ForewordIntroductionScopeNormative referencesTerms and definitionsSymbols and abbreviated termsSymbols for shallow and intermediate foundation designSymbols for pile foundation designSymbols for soil-structure interaction for auxiliary subsea structures, risers and flowlinesSymbols for design of anchors for stationkeeping systemsAbbreviated termsGeneral requirementsGeneralDesign cases and partial factorsRepresentative and design values of geotechnical parametersGuidelinesDetermination of representative and design values of soil parametersReliability-based geotechnical designTesting and instrumentationSite investigation, identification of geohazards and carbonate soilsGeneralGeological modelling and identification of hazardsGeneralAssessment of site geohazardsCarbonate soilsGeneralCharacteristic features and properties of carbonate soilsFoundations in carbonate soilsDriven piles and other deep foundation alternativesShallow foundationsAssessmentDesign of shallow and intermediate foundations for fixed structuresGeneralPrinciplesGeneral principlesFoundation embedmentSign conventions, nomenclature and action reference pointAcceptance criteriaMaterial and action factorsUse of partial factors in designDesign considerationsAdjusting for soil plug weightSkirt spacingFoundation base perforationsSkirtless foundations penetrating soft soilsTensile stresses beneath foundationsOmni-directional actionsInteraction with other structuresMultiple foundationsHydraulic stabilityScourPipingUnconventional soils or soil profilesSelection of soil parameter values for designParameters used in serviceability designWave-seabed interactionUltimate limit state (stability)Assessment of bearing capacity of shallow foundationsFailure mechanismsAction transferIdealization of foundation area and the effective area conceptUndrained conditions with constant shear strength with depthUndrained conditions with linearly increasing shear strength with depthUndrained conditions with a surface crust overlying linearly increasing shear strength with depthDrained conditionsAssessment of sliding capacity of shallow foundationsGeneralUndrained conditionsDrained conditionsHorizontal seabed resistance above foundation base levelAssessment of torsional capacityAssessment of capacity of intermediate foundationsServiceability limit state (displacements and rotations)GeneralServiceability of shallow foundations under static loadingGeneralImmediate displacements and rotationsPrimary consolidation settlementSecondary compression: creepDifferential displacements and rotationsServiceability of intermediate foundationsServiceability in response to dynamic and cyclic actionsAlternative methods of designYield surface approachRisk-informed decision makingInstallationGeneralSkirt penetration resistanceRequired and allowable under-pressureRelocation, retrieval and removalPile foundation designPile capacity for axial compressionGeneralAxial pile capacitySkin friction and end bearing in clay soilsSkin friction and end bearing in sandsSkin friction and end bearing in gravelsSkin friction and end bearing of grouted piles in rockSkin friction and end bearing of driven piles in intermediate soilsPile capacity for axial tensionAxial pile performanceStatic axial behaviour of pilesCyclic axial behaviour of pilesSoil reaction for piles under axial actionsAxial shear transfer t–z curvesEnd bearing resistance–displacement, Q–z curveSoil reaction for piles under lateral actionsGeneralLateral soil reaction for clayGeneralP-y curves for monotonic actionsGeneralUltimate soil resistance for isotropic conditionsAnisotropy correction of ultimate soil resistance for gapping conditionsP−y curve relationshipsP-y curves for cyclic actionsP-y curves for fatigue actionsP-y curves for earthquake actionsComparison with previous recommendationsLateral capacity for sandLateral soil resistance – displacement p–y curves for sandp–y curves for fatigue actions for sandsRefined assessment of lateral pile responseLateral soil resistance-displacement curves in calcareous soil, cemented soil and weak rockPile group behaviourGeneralAxial behaviourLateral behaviourPile installation assessmentGeneralDrivability studiesObtaining required pile penetrationDriven pile refusalPile refusal remedial measuresReview of hammer performanceRe-evaluation of design penetrationModifications to piling proceduresGeneralPlug removalSoil removal below the pile tipTwo-stage driven pilesSelection of pile hammer and stresses during drivingUse of hydraulic hammersDrilled and grouted pilesGrouting pile-to-sleeve connectionsPile installation dataInstallation of conductors and shallow well drillingAssessment of pile capacity for existing structuresGeneralGeotechnical and foundation dataGeotechnical dataDesign dataInstallation dataCondition dataOperational dataEvaluationAssessmentGeneralPushover response of pile foundation systemsTime-dependent effects on pile foundationsGeotechnical design input to subsea structures, risers and flowlinesGeneralGeotechnical investigationFoundations for subsea production structuresSteel catenary risersGeneralSeabed characterisationDesign for ultimate limit stateDesign for fatigue limit stateGeneralSelection of s below SCRTrenching effectsGeotechnical design for jetted conductors and top tension risersGeneralJetted conductorsGeneralShort-term axial bearing capacityLong-term axial bearing capacitySoil-structure interaction for well integrity assessmentGeotechnical input to well strength assessmentClaysSandsGeotechnical input to well fatigue assessmentGeneralClaysSpring-only methodSpring-dashpot methodSandsGeotechnical considerations in conductor driving analysisFoundation design for riser towersGeneralFoundation optionsLoading actions and safety factorsLoading actionsRecommended safety factorsDesign challengesOffshore pipelines and flowlinesGeotechnical pipe-soil interaction (PSI) analysisGeneralBuried pipelines and flowlinesUnburied pipelines and flowlinesSeabed and seafloor characterisationSubmarine slides and density flows: simulation and pipeline impact analysisDesign of anchors for floating structuresAdditional information and guidance (informative)Guidance on scopeGuidance on normative referencesGuidance on terms and definitionsGuidance on symbols and abbreviated termsGuidance on general requirementsGeneralDesign cases and partial factorsRepresentative and design values of geotechnical parametersGuidelinesDetermination of the representative and design values of soil parametersReliability-based geotechnical designTesting and instrumentationGuidance on site investigation, identification of geohazards and carbonate soilsGeneralGeological modelling and identification of hazardsCarbonate soilsGeneralCharacteristic features and properties of carbonate soilsFoundations in carbonate soilsDriven piles and other deep foundation alternativesShallow foundationsAssessmentGuidance on design of shallow and intermediate foundations for fixed structuresGeneralPrinciplesGeneral principlesFoundation embedmentSign conventions, nomenclature and action reference pointAcceptance criteriaMaterial and action factorsUse of partial factors in designDesign considerationsAdjusting for soil plug weightSkirt spacingFoundation base perforationsSkirtless foundations penetrating soft soilsTensile stresses beneath foundationsOmni-directional loadingInteraction with other structuresMultiple foundationsHydraulic stabilityScourPipingUnconventional soils or soil profilesSelection of soil parameters for designParameters used in serviceability designWave-seabed interactionUltimate limit state (stability)Assessment of bearing capacity of shallow foundationsFailure mechanismsAction transferIdealization of foundation area and the effective area conceptUndrained conditions with constant shear strength with depthBearing capacity factorsBearing capacity correction factorsUndrained conditions with linearly increasing shear strength with depthUndrained conditions with a surface crust overlying linearly increasing shear strength with depthDrained conditionsBearing capacity factorsBearing capacity correction factorsExclusion of effective cohesion from bearing capacity formulaeAssessment of sliding capacity of shallow foundationsGeneralUndrained conditionsDrained conditionsHorizontal seabed resistance above foundation base levelAssessment of torsional capacityAssessment of capacity of intermediate foundationsServiceability limit state (displacements and rotations)GeneralServiceability of shallow foundations under static loadingGeneralImmediate displacements and rotationsPrimary consolidation settlementSecondary compression: creepDifferential displacements and rotationsServiceability of intermediate foundationsServiceability in response to dynamic and cyclic actionsAlternative methods of designYield surface approachGeneralApplication to designYield surfaces for selected casesUndrained conditionsSurface foundations with zero-uplift capacity along the foundation–soil interfaceSurface foundations with unlimited-uplift capacity along the foundation–soil interfaceEmbedded foundationsDrained conditionsGeneralSurface foundationsEmbedded foundationsRisk-informed decision makingInstallationGeneralSkirt penetration resistanceRequired and allowable under-pressureRelocation, retrieval and removalGuidance on pile foundation designPile capacity for axial compressionGeneralAxial pile capacitySkin friction and end bearing in clay soilsGeneralAxial pile capacity in clayLoading test database for piles in clayUnified CPT method for pile axial capacity in claysEstablishing representative strength and effective overburden stress profilesPile length effectChanges in axial capacity in clay with timeSkin friction and end bearing in sandsGeneralParameter value assessmentFormer main text method in sandsSkin friction and end bearing in gravelsSkin friction and end bearing of grouted piles in rockSkin friction and end bearing of driven piles in intermediate soilsPile capacity for axial tensionAxial pile performanceStatic axial behaviour of pilesCyclic axial behaviour of pilesQualificationActionsCyclic effectsAnalytical modelsGeneralDiscrete element modelsContinuum modelsSoil characterisationAnalysis procedureActionsPile propertiesSoil propertiesCyclic analysesSoil reaction for piles under axial compressionAxial shear transfer t–z curvesEnd bearing resistance–displacement, Q–z curveSoil reaction for piles under lateral actionsGeneralLateral soil reaction for clayGeneralp–y curves for monotonic actionsGeneralUltimate soil resistance for isotropic conditionsAnisotropy correction of ultimate soil resistance for gapping conditionsP-y curve relationshipsP-y curves for cyclic actionsP-y curves for fatigue actionsP-y curves for earthquake actionsComparison with previous recommendationsLateral capacity for sandLateral soil resistance-displacement p-y curves for sandp–y curves for fatigue actionsRefined assessment of lateral pile responsePile group behaviourGeneralAxial behaviourLateral behaviourPile installation assessmentGeneralDrivability studiesObtaining required pile penetrationDriven pile refusalPile refusal remedial measuresSelection of pile hammer and stresses during drivingUse of hydraulic hammersDrilled and grouted pilesGrouting pile-to-sleeve connectionsPile installation dataInstallation of conductors and shallow well drillingGuidance on assessment of pile capacity for existing structuresGeneralGeotechnical and foundation dataEvaluationAssessmentGeneralPushover response of pile foundation systemsTime-dependent effects on pile foundationsGuidance on geotechnical design input to subsea structures, risers and flowlinesGeneralGeotechnical investigationFoundations for subsea production structuresSteel catenary risersGeneralSeabed characterisationDesign for ultimate limit stateDesign for fatigue limit stateGeneralElastic spring modelNon-linear spring modelsSelection of s below SCRTrenching effectsCyclic and consolidation effectsGeotechnical design for jetted conductors and top tension risersGeneralJetted conductorsGeneralShort-term axial bearing capacityLong-term axial bearing capacitySoil-structure interaction for well integrity assessmentGeotechnical input to well strength assessmentGeotechnical input to well fatigue assessmentGeneralClaysSpring-only methodSpring-dashpot methodSandsGeotechnical considerations in conductor driving analysisConductor pipe installationMinimum wall thicknessGeneralDuring drivingDriving fatigueConductor tip damage and bucklingGeneralDamage during drivingInstallation with inclined shoesFoundation design for riser towersGeneralFoundation optionsLoading actions and safety factorLoading actionsRecommended safety factorsDesign challengesGeneral principlesAssessment of effect of sand layers on suction anchorsInspection and monitoringOffshore pipelines and flowlinesGeotechnical pipe-soil interaction (PSI) analysisGeneralBuried pipelines and flowlinesUnburied pipelines and flowlinesActions on pipelinesGeneralDetermination of PSI input parametersDrained and undrained behaviour during pipe-soil interactionAxial soil resistancePerformance evaluation stageSediment transport and scourDamping from pipeline-seabed interaction in free span analysisSubmarine slides and density flows: simulation and pipeline impact analysisGeneralRheology characterizationFlow simulationMobilised shear strength of slide / flow materialImpact forces on pipelinesAdditional considerationsIntervention structuresGuidance on geotechnical design of anchors for floating structuresGeneralSoil investigationAnchor typesDrag embedment anchorsDriven anchor pilesSuction anchor pilesPlate anchorsGeneralDrag-embedded plate anchorsDirect-embedded plate anchorsGravity anchorsGravity-embedded (free-falling) anchorsGeotechnical design of drag anchorsGeneralEffect of shear strength gradient in clayEffect of lead-line type in clayEffect of cyclic loading in clayEffect of anchor soaking in clayCapacity in clay under inclined line loadingDrag distance and penetration depth in soft clayNew anchor designsAnalytical tools for anchor performance evaluationAnchor holding capacity in sandAnchor holding capacity in soils other than soft clay and sandHolding capacity generated by friction along the mooring lineInstallation of drag anchorsOut-of-plane loading of anchorsGeotechnical design of anchor pilesDriven anchor pilesBasic considerationsSafety factors for driven anchor pilesBasic considerations for structural strength designInstallation of driven anchor pilesDesign of suction anchor pilesBasic considerationsAnalysis methodsPenetration analysisRemoval analysisHolding capacityIncrease of side friction with timeCoupling between horizontal and vertical capacitySafety factors and allowable actions for suction anchor pilesOther special considerationsBasic considerations for structural strength designInstallation of suction anchorsGeotechnical design of plate anchorsBasic considerationsPrediction method for drag-embedded plate anchorsGeneralAnchor line mechanicsInstallation performanceHolding capacity performanceFactors of safety for drag-embedded plate anchorsPrediction method for direct-embedded plate anchorsInstallation of plate anchorsInstallation tolerancesDrag-embedded plate anchorsDirect-embedded plate anchorsOut-of-plane loading of plate anchorsGeotechnical design of other types of anchorsGravity anchorsGeneral considerationsSliding resistanceUplift resistanceGravity-embedded anchorsBasic considerationsImpact velocity predictionGeotechnical design and analysisInstallation penetrationCyclic actionsOut-of-plane loadingSafety factors for gravity-embedded anchorsInstallation of gravity-embedded anchorsPre-tensioning of mooring lines and test loading of anchorsGeneralPermanent mooringsMobile (temporary) mooringsTest loading for drag anchorsTest loading for anchor piles and plate anchorsTest loading for gravity-embedded anchorsBibliography