.75 0.0080 0.90 0.0100 1.0 0.0200 0.700.90 0.700.90

    4.4.5TipLoadDisplacementCurves

    TheendbearingortiploadcapacitycanbegeneratedintheformofendbearingTZ(orQZ)curvesbasedonAPIRP2Arecommendationsasfollows:

    z/D 0.002 0.013 0.042 0.073 0.100 t/tp 0.25 0.50 0.75 0.90 1.00 1.00

    wherezistheaxialtipdeflection,Disthepilediameter,tisthemobilizedendbearingcapacityandtpisthetotalendbearing.

    4.4.6LateralResistanceforSoftClays

    PYcurvesforlateralresistancearegeneratedbasedonthesuggestionsinsection6.8ofthetwentietheditionofRP2A.Forsoftclaystheultimateresistingpressure,pu,isgivenby:

    forXXR

    (6.8.22)

    where:

    c=undrainedshearstrengthofundisturbedclaysampleD=pilediameter=effectiveunitweightofthesoilJ=dimensionlessconstantbetween0.25and0.5X=depthbelowsoilsurfaceXR=depthtobottomofthezoneofreducedresistance.

    Note:XRisthevalueofXforwhichequations6.8.21and6.8.22produceequalvaluesforpu.

    OncetheultimateresistanceisknownthePYcurveisconstructedasaseriesofstraightlines.Twocasesarise:staticandcyclicloadconditions.ForthestaticcasethefollowingpointsdefinethePYcurve:

  • wherep=lateralresistance,y=lateraldeflection,yc=2.5ecDandec=strainatonehalfthemaximumstressforundrainedcompressiontestforundisturbedsamples.

    ForcyclicloadingthepointsdefiningthePYcurvesare:

    4.4.7LateralResistanceforSand

    RP2Agivestheultimatebearingcapacityforsandasthesmallervalueof:

    wherepu=ultimateresistance(subsciptsforshallow,dfordeep),=effectiveunitweightofsoil,H=depth,D=pilediameterandC1,C2,C3=coefficientsfromfigure6.8.61inAPIRP2A(using'=angleofinternalfrictionforsand).

    Theloaddeflection(PY)curvesarenonlinearandareapproximatedbythefollowingexpression:

    wherepu=ultimatebearingcapacityatdepthH,k=initialmodulusofsubgradereaction,y=lateraldeflection,H=depth,A=0.9forcyclicloadingor3.00.8H/D0.9forstaticloading.

    4.5EQUIVALENTPILESTUB

    Thefollowingisthederivationofthemethodusedtolinearizethesoil/pilesystemintoanequivalentpilestub.

    Throughoutthisdiscussion,thefollowingdefinitionsapply:

  • RigidLinkRelationships:

    GoverningEquationsMatrixNotation

    ElasticStub

    RigidLink

    (B2)

    (B3)

    or

    (B3')

    Substituting3'into1theninto2thefollowingequationresults.

    (B4)

    (CombinedStiffness)Theelasticstubstiffnessmatrixcanberewrittenasfollowsfrombeamtheory.

  • Invertingthematrixyields:

    therefore,fortheelasticstub:

    (B5)

    (B6)

    (B7)

    Substitutethesevaluesintoequation4todeterminecombinedstiffnessterms.

    SolvingforI,LoandLyields:

    (B8)

    (B9)

    (B10)

    Inaddition,theaxialstiffnessofthepileismodeledbygivingthepileacrosssectionalareasuchthat:

    or

  • wherethelength,L,isfromequation(B10).

    4.5.1RulesforModelingaPileStub

    Pilestubsmaybemodeledsuchthatthestubrunsdownfromthepileheadtothepilestubtiporfromthepilestubtipuptothepileheadjoint.Ineithercase,thedistancefromthepileheadtothepiletipisrepresentedbyL+Lo,whereListheactuallengthofthepilestubelementandLoiseitherapositiveornegativeoffset.

    ThePileprogramreportsthepilestubpropertiesassumingthatthepilestubismodeledfromthepileheaddowntothepilestubtip.Therefore,positiveoffsetsreportedbytheprogramrefertoanoffsetdownfromthepileheadjointthatshortensthestubmember(seeFigureA).Conversely,offsetsreportedasnegativenumberselongatethepilestubabovethepileheadjoint(seeFigureB).

    Whenaddingpilestubstoamodel,thefollowingrulesshouldbeadheredto:

    1. UsePrismaticcrosssectionPRIfortheelasticstubmodel.Useshearareastentimeslargerthantheaxialareatoeliminatesheardeflection.

    2. Uselocalmemberoffsets.

    3. Fixthetipofthepilestubtoground.

    5.0TROUBLESHOOTINGCOMMONPROBLEMS

    PSIisaniterativesolutionapproachtoahighlycomplicatedproblemandassuchrequiresacertaindegreeofcareonthepartoftheuser.ThefollowingsectiondiscussesmeansofavoidingandcorrectingproblemsthatmayariseduringexecutionofPSI.

    1. Whenapilecannotcompletelydissipatetheaxialload,itmayexperiencesoilpunchthrough.Usuallypilesexhibitingthisproblemmustberedesignedwithincreasedpilepenetration,thusprovidingmorepilelengthavailabletodissipatetheload

    ThisproblemmayalsooccurifuserspecifiedTABRvaluesexceedthepilesaxialcapacity.Ifthefinalaxialloadsaremuchsmallerthantheuserinputvalues,thevaluesshouldbedecreasedsothattheaxialbehaviorisadequatelydefinedintherangeofthesolutionvalueandtheuserspecifiedloadsdonotcausepunchthrough.Alternatively,theusercanspecifyaxialdeflectionvaluesinsteadofloadvalues.

    2. Theiterativepilesolution(eitheraxialorlateral)mayfailtoconverge.Theprogramwillproduceamessagetotheeffectthatthesolutiondidnotconvergefortheparticularsetofconditionsinvolved.

    ThisusuallyoccursfortheaxialsolutionwhentheTZcurveshaveasharpslopediscontinuityforthesamevalueofdisplacementoverthelengthofthepile.Iftheaxialloadissuchthatthepiledisplacesbythisamount,theiterationproceduremaycyclebackandforthfromoneportionoftheTZcurvetoanotherwithoutconverging.TheproblemcanbecorrectedbyeitherreplacingtheTZcurvesbyoneswithamoregradualtransitionfromoneportiontoanotherorbychangingtheTABRvalue(ifspecified)byasmallamount(perhaps5or10percent)sothatthepilesolutionwillberemovedfromthepointofslopediscontinuity.Similarbehaviormayoccurforthelateralsolution,butislesscommonsinceforlateralloadstheentirepiledoesnotdisplacebyapproximatelythesameamountasisthecaseforaxialloads.LackofconvergenceforlateralloadsmaybesimilarlycorrectedbymodifyingthePYcurvestosmoothouttheslopediscontinuitiesorbychangingtheoptionallateralTABRdeflectionvalues.

    3. Thenumberofiterationsallowedperloadcasemaybeexceededif:

    a.toofewiterationsarerequested(columns4143ofthePSIoptionsline).b.theconvergencetolerancesaretoosmall(columns2540ofthePSIoptionsline).c.unusualsoilconditions,suchasaverystiffstratum(rock)sandwichedbetweentwoverysoftstrata,arepresent.

    Theproblemcanusuallyberesolvedbyincreasingthenumberofiterations.

    4. Thecombinedreducedstructuralstiffnessmatrixandpileheadstiffnessmatrixisnonpositivedefinite.Thecombinedstructuralandpilestiffnessmatrixmaybesingular.Thisisusuallytheresultofajointinthestructurebeingimproperlyconstrained.Oneverycommoninstanceofthisiswhenaconductorisreleasedforallthreerotationsatallofitsnodes,includingthetopone.Thiscausestheconductortohavenotorsionalstiffness,whichresultsinthesingularstiffnessmatrix.ThecorrectionistoremovethereleaseforrotationaboutthelocalXaxisatanynodeornodes.

    6.0SAMPLEPROBLEMS

    ThestructureshowninthefigurewasusedtoillustratethevariouscapabilitiesofthePSIprogram.Threeseparaterunsareillustrated:

    1. ThefirstproblemisatypicalPSIanalysiswhereaxialandlateralsoilpropertiesaredescribedbyTZandPYcurvesrespectively.Inaddition,numerousplotsweregeneratedincludingthesoildata,axialandlateraldeflectionsandpileunitycheck.ThepileheadstiffnesstablesweregeneratedautomaticallyinPSI.

    2. SampleProblem2isasinglepileanalysisusedtodeterminetheequivalentpilestubofthesoil/pilefoundation.Inlieuofcurvestodefinethesoilloaddisplacementrelationships,generalsoilpropertieswereinput.PileusedthisinformationtoformthesoilloaddisplacementrelationshipperAPIRP2Arecommendations.

  • 3. SampleProblem3illustratesamudslidecaseintheglobalXdirection.Userdefinedpileheadstiffnesstableswereused.

    SAMPLEPROBLEM1

    ThefollowingisanexampleofatypicalPSIanalysiswhereTZandPYcurvesareusedtodefinetheloaddisplacementrelationshipofthesoil/pilefoundationintheaxialandlateraldirectionsrespectively.

    Thestructureshowninthefigurestandsin82.02ft.ofwater.Themodelcontainsoneuserdefinedloadcondition(LC1),whichrepresentsa150psfliveloadonthedeck.Loadconditions2and3containenvironmentalloadingincludingwind,wave,currentandgravity.Windarea,marinegrowth,coefficientofdragandmassoverrides,andmemberandgroupoverridesarespecified.Loadconditions4and5arecombinationsofloadcases1and2,and1and3respectively.Onlytheloadcombinations(LC4andLC5)arepassedtoPSIforanalysis.

    ThefollowingisaportionoftheSACSinputfilecontainingtheinputlines.Forclarity,somemodeldatanotspecifictoPSIhasbeenomitted.Themodelinputfilespecifiesthefollowing:

    A. TheOPTIONSlinespecifiesaPSIanalysis(col.1920)withnocodecheckforthemainstructure(col.2526).B. TheLCSELlinespecifiesthatonlyloadcases4and5aretobepassedtoPSIforanalysis.C. Joints2,4,6and8arespecifiedaspileheadjointsbyPILEHDincolumns5560ontheJOINTline.

  • ThefollowingisthePSIinputfileusedinSampleProblem1,followedbyadetaileddiscussionoftheinputlines.

  • A. ThePSIOPTlinespecifiesEnglishunits(col.1012)andthatafinalpileanalysisistoexecutedwithsummarizedoutputreports.

    B. ThePLTRQlinerequestthatsoildata,axialdeflection,lateraldeflectionandunitycheckplotsbegenerated.

    C. ThePLGRUPlinesdesignatepilegroupPL1asa28inchdiametersegmentedmember1.5inchwalland50ksi,forthefirst50feetand0.75inchwall36ksifortheremaining175feet.

    D. Pileheadjoints2,4,6and8areassignedreferencejoints201,203,205and207respectively.AllpileshavememberpropertiesdefinedbygroupPL1andusesoilpropertiesdefinedbysoilgroupSOL1.

    E. TheSOILTZAXIALHEADlineindicatesthattwosoillayerswillbedefinedbyTZcurvesforsoilgroupSOL1.

    F. Theelevationofthesoillayer,thenumberofpointsdefiningthecurveforthatlayerandthefactortowhichmultiplyTby,aredesignatedontheSOILSLOCline.

    G. TheTZcurveforthesoillayerspecified,isdefinedbythepointsspecifiedontheSOILTZline.

    H. Atorsionalspringwithstiffnessvalueof277910.0inkip/radianforsoilgroupSOL1isdesignatedontheSOILTORSIONHEADline.

    I. TheSOILLATERALHEADlinespecifiesthatfivesoilstrata,withamaximumof13pointsdefiningthePYcurve,willbeusedtodefinethelateralloaddeflectionrelationshipofthesoil/pilesystem.Thereferencediameteris28.0inches.

    J. ThePYcurveforthesoillayerattheelevationspecifiedonthepreviousSLOCline,isdefinedbythepointsspecifiedontheSOILPYline.

    ThefollowingarethePSIoutputplotsandaportionofthelistingfileforSampleProblem1.

  • SAMPLEPROBLEM2

    SampleProblem2isasinglepileanalysisusedtodeterminetheequivalentpilestubofthesoil/pilefoundation.Inlieuofcurvestodefinethesoilloaddisplacementrelationships,generalsoilpropertieswereinput.PileusedthisinformationtoformthesoilloaddisplacementrelationshipperAPIRP2Arecommendations.

    Thefollowingistheinputfileusedfortheequivalentpilestubanalysisalongwithadescriptionoftheinputlines:

  • A. ThePILOPTlinespecifiesEnglishunits(col.1012)andthatapilecodecheckistoexecuted.

    B. ThePLTRQlinerequestthatsoildataplotsbegenerated.

    C. ThePLGRUPlinesdesignatepilegroupPL1asa28inchdiametersegmentedmember1.5inchwalland50ksi,forthefirst50feetand0.75inchwall36ksifortheremaining175feet.

    D. Pileheadjoint2isassignedmemberpropertiesdefinedbygroupPL1andusesoilpropertiesdefinedbysoilgroupSOL1forthepilelocalXZandXYplanes.

    E. TheSOILAXIALHEADlineindicatesthatthesoilaxialpropertieswillbedescribedforeightsoilstrata.TheprogramwillgenerateskinfrictionandbearingbasedonAPIRP2Arecommendations.ThesesoilpropertiesareassignedtosoilgroupSOL1.

    F. Theelevationofeachsoillayer,thetypeofsoilandthecharacteristicsofthesoillayerarespecifiedontheSOILAPIAXLSLOCline.

    G. Atorsionalspringwithstiffnessvalueof1000.0inkip/radianforsoilgroupSOL1isdesignatedontheSOILTORSIONHEADline.

    H. TheSOILLATERALHEADlinespecifiesthatsixsoilstratawillbeusedtodefinethelateralloaddeflectionrelationshipofthesoil/pilesystem.Thepilereferencediameteris28.0inches.

    I. TheSOILAPILATSLOClinesspecifythesoilpropertiestobeusedtodevelopPYcurvesbasedonAPIRP2Arecommendations.Thesoiltype,elevationandsoilpropertiesforeachsoillayerarespecified.

    J. ThePLSTUBinputlinedesignatestheloadsordeformationsthataretobeusedtodetermineanequivalentpilestub.Inthissample,theDincolumn10designatesthatpileheaddisplacementswillbeinput.Areferencejointname1002incolumns11to14isdesignatedandalateraldisplacementof2.2802inchesandarotationof0.01306radiansarespecified.Thecorrespondingaxialloadof625.4isalsospecified.

    ThefollowingistheneutralpicturefileandaportionofthePileoutputlistingforSampleProblem2.

  • SAMPLEPROBLEM3

    SampleProblem3isthesameasSampleProblem1exceptthatamudslideintheglobalXdirectionwasisspecifiedinthePYdata.Also,userdefinedpileheadstiffnesstablesarespecifiedintheinputfile.ThefollowingisthePSIinputfile,followedbyadescriptionofthelines.

  • A. ThePSIOPTlinespecifiesEnglishunits(col.1012)andthatafinalpileanalysisistoexecutedwithsummarizedoutputreports.Theweightofthepileistobeincluded,andcalculatedusingadensityof490lbs/cu.ft.

    B. ThePLTRQlinerequestthatsoildata,lateraldeflectionandunitycheckplotsbegenerated.

    C. ThePLGRUPlinesdesignatepilegroupPL1asa28inchdiametersegmentedmember1.5inchwalland50ksi,forthefirst50feetand0.75inchwall36ksifortheremaining175feet.

    D. Pileheadjoints2,4,6and8areassignedreferencejoints201,203,205and207respectively.AllpileshavememberpropertiesdefinedbygroupPL1andusesoilpropertiesinthelocalXZandXYplanesdefinedbysoilgroupsSOL1andSOL2respectively.Also,pilechordanglesof225,135,45and315degreesforpileheadjoints2,4,6,and8respectively,havebeenassignedinordertoalignthepileXYplanewiththeglobalXZplane.

    E. TheSOILTZAXIALHEADlineindicatesthattwosoillayerswillbedefinedbyTZcurvesforsoilgroupSOL1.

    F. Theelevationofthesoillayer,thenumberofpointsdefiningthecurveforthatlayerandthefactortowhichmultiplyTby,aredesignatedontheSOILSLOCline.

    G. TheTZcurveforthesoillayerspecified,isdefinedbythepointsspecifiedontheSOILTZline.

  • H. Atorsionalspringwithstiffnessvalueof277910.0inkip/radianforsoilgroupSOL1isdesignatedontheSOILTORSIONHEADline.

    I. TheSOILLATERALHEADlinespecifiesthatfivesoilstrata,withamaximumof13pointsdefiningthePYcurve,willbeusedtodefinethelateralloaddeflectionrelationshipofthesoil/pilesystem.Thereferencediameteris28.0inches.

    J. ThePYcurveforthesoillayerattheelevationspecifiedonthepreviousSLOCline,isdefinedbythepointsspecifiedontheSOILPYline.

    K. ThesecondSOILTZAXIALHEADlineindicatesthattwosoillayerswillbedefinedbyTZcurvesforsoilgroupSOL2.TheprocedureforTZcurvesforSOL2isthesameusedforSOL1.

    L. TheSOILLATERALHEADlinespecifiesthattwosoilstrata,willbeusedtodefinethemudslidelateralloaddeflectionrelationshipofthesoil/pilesystem.Thereferencediameteris28.0inches.

    M. ThePYcurveforthesoillayerattheelevationspecifiedonthepreviousSLOCline,isdefinedbythepointsspecifiedontheSOILPYline.

    N. Thepileheadstiffnesstablesforaxialdeflection,lateraldeflection,rotationandtorsionarespecifiedforpilegroupPL1andeachsoilgroupSOL1,andSOL2bytheTABRlines.

    ThefollowingarethreeoftheplotfilescreatedinSampleProblem3.AportionofthePSIlistingfilefollowsonthesubsequentpages.