part iii facilities, chapter 5 mooring facilities · 2017-08-15 · part iii facilities, chapter 5...

PART III FACILITIES, CHAPTER 5 MOORING FACILITIES

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(2)Embedment length of sheet pilewalls for permanent situations and variable situations in respect of Level 1earthquakegroundmotion

① Themechanical behavior of the sheet pilewall varies depending on the embedment length. With a shortembedmentlengththebehaviorcharacteristicsarefreeearthsupportconditions,andwithalongembedmentlengththebehaviorcharacteristicsarefixedearthsupportconditions.Inordertoensurestabilityofthesheetpilewallunderpermanentsituationsandvariablesituations,Itispreferablethatthebottomofthesheetpileisfixedsufficientlyintheground,inotherwordsthatfixedearthsupportconditionsbesatisfied.Conventionally,theembedmentlengthwasobtainedbythefreeearthsupportmethodbasedonclassicalearthpressuretheory.Takahashi and Kikuchi 49) showed that the embedment length obtained with this method by consideringappropriatepartialfactorsisconsideredtobefixedearthsupportcondition.Also,theequivalentbeammethodforobtainingthecross-sectionofsheetpilesassumesfixedearthsupportconditions.

② Iftheembedmentlengthofsheetpilesistoobtainbythefreeearthsupportmethod,analysisoftheembedmentlengthofthesheetpilewallcanbecarriedoutusingthefollowingequation.Thisequationisobtainedfromtheequilibriumofmomentsoftheearthpressureandresidualwaterpressureaboutthepointofinstallationoftheties,asshowninFig. 2.3.3.Inthefollowingequation,thesymbolγisthepartialfactorcorrespondingtoitssubscript,wherethesubscriptskanddindicatethecharacteristicvalueandthedesignvalue,respectively.

(2.3.7)

where, Pp :resultantpassiveearthpressureactingonthesheetpilewall(kN/m) Pa :resultantactiveearthpressureactingonthesheetpilewall(kN/m) Pw :resultantresidualwaterpressureactingonthewallstructure(kN/m) Pdw :resultantactivewaterpressureactingonthewallbody(kN/m)(onlyduringearthquakes) a–d :distancebetweenthepositionofinstallationofthetierodandthepointofactionoftheresultant

force(m) γa :structuralanalysiscoefficient

Incalculating thedesignvaluesof earthpressure in theequation, the tangentof theangleof shearingresistancetanφ,thecohesionc,thewallsurfacefrictionangleδ,theeffectiveunitweightw',thesurchargeq,andtheseismiccoefficientforverificationduringearthquakesonlykhmaybecalculatedusingequation(2.3.8),andPart II, Chapter 5, 1 Earth Pressuremaybeusedforreference.Thedesignvalueofresidualwaterpressuremaybecalculatedasappropriateby reference toPart II, Chapter 5, 2.1 Residual Water Pressure,aftercalculatingthedesignvalueofresidualwaterlevelfromequation(2.3.8),takingthetidelevelandtidaldifferenceatthefrontsurfaceintoconsideration.Also,thedesignvalueofdynamicwaterpressureused in theperformanceverificationduringanearthquakemaybecalculatedas appropriateby referencetoPart II, Chapter 5, 2.2 Dynamic Water Pressure, after first calculating the design value of seismiccoefficientforverificationfromequation(2.3.8).ThepartialcoefficientsusedincalculationofthedesignvaluesmaybeobtainedbyreferencetoTable 2.3.3.

(2.3.8)

③ Incohesivesoilground,normallyifequation(2.3.9)isnotsatisfied,stabilityofembedmentisnotensured.

(2.3.9)where,

c :cohesionofthesoilattheseabed(kN/m2) q :surcharge(kN/m2) wi :weightofthesoiloftheithstratumabovetheseabedsurface,forbelowtheresidualwaterlevel,

theweightinwater(kN/m2) ρw :densityofseawater(t/m3) g :gravitationalacceleration(m/s2) hw :differenceinwaterlevelbetweentheresidualwaterlevelandthefrontsurfacetidelevel(m)

Thedesignvaluesintheequationmaybecalculatedfromthefollowingequation.

(2.3.10)

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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN

Whenequation(2.3.9)isnotsatisfiedbecausethesoilsattheseabedareweak,theneithertheseabedsoilsshouldbeimprovedbyanappropriatemethod,orastructuresuchasasheetpilewallwitharelievingplatformshouldbeadopted.

④ Characteristicembedmentlengthconsideringtherigidityofthesheetpilewallcross-section

(a) According to the elastic beam analysismethod described in (1)④ above, the behavior characteristics ofasheetpilewallcanvarydependingon theembedment length. Inotherwords, if thesheetpiling isnotlongerbyacertainvalue, thesheetpilewallwillnotbestable. Theembedment length thatbringsaboutthelimitingstabilitystateiscalledthelimitingembedmentlengthDC. Iftheembedmentlengthislongerthanthelimitingembedmentlength,theflexuralmomentinthesheetpilewallbecomesthepeakmaximumflexuralmomentMPunderfreeearthsupportconditions.TheembedmentlengthobtainedaboveiscalledthetransitionembedmentlengthDP.Iftheembedmentlengthisincreasedfurther,theflexuralmomentbecomestheconvergentmaximummomentMFunderfixedearthsupportconditions.TheminimumembedmentlengthatwhichthisisachievediscalledtheconvergentembedmentlengthDF.

(b)FlexibilitynumberofthesheetpileAsameasuretoindicatetherigidityofasheetpilewallasastructure,thefollowingflexibilitynumberintheequation(2.3.11)proposedbyRoweisused:

(2.3.11)where

ρ :flexibilitynumber(m3/MN) H :totallengthofsheetpile(m) E :Young’smodulusofthesheetpile(MN/m2) I :geometricalmomentofinertiaperunitwidthofthecross-sectionofthesheetpile(m4/m)

ForHinρ=H4/EI,RoweusesthesumoftotalheightofthesheetpilewallfromtheseabottomtothetopofthesheetpilewallHandtheembeddedlengthD offixedearthsupportstateasthetotallengthofsheetpile.Also,TakahashiandKikuchiEtal.suggestanewindexcalledthesimilaritynumberthatisderivedbyusingtheflexibilitynumberandgroundcharacteristics.TheheightHT fromtheseabottomtothetierodinstallationpointisusedforthelengthH inthisequation:

(2.3.12)where,

ω :similaritynumber ρ :flexibilitynumber(m3/MN) h :modulusofsubgradereactionofthesheetpilewall(MN/m3) HT :heightfromthetieinstallationpointtotheseabedsurface(m) E :Young’smodulusofthesheetpile(MN/m2) I :geometricalmomentofinertiaperunitwidthofthecross-sectionofthesheetpile(m4/m)

Byexpressingthemechanicalcharacteristicsofasheetpilewallwithasimilaritynumber,theeffectoftherigidityofthesheetpilescanbeestimatedquantitatively.

(c)ModulusofsubgradereactionofsheetpilesThereareaveryfewreferencedatathatgivesmeasuredorsuggestedvaluesofmodulusofsubgradereactionof thesheetpileh. Therefore it ispreferable toobtain thesevaluesbymeansofmodel testsand/orfieldmeasurements. The proposed values that have traditionally been used include the values proposed byTerzaghiandtheonesproposedbyTakahashiandKikuchi,etal.,whichhavebeenobtainedbymodifyingTerzaghi’svalues.TheresearchconductedbyTakahashiandKikuchi,etal.showsthattheeffectoferrorsinthemodulusofsubgradereactionisnotfatalforpracticaluse.49)ThusthevaluesproposedbyTakahashiandKikuchi,etal.maynormallybeusedasthecoefficientofsubgradereactionofsheetpilewall.

1) ValuesproposedbyTerzaghi51)ThevaluesproposedbyTerzaghiareaslistedinTable 2.3.1.

Table 2.3.1 Modulus of Subgrade Reaction for Sheet Pile Wall in Sandy Ground (h)（MN/m3）

Relativedensityofsand Loose Medium Dense

Modulusofsubgradereaction(h) 24 38 58


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2) ValuesproposedbyTakahashiandKikuchi,etal.49)TakahashiandKikuchi,etal.confirmedthattheresultofTschebotarioff’smodeltestofsheetpilewall52)doesnotcontradictwiththevaluesproposedbyTerzaghi.TheyrelatedthemodulusofsubgradereactionlistedinTable 2.3.1 withtheN-value,usingtherelationshipbetweenthemodulusofsubgradereactionand the relativedensityproposedbyTerzaghiaswell as the relationshipbetween theN-valueand therelativedensity53)alsodemonstratedbyTerzaghi.ThentheyadoptedthesmallervalueofmodulusofsubgradereactiontobeonthesafesideandconnectedtheresultantvaluesusingasmoothlineasshowninFig. 2.3.9. TheyalsorelatedthemodulusofsubgradereactionwiththeangleofshearingresistanceasshowninFig. 2.3.10,usingoneequation(2.3.13)ofDunham’sequationsforcalculatingthesmallerangleofshearingresistanceforagivenN-value.

(2.3.13)

where, φ :angleofshearingresistance(°) N :N-value

However, it shouldbenoted thatFig. 2.3.10 isanexpedientgraph toacertaindegree,asDunham’sequationsincludecasesthatgivethelargerangleofshearingresistancedependingonthegrainsizeofsandysoil. Fig. 2.3.9 and2.3.10 alsoshowthevaluesproposedbyTerzaghiinadditiontothevaluesproposedbyTakahashiandKikuchi,atal.

1000

20

40

60

80

20 30 40 50

N-value

Values proposed by Terzaghi

Values proposed by Takahashi, Kikuchi, et al.

Mod

ulus

of s

ubgr

ade

reac

tion

h (M

N/m

3 )

Fig. 2.3.9 Relationship between Modulus of Subgrade Reaction(h)and N-value

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20150

20

40

60

80

25 30 35 40

Values proposed by Terzaghi

Values proposed by Takahashi, Kikuchi, et al.

Angle of ineternal friction (°)

Mod

ulus

of s

ubgr

ade

reac

tion

h (M

N/m

3 )

Fig. 2.3.10 Relationship between Modulus of Subgrade Reaction(h)and Angle of Internal Friction( )

(d)DeterminationoftheembeddedlengthofsheetpileusingRowe’smethodInthedeterminationoftheembeddedlengthofsheetpilesusingRowe’smethod,acharacteristicvaluethatsatisfiesequation(2.3.14)canbeused.Asequation(2.3.14)takesintoconsiderationthestiffnessofthesheetpilewithout theearthpressure,whenreducing theearthpressureof theexistingsteelsheetpilequaywallorsimilarimprovementmethod,itisnecessarytobeawarethattheearthpressurereductioneffectdoesnotnecessarilyresultinashorteningoftheembedmentlength.Therefore,whenconsideringtheearthpressurereductioneffect,itispreferabletoalsousethemethodsof①to④above.

(2.3.14)where

δs :ratiooftheembeddedlengthofsheetpiletotheheightofthetierodinstallationpointabovetheseabottom

DF :embeddedlengthofsheetpile(m) HT :heightofthetierodinstallationpointabovetheseabottom(m) ω :similaritynumber(=ρh) ρ :flexibilitynumber(＝HT4/EI）（m3/MN） E :Young’smodulusofsheetpile(MN/m2) I :geometricalmomentofinertiaofsheetpilewallperunitwidth(m4/m) h :modulusofsubgradereactiontosheetpilewall(MN/m3)

Theembeddedlengthcalculatedwiththisequationistheconvergedembeddedlength.AccordingtothestudyconductedbyTakahashiandKikuchi,etal.anincreaseofjusta2%–plusinthemaximumflexuralmoment occurs when an embedded length corresponding to 70% of the converged embedded length isemployed.Thereforetheuseoftheconvergedembeddedlengthasthedesignembeddedlengthsecuresthesafety,andthereisnoneedtoconsideramarginagainstthesafety. Equation (2.3.14) formulates the relationship between the ratio of the convergent embedment lengthDF to thevirtualwallheightHT,δ＝(DF/HT), and the similaritynumberω shown inFig. 2.3.11. This isbasedonanalysiscarriedoutbyTakahashiandKikuchi,atal.usingasimulationmodelfor72caseswithacombinationofconditions forwaterdepthof thequay (–4 to–14m), soil conditions, seismicconditions(kh=0.2), andmaterial conditions of the steel sheet piles. InFig. 2.3.11, δ for permanent situations andearthquakeconditionsareobtainedasδN and δSrespectively,butinequation(2.3.14)δSisusedfortheactionofearthquakesbecauseitindicateslargevalues. Also,inthisanalysisbyTakahashiandKikuchi,etal.therelationshipbetweenthesimilaritynumber,theratioµ (＝MF/MT),andtheratioτ(＝TF/TT)werestudied.TheratioµistheratioofthemaximumflexuralmomentMFwhenthereisconvergentembedmentlengthDFinthebendingcurveanalysistothemaximumflexuralmomentMTcalculatedbytheequivalentbeammethodassumingthetie installationpointandtheseabedsurfaceasthesupportpoints.TheratioτistheratiooftietensionforceTFwhenthereisconvergent


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embedmentlengthDF inthebendingcurveanalysistothetietensionforceTTcalculatedfromthevirtualbeammethod.TheserelationshipsareshowninFigs. 2.3.12to2.3.13.

Fig. 2.3.11 Relationship between ω and δ

Perm

anen

t sta

tes

Dur

ing

seis

mic

mot

ions

Fig. 2.3.12 Relationship between µ and ω

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Perm

anen

t sta

tes

Dur

ing

seis

mic

mot

ions

Fig. 2.3.13 Relationship between τand ω

(3)FlexuralMomentofSheetPilesandReactionatTieMemberInstallationPoint

① Themaximumflexuralmomentofsheetpilesandreactionatthetiememberinstallationpointshallbecalculatedwithanappropriatemethodthattakesintoconsiderationtherigidityandembeddedlengthofthesheetpilesandthecharacteristicsoftheground.

② ThemaximumflexuralmomentandreactionforceatthetiememberinstallationpointofsheetpilesmaybedeterminedusingtheequivalentbeammethoddescribedbeloworRowe’smethod.However,careshouldbeexercisedwhenusingtheequivalentbeammethod,becausethesectionforcesmaybeunderestimatedwhentherigidityofthesheetpilesishigh.

③ EquivalentBeamMethodTheequivalentbeammethodcalculatesthemaximumflexuralmomentandreactionforceatthetiememberinstallationpointofthesheetpilesbyassumingasimplebeamsupportedatthetiememberinstallationpointandtheseabottomwiththeearthpressureandresidualwaterpressureactingastheloadabovetheseabottom(seeFig. 2.3.14).

L.W.L.Reaction at the tie rod point (Ap)

Tie member

Act

ive

earth

pre

ssur

eA

ctiv

e ea

rth p

ress

ure

Residualwater pressure

Residual water level

Fig. 2.3.14 Equivalent Beam for Obtaining Flexural Moment


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④ The seabed surface used in calculating the flexural moment should take margin of the depth intoconsideration.

⑤ Thedesignvaluesofmaximumflexuralmomentinthesheetpilewallandthereactionforceatthetiememberinstallation point can normally be calculated using the following equation. In the following equation, thesubscriptdindicatesthedesignvalue.

(a) Reactionforceatthetieinstallationpoint

(2.3.15)

where, Ap :reactionforceatthetieinstallationpoint(kN/m) Pa :resultantactiveearthpressurefromthetopofthesheetpilingtotheseabedsurface(kN/m) Pw :resultantresidualwaterpressurefromthetopofthesheetpilingtotheseabedsurface(kN/m) Pdw :resultantdynamicwaterpressureactingonthesheetpilewall(kN/m)(onlyduringearthquakes) a–c :distancefromtheinstallationpositionofthetiemembertothepointofactionoftheresultant

force(m) L :distancefromtheinstallationpositionofthetiemembertotheseabedsurface(m)

(b)Maximumflexuralmoment

(2.3.16)where,

Ap :reactionatthetieinstallationpoint(kN/m) P'a :resultantactiveearthpressurefromthetopofthesheetpiletothepositionwheretheshearforce

Sbecomes0(kN/m) P'w :resultantresidualwaterpressurefromthetopofthesheetpiletothepositionwheretheshear

forceSbecomes0(kN/m) P'dw :resultantdynamicwaterpressurefromthetopofthesheetpiletothepositionwheretheshear

forceSbecomes0(kN/m)(duringanearthquakeonly) a :distancefromthepositionwhere theshearforceSbecomes0 to the tiemember installation

position(m) b–d :distance from the positionwhere the shear forceS becomes 0 to the point of action of the

resultantforce(m)

Thedesignvaluesofearthpressure,residualwaterpressure,andresultantdynamicwaterpressureforcemaybeappropriatelycalculatedbyreferencetoPart II, Chapter 5, 1 Earth Pressure. Part II, Chapter 5, 2.1 Residual Water Pressure,andPart II, Chapter 5, 2.2 Dynamic Water Pressure,aftercalculatingthedesignvaluesof the tangentof theangleof shearing resistance tanφ, thecohesionc, thewall surfacefrictionangleδ,theeffectiveunitweightw',thesurchargeq,theseismiccoefficientforverificationduringearthquakesonlykh,andtheresidualwaterlevelRWL,fromequation(2.3.8).

⑥When themaximumflexuralmomentofsheetpilesand the tiemember installationpoint reactionforceareto be determined taking the effects of themodulus of subgrade reaction and the rigidity of the sheet pilesintoconsideration,thefollowingmethodcanbeused.Themaximumflexuralmomentandreactionforcearecalculatedbyusing theequivalentbeammethodand thecorrection factorsobtained fromFigs. 2.3.12and2.3.13aremultipliedby thosevalues. Theseismiccoefficient forperformanceverificationpurposesshowninFigs. 2.3.12 and2.3.13 has been set at 0.20. Values obtained from these figuresmay be used for theperformanceverificationforvariablesituationinrespectofLevel1earthquakegroundmotionunlessaverydetailedverificationisrequired.

(4)VerificationofStressesintheSheetPileWallforPermanentSituationandVariableSituationinrespectofLevel1earthquakegroundmotion

① Analysisofstressesinthesheetpilewallmaybecarriedoutusingthefollowingequation.Inthefollowingequation,thesymbolγisthepartialfactorcorrespondingtoitssubscript,wherethesubscriptskanddindicatecharacteristicvalueandthedesignvaluerespectively.

(2.3.17)

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where, σy :bendingyieldstressofthesteelmaterial(N/mm2) Mmax :maximumflexuralmomentinthesheetpilewall(Nmm/m) Z :sectionmodulusofthesteelmaterial(mm3/m) γa :structuralanalysisfactor(seeTable 2.3.3)

Equation(2.3.18)maybeusedforcalculatingthedesignvaluesofbendingyieldstressofthesteelmaterialin theequation. Forthedesignvalueof themaximumflexuralmomentinthesheetpilewall,refer to(3) Flexural Moment of Sheet Piles and Reaction at Tie Member Installation Point.

(2.3.18)

② Thejointlengthofsteelsheetpilesshouldbeaslongaspossible,fromthepointofviewofmaintainingtheintegrityofthesheetpiles.However,takingintoconsiderationdamagetothejointsduringconstruction,thejointsdonotnormallyextendtothebottomsofthesheetpiles.Normallythebottomendofthejointisatthedepthwheretheactiveearthpressurestrengthandthepassiveearthpressurestrengthareequal,oriscontinuoustothevirtualfixitypoint(1/β, refertothevirtualfixingpointshowninChapter 5, 5.2.2 Setting of Basic Cross-section),andisfrequently2–3mbelowtheseabedsurface.Iftheresidualwaterleveldifferenceislarge,thejointlengthofsteelsheetpilesshouldbedeterminedtakingthepipingphenomenonintoaccount.Thetopendofthejointisoftenextendedupto30–40cmabovethebottomsurfaceofthesuperstructure.

③ WhenU-shapedSteelsheetpileissubjectedtobending,thereisapossibilitythatverticalslipoccuratjointswhichlocateatthecenterofthewall.Inthiscase,theU-shapedsteelsheetpileswillnotactintegrallywiththeadjacentsheetpiles.Inthissituationthesectionmodulusandthegeometricalmomentofinertiaofthecross-sectioncalculatedassumingthesteelsheetpilesactintegrallyinthewallmaynotbeobtained.Methodsforevaluatingtheeffectofthisslipinthejointsincludethemethodofreducingthecross-sectionperformancebymultiplyingbyajointefficiencycoefficient.55),56)

(5)VerificationofStressesintheTieMembersunderPermanentSituationandVariableSituationsinrespectofLevel1earthquakegroundmotion

① Analysis of stresses in the tiemembersmaybe carriedout using the following equation. In the followingequation,thesubscriptdindicatesthedesignvalue.

(2.3.19)

where, σy :yieldstressintensioninthetiemember(N/mm2) Td :tensionforceintiemember(N) A :cross-sectionalareaoftiemember(mm2) γa :structuralanalysisfactor

Equation(2.3.18)maybeusedforcalculatingthedesignvalueoftensileyieldstressofthetiememberintheequation.Forthedesignvalueofthetensionforceinthetiemember,referto② Tension force of tie member,below.

② Tensionforceoftiemember

(a) Thetensionactingonatiemembercanbecalculatedbasedonthereactionattieinstallationpointcalculatedinaccordancewith(3) Flexural Moment of Sheet Pile and Reaction at Tie Member Installation Point above.Inthiscase,thereactionattiememberinstallationpointshouldbecalculatedbytakingtherigidityof thesheetpilewallcrosssectionintoconsideration. Takenotethat thetiemembertensionforcethat iscalculatedinaccordancewith(3) Flexural Moment of Sheet Pile and Reaction at Tie Member Installation Point aboveis thetensionforcepermeterofquaywall length. Tiemembersareusuallyinstalledatfixedintervals,andinsomecases,tiemembersmaybeattachedatacertainanglewiththelineperpendiculartothesheetpilewalltoavoidtheexistingstructurelocatedbehindthewall.Therefore,itisnecessarytocalculatethetiemembertensionforceconsideringthesesiteconditions.

(b)Thetensionforcethatactsonatiememberisgenerallycalculatedbyequation(2.3.20).Intheequationbelow,subscriptd standsforthedesignvalue.

(2.3.20)where

T :tensionforceoftiemember(kN)


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Ap :reactionatthetiememberinstallationpoint (kN/m) :tiememberinstallationinterval(m) θ :inclinationangleoftiemembertothelineperpendiculartothesheetpilewall(°)

(c) Insomecases,bollardsareinstalledonthecopingofasheetpilewallandthetractiveforcesofshipsactingonthebollardsaretransmittedtothetiemembers. Usually,thecopingisassumedtobeabeamwiththetiemembersaselasticsupportsandthetiemembertensionforcemaybecalculatedusingequation(2.3.21),assumingthatthetractiveforceisevenlysharedbyfourtiemembersnearabollard.Intheequationbelow,subscriptd standsforthedesignvalue.

(2.3.21)where

T :tensionforceactinginthetiemember(kN) Ap :reactionforceattheinstallationpointofthetiemember(kN/m) :spacingofinstallationoftiemembers(m) θ :inclinationangleoftiememberinperpendiculartothesheetpilewallandthetiemember(°) P : horizontalcomponentofthetractiveforceofshipactingonabollard(kN)

RefertoPart II, Chapter 8, 2.4 Actions due to Traction by Ships fordetailsontractiveforcesofships.

③ Tierods

(a) Fortheyieldstressoftierods,refertoTable 2.3.2.

(b)Thetensilestressinthetierodiscalculatedusingthecross-sectionfromwhichtheamountofcorrosionhasbeendeducted.Fortheamountofcorrosion,refertoPart II, Chapter 11, 2.3.2 Corrosion Rates of Steel.

④ TiewiresInsteadoftierods,so–calledtiewiremaybeused,thatismadefromhardenedsteelwirehavingcharacteristicsequivalenttohardenedsteelwire(JISG3506),orPCsteelwirehavingcharacteristicsequivalenttopianowire(JISG3502).

Table 2.3.2 Characteristics of Tie Rod Materials

TypeRupturestrength

(N/mm2)Yieldstress(N/mm2)

Elongation(%)

Yieldstress/rupturestrength

SS400 ≥402(dia.40mmorless)

≥235≥24 0.58

(dia.>40mm)≥215

≥24 0.53

SS490 ≥490(dia.40mmorless)

≥275≥21 0.56

(dia.>40mm)≥255

≥21 0.52

Hightensilestrengthsteel490

≥490 ≥325 ≥24 0.66


≥590 ≥390 ≥22 0.66


≥690 ≥440 ≥20 0.64


≥740 ≥540 ≥18 0.73

(6)VerificationofStressesinWale

① Analysisofstressesinwalingmaybecarriedoutusingthefollowingequation.Inthefollowingequation,thesubscriptdindicatesthedesignvalue.Intheequation,allthepartialfactorsexceptthestructuralanalysisfactormaybetakentobe1.0.Thestructuralanalysisfactormaybetakentobe1.4forthepermanentsituations,and1.12forthevariablesituationsassociatedwithLevel1earthquakegroundmotion.

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(2.3.22)

where, σy :bendingyieldstressinthewaling(N/mm2) Mmax :maximumflexuralmomentinthewaling(Nmm/m) Z :sectionmodulusofthewaling(mm3) γa :structuralanalysisfactor

Equation (2.3.18)may be used to calculate the design value of bending yield stress of thewaling in theequation.Forthecalculationofthemaximumflexuralmomentinthewaling,referto②below.

② Variousequationsforcalculatingthemaximumflexuralmomentofwalehavebeenproposed.Themoment,however,shouldbedeterminedaccordingtoconditionsatthesitesothatthecrosssectionissafeandeconomical.Ingeneral,themaximumflexuralmomentofwalemaybecalculatedusingequation(2.3.23).Intheequationbelow,subscriptd standsforthedesignvalue.

(2.3.23)where

:maximumflexuralmomentofwale(kN·m) T :tensionforceofatiemembercalculatedinaccordancewith(5) ② Tension force of tie member

(kN) :tierodinstallationinterval(m)

Thisequationisobtainedbyanalyzingathree–spancontinuousbeamsupportedatthetiememberinstallationpointsandsubjectedtothereactionatthetieinstallationpoint(Ap)asauniformlydistributedload.

③Whenbollardsareinstalledonthecoping,itisnecessarytoverifytheperformanceofthewalenearoneofthebollardsusingatiemembertensionforcethattakesintoconsiderationthetractiveforceofshipinaccordancewith(5) ② Tension force of tie member above.However,whenthewaleisembeddedintothecoping,theeffectofthetractiveforceofshipmaybeignored.

(7)AnalysisofSlipFailureintheGroundunderpermanentsituationsForanalysisofslipfailureinthegroundofsheetpilesquaywalls,refertoanalysisofslipfailureinthegroundin2.2 Gravity-type Quaywalls.Inthiscase,theanalysisiscarriedoutforcircularslipfailurespassingbelowthebottomofthesheetpilewall.StandardvaluesofthepartialfactorsusedintheperformanceverificationareshowninTable 2.3.3.

(8)PartialFactorsforpermanentsituationsandvariablesituationsinrespectofLevel1earthquakegroundmotion

① Partialfactorsforthestandardsystemfailureprobabilitiesfortheembedmentlengthofsheetpilewalls,sheetpilewallstresses,tierodstresses,andcircularslipfailureforsheetpilequaywallsunderpermanentsituationsareshowninTable 2.3.3(a).Basedontheaveragesafetylevelfordesignmethodsofthepast,theaveragesystemreliabilityindexforstabilityofwallstructuresis5.6orwhenconvertedintoafailureprobability9.9×10–9,theaveragereliabilityindexforcircularslipfailureis6.0orwhenconvertedintoafailureprobability9.2×10–10.Whentheexpectedtotalcostexpressedbythesumoftheinitialconstructioncostandtheexpectedvalueoftherestorationcostduetocollapseistakenintoconsideration,thesystemreliabilityindexthatminimizestheexpectedtotalcostis3.6orwhenconvertedintoafailureprobability1.7×10–4forhighearthquake-resistancefacilities,and2.7orwhenconvertedintoafailureprobability4.0×10–forotherquaywalls.358)


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Table 2.3.3 Standard Partial Factors(a) Permanent situations (No. 1)

Highearthquake-resistancefacilities

OtherthanHighearthquake-resistancefacilities

TargetsystemreliabilityindexβT 3.6 2.7TargetsystemreliabilityindexβT 1.7×10–4 4.0×10–3

γ γ µ/X k V γ α µ/X k V

Embedm

entlengthofsh

eetpilewalls

Sandysoilground

γtanφ’ Tangentoftheangleofshearingresistance

0.65 1.000 1.00 0.100 0.75 1.000 1.000 0.100

γc’ Cohesion 1.00 0.000 1.00 0.100 1.00 0.000 1.000 0.100γw’ Effectiveunitweight 1.00 0.000 1.00 0.050 1.00 0.000 1.000 0.050γδ Wallsurfacefrictionangle 0.90 0.300 1.00 0.100 0.90 0.300 1.000 0.100γq Surcharge 1.00 – – – 1.00 – – –γ RWL Residualwaterlevel 1.00 0.000 1.00 0.050 1.00 0.000 1.000 0.050γa Structuralanalysisfactor 1.00 – – – 1.00 – – –

Cohesivesoilground

γtanφ’ Tangentoftheangleofshearingresistance

0.70 0.820 1.00 0.100 0.80 0.820 1.000 0.100

γc’ Cohesion 0.75 0.700 1.00 0.100 0.80 0.700 1.000 0.100γw’ Effectiveunitweight 1.05 –0.190 1.00 0.050 1.05 –0.190 1.000 0.050γδ Wallsurfacefrictionangle 0.95 0.120 1.00 0.100 0.95 0.120 1.000 0.100γq Surcharge 1.00 – – – 1.00 – – –γ RWL Residualwaterlevel 1.00 0.000 1.00 0.050 1.00 0.000 1.000 0.050γa Structuralanalysisfactor 1.00 – – – 1.00 – – –

Sheetpilewallstresses Sandysoilground

γtanφ ‘ Tangentoftheangleofshearingresistance

0.75 0.760 1.00 0.100 0.85 0.760 1.000 0.100

γc’ Cohesion 1.00 0.000 1.00 0.100 1.00 0.000 1.000 0.100γw’ Effectiveunitweight 1.05 –0.320 1.00 0.050 1.05 –0.320 1.000 0.050γδ Wallsurfacefrictionangle 1.00 0.000 1.00 0.100 1.00 0.000 1.000 0.100γq Surcharge 1.00 – – – 1.00 – – –γ RWL Residualwaterlevel 1.00 0.000 1.00 0.050 1.00 0.000 1.000 0.050γσy SY295，SY390，SKY490 1.00 0.720 1.20 0.065 1.00 0.720 1.200 0.065γσy SKY400 1.00 0.720 1.26 0.073 1.00 0.720 1.260 0.073γa Structuralanalysisfactor 1.00 – – – 1.00 – – –

Cohesivesoilground

γtanφ ‘ Tangentoftheangleofshearingresistance

0.80 0.500 1.00 0.100 0.85 0.500 1.00 0.100

γc’ Cohesion 1.00 0.000 1.00 0.100 1.00 0.000 1.00 0.100γw’ Effectiveunitweight 1.05 –0.250 1.00 0.050 1.05 –0.250 1.00 0.050γδ Wallsurfacefrictionangle 1.00 0.000 1.00 0.100 1.00 0.000 1.00 0.100γq Surcharge 1.00 – – – 1.00 – – –γ RWL Residualwaterlevel 1.00 0.000 1.00 0.050 1.00 0.000 1.00 0.050γσy SY295，SY390，SKY490 0.90 1.000 1.20 0.065 1.00 1.000 1.20 0.065γσy SKY400 0.95 1.000 1.26 0.073 1.00 1.000 1.26 0.073γa Structuralanalysisfactor 1.00 – – – 1.00 – – –

Stressesintiemem

bers

Sandysoil

ground

γσy HT690 0.60 0.750 1.13 0.070 0.65 0.750 1.13 0.070γσy SS400 0.65 0.750 1.26 0.073 0.70 0.750 1.26 0.073γa Structuralanalysis

coefficient1.00 – – – 1.00 – – –

Cohesiv

esoilg

round γσy HT690 0.55 0.940 1.13 0.070 0.60 0.940 1.13 0.070

γσy SS400 0.65 0.940 1.26 0.073 0.70 0.940 1.26 0.073γa Structuralanalysisfactor 1.00 – – – 1.00 – – –

–736–


Table 2.3.3　Standard Partial Factors(a) Permanent situations (No. 2)

Highearthquake-resistancefacilities

Otherthanhighearthquake-resistancefacilities

γ α µ/X k V γ α µ/X k V

Circularslipfailure

γc’ Soilstrength:cohesion 0.90 0.309 1.00 0.040 0.90 0.329 1.00 0.040

γtanφ’Soilstrength:tangentoftheangleofshearingresistance 0.90 0.398 1.00 0.040 0.90 0.396 1.00 0.040

γw1 Unitweightofsoilsabovetheseabedsurface 1.10 –0.259 1.00 0.030 1.10 –0.271 1.00 0.030

γw2 Unitweightofsandysoilstratabelowtheseabedsurface 0.90 0.314 1.00 0.030 0.90 0.312 1.00 0.030

γw3 Unitweightofcohesivesoilstratabelowtheseabedsurface 1.00 0.000 1.00 0.030 1.00 0.000 1.00 0.030

γq Surcharges 1.70 –0.467 1.00 0.400 1.60 –0.487 1.00 0.400γ RWL Residualwaterlevel 1.10 –0.040 1.00 0.050 1.10 –0.040 1.00 0.050

*1: α:sensitivityfactor,µ/Xk:deviationofaveragevalue(averagevalue/characteristicvalue),V:coefficientofvariation.*2: Itisnecessarytodeterminewhichisgoverninginthesoilcompositionofthefoundationsunderconsideration,thesandysoilstrataorthe

cohesivesoilstrata,andusethepartialfactorsappropriateforsandysoilgroundorcohesivesoilground.Forexample,ifitisdeterminedthatthesandysoilstrataaregoverning(sandysoilground),whenthereisathinstratumofcohesivesoil,verificationiscarriedoutusingthepartialfactorforthecohesionofasandysoilground.

*3: σyindicatestheyieldstrengthofthesteelmaterial,andthepartialfactorsareselectedinaccordancewiththetypeofsteelused.*4: Thedesignvalueof the tensionforce in the tiemember iscalculatedfromthedesignvalueof tiemember installationpoint reaction

obtainedfromtheverificationofstressesinthesheetpiles.*5: Theangleofshearingresistanceφ'whencalculatingearthpressureisobtainedfromφ'=arctan(γtanφ'･tanφ'k).*6: Forapplyingthepartialfactorstocircularslipfailure,refertothepointsofcautiongivenin Chapter 2, 3 Slope Stability, 3.1(7) Partial

Factors.

Table 2.3.3　Standard Partial Factors(b) Variable situations in respect of Level 1 earthquake ground motion

AllfacilitiesPerformancerequirement Serviceability

γ α µ/X k V

Embedm

entlengthofsh

eet

piledwalls

Sandysoilground

γtanφ’ Tangentoftheangleofshearingresistance 1.00 – – –γc’ Cohesion 1.00 – – –γw’ Effectiveunitweight 1.00 – – –γδ Wallsurfacefrictionangle 1.00 – – –γq Surcharge 1.00 – – –γRWL Residualwaterlevel 1.00 – – –γkh Seismiccoefficientforverification 1.00 – – –γa Structuralanalysisfactor 1.20 – – –

Stressesofsheetpiledwalls

Sandysoilground

γtanφ’ Tangentoftheangleofshearingresistance 1.00 – – –γc’ Cohesion 1.00 – – –γw’ Unitweight 1.00 – – –γδ Wallsurfacefrictionangle 1.00 – – –γq Surcharge 1.00 – – –γp Tractiveforces(duringtractionbyships) 1.00 – – –γ RWL Residualwaterlevel 1.00 – – –γkh Seismiccoefficientforverification 1.00 – – –γσy Steelmaterialyieldstress 1.00 – – –γa Structuralanalysisfactor 1.12 – – –

Stressesintiemembers

γσy Steelmaterialyieldstrength 1.00 – – –γa Structuralanalysisfactor 1.67 – – –

*1:Thedesignvalueofthetensionforceinthetiememberiscalculatedfromthedesignvalueofthetiememberinstallationpointreactionobtainedfromtheverificationofsheetpilingstresses.


–737–

② Itisnecessarytodeterminewhichisdominantinthesoilcompositionofthegroundunderconsideration,thesandysoilstrataorthecohesivesoilstrataground,andusethepartialfactorsasappropriate.Forexample,ifitisdeterminedthatthesandysoilstrataaredominant,whenthereisathinstratumofcohesivesoil,verificationiscarriedoutusingthepartialfactorforthecohesionofasandysoilground. Regardingthepartialfactorsofquaywallsotherthanhighearthquake-resistancefacilities,calculationsshallbecarriedoutusingapartialfactorof1.0orhigherforthesteelmaterialyieldstressforthestressesinsheetpilewalls insandysoilground. For theperformanceverificationof facilitiesother thanports, therearenoexamplesoftheuseofdesignvaluesofthesteelmaterialyieldstrengthgreaterthantheJISspecificationvalues.Therefore,insettingthepartialfactors,thepartialfactorforthetangentoftheangleofshearingresistancewithalargesensitivityfactorissettoavaluelargerthanthevaluecalculatedfromareliabilityanalysis.Inthiswaytheflexuralmomentinthesheetpilewallisreduced,andacorrectioniscarriedoutsothatthepartialfactorofthesteelmaterialstrengthis1.0.

③ Intheverificationofsheetpiledquaywalls,itisnecessarytotakeintoconsiderationboththeactiveandpassiveearthpressure.Also,thereareapproachesthatdonotnecessarilyevaluatetheresistanceonthepassivesideasearthpressureandratherevaluateasabeamonanelasticfoundation,sopartialfactorsarenotprovidedforearthpressureinTable 2.3.3.

(9)PerformanceVerificationofAnchoragesforSheetPileQuaywallsonVariableSituationsinrespectofLevel1earthquakegroundmotion

① Locationofanchoragework

(a) Inprinciple,thelocationoftheanchorageworkshallneedtobesetatanappropriatedistancefromthesheetpilewall toensure the structural stabilityof themainbodyof thewall andanchorage,dependingon thecharacteristicsoftheanchoragework.Normally,thefurtherthepositionofinstallationoftheanchorageworkfromthesurfaceofthesheetpilewall,themoreeffectiveinrestrainingdeformationofthesheetpilewallduringanearthquake.59)

(b)Thelocationoftheanchorageworkshouldbedeterminedappropriatelyinconsiderationofthestructuraltypeoftheanchoragework,becausethestabilityoftheanchorageworkitselfisaffectedbyitspositionandthelocationatwhichthestabilityisachievedvariesdependingonthestructuraltype.

(c) ThelocationofconcretewallanchorageispreferablydeterminedtoensurethattheactivefailureplanestartingfromtheintersectionofseabottomandsheetpilewallandthepassivefailureplaneoftheslabanchoragedrawnfromthebottomoftheanchoragedonotintersectbelowthegroundsurfaceasshowninFig. 2.3.15.

(d)Thelocationofverticalpileanchorageispreferablydeterminedtoensurethatthepassivefailureplanefromthe point of m1/3 below the tiemember installation point of the anchorage and the active failure planefromtheintersectionofseabottomandsheetpilesdonotintersectatthelevelbelowthehorizontalsurfacecontainingthetiememberinstallationpointattheanchorageasshowninFig. 2.3.16.Thevalueofm1isthedepthofthefirstzeropointofflexuralmomentforafree–headpilebelowthetiememberinstallationpoint,whilethehorizontalsurfacecontainingtheinstallationpointoftiememberattheanchorageisassumedasthegroundsurface.

Tie memberW.L.

Residualwater level

Activefailure plane

Slab anchorage

Passivefailure plane

Shee

t pile

Fig. 2.3.15 Location of Slab Anchorage Works

–738–


W.L.

3m1

Tie member

Residual waterlevelResidual waterlevel

Activefailure plane

Passivefailure planeSh

eet p

ile

Verticalpile anchorage

Fig. 2.3.16 Location of Vertical Pile Anchorage

(e) Thelocationofsheetpileanchoragemaybedeterminedinaccordancewiththelocationofverticalpilewhenthesheetpilescanberegardedasalongpile.Whenthesheetpilescannotberegardedasalongpile,thelocationofanchoragemaybedeterminedbyignoringthepartdeeperthanthelevelm1/2belowthetiememberinstallationpointatthesheetpileanchorageandthenapplyingthemethodofthelocationdeterminationofconcretewallanchorage.

(f) Forthemethodtoobtainthefirstzeropointoftheflexuralmomentoftheverticalpileanchorageandsheetpileanchorageandthemethodtodeterminewhetherasheetpileanchoragecanbeconsideredasalongpile,refertoPortandHarbourResearchInstitute’smethoddescribedinPart III, Chapter 2, 2.4 Pile Foundations, 2.4 .5 Estimation of Pile Behavior using Analytical Methods.

(g)For ordinary sheet pile quaywallswhose tiemembers run horizontally, an angle of –15ºmay be used asthewallfrictionangleinthedeterminationofthepassivefailureplanethatisdrawnfromtheverticalpileanchorageorsheetpileanchorage.

(h)Thelocationofcoupled-pileanchorageshouldbebehindtheactivefailureplaneofthesheetpilewalldrawnfromtheseabottomwhenitisassumedthatthetensionofthetiememberisresistedonlybytheaxialbearingcapacityofthepilesasshowninFig. 2.3.17.Whenthetensionofthetiememberisevaluatedtoberesistedbyboth theaxialand lateralbearingcapacity inconsiderationof thebending resistanceof thepiles, it isnecessarytolocatetheanchorageinaccordancewiththelocationoftheverticalpile.

(i) Thepartialfactorsusedindeterminingthepositionoftheanchorageworkmayallbetakentobe1.0.

W.L. Tie member

Residualwater levelResidualwater level

Activefailure plane

Shee

t pile

Coupled-pileanchorage

Fig. 2.3.17 Position of Coupled-Pile Anchorage

② Examinationofthestabilityofslabanchorage

(a) The height and placing depth of slab anchorage may be determined to satisfy equation (2.3.24), on theassumption that the tiemember tension forceand theactiveearthpressurebehind theslabanchorageareresistedbythepassiveearthpressureinfrontoftheslabanchorageasshowninFig. 2.3.18.Inthefollowingequations,symbolγrepresentsthepartialfactorforitssubscript,andsubscriptsdandkrespectivelystandforthedesignvalueandthecharacteristicvalue.Intheexaminationforthestabilityoftheslabanchorage,whencalculatingthereactionatthetiememberinstallationpointusingthepartialfactorassociatedwiththeverificationofsheetpilestressinTable 2.3.3,thepartialfactorcanbesetat2.1whenthestructuralanalysisfactorisatpermanentsituationand2.0whenitisatvariablesituationinrespectofLevel1earthquakegroundmotion.

(2.3.24)


–739–

where EP :resultantpassiveearthpressureactingonslabanchorage(N/m) AP :reactionatthetiememberinstallationpointcalculatedaccordingto(3) Flexural Moment of

Sheet Pile and Reaction at Tie Member Installation Point above,using thepartial factorassociatedwiththeverificationofsheetpilestressinTable 2.3.3(N/m)

EA :resultantactiveearthpressureactingonslabanchorage(N/m) γa :structuralanalysisfactor

Thedesignvaluesintheequationmaybecalculatedfromthefollowingequation.However,forcalculatingtheearthpressureactingonaslabanchored,normallyitisassumedthatthesurchargeactasshowninFig. 2.3.18,withactiveearthpressureconsideredandpassiveearthpressurenotconsidered.

=1.2(Permanentsituations),1.0(VariablesituationsinrespectofLevel1earthquakegroundmotion)

=1.0(Permanentsituations,variablesituationsinrespectofLevel1earthquakegroundmotion)

= 1.0 (Permanent situations, variable situations in respect of Level 1 earthquake groundmotion) (2.3.25)

KpKA

EA

Ap

Ep

q: Surcharge

Residual water level

Fig. 2.3.18 Forces Acting on Slab Anchorage

(b)Thewallsurfacefrictionangleusedincalculatingtheearthpressureisnormallyassumedtobe15°inthecaseofactiveearthpressureand0°inthecaseofpassiveearthpressure.However,inthecaseofadeadmananchor,anupwardactingtensionforceactsontheanchored,sothewallsurfacefrictionforceactsupwards,which is theoppositeof thenormalcaseofpassiveearthpressure,and thepassiveearthpressurewillbereduced.Inthiscasethewallsurfacefrictionangleisnormallyassumedtobe15°.

(c)When theactive failureplaneof the sheetpile and thepassive failureplaneof the slabanchoragedrawnin accordance with① Location of anchorage work above intersect below the ground surface level, itis preferable to consider the fact that the passive earth pressure acting on the vertical surface above theintersectionpointdoesnotfunctionasaresistanceforceasshowninFig. 2.3.19;itshouldbesubtractedfromthedesignvalueofEP ofequation(2.3.24).Whentheintersectionpointislocatedabovetheresidualwaterlevel,thepassiveearthpressuretobesubtractedmaybecalculatedusingequation(2.3.26)Inthefollowingequation,thesubscriptdindicatesthedesignvalue.

(2.3.26)where

w :weightofsoil(kN/m2) hf :depthfromthegroundsurfacetotheintersectionofthefailureplanes(m)

–740–


KP :coefficientofpassiveearthpressure

Thedesignvaluewdfortheweightofsoilisexpressedastheproductofthedesignvaluefortheunitweightofthesoillayerunderreviewandthedepthhffromthegroundsurfacetotheintersectionofthefailureplanes.

Active

failur

e surf

acePassive failure surface

Passive failure surface

Passive earth pressureto be deducted( Ep)∆

Fig. 2.3.19 Earth Pressure to be subtracted from the Passive Earth Pressure that Acts on Anchorage Wall when the Active Failure Plane of Sheet Pile Wall and the Passive Failure Plane of Slab Anchorage Intersect

(d)CrosssectionofslabanchorageSlabanchorageshouldhavestabilityagainst theflexuralmomentcausedbytheearthpressureandthe tiemembertension.Ingeneral,themaximumflexuralmomentmaybecalculatedbyassumingthattheearthpressure isapproximatedtoanequallydistributedloadandtheslabanchorageisacontinuousslabin thehorizontaldirectionandacantileverslabfixedatthetiememberinstallationpointintheverticaldirection,andthenusingequation(2.3.27).Inthefollowingequation,thesubscriptdindicatesthedesignvalue.

(2.3.27)where

MH :horizontalmaximumflexuralmoment(N·m) MV :verticalmaximumflexuralmomentpermeterinlength(N·m/m) T :tiemembertensionaccordingto(5) Verification of Stress in Tie Members under Permanent

Situation and Variable Situation in respect of Level 1 earthquake ground motion (N) :tiememberinterval(m) h :heightofslabanchorage(m)

ThelayoutofthereinforcingbarsforMH maybedeterminedontheassumptionthattheeffectivewidthoftheslabanchorageis2b withthetiememberinstallationpointasthecenter,whereb isthethicknessoftheslabanchorageatthetiememberinstallationpoint.

③ Examinationofstabilityofverticalpileanchorage

(a) Verticalpileanchoragemaybeverifiedforperformanceasverticalpilessubjectedtoahorizontalforceduetotiemembertension.

(b)Forthepartialfactorsusedintheperformanceverification,referto⑤ Partial factors.

④ Examinationofstabilityofcoupled-pileanchorage

(a) Coupled-pileanchoragemaybeverifiedforperformanceascoupledpilessubjectedtoahorizontalforceduetotiemembertension.

(b)Forthepartialfactorsusedintheperformanceverification,referto⑤ Partial factors.

⑤ PartialfactorsFor standard partial factors for use in the verification of the stability of vertical piles and coupled piles asanchorageforthepermanentsituationsandvariablesituationsinrespectofLevel1earthquakegroundmotion


–741–

adoptedforsheetpilequaywalls,refertothevaluesinTable 2.3.4.Partialfactorsaredeterminedtakingintoconsiderationthesettingofdesignmethodsofthepast.

Table 2.3.4 Standard Partial Factors(a) Permanent situations


γ α µ/X k V

Verticalpileanchorage Stress

γks ， γkc Lateralresistancecoefficient 1.00 – – –γσy Steelyieldstrength 1.00 – – –γa Structuralanalysisfactor 1.35 – – –

Coupledpile

anchorage

Stress

γw Weightofsuperstructure 1.00 – – –γws Weightofsoilonsuperstructure 1.00 – – –γq Surcharge 1.00 – – –γkch Modulusofsubgradelateralreaction 1.00 – – –γσy Steelyieldstrength 1.00 – – –γa Structuralanalysisfactor 1.45 – – –

Axialresistanceforce

γc’ Cohesion 1.00 – – –γN N-value 1.00 – – –

γRu ResistanceforcePull-outpiles 0.40 – – –Push-inpiles 0.45 – – –

γa Structuralanalysisfactor 1.00 – – –

*1: Thedesignvalueof tie tensionforce iscalculatedfromthedesignvalueof tiemember installationpoint reactionobtainedfromtheverificationofstressesinthesheetpile.

*2:Thedesignvalueofthepileaxialforcesusedinanalysisofbearingforcesincoupled-pileanchorageisobtainedfromtheverificationofstressesinthecoupledpiles.

*3:TheN-valuesandcohesionwhencalculatingthecharacteristicvalueofresistanceforceusedinanalysisofbearingforcesincoupled–pileanchoragearecharacteristicvalues.

Table 2.3.4　Standard Partial Factors(b) Variable situations in respect of Level 1 earthquake ground motion


γ α µ/X k V

Verticalpileanchorage

Stress

γks，γkc Lateralresistancecoefficient 1.00 – – –γσy Yieldstrengthofsteel 1.00 – – –γa Structuralanalysisfactor 1.12 – – –

Coupledpileanchorage

Stress

γw Weightofsuperstructure 1.00 – – –γws Weightofsoilonsuperstructure 1.00 – – –γq Surcharge 1.00 – – –γkch Modulusofsubgradelateralreaction 1.00 – – –γσy Yieldstrengthofsteel 1.00 – – –γa Structuralanalysisfactor 1.12 – – –

Bearingforces

γc’ Cohesion 1.00 – – –γN N-value 1.00 – – –

γRuResistanceforce

Pull-outpiles 0.40 – – –

Push-inpiles

Endbearingpiles 0.66 – – –Frictionpiles 0.50 – – –

γa Structuralanalysisfactor 1.00 – – –

*1: Thedesignvalueof tie tensionforce iscalculatedfromthedesignvalueof tiemember installationpoint reactionobtainedfromtheverificationofstressesinthesheetpile.

*2:Thedesignvalueofthepileaxialforcesusedinanalysisofbearingforcesinanchoredcoupledpilesisobtainedfromtheverificationofstressesinthecoupledpiles.

*3:TheN-valuesandcohesionwhencalculatingthecharacteristicvalueofresistanceforceusedinanalysisofbearingforcesincoupledpileanchoragearecharacteristicvalues.

–742–


⑥ Examinationofstabilityofsheetpileanchorage

(a)Whenthesheetpileanchoragebelowthetiememberinstallationpointislongenoughtoberegardedasalongpile,thecrosssectionofthesheetpileanchoragemaybedeterminedinaccordancewith③ Examination of stability of vertical pile anchorageabove.

(b)Sheetpilesanchoragethatcannotberegardedasalongpilemaybeverifiedinaccordancewith② Examination of stability of slab anchorageaboveontheassumptionthattheearthpressureactsonarangedowntom1/2pointbelowthetiememberinstallationpoint,asshowninFig. 2.3.30.Thelengthm1istheverticaldistancefromthetiememberinstallationpointtothefirstzeropointoftheflexuralmomentofsheetpilesassumingthatthesheetpileanchorageisalongpile.

Fig. 2.3.20 Virtual Earth Pressure for Short Sheet Pile Anchorage

(10) VerificationofGroundMotionsbyDynamicAnalysisMethods

① Forperformanceverificationofsheetpilequaywallsforgroundmotionsbydynamicanalysismethods,referto(9) Performance Verification for Ground Motions(detailed methods)in2.2 Gravity-type Quaywalls,2.2.3 Performance Verification. However,forsheetpilequaywallsthestressdistributioninthesoilvariesdependingontheconstructionprocess,soitisnecessarytoselectananalysismethodcapableofreproducingthestressdistributioninthesoilbeforetheearthquake.

② FortheaccidentalsituationsinrespectofLevel2earthquakegroundmotion,thestandardlimitvalueswhencarryingouttheperformanceverificationfortheamountofdeformationmaybeappropriatelycalculatedbyreferenceto1.4 Standard Concept of Allowable Deformation of High Earthquake-resistance Facilities for Level 2 earthquake ground motion.

(11) PerformanceVerificationofSuperstructures

① Superstructuremaybeverifiedasacantileverbeamthatisfixedatthetopofthesheetpileandsubjectedtotheearthpressureasanaction.However,itisnecessarytoconsiderthetractiveforcesofshipsandtheactiveearthpressurebehindthewallforthepartsonwhichbollardsareinstalledandthefenderreactionforceandthepassiveearthpressurebehindthewallforthepartsonwhichfendersareinstalled.Theonlyfactorthatshouldbeconsideredwithregardtoconditionsduringanearthquakeistheactiveearthpressure.

② ThetractiveforcesofshipsandfenderreactionsmaybeappliedasshowninFig. 2.3.21assumedtobeactingoverawidthbofthesuperstructureasshowninFig. 2.3.21(b).Inthiscase,normallywhenconsideringthetractiveforces,asurchargeshallbeconsideredintheactiveearthpressurecalculation,andwhenapplyingthefenderreactionsthepassiveearthpressuresurchargeshallnotbeconsidered.Thewallsurfacefrictionanglemaybetakentobe15°foractiveearthpressureand0°forpassiveearthpressure.Fortractiveforcesofshipsandfenderreactions,refertoPart II, Chapter 8, 2 Actions Caused by Ships.


–743–

b=4l

(a)(a)

P P/b

(b)

Permanent states ofactive earth pressure

b : width of action of tractive force (m) l : tie member interval (m)P : tractive force of ship (N)

Fig. 2.3.21 Tractive Forces of Ships Acting on the Superstructure

2.3.5 Structural Details

(1) InstallationofSheetPiles,Ties,andWaling

①Walingisnormallyinstalledsandwichingtiemembers,andfixedtothesheetpilewithboltsorsimilar.Ifwalingisinstalledtotherearofthesheetpile,thecross-sectionofthefasteningboltscanbedeterminedfromequation(2.3.28). However,ifnotembeddedinthecoping,it isnecessarytoconsideracorrosionallowance. Inthefollowingequation,thesymbolγisthepartialfactorforthesubscript,andthesubscriptdindicatesthedesignvalue.

(2.3.28)where,

A :boltcross-sectionalarea(cm2) Ap :reactionattiememberinstallationpointobtainedfromtheabove2.3.4(3) Flexural Moment of

Sheet Piles and Reaction at Tie Member Installation Point(N/m) w :spacingofsheetpile fastened to thewaling(m),when installedatoneposition intermediate

betweentiemembers,equivalenttoahalfofthetiememberspacing n :numberofboltsatonelocation(No.) σy :tensileyieldstressofbolt(N/cm2) γa :structuralanalysisfactor

In the equation, all the partial factors except the structural analysis factormaybe taken to be 1.0. Ifintermediateboltsareused,thestructuralanalysisfactormaybetakentobe2.5forpermanentsituations,and1.67forvariablesituationsinrespectoftheLevel1earthquakegroundmotion.Also,equation(2.3.18)maybeusedtocalculatethedesignvalueofthetensileyieldstressofthesteelmaterial.

(2)TieMemberTiemembertensionforceobtainedin2.3.4 (5) ② Tension force of tie member mustbetransmittedsafelytotheanchoragework.Whenbendingstresscausedbythesettlementofbackfillsoilisanticipated,thisshouldbetakenintoconsideration.

(3)InstallationofAnchoragesandTieMembers

① Acontinuousbeamalongthefacelineofquaywallisusuallyconstructedontopoftheanchoragepiles,andthetiemembersareattachedtothebeam.Thisbeammaybeverifiedforperformanceasacontinuousbeamsubjectedtothetiemembertensionforceandthereactionforceofthepiles.

–744–


2.4 Cantilevered Sheet Pile QuaywallsPublic NoticePerformance Criteria of Sheet Pile Quaywalls

Article 502Inadditiontotheprovisionsintheprecedingparagraph,theperformancecriteriaofcantileveredsheetpilesshallbesuchthattheriskinwhichtheamountofdeformationofthetopofthepilemayexceedtheallowable limit of deformation is equal toor less than the threshold level under thepermanent actionsituationsinwhichthedominantactionisearthpressureandunderthevariableactionsituationinwhichthedominantactionsareLevel1earthquakegroundmotions,shipberthing,andtractionbyships.

[Technical Note]

2.4.1 Fundamentals of Performance Verification

(1)Theperformanceverificationmethodsdescribedhereapplytosheetpilewallsdrivenintosandysoilground,andarenotapplicabletocohesivesoilground.

(2)Anexampleof thesequenceofperformanceverificationofcantileveredsheetpilequaywalls isshowninFig. 2.4.1.


–745–

Verification of deformation of top of sheet pile by simple method

Verification of stresses in sheet pile wall

Determination of embedment length of sheet pile

Examination of circular slips failure, settlementPermanent situations

Examination of deformation by dynamic analysis, etc.

Accidental state in respect ofLevel 2 earthquake ground motion

Setting of design conditions

Determination of cross-sectional dimensions

Verification of structural members

*1

*2

*3

Assumption of cross-section dimensions

Evaluation of actions including seismic coefficient for verification

Verification of deformation and stresses by dynamic analysis

Performance verificationPerformance verificationPermanent situations, variable situations of Level 1

earthquake ground motion and action of ships

Permanent situations,variable situations of action of ships

Permanent situations, variable situations in respectof Level 1 earthquake ground motion and

action of ships

Variable situations in respect ofLevel 1 earthquake ground motion

*1:Evaluationoftheeffectofliquefactionisnotshown,soitisnecessarytoconsidertheseseparately.*2:Whennecessary,anexaminationoftheamountofdeformationbydynamicanalysiscanbecarriedoutfortheLevel1earthquakeground

motion. For high earthquake-resistance facilities, it is preferable that examination of the amount of deformation be carried out by dynamic

analysis.*3:VerificationinrespectofLevel2earthquakegroundmotioniscarriedoutforhighearthquake-resistancefacilities.

Fig. 2.4.1 Example of Sequence of Performance Verification for Cantilevered Sheet Pile Quaywalls

–746–


(3)Fig. 2.4.2showsanexampleofacross-sectionofacantileveredsheetpilequaywall.

H.W.L.

L.W.L.

Rubber fender

(Crest height of steel pipe pile)

Curbing Bollard

Original ground level

Pavement curb

Backfill rock

Steel pipe pile

Design water depth

Backfill soil

Apron

Fig. 2.4.2 Example of Cross-section of Cantilevered Sheet Pile Quaywall

2.4.2 Actions

(1)Forcesactingonacantileveredsheetpilewallcanreferto2.3 Sheet Pile Quaywalls.

(2)Wheretheseabedgroundisofsandysoil,avirtualbottomsurfaceisassumedattheelevationwherethesumoftheactiveearthpressureandresidualwaterpressureisequaltothepassiveearthpressure.Itisassumedthattheearthpressureandresidualwaterpressurewillactonthepartofcantileveredsheetpilewallabovesuchthevirtualbottomsurface,asillustratedinFig. 2.4.3.

L.W.L Residual water level

Sea bottom

Passive earth pressure

Active earth pressure +residual water pressure

Virtualbottom surface

Difference between(active earth pressure +residual water pressure)and (passive earth pressure)

Fig. 2.4.3 Determination of Virtual Bottom Surface

(3)Thecharacteristicvalueoftheseismiccoefficientforverificationusedintheperformanceverificationofcantileveredsheet piled quaywalls under the variable situations in respect of Level 1 earthquake groundmotion shall beappropriatelycalculated taking thestructuralcharacteristics intoaccount. Forconvenience, thecharacteristicvalueoftheseismiccoefficientforverificationofcantileveredsheetpiledquaywallsmaybecalculatedasthesheetpiledquaywallswithverticalpileanchorage,in2.3 Sheet Pile Quaywalls,2.3.2(9) Seismic Coefficient used in Performance Verification of Sheet Pile Quaywalls with Pile Anchorage for Variable Situations in respect of Level 1 earthquake ground motion.


–747–

2.4.3 Performance Verification

(1)PerformanceVerificationofSheetPileWalls

① Themaximumflexuralmoment in a sheet pilewall shall be calculated appropriately by using an analysismethodcorrespondingtothemechanicalbehaviorcharacteristicsofthewall.ThemaximumflexuralmomentinasheetpilewallisnormallycalculatedbythePHRImethodconcerningthelateralresistanceofpiles.

② Thelateralresistanceofpilecanbecalculatedinaccordancewith2.4.5[4] Estimation of Pile Behavior using Analytical Methods in this Part, Chapter 2, 2.4 Pile Foundations.

③Whensteelpipesareusedassheetpiles,thesecondarystressoftendevelopsinsteelpipesofasheetpilewallduetothedeformationofthesteelpipecrosssection(i.e.acircularcrosssectionisdeformedintoanellipticone)thatiscausedbytheearthandresidualwaterpressure.Cantileveredsheetpilewallsarethestructurestendtoexperiencelargedisplacement,andthereisariskaboutsuchwallsthatarelativelyhighsecondarystressmaydevelopintheareasaroundthepointwheretheflexuralmomentbecomesmaximum.Thelargerthediameterofthesteelpipe,thehigherthelevelofsecondarystressbecomes.Insuchacase,therefore,itispreferabletoperformexaminationofstrengthagainstthesecondarystress.Thesecondarystressofasteelpipeiscalculatedusingequation(2.4.1).

(2.4.1)where

σt :secondarystress(N/mm2) p :earthpressureandresidualwaterpressureactingonthesheetpilewall(kN/m2) D :diameterofpipe(mm) t :platethicknessofpipe(mm) α :coefficient

Thecoefficientα in theequationmaybedefinedbyreferencetoFig. 2.4.4, takingintoconsiderationthewidthofaction,foundationconditionsandconstraintconditions.Inthisfigure,“Sliding”and“Fixed”indicatethedisplacementconditionsofthejointsofthesteelpipepile,inaccordancewiththegroundconditionsandconstraintconditionsofthesheetpiling.

0.25

0.20

0.15

0.10

0.05

0.000 30 60 90 120 150 180

2θLoad

SlidingSliding

Width of action θ (˚)Width of action θ (˚)

FixedFixedCoe

ffic

ient

α

Fig. 2.4.4 Coefficientα

Verificationmaybecarriedoutusingthefollowingequation(2.4.2),basedontheaxialstressσlinthepileobtainedinaccordancewith5.2 Open-Type Wharves on Vertical Piles,andthesecondarystressσtobtainedfromequation(2.4.1).Inthefollowing,thesymbolγisthepartialfactorcorrespondingtothesubscript,andthesubscriptskanddindicatethecharacteristicvalueandthedesignvalue,respectively.Thestructuralanalysisfactormaybe taken tobe1.2 forpermanent situations,and1.0 forvariablesituations in respectofLevel1earthquakegroundmotion.

(2.4.2)

where, σl :stressduetoaxialforcesinthepile(N/mm2)

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σt :secondarystressduetobendingmomentinthepile(N/mm2) fyd :designyieldstressofthepile(N/mm2),fyd = fyk /γm fyk :yieldstressofpile(N/mm2) γm :materialcoefficient(=1.05) γb :membercoefficient(=1.1) γa :structuralanalysisfactor

Thedesignvaluesintheequationmaybecalculatedfromthefollowingequation.Also,thepartialfactorsmaybealltakentobe1.0.

(2.4.3)

(2)ExaminationofEmbeddedLengthsofSheetPilesTheembeddedlengthofsheetpilesshallbeequaltoorlongerthantheeffectivelengthofpilesthatiscalculatedinaccordancewith2.4.5 Static Maximum Lateral Resistance of PilesinPart II, Chapter 2, 2.4 Pile Foundations.Becauseacantileveredsheetpilewallretainstheearthbehindthewallinthemechanismsameaspilesdo,theembeddedlengthofthesheetpilemaybecalculatedinthesamewayasinthecaseofapile.InthePHRImethodforthelateralresistanceofpiles,therequiredembeddedlengthiscalculatedas1.5m1,wherem1representsthedepthoffirstzeropointoftheflexuralmomentofcantileveredpile.Itshouldbenotedthattheembeddedlengthcalculatedhere is thatmeasurednot from the seabottomsurface,but thatmeasured from thevirtualbottomsurface.


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2.5 Sheet Pile Quaywalls with Raking Pile Anchorages2.5.1 Fundamentals of Performance Verification

(1)Thefollowingisapplicabletotheperformanceverificationofmooringfacilitiesinwhichrakingpilesaredrivenbehindthesheetpilewall,andthetopsofthesheetpilewallandtherakingpilesareconnectedtosupportthesoilbehindthesheetpilewall.

(2)AnexampleofthesequenceofperformanceverificationofsheetpiledquaywallswithrakingpileanchoragesisshowninFig. 2.5.1.

(3)Anexampleofacross-sectionofsheetpilequaywallswithrakingpileanchoragesisshowninFig. 2.5.2.

Verification of stresses in sheet pile and raking anchorage piles

Verification of bearing capacity of raking piles


Verification of circular slip failurePermanent situations

Examination of amount of deformation by dynamic analysis

Accidental state in respect of Level 2 earthquake ground motion


Determine cross-sectional dimensions


*1

*2

*3

Assumption of cross-sectional dimensions


Verification of deformation and stresses by dynamic analysis

Performance verificationPerformance verificationPermanent situations, variable situations in respect

of Level 1 earthquake ground motion

Permanent situations, variable situations in respectof Level 1 earthquake ground motion

and action of ships

Permanent situations, variable situations in respectof Level 1 earthquake ground motion

and action of ships

Variable situations in respect of Level 1 earthquake ground motion

*1:Theevaluationoftheeffectofliquefactionisnotshown,itisnecessarytoconsidertheseseparately.*2:Whennecessary,anexaminationoftheamountofdeformationbydynamicanalysiscanbecarriedoutfortheLevel1earthquakeground

motion. Forhighearthquake-resistancefacilities,itispreferablethattheexaminationoftheamountofdeformationbecarriedoutbydynamic analysis.*3:VerificationinrespectofLevel2earthquakegroundmotioniscarriedoutforhighearthquake-presistancefacilities.

Fig 2.5.1 Example of Sequence of Performance Verification of Sheet Pile Quaywalls with Raking Pile Anchorages

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Sheet pile Raking anchorage pile

L.W.L.H.W.L.

Fig. 2.5.2 Example of Cross-section of Sheet Pile Quaywall with Raking Pile Anchorage

2.5.2 Actions

(1)Fortheactiononsheetpiledwallswithrakingpileanchorages,referto2.3 Sheet Pile Quaywalls.

(2)ThecharacteristicvalueoftheseismiccoefficientforverificationusedinperformanceverificationofsheetpilequaywallswithrakingpileanchoragesforthevariablesituationsinrespectofLevel1earthquakegroundmotionshallbeappropriatelycalculated taking thestructuralcharacteristics intoconsideration. Forconvenience, thecharacteristicvalueoftheseismiccoefficientforverificationofsheetpilequaywallswithrakingpileanchoragesmaybecalculatedasthesheetpilequaywallsverticalpileanchorage, in2.3.2(9) Seismic Coefficient used in Performance Verification of Sheet Pile Quaywalls with Pile Anchorage for Variable Situations in respect of Level 1 earthquake ground motion.


(2)VerificationofStressesinSheetPileandRakingAnchoragePiles

① Forsheetpilequaywallswithrakingpileanchorages,verificationmaybecarriedoutfortheresistanceofthesheetpileandthepiles,againsttheactionsinthehorizontalandverticaldirectionattheconnectionpoint,earthpressureandresidualwaterpressure.

② Thehorizontalandverticalforcesactingontheconnectionpointbetweenasheetpileandarakingpilecanbecalculatedbyassumingthattheconnectionisapinstructure.

(3)DeterminationofEmbeddedLengthsofSheetPileandRakingPileTheembeddedlengthofthesheetpileorrakinganchoragepilethatisrequiredtoresisttheforcesactingintheaxialdirectionaswellasthedirectionperpendiculartotheaxiscanbecalculatedinaccordancewithPart II, Chapter, 2.4 Pile Foundations.However,itispreferabletoexaminethebearingcapacityintheaxialdirectionofthesheetpileandthatoftherakinganchoragepilethroughloadingandpullingtests.

2.5.4 Performance Verification of Structural Members

Performanceverificationofsheetpiledquaywallswithrakingpileanchoragescanapplythatofsheetpiledquaywallsandopentypewharvesonverticalpiles.Referto2.3.4 Performance Verifi cation,and5.2.5 Performance Verification of Structural Members.


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2.6 Open-type Quaywall with Sheet Pile Wall Anchored by Forward Batter Piles2.6.1 Fundamentals of Performance Verification

(1)Theprovisionsinthissectionshallbeappliedtotheperformanceverificationofsheetpilequaywallsthatarebuiltbycouplingthesheetpileheadswiththerakinganchoragepilesdriveninthegroundinfrontofthesheetpilesthatretaintheearthintheback.

(2)Open-typequaywallwith sheetpilewall anchoredby forewardbatterpiles arenormallyconstructedwith anopen–typewharfbuiltinfrontofthesheetpilewall.Theopen–typewharfmayormaynotbeintegratedintothesheetpilewall,butthissectionprovidesguidelinesforthecasesinwhichtheopen–typewharfandsheetpilewallareintegrated.Forthecasesinwhichtheopen–typewharfisnotintegratedintothesheetpilewall,referto2.3 Sheet Pile Quaywalls,5.2 Open–Type Wharves on Vertical Piles,and5.3 Open–Type Wharves on Coupled Raking Piles.Theperformanceverificationmethoddescribedinthissectionisbasedonthesheetpileperformanceverificationwiththeequivalentbeammethod.Therefore,thestructuraltypescoveredbythissectionaresteelsheetpilewallsdrivenintoasandysoilgroundorahardclayeysoilground.

(3)AnexampleofthesequenceofperformanceverificationofOpen-typeQuaywallwithSheetPileWallAnchoredbyForwardBatterPilesisshowninFig. 2.6.1.

(4)Here,amethodofcarryingouttheperformanceverificationofthesheetpilesandtheperformanceverificationof theotherpiles in threestages isdescribed,asamethodofsimpleverification. Performanceverificationofthesheetpilescanbecarriedoutinaccordancewiththemethodsofperformanceverificationofsheetpile,byconsidering the connectionpoints between the raking support piles and the sheet pile to be fulcrums. Next,thereactionat theconnectionpointsbetweentherakingsupportpilesandthesheetpile isconsidered tobeahorizontalforceactingonthepiledpiersuperstructure,andtheaxialforcesactinginthesheetpileandthepilesarecalculatedinaccordancewiththeperformanceverificationofopentypewharvesonrakingpiles.Then,thesheetpileandtherakingsupportpilesareconsideredtobearigidframestructurefixedatavirtualfixingpoint,andthemomentsinthetopconnectionpointsduetoearthpressureandotherhorizontalforcesarecalculated.

(5)Anexampleofcross-sectionofopen-typequaywallwithsheetpilewallanchoredbyforwardbatterpilesisshowninFig. 2.6.2.

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Verification of circular slip failurePermanent situations




*1

*2

*3

Assumption of cross-sectional dimensions


Performance verificationPerformance verificationPermanent situations, variable situations in respect

of Level 1 earthquake ground motion

Variable situations in respect of action of ships,surcharge, and Level 1 earthquake ground motion

Variable situations in respect ofLevel 1 earthquake ground motion

Accidental state in respect of Level 2 earthquake ground motion

Verification of stresses in piles

Verification of bearing capacity of piles



Examination of amount of deformation by dynamic analysis

Verification of deformation andpiled pier damage by dynamic analysis


*1:Theevaluationoftheeffectofliquefactionisnotshown,itisnecessarytoconsidertheseseparately.*2:Whennecessary,anexaminationoftheamountofdeformationbydynamicanalysiscanbecarriedoutfortheLevel1earthquakeground

motion. Forhighearthquake-resistancefacilities,itispreferablethattheexaminationoftheamountofdeformationbecarriedoutbydynamic analysis.*3:VerificationinrespectofLevel2earthquakegroundmotioniscarriedoutforhighearthquake-resistancefacilities.

Fig. 2.6.1 Example of Sequence of Performance Verification ofOpen-type Quaywall with Sheet Pile Wall Anchored by Forward Batter Piles


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Bollard

Fenders

Backfill rocks

Steel pipe pile

Steel sheet pipe pile

Steel pipe pile

Design water depth

Fig. 2.6.2 Example of Cross-section of Open-type Quaywall with Sheet Pile Wall Anchored by Forward Batter Piles

2.6.2 Actions

(1)Fortheactiononthepiledpierpart,referto5.2 Open-Type Wharves on Vertical Piles.

(2)Fortheactionofthesheetpile,referto2.3 Sheet Pile Quaywalls.

(3)Theselfweightofreinforcedconcreteof thesuperstructureofopen–typewharfcanbecalculatedwithaunitweightof21kN/m2intheperformanceverificationoftheverticalandrakingpilesandsheetpilesinaccordancewith5.3 Open-Type Wharves on Coupled Raking Piles.

(4)Thefenderreactionforcecanbecalculatedusingcalculationmethodsdescribedin5.2 Open-Type Wharves on Vertical Piles.

(5)Thecharacteristicvalueoftheseismiccoefficientforverificationusedinperformanceverificationofopen-typequaywallwithsheetpilewallanchoredbyforewardbatterpilesforthevariablesituationsinrespectofLevel1earthquakegroundmotionshallbeappropriatelycalculatedtakingthestructuralcharacteristicsintoconsideration.Forconvenience,thecharacteristicvalueoftheseismiccoefficientforverificationusedinperformanceverificationofopen-typequaywallwithsheetpilewallanchoredbyforewardbatterpilesmaybecalculatedinaccordancewith5.2 Open Type Wharf on Vertical Piles, 5.2.3(10) Ground Motion used in Performance Verification of Seismic–resistant.

2.6.3 Layout and Dimensions

(1)Refertothesizeofdeckblockandlayoutofpilesdescribedin 5.2 Open-Type Wharves on Vertical Piles forthesizeofoneblockofthesuperstructureandlayoutofpiles.

(2)Itispreferablethatlayoutandinclinationoftherakingpilesaredeterminedinconsiderationoftheirpositionalrelationshipwithotherpilesandconstructionwork–relatedconstraintssuchasthoseconcerningthecapacityofpiledrivingequipment.Apileinclinationofabout20ºisnormallyusedforrakingpiles.

(3)Forthedimensionsofthesuperstructure,refertodimensionsofsuperstructurein5.2 Open-Type Wharves on Vertical Piles.


(1)Performanceverificationofthesheetpilewallmaybecarriedoutconsideringtheconnectionpointbetweentherakingsupportpileandthesheetpileasfulcrums.Referto2.3 Sheet Pile Quaywalls.

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(2)Fortheearthpressureandresidualwaterpressureactingonthesheetpile,theconnectionpointbetweentherakingsupportpileandthesheetpilemaybeconsideredtobeafulcrumreaction.

(3)If it is necessary to carry out verification of rotation of the piled pier block, this shall be appropriatelyconsidered.

(4)PerformanceVerificationofthePiledPierPart

① Fortheperformanceverificationofthepiledpierpart,referto5.2 Open-type Wharves on Vertical Piles,and5.3 Open-type Wharves on Coupled Raking Piles.

② Forassumptionsregardingtheseabed,refertoassumptionsregardingtheseabedin5.2 Open–type Wharves on Vertical Piles.Forthehorizontalresistanceofpiles,estimationofthebehaviorofthepilesmaybecarriedoutusingthemethodofY.L.Chang.

③ The vertical loads distributed to the pile heads can be calculated as the fulcrum reaction forces under theassumptionthatthesuperstructureofopen–typewharfisasimplebeamsupportedatthepositionsofpileheads.Theaxialforcesontherakingpileandsheetpileshouldbecalculatedaccordingtoequation(2.4.60)in2.4.5[6] Lateral Bearing Capacity of Coupled PilesinPart III,Chapter 2, 2.4 Pile Foundations usingthehorizontalforceonthequaywallandtheverticalloaddistributedtopileheads.Fortheaxialforceofaverticalpile,theverticalloaddistributedtothepileheadmaybeused.

④ Theflexuralmomentattheconnectionoftherakingpileandthesheetpilemaybecalculatedasthemomentduetotheearthpressure,residualwaterpressureandotherhorizontalforces,byassumingthattherakingandsheetpilesconstitutearigidframefixedatthevirtualfixedpoint.

(5)Examinationofembeddedlengthwithrespecttotheaxialforce,andexaminationoftheembeddedlengthwithrespecttothelateralresistancecanbemadeinaccordancewith5.2 Open-type Wharves on Vertical Piles.

2.6.5 Performance Verification of Structural Members

(1)Theperformanceverificationforstructuralmembersofsheetpilewallanchoredbyforwordbatterpilescanbemadebyreferringtotheprovisionsin2.3 Sheet Pile Quaywalls and5.2 Open-type Wharves on Vertical Piles.

(2)Theconnectingpointofthesheetpilewallandrakingpileneedtobestructuredsothattheloadtransmissionfunctionsadequately.

(3)The superstructure of open–type wharf shall be structured so that it fully withstands the flexural momenttransmittedfromthesheetpilewall.

(4)Theconnectingpointbetween thesheetpilewallandrakingpilemusthavesufficient reinforcement,becausebreakageordamageattheconnectingpointcouldleadtothecollapseoftheentirequaywall.Theflexuralmomentgeneratedintheheadofthesheetpileistransmittedtothesuperstructureofopen–typewharf.Therefore,thisflexuralmomentneedtobetakenintoconsiderationintheperformanceverificationofthesuperstructure.


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2.7 Double Sheet Pile QuaywallsPublic NoticePerformance Criteria of Double Sheet Pile Quaywalls

Article 503Inadditiontotheprovisionsinthefirstparagraph,theperformancecriteriaofdoublesheetpilestructuresshallbeasspecifiedinthesubsequentitems(1)Theriskofoccurrenceofslidingofthestructuralbodyshallbeequaltoorlessthanthethresholdlevel

underthepermanentactionsituationsinwhichthedominantactionisearthpressureandunderthevariableactionsituationinwhichthedominantactionisLevel1earthquakegroundmotions.

(2)Theriskthatthedeformationofthetopofthefrontorrearsheetpilemayexceedtheallowablelimitofdeformationshallbeequaltoorlessthanthethresholdlevelunderthepermanentactionsituationinwhich thedominantaction isearthpressureandunder thevariableactionsituation inwhich thedominantactionisLevel1earthquakegroundmotions.

(3)Theriskoflosingthestabilityduetosheardeformationofthestructuralbodyshallbeequaltoorlessthanthe threshold levelunder thepermanentactionsituationinwhichthedominantactionisearthpressure.

[Technical Note]

2.7.1 Fundamentals of Performance Verification

(1)Thefollowingisapplicabletotheperformanceverificationofmooringfacilitiesthatuseadoublesheetpilestructure.

(2)Adoublesheetpilequaywallisamooringfacilityinwhichtworowsofsheetpilewallsaredrivenandconnectedbytiemembersorsimilar,thenthespacebetweenthetwowallsisbackfilledwithsoilsothatanearthretainingstructureisformed.

(3)Anexampleofthecross-sectionofadoublesheetpilequaywallisshowninFig. 2.7.1.(4)AnexampleofthesequenceofperformanceverificationofdoublesheetpilequaywallsisshowninFig.

2.7.2.

Waling

Paint coatingSteel pipe sheet pile

Design water depth

Quaywall face line

Apron

Sand filling

Replacement sand

High tensile steel tie rod

Waling

Filling

Steel pipe sheet pile

Fig. 2.7.1 Example of the Cross-section of a Double Sheet Pile Quaywall

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Analysis of the amount of deformation by dynamic analysis


Permanent situations, variable situations ofLevel 1 earthquake ground motion

Permanent situations, and variable situations of Level 1 earthquake ground motion

and action of ships

Permanent situations, and variable situations of Level 1 earthquake ground motion

Variable situations of Level 1earthquake ground motion

Accidental states of Level 2earthquake ground motion

Permanent situation



Verification of circular slip failure and settlementPermanent situations

Permanent situation, and variable situation of Level 1 earthquake ground motion

Provisional assumption of cross-sectional dimensions

Evaluation of actionsPerformance verificationPerformance verification

*1

*2

*3

Verification of shear deformation of double sheet pile wall structure



Verification of stresses in tie members

Verification of stresses in waling

Verification of sliding of double sheet pile wall structure

*1:Theevaluationoftheeffectofliquefactionisnotshown,sothismustbeseparatelyconsidered.*2:AnalysisoftheamountofdeformationduetoLevel1earthquakegroundmotionmaybecarriedoutbydynamicanalysiswhennecessary. Forhighearthquake-resistancefacilities,analysisoftheamountofdeformationbydynamicanalysisisdesirable.*3:Forhighearthquake-resistancefacilities,verificationiscarriedoutforLevel2earthquakegroundmotion.

Fig. 2.7.2 Example of the Sequence of Performance Verification of Double Sheet Pile Quaywalls


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(5)Intheperformanceverificationofdoublesheetpilequaywalls,theperformanceverificationmethodsforsteelsheetpilecellular-bulkheadquaywallsorsheetpilequaywallswithsheetpileanchoragehaveconventionallybeenapplied.Therefore,whenverifyingtheperformanceofadoublesheetpilequaywallwiththeconditionsthataresimilartothoseusedinexistingquaywalls,performanceverificationmethodsdescribedinthissectionmaybeused.

2.7.2 Actions

(1)For the action on double sheet pile quaywalls, refer to 2.9 Cellular-bulkhead Quaywalls with Embedded Sections.

(2)ThecharacteristicvalueoftheseismiccoefficientforverificationusedinperformanceverificationofdoublesheetpilequaywallsforthevariablesituationsofLevel1earthquakegroundmotionshallbeappropriatelycalculatedtakingintoconsiderationthestructuralcharacteristics.Forconvenience,thecharacteristicvalueoftheseismiccoefficientforverificationofdoublesheetpilequaywallsmaybecalculatedinaccordancewiththatforanchoredverticalpile typesheetpiledquaywalls, in2.3.2(9) Performance Verification of Anchorages for Sheet Pile Quaywalls on Variable Situation in respect of Level 1 Earthquake Ground Motion.


(1)Theexaminationtodeterminethewidthbetweentwosheetpilewallstoachievetherequiredstrengthagainstsheardeformationcanbemadeinaccordancewith2.9 Cellular-bulkhead Quaywalls with Embedded Sections.

(2)Thecalculationofthedeformationmomentcanbemadeinaccordancewith2.9 Cellular-bulkhead Quaywalls with Embedded Sections.

(3)Thecalculationof theresistancemomentcanbemadeinaccordancewith2.9 Cellular-bulkhead Quaywalls with Embedded Sections.However,theresistancemomentduetothefrictionsatthejointsbetweensheetpilesofthepartitionwallsisnotconsiderednormally.

(4)Theembeddedlengthofsheetpilesisdeterminedasthelongeroneofeitherthatcalculatedbythemethodforsheetpileshavingordinaryanchoragereferringtoexaminationofembeddedlengthsofsheetpilesin2.3 Sheet Pile Quaywallsorthatsatisfyingtheallowablelimitforhorizontaldisplacementrequirementreferringtoexaminationof stability ofwall body as awhole and examination of displacement ofwall top in2.9 Cellular-bulkhead Quaywalls with Embedded Sections

(5)Adouble sheetpilequaywall canbeconsideredasakindofgravitywall. Thus it isnecessary toverify thestabilityagainstslidingofthequaywallandtheoverallslopestabilityincludingthewallstructure,asinthecaseofacellular-bulkheadtypequaywall.Intheperformanceverificationreferencecanbemadeinaccordancewiththeperformanceverificationdescribedin2.2 Gravity-type Quaywalls.Slidingisusuallyexaminedeitheratthevirtualbottomsurfacewhichistakenattheseabottomorthehorizontalplaneatthetoeofthesheetpilewall.Intheformercase,theresistanceofthesheetpilewallbelowtheseabottomshouldbeignored.Intheexaminationoftheoverallslopestabilityincludingthedoublesheetpilequaywall,theembeddedlengthofthedoublesheetpilequaywallmustbecomparedwiththerequiredembeddedlengthcalculatedforacorrespondingsinglesheetpilequaywallwithanchorage.Iftheformerisfoundlongerthanthelatter,theresistanceoftheportionofsheetpilesbelowthecalculatedtoeofthelattersheetpilesshouldbeignoredagainstthecircularslipplanepassingthelevelbelowthetoe.

(6)Performanceverificationoftheslabanduprightsectionofthesuperstructurecanbemadeinaccordancewiththeperformanceverificationofrelievingplatformin2.8 Quaywalls with Relieving Platforms.Foundationpilesaresometimesdrivenintothefillingmaterialtosupportthesuperstructure.Thesepilesshouldhavesufficientsafetyagainstthehorizontalandverticalforcestransmittedfromthesuperstructure.Hereitisassumedthattheverticalforcetransmittedfromthesuperstructureisentirelybornebythepiles,andtheverticalbearingcapacityofthepileiscalculatedbyignoringtheskinfrictionbetweenthepileandthefillingmaterial.Thehorizontalforcethatactsonthesuperstructureistransmittedtothedoublesheetpilequaywallpartlythroughthepilesandpartlythroughthesheetpiles.Thereforeitisnecessarytodetermineappropriateburdenshearingofthehorizontalforcebythetwosections.

(7)Whendoublesheetpiledwallstructuresareused,theamountofdeformationmaybeevaluatedbyastaticmethodusingSawaguchi’smethod72)orOhori’smethod.73)

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2.8 Quaywalls with Relieving PlatformsPublic NoticePerformance Criteria of Quaywalls with Relieving Platforms

Article 51 The performance criteria of quaywallswith relieving platforms shall be as specified in the subsequentitems:(1)Sheetpilesshallhavetheembedmentlengthasnecessaryforstructuralstabilityandcontainthedegree

ofriskthatthestressesinthesheetpilesmayexceedtheyieldstressatthelevelequaltoorlessthanthethresholdlevelunderthepermanentactionsituationinwhichthedominantactionisearthpressureandunderthevariableactionsituationinwhichthedominantactionisLevel1earthquakegroundmotions.

(2)TheriskofoccurrenceofslidingoroverturningtothestructuralbodyshallbeequaltoorlessthanthethresholdlevelunderthepermanentactionsituationinwhichthedominantactionisearthpressureandunderthevariableactionsituationinwhichthedominantactionisLevel1earthquakegroundmotions.

(3)Thefollowingcriteriashallbesatisfiedunderthepermanentactionsituationinwhichthedominantactionisselfweight:(a)Theriskthattheaxialforcesactingintherelievingplatformpilesmayexceedtheresistanceforce

basedonfailureofthesoilsshallbeequaltoorlessthanthethresholdlevel.(b)Theriskofimpairingtheintegrityofthemembersoftherelievingplatformshallbeequaltoorless

thanthethresholdlevel.(4)Thefollowingcriteriashallbesatisfiedunderthepermanentactionsituationinwhichthedominant

actionisearthpressureandunderthevariableactionsituationinwhichthedominantactionsareLevel1earthquakegroundmotions,shipberthing,andtractionbyships:(a)Theriskthattheaxialforcesactingontherelievingplatformpilesmayexceedtheresistanceforce

basedonfailureofthesoilsshallbeequaltoorlessthanthethresholdlevel.(b)Theriskthatthestressactingontherelievingplatformpilesmayexceedtheyieldstressshallbe

equaltoorlessthanthethresholdlevel.(c)Theriskofimpairingtheintegrityofthemembersoftherelievingplatformshallbeequaltoorless

thanthethresholdlevel.(5)Theriskofoccurrenceofaslipfailureinthegroundthatpassesbelowthebottomendofthesheet

pilingshallbeequaltoorlessthanthethresholdlevelunderthepermanentactionsituationinwhichthedominantactionisselfweight.

[Commentary]

(1)PerformanceCriteriaofQuaywallswithRelievingPlatforms①Theperformancecriteriaofquaywallswithrelievingplatformsshallusethefollowinginaccordance

withthedesignsituationsandthestructuremembers. Besidestheserequirements,whennecessarythesettingsofthePublic Notice Article 22 Paragraph 3(ScouringandWashingOut)shallbeapplied.

②SheetpileandStructuralStability(a)The setting for sheet pile and structural stability of the performance criteria of quaywallswith

relievingplatformsandthedesignsituationsexcludingaccidentalsituationsshallbeinaccordancewithAttached Table 37.


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Attached Table 37 Setting for the Performance Criteria of Sheet Pile and Structural Stability of Quaywalls with Relieving Platforms and the Design Situations excluding Accidental Situations

MinisterialOrdinance PublicNotice

Performancerequirements

Designsituation

Verificationitem Indexofstandardlimitvalue

Article

Paragraph

Item

Article

Paragraph

Item Situation Dominating

actionNon–

dominatingaction

26 1 2 51 1 1 Serviceability Permanent Earthpressure Waterpressure,surcharges

Necessaryembedmentlength

Systemfailureprobabilityunderpermanentsituationsofselfweightandearthpressure(Highearthquake-resistancefacilityPf=1.7×10–3)(Otherthanhighearthquake-resistancefacilityPf=4.0×10–3)

Yieldingofsheetpile

Variable L1earthquakegroundmotion

Earthpressure,waterpressure,surcharges

Necessaryembedmentlength

Allowableamountofdeformationoftopofquaywall:applysheetpilequaywallsYieldingofsheetpiling

2 Permanent Earthpressure Selfweight,waterpressure,surcharge

Sliding/overturningofwallstructure

Systemfailureprobabilityunderpermanentsituationsofselfweightandearthpressure(Highearthquake-resistancefacilityPf=1.7×10–3)(Otherthanhighearthquake-resistancefacilityPf=4.0×10–3)


Selfweightearthpressure,waterpressure,surcharge

Sliding/overturningofwallstructure

LimitvalueforslidingLimitvalueforoverturning(Allowableamountofdeformationoftopofquaywall:applygravity-typequaywalls)

5 Permanent Selfweight Waterpressure,surcharge

Circularslipfailureofground

Systemfailureprobabilityunderpermanentsituationsofselfweightandearthpressure(Highearthquake-resistancefacilityPf=1.7×10–3)(Otherthanhighearthquake-resistancefacilityPf =4.0×10–3)

(b)PerformancecriteriaofsheetpileOfthesettingsfortheperformancecriteriaforrelievingplatformquaywallsandthedesignsituations,thoseapplicabletothesheetpileshallcomplywiththesettingsinaccordancewiththePublic Notice Article 50 Paragraph 1(PerformanceCriteriaforSheetPiledQuaywalls).

(c)PerformanceCriteriaofWallStructuresIntheverificationofthestabilityofthestructureofquaywallswithrelievingplatforms,thewallstructureisequivalenttothewallstructureinthecaseofagravity-typequaywall.ThewallstructureshallcomplywiththesettingofthePublic Notice Article 49(PerformanceCriteriaofGravity-typeQuaywalls).

(d)PerformanceCriteriaofCircularSlipsintheGroundThe setting for circular slips in the ground shall complywith the settings of thePublic Notice Article 50 Paragraph 1(PerformanceCriteriaofSheetPileQuaywalls).

③RelievingPlatformandRelievingPlatformPiles(a) Thesettings for relievingplatformsand relievingplatformpilesshallbeasshown inAttached

Table 38.

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Attached Table 38 Settings for the Performance Criteria for the Relieving Platform and Relieving Platform Piles of Quaywalls with Relieving Platforms and the Design situations excluding Accidental Situations

MinisterialOrdinance PublicNotice

Performancerequirements

Designsituation

Verificationitem Indexofstandardlimitvalue

Article

Paragraph

Item

Article

Paragraph

Item Situation Dominating

actionNon–

dominatingaction

26 1 2 51 1 3a Serviceability Permanent Selfweight Surcharging,waterpressure

Axialforcesonrelievingplatformpiles

Resistancecapacitybasedonfailureoftheground(pushing,pulling)

3b Earthpressure,waterpressure,surcharge

Serviceabilityofcross-sectionofrelievingplatform

Limitvalueofbendingcompressivestress(serviceabilitylimitstate)

4a Variable Earthpressure Selfweight,waterpressure,surcharge

Axialforcesactingontherelievingplatformpiles

Resistancecapacitybasedonfailureoftheground(pushing,pulling)

L1earthquakegroundmotion

Selfweight,earthpressure,waterpressure,surcharge

Tractionofships

4b Permanent Earthpressure Waterpressure,surcharge

Yieldingofrelievingplatform

Designyieldstress


Selfweight,earthpressure,waterpressure,surchargeTractionof

ships4c Permanent Earthpressure Waterpressure,

surchargeServiceabilityofcross-sectionofrelievingplatform

Limitingvalueofbendingcompressivestress(serviceabilitylimitstate)


Selfweight,earthpressure,waterpressure,surcharge

Failureofcross-sectionofrelievingplatform

Designcross-sectionalresistanceforce(ultimatelimitstate)

Tractionofships

(b)AxialForcesActingontheRelievingPlatformPilesVerificationoftheaxialforcesactingontherelievingplatformpilesistoverifytheriskthattheaxialforcesactingontherelievingplatformpileswillexceedtheresistanceforcebasedonfailureofthegroundisequaltoorlessthanthelimitingvalue.

(c)YieldingofRelievingPlatformPilesVerificationofyieldingintherelievingplatformpilesistoverifytheriskthatthestressesactingontherelievingplatformpileswillexceedtheyieldstressisequaltoorlessthanthelimitingvalue.

(d)ServiceabilityoftheCross-sectionoftheRelievingPlatformVerificationofserviceabilityoftherelievingplatformistoverifytheriskthatthedesignbendingcompressivestressesintherelievingplatformwillexceedthelimitingvalueofcompressivestressisequaltoorlessthanthelimitingvalue.

(e)Cross-sectionalFailureoftheRelievingPlatformVerificationofcross-sectionalfailureoftherelievingplatformistoverifytheriskthatthedesigncross-sectionalforcesintherelievingplatformwillexceedthedesigncross-sectionalresistanceisequaltoorlessthanthelimitingvalue.

[Technical Note]

2.8.1 Principles of Performance Verification

(1)Theprovisionsinthischaptermaybeappliedtotheperformanceverificationofquaywallwithrelievingplatformthatcomprisesarelievingplatform,asheetpilewallinfrontoftherelievingplatform,andrelievingplatformpiles.

(2)Sheetpilequaywallwitharelievingplatformnormallycomprisearelievingplatform,asheetpilewallinfrontof the relieving platform, and relieving platform piles. The relieving platform is inmany cases constructedasanL-shapedstructureofcast-in-placereinforcedconcreteandisusuallyburiedunderlandfillmaterial,butsometimesaboxshapeplatformisusedtoreducetheweightoftheplatformandtheearthquakeforcesthatactonitseeFig. 2.8.1 and2.8.2.


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(3)Theperformanceverificationofaquaywallwitharelievingplatformcanbemadeseparatelyforthesheetpiles,therelievingplatform,andtherelievingplatformpiles.

Sheet pile wall

Relieving platform

Relieving platform piles

W.L.

Fig. 2.8.1 Structure of Quaywall with Relieving Platform (L-Shaped Platform)

W.L.

Relieving platform

Void

Fig. 2.8.2 Structure of Quaywall with Relieving Platform (Box Shape Platform)

(4)AnexampleofthesequenceofperformanceverificationofaquaywallwithrelievingplatformisshowninFig. 2.8.3.

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Permanent situation, variable situations of Level 1 earthquake ground motion

Permanent situation

Permanent situation, and variable situations of Level 1 earthquake ground motion

and action of ships

Accidental situations of Level 2 earthquake ground motion


Verification of structural members (verification of relieving platform, etc.)

Permanent situation

Permanent situation, and variable situations of Level 1 earthquake ground motion

Variable situations of Level 1 earthquake ground motion


Provisional assumption of cross-sectional dimensions

Performance verificationPerformance verification

*1

*2

*3


Analysis of stresses in sheet pile wall

Determination of dimensions of sheet pile

Provisional layout of relieving platform

Verification of axial forces on relieving platform piles

Verification of stresses in relieving platform piles

Verification of sliding and overturning as a gravity wall

Analysis of the amount of deformation by dynamic analysis

Verification of deformation and stress by dynamic analysis

Verification of circular slips failure and settlement

*1:Theevaluationoftheeffectofliquefactionisnotshown,sothismustbeseparatelyconsidered.*2:AnalysisoftheamountofdeformationduetoLevel1earthquakegroundmotionmaybecarriedoutbydynamicanalysiswhennecessary. Forhighearthquake-resistancefacilities,analysisoftheamountofdeformationbydynamicanalysisisdesirable.*3:Forhighearthquake-resistancefacilities,verificationiscarriedoutforLevel2earthquakegroundmotion.

Fig. 2.8.3 Example of the Sequence of Performance Verification of a Quaywall with Relieving Platform


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2.8.2 Actions

(1)The earth pressure and residual water pressure acting on sheet piles vary greatly according to structuralcharacteristics.Therefore,theyshallbecalculatedappropriatelyinconsiderationoftheheightandwidthoftherelievingplatformaswellassupportconditions.

(2)When the active failure surface of backfill soil from the intersection between the sea bottomand sheet pilesintersectstherelievingplatform,theactiveearthpressureactingonthesheetpilewallcanbecalculatedontheassumptionthatthebottomoftherelievingplatformisthevirtualgroundsurfaceandnosurchargeisonitasshowninFig. 2.8.4.

(3)Theresidualwaterpressureactingonthesheetpilewallshouldbeconsideredthesameasthatofthecasewithoutarelievingplatform.Theforcetobeadoptedshouldbetheresidualwaterpressureactingontherangebelowthebottomlevelofrelievingplatform,seeFig. 2.8.4.

(4)Asforpassiveearthpressureinfrontoftheembeddedsectionofsheetpile,2.3 Sheet Pile Quaywallscanbereferred.

Design water level(L.W.L) Residual water level

Passiveearth pressure

Activeearth pressure

Res

idua

l wat

er p

ress

ure

Fig. 2.8.4 Earth Pressure and Residual Water Pressure Acting on Sheet Pile Wall

(5)ThecharacteristicvalueofseismiccoefficientforverificationusedintheperformanceverificationofquaywallswithrelievingplatformsforthevariablesituationsassociatedwithLevel1earthquakegroundmotionshallbecalculatedtakingthestructuralcharacteristicsintoconsideration.Forconvenience,thecharacteristicvalueofseismiccoefficientforverificationofquaywallswithrelievingplatformsmaybecalculatedbyreferencetothe2.2.2(1) Seismic Coefficient for Verification used in Verification of Damage due to Sliding and Overturning of Wall Body and Insufficient Bearing Capacity of Foundations Ground in Variable Situations in Respect of Level 1 Earthquake Ground Motion,complyingwithgravity-typequaywalls.

(6)Itisnotdesirablethatthewidthoftherelievingplatformbeshortenedtotherangewhereitdoesnotintersectwiththeactivefailuresurfaceextendingfromtheseabedsurface.However,iftheuseofashortrelievingplatformisunavoidable,thefollowingmethodcanbeusedasthemethodofcalculatingtheactiveearthpressureactingonthesheetpile. AsshowninFig. 2.8.5, theearthpressureactingonthesheetpilewalliscalculatedastheearthpressureactinginthecasethatthereisnorelievingplatformbelowtheintersectionpointoftheactivefailuresurfacedrawnfromtherearendoftherelievingplatformandthesheetpile,andastheearthpressureactingin(2)above,abovethepointofintersectionofthenaturalfailuresurfaceduringLevel1earthquakegroundmotiondrawnfromtherearendoftherelievingplatformandthesheetpile.Betweenthesetwo,itmaybeassumedthattheearthpressurevarieslinearly. Thedesignvalueof the angleα formedbetween thenatural failure surface and thehorizontalduring anearthquakecangenerallybeobtainedfromequation(2.8.1).Inthefollowingequation,thesubscriptdindicatesthedesignvalue.

(2.8.1)

where, φ :angleofshearingresistanceofthesoil(°) kh' :apparentseismiccoefficient

Thedesignvaluesintheequationmaybecalculatedfromthefollowingequation.Intheequation,thesymbolγisthepartialfactorcorrespondingtoitssubscript,andthesubscriptskanddindicatethecharacteristicvalueand

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thedesignvalue,respectively.Also,thepartialfactorsmayallbeassumedtobe1.0.

(2.8.2)

Active failure surface

Design tide level(L.W.L.)

α= -tan-1k'φα= -tan-1k'φ

Fig. 2.8.5 Earth Pressure Acting on Sheet Pile with Narrow Relieving Platform

(7)Thehorizontalforcetransmittedfromthesheetpilewallmaybecalculatedwiththesamemethodasthatforthereaction forceat the tie rodsettingpointobtained inaccordancewith2.3.4 Performance Verificationof2.3 Sheet Pile Quaywalls byregardingthebottomelevationofrelievingplatformasatierodsettingpoint.

(8) Thetractiveforceofshipsandfenderreactionforcealsoactontherelievingplatform. Theseexternalforcesshouldbeconsideredasnecessary.

(9) Theexternalforcestransmittedfromthesheetpilewalltotherelievingplatformincludethehorizontalforceandflexuralmoment.However,thetransmissionoftheflexuralmomentisignoredforthesakeofsafety,becausethefixingofthesheetpilestotherelievingplatformmaynotberigidenough.

(10)TheearthpressureandresidualwaterpressureactingonthebackoftherelievingplatformcanbecalculatedinaccordancewithPart II, Chapter 5, 1 Earth Pressure andPart II, Chapter 5, 2.1 Residual Water Pressure.Inthecalculationofearthpressure,surchargeshouldbetakenintoconsideration.Inthepartbelowthebottomofrelievingplatform,thedifferencebetweenactionearthpressureactingontherearandthepassiveearthpressureactingonthefrontactsastheactiveearthpressuredowntothedepthwherethetwopressuresarebalanced.ThisshouldbeaddedasshowninFig. 2.8.6.Thefrictionangleofthewallmaybetakentobe15°foractiveearthpressure,and–15°forpassiveearthpressure.

pp pa

pa

pa- pp

Force transmittedfrom sheet piling Residual water level

Residual water pressureDesign tide level(L.W.L)

Fig. 2.8.6 External Forces to be Considered for Performance Verification of Relieving Platform


(1)PerformanceVerificationofSheetPileWall

① Theembeddedlengthofsheetpilescanbeexaminedbyassumingthatthejointbetweenthesheetpilewallandrelievingplatformisahingesupport,replacingthebottomoftherelievingplatformwithatierodsettingpointandapplying2.3 Sheet Pile Quaywalls.

② Verificationofstressesinthesheetpilewallmaybecarriedoutinaccordancewith2.3 Sheet Piled Quaywalls,replacingtherelievingplatformbottomsurfacewiththetieinstallationpoint.

③ Inadditiontotheflexuralmomentduetoearthpressure, theflexuralmomentandverticalforcetransmittedfromtherelievingplatformactonthesheetpilesofasheetpilewall.Normallytheflexuralmomenttransmittedfromtherelievingplatformisnottakenintoconsideration,becauseitusuallyactsinadirectionoppositetothat


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ofthemaximumflexuralmomentthatactsonthesheetpilesandthusreducesthemaximumflexuralmoment.Furthermore,theverticalforcetransmittedfromtherelievingplatformtothesheetpilewallisnormallynottakenintoconsiderationwhenthefrontrowofrelievingplatformpilesisdriveninasclosetothesheetpilewallaspossibleandthissignificantlyreducestheverticalforceactingonthesheetpiles.

(2)PerformanceVerificationoftheRelievingPlatform

Arelievingplatformshouldbeverifiedforperformanceasacontinuousbeamforboththedirectionofquaywallalignmentandthedirectionperpendiculartothealignment(seeFig. 2.8.7).Loadsshouldnotbedistributedinthetwodirections.WhentherelievingplatformisanL–shapedstructure,theuprightsectionshouldbeverifiedforperformanceasacantileverbeamsupportedattheslabsection.

Coupled piles +

+M0Ap

M0

Ap

w wd

w wd

Vertical pile

Bending moment

Bending moment due to surcharge

Bending moment transmitted from upright part

Tensile force

M0 : Maximum bending moment of upright partAp : Force transmitted from sheet pileW : Surchargewd : Load due to deadweight and soil

Fig. 2.8.7 Continuous Beam Assumed in Performance Verification of Relieving Platform

(3)PerformanceVerificationoftheRelievingPlatformPiles

① Performance of relieving platform piles can be verified in accordance with Part II, Chapter 2, 2.4 Pile Foundations.

② Inprinciple,relievingplatformpilesshouldconsistofacombinationofcoupledpilesandverticalpiles.Thehorizontalexternalforcemaybebornebythecoupledpilesonly,andtheverticalexternalforcemaybebornebytheverticalpilesonly.Itmaybeassumedthateachofthecoupledpilesburdensthehorizontalforceequally.

③ Inthedesignofrelievingplatformpiles,assessmentshouldbemadeforthemostdangerousstateofeachpilebyvaryingthesurcharge,directionofseismicforces,andsealevelwithinthedesignconditionranges.

④ Incalculatingtheaxialloadresistanceofeachoftherelievingplatformpiles,itisdesirabletoassumethatinthegroundabovethesheetpileactivefailuresurfacedrawnfromtheseabedsurface,theskinfrictiondoesnotcontributeastheresistanceforceoftherelievingplatformpiles.

⑤ Ifitisunavoidablethattherelievingplatformpilesareallcomposedbyverticalpiles,whendistributingthehorizontalforcetotheverticalpiles,normallyitisassumedincalculatingtheresistanceforcenormaltotheiraxesthatthereisnosoilabovethesheetpileactivefailuresurfacedrawnfromtheseabedsurface.

(4)AnalysisoftheStabilityasGravity-typeWallStructures

① Theexaminationofthestabilityofaquaywallwithrelievingplatformasawholecanbemadebyassumingthatthequaywallwithrelievingplatformisakindofgravity-typewall.

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② Foranalyzingthestabilityoftheassumedgravity-typewallstructure,referto2.2 Gravity-type Quaywalls.Inthiscase,thepassiveearthpressuretothefrontofthesheetpileisconsidered.

③ Aquaywallwithrelievingplatformmaybeconsideredasarectangularshapegravity-typewalldefinedbyaverticalplanecontainingtherearfaceoftherelievingplatformandahorizontalplanecontainingthebottomendsofthefrontsidebatterpilesofthecoupledpiles,asshowninFig. 2.8.8.

W.L.

Fig. 2.8.8 Virtual Wall as Gravity-type Wall

(5)VerificationofCircularSlipFailureForanalysisofcircularslipfailure,refertoChapter 2, 3 Stability of Slopes.Inthiscaseanalysisiscarriedoutforcircularslipfailurepassingunderthebottomendofthesheetpile.Also,forsettingthetidelevel,refertoPart II, Chapter 2, 3 Tide Levels.

part iii facilities, chapter 5 mooring facilities · 2017-08-15 · part iii facilities, chapter 5...

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