chapter 5 earth pressure and water pressurepart ii actions and material strength requirements,...

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 5 EARTH PRESSURE AND WATER PRESSURE

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Chapter 5 Earth Pressure and Water Pressure

Public NoticeEarth Pressure and Water Pressure

Article 14 1Earthpressureshallbesetappropriatelybasedonthegroundconditionsinconsiderationofthestructureofthefacilitiesconcerned,imposedloads,theactionofearthquakegroundmotions,andothers.

2Residual water pressure shall be set appropriately in consideration of the structure of the facilitiesconcerned,thesurroundinggroundconditions,tidelevels,andothers.

3Dynamic water pressure shall be set appropriately in consideration of the structure of the facilitiesconcerned,theactionofearthquakegroundmotions,andothers.

[Technical Note]

1 Earth Pressure1.1 GeneralThebehaviorofsoilvarieswithphysicalconditionssuchasgrainsize,voidratioandwatercontent,andwithstresshistoryandboundaryconditions,whichalsoaffectearthpressure.Theearthpressurediscussedinthischapteristhepressurebyordinarysoil.Theearthpressuregeneratedbyimprovedsoilandreinforcedsoilwillrequireseparateconsideration.Theearthpressureduringanearthquakefordesignmentionedherein,isbasedontheconceptoftheseismiccoefficientmethodand isdifferent from theactualearthpressuregeneratedduringanearthquakecausedbydynamicinteractionbetweenstructures,soilandwater. However, thisearthpressurecangenerallybeusedinperformanceverificationsasrevealedbyanalysesofpastdamageduetoearthpressuresduringearthquakes. Thehydrostaticpressureanddynamicwaterpressureactingonastructureshouldbecalculatedseparately.

(1)EarthPressure(RelatingtoItem1ofthePublicNoticeAbove)Insettingearthpressure,appropriateconsiderationshouldbegiventotheearthpressurestate,namelywhetheritisanactiveorapassiveearthasaresultofstructurebehavioretc.,andthedesignsituation,inaccordancewiththetypeofsoilqualitysuchassandyorcohesivesoilandthestructuralcharacteristicsofthesubjectfacility.

(2)ResidualWaterPressure(RelatingtoItem2ofthePublicNoticeAbove)Residualwaterpressurementionedhereinreferstothewaterpressurearisingfromthedifferenceinwaterlevelsonthefrontsideandrearsideofthefacility.Thisdifferencemustbegivendueconsiderationinsettingresidualwaterpressure.

(3)DynamicWaterPressure(RelatingtoItem3ofthePublicNoticeAbove)Inverifyingtheperformanceoffacilitiessubjecttothetechnicalstandard,properconsiderationshouldbegiven,asrequired,totheeffectofdynamicwaterpressure.

(4)OtherInverifyingtheperformanceoffacilitiessubjecttothetechnicalstandard,buoyancyshouldbeconsidered,asrequired,inadditiontothesesettings.

1.2 Earth Pressure at Permanent Situation1.2.1 Earth Pressure of Sandy Soil

(1)Theearthpressureofsandysoilactingonthebackfacewallofstructureandtheangleofslidingsurfaceshallbecalculatedbythefollowingequations:

① Activeearthpressureandtheangleoffailuresurface

(1.2.1)

(1.2.2)

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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN

where

② Passiveearthpressureandtheangleoffailuresurface.

(1.2.3)

(1.2.4)

where

with pai,ppi :active andpassive earth pressures, respectively, acting on the backface of thewall at the bottomlevelofthei-thsoillayer(kN/m2) φi :angleofinternalfrictionofthei-thsoillayer(°) γ i :unitweightofthei-thsoillayer(kN/m3) hi : thicknessofthei-thsoillayer(m) Kai,Kpi :coefficientsofactiveandpassiveearthpressures,respectively,inthei-thsoillayer ψ :angleofbatterofbackfacewallfromverticalline(°) β :angleofbackfillgroundsurfacefromhorizontalline(°) δ :angleoffrictionbetweenbackfillingmaterialandbackfacewall(°) ζ i :angleoffailuresurfaceofthei-thsoillayer(°) ω :uniformlydistributedsurchargeonthegroundsurface(kN/m2)

(2)TheearthpressureatpermanentsituationisbasedonCoulomb'searthpressuretheory.

(3)Earthpressureatrestasexpressedbyequation (1.2.5)maybeusedwhenthereislittledisplacementbecauseofthewallbeingconfined.

(1.2.5)

where K0 :coefficientofearthpressureatrest

(4)AngleofInternalFrictionofSoilTheangleofinternalfrictionofbackfillsoilnormallyhasavalueof30°.Incaseofespeciallygoodbackfillingmaterial,itcanbesetaslargeas40°.Itispossibletousetheresultsofsoiltestsand/ortoestimatetheangleofinternalfrictionofsoilbyreliableestimationformulas.

(5)AngleofFrictionbetweenBackfillingMaterialandBackfaceWallTheangleoffrictionbetweenbackfillingmaterialandbackfacewallnormallyhasavalueof±15–20°.Itmaybeestimatedasone-halfoftheangleofinternalfrictionofbackfillingmaterial.

(6)UnitWeightofSoil.Theunitweightofsoilnormallyhasavalueof18kN/m3asunsaturatedsoilsuchasasoilabovetheresidualwaterlevel,and10kN/m3assaturatedsoilbelowit.

(7)CalculationFormulaforResultantForceofEarthPressureThe resultant forceofearthpressure iscalculatedat each layer. Theobjective force for the i-th layercanbecalculatedusingequation(1.2.6).

(1.2.6)

Moreover,thehorizontalandverticalcomponentsoftheresultantforceofearthpressurecanbecalculatedusingequations(1.2.7)and(1.2.8).

(1.2.7)


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(1.2.8)where

Pih:horizontalcomponentoftheresultantforceofearthpressurePiv:verticalcomponentoftheresultantforceofearthpressure

Fig. 1.2.1 Schematic Diagram of Earth Pressure Acting on Retaining Wall

1.2.2 Earth Pressure of Cohesive Soil

(1)The earth pressure of cohesive soil acting on the backfacewall of structure shall generally be calculated byfollowingequations:

① ActiveEarthPressure

(1.2.9)

② PassiveEarthPressure

(1.2.10)

where pa :activeearthpressureactingonthebottomlevelofthei-thsoillayer(kN/m2) pp :passiveearthpressureactsonthebottomlevelofthei-thsoillayer(kN/m2) γ i :unitweightofthei-thsoillayer(kN/m3) hi :thicknessofthei-thsoillayer(m) ω :uniformlydistributedsurchargeonthegroundsurface(kN/m2) c :cohesionofsoil(kN/m2)

(2)Theearthpressureofcohesivesoil isverycomplex. Theequationsabovearebasedonexpedientcalculationmethodsandmustbeappliedwithcare.

(3)Active earth pressure can be calculated using equation (1.2.9). If a negative earth pressure is obtained bycalculation,thepressureshouldbeassumedtobezerodowntothedepthwherepositiveearthpressureexerts.

(4)Equation (1.2.11)maybeusedforearthpressureatrest.

(1.2.11)

where K0 :coefficientofearthpressureatrest

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(5)CohesionofSoilCohesionofsoilshouldbedeterminedusinganappropriatemethod,refertoChapter 3,2.3.3 Shear Characteristics.Forexample,equation (1.2.12)shouldbeusedwhenusingresultsofunconfinedcompressiontests.

(1.2.12)

where qu :unconfinedcompressivestrength(kN/m2)

(6)AngleofFrictionbetweenBackfillingMaterialandBackfaceWallIncaseofcohesivesoil,thecohesionbetweenbackfillandbackfacewallshouldbeignored.

(7)UnitWeightofCohesiveSoilTheunitweightofcohesivesoilshouldbeestimatedbysoiltest.Thewetunitweightγ tshouldbeusedforsoilsabovetheresidualwaterlevel,andthesubmergedunitweightγ ' beusedforsoilsbelowtheresidualwaterlevel.

1.3 Earth Pressure during Earthquake1.3.1 Earth Pressure of Sandy Soil

Theearthpressureofsandysoilactingonabackfacewallofstructureduringanearthquakeandtheangleoffailuresurfaceshallbecalculatedbyfollowingequations:

(1)ActiveEarthPressureandtheAngleofFailureSurfacefromtheHorizontalSurface

(1.3.1)

(1.3.2)

where

(2)PassiveEarthPressureandtheAngleofFailureSurfacefromtheHorizontalSurface

(1.3.3)

(1.3.4)

where

The notations pai，ppi，Kai，Kpi，ζ i，ω，γi，hi，ψ，β，δ and φi, are the same as those defined in 1.2 Earth Pressure at Permanent Situation, equation (1.2.1) to(1.2.4).Also,θisdefinedasfollows.

θ :compositeseismicangle(º)shownasfollowing(a)or(b):(a) θ =tan–1k(b)θ =tan–1k'

wherekandk'areasshownbelow; k :seismiccoefficient k' :apparentseismiccoefficient


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(3)Apparentseismiccoefficientshallbeinaccordancewith1.3.3 Apparent Seismic Coefficient.

(4)EarthpressureduringanearthquakeisbasedonthetheoriesproposedbyMononobe1)andOkabe.2)

(5)AngleofFrictionBetweenBackfillingMaterialandBackfaceWallAngleoffrictionbetweenbackfillingmaterialandbackfacewallnormallyhasavalueof±15andbelow.Itmaybeestimatedasone-halfoftheangleofinternalfrictionofbackfillingmaterial.

(6)EarthPressurebelowResidualWaterLevelGenerally,theearthpressuredistributionabovetheresidualwaterlevelandbelowtheresidualwaterlevelshouldbedeterminedbyusingtheseismiccoefficientinairandtheapparentseismiccoefficientshownin1.3.3 Apparent Seismic Coefficientrespectively.Thecompositeseismicanglek isusedforsoilsabovetheresidualwaterlevel,andk’isusedbelowit.

(7)CoefficientofEarthPressureThecoefficientofearthpressureandangleoffailuresurfacecanbeobtainedfromthediagramsinFig. 1.3.1.

(8)Theearthpressuretheoryassumesthatthesoilandtheporewaterbehaveintegrally.Thustheequationsmentionedabovecannotbeappliedtoliquefiedsoil.Itisnecessaryforliquefiedsoiltoevaluatetheseismicstabilityofthegroundandstructureswithdynamiceffectivestressanalysisormodeltests.

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Fig. 1.3.1 Coefficient of Earth Pressure and Failure Angle


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1.3.2 Earth Pressure of Cohesive Soil

Theearthpressureofcohesivesoilactingonawallofthestructureduringanearthquakeandtheangleofthefailuresurfaceagainstthehorizontalsurfaceshallgenerallybecalculatedasfollows:

(1)ActiveEarthPressureActiveearthpressureshallbecalculatedusinganappropriateearthpressure formulawhich takes theseismiccoefficientintoaccountsothatthestructuralstabilitywillbesecuredduringanearthquake.Generally,theactiveearthpressurecanbecalculatedusingequation (1.3.5)andtheangleoffailuresurfaceusingequation (1.3.6).

(1.3.5)

(1.3.6)

where pa :characteristicvalueoftheactiveearthpressure(kN/m2) γ i :unitweightofthesoil(kN/m3) hi :thicknessofthesoillayer(m) ω :surchargeloadperhorizontalsurfacearea(kN/m2) c :cohesionofthesoil(kN/m2) θ :expressedascompositeseismicangle 1tan kθ −= (°)or 1tan kθ − ′= (°). k :seismiccoefficient k' :apparentseismiccoefficient ζ a :angleofthefailuresurface(°)

(2)PassiveEarthPressurePassive earth pressure shall be calculated using an appropriate earth pressure formula so that the structuralstabilitywillbesecuredduringanearthquake. Therearemanyunknownfactorsconcerningthemethodfordeterminingthepassiveearthpressureofcohesivesoilduringanearthquake.Conventionally,however,equation (1.2.10)in1.2.2 Earth Pressure of Cohesive Soilforobtaining theearthpressureofcohesivesoil isused in linewithmethodsforearthpressurecalculationatPermanentsituation.Atpresent,equation (1.2.10)canbeusedasanexpedientmethod.

(3)Theapparentseismiccoefficientshouldbeusedtocalculatetheearthpressureofcohesivesoildowntotheseabottomduringanearthquake. Theapparentseismiccoefficientmaybesetaszerowhencalculatingtheearthpressureatthedepthof10mfromtheseabottomordeeper.However,iftheearthpressureatthedepthof10mbelowtheseabottombecomeslessthantheearthpressureattheseabottom,thelattershouldbeapplied.

1.3.3 Apparent Seismic Coefficient

(1)Theearthpressureactingonthesoilbelowthewaterlevelduringanearthquakecanbecalculatedaccordingtotheproceduresoutlinedin1.3.1 Earth Pressure of Sandy Soil and1.3.2 Earth Pressure of Cohesive Soil, byusingtheapparentseismiccoefficientwhichisgenerallydeterminedbythefollowingequation:

(1.3.7)

where k' :apparentseismiccoefficient γ t :unitweightofsoillayerabovetheresidualwaterlevel(kN/m3) hi :thicknessofthei-thsoillayerabovetheresidualwaterlevel(m) γ :unitweightintheairofsaturatedsoillayer(kN/m3) hj :thicknessofthej-thsoillayerabovethelayerforwhichearthpressureisbeingcalculatedbelow

theresidualwaterlevel(m) ω :surchargeloadperunitareaofthegroundsurface(kN/m2) h :thicknessofsoillayerforwhichearthpressureisbeingcalculatedbelowtheresidualwaterlevel(m) k :seismiccoefficient

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(2)Presently,equation (1.3.7) 3)isgenerallyusedforcalculatingearthpressureduringanearthquake,asitcanbeappliedtolight-weightfillingmaterialandothernewmaterials,andisbelievedtobethemostrationalmethod.

(3)Ontheassumptionthatsoilgrainandwatermoveinanintegratedmannerwithrespecttosoilunderthewaterlevelduringanearthquake,theforceofthegroundmotionactingonthesoilwouldbetheproductofthesoil'ssaturatedweightmultipliedbytheseismiccoefficient.Moreover,sincethesoilunderthewaterlevelisendowedwithbuoyancy,theverticalforceactingonthesoilisthesoil'sunder-waterweight.Therefore,theresultantforceonthesoilunderthewaterlevelduringanearthquakewouldbedifferentfromthatintheair.Whencalculatingearthpressureduringanearthquake,theequationfordeterminingearthpressureduringanearthquakeforsoilintheaircanalsobeusedwithsoilunderwaterbyapplyingapparentseismiccoefficientdeducedfromthecompositeseismicangle. Theverticalforceactingonsoilunderwaterincludestheweightofthesoillayersabovethelayerforwhichearthpressureisbeingcalculatedaswellasthesurchargeload.Henceapparentseismiccoefficientisaffectedbythesefactors.

First stratum

First stratum

First j stratum

First i stratum

Second stratum

Residual water level R.W.L.

Stratum for which earthpressure will be calculated

hj

ih

h

Fig. 1.3.2 Symbols for Apparent Seismic Coefficients

References

1) Mononobe,N.:SeismicCivilEngineering,Riko-ToshoPublishing,19522) Okabe,S.:GeneralTheoryonEarthPressureandSeismicStabilityofRetainingWallandDam,JournalofJSCEVol.10,No.

6,p.1277,19243) Arai,H.andT.Yokoi:Studyonthecharacteristicsofearthquake-resistanceofsheetpilewall(ThirdReport)Proceedingsof

3rdconferenceofPHRI,Vol.1l4No4,1975


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2 Water Pressure2.1 Residual Water Pressure

(1)When mooring facilities etc. have watertight structures or when backfilling material and backfilling soil(hereinafterreferredtointhisparagraphas"backfilling")havelowpermeability,thereisatimedelayinthewaterlevelchangesinthebackfillingasopposedtothewaterlevelatthefrontandthedifferenceofwaterlevelappears.Whencarryingoutperformanceverificationsonmooringfacilitiesetc.,whatneedstobecheckedistheconditionsthatdevelopwhenthewaterlevelinthebackfillingishigherthanthatatthefrontandwhenthatdifferenceisatitsgreatest.Residualwaterpressurereferstothewaterpressureactingonthemooringfacilitiesetc.underthiscondition. Themagnitudeoftheresidualwater-leveldifferencevariesdependingonthepermeabilityofthewallsandsurroundingmaterialsmakingup themooring facility etc. aswell as the tidal range. Thegeneralvalues forresidualwater-leveldifferencebystructuraltypeareshowninsectionsrelatingtoperformanceverificationoftherespectivefacilities.Valuesotherthanthesegeneralvaluesmaybeusedwhendeterminingresidualwater-leveldifferencefromsurveysconductedonsimilarstructuresnearbyorfrompermeabilitycheckscarriedoutonthewallsandsurroundingground.

(2)Theresidualwaterpressurecausedbythetimedelayofwaterlevelchangesbetweenthesealevelandtheresidualwaterlevelcanbecalculatedusingthefollowingequation:

①Wheny islessthanhw

(2.1.1)

②Wheny isequaltoorgreaterthanhw

(2.1.2)

where pw :residualwaterpressure(kN/m2) ρwg :unitweightofseawater(kN/m3) y :depthofsoillayerfromtheresidualwaterlevel(m) hw :waterleveldifferencebetweenthewaterlevelinfrontandbehindthefacility(m)

Residual Water Level R.W.L

Resid

ual W

ater

Pre

ss

y

ghw wρ

wh

Fig. 2.1.1 Schematic Diagram of the Residual Water Pressure

(3)Theresidualwaterlevelisdeterminedinconsiderationoffactorssuchaspermeabilityofbackfillsoil,andtidalrange.Normallytheheighthw willbe1/3-2/3ofthetidalrange.

(4)Afterafacilityiscompleted,thepermeabilityofitswallsandsurroundingmaterialsmaydiminishwithtime.Therefore,when the anterior tidal range is sizeable, itwould be preferable to take that into consideration indeterminingresidualwater-leveldifference.

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2.2 Dynamic Water Pressure

(1) Items(2)through(8)belowshouldbefollowedwhenusingperformanceverificationequationsthatmakeuseofcharacteristicvaluesofdynamicwaterpressurewhereasitem(9)shouldbefollowedinperformingverificationsthat use techniques such as the finite elementmethod for taking the effects of dynamicwater pressure intoconsideration.

(2)Normally,methods based on the dynamicwater pressure on steady oscillation 1) are used for calculating thecharacteristicvaluesofthedynamicwaterpressure.However,inviewofthephaserelationshipofotheractions,whenaparticularneedarises,thedynamicwaterpressureonirregularoscillationshouldbecalculated. Also, ifa liquidoccupiesspaces inside thefacility, thedynamicpressureof the liquidmustbe takenintoconsideration.Ifdynamicwaterpressureisactingonbothsidesofthefacility,thesumoftheresultantforceofthedynamicwaterpressurebecomestwo-fold.Dynamicwaterpressureneedsnotbeconsideredinthefollowingcases:

①When performance verifications can be performed without taking dynamic water pressure directly intoconsiderationduetostructuralcharacteristics;

②Whenusingverificationmethodsthatdonottakedynamicwaterpressuredirectlyintoaccount.Thiswouldrequiresufficientrecordsofresults.

Morespecifically,thiswouldbeinthefollowingcases:

(a) Dynamicwaterpressureofporewaterinthecaissonfilling

(b)Dynamicwaterpressureofporewaterinbackfillingmaterialsandbackfillingsoilofmooringquaywallsetc.

(c) Dynamicwaterpressureforthebottomslabreinforcementdesignofcaisson

(3)Thedynamicwaterpressureduringanearthquakeforstructuresinwaterandfacilitieswithinteriorspacesthatarepartiallyorfullyfilledwithwatercanbecalculatedusingthefollowingequation:

(2.2.1)

where pdw :dynamicwaterpressure(kN/m2) kh :seismiccoefficient γw :unitweightofwater(kN/m3) H :heightofstructurebelowthestillwaterlevel(m) y :depthofthedynamicwaterpressurecalculationlevelfromthestillwaterlevel(m)

The resultant forceofdynamicwaterpressureand itsactingheightcanbecalculatedby the followingequation:

(2.2.2)

Here,Pdwandhdwarethefollowingvaluesandkh,pwandHareequaltothevaluesofkh,pwandHinitem(3)aboverespectively.

:resultantforceofdynamicwaterpressure(kN/m)

hdw :depthoftheactingpointofthedynamicwaterpressureresultantforcefromthestillwaterlevel(m)

(4)Theactionofthedynamicwaterpressurebothinthefrontandthebackofthewallisdirectedtowardsthesea.

(5)Inthecaseofstructuresusing1.3.3 Apparent Seismic Coefficient(equation (1.3.7)),thedynamicwaterpressureactingonthefrontsideofthewallshouldbedirectedseawards,anddynamicwaterpressureontherearsideofthewallneedsnotbeconsidered.

(6)Wherethewallisinclined,thedynamicwaterpressureactingonthatsurfaceissmallerthanthatactingonaverticalwall.Thisisbecause,thedirectionofmotionofthewaterparticlesarediverteddiagonallyupwardsalongtheinclinedsurface.DynamicwaterpressureinthiscasecanbecalculatedusingthemethodproposedbyZanger2)etal.


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References

1) Westergaaard, H.M.: Water Pressures on Dams during Earthquakes, Journal of ASCE. Transactions, No,1835, pp.418-472,1933

2) Zanger, C.N.: Hydrodynamic Pressure on Dams due to Horizontal Earthquake, Proc. Exper. Stress Analysis, Vol.lO,No.2,1953

3) Iai,S.,Matsunaga,Y.andKameoka,T.:Strainspaceplasticitymodel forcyclicmobility,SoilsandFoundation,JapaneseSocietyofSoilMechanicsandFoundationEngineering,Vol.32,No.2,PP.1-15,1992

4) Zienkiewicz,O.C.:MatrixFiniteElementMethod,ThirdEdition,Bai-fuKanPublishing,1984

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Chapter 6 Ground Liquefaction

Public Notice Ground Liquefaction

Article 17Thepossibilityandextentofgroundliquefactionshallbeassessedwithappropriatemethodsbasedonthegroundconditionsandbytakingaccountoftheactionsfromearthquakegroundmotions.

[Commentary]

(1)EffectsofLiquefactionintheCaseofLevel1EarthquakeGroundMotionsAs for theconsiderationof liquefaction in thecaseof level2 earthquakegroundmotions,measuresagainstliquefactionaretakentoprotectthegroundconcernedwhenliquefactionispredictedandjudgedtooccur,takingaccountoftheeffectsofliquefactiononstructuresandthesurroundingsituationsofthefacilitiesconcerned.

(2)EffectsofLiquefactionintheCaseofLevel2EarthquakeGroundMotionsAsfortheconsiderationofliquefactioninthecaseofLevel2earthquakegroundmotions,themethodsoftakingmeasuresagainstliquefactionandthenecessityoftheirimplementationaredeterminedbasedonacomprehensiveevaluationofthesituationsofthefacilitiesconcerned.

[Technical Note]

1 GeneralThe subjects described in thisChaptermay refer toHandbook of Liquefaction Measures for Reclaimed Land (Revised Edition).1)

ThefollowingmethodsareforthestudyofgroundliquefactioninthecaseofLevel1earthquakegroundmotions.

As for theconsiderationof liquefaction in thecaseofLevel2earthquakegroundmotions, themethodsof takingmeasures against ground liquefaction and the necessity of their implementation shall be determined based on acomprehensiveevaluationofthesituationsofthefacilitiesconcerned.RefertoChapter 4 EarthquakesofthisPartIIandthedescriptionontheperformanceverificationoffacilitiesinPart3fortheevaluation.

2 Prediction and Judgment of Liquefaction

(1)Thepredictionandjudgmentofwhetherornotthegroundisliquefiedaregenerallyperformedbypropermethodsusinggrainsizesandstandardpenetrationtestvaluesortheresultsofcyclictriaxialtests.

(2)MethodsofPredictionandJudgmentofLiquefactionLiquefactionpredictionandjudgmentmethodsincludethemethodusinggrainsizesandNvaluesorthatusingtheresultsofcyclictriaxialtests.ThemethodusinggrainsizesandNvaluesissimpleandeasyandcanbegenerallyusedforpredictingandjudgingliquefaction.ThemethodusingtheresultsofcyclictriaxialtestsismoredetailedandcanbeusedwhenthepredictionandjudgmentusinggrainsizesandNvalueshavebeenfounddifficultandmoredetailedapproachesareneeded.

(3)PredictionandJudgmentofLiquefactionUsingGrainsizeandN-values.2)

① JudgmentbasedongrainsizeThesubsoilsshouldbeclassifiedaccordingtograinsize,byreferringtoFig.2.1,towhichapplicationdependsonthevalueoftheuniformitycoefficient.Thethresholdvalueoftheuniformitycoefficient(Uc=D60/D10)is3.5,whereUc istheuniformitycoefficient,andD60andD10denotethegrainsizescorrespondingto60%and10%passing,respectively.Soilisjudgednottoliquefywhenthegrainsizedistributioncurveisnotincludedintherange“possibilityofliquefaction”inFig. 2.1.

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 6 GROUND LIQUEFACTION

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Clay Silt Sand GravelGrain size (mm)

For soil with large uniformity coefficient (Uc　 3.5)

Perc

enta

ge p

assi

ng b

y m

ass (

%)

00.01 0.1 1.0 10

25

50

75

100

0.005 0.075 2.0

Very large possibilityof liquefaction

Possibility of liquefaction

Fig. 2.1(a) Range of Possible Liquefaction (Uc ≧ 3.5)

Perc

enta

ge p

assi

ng b

y m

ass (

%)

Clay Silt

Grain size (mm)

Sand Gravel

Very large possibilityof liquefaction

Possibility of liquefaction

For soil with small uniformity coefficient (Uc 3.5)

00.01 0.1 1.0 10

25

50

75

100

0.005 0.075 2.0

Fig. 2.1(b) Range of Possible Liquefaction (Uc < 3.5)

Whenthegrainsizedistributioncurvespansthe“possibilityofliquefaction”range,asuitableapproachisrequiredtoexaminethepossibilityofliquefaction.Forsoilwithalargeportionoffinegrainsizedistribution,acyclictriaxialtestshouldbecarriedout.Forsoilwithalargegravelportion,thesoilisdeterminednottoliquefywhenthecoefficientofpermeabilityis3cm/sorgreater.Whentherearesubsoilswithpoorpermeabilitysuchasclayorsiltontopofthetargetsubsoilinthiscase,however,itshouldbetreatedassoilthatfallswithintherangeof“possibilityofliquefaction”. Apermeabilitytestforthesoilwiththepermeabilityoflargerthan3cm/sshallbeaspecialmethod.3) Amethod of indirect estimation of permeability is availablewhen the permeabilitymeasurement is difficult.However,careaboutthesoilcharacteristics,suchascontentoffineparticlesshallbepaidtoapplytheindirectestimationmethod.

② PredictionandjudgmentofliquefactionusingequivalentN-valuesandequivalentaccelerationForthesubsoilwithagrainsizethatfallswithintherange“possibilityofliquefaction”showninFig. 2.1,furtherinvestigationsshouldbecarriedbythedescriptionsbelow.

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(a) EquivalentN-valueTheequivalentN-valueshouldbecalculatedfromequation (2.1).

(2.1)

where(N)65 :equivalentN-value N :N-valueofthesubsoil σv' :effectiveoverburdenpressureofthesubsoil(kN/m2) (Theeffectiveoverburdenpressureusedhereshouldbecalculatedwithrespecttotheground

elevationatthetimeofthestandardpenetrationtest.)

Fig. 2.2showstherelationshipgivenbyequation (2.1).Whenusingequation(2.3)describedbelow,theNvaluesthemselvesofthesoillayerareassumedtobeequivalentNvalues.

0

50

100

150

200

250

3000 10 20 30 40 50 60 70

(N )65 = 2(N

)65 = 5

(N )65 = 7(N )65 = 10

(N )65 = 15(N )65 = 20

(N )65 = 25(N )65 = 30

N-value

effe

ctiv

e ov

erbu

rden

pre

ssur

e 　(kN

/m2)

Fig. 2.2 Calculation Chart for Equivalent N-value, the Straight Lines show the Relationship between N-values and Effective Overburden Pressures when Relative Densities are Constant

(b)EquivalentaccelerationsEquivalentaccelerationsarecalculatedfromequation (2.2).Theyarecalculatedforeachsoillayerusingthemaximumshearstressesobtainedfromtheresultsoftheseismicresponseanalysesoftheground.

(2.2)where αeq :equivalentacceleration(Gal) τmax :maximumshearstress(kN/m2) σV’ :effectiveoverburdenpressure(kN/m2)(Notethattheeffectiveoverburdenpressuresusedfor

calculatingequivalentaccelerationsareobtainedbasedon thegroundheightsat the timeofearthquakes.)

g :gravitationalacceleration(980Gal)

(c) PredictionsandjudgmentusingtheequivalentN-valueandequivalentaccelerationThesubjectsoillayershouldbeclassifiedaccordingtotherangeslabeledI–IVinFig. 2.3,usingtheequivalentN-valueandtheequivalentaccelerationofthesoillayer.


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Equivalent acceleration (Gal)

Equi

vale

nt N

-val

ue

ⅠⅡ

Ⅲ

Ⅳ

0 100 200 300 400 500 6000

5

10

20

25

30

15

(333,25)

(300,16)(300,16)(450,16)(450,16)

(150,7)(150,7)

(100,7)(100,7)(66,7)

Fig. 2.3 Classification of Soil Layer with Equivalent N-Value and Equivalent Acceleration

③ Prediction,judgmentandcorrectionofN-valueswhenthefractionoffinescontentisrelativelylarge.

(a)When the fines content, grain size of 75 μm or less, is 5% or greater, the equivalentN-value should becorrectedbeforeapplyingFig. 2.3,thenthesubjectsoilshouldbeevaluatedtowhichrangeofItoIVinFig. 2.3itfalls.CorrectionsoftheequivalentN-valuearedividedintothefollowingthreecases.

(b)Case1:whentheplasticityindexislessthan10orcannotbedetermined,orwhenthefinescontentislessthan15%; TheequivalentN-value,aftercorrection,shouldbesetas(N)65/cN.ThecorrectionfactorcNisgiveninFig. 2.4.TheequivalentN-value,aftercorrection,andtheequivalentaccelerationareusedtodeterminetherangeinFig. 2.4.

0 5 10 15 200

0.5

1.0

Com

pens

atio

n fa

ctor

fo

r equ

ival

ent N

-val

ue C

N

Fines content FC (%)

Fig. 2.4 Correction Factor of Equivalent N-Value Corresponding to Fine Contents

(c) Case2:whentheplasticityindexisgreaterthan10butlessthan20,andthefinescontentis15%orhigher;TheequivalentN-value,aftercorrection,shouldbesetasboth(N)65/0.5andN+ΔN,andtherangeshouldbedeterminedaccordingtothefollowingsituations,wherethevalueforΔNisgivenbythefollowingequation:

(2.3)

1) whenN +∆N fallswithintherangeI,userangeI.2)whenN +∆N fallswithintherangeII,userangeII.3) whenN +∆N fallswithintherangeIIIorIVand(N)65/0.5iswithinrangeI,IIorIII,userangeIII.4)whenN +∆N fallswithinrangeIIIorIVand(N)65/0.5iswithinrangeIV,userangeIV.

(d)Case3:whentheplasticityindexis20orgreater,andthefinescontentis15%orhigher;TheequivalentN-value,aftercorrection,shouldbesetasN +∆N.TherangeshouldbedeterminedaccordingtotheequivalentN-value,aftercorrection,andtheequivalentacceleration.

(e) Fig. 2.5showstherelationshipbetweenfinescontentandplasticityindexwhichisdescribedabove(b),(c)and(d).

– 286–


No corrections

Correction with CN in Fig. 2.4

Correction with ΔN in Equation (2.3)

0 5 15

10

20

Plas

ticity

inde

x Ip

Fine contents FC (%)

Correction with CN in Fig. 2.4 and ∆N by equation (2.3)

Fig. 2.5 N-Value Correction Methods by Fine Contents and Plasticity Index

④ PredictionandjudgmentofliquefactionSinceliquefactionpredictionsmustalsoconsiderthefactorsotherthanphysicalphenomenasuchaswhatdegreeofsafetyshouldbemaintainedinthestructures,itisnotpossibletounconditionallyestablishanycriterionforjudgmentsregardingvariouspredictionresults.Table 2.1showsthejudgmentthatisconsideredasstandard. Inthistabletheterm“predictionofliquefaction”referstothehighorlowpossibilityofliquefactionasaphysicalphenomenon.Incontrast,theterm“judgmentofliquefaction”referstotheconsiderationofthehighorlowpossibilityofliquefactionanddeterminationofwhetherornotthegroundwillliquefy.

Table 2.1 Prediction and Judgment of Liquefaction for Soil Layer According to Ranges I to IV

RangeshowninFig. 2.3 Predictionofliquefaction Judgmentofliquefaction

I Possibilityofliquefactionoccurrenceisveryhigh Liquefactionwilloccur

II Possibilityofliquefactionoccurrenceishigh

Eithertojudgethatliquefactionwilloccurortoconductfurtherevaluationbasedoncyclictriaxialtests.

III Possibilityofliquefactionislow

Eithertojudgethatliquefactionwillnotoccurortoconductfurtherevaluationbasedoncyclictriaxialtests.Foraveryimportantstructure,eithertojudgethatliquefactionwilloccurortoconductfurtherevaluationbaseduponcyclictriaxialtests.

IV Possibilityofliquefactionisverylow Liquefactionwillnotoccur

(4)PredictionandJudgmentBasedontheResultsofCyclicTriaxialTests

①WhenitmaybedifficulttopredictandjudgethepossibilityofsubsoilliquefactionofthesubjectgroundfromtheresultsofgrainsizeandN-values,thepredictionandthejudgmentforsubsoilliquefactionshouldbemadewiththeresultsofaseismicresponseanalysisandcyclictriaxialtestsconductedonundisturbedsoilsamples.

② Theproperconsiderationofthestressstateinthegroundandtheirregularityoftheactionscausedbygroundmotionsisimportantfortheresultsoftheseismicresponseanalysesofthegroundandthoseofcyclictriaxialteststoshowactualphenomenaintheground.

(5)JudgmentofOverallLiquefactionIn the judgmentofoverall subsoil liquefaction for a siteconsistingof soil layers, thecomprehensivedecisionshouldbemadebasedonajudgmentforeachlayerofsubsoil.

(6)LiquefactionPredictionandJudgmentintheCaseofLong-durationGroundMotionsTheliquefactionpredictionandjudgmentmethodusinggrainsizesandN-valuesisanempiricalapproachforthecasesofgroundmotionswhoseprincipalmotionshavedurationofabout20seconds.Itshouldbenotedthatthis


–287–

methodislikelytogivepredictionandjudgmentresultsonthedangersideinthecaseswherethegroundmotionsconcernedhavelongduration.

(7)LiquefactionPredictionandJudgmentintheCasesofLong-periodGroundMotionsTheliquefactionpredictionandjudgmentmethodusinggrainsizesandN-valuesisanempiricalapproachforthecasesofgroundmotionswhoseprincipalmotionshaveaperiodofaboutonesecond.Itshouldbenotedthatthismethodislikelytogivepredictionandjudgmentresultsonthedangersideforcohesivesoilinthecaseswherethegroundmotionsconcernedhavealongperiod.

References

1) CoastalDevelopmentInstituteofTechnology(CDIT):Handbookofliquefactionofreclaimedland(RevisedEdition),19972) Yamazaki,H.,K.Zen andF.KoikeStudy of theLiquefactionPredictionBased on theGrainDistribution and theSPT

N-value,TechnicalNoteofPHRI,No.914,19983) TheJapanGeotechnicalSociety:SoilTestingMethodsandCommentary,pp.271-288,20004) JapanGeotechnicalSociety:GeotechnicalEngineeringHandbook,pp.16-20,1999

–288–


Chapter 7 Ground Subsidence

Public NoticeGround Subsidence

Article 15Influenceofgroundsubsidenceshallbeassessedwithappropriatedmethodsbasedonthegroundconditionsin consideration of the structures of the facilities, imposed load, and the surrounding situations of thefacilitiesconcerned.

[Technical Note]

1.1.1 Ground Subsidence

Ground subsidence includes immediate settlement, consolidation settlement, uneven settlement, lateraldisplacementetc.Theeffectsofgroundsubsidenceshallbeevaluatedbasedongroundconditionsusingpropermethodsandproperlytakingaccountofthestructuresofthefacilitiesconcerned,surcharges,andthe actions caused by groundmotions. The evaluation of ground subsidence may refer toChapter 3 Geotechnical ConditionsofPart IIand2.5 Settlement of Foundation in Chapter 2 of Part III.

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 8 SHIPS

–289–

Chapter 8 Ships

Public NoticeDimensions of Design Ships and Related Matters

Article 181Thedimensionsofdesignships(hereinafterreferstotheshipsusedastheinputdataintheperformanceverification of the facilities subject to theTechnical Standards) shall be set according to themethodsprovidedinthesubsequentitems:(1)Inthecasewheredesignshipsareidentifiable,theirdimensionsshallbeused.(2)Inthecasewheredesignshipsareunidentifiable, thedimensionsshallbeproperlysetbasedonthe

statisticalanalysesofthedimensionsofshipsinoperation.2Theactionsfromshipberthing,shipmovements,andthetractionbyshipsshallbesetaccordingtothemethodsprovidedinthesubsequentitemscorrespondingtoasingleactionorthecombinationsoftwoormoreactionstobeconsideredintheperformancecriteriaandtheperformanceverificationofthefacilitiesconcerned:(1)Theactionsfromshipberthingshallbesetwithappropriatemethodsbytakingaccountofthedimensions

ofdesignships,thestructuresofthefacilitiesconcerned,berthingmethods,berthingvelocities,and/orothers.

(2)The actions from shipmovements shall be setwith appropriatemethods by taking account of thedimensionsofdesignships,thestructuresofthefacilitiesconcerned,mooringmethods,characteristicsofmooringsystem,andthewinds,waves,watercurrents,and/orothersactingondesignships.

(3)Theactionsfromthetractionbyshipsshallbesetwithappropriatemethodsbytakingaccountofthedimensionsofdesign ships,mooringmethods,and thewinds,waves,watercurrents, and/orothersactingondesignships.

[Commentary]

(1)PrincipalDimensionsofDesignShipsDesignshipsarethose,amongtheshipsusingthefacilitiesconcerned,whichareassumedtohavethemostsignificanteffectsontheperformanceverificationofthefacilities.Itshouldbenotedthatdesignshipsvarydependingonperformancecriteriatobeappliedevenforthesamefacilitiesandthattheyarenotalwaystheshipswiththelargestgrosstonnage.

(2)ActionsduetoShipBerthingandtheTractionbyShips①Actionscausedbyshipberthing

Theactionscausedbyshipberthingtomooringfacilitiesshallbeproperlyconsidered.Insettingtheactionscausedbyshipberthing,shipberthingenergycanbecalculatedusingpropermethodsbasedonshipmasses,shipberthingvelocities,virtualmassfactors,eccentricityfactors,flexibilityfactors,andtheberthconfigurationfactors.

②ActionscausedbyshipmovementsTheactionscausedbyshipmotionstomooringfacilitiesshallbeproperlydetermined.Methodstobeconsideredareoscillationcalculationetc.

③ActionsduetothetractionbyshipsThetractioncausedbyshipstomooringfacilitiesshallbeproperlydetermined.Thesettingofthetractionbyshipsproperlytakesaccountoftheactionscausedbymooredandberthedships.

[Technical Note]

1 Principal Dimensions of Design Ships

(1)Designshipsarethose,amongtheshipsexpectingtousethefacilitiesconcerned,whichareassumedtohavethemostsignificanteffectsontheperformanceverificationofthefacilities.Therefore,inthecasewheredesignshipsareidentifiable,theirprincipaldimensionsmaybeused.

–290–


(2)In the case where design ships are unidentifiable in advance such case as the public port facilities, thestandardizedvaluesof tonnages, lengthsoverall, lengthsbetweenperpendiculars,moldedbreadths,andfullloaddraftsbyshiptypeshowninTable 1.1maybeusedforthedesigns.ThestandardvaluesinTable 1.1arepreparedbasedonthestatisticalanalysisofthedimensionsoftheexistingshipswithacoverageratioof75%foreachtonnagecategory.Thedataonthedimensionsofsmallcargovesselsusedforthestandardvaluesvarywidely,hencethedimensionsofsmallcargovesselsshouldbesetusingthevaluesinTable 1.2asreferencesandtakingintoconsiderationthetrendsofshipsinports.Thegrosstonnage,GT,giveninTable 1.1basicallymeans international gross tonnage, but in somecases it refers todomesticgross tonnagedependingon thecharacteristicsofthedatausedforsettingthestandardvalues.Suchcases,wherethegrosstonnage,meansthedomesticgrosstonnage,areclearlyindicatedinTable 1.1.Thetableusesthecommonlyusedtonnage,grosstonnageordeadweighttonnage,ofeachshiptypeastherepresentativeindex. Fig. 1.1showstheprincipaldimensionsusedinthetables.

Length overall (Loa)

Length between perpendiculars (Lpp)Full load water line

After perpendicularMolded breadth (B)

Forward perpendicular

W.L

W..L

Full

load

dra

ft ( d

)

Mol

ded

dept

h

Fig. 1.1 Principal Dimensions of Ships

Table 1.1 Standard Values of the Principal Dimensions of Design Ships

1 General cargo ships

DeadWeightTonnage

DWT(t)

LengthoverallLoa(m)

Lengthbetweenperpendiculars

Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)1,0002,0003,0005,00010,00012,00018,00030,00040,00055,00070,00090,000120,000150,000

678292107132139156182198217233251274292

61758599123130147171187206222239261279

10.713.114.71720.721.824.428.330.732.332.338.74244.7

3.84.85.56.48.18.69.810.511.512.813.81516.517.7


–291–

2 Container ships

DeadWeightTonnage

DWT(t)

Lengthoverall

Loa(m)


Lpp(m)

Moldedbreadth

B(m)

Fullloaddraft

d(m)

Reference:Containercarryingcapacity

(TEU)10,00020,00030,00040,00050,00060,000100,000

139177203241274294350

129165191226258279335

22.027.130.632.332.335.942.8

7.99.911.212.112.713.414.7

500–8901,300–1,6002,000–2,4002,800–3,2003,500–3,9004,300–4,7007,300–7,700

3 Tankers

DeadWeightTonnage

DWT(t)

LengthoverallLoa(m)


Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)1,0002,0003,0005,00010,00015,00020,00030,00050,00070,00090,000100,000150,000300,000

637786100139154166184209228243250277334

57728297131146157175199217232238265321

11.013.214.716.720.623.425.629.134.338.141.342.748.659.4

4.04.95.56.47.68.69.310.412.012.914.214.817.222.4

4 Roll-On Roll-Off (RORO) ships

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraftd

(m)3,0005,00010,00020,00040,00060,000

120140172189194208

110130162174174189

18.921.425.328.032.332.3

5.86.57.78.79.79.7

(3,000,5,000,and10,000GTareinJapanesegrosstonnage)

–292–


5 Pure Car Carrier (PCC) ships

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraftd

(m)3,0005,00012,00020,00030,00040,00060,000

112130135158179185203

103119123150175175194

18.220.621.824.426.731.932.3

5.56.26.87.98.89.310.4

(3,000and5,000GTareinJapaesegrosstonnage)

6 Liquefied Petroleum Gas (LPG) carriers

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraftd

(m)3,0005,00010,00020,00030,00040,00050,000

98116144179204223240

92109136170193212228

16.118.622.727.731.133.836.0

6.37.38.910.812.113.114.0

7 Liquefied Natural Gas (LNG) carriers

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)20,00030,00050,00080,000100,000

174199235274294

164188223260281

27.831.436.742.445.4

8.49.210.411.512.1

8 Passenger ships

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraftd

(m)3,0005,00010,00020,00030,00050,00070,000100,000

97115146186214255286324

88104131165189224250281

16.518.621.825.728.232.332.332.3

4.35.06.47.87.87.88.18.1


–293–

9 Ferries9-1 Short-to-medium distance ferries (navigation distance of less than 300 km in Japan)

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)400700

1,0003,0007,00010,00013,000

567080124141166194

476071116130155179

11.613.214.418.622.724.626.2

2.83.23.54.65.76.26.7

(Allareindomesticgrosstonnage)

9-2 Long distance ferries (navigation distance of 300 km or more in Japan)

GrossTonnageGT(t)

LengthoverallLoa(m)


Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)6,00010,00015,00020,000

147172197197

135159183183

2225.128.228.2

6.36.36.96.9

(Allareindomesticgrosstonnage)

Table 1.2 Reference Values of the Principal Dimensions of Design Ships10 Small cargo vessels

DeadWeightTonnage

DWT(t)

LengthoverallLoa(m)


Lpp (m)

MoldedbreadthB(m)

Fullloaddraftd

(m)500700

5358

4753

9.49.5

3.33.3

(3)Thetableforthestandardvaluesoftheprincipaldimensionsofdesignshipsshowstheprincipaldimensionsofshipsforstepwisetonnagecategories.ThesedimensionsareobtainedfromstatisticalanalysesbyTakahashietal.1),2)withoverallcoverageratioof75%.Someshipsthereforehavelargerdimensionsthanthoseofthesametonnagecategoryshipsgiveninthetable,andsomeothershipswiththetonnagecategorylargerthanthatsetfordesignshipshavedimensionssmallerthanthosegiveninthetable.

(4)Thedataof“LMIUShippingData(2004.1)”3)and“JapaneseRegisterofShips(2004)”4)areusedfordeterminingtheprincipaldimensionsofdesignships.

(5)Tonnage5)Thedefinitionsofthevarioustypesoftonnageareasfollows:

① GrossTonnageThemeasurement tonnage of sealed compartments of a ship, as stipulated in the “Law Concerning the Measurement of the Tonnage of Ships”.

② DeadWeightTonnageThemaximumweight,expressedintons,ofcargothatcanbeloadedontoaship.

③ DisplacementTonnageTheamountofwater,expressedintons,displacedbyashipwhenitisfloatingatrest.

(6)Theregressionequationsforgrosstonnages,GT,anddisplacementtonnages,DSP,areshowninTables 1.3and1.4, 1),2),6)respectively.TheyareapplicableontheconditionthatthecoefficientsofdeterminationR2andthestandarddeviationsσaroundtheregressionequationsaretakenintoconsideration.Theregressionequations

–294–


foreachshiptypeinthetablesareapplicablewithintherangeofthetonnagesshowninTable 1.1.

(7)The container ships of under-panamax, panamax, and over-panamax types have characteristic dimensionspeculiartoeachtype,andhencethesettingoftheirdimensionsmayrefertoTables 1.5to1.9.ThesettingofthedimensionsofverylargecrudeoilcarriermayrefertoTable 1.10.

(8)Theheightsoftheshipsdifferconsiderablyevenincaseofthesametypeandthesametonnage.Theperformanceverificationofbridgesandotherstructurescrossingwaterwaysshouldthereforetakeaccountoftheheightsofdesignshipsfromtheseasurfacetothehighestpoints.TheheightsofshipscanrefertothefindingsofthestudybyTakahashietal.7),8).

Table 1.3 Regression Equations for Dead Weight Tonnages (DWT) and Gross Tonnages (GT) 1), 2)

Shiptype Regressionequation

CoefficientofdeterminationR2

Standarddeviationσ(t)

Generalcargoship GT=0.529DWT 0.988 2,202

Containership GT=0.882DWT 0.971 3,735

Tanker GT=0.535DWT 0.992 4,276

ROROship

InternationalGrosstonnage GT=1.780DWT 0.752 7,262

DomesticGrosstonnage GT=1.409DWT 0.825 1,528

Purecarcarrier(PCC)

InternationalGrosstonnage GT=2.721DWT 0.826 7,655

DomesticGrosstonnage GT=1.241DWT 0.781 676

LPGcarrier GT=0.845DWT 0.988 1,513

LNGcarrier GT=1.370DWT 0.819 12,439

Passengership GT=8.939DWT 0.862 12,285

Mediumdistanceferry GT=2.146DWT 0.833 1,251

Longdistanceferry GT=2.352DWT 0.816 1,988

Table 1.4 Regression Equations for Dead Weight Tonnages (DWT) or Gross Tonnages (GT) and Displacement Tonnages (DSP) 6)

Shiptype Regressionequation Standarddeviationσ

Generalcargoship DSP=1.139DWT 0.052DWT

Containership DSP=1.344DWT 0.060DWT

Tanker DSP=1.138DWT 0.145DWT

ROROship(InternationalGrossTonnage)* DSP=0.880GT 0.211GT

Purecarcarrier(PCC)(InternationalGrossTonnage)* DSP=0.652GT 0.147GT

LPGcarrier DSP=1.114GT 0.425GT

LNGcarrier DSP=1.015GT 0.154GT

Passengership DSP=0.522GT 0.076GT

Mediumdistanceferry DSP=1.052GT 0.337GT

Longdistanceferry DSP=1.150GT 0.135GT

* Onlyinternationalgrosstonnagevaluesareshown.


–295–

Table 1.5 Principal Dimensions of Container Ships (under panamax) 1), 2)

DeadWeightTonnage

DWT(t)

Lengthoverall

Loa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraft

d(m)


(TEU)5,00010,00020,00030,00040,000

109139177203225

101129165191211

17.922.027.030.430.6

6.37.910.011.412.5

300–500630–850

1,300–1,5002,000–2,2002,600–2,900

Table 1.6 Principal Dimensions of Container Ships (panamax) 1), 2)

DeadWeightTonnage

DWT(t)

Lengthoverall

Loa(m)


Lpp(m)

Moldedbreadth

B(m)

Fullloaddraft

d(m)


(TEU)30,00040,00050,00060,000

201237270300

187223255285

32.332.332.332.3

11.312.012.713.4

2,100–2,4002,800–3,2003,400–3,9004,000–4,600

Table 1.7 Principal Dimensions of Container Ships (over panamax) 1), 2)

DeadWeightTonnage

DWT(t)

Lengthoverall

Loa(m)

Lengthbetween

perpendicularsLpp(m)

Moldedbreadth

B(m)

Fullloaddraft

d(m)


(TEU)60,00070,000

80,000–100,000

275/ 285276/ 280300/ 304

260/ 268263/ 266285/ 292

37.2/ 40.040.0/ 40.040.0/ 42.8

12.7/ 13.814.0/ 14.013.5/ 14.5

4,300–5,4005,300–5,6006,300–6,700

* Thistabledoesnotshowtheresultsofstatisticalanalyses,butshowsthe1/4thand3/4thvaluesinascendingorder.

Table 1.8 Principal Dimensions of Container Ships Over 100,000 DWT

DeadWeightTonnage

DWT(t)

Lengthoverall

Loa(m)


Lpp(m)

Moldedbreadth

B(m)

Fullloaddraft

d(m)


(TEU)100,870101,570101,612104,696104,700104,750107,500109,000110,000115,700156,907

324.0334.1334.0346.0346.0346.0332.0352.0336.7366.9397.6

324.0319.0319.0331.5331.5331.5 －336.4321351.1376.0

42.042.842.842.842.842.843.242.842.842.856.0

13.014.514.514.514.514.514.514.515.015.016.5

8,0008,2048,1006,6006,6007,2268,40010,1509,2007,92911,000

* This table is prepared based on “LMIUShippingData (2006.8).”As ofAugust 2006, 100 container ships have atonnageofover100,000DWT. In this table,eachDWTcategoryrepresentsacasewhere thereare threeormoreshipswiththesameDWTcategory,andshowstheprincipaldimensionsoftheshipwiththelargestcontainercarryingcapacityamongthemexceptoneshipof156,907DWT.

–296–


Table 1.9 Principal Dimensions of the Container Ships with a Container Carrying Capacity of Over 8,000 TEU

Containercarryingcapacity

(TEU)

Lengthoverall

Loa(m)


Lpp(m)

Moldedbreadth

B(m)

Fullloaddraft

d(m)

Reference:SelfweightTonnage

DWT(t)

8,0008,0308,0638,1008,1528,1548,1898,2008,2048,2388,4009,2009,4159,60010,15011,000

324.0324.8323.0335.5335.0275.0334.0334.1334.0335.0332.4350.6349.0337.0352.0397.6

324.0–308.0––263.0–314.7319.0319.0317.2336.8353.3–336.4376.0

42.042.042.842.842.837.1–––42.8–42.842.8–42.856.0

13.014.514.514.613.512.514.514.514.511.514.514.514.5–14.516.5

100,870104,90499,615103,80097,61268,363101,906101,818110,00097,430108,180112,062117,800115,000109,000156,907

* Thistableispreparedbasedon“LMIUShippingData(2006.8).”AsofAugust2006,90containershipshaveacapacityofover8,000TEU.Inthistable,eachTEUcategoryrepresentsacasewherethreeormoreshipswiththesameTEUcapacityexist.TheprincipaldimensionsoftheshipwiththelargestDWTamongthemareindicatedinthetableexceptthelargestshipof11,000TEUship.

Table 1.10 Principal Dimensions of Tankers Over 400,000 DWT

DeadWeightTonnage

DWT(t)

LengthoverallLoa(m)


Lpp(m)

MoldedbreadthB(m)

Fullloaddraftd

(m)423,000441,893441,823442,470

380380380380

366366––

68.068.068.068.0

24.524.524.524.5

* Thistableshowsthedataofaparticularship.

References

1) Takahashi,H.,Goto,F.andAbe,M.:Studyonshipdimensionsbystatisticalanalysis-standardofmaindimensionsofdesign(Draft)-NationalInstituteforLandandInfrastructureManagementNo.28,2006

2) Lloyd’sMarineIntelligenceUnite:LMIUShippingData(2004.1),20043) JapanShippingExchange,Inc.:TheAnnual“RegisterofShips”(SENPAKUMEISAISHO)2004,20044) JapanInstituteofNavigation:Glossaryofbasicnavigationterms,Kaibun-doPublishing,19935) Takahashi,H.,A.Goto,M.Abe:StudyonStandardsforMainDimensionsoftheDesignShip,TechnicalNoteofNational

InstituteforLandandInfrastructureManagementNo,309,20066) Yoneyama,H.,Takahashi,H.andGoto,A.:PropositionofPartialFactorsonReliability-BasedDesignMethodforFenders,

TechnicalNoteofPARINo.1115,20067) Takahashi,H.andF.Goto:StudyofshipHeightbystatisticalanalysisstandardofshipheightofdesignship(draft)-Research

ReportofNationalInstituteforLandandInfrastructureManagementNo.31,20068) Takahashi,H.,A.Goto:StudyonShipHeightbyStatisticalAnalysis,ReportofNationalInstituteforLandandInfrastructure

ManagementNo.33,2007


–297–

2 Actions Caused by Ships2.1 General2.1.1 Ship Berthing

(1)Theactionscausedbyberthingshipstomooringfacilitiesshallbedeterminedusingappropriatemethods,takingaccount of the dimensions of design ships, berthingmethods, berthing velocities, the structures of mooringfacilities,etc.

(2)Theactionscausedbyberthingshipstomooringfacilitiesshallincludethosebyshipberthing.Theperformanceverificationofmooringfacilities,ingeneral,shalltakeaccountoftheberthingforcesbyships.

(3)Theberthingforcescausedbyshipstomooringfacilitiescangenerallybecalculatedbasedontheberthingenergyofshipsusingthedisplacement-restoringforcecharacteristicsoffendersystems.

(4)Inthenormalperformanceverificationoffendersystems,ingeneral,theberthingforcesofshipsaredominantactions.Thetypesofdesignships,berthingvelocities,berthingmethodsetc.havesignificanteffectsonberthingforces,andhenceit ispreferablefortheperformanceverificationtothoroughlystudytheconditionsofdesignships.

(5)Ingeneral,theactionscausedbyshipsrarelydominateintheperformanceverificationofmooringfacilities.Inverifyingtheperformanceofoffshoreberthsformooringlargetankersandlargeorecarriers,piledpiersdesignedwithsmallseismicactionsandmooringfacilitiesforshiprefuge,however,theactionscausedbyshipssometimesdominateindesigningthestructure.Carefulattentionshouldbepaidinthesecases.

2.1.2 Ship Motions

(1)Theactionscausedbymooredshipstomooringfacilitiesshallbedeterminedusingappropriatemethods,takingaccountofthedimensionsofdesignships,thestructuresofmooringfacilities,mooringmethods,thecharacteristicsofmooringequipment,andthewinds,wavesandwatercurrentetc.actingondesignships.

(2)Theactionscausedbymooredshipstomooringfacilitiesshallincludethosebyshipmotions.Theperformanceverificationofmooringfacilities, ingeneral,shall takeaccountoftheimpactforcesandtractiveforcesonthemooringfacilitiescausedbythemotionsofmooredships.Themotionsaregeneratedbytheactionofthewaveforces,windpressureforces,andwatercurrentpressureforcesontheships.Inthecasesofthemooringfacilitiesconstructedattheportfacingtheopenseaandexpectingtheinvasionoflongperiodwaves,orconstructedintheopenseaorportentrancesuchastheoffshoreberthsorconstructedforshiprefuge,thewaveforceshaveasignificanteffectsonmooredships.Theseeffectsshallbefullytakenintoconsideration.

(3)Theimpactforcesandtractiveforcescausedbythemotionsofmooredshipscanusuallybeobtainedbymotionsimulationbasedonwaveforces,windpressureforces,watercurrentpressureforces,andthecharacteristicsofmooringequipment.

(4)Thenormalperformanceverificationoffendersystemsshalltakeaccountofnotonlydominatingberthingforcesof ships but also the impact forces caused by themotions ofmoored ships. In the performance verificationofmooringposts, the tractive forcesdue to themotionsofmoored ships causedby thewindpressure forcesareimportant.Theimpactforcescausedbythemotionsofmooredshipsarestronglyaffectedbythetypesofdesign ships,wavecharacteristics, thedisplacement-restoring forcecharacteristicsof fender systemsetc., andwindpressureforcesarestronglyaffectedbythetypesofdesignships,henceitispreferablefortheperformanceverificationtothoroughlystudytheconditionsofdesignships,wavecharacteristics,thestructuresofquaywalls,thecharacteristicsofmooringequipmentetc.

2.2 Actions Caused by Ship Berthing

(1)BerthingEnergyofShip

① Theactionscausedbyshipberthingaregenerallycalculatedfromtheberthingenergyofships.Theberthingenergyofashipcanbecalculatedfromthefollowingequationbyusingthemassoftheship,theberthingvelocityof theship, theeccentricity factor, thevirtualmass factor, theflexibilityfactor,and theberthconfigurationfactor.Thesubscriptk intheequationreferstothecharacteristicsvalue.

(2.2.1)

–298–


where Ef :berthingenergyofship(kNm) Ms :massofship(t) Vb :berthingvelocityofship(m/s) Cm :virtualmassfactor Ce :eccentricityfactor Cs :flexibilityfactor Cc :berthconfigurationfactor

② There are methods of estimating the berthing energy of ships such as statistical methods, methods usinghydraulicmodel tests,andmethodsusingfluiddynamicsmodels inaddition tokineticenergyofmethod.1)However, regarding these alternativemethods, thedatanecessary fordesignare insufficient and thevaluesofthevariousfactorsusedinthecalculationsmaynotappropriatelyproperlygiven.Thus,thekineticenergymethodisgenerallyused.

③ If it is assumed that a berthing shipmoves only in the abeamdirection, then the kinetic energyEs (kNm)becomesequalto 2 2s bM V . However,whenashipisberthingatadolphin,aquaywalloraberthingbeamequippedwithfendersystems,theenergyabsorbedbythefendersystems,i.e.,theberthingenergyEf oftheship,willbecomeEsfconsideringthevariousrelevantfactors,wheref= Cm Ce Cs Cc

(2)MassofShipThemassofshipinthecalculationequationoftheberthingenergyofshipsmeansthefullloaddisplacementoftheship.Equation (2.2.2)mayalsobeusedtoshowtherelationsbetweenthecharacteristicvaluesofthefullloaddisplacements(DT)anddeadweighttonnages(DWT)orgrosstonnages(GT)ofships.Theywerecalculatedastheregressionequationscovering75%ofthetotalstatisticaldataoffullloaddisplacements(DT)withrespecttodeadweighttonnages(DWT)orgrosstonnages(GT),usingtheregressionequationsandstandarddeviationsshowninTable 1.4 Regression Equations for Dead Weight Tonnages (DWT) or Gross Tonnages (GT) and Displacement Tonnages (DSP) in 1. Principal Dimensions of Design Ships. These relationsareapplicablewithintherangeoftonnageshowninTable 1.1.Thesubscriptkintheequationsreferstothecharacteristicvalues.

Generalcargoships DTk=1.174DWTContainerships DTk=1.385DWTTankers DTk=1.235DWTRoll-onroll-off(RORO)ships DTk=1.022GTPurecarcarriers(PCC) DTk=0.751GT LPGcarriers DTk=1.400GTLNGcarriers DTk=1.118GTPassengerships DTk=0.573GTShort-to-mediumdistanceferries(navigationdistanceoflessthan300km) DTk=1.279GTLongdistanceferries(navigationdistanceof300kmormore) DTk=1.240GT

(2.2.2)where

DT :fullloaddisplacementofship(t)GT :grosstonnageofship(GT)DWT :deadweighttonnageofship(DWT)

(3)BerthingVelocity

① It is preferable to determine the characteristic values of the berthing velocities of ships based on actualmeasurementsorreferencesonthepreviousmeasurementsofberthingvelocities,takingaccountofthetypesofdesignships,loadedconditions,thelocationsandstructuresofmooringfacilities,meteorologicalphenomenaandoceanographicphenomena,theusageoftugboatassistanceandtheirsizesetc.

②Whenlargegeneralcargoshipsorlargeoiltankersberth,theycometoastandstilltemporarily,linedupparalleltothequaywallatacertaindistanceawayfromit.Theyarethengentlypushedbyseveraltugboatsuntiltheycomeintocontactwiththequaywall.Whenthereisastrongwindtowardthequaywall,suchshipsmayberthbeingpulledoutwardsagainstwindbythetugboats.Whensuchaberthingmethodisadopted,itiscommontousetheberthingvelocityof10to15cm/sbasedonthepastdesignexamples.

③ Specialshipssuchasferriesandroll-onroll-offshipsandsmallcargoshipsoftenuseberthingmethodsdifferentfromlargeships,assuchthattheyberthbythemselveswithoutusingtugboatsortheyshiftparalleltothefacelinesofquaywallsiftheyareequippedwithboworsternlamps.Theberthingvelocitieshenceshallbecarefullydeterminedbasedonactualmeasurementstakingaccountoftheirberthingmethods.


–299–

④Fig. 2.2.1 showstherelationshipbetweentheshipmaneuveringconditionsandberthingvelocitybyshipsize.2)Ithasbeenpreparedbasedontheempiricaldatacollected.Thisfigureshowsthattheberthingvelocitymustbesethighinsuchcasethatthemooringfacilitiesarenotshelteredbybreakwatersandarebeingusedbysmallships.

0 20 40 60 80

Difficult berthingexposed

Good berthingexposed

Easy berthingexposed

Difficult berthingsheltered

Good berthingsheltered

Berthing velocity (cm/s)

1,000

DT5,000

DT

10,0

00DT

20,0

00D

T

30,0

00D

T,10

0,00

0DT

80,0

00D

T

Diff

icul

ty o

f shi

p m

aneu

verin

g /

moo

ring

faci

litie

s bei

ng sh

elte

red

or n

ot

Fig. 2.2.1 Relationship between Ship Maneuvering Conditions and Berthing Velocity by Ship Size 2)

⑤ According to the study reports 3), 4) onberthingvelocity, theberthingvelocity is usually less than10 cm/sforgeneralcargoships,butonlyinafewcasesareover10cm/s(seeFig. 2.2.2).Theberthingvelocityonlyoccasionallyexceeds10cm/sfor largeoil tankersthatuseoffshoreberths(seeFig. 2.2.3). Evenforferrieswhichberthundertheirownpower,theberthingvelocityinmanycasesislessthan10cm/s.Nevertheless,sincethereareafewcasesinwhichtheberthingvelocityisover15cm/s,duecaremustbetakenwhenverifyingtheperformanceofferryquays(seeFig. 2.2.4).Basedontheabove-mentionedstudyreports,thecargoloadingconditionhasaconsiderableinfluenceontheberthingvelocity.Inotherwords,whenashipisfullyloaded,whichresultsinsmallunder-keelclearance,theberthingvelocitytendstobelower,whereaswhenitislightlyloaded,whichresultsinalargeunder-keelclearance,theberthingvelocitytendstobehigher.

15

10

5

0 10,000 20,000 30,000 40,000 50,000Displacement tonnage DT (tons)

Ber

thin

g ve

loci

ty (c

m/s

)

○…Open type quay×…Wall type quay (sheet pile, gravity types)○…Open type quay×…Wall type quay (sheet pile, gravity types)

Fig. 2.2.2 Berthing Velocity and Displacement Tonnage for General Cargo Ships 3)

–300–


Displacement tonnage DT (10,000 tons)

Ber

thin

g ve

loci

ty (c

m/s

)

15

15 20 25 30

10

10

5

0

Fig. 2.2.3 Berthing Velocity and Displacement Tonnage for Large Oil Tankers 4)

Displacement tonnage DT (tons)

Ber

thin

g ve

loci

ty (c

m/s

) 15

20

10

5

0 2,000 5,000 8,000

:Stern berthing:Stern berthing:Bow berthing:Bow berthing

Fig. 2.2.4 Berthing Velocity and Displacement Tonnage for Longitudinal Berthing of Ferries 3)

AccordingtothesurveybyMoriyaetal.5),theaverageberthingvelocitiesforgeneralcargoships,containerships,andpurecarcarriersareaslistedinTable 2.2.1.TherelationshipbetweenthedeadweighttonnageandberthingvelocityisshowninFig. 2.2.5.Thissurveyalsoshowsthatthelargertheship,thelowertheberthingvelocitytendstobe.Thehighestberthingvelocitiesobservedwereabout15cm/sforshipsunder10,000DWTandabout10cm/sforshipsof10,000DWTorover.

Table 2.2.1 Dead Weight Tonnage and Average Berthing Velocity 5)

DeadWeightTonnage(DWT)

Berthingvelocity(cm/s)

Generalcargoships Containerships Purecarcarriers Allships

1,000class 8.1 – – 8.1

5,000class 6.7 7.8 – 7.2

10,000class 5.0 7.2 4.6 5.3

15,000class 4.5 4.9 4.7 4.6

30,000class 3.9 4.1 4.4 4.1

50,000class 3.5 3.4 – 3.4

Allships 5.2 5.0 4.6 5.0


–301–

15

20

10

5

00 10,000 20,000 30,000 40,000 50,000

General cargo shipsContainer shipsPure car carriers

V (c

m/s

)

Dead Weight Tonnage (DWT )

R=－0.38A=－0.0009B= 66.1Y=AX+B

Fig. 2.2.5 Relationship between Dead Weight Tonnage and Berthing Velocity 5)

⑥ Fig. 2.2.6 shows a berthing velocity frequency distribution obtained from actual measurement records ofberthingvelocitiesatoffshoreberthsusedbylargeoiltankersofaround200,000DWT.Itshowsthatthehighestmeasuredberthingvelocitywas13cm/s. If thedataareassumedtofollowaWeibulldistribution, then thenon-exceedenceprobabilityoftheberthingvelocitybelowthevalueof13cm/swouldbe99.6%.Themeanμ is4.4cm/sandthestandarddeviationσis2.08cm/s.ApplicationoftheWeibulldistributionyieldstheprobabilitydensityfunctionf(Vb)asexpressedinequation (2.2.3):

(2.2.3)

Fromthisequation,theberthingvelocitycorrespondingtotheexpectedprobabilityof1/1000becomes14.5cm/s.Attheoffshoreberthswheretheberthingvelocitieswereactuallymeasured,adesignberthingvelocitywassetateither15cm/sor20cm/s.6)

0 1 2 3 4 5 6 8 9 10

10

50

100

200N

15020

30%

12 13117

40

91 89

53

2017 11 7

1 3

148

185

123

Poisson distribution m = 3Poisson distribution m = 4Weibull distributionNormal distribution

μ=4.41σ=2.08

N=738

V (cm/s)

Fig. 2.2.6 Frequency Distribution of Berthing Velocity 6)

⑦ Small general cargo ships approach to berths by controlling their positions under their ownpowerwithoutassistanceoftugboats.Consequently,theberthingvelocityisgenerallyhigherthanthatoflargerships,andinsomecasesitmayevenexceed30cm/s.Hence,itisnecessarytopayattentiontothis.Forsmallshipsinparticular,itisnecessarytocarefullydeterminetheberthingvelocitybasedonactuallymeasureddata.

–302–


⑧ Incaseswherecautiousberthingmethodssuchasthosedescribedabovearenottaken,orinthecaseofberthingofsmallormedium-sizedshipsunderinfluenceofcurrents,itisnecessarytodeterminetheberthingvelocitybasedonactuallymeasureddataconsideringtheshipdriftvelocitybycurrents.

⑨Somestudiesproposedtheregressionequationsfortheberthingvelocitiesofshipswithrespecttodaedweighttonnages.7),8)Sincetherangesofshiptypesandtonnagestowhichtheregressionequationsofberthingvelocitiesareapplicablearelimited,theresultsoftheabovestudiesshouldbecarefullyused.

(4)VirtualMassFactors

① Virtualmassfactorscanbecalculatedfromthefollowingequations:

(2.2.4)

(2.2.5)

where Cb :blockcoefficient :displacementvolumeofship(m3) Lpp :lengthbetweenperpendiculars(m) B :moldedbreadth(m) d :fullloaddraft(m)

ThecalculationrequirestheuseofthelengthsbetweenperpendicularsLpp,moldedbreadthsB,andfullloaddraftsdofdesignships.ThecaseswheredesignshipsareofastandardshiptypemayusethevaluesshowninTable 1.1 Standard Values of the Principal Dimensions of Design ShipsincludedinCommentary.

②Whenashipberths,theshipwithmassofMsandthewatermassofMwsurroundingtheshipsimultaneouslydecelerate.Accordingly,theinertialforcecorrespondingtothewatermassisaddedtothatoftheshipitself.Thevirtualmassfactoristhusdefinedasinequation(2.2.6).

(2.2.6)

where Cm :virtualmassfactor Ms :massofship(t) Mw :massofthewatersurroundingtheship,addedmass(t)

Ueda9)proposedequation(2.2.4)basedontheresultsofmodeltestsandfieldmeasurements.Thesecondterminequation (2.2.4)correspondstoMw/Msinequation(2.2.6).

(5)EccentricityFactor

① Eccentricityfactorscanbecalculatedfromthefollowingequation:

(2.2.7)

where l :distancefromtheship’scontactpointtothecenterofgravityoftheshipmeasuredparallelto

thefacelineofthemooringfacility(m) r :radiusofrotationaroundtheverticalaxispassingthroughthecenterofgravityoftheship(m)

② Duringtheberthingprocess,ashipisnotalignedperfectlyalongthefacelineoftheberth.Thismeansthatwhentheshipcomesintocontactwiththefendersystems,itstartsyawingandrolling.Thisresultsinthelossofapartoftheship’skineticenergy.Theamountofenergylossbyrollingisnegligiblysmallcomparedwiththatbyyawing.Equation (2.2.7)thusonlyconsiderstheamountofenergylossbyyawing.

③ r/Lpp isafunctionoftheblockcoefficientCb oftheshipandcanbeobtainedfromFig. 2.2.7.10)Alternatively,onemayusethelinearapproximationshowninequation(2.2.8).

(2.2.8)


–303–

where r :radiusof rotation (radiusofgyration); this is related to themomentof inertia Iz around the

verticalaxisoftheshipbytherelationshipIz=Msr2 Cb :blockcoefficient Lpp :lengthbetweenperpendiculars(m)

ThecalculationrequirestheuseofthelengthsbetweenperpendicularsLppofdesignships.Thecaseswheredesign ships areof a standard ship typemayuse thevalues shown inTable 1.1 Standard Values of the Principal Dimensions of Design ShipsincludedinCommentary.

0.30

0.28

0.26

0.24

0.22

0.200.5 0.6 0.7 0.8 0.9 1.0R

adiu

s of g

yrat

ion

in th

e lo

ngitu

dina

l dire

ctio

n ( r

)

Leng

th b

etw

een

perp

endi

cula

rs (L

pp)

Block coefficient Cb

Fig. 2.2.7 Relationship between the Radius of Gyration around the Vertical Axis and the Block Coefficient 9)

④ AsshowninFig. 2.2.8,whenashipcomesintocontactwiththefendersF1andF2beingtheshipclosesttothequaywallatpointP,thedistancelfromthepointofcontacttothecenterofgravityoftheshipasmeasuredparalleltothemooringfacilitiesisgivenbyequation(2.2.9)or(2.2.10) 11); listakentobeL1whenk >0.5andL2whenk <0.5.Whenk =0.5,listakenaswhicheverofL1orL2thatgivesthehighervalueofCeinequation(2.2.7).

A

A

B

Q

B

F1F2

l

P

keLppcosθ

eLppcosθ

θ

LppαLpp

center of gravity

Fig. 2.2.8 Schematic Illustration of Ship Berthing 11)

(2.2.9)

(2.2.10)

where L1：distancefromthepointofcontacttothecenterofgravityoftheshipasmeasuredparallelto

themooringfacilitieswhentheshipcontactswithfenderF1(m)L2：distancefromthepointofcontacttothecenterofgravityoftheshipasmeasuredparallelto

themooringfacilitieswhentheshipcontactswithfenderF2(m) θ•：berthingangle(thevalueofθisgivenasadesigncondition;itisusuallysetsomewhereinthe

rangeof0to10º)

–304–


e：ratioofthedistancebetweenthefenders,asmeasuredinthelongitudinaldirectionoftheship,tothelengthbetweenperpendiculars

α：ratioofthelengthoftheparallelsideoftheshipattheheightofthepointofcontactwiththefendertothelengthbetweenperpendiculars;thisvariesaccordingtofactorslikethetypeofship,andtheblockcoefficientetc.,butisgenerallyintherangeof1/3to1/2.

k：parameterthatrepresentstherelativelocationofthepointwheretheshipcomesclosesttothemooringfacilitiesbetweenthefendersF1andF2;k varies0<k<1,butitisgenerallytakenatk =0.5.

(6)FlexibilityFactorTheflexibilityfactorCsistheratiooftheberthingenergyabsorbedbythedeformationofshiphulltotheberthingenergyoftheship.ThecharacteristicvalueoftheflexibilityfactorCskmaynormallybesetasCsk=1.0,assumingthatthereisnoenergyabsorptionbythedeformationofshiphull.

(7)BerthConfigurationFactorThewatermass compressed between berthing ship andmooring facility behave like a cushion and decreasetheenergytobeabsorbedbyfendersystems.TheberthconfigurationfactorCcneedstobedeterminedtakingaccountofthiseffect.Thisphenomenonisconsideredtorelatetoberthingangles,theshapesofshiphull,under-keelclearances,andberthingvelocities,butonlylimitedquantitativestudiesonthephenomenonhavebeenmade. ThecharacteristicvalueofberthconfigurationfactorCckmaynormallybesetasCck=1.0.

2.3 Actions Caused by Ship Motions

(1)MotionsofMooredShips

① Actionscausedbythemotionsofmooredshipsaregenerallycalculatedbymotioncalculation,byappropriatelysettingwaveforces,windpressureforces,andwatercurrentpressureforces.

② Theshipsmooredtothemooringfacilitiesconstructedintheopenseaorclosetoportentrancesorinportswherelongperiodwavesinvadeandthosemooredinroughweatherarepossibletomovebytheactionsofwaves,winds,andwatercurrents.Thekineticenergygeneratedbythemotionsofmooredshipssometimesexceedstheberthingenergy.Insuchcases,itispreferablefortheperformanceverificationofmooringpostsandfendersystemstotakeaccountofthetractiveforcesandimpactforcesgeneratedbythemotionsofmooredships.12)Intheportsfacingtheopenseainparticular,ithasbeenfrequentlyreportedthatthelongperiodoscillationsofmooredshipscausedbythelongperiodwavesresultedinadifficultywithsmoothcargohandling.13),14)Careshouldbetakeninsuchports.

③ As a general rule, the oscillations of a moored ship should be analyzed through numerical simulation inconsiderationoftherandomvariationsoftheactionsandthenonlinearityofthedisplacement-restoringforcecharacteristics of themooring system. However,when such a numerical simulation of shipmotions is notpossible,orwhentheshipismooredatasystemthatisconsideredtobemore-or-lesssymmetrical,onemayobtainthedisplacementofandloadsonthemooringsystemeitherbyusingfrequencyresponseanalysisforregularwavesorbyreferringtotheresultsofmotioncalculationonafloatingbodymooredatasystemthathasdisplacement-restoringforcecharacteristicsofbilinearnature.15)

④ Thewaveforceactingonashipconsistsofthewave-excitingforceduetoincidentwavesandthewave-makingresistanceforceaccompaniedbythemotionsoftheship.16)Thewave-excitingforceduetoincidentwavesisthewaveforcecalculatedforthecasethatthemotionsoftheshiparerestrained.Thewave-makingresistanceforceisthewaveforceexertedontheshipwhentheshipundergoesamotionofunitamplitudeforeachmodeofmotions.Thewave-makingresistanceforcecanbeexpressedasthesummationoftwofactors,oneisproportionaltotheaccelerationoftheshipandtheotherisproportionaltothevelocity.Theformercanbeexpressedasanaddedmasswhenitisdividedbytheacceleration,whilethelattercanbeexpressedasadampingcoefficientwhenitisdividedbythevelocity.17)Inaddition,thenonlinearfluiddynamicforcethatisproportionaltothesquareofthewaveheightactsontheship,see4.9 Actions on Floating Body and its Motions in Chapter 2.

⑤ Forshipsthathaveablockcoefficientof0.7to0.8suchaslargeoiltankers,theshipcanbereplacedwithanellipticalcylinderforanapproximateevaluationofthewaveforce.18)

⑥ Forbox-shapedshipssuchasworkingcrafts,thewaveforcecanbeobtainedbyassumingtheshiptobeeitherafloatingbodywitharectangularcrosssectionorarectangularprism.

(2)WaveForcesActingonShip

① Thewaveforceactingonamooredshipshallbecalculatedusinganappropriatemethod,consideringthetypeofshipandthewaveparameters.


–305–

② Thewave force actingon amoored ship is calculatedusing appropriate analysismethods such as the stripmethod,thesourcedistributionmethod,theboundaryelementmethod,orthefiniteelementmethod;themostcommonmethodusedforshipsisthestripmethod.

③WaveForcesbytheStripMethod15),16),17),19)

(a)WaveforceofregularwavesactingontheshipThewaveforceactingontheshipisgivenbythesummationoftheFroude-Kriloffforceandthediffractionforce.

(b)Froude-KriloffforceTheFroude-Kriloffforceistheforcederivedfromtheprogressivewavesaroundtheship.Itisgivenbythesummationoftheforceoftheincidentwavesandtheforceofthereflectedwavesfromthequaywall.

(c) DiffractionforceThediffractionforceactingonashipistheforcethatisgeneratedbythechangeinthepressurefieldwhenincidentwavesarescatteredbytheship.Thediffractionforcecanbeestimatedbyreplacingthischangeinthepressurefieldwiththeradiationforce,namelythewave-makingresistanceforcewhentheshipmovesatacertainvelocityonafluidatrest,forthecasethattheshipismovedrelativetofluid.Itisassumedthatthevelocityoftheshipinthiscaseisequaltotherelativevelocityoftheshiptothewaterparticlesintheincidentwaves.Thisvelocityisreferredtoastheequivalentrelativevelocity.

(d)ForceactingontheshipasawholeThewaveforceactingontheshipasawholecanbecalculatedbyintegratingtheFroude-Kriloffforceandthediffractionforceactingonacrosssectionoftheshipinthelongitudinaldirectionfromx=-Lpp/2tox=Lpp/2

④Waveforcesbydiffractiontheory18)Inthecaseofveryfatship,i.e.,ithasablockcoefficientCbof0.7to0.8,therearenoreflectingstructuressuchasquaywallsbehindtheship,andthemotionsoftheshipareconsideredtobeverysmall,thewaveforcecanbecalculatedusinganequationbasedonadiffractiontheory18)byreplacingtheshipwithanellipticalcylinder.

(3)WindLoadsActingonShip

① Thewindloadactingonamooredshipshallbedeterminedusinganappropriatecalculationformula.

② Itispreferabletodeterminethewindloadactingonamooredshipinconsiderationofthetimefluctuationofthewindvelocityandthecharacteristicsofthewinddragcoefficientsinrespectofthecross-sectionalshapeoftheship.

③ Thewindloadsactingonashiparecalculatedfromequations(2.3.1)to(2.3.3)usingwinddragcoefficientsCXandCYintheXandYdirections,respectively,andwindpressuremomentcoefficientCMaroundthemidship.Thesubscriptkintheequationsreferstothecharacteristicvalues.

(2.3.1)

(2.3.2)

(2.3.3)

where CX :winddragcoefficientintheXdirection(bowdirection) CY :winddragcoefficientintheYdirection(sidedirection) CM :windpressuremomentcoefficientaroundmidship RX :X-directioncomponentofwindloadresultantforce(kN) RY :Y-directioncomponentofwindloadresultantforce(kN) RM :momentofwindloadresultantforcearoundmidship(kNm) ρa :airdensity,whichmaybesetasρa=1.23x10-3(t/m3) U :windvelocity(m/s) AT :above-waterbowprojectedarea(m2) AL :above-watersideprojectedarea(m2) Lpp :lengthbetweenperpendiculars(m)

–306–


④ ItispreferabletodeterminethewinddragcoefficientsCX,CY,andCMthroughwindtunneltestsorwatertanktestsondesignships.However,sincesuchtestsrequiretimeandcost,itisacceptabletousethecalculationequationsforwinddragcoefficients21),22)thatarebasedonwindtunneltests20)orwatertankteststhathavebeencarriedoutinthepast.

⑤ Themaximumwindvelocity,10-minuteaveragewindvelocity,maybeusedasthewindvelocityU.

⑥ Sincethewindvelocityvariesbothintimeandspace,itshouldbetreatedasfluctuatingwindinthemotioncalculationofamooredship. Davenport 23) andHino 24)haveproposed the frequencyspectra for the timefluctuationsofthewindvelocity.ThefrequencyspectraproposedbyDavenportandHinoaregivenbyequations (2.3.4)and(2.3.5),respectively.

(2.3.4)

(2.3.5)

where Su( f )：frequencyspectrumofwindvelocity(m2/s) U10：averagewindvelocityatthestandardheightof10m(m/s) Kr：frictioncoefficientforthesurfacedefinedwiththewindvelocityatthestandardheight;on thesea,itisconsideredthatKr=0.003isappropriate. α：powerexponentwhentheverticaldistributionofthewindvelocityisexpressedbyapower law[U∝(Z/10)α]] z：heightabovethesurfaceofthegroundorthewater(m) m：correctionfactorrelatingtothestabilityoftheatmosphere;m istakentobe2incaseofa storm.

(4)WaterCurrentPressureForcesActingonShip

① Thecurrentpressure forcedue towatercurrentsactingona ship shallbedeterminedusinganappropriatecalculationformula.

② CurrentpressureforcecausedbycurrentsfromthebowThecurrentpressureforcedevelopedbetweenashipandcurrentsfromthebowcanbecalculatedfromequation(2.3.6).Thesubscriptkintheequationreferstothecharacteristicvalue.

(2.3.6)

where Rf :currentpressureforce(kN) S :submergedsurfacearea(m2) V :currentvelocity(m/s)

③ CurrentpressureforcecausedbycurrentsfromthesideThecurrentpressureforcecausedbycurrentsfromthesidecanbecalculatedfromequation (2.3.7).Thesubscriptkintheequationreferstothecharacteristicvalue.

(2.3.7)


–307–

where R :currentpressureforce(kN) ρo :densityofseawater(t/m3) C :currentpressurecoefficient V :currentvelocity(m/s) B :under-watersideprojectedareaofship(m2)

④Watercurrentpressureforceconsistsoffrictionalresistanceandpressureresistance.Thecurrentsfromthebowandthesidemostlygeneratefrictionalandpressureresistances,respectively,butthesetworesistancescannotberigorouslydistinguished.Equation (2.3.6)isasimplifiedonesubstitutingρo=1.025t/m3,t=15°C,andρo=0.14intoequation(2.3.8)calledFroude’sformula.Thesubscriptkintheequationreferstothecharacteristicvalue.

(2.3.8)

where Rf :currentpressureforce(kN)ρ0g :unitweightofseawater(kN/m3) t :temperature(°C) S :submergedsurfacearea(m2) V :currentvelocity(m/s) λ :coefficient,whichcanbesetasλ=0.14741foralengthoverallof30mandλ=0.13783fora

lengthoverallof250m.

⑤ ThecurrentpressurecoefficientC variesaccordingtotherelativecurrentdirectionθ ;thevaluesobtainedfromFig. 2.3.1 maybeusedasareference.

1.5

7.0

0 20 40 60 80 100 120 140 160 180

6.0

5.0

4.0

3.0

2.0

1.0

0

Relative current direction θ (º)

Cur

rent

pre

ssur

e co

effic

ient

C

Water depth hdraft d = 1.1

Fig. 2.3.1 Current Pressure Coefficient C

(5)CharacteristicsofMooringSystem

① For themotioncalculationofamooredship, thedisplacement-restoringforcecharacteristicsof themooringsystemsuchasmooringropesandfendersshallbemodeledappropriately.

② Thedisplacement-restoringforcecharacteristicsofthemooringsystemsuchasmooringropesandfendersisgenerallynonlinear.Moreover,thedisplacement-restoringforcecharacteristicsoffendersmaypossesshysterisisnature.Inthatcase,itispreferabletomodelthesecharacteristicsappropriatelyforthemotioncalculationofamooredship.25)

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2.4 Actions due to Traction by Ships

(1)ThevaluesgiveninTable 2.4.1shallgenerallybeusedforthestandardvaluesofthetractiveforcescausedbyshipstomooringpostsandbollards.

(2)Incaseofthemooringpost,itshallbeassumedthatthetractiveforcesbyshipsspecifiedintheItem(1)actinthehorizontaldirection,andthehalfofthetractiveforcesactintheverticaldirectionatthesametime.

(3)Incaseof thebollard, it shallbeassumed that the tractive forcesby ships specified in the Item (1) act in alldirections.

Table 2.4.1 Standard Values of Tractive Forces by Ships

Grosstonnageofship(t)

Tractiveforceactingonmooringpost

(kN)

Tractiveforceactingonbollard(kN)

Over200andnotmorethan500 150 150

Over500andnotmorethan1,000 250 250

Over1,000andnotmorethan2,000 350 250




Over10,000andnotmorethan20,000 1,000 700

Over20,000andnotmorethan50,000 1,500 1,000

Over50,000andnotmorethan100,000 2,000 1,000

(4)Mooringpostsareinstalledawayfromthefacelineofquaywall,aroundthebothendsofaberthsothattheymaybeusedformooringashipinastorm.Bollards,ontheotherhand,areinstalledclosetothefacelineofthemooringfacilitiessothattheymaybeusedformooring,berthing,orunberthingashipinnormaloperations.

(5)Regardingthelayoutandnamesofmooringropesofaship,2.1.1 (1) Dimensions of Wharvesin Part III, Chapter 5 maybereferred.

(6)Regardingthelayoutandstructureofmooringpostsandbollards,see9.1 Mooring Posts and Mooring RingsinPart III, Chapter 5.

(7)Itispreferabletocalculatethetractiveforcesactingonmooringpostsandbollardsbasedonthebreakingloadsofthemooringropesofdesignships,meteorologicalandoceanographicconditionsattheinstallationplacesofmooringfacilities,shipdimensionsetc.,takingaccountasnecessaryoftheforcescausedbyberthingships,thewindpressureforcesactingonmooredships,andtheforcescausedbytheshipmotions.9),15)ThetractiveforcesmayalsobedeterminedaccordingtothefollowingItems(8)to(12).

(8)Incasethatthegrosstonnageofashipexceeds5,000tonsandthereisnoriskofmorethanonemooringropebeingattachedtoabollardthatisusedforspringlinesatthemiddleofmooringfacilitiesforwhichtheberthingshipsaredesignated,thetractiveforceactingonabollardmaybetakenasonehalfofthevaluelistedinTable 2.4.1.

(9)Thetractiveforcesbytheshipsofagrosstonnageoflessthan200tonsormorethan100,000tons,whicharenotgiveninTable 2.4.1,thoseappliedtothemooringfacilitiescapableofmooringshipsinroughweather,andthoseappliedtothemooringfacilitiesinstalledintheopenseaareawheremeteorologicalandoceanographicconditionsareroughneedtobedetermined,takingaccountofmeteorologicalandoceanographicconditions,thestructuresofmooringfacilities,measurementrecordsoftractiveforces,etc.

(10) Thetractiveforceactingonamooringposthasbeendeterminedbasedonthewindpressureforceactingon


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ashipinsuchawaythatalightlyloadedshipshouldbeabletobemooredsafelyevenwhenthewindvelocityis25to30m/s,withtheassumptionthatthemooringpostsareinstalledattheplaceawayfromthefacelineofthequaywallbyaship’swidthandthatthebreastlinesarestretchedinadirectionof45ºtotheship’slongitudinalaxis.26),27)Thetractiveforcesoobtainedcorrespondstothebreakingstrengthofonetotwomooringropes,wherethebreakingstrengthofamooringropeisevaluatedaccordingtothe Steel Ship Regulations by the Nippon Kaiji Kyokai.Forasmallshipofgrosstonnageupto1,000tons,themooringpostscanwithstandthetractiveforceunderthewindvelocityofupto35m/s. Thetractiveforceactingonabollardhasbeendeterminedbasedonthewindpressureforceactingonashipinsuchawaythatevenalightlyloadedshipshouldbeabletobemooredusingonlybollardsunderthewindvelocityofupto15m/s,withtheassumptionthattheropesatthebowandsternarestretchedinadirectionatleast25ºtotheship’saxis.Thetractiveforcesoobtainedcorrespondstothebreakingstrengthsofonemooringropeforashipofgrosstonnageupto5,000tonsandtwomooringropesforashipofgrosstonnageover5,000tons,wherethebreakingstrengthofamooringropeisevaluatedaccordingtothe Steel Ship Regulations by the Nippon Kaiji Kyokai. Thetractiveforceforabollardthatisusedforspringlinesandisinstalledatthemiddleofaberth,forwhichtheberthingshipsaredesignated,correspondstothebreakingstrengthofonemooringrope,wherethebreakingstrengthofamooringropeisevaluatedaccordingtothe Steel Ship Regulations by the Nippon Kaiji Kyokai. Intheabove-mentionedtractiveforcecalculations,inadditiontothewindpressureforce,ithasbeenassumedthattherearewatercurrentsof2ktinthelongitudinaldirectionand0.6ktinthetransversedirection.

(11) Whendeterminingthetractiveforceofasmallshipofgrosstonnageupto200tons,itispreferabletoconsiderthetypeofship,theberthingsituation,thestructureofthemooringfacilities,etc.28)Fortheperformanceverificationofmooringpostsandbollardsforshipsofgrosstonnageupto200tons,itiscommontotakethetractiveforceactingonamooringposttobe150kNandthetractiveforceactingonabollardtobe50kN.

(12)Whencalculatingthetractiveforceincaseofshipssuchasferries,containerships,orpassengerships,cautionshouldbetakeninusingTable 2.4.1,becausethewindpressure-receivingareasofsuchshipsarelarge.

References

1) PIANC:Report of the InternationalCommission for Improving theDesign of Fender Systems, Supplement toBulletin,No.45,1984

2) Baker,A.L.L.:TheImpactofShipsWhenBerthing,Proc.Int'lNavig.Congr.(PIANC),Rome,Sect.II,Quest.2,pp.111-142,1953

3) Mizoguchi,M.andNakayama,T.:StudiesontheBerthingVelocity,EnergyoftheShips,TechnicalNoteofPortandHarbourResearchInstitute,No.170,1973(inJapanese)

4) Otani,H.,Ueda,S.,Ichikawa,T.andSugihara,K.:AStudyontheBerthingImpactoftheBigTanker,TechnicalNoteofPortandHarbourResearchInstitute,No.176,1974(inJapanese)

5) Moriya,Y.,Yoshida,Y.,Ise,H.,Miyazaki,K.andSugiura,J.:FieldObservationsontheBerthingVelocitiesofShips,Proc.ofCoastalEngineering,JSCE,Vol.38,pp.751-755,1991(inJapanese)

6) Ueda,S.:StudyonBerthingImpactForceofVeryLargeCrudeOilCarriers,ReportofPortandHarbourResearchInstitute,Vol.20No.2,pp.169-209,1981(inJapanese)

7) Ueda,S.,Umemura,R.,Shiraishi,S.,Yamamoto,S.,Akakura,Y.andYamase,S.:StudyontheStatisticalDesignMethodforFenderSystem,Proc.ofCoastalEngineering,JSCE,Vol.47,pp.866-870,2000(inJapanese)

8) Ueda,S.,Hirano,T.,Shiraishi,S.,Yamamoto,S.andYamase,S.:ReliabilityDesignMethodofFenderforBerthingShip,Proc.Int'lNavig.Congr.(PIANC),Sydney,pp.692-707,2002

9) Ueda,S.andOoi,E.:OntheDesignofFendingSystemsforMooringFacilitiesinaPort,TechnicalNoteofPortandHarbourResearchInstitute,No.596,1987(inJapanese)

10) Myers,J.:HandbookofOceanandUnderwaterEngineering,McGraw-Hill,NewYork,196911) JapanPortandHarborAssociation:DesignCalculationExamplesofPortandHarbourStructures(Vol.1),pp.117-119,1992

(inJapanese)12) Ueda,S.andShiraishi,S.:OntheDesignofFendersBasedontheShipOscillationsMooredtoQuayWalls,TechnicalNote

ofPortandHarbourResearchInstitute,No.729,1992(inJapanese)13) Shiraishi,S.:Low-FrequencyShipMotionsDuetoLong-PeriodWavesinHabors,andModificationstoMooringSystems

ThatlnhibitSuchMotions,ReportofPortandHarbourResearchInstitute,Vol.37No.4,pp.37-78,199814) CoastalDevelopment InstituteofTechnology:Manual for ImpactAssessmentofLongPeriodWaves inaPort,2004 (in

Japanese)15) Ueda, S.:AnalyticalMethod of ShipMotionsMoored toQuayWalls and theApplications,TechnicalNote of Port and

HarbourResearchInstitute,No.504,1984(inJapanese)16) Motora,S.,Koyama,T.,Fujino,M.andMaeda,H.:DynamicsofShipsandOffshoreStructures-revisededition-,Seizando,

pp.39-121,1997(inJapanese)17) Ueda,S.andShiraishi,S.:MethodandItsEvaluationforComputationofMooredShip'sMotions,ReportofPortandHarbour

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ResearchInstitute,Vol.22No.4,pp.181-218,1983(inJapanese)18) Goda,Y., Takayama, T. and Sasada, T.: Theoretical and Experimental Investigation ofWave Forces on a FixedVessel

ApproximatedwithanEllipticCylinder,ReportofPortandHarbourResearch Institute,Vol.12No.4,pp.23-74,1973 (inJapanese)

19) Kobayashi,M.,Yuasa,H.,Kishimoto,O.,Abe,M.,Kunitake,Y.,Narita,H.,Hirano,M.andSugimura,Y.:AComputerProgramforTheoreticalCalculationofSea-keepingQualityofShips (Part1-MethodofTheoreticalCalculation),MitsuiTechnicalReview,No.82,pp.18-51,1973(inJapanese)

20) Tsuji,T.,Takaishi,Y.,Kan,M.andSato,T.:ModelTestaboutWindForcesActingontheShips,ReportofShipResearchInstitute,Vol.7No.5,pp.13-37,1970(inJapanese)

21) Isherwood,R.M.:WindResistanceofMerchantShips,BulletinoftheRoyalInstitutionofNavalArchitects,pp.327-338,197222) Ueda,S.,Shiraishi,S.,Asano,K.andOshima,H.:ProposalofFormulaofWindForceCoefficientandEvaluationofthe

EffecttoMotionsofMooredShips,TechnicalNoteofPortandHarbourResearchInstitute,No.760,1993(inJapanese)23) Davenport,A.G.:GustLoadingFactors,Proc.ofASCE,ST3,pp.11-34,196724) Hino,M.:RelationshipsbetweentheInstantaneousPeakValuesandtheEvaluationTime-ATheoryontheGustFactor-,

TransactionsoftheJapanSocietyofCivilEngineers,No.117,pp.23-33,1965(inJapanese)25) CoastalDevelopmentInstituteofTechnology:TechnicalManualforFloatingStructures,pp.37-55,1991(inJapanese)26) Inagaki,H.,Yamaguchi,K.andKatayama,T.:StandardizationofMooringPostsandBollardsforWharf,TechnicalNoteof

PortandHarbourResearchInstitute,No.102,1970(inJapanese)27) Fukuda,I.andYagyu,T.:TractiveForceonBollardsandStormBitts,TechnicalNoteofPortandHarbourResearchInstitute,

No.427,1982(inJapanese)28) JapanFishingPortAssociation:StandardDesignMethodforFishingPortStructures,1984(inJapanese)

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 9 ENVIRONMENTAL ACTIONS

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Chapter 9 Environmental Actions

Public NoticeEnvironmental Influences

Article 19Environmental influences shall be assessed with appropriate methods by taking account of the designworkinglifeofthefacilities,materialcharacteristics,environmentalconditions,maintenancemethods,andtheconditionstowhichthefacilitiesconcernedaresubjected.

[Technical Note]

TheevaluationoftheeffectsofenvironmentalactionsmayrefertoPart I, Chapter 2, 3 Maintenance of Facilities Subject to the Technical StandardsandChapter 11, 2.3 Corrosion Protection forsteelandPart III, Chapter 2, 1.1 Generalforconcrete.

chapter 5 earth pressure and water pressurepart ii actions and material strength requirements,...

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