chapter 10 self weight and surcharge

–312–

TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN

Chapter 10 Self Weight and Surcharge

Public NoticeSelf Weight and Surcharge

Article 201 Selfweightshallbeappropriatelysetbasedontheunitweightofthematerial.2Surcharge shallbeappropriately setbyconsidering theassumedusageconditionsof the facilities andothers.

[Technical Note]

1 General

(1)Whenverifyingtheperformanceofportfacilities,selfweightandsurchargeshallbeconsidered,asnecessary.

(2)Selfweightandsurchargearedefinedrespectivelyasfollows.

① Selfweight:theweightofthestructureitself

② Surcharge:theweightloadedontopofthestructure.Thisisdividedintostaticloadandliveload.

(a) StaticloadTheactionssuchasgeneralcargoandbulkcargoloadedonaprons,transitsheds,andwarehousesareincludedinstaticload.Inregionswithheavysnowfall,thesnowontheapronsisregardedalsoasakindofstaticload.

(b)LiveloadThefollowingshallbeconsideredasliveloadasnecessary,whenverifyingtheperformanceofportfacilities.

1) trainload

2) vehicleload

3) cargohandlingequipmentload

4) sidewalkliveload

(3)Theselfweightandsurchargeusedintheperformanceverificationofportfacilitiesmustbesetindueconsiderationofthetypeofactionsontheobjectivefacilitiesandtheirloadingconditions.Inparticular,theselfweightandsurchargehavea largeeffecton theperformanceverificationofcircular slip failureofquaywalls,beamsandslabsofpiers.Therefore,sufficientcareshouldbetakenwhendeterminingthetypesandsizesofselfweightandsurcharge.

2 Self Weight

(1)SelfWeightIntheperformanceverificationofthefacilitiestowhichthetechnicalstandardsapply,theselfweightmustbeappropriatelysetbasedontheunitweightofthematerial.

(2)Asthecharacteristicvaluesoftheunitweightusedinthecalculationofselfweight,thevaluesgiveninTable 2.1 1)maybegenerallyused.However,incaseswheretheunitweightcanbespecifiedinpreliminarysurveyorotherways,thevaluesinTable 2.1arenotalwaysapplicable.

(3)Unitweightsofstone,sand,gravel,andrubbledependonthestonequality,whileunitweightsofmaterialsotherthanmetalssuchassteelandaluminumvaryaccording to individualcases. Whenusing thesematerials, thecharacteristicvaluesforunitweightmustbedecidedwithcare.

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE

–313–

Table 2.1 Characteristic Values of Unit Weights of Materials 1)

Material Characteristicvaluesofunitweight(kN/m3)Steelandcastingsteel 77.0Castingiron 71.0Aluminum 27.5Reinforcedconcrete 24.0Un-reinforcedconcrete 22.6Timber 7.8Asphaltconcrete 22.6Stone(granite) 26.0Stone(sandstone) 25.0Sand,gravel,andrubble(dry) 16.0Sand,gravel,andrubble(wet) 18.0Sand,gravel,andrubble(saturated) 20.0

References

1) JapanPortAssociation:HandbookofConstructionofportfacilities,p,140,1959

–314–


3 Surcharge3.1 Static Load

(1)SurchargeSurchargeusedheremeanstheactionssuchasstaticload,snowload,trainload,vehicleload,cargohandlingequipment load, and sidewalk live load, andwhen setting them it is necessary to appropriately consider theassumedusageconditionsofthefacility.

(2)Characteristicvaluesofsurchargeshallbesetappropriately,consideringtheusageconditionsofportfacilities,suchasthetype,volumeandthehandlingmethodsofthecargohandled.

(3)StaticLoad

① Staticloadinpermanentsituation

(a)Whendeterminingthecharacteristicvaluesstaticloadinpermanentsituations,itispreferabletoadequatelyconsiderthefactorssuchastypeofcargohandled,typeofpacking,volume,handlingmethods,andloadingtime.

(b)Generally,intheperformanceverification,ameanvalueforeachsectioninanapron,ashed,orawarehouseisusedasthestaticload.Howeverintheperformanceverificationofstructuralmaterials,thestaticloaditselfisoftenused.Thestaticloadactingonanapronhasalargeeffectonthestabilityverificationofmooringfacilities,soitisnecessarytoconsideritseparatelyfromthestaticloadsonotherfacilitiessuchasshedsandwarehouses.Foranapron,themeanvalueofthestaticloadperoneblockusuallystaysconstantbythescaleofthemooringfacilityandthetypeofcargohandled,andthemeanvaluemaybedeterminedwithreferencetothepreviousexamplesofverifications.Inthecaseofgeneral-purposewharves,thevaluesfromabout10to30kN/m2areoftenusedasthecharacteristicvaluesofthestaticloadactingonaprons.Asfortheapronswhereheavycargosuchascontainersandsteelishandled,itispreferabletodeterminethevalueofthestaticloadbasedonthestudyofusageconditions.

(c) Thecharacteristicvaluesofunitweightsforbulkcargohavebeenobtainedbasedonsurveysofthepastactualconditions,whicharelistedinTable 3.1.1.1)

Table 3.1.1 Characteristic Values of Unit Weights for Bulk Cargo1)

Commodity Characteristicvaluesofunitweight(kN/m3)

Coke 4.9

Coal(lump) 8.8-9.8

Coal(fine) 9.8-11.0

Ironore 20.0-29.0

Cement 15.0

Sand,gravelandrubble 19.0

② Staticloadduringgroundmotion

(a) It ispreferable todeterminecharacteristicvaluesof the static loadduringgroundmotion invariableandaccidentalsituationsbyadequatelypredictingwhetherastaticloadwillactornotwhenthedesignearthquakeoccurs in future. Existence or nonexistence of a static load differs from the facilities including sheds,warehouses,openstorageyardsandaprons.Itisassumedthatthesizeofthestaticloadduringdesigngroundmotionisundercontrolofaprobabilisticconcept.

(b)Staticloadduringgroundmotionforsheds,warehouses,openstorageandyardsmaybesetaccordingtotheirtypesofusage.Ontheotherhand,forfacilitiessuchasapronsusedascargohandlingfacilitieswherecargoisonlyplacedtemporarily,thestaticloadwillvarytremendouslydependingonwhethercargoloadingoperationsareunderwayornot.MoriyaandNagao2)performedon-sitemeasurementstostudythemoment-to-momentchangeofthestaticloadofbulkcargothatwasloadedonanapron,andevaluatedthedesignvaluesforstaticloadduringgroundmotion.Accordingtotheirresults,ifthedesignvalueforstaticloadduringgroundmotioniscalculatedinaccordancewithISO2394andEurocodes,thevaluebecomes0kN/m2,butadoptionof0kN/m2as thedesignvalue forstatic loadduringgroundmotionresults inunderestimationof thestatic load.2)Therefore,whenusingstatic loadduringgroundmotionfora level1 reliabilitybaseddesignmethod, it ispreferabletoassumethemeanvalueofthestaticloadasthecharacteristicvalueandtomultiplythisvalueby


–315–

thepartialfactor0.5.

③ UnevenlyDistributedLoad

(a)Whenverifyingtheperformanceofastructureasawhole,theunevenlydistributedloadmaybeconvertedtoauniformloadinanareaofanapron,transitshedorwarehouse.However,wherealargeconcentratedloadactsonthestructure,itshouldbeconsideredastheconcentratedload.

(b)Itisnotusuallythecasewherematerialssuchascargoareevenlyloadedovertheentirearea.However,asanexample,whensteelisplacedontimberpillows,itcanbeassumedthatitsweightactsasalineload.Inthiscaseitispreferabletoassumetheweightisaconcentratedloadsuchaslineloadorpointload.

(c)Whenconsideringagivenarea,eventhoughthemeanvalueofunevenlydistributed loadmayfallwithinthevalueofthereplaceduniformload, it isnecessarytotakeaccountofthecasewhereunevenloadactsasaconcentrated load. Forexample, in thecaseofasheetpilequaywall, itmaybedangerous ifa largeconcentratedloadactsonthebackofthequaywall.Similarly,inthecaseofapiledpier,ifaconcentratedloadactsinthecenter,thepiermaybreak.Suchpossibilitiesshouldbeconsideredwhensettingthestaticload.

④ SnowLoad

(a) Afterheavysnowfall,thesnowpileduponanaproniscompactedandhardenedbyautomobiles,andthenitmaybea static load. Therefore it ispreferable to set an appropriate snow load in linewith the actualconditions.

(b)Forquaywallswheresnowremovaloperationswillbecarriedout,itisoftensufficienttodeterminethesnowloadwiththeaccumulatedweightofsnowoveronenight.Inthiscasethesnowloadmaybedeterminedbytheengineertakingintoconsiderationthepastsnowfallrecords,generalclimaticconditionsduringsnowfall,snowqualityandsnowremoval

(c) Inmostcasesthesnowloadissetas1kN/m2.Thisisequivalentto,forexample,approximately70-100cmthicknessofdryandnewpowdersnow.

(d)Therelationshipbetweennormalsnowconditionsandsnowunitweight,describedintheRailway Structure Design Standards and Commentary,3)isshowninTable 3.1.2.

Table 3.1.2 Normal Snow Conditions and Characteristic Value of Unit Weight of Snow 3)

GeneralSnowCondition CharacteristicValueofUnitWeight（kN/m3）Drypowdersnowcompressedunderownweight 1.2Drypoweredsnowsubjecttowindpressure 1.7

Fairlywetsnowcompressedunderownweight 4.5Verywetsnowcompressedunderownweight 8.5

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3.2 Live Load

(1)TrainLoadTrainloadshallbeappliedinsuchawaytoinducethemaximumeffectonthestructuresortheirmembers,bytaking into consideration the netweight, loadedweight, and axle arrangement of the train or carswhich aregenerallyusedfortheobjectivesectionoftrack.Indoingso,trainloadshallbeappliedasafullsetofmultipleloadsinsuccessionwithoutdividingitintotwoormoreseparatesets.

(2)VehicleLoad

① The vehicle load specified here corresponds to that (T load and L load) specified in theHighway Bridge Specifications and Commentary.5)

② TheinternationalregulationsconcerningthedimensionsandmaximumgrossmassofcontainersaresetoutbytheInternational Organization for Standardization (ISO)aslistedinTable 3.2.1.

Table 3.2.1 Standard Dimension of Containers 6)

TypeLength(L) Width(W) Height(H) Rating

(grossmass)

mm Allowancemm ftin Allowance

iin mm Allowancemm ft Allowance

iin mm Allowancesmm ftin Allowance

sin kg lb

1AAA

12,192 0-10 40 0

-3/8 2,438 0-5 8 0

-3/16

2,896* 0-5 96* 0

-3/16

30,480* 67,200*1AA 2,591* 0

-5 86* 0-3/16

1A 2,438 0-5 8 0

-3/161AX <2,438 <8

1BBB

9,125 0-10 29111/4 0

-3/16 2,438 0-5 8 0

-3/16

2,896* 0-5 96* 0

-3/16

30,480* 67,200*1BB 2,591* 0

-5 86* 0-3/16

1B 2,438 0-5 8 0

-3/161BX <2,438 <8

1CC

6,058 0-6 19101/2 0

-1/4 2,438 0-5 8 0

-3/16

2,591* 0-5 86* 0

-3/1630,480* 67,200*1C 2,438 0

-5 8 0-3/16

1CX <2,438 <8

1D2,991 0

-5 993/4 0-3/16 2,438 0

-5 8 0-3/16

2,438 0-5 8 0

-3/16 10,160* 22,400*1DX <2,438 <8

* Somecountriesregulatethetotalheightofthevehicleandcontainer.


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6.06m

6.06m

12.92m

2.44m

2.59

m

2.59

m

2.86

9m3.

93m

3.79

5m

4.01

8m

1) 8' 6'' Flat Bed Chassis

Container Dimensions(Length: 20' ×Width: 8' ×Height: 8' 6'')

Container Dimensions(Length: 20' × Width: 8' ×Height: 8' 6'')

Container Dimensions(Length: 40' ×Width: 8' ×Height: 9' 6'')

3) 9' 6''-40' Specialized Chassis

2) 8' 6'' Low-Bed Chassis

Fig 3.2.1 Tractor-Trailer Height, etc., when Loading a Container

(3)CargoHandlingEquipmentLoad

① General

(a) Cargohandlingequipmentloadisclassifiedintothreetypes:mobile,railmountedandfixedequipment,andtherespectiveactionscangenerallybeconsideredasfollows:

1) Asthecharacteristicvaluesofmobilecargohandlingequipmentload,thetotalselfweight,themaximumwheelload,themaximumloadoftheoutriggeroperation,orthemaximumgroundcontactpressureloadofcrawlerofthemobilecargohandlingequipmentmaybeused.

2) Asthecharacteristicvaluesofrailmountedcargohandlingequipmentload,thetotalselfweightorthemaximumwheelloadconsideringthewheelintervalandnumberofwheelsmaybeused.

3) Asthecharacteristicvaluesoffixedcargohandlingequipmentload,themaximumhoistingloadmaybeused.

(b)Cargo handling equipment continues to grow in size, and it is preferable to appropriately set the designconditionsafterfullystudyingthesizeofcargohandlingequipmentthatisexpectedtobeusedintheobjectivefacilities.

②MobileCargoHandlingEquipmentLoad

(a)Mobile cargo handling equipment includes tire-mounted multi-purpose jib cranes, rough-terrain cranes,all-terrain cranes, tractor cranes, crawler cranes, container cargo handling equipment (including straddlecarriers,transfercranes,frontforklifts,andsiderollers),forklifts,andlogloaders.Machinessuchastire-mountedmulti-purposejibcranesandtractorcranesthatuseanoutriggergivearelativelylargeconcentratedload,soitispreferabletoassumethemostdangerousloadingarrangementfortheperformanceverification. Table 3.2.2showsexamplesofthedimensionsofmulti-purposetire-mountedjibcranes.

(b)ExamplesofthemobilecargohandlingequipmentareshowninFig. 3.2.2to3.2.8 and Tables 3.2.2to3.2.7.

–318–


Table 3.2.2 Examples of Dimensions of Tire-mounted Multi-Purpose Jib Cranes

Type RatedLoad(t)

TotalWeightEquipped

(t)

MainChassisDimensions(m)

MaximumWheelLoadWhenMoving

(kN/wheel)

MaximumGroundContactPressureDuringOperation(*3)(kPa)

Maxi-mumOpera-ting

Radius

TotalWidth(*1)

WheelBase Tread

TotalHeight(*2)

JibCrane

34.0 289 24.0 8.8 8.0 4.0 37.5 217 52734.1 395 30.0 11.0 25.2 3.5 48.0 255 17438.0 349 32.0 11.5 8.5 3.4 51.4 147 88240.0 370 34.0 12.0 9.7 4.3 59.5 320(axleload) 280

DoubleLinkDrawingCrane

34.0 406 30.0 13.0 15.0 5.0 42.5 142 35834.1 402 30.0 12.8 15.0 5.0 45.0 139 30134.5 425 28.0 11.7 10.0 4.5 39.0 294 31437.5 417 32.6 12.0 8.0 5.5 52.0 139 293

Notes: (*1)“Totalwidth”isthetotalwidthofthemovingportion. (*2)“Totalheight”istheheightofthehighestportionofthejibatthesmallestoperatingradius. (*3)“Maximumgroundcontactpressureduringoperation”isthecontactpressureoftheoutriggerduringoperation.

Fig. 3.2.2 Example of a Rough-Terrain Crane

Fig. 3.2.3 Example of an All-Terrain Crane


–319–

Fig. 3.2.4 Example of a Tractor Crane

Table 3.2.3 Examples of Dimensions of Rough-Terrain Cranes, All-Terrain Cranes, and Tractor Cranes

Type MaximumLiftLoad(t)

TotalWeightEquipped(t)

MainChassisDimensions(*1)(m)MaximumAxleLoad(*2)(kN)Total

LengthTotalWidth

TotalHeight

WheelBase Tread

Rough-TerrainCrane

16 19.7 8.23 2.20 3.14 3.20 1.82 97.525 26.5 11.21 2.62 3.45 3.65 2.17 131.235 32.6 11.57 2.75 3.55 3.90 2.24 163.950 37.8 11.85 2.96 3.71 4.85 2.38 185.360 39.6 12.29 3.00 3.74 5.30 2.42 194.4

All-TerrainCrane

100 60.0 13.53 2.78 3.95 6.00 2.32 147.1160 87.5 16.58 3.00 3.98 8.80 2.56 171.6360 90.0 17.62 3.00 4.00 10.24 2.55 154.9400 126.0 18.29 3.00 4.10 11.30 2.56 179.5550 132.0 18.00 3.00 4.25 11.30 2.56 198.1

TractorCrane120 94.7 15.38 3.40 4.00 7.38 2.76/2.52 392.8160 131.4 16.72 3.40 4.05 7.30 2.83/2.54 543.8360 114.0 17.52 3.40 4.34 9.25 2.83/2.54 297.7

Notes: (*1)“Mainchassisdimensions”arethedimensionswhenmovinginsidetheyard. (*2)“Maximumaxleload”isthemaximumvalueoftheaxleloadswhenmovinginsidetheyard

–320–


Fig. 3.2.5 Example of a Straddle Carrier

Table 3.2.4 Examples of Dimensions of Straddle Carriers

MachineName

HandledContainers(ft)

RatedLoad(t)

TotalWeight

Equipped(t)

MainChassisDimensions(m) MaximumOperatingWheelLoad(kN/wheel)

TotalLength(*1)

TotalWidth

TotalHeight

WheelBase

A 20,40 35 60 15.8 4.5 13.6 8.1 117B 20,40 40 59 12.2 5.3 12.6 7.4 122C 20,40,45 35 59 17.4 4.5 13.7 8.0 124Notes: (*1)“Totallength”isthetotallengthwhenhandlinga40-footcontainer.


–321–

Fig. 3.2.6 Example of a Crawler Crane

Table 3.2.5 Examples of Dimensions of Crawler Cranes

LiftLoad(t) TotalWeightEquipped(t)

MainChassisDimensions(m) CrawlerGroundContactPressure

(kPa)TotalHeight CrawlerTotalLength

CrawlerTotalWidth

CrawlerShoeWidth

30 33 4.72 4.49 3.30 0.76 5445 45 5.12 5.40 4.30 0.76 6050 49 5.25 5.57 4.35 0.76 6170 71 6.18 5.99 4.83 0.80 8080 85 6.56 6.32 4.90 0.90 8690 89 6.64 6.40 4.90 0.85 91100 122 7.92 7.88 6.17 0.92 90150 161 8.49 8.49 7.07 1.07 89200 193 8.49 9.18 7.07 1.07 103300 284 9.83 9.76 8.22 1.22 127350 294 7.82 10.14 8.79 1.29 120450 390 10.12 11.51 9.50 1.50 122800 1,190 – 14.68 12.80 2.00 127

–322–


Fig. 3.2.7 Example of a Transfer Crane

Table 3.2.6 Examples of Dimensions of Transfer Cranes

MachineName

HandledContainers(ft)

RatedLoad(t)

TotalWeight

Equipped(t)

MainChassisDimensions(m) MaximumOperatingWheel

Load(kN/wheel)

NumberofWheels(Wheels/Corner)

TotalLength

TotalWidth

TotalHeight

WheelBase

A 20,40 36.0 133 26.1 12.0 21.5 6.4 281 2B 20,40,45 40.6 119 26.0 11.3 21.1 6.4 275 2C 20,40,45 40.6 129 26.3 12.2 21.8 6.4 293 2D 20,40,45 40.6 140 25.8 11.7 24.4 6.4 295 2E 20,40,45 51.0 150 25.8 12.7 28.3 8.0 327 2F 20,40,45 40.6 129 26.0 11.3 21.1 6.4 142 4G 20,40,45 50.0 150 26.0 10.7 21.8 6.4 167 4

③ Rail-MountedCargoHandlingEquipmentLoad

(a) Rail-mountedcargohandlingequipmentincludescontainercranes,pneumaticunloaders,doublelinkluffingcranes,anddoublelinkunloaders.Inthecaseoflargecargohandlingequipmentsuchasgantrycranesandoreunloaders,itisnecessarytoappropriatelyconsideritemssuchastheactionsofseismicmovement,windload,andimpactloadsduringcargohandling.

(b)Fig. 3.2.8 andTable 3.2.7showexamplesofrail-mountedcargohandlingequipment.Fig. 3.2.8andTable 3.2.7, whicharebasedon studiesof the JapanAssociationofCargo-HandlingMachinerySystems, showexamplesofthedimensionsoftypesofrail-mountedcargohandlingequipmentthatareactuallyinuse.


–323–

Top of Sea Side-Facing RailTop of Sea Side-Facing Rail

Fig. 3.2.8 Example of a Container Crane

Table 3.2.7 Examples of Dimensions of Container Cranes

MachineName

HandledContainers

(ft)

RatedLoad(t)

TotalWeightEquipped(t)

MainChassisDimensions(m) MaximumOperatingWheelLoad(kN/wheel)

NumberofWheels(Wheels/Corner)

Out-reach Span Back-

reachTotalWidth

TotalHeight

WheelBase

A 20,40 30.5 580 31.0 16.0 10.0 27.0 68.0 18.0 406 8B 20,40 30.5 627 31.0 16.0 9.0 28.0 72.0 18.0 314 8C 20,40 30.5 668 31.0 16.0 9.5 27.0 46.0 18.0 314 8D 20,40 30.5 635 40.0 16.0 11.0 27.0 80.5 18.0 343 8E 20,40 40.6 1,127 50.0 30.0 15.0 27.0 73.1 18.0 577 8F 20,40,45 40.5 890 47.1 30.0 15.0 28.0 100.0 18.0 558 8G 20,40,45 40.6 965 50.0 30.5 15.0 28.0 102.3 18.0 394 10H 20,40,45 40.6 1,030 50.5 30.0 14.0 26.5 65.0 18.0 720 8I 20,40,45 50.0 993 52.0 30.0 15.0 26.5 105.0 18.0 744 8J 20,40,45 65.0 1,360 63.0 30.0 16.0 26.5 127.2 16.5 711 8

④ StationaryCargoHandlingEquipmentLoadStationarycargohandlingequipmentincludesstationaryjibcranesandstationarypneumaticunloaders.

(4)SidewalkLiveLoadCharacteristicvaluesforsidewalkliveloadmayusuallybe5kN/m2.However,itispreferabletoappropriatelysetthecharacteristicvaluesforspecialkindsoffacilitiesbyconsideringtheusageconditionsofthefacilities.

–324–


References

1) JapanPortAssociation:HandbookofConstructionofportfacilities,p,140,19591) JapanPortAssociation:HandbookofConstructionofportfacilities,pp,303-304,19592) MoriyaY.andT.Nagao:Earthquakeloadsofreliabilitydesignofmooringfacilities,ProceedingsofOffshoreDevelopment

Vol.19,pp.713-718,20033) Railway Technical Research Institute: Standard and commentary of design of railway structures- Concrete structures,

MaruzenPublishing,pp58-59,20044) Railway Technical Research Institute: Standard and commentary of design of railway structures- Concrete structures,

MaruzenPublishing,pp.31-36,20045) JapanRoadAssociation,:SpecificationsandcommentaryforHighwayBridgesPart.I,General,p.p.11-20,pp.82,20046) JapanContainerAssociation:Containerization,No.291,p.15,1996

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS

–325–

Chapter 11 Materials

Public NoticeFundamentals of Performance Verification

Article 3 (excerpts)2TheperformanceverificationofthefacilitiessubjecttotheTechnicalStandardsshallbemadeinprinciplebyexecutingthesubsequentitemstakingintoconsiderationthesituationsinwhichthefacilitiesconcernedwillencounterduringthedesignworkinglife:(1),(2)(omitted)(3)Select the materials of the facilities concerned in consideration of their characteristics and the

environmentalinfluencesonthem,andappropriatelyspecifytheirphysicalproperties.

[Commentary]

CorrosionofSteel:IntheperformanceverificationoffacilitiessubjecttotheTechnicalStandards,appropriatelyconsiderthecorrosionofsteeldependingonconditionssuchasthenaturalenvironment.Ingeneral,steelthatisusedinfacilitiesthataresubjecttotheTechnicalStandardsareplacedunderseverecorrosiveenvironmentalconditions,andappropriatecorrosionprotectionmustbeperformed,usingmethodssuchascathodicprotectionandcovering/coating.

[Technical Note]

1 GeneralSteel used in port facilities shall be selected from appropriate materials taking into account effects on actions,deterioration,workinglifetime,shape,constructability,economyandenvironment.

2 Steel 2.1 General

(1)Steelusedinportfacilitiesmusthavethenecessaryqualitiestosatisfytherequiredfunctionalityofthefacilities.Steel that comply with the Japanese Industrial Standard (JIS) may be given as examples that satisfy suchrequirements. Table 2.1.1andTable 2.1.2listthesteelcomplyingwiththeJapaneseIndustrialStandardthataremostoftenusedinportfacilities.1)Foreachofthem,JISspecifiesmanytypesofsteel.

(2)Ingeneral, structural steelwitha tensilestrengthof490N/mm2ormore iscalledhigh-strengthsteel. High-strengthsteelhasanimportantcharacteristicthatthehigherthestrengthithasthelargerisitsyieldratio,namelytheratiooftheyieldstrengthtothetensilestrength.

(3)Corrosionresistantsteelhasexcellentresistancetoparticlesofseawatersaltabovethesealevel, andtheymaybeeitherWtypeforuncoateduseorPtypeforcoateduse.

–326–


Table 2.1.1 Quality Standards for Steel Materials (JIS) 1)

Typeofsteelmaterial

Standard Symbols Applications

Structuralsteel

JISG3101 Rolledsteelforgeneralstructures SS400 Steelbar,shapedsteel,steelplate,flatsteel,steelstrips

JISG3106 Rolledsteelforweldedstructures SM400,SM490,SM490Y,SM520,SM570

Shapedsteel,steelplate,flatsteel,steelstrips

JISG3114 Hot-rolledatmosphericcorrosionresistingsteelsforweldedstructure

SMA400,SMA490,SMA570 Shapedsteel,steelplate

Steelpipe JISG3444 Carbonsteeltubesforgeneralstructuralpurposes STK400,STK490 –

SteelpileJISA5525 Steelpipepiles SKK400,SKK490 –

JISA5526 SteelHpiles SHK400,SHK400M,SHK490M –

SheetpileJISA5528 Hotrolledsteelsheetpiles SY295,SY390 U-shaped,Z-shaped,H-shaped,flatJISA5530 Steelpipesheetpiles SKY400,SKY490

Castorforgeditems

JISG3201

JISG5101JISG4051

JISG5501

CarbonsteelforgingsforgeneraluseCarbonsteelcastingsCarbonsteelformachinestructuraluseGrayironcastings

SF490A,SF540A

SC450S30CN,S35CNFC150,FC250

Mooringposts,chains,etc

Weldingrods

JISZ3211 Coveredelectrodesformildsteel – SS400,SM400,SMA400

JISZ3212 Coveredelectrodesforhightensilestrengthsteel – SM490,SM490Y,SM520,SMA490

JISZ3351 Submergedarcweldingsolidwiresforcarbonsteelandlowalloysteel – –

JISZ3352 Submergedarcweldingfluxesforcarbonsteelandlowalloysteel – –

JISZ3312 MAGweldingsolidwiresformildsteelandhighstrengthsteel – –

Steelmaterialsusedforjoining

JISB1180 Hexagonheadboltsandhexagonheadscrews – –

JISB1181 Hexagonnutsandhexagonthinnuts – –

JISB1186Setsofhighstrengthhexagonbolt,hexagonnut,andplainwashersforfrictiongripjoints

F8T,F10T –

Wires

JISG3502 Pianowirerods SWRSPiano wire, oil tempered wire, PCsteel and stranded steel wire, wirerope

JISG3506 Highcarbonsteelwirerods SWRH Hardsteelwire,oil temperedwire,PChighcarbonsteelwire,wirerope

JISG3532 Lowcarbonsteelwires SWM –

JISG3536 PCsteelwireandstrandsSWPR1,SWPD1,SWPR2,SWPD3.SWPR7,SWPR19

–

Steelbar

JISG3112 Steelbarsforconcretereinforcement SR235,SR295,SD295A,SD295B,SD345 –

JISG3117 Rerolledsteelbarsforconcretereinforcement

SRR235,SRR295,SDR235 –

JISG3109 PCSteelbars

TypeA2:SBPR785/1030TypeB1:SBPR930/1080TypeB2:SBPR930/1180TypeC1:SBPR1080/1230

–

Notes : AsymbolforsteelmaycomeinvarietiesinJIS,forexample,forSM400therearethreevarietiesSM400A, SM400B,andSM400C,butinthistablethesesymbolsuffixesthatfollowthenumberareomitted. The carbon steel for machine structures, S30CN and S35CN, are obtained from the materials S30C and S35C specified in JIS G 4051byanormalizingheattreatmenttosatisfythemechanicalpropertiesspecifiedintheexplanatoryattachmenttothat standard.


–327–

Table 2.1.2 Shape Specifications for Steel (JIS) 1)

Typeofsteel Standard Materialsused

Structuralsteel

Steelbar JISG3191 SS400

Shapedsteel JISG3192 SS400,SM400,SM490,SM490Y,SM520,SM570,SMA400,SMA490,SMA570

SteelPlateandSteelStrips JISG3193 SS400,SM400,SM490,SM490Y,SM520,SM570,SMA400,SMA490

Flatsteel JISG3194 SS400,SM400,SM490,SM490Y,SM520

SteelpileSteelpipepile JISA5525 SKK400,SKK490H-shapedsteelpile JISA5526 SHK400,SHK400M,SHK490M

SheetpileHotrolledsteelsheetpile JISA5528 SY295,SY390Steelpipesheetpile JISA5530 SKY400,SKY490

Steelmaterialsusedforjoining

Hexagonalheadbolts JISB1180Hexagonalshapenuts JISB1181Setsofhighstrengthhexagonalheadboltsforfrictiongripjoints JISB1186 F8T,F10T

SteelbarSteelbarforreinforcedconcrete JISG3112 SR235,SR295,SD295,SD345Recycledsteelbarforreinforcedconcrete JISG3117 SRR235,SRR295,SDR235

Prestressedconcrete

PCsteelwireandstrands JISG3536 SWPR,SWPDPCsteelbars JISG3109 SBPR,SBPD

Materialsformooring

Wirerope JISG3525 SWRS,SWRHElectricallyweldedanchorchains JISF3303

Wiremesh Weldedwiremesh JISG3551 WFP,WFR,WFI

(4)Whenrolledsteelforgeneralstructures,rolledsteelforweldedstructures,orcorrosionresistanthotrolledsteelforweldedstructuresisused,thicknessmaybechosenfromFig. 2.1.1.2)Whensteelwiththicknesseslessthan8mmare used, follow the standards inSpecifications for Highway Bridges.3) In general, for reasons suchthatsteelwithlargethicknessesrequirealargeamountofcarbonforaspecificstrength,andduringrollingfinecrystallizationmaybeinsufficientandthenotchbrittlenessmaybecomegreater,ausableupperboundforthethicknessisspecifiedinJISforeachsteel.

Thickness(mm)Steeltype 681625324050100

Steelfornon-weldedstructures

SS400

Steelforweldedstructures

SM400ASM400BSM400CSM490ASM490BSM490CSM490YASM490YBSM520C

SM570

SMA400AWSMA400BWSMA400CWSMA490AWSMA490BWSMA490CW

SMA570W

Fig. 2.1.1 Standards for Selecting Thickness Based on the Steel Grade 2)

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(5)StrengthstandardsforPCsteelwireandstrandedPCsteelwirearespecifiedinJIS G 3536,andthestandardsforthechemicalcompositionsofsteelarepresentedinJIS G 3502,Piano Wire.

(6)Infacilitiesthathavemanyweldedportionsforexample,facilitieswithjointconstruction,itisnecessarytopayattentiontothechemicalcompositionandweldabilityofthesteel.Ingeneral,weldedsteelmaterialsuseJIS G 3106,Rolled Steel for Welded Structures,orJIS G 3114,Corrosion Resistant Hot Rolled Steel for Welded Structures. Ontheotherhand,SS400,whichbelongs toJIS G 3101, Rolled Steel for General Structures,shouldbelimitedtonon-weldedportions.

2.2 Characteristic Values of Steel

(1)Characteristicvaluesforvariousconstantsofthesteelandcaststeelrequiredforperformanceverificationareappropriatelyspecifiedbyconsideringfactorssuchasstrengthcharacteristics.

(2)In general, characteristic values for the Young’smodulus, the shearmodulus, Poisson’s ratio, and the linearexpansioncoefficientofsteelandcaststeelcanusethevaluesgivenbyTable 2.2.1.4)Also,theconstantsforsteelusedinreinforcedconcreteandprestressedconcretecanrefertothevaluesgivenintheStandard Specification for Concrete Structures.5)

Table 2.2.1 Mechanical Characteristics for Steel 4)

Young’smodulus E 2.0×105N/mm2

Shearmodulus G 7.7×104N/mm2

Poisson’sratio ν 0.30Linearexpansioncoefficient α 12×10-61/°C

(3)CharacteristicValuesofYieldStrengthCharacteristicvaluesofyieldstrengthforsteelandcaststeelareappropriatelyspecifiedbasedontestresults.

① Structuralsteel

(a) Generally,thevalueslistedinTable 2.2.2canbeusedascharacteristicvaluesofyieldstrengthforstructuralsteelbasedonthegradeofsteelandthethickness.6)


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Table 2.2.2 Characteristic Values of Yield Strength for Structural Steel (JIS) 6)

Typeofsteel

Thicknessmm

TensileyieldstrengthN/mm2

Compressiveonyieldstrength

N/mm2

ShearyieldstrengthN/mm2

Bearingyieldstrengthbetweensteelplateandsteelplate

N/mm2

TensilestrengthN/mm2

SS400

≤ 16 ≥245 ≥245 141 368

400to51016 to 40 ≥235 ≥235 136 35340 to 100 ≥215 ≥215 124 323 ≥ 100 ≥205 ≥205 118 308

SM400SMA400

≤ 16 ≥245 ≥245 141 368

400to510(to540)*1

16 to 40 ≥235 ≥235 136 35340 to 75 ≥215 ≥215 124 32375 to 100 ≥215 ≥215 124 323100 to 160 ≥205 ≥205 118 308160 to 200 ≥195 ≥195 113 293

SM490

≤ 16 ≥325 ≥325 188 488

490to610

16 to 40 ≥315 ≥315 182 47340 to 75 ≥295 ≥295 170 44375 to 100 ≥295 ≥295 170 443100 to 160 ≥285 ≥285 165 428160 to 200 ≥275 ≥275 159 413

SM490YSMA490

≤ 16 ≥365 ≥365 211 548

490to610

16 to 40 ≥355 ≥355 205 53340 to 75 ≥335 ≥335 193 50375 to 100 ≥325 ≥325 188 488100 to 160 ≥305 ≥305 176 458160 to 200 ≥295 ≥295 170 443

SM520

≤ 16 ≥365 ≥365 211 548

520to72016 to 40 ≥355 ≥355 205 53340 to 75 ≥335 ≥335 193 50375 to 100 ≥325 ≥325 188 488

*1:Thefigurewithinparentheses()showsthevalueforSMA400.

(b)ThevonMisesyieldcriteriaareusedtocalculatetheshearyieldstrength.

(c)Whenthecontactmechanismbetweentwosteelisaflatsurfaceagainstaflatsurfaceincludingcylindricalsurfacesandcurvedsurfacesthatarenearlyflat,thebearingyieldstrengthmaybetakenas50%morethanthetensileyieldstress.Ifnecessary,whenthereisaverysmallcontactsurfacebetweenasphericalsurfaceoracylindricalsurface,andaflatsurface,itispossibletousetheHertzformulaintheSpecification for Highway Bridges.7)

② Characteristicvaluesforsteelpileandsteelpipesheetpile

(a) Ascharacteristicvaluesofyieldstressforsteelpileandsteelpipesheetpile,generallythevaluesofTable 2.2.3canbeused,basedonthetypesofsteelsandstresses.8)

Table 2.2.3 Characteristic Values of Yield Strength for Steel Pile and Steel Pipe Sheet Pile (JIS) 8) (N/mm2)

Steelgrade

Typeofstress

SKK400SHK400SHK400MSKY400

SKK490SHK490MSKY490

Axialtensilestress(pernetcross-sectionalarea) 235 315Bendingtensilestress(pernetcross-sectionalarea) 235 315Bendingcompressionstress(pertotalcross-sectionalarea) 235 315Shearstress(pertotalcross-sectionalarea) 136 182

(b)When it is necessary to combine the axial stress and shear stress, yield strengthmay be determined byreferencingthetoSpecifications for Highway Bridges.9)

(c) Bucklingstrengthdependsontheconditionofthememberandisspecifiedappropriatelyduringtheverificationoffacility.

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③ Steelsheetpile

(a) Ascharacteristicvaluesofyieldstrengthforsteelsheetpile,generallythevaluesofTable 2.2.4 canbeused,basedonthetypesofsteelsandstresses.10)

Table 2.2.4 Characteristic Values of Yield Strength for Steel Sheet Pile (JIS) 10)

(N/mm2)Steel

Typeofstress SY295 SY390

Bendingtensilestress(pernetcross-sectionalarea) 295 390Bendingcompressionstress(pertotalcross-sectionalarea) 295 390Shearingstress(pertotalcross-sectionalarea) 170 225

④ Castandforgeditems

(a) Ascharacteristicvaluesofyieldstrengthforcastandforgedstructures,generallythevaluesofTable 2.2.5 canbeused,basedonthetypesofsteelsandstresses.11)

Table 2.2.5 Yield Strength for Cast and Forged Structures (JIS) 11) (N/mm2)

Typeofironsteelmaterial

Typeofstrength

Forgedsteel Caststeel

Steelmaterialsformachinestructures Castiron

SF490A SF540A SC450 S30CN S35CN FC150 FC250

Axialtensilestrength(pernetcross-sectionalarea) 245 275 225 275 305 70 105

Axialcompressionstrength(pertotalcross-sectionalarea) 245 275 225 275 305 140 210

Bendingtensilestrength(pernetcross-sectionalarea) 245 275 225 275 305 70 105

Bendingcompressionstrength(pertotalcross-sectionalarea) 245 275 225 275 305 140 210

Shearingstrength(pertotalcross-sectionalarea) 141 159 130 159 178 54 88

(b)WhencalculationsareperformedwiththeHertzformula,themethodofcalculatingthebearingyieldstrengthfollowstheHighway Bridge Specifications and Commentary.12)

⑤ Yieldstrengthforweldedportionsandsteelmaterialsusedforjoining

(a) Ascharacteristicvaluesofyieldstrengthforweldedportions,thevaluesinTable 2.2.6 canbereferred,basedonthetypesofsteelsandstrength.Whenjoiningsteelofdifferentstrengthsgenerallythevalueforthesteelwithlowerstrengthshallbeused.

Table 2.2.6 Characteristic Values of Yield Strength for Welded Portions (JIS) (N/mm2)

TypeofweldingSteel

Typeofstrength

SM400SMA400 SM490

SM490YSM520SMA490

SM570SMA570

Shopwelding

Full penetration groovewelding

Compressionstrength 235 315 355 450

Tensilestrength 235 315 355 450Shearingstrength 136 182 205 260

Fillet welding, partialpenetration groovewelding

Shearingstrength 136 182 205 260

On-sitewelding 1) Asarule,usethesamevaluesasforfactorywelding.2) Forsteelpipepileandsteelpipesheetpile,use90%ofthefactoryvalue.

(b)Technologiesforon-siteweldinghaveimproved,andadequateexecutionmanagementandqualitycontrolhavebeenachievedon-site,sothaton-siteweldinghasattainedthesamemanagementlevelasfactorywelding,


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andthereforeforyieldstrengthithasbeendecidedthatonecantakethesamevaluesforon-siteweldingasforfactoryweldingcanbetaken,asspecifiedinSpecificationforHighwayBridges13).Inlocationswhereitisdifficulttoverifythattheenvironmentalconditionsaregoodfortheweldingofmaterialssuchassteelpipepileandsteelpipesheetpile,theyieldstrengthforon-siteweldingcanbetakentobe90%ofthevalueforfactorywelding.

(c)Table 2.2.7 liststhecharacteristicyieldstrengthforanchorboltsandpins.

Table 2.2.7 Yield Strength for Anchor Bolts and Pins (N/mm2)

Type TypeofsteelTypeofstress SS400 S35CN

Anchorbolts Shearing 100 133

PinsBending 320 438Shearing 168 235Bearing 353 470

(d)It isassumed that thespecifiedanchorboltsareusedasembedded inconcrete. Sinceconstructionusinganchorboltscanoftenbeinsecure,anditisnecessarytomaintainastrengthbalancewiththeconcretethattheysupport,thecalculationofdesignvaluesshouldsufficientlyincludeanextramarginofsafety.

(e) Sincepinsdonotuseboltholesasinsheetorshapedsteel,andusuallydonotusenotches,thereisnoconcernthat theywill concentrate stress. Also, althoughpinsareoftenverified for shearandbearing, their limitvaluesarenotloweredforshearaccompaniedbysliding.Withtheseconsiderationsinmind,valuesforshearyieldstrengtharespecifiedlargerthanthevalueslistedinTable 2.2.2andTable 2.2.5.

(f)Table 2.2.8 liststhecharacteristicyieldstrengthforfinishedbolts.

Table 2.2.8 Yield Strength for Finished Bolts (N/mm2)

StrengthcategoriesaccordingtoJISB1051

Typeofstress4.6 8.8 10.9

Tensile 240 660 940Shearing 140 380 540Bearing 360 990 1410

2.3 Corrosion Protection2.3.1 Overview

(1)Corrosion protection should be taken into consideration when using steel because of the harsh corrosiveenvironmentalconditions.Severelocalizedcorrosionoccursparticularlyinsectionsimmediatelybelowthemeanlowwaterleveland,therefore,appropriatemeasuresshouldbetaken.

(2)ThedistributionofcorrosionratewithrespecttothedepthofsteeldrivenintotheseagenerallyisshowninFig. 2.3.1.16) Thecorrosion isparticularlyheavy in the splash zone,where the structure is exposed to seawatersplashesandthereisanadequatesupplyofoxygen.Inparticular,therateofcorrosionisthehighestinthesectionimmediatelyabovethehighwaterlevel. AmongthesubmergedsectionsinFig. 2.3.1,thecorrosionrateisthehighestinthesectionimmediatelybelowtheintertidalzone.However,thecorrosionrateinthissectiondiffersgreatlydependingontheenvironmentalconditions and the cross-sectional shape of the structure. In steel sheet piles and steel pipe pile structuressubmerged in clean seawater, the corrosion rate in the section immediatelybelow themean lowwater level,MLWL,isoftennotmuchdifferentfromthatinsubmergedzone.Dependingontheenvironmentalconditionsofthestructure,however,thecorrosionrateinthesectionimmediatelybelowMLWLmaybemuchlargerthanthatinthesubmergedzone,andinsomecasesmayevenexceedthevalueinthesplashzone.Thisremarkablelocalcorrosioniscalledtheconcentratedcorrosion.

(3)Forallaspectsofcorrosioncontrol,referencemaybemadeto“Manual on Corrosion Prevention and Repair for Port and Harbor Steel Structures (revised edition)”15)publishedbytheCoastalDevelopmentInstituteofTechnologyinJapan.

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Corrosion rate

Sea bottom

Marine atmospheric zone

Splash zone

H.W.L

L.W.LIntertidal zone

Submerged zone

Under seabed

Fig. 2.3.1 Distribution of Corrosion Rates of Steel Structures 15)

2.3.2 Corrosion Rates of Steel

(1)Thecorrosionrateofsteelshallbedeterminedasappropriateinviewoftheenvironmentalconditionsofthesitewherestructuresareplacedbecausethecorrosionratedependsonthecorrosiveenvironmentalconditions.

(2)The corrosion rate of steel used in port and harbor structures is influenced by the environmental conditionsincluding theweatherconditions, thesalinityandpollution levelof theseawater, theexistenceofriverwaterinflow,etc.Therefore,thecorrosionrateshouldbedeterminedbyreferringtopastcasesinthevicinityandsurveyresultsundersimilarconditions.

(3)ThecorrosionrateofsteelshouldgenerallybedeterminedbyreferringtothestandardvalueslistedinTable 2.3.1,whichhasbeencompiledonthebasisofsurveyresultsontheexistingsteelstructures.However,thevaluesinTable 2.3.1 aretheaverageones,andtheactualcorrosionratemayexceedthemdependingontheenvironmentalconditionsofthesteelmaterial.Therefore,whendeterminingthecorrosionrateofsteel,theresultsofcorrosionsurveysundersimilarconditionsshouldbereferredto.ItshouldalsobenotedthatthevaluesinTable 2.3.1 refertothecorrosionrateforonlyonesideofthesteelsection.Thus,whenthebothsidesofsteelsectionaresubjecttocorrosion,thesumofthecorrosionratesofthebothsidesestimatedonthebasisofthevaluesinTable 2.3.1 shouldbeemployed.

(4)Thevaluesfor“HWLorhigher”inTable 2.3.1 refertothecorrosionrateimmediatelyaboveHWL.ThecorrosionratebetweentheHWLandtheseawatersectionsshouldbedeterminedbyreferringtoactualcorrosionratesinthepropertiesofseawateraroundthestructures. Thisisbecausepastcorrosionsurveyshaveshownthatthecorrosionratevariesdependingonthepropertiesofseawaterandthedepthofwater.ThevaluesinTable 2.3.1 arelistedasreferenceswitharangeofvariation.Ingeneral,thecorrosionintheintertidalzoneshouldbedealtwithseparatelyfromthatinthesubmergedzonebecauseofthedifferencesintheenvironmentalconditions.Theappropriateboundarybetweenthemisaround1.0mbelowLWL. Incasesoftheconcentratedcorrosion,thecorrosionrategreatlyexceedsthevalueslistedinTable 2.3.1,andthusthesevaluesarenotapplicabletosuchcases.

(5)Inoxygen-isolatedspacessuchastheinsideofsteelpipepiles,itmaybeassumedthatcorrosioncannotoccurbecausethereisnosupplyofoxygen.


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Table 2.3.1 Standard Values of Corrosion Rates for Steel 15)

Corrosiveenvironment Corrosionrate(mm/year)

Seaside HWLorhigher

HWL–LWL-1mLWL-1m–seabed

Underseabed

0.30.1–0.30.1–0.20.03

Landside Abovegroundandexposedtoair

Underground(residualwaterlevelandabove)Underground(residualwaterlevelandbelow)

0.10.030.02

(6)Sandabrasionisaphenomenoninwhichtherustlayeronthesteelsurfaceisremovedbythemovementofsandtoexposethebaresteelandtoresultinincreasingthecorrosionrate.17)Thereareexampleswheresteelsheetpilewasusedasasedimentcontrolgroinandthemeancorrosionrateduetosandcorrosiondirectlyabovethesandsurfacewasfrom1.25to2.39mm/year.18)Whentheverticalmotionofthesandsurfaceissmall,thesectionsofabrasionarelimitedtoareasimmediatelyabovethesandsurfaceandsoitissaidthatthecorrosionratesbecomelargerinthesesections.

2.3.3 Corrosion Protection Methods

(1)Corrosionprotectionmethodsforsteelshallbeundertakenasappropriatebyemployingthecathodicprotectionmethod, thecovering/coatingmethod,orothercorrosionpreventionmethod,dependingon theenvironmentalconditions inwhich the steelmaterial exists. For the sections below themean lowwater level, the cathodicprotection shall be employed. For the sections above the depth of 1.0m belowL.W.L., the covering/coatingmethodshallbeemployed.

(2)Intheintertidalzoneandsubmergedzone,thereisariskofconcentratedcorrosion,dependingonthecorrosiveenvironmental conditions. Therefore, in principle, corrosion protection bymeans of the thickness allowanceshouldnotbeundertakenasacorrosionprotectionmethodforsteelstructuresinJapan.However,inthecaseoftemporarystructures,itisacceptabletoemploythecorrosionallowancemethodascorrosionprevention.

(3)Thebackfilling sideof steel sheet pile has a slower corrosion rate than that of the seaward side, and thusnocorrosionprotectionisrequired inparticular. Incaseswhereastronglycorrosiveenvironment isconjectureddue to the influence ofwastematerial in the backfill, however, surveys should be conducted in advance andappropriatemeasuresshouldbetaken.

(4)Forthemosteffectiveactualcorrosionprotection,thecovering/coatingmethodisusedforsectionsabove1mbelowL.W.L.,whilecathodicprotectionisusedforsubmergedsectionsbelowM.L.W.Landforsectionsintheseabottomsoil,andtheirreliabilityhasbeenverified.Whenthecovering/coatingmethodisusedunderwateritisnecessarytopayattentiontodurabilitywhenselectingthecovering/coatingmaterialandtowatchfordamage,suchasduringconstructionorfromcollisionswithdriftwood.Incaseswherethecovering/coatingisusedbothintheairovertheseaandinsectionswithinthewater,whilethecathodicprotectionisusedintheseabottomsoil,ifamargintoestimatethedegradationanddamageofthecovering/coatingmaterialisspecifiedfortheperformanceverificationofthecathodicprotectionandthencathodicprotectioncancompensatethedegradedanddamagedpartsoftheportionsthatusecovering/coatingprotection.

2.3.4 Cathodic Protection Method

(1)RangeofApplication

① TherangeofapplicationofthecathodicprotectionshallinprinciplebeatorbelowM.L.W.L.

② AbovetheMLWL,corrosioncontrolmustbecarriedoutbycovering/coating.ThezonebetweenM.L.W.LandtheL.W.L.issubmergedforashortertimethanthatbelowL.W.L.,andthusthecorrosionrateisslightlylower.Also,becausethesectionsimmediatelybelowL.W.L.aresusceptibletocorrosion,thecovering/coatingshouldextendtoacertaindepthbelowL.W.L.andshouldbecombinedwiththecathodicprotection.

③ Duringportconstructiontheremaybeaperiodwithnocorrosionprotectionaftersteelpipepileandsteelsheetpilehavebeendriveninandbeforethesuperstructurehasbeenconstructed,andtheremaybeperiodsofnocorrosionprotectionwhen theanodesusedforcathodicprotectionarereplaced. Duringsuchperiodsofnocorrosionprotectionthesteelmayhavebeenexposedtoconcentratedcorrosion,sosufficientcareshouldbetaken.

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④ AslistedinTable 2.3.2,theeffectofthecathodicprotection,thecorrosionrateincreaseswhentheperiodofimmersionofthesteelsubjecttocorrosioninseawaterislongeranddecreaseswhenitisshorter.Theseawaterimmersionratioandthecorrosionrateareexpressedinequation(2.3.4)and(2.4.5),respectively.

(2.3.4)

(2.3.5)

Table 2.3.2 Corrosion Control Ratio of the Cathodic Protection Method

Seawaterimmersionratio(%) Corrosioncontrolratebelow40% below40%

equaltoorgreaterthan40%butbelow80% equaltoorgreaterthan40%butbelow60%equaltoorgreaterthan80%butbelow100% equaltoorgreaterthan60%butbelow90%

100% equalto90%orover

⑤ Ingeneral,90%isusedforthestandardcorrosionefficiencyratefortheareabelowM.L.W.L.

⑥ Thecathodicprotectionisdividedintoagalvanicanodemethodandaimpressedcurrentmethod.Underthegalvanicanodesmethod,aluminum(Al),magnesium(Mg),zinc(Zn)andotheralloyareelectricallyconnectedtothesteelstructureandtheelectriccurrentgeneratedbythedifferenceinpotentialbetweenthetwometalsisusedasacorrosionprotectioncurrent.ThismethodisappliedalmostuniversallyincathodicprotectionofportsteelstructuresinJapan,mainlybecauseofeaseofmaintenance.ThecharacteristicsofthegalvanicanodematerialsarelistedinTable 2.3.3.Aluminumalloyanodesofferthehighestfluxofcurrentgeneratedperunitofmass, areoutstandingly economical, and are suited toboth the seawater zone and seabedenvironments.Therefore,aluminumalloyanodesaremostcommonlyusedforportsteelstructures. Undertheimpressedcurrentmethod,anelectrodeisconnectedtothepositivepoleofanexternalDCpowersourceandthesteelstructureisconnectedtothenegativepole.Thenaprotectivecurrentisappliedtowardsthesteelstructurefromthecurrentelectrode.Inseawater,aplatinumoroxidecoatingelectrodeisoftenusedastheworkingelectrode.Sincetheoutputvoltagecanbearbitraryadjustedwiththeimpressedcurrentmethod,itcanbeappliedtotheenvironmentsfeaturingpronouncedfluctuationssuchasstrongcurrentsortheinflowofriverwater,andtheplaceswhereafinepotentialcontrolisrequired.

Table 2.3.3 Characteristics of Galvanic Anode Materials 15)

Characteristics Al-Zn-In PureZn,Znalloy Mg-Mn Mg-6Al-3Zn

SpecificgravityOpencircuitanodevoltage(V)(SCE)Effectivevoltagetoiron(V)Theoreticalgeneratedelectricityflux(A·h/g)

2.6–2.81.080.252.87

7.141.030.200.82

1.741.560.752.20

1.771.480.652.21

Inseawaterwith1mA/cm2

Generatedelectricityflux(A·h/g)Consumedamount(kg/A)/year

2.303.8

2.603.4

0.7811.8

1.108.0

1.227.2

Insoilwith0.03mA/cm2

Generatedelectricityflux(A·h/g)Consumedamount(kg/A)/year

1.86*4.71

0.5316.5

0.8810.0

1.117.9

Note)*Fluctuatesdependingonmaterialcomposition.

⑦ In thegalvanicanodemethod, theattachmentof theanode to thesteelmaterial isusuallyaccomplishedbyunderwaterwelding.Therehavebeenreportsonthesteelsheetpilequaywallswheretheunderlyingsoilbecameliquefiedduringanearthquakesothatanexcessiveamountofsoilpressureacteduponthesteelsheetpileandtheportionthathadbeenweldedunderwatersufferedbrittlefracture.15)Therefore,preventativemeasuresshouldbeapplied,suchas(1)modifyingthechemicalcompositionofsteelsheetpiletoadaptittounderwaterwelding,or(2)beforedrivinginthesheetpile,whilestillonland,weldingacoverplateofsteelappropriateforweldingtotheportionwheretheanodewillbeattached,andthenweldingtheanodetothecoverplateunderwater.


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(2) ProtectivePotential

① Ingeneral,theprotectivepotentialofportsteelstructuresshallbe-780mVvs.Ag/AgCl(seaw)electrode.

②Whenapplyingaprotectivecurrentthroughasteelstructurebythecathodicprotectiontechnique,thepotentialof thesteelstructuregraduallyshifts toa lowlevel. Whenit reachesacertainpotential,corrosion is tobeprotected.Thispotentialisknownastheprotectivepotential.

③ Tomeasure the potential of steel structures, an electrode that indicates stable reference values even in thedifferentenvironmentalconditionsshouldbeusedasthereference.Theelectrodethatprovidesthestandardvalue isknownas the referenceelectrode. In seawater, inaddition to theAg/AgClelectrode, the saturatedmercurouschlorideelectrodeandthesaturatedcoppersulfateelectrodearesometimesused.Thevalueoftheprotectivepotentialdiffersdependingonthereferenceelectrodeusedformeasurement,asinthefollowing:

Seawater-silver/silver-chlorideelectrode; -780mVSaturatedmercurouschlorideelectrode; -770mVSaturatedcoppersulfateelectrode; -850mV

④Whencombiningthecovering/coatingandcathodicprotectionmethods,particularlywiththeimpressedcurrentmethod,careshouldbetakennottoletthecoatingfilmdeteriorateduetoexcessivecurrent.Thepotentialinthiscaseshouldideallybe-800to-1,100mVvs.Ag/AgClelectrode.

(3) ProtectiveCurrentDensity

① Protectivecurrentdensityshallbesettoanappropriatevaluebecauseitvariesgreatlydependingonthemarineenvironment.

②Whenapplyingthecathodicprotection,acertaincurrentdensityperunitsurfaceareaofthesteelisneededinordertopolarizethepotentialofthesteeltoamorebasevaluethantheprotectivepotential.Thisdensityisknownastheprotectivecurrentdensity.Thevalueofthisprotectivecurrentdensitydecreaseswiththeelapseoftimefromtheinitialvalueatthestartofcathodicprotection,andfinallyreachesaconstantvalue.Theconstantvalueisaround40%to50%oftheinitialvalue.

③ Theprotectivecurrentdensityvarieswith temperature, currents,waves, andwaterquality. Where there isaninflowofriverwaterorvariousdischarges,orwherethereisahighconcentrationofsulfides,therequiredprotectivecurrentgenerallyincreases. Also,wherethewatercurrent isfast, therequiredprotectivecurrentincreases.Whenverifyingperformance,theperformanceoftheexistingfacilitiesintheareashouldbereferredtoforcharacteristicvaluesettings.

④ TheprotectivecurrentdensityatthestartofcathodicprotectionshouldbebasedonthestandardvalueslistedinTable 2.3.4 forthebaresteelsurfaceinnormalseaconditions.

⑤ Asthedurationofprotectiongoeson,thegeneratedcurrentweakens.Therefore,theaveragegeneratedcurrentdensityforcalculatingthelifetimeoftheanodeisoftentakenasthefollowing,dependingonthedurationofprotection:

Whenprotectedfor5years; 0.55xinitialgeneratedcurrentdensityWhenprotectedfor10years; 0.52xinitialgeneratedcurrentdensityWhenprotectedfor15years; 0.50xinitialgeneratedcurrentdensity

Iftheprotectionisintendedtolastformorethan15years,thevaluefor15yearsshouldbeapplied.

⑥ Ifaportioncoveredwithprotectivematerialexistswithintherangeofapplicationofcathodicprotection,thevalueof theprotectivecurrentdensity shouldbesetbyassumingacertain rateofdamage to thecovering/coatingmaterial.Inseawaterthefollowingvaluesmaybeset:

Paint; 20+100S (mA/m2)Concrete; 10+100S (mA/m2)Organiccoating; 100S (mA/m2)

whereS is therateofdamagedefinedas theratioofassumeddamagedcoveredareato thetotalcoveredarea. However,iftheprotectivecurrentdensityobtainedfromtheaboveequationexceedsthevaluesindicatedin⑤valuesinTable 2.3.4maybeemployed.

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Table 2.3.4 Protective Current Density at Start of Cathodic Protection (mA/m2) 15)

Cleanseaarea PollutedseaareasInseawater

InrubblemoundInsoil(belowseabed)Insoil(aboveseabed)

100502010

130-15065-7526-3010

2.3.5 Covering/Coating Method

(1) RangeofApplication

① Itisbettertoapplythecovering/coatingmethodtothesectionsinportsteelstructures,wherethedurationofseawaterimmersionisshortbecausethecathodicprotectioncannotbeappliedtothem. As described in2.3.4 Cathodic Protection Method, the range of application of the cathodic protectionmethod isdesignatedasbelowM.L.W.L. However,concentratedcorrosion is liable tooccur in thevicinityofM.L.W.L.,whilethedurationof immersioninseawater isshortenedbytheeffectsofwavesandseasonalfluctuationsintidelevels.Therefore,thecovering/coatingmethodshouldbeappliedincombinationwiththecathodicprotectiontothesectionsabovethedepthof1mbelowL.W.L.

② Insteelsheetpilerevetments inshallowseaareas, thecovering/coatingmethodissometimesappliedto thewholelengthofthestructuredepthwise.Bycombiningthecathodicprotectionandcovering/coatingmethodsinseawatersections,thelifeofthegalvanicanodemaybeextended.15)

(2) ApplicableMethods

① Thecovering/coatingmethodappliedtoportsteelstructuresshallbeoneofthefollowingfourmethods:

(a) Painting

(b)Organiccovering/coating

(c) Petrolatumcovering/coating

(d)Inorganiccovering/coating

② Thecovering/coatingprotectionmethodbasicallycontrolscorrosionbyblockingthecovered/coatedmaterialfromcorrosiveenvironmentalfactors.Theapplicablerangeforthecovering/coatingprotectionmethoddependsonthetype,sothattherearesomemethodsthatapplymainlytotheintertidalzone,thesplashzone,andtheatmosphericzone,andthereareothermethodsthatapplyintheseawater.Intheseawater,thecovering/coatingmethodmaybeusedtogetherwiththecathodiccorrosionprotection,orcoatingcorrosionprotectionmaybeusedalone.Moreover,somemethodsareonlyapplicabletonewfacilitiesandothermethodsareapplicabletonotonlynewfacilitiesbutalsoexistingfacilities.

(3)SelectionofMethodsWhen selecting the covering/coating protection method and determining the specification it is necessary toinvestigateeachofthefollowingitems:

(a) Environmentalconditions

(b)Rangeofcorrosionprotection

(c) Designworkinglife

(d)Maintenanceplan

(e) Constructionconditions

(f) Constructionduration

(g)Corrosionstateanddegradationofexistingcovering/coatingmaterial

(h)Initialdesignconditions

(i) OthersTheaboveg)andh)areonlyapplicabletoexistingstructures.


–337–

References

1) JapanStandardAssociation:JISHandbook,IronandSteelI,II,JapanIndustrialStandards,20022) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.111,20043) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.153,20044) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.I,General,p.p.59,pp.82,20045) JSCE:StandardSpecificationsforConcreteStructures,Structuralperformanceverification,pp.38-44,20026) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.116,20047) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.136-141,20048) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.I,General,p.p.71,20049) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.151-180,200410) JapanStandardAssociation:JISHandbook,IronandSteelPartIandII,JapanStandard,200211) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.I,General,p.73,200712) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.II,SteelBridge,p.136-141,200413) JapanRoadAssociation:SpecificationsandCommentaryforHighwayBridgesVol.I,General,200414) JapanStandardAssociation:JISHandbook,ScrewPartI,JapanStandard,200215) CoastalDevelopmentInstituteofTechnology:Manualforcorrosionprotectionandmaintenanceworkforportsteelfacilities,

ironslughydrationhardener(revisedEdition),200,16) H.A.Humble:Thecathodicprotectionofsteelpilinginseawater,Corrosion,Vol.5No.9,p.292,194917) Abe,M.,T.Fukute,K.ShimizuandI.Yamamoto:Effectofcathodiccorrosionprotectionagainstsanderosioninwavysea

area.,Proceedingof42ndopenforumoncorrosionandcorrosionprotection,C-203,pp.371-374,199518) C.W.Ross:DeteriorationofsteelsheetpilegroinsatPalmBeach,Florida,Corrosion,Vol.5No.10,pp.339-342,1949

–338–


3 Concrete3.1 Materials of ConcreteTheconstituentmaterialsofconcreteandtheirspecialcaretakenforportfacilitiesareasfollows;

(1)Cement

(2)Water

(3)Additiveagent

(4)Admixture

(5)Aggregate

(6)InitialChlorideIonContentToreducetheriskofcorrosionofsteelinsidetheconcrete,theamountofchlorideioncontainedinfreshconcreteshouldbenomorethan0.30kg/m3.

(7)AlkaliAggregateReactionPreventionMeasuresTo prevent alkali aggregate reactions it is necessary tomake appropriate choices among the following threepreventativemeasures:

① ControllingthetotalamountofalkaliwithintheconcreteUseamaterialsuchasPortlandcementforwhichthetotalamountofalkaliisknownandverifythatthetotalamountofalkaliwithintheconcreteisnomorethan3.0kg/m3.

② UsingmaterialssuchasblendedcementUseacementthatcontrolsalkaliaggregatereactions,suchastypeBortypeCblastfurnaceslagcementortypeBortypeCflyashcement.

③Methodsthatuseaggregatesknowntobesafeagainstalkaliaggregatereaction

(8)Ofthevarioustypesofcement,thosehavinggoodseawaterresistancecharacteristicsaresaidtobethemoderateheatportlandcement,blast-furnaceslagcement,andflyashcement.Theadvantagesofthesetypesofcementarethattheyhaveexcellentperformanceindurabilityagainstseawater,greatlypromotelong-termstrength,andhavelowhydrationheat.However,theyalsohavethedisadvantageasrelativelylowinitialstrength.Therefore,whenusingthesetypesofcement,allduecareneedstobegiventoinitialcuring. The anti-corrosion properties of steel reinforcement in concrete producedwith typeB blast furnace slagcementisbetterthanconcretemadewithordinaryPortlandcement1).Inthiscase,itisimportanttoperformasufficientinitialcareofconcrete.

(9) Seawatermustnotbeusedasmixingwaterforreinforcedconcrete.Itmaybeusedfornon-reinforcedconcreteonlywhenitisdifficulttoobtaincleanfreshwater. Onemustnotethat,whenseawaterisused,thesettingtimeofthecementbecomesshort,sotheconcretetendstoloseitsconsistencyatanearlystage.Insuchcasesaretardermaybeusedasnecessary.

3.2 Concrete Quality and Performance Characteristics

(1)Concreteshouldbeofuniformqualitywithgoodworkabilityandhavethepropertiesformeetingthestrengthrequirements,durability,impermeability,crackresistanceandprotectionofsteelreinforcement.

(2)Concreteshouldberesistantagainstdeteriorationcausedbyenvironmentalactions,wavesandmechanicalactionssuchasimpactandfrictioncausedbydriftingsolids.

(3)CharacteristicValuesforConcreteStrength

① For the characteristic values of concrete strength of an ordinary concrete to be used in the performanceverificationofthemainstructuralmembersofportfacilities,itisusuallypossibletousethevaluesgiveninTable 3.2.1asstandardvalues.

Table 3.2.1 Standard Characteristic Values of Concrete Strength of Ordinary Concrete

Concretetype CharacteristicvalueofconcretestrengthNon-reinforcedconcrete Compressive 18(N/mm2)Reinforcedconcrete Compressive 24(N/mm2)Concreteforapronpavement Bending 4.5(N/mm2)


–339–

Forreinforcedconcrete,incaseswhenthemaximumwater-to-cementratioisspecifiedas50%orlowerinconsiderationofdurability,30N/mm2maybeusedas thecharacteristicvaluefor thecompressionstrength.Forconcretelidsofnon-reinforcedconcrete,incaseswherethereisariskofwaveimpactorsubmergingintheearlystageafterconcreteplacement,orwhenconstructionisdoneinacoldclimate,acharacteristicvalueof24N/mm2maybeusedforthecompressionstrength.Forlarge,deformedblocksofnon-reinforcedconcreteitispossibletospecifythecharacteristicvaluebasedontheconditions,suchasusing21N/mm2asthecharacteristicvalueforcompressionstrengthfortypesfrom35tto50toftheirnominalweights.

② Characteristic values for the bond strength of ordinary concrete in the performance verification can becalculatedfromequation (3.2.1).2)

(3.2.1)

where fbok

= characteristicvalueofthebondstrengthofordinaryconcrete(N/mm2) fck

= characteristicvalueofthecompressivestrengthofordinaryconcrete(N/mm2)

Equation (3.2.1)appliestotheuseofdeformedreinforcingbarconformedtoJIS G 3112, Steel Bar for Reinforced Concrete.Whenordinaryroundsteelbarsareused,valuesthatare40%ofthevaluescalculatedfromequation (3.2.1)maybeusedundertheconditionofprovidingsemicircularhooksontheedgesofthereinforcement.

(4)Mixtureconditionsforconcretemustbespecifiedappropriatelyinconsiderationofdurability.Table 3.2.2,whichprovidesstandardmixtureconditionsforeachtypeofstructuralmember, isbaseduponverificationresultsoftheexistingconcretestructuresinportsanduponresearchresultsandtechnicalknowledgeonthedurabilityofconcretethatisaffectedbyseawater,andmaybeusedasareference.Forthestructuralmembersforwhichtherehavebeenlossinperformancebychlorideattack,suchasthesuperstructuresofpiers,itisnecessarytoexaminedurability,changesinperformanceovertime,andappropriatelyspecifythemixtureconditionsinordertoachievethedesiredperformanceforthefacility.SuchexaminationsmayrefertoPart III, Chapter 2, 1.1.5, Examination on Change in Performance Over Time,andPart III, Chapter 5, 5.2, Open-type Wharf on Vertical Piles.

Table 3.2.2 Reference for Concrete Mixture Conditions based on the Type of Structural Member

Type Examplesoftypesofstructuralmembers

MixtureconditionsMaximumwater-to-cementratio(%)

Maximumsizeofcoarseaggregate

Regionswherefreezingandthawingrepeatedlyoccurs

Regionswherethetemperaturerarelygoesbelowthe

freezingpointofwater

Non-reinforcedconcrete

Superstructure of breakwater, concrete lid,mainblock, deformed block (for wave dissipation orshielding),footprotectionblock,packedconcrete

6565 40

Superstructure of quaywall, parapet, mooringverticalfoundation(gravitytype) 60

Reinforcedconcrete

Mooringpostfoundations(pile-type),chestwalls,superstructureofquaywalls*1) 60 65 20,25,40

Superstructureofopen-typewharf – – –Caisson,well,cellularblock,L-shapedblock 50 50 20,25,40Wave-dissipatingblock 55 55 20,2540Anchorwall,superstructureofanchorpiles 60 60 20,25,40

Concreteforapronpavement – – 25(20)*2),40*1) Excludessuperstructureofpiers.*2) Use25mmforgraveland20mmforcrushedstone.

(5)Concretemusthavethebestconsistencysufficientforitsworkingconditions.Asarule,AEconcreteshallbeusedwhentherearenospecialrequirements,usuallywithanaircontentof4.5%.Incoldareaswherethereisariskoffrostdamagetheaircontentmustbeappropriatelyspecified.

(6)Recently, a high performance concrete with self-compacting characteristics has been developed.3), 4) Itscharacteristicshavebeenmaterializedthroughitshighfluidityandoutstandingresistancetomaterialsegregationbythecombineduseofappropriateadmixtures.Theuseofthishigh-performanceconcretemakesitpossibletoplaceconcreteintosectionssuchasincongestedreinforcedsectionsorinspacesenclosedbysteelshellsinwhich

–340–


concreteplacinghavebeendifficultbyusingordinaryconcrete.

(7) ConstructionJointsIncaseofportfacilities,damageoftenarisesfromjointsintheconcrete.5)Therefore,constructionjointsshouldbeavoidedasmuchaspossible.Whenjointsareinevitableinviewofshrinkageoftheconcreteortheconditionsofconstruction,necessarymeasuresshouldbetakenonthejoints.6)

(8) SurfaceProtectionForfacilitiesthatexperienceharshconditionssuchasabrasionorimpact,suchasfromflowingwaterthatcontainssandparticlesorfromwavesthatcontainpebbles,itisnecessarytoprotectthesurfaceswithappropriatematerials,ortoincreasethematerial’scross-sectionortheconcretecovertoreinforcement.Surfaceprotectionmaterialsincludesurfacecoatingsthatusetimber,highqualitystone,steelmaterials,orpolymermaterials,andalsoincludepolymer-impregnatedconcrete.

(9) StructuralTypesItisknownthatthereisacloseconnectionbetweenthestructuraltypeofafacilityandtheoccurrenceofchloride-induceddeterioration.Asfarasthetypeofmemberisconcerned,beamsandslabsaremoresensitivetochloride-induceddeteriorationthanarecolumnsandwalls.Chlorideions,oxygen,andwatercausedeteriorationwhentheypenetratethroughtheconcretesurface,soitispreferabletomaketheareaoftheconcretesurfaceofamemberassmallaspossible.Forexample,itiseasiertodecreasetheconcretesurfaceareabyusingbox-shapedbeamsandslabsthanbyusingT-shapedbeamsandI-shapedbeams,andthisisdesiredfromtheviewpointofdurability.Assumingthattherewillbedegradation,anadditionalconsiderationistoselectstructuraltypesthatpermiteasyrepair,strengthening,orreplacement.

3.3 Underwater Concrete

(1)Performance verification of underwater concrete shall be verified its performance andbe executed accordingtoStandard Specifications for Concrete Structures 7) orPort and Harbor Construction Work Common Specifications.8)

(2)Inadditiontotheunderwaterconcretethathasgenerallybeenusedinthepast,todayitisalsopossibletouseanti-segregationunderwaterconcrete,whichusesanti-segregationunderwateradmixtureswhosemaincomponentsarecelluloseoracrylicwater-solublepolymers.

(3)Itispreferabletoavoidconcreteconstructionjoints,andwhentheyarenotavoidableappropriateprocessingmustbeperformed.

(4)Theconcretecoverusedinunderwaterconstructionshouldbe10cmormore.Thisvalueisdeterminedbyreferringto sources such as standards for underwater concrete used for cast-in-place pile and continuous undergroundwalls.

3.4 Concrete Pile Materials

(1)Thephysicalvaluesofconcretepilematerialsusedinportfacilitiesshallbeappropriatelyspecifiedbasedontheircharacteristics.

(2)PrecastConcretePileMoldedbyCentrifugalForcePrecastconcretepilemoldedbycentrifugalforceincludesRCpile,whichisareinforcedconcretepilethatismadeinthefactory,PCpile,towhichatensileforceisappliedtoreinforcementorPCtendon,therebyincreasingitstensilestrengthandbendingstrength(andthisisdividedintothreetypes,A,B,andC,basedontheamountofeffectivepre-stress),andPHCpile,whichuseshigh-strengthconcretewithastandarddesignstrengthof80N/mm2ormore.Recently,themaintrendhasbeentousePHCpile.Besidethese,therearePRCpiles,whichisapilethataddsreinforcementtoPHCpileinordertoincreaseitstoughness,andSCpile,whichhashigh-strengthconcreteinsideofasteelpipetoprovidelargebendingstrengthandshearstrength.ForthesetypesofprecastconcretepiletheJapaneseIndustrialStandardhasJIS A 5372, Prestressed Reinforced Concrete Products,forRCpileandSCpile,andJIS A 5373, Precast Prestressed Concrete Products,forPHCpileandPRCpile. In theperformanceverification,when specifyingcharacteristicvalues for theconcrete strengthandyieldstrengthofsteelofprecastconcretepileitispossibletorefertoJIS A 5372andJIS A 5373,whileforPCsteelbarsonecanrefertoJIS G 3137, Small Diameter Deformed PC Steel Bars,forthereinforcementofPRCpileonecanreferenceJIS G 3112, Steel Bars for Reinforced Concrete,andforthesteelpipesofSCpileonecanreferenceJIS A 5525, Steel Pipe Pile.

(3)Cast-In-PlaceConcretePileCast-in-placeconcretepileisdividedintotypeswithandwithoutanoutershell.Thespecialfeatureofcast-in-placeconcretepileisthatthepileisconstructedwhileitissituatedintheground.Therefore,thecast-in-place


–341–

concretepileisdifferentfromtheprecastconcretepileinthatitisnotnecessarytobeconcernedwithinfluencessuchasimpactwhenitisplacedintotheground,butrather,differentfromthecasewhenitisfabricatedonland,thereistheproblemthatduringitsconstructionitisinfluencedbypileconstructedinthesurroundingground.Forthisreason,thecast-in-placeconcretepilehassomeinsecurecharacteristicsduringconstruction,andthosewithoutanoutershellhavegreater insecurity,socaremustbetaken. Areferenceforcast-in-placepile is theSpecification for Highway Bridges, Part 4, Substructures.13)

References

1) Fukute,T.,K.YamamotoandH.Hamada:Astudyofthedurabilityofoffshoreconcretemixedwithseawater,ReportofPHRI,Vol.29,No.3,1990

2) JSCE:StandardSpecificationsforConcreteStructures,Structuralperformanceverification,20023) FukuteT.,H.Hamada,K.Miura,K.Sano,A.MoriwakeandK.Hamazaki:Applicabilityofsuper-workableconcreteusing

viscousagenttodenselyreinforcedconcretemembers,Rept.ofPHRIVol.33No.2,pp.231-257,19944) CoastalDevelopmentInstituteofTechnology(CDIT):High-fluidityConcreteManualforPortFacilities,19975) Seki,H.,Y.OnoderaandH.Maruyama:DeteriorationofPlainConcreteforCoastalStructuresUnderMaritimeEnvironments,

TechnicalNoteofPHRI,No.142,19726) Otsuki,N.,M.HarashigeandH.Hamada:TestontheEffectsofJointsontheDurabilityofConcreteinMarineEnvironment

(after10years’exposure),TechnicalNoteofPHRI,No.606,19887) JSCE:StandardSpecificationsforConcreteStructures,Construction,20028) JapanPortAssociation:StandardSpecificationsforPortConstructionWork,JapanPortAssociation,20059) CoastalDevelopmentInstituteofTechnology(CDIT)andJapaneseInstituteofTechnologyonFishingPorts,Groundsand

Communities:Manualfornon-disjunctionunderwaterconcrete,(Designandconstruction),198910) JSCE:Guidelinefordesignandconstructionofunti-segregationconcrete inunderwater (Draft),JSCEConcreteLibrary,

No.67,199111) CoastalDevelopmentInstituteofTechnology(CDIT):Manualforsealingconcreteconstructionwithvibrator(forimmersed

tunnelelementofsteelandconcretesandwichstructure),200412) CoastalDevelopmentInstituteofTechnology(CDIT):TechnicalManualforPCsheetpileforportconstructionwork,2000.13) JapanRoadAssociation:SpecificationsandcommentaryforHighwayBridgesVol.IV,Substructures,pp.418-424,2002

–342–


4 Bituminous Materials4.1 General

(1)Bituminousmaterialsusedinportfacilitiesshallsatisfytherequiredqualityandperformancerequiredtoachievetheperformancerequirementoffacilities.Theseshallincludeelasticity,cohesion,impermeability,waterproofness,durability,andweatherproofness.

(2)Bituminousmaterialsarerarelyusedalone.Asphalt,forexample,isusuallymixedwithaggregateandusedasanasphaltmixtureinasphaltconcreteforpavement,asphaltmats,sandmasticasphalt,andasphaltstabilization.Thetypeandmixproportionofasphaltdependonitsuse.Therefore,itisimportanttoselectamaterialthatwillmeettherequiredobjective.

4.2 Asphalt Mats4.2.1 General

(1)Asphaltmatsshallhaveanappropriatestructureinconsiderationoftherequiredstrength,durability,andworkabilitybasedonthepurposeoftheiruse,thelocationoftheiruse,andtheenvironmentalconditionsofthesite.

(2)Asphaltmats aremadeby embedding reinforcementmaterial andwire rope for suspension into a compoundmaterialmixedfromasphalt,limestonefiller,sandandcrushedstone.Theyarethenformedintoamat-shape(seeFig. 4.2.1).

Annealedsteel wire

Reinforcementcore material

Anti-slip bracket

Steel reinforcementWire ropeAsphalt compound material

Steelbands

Fig. 4.2.1 Example of Structure of Friction Enhancement Asphalt Mat

(3)Types of asphaltmats include friction enhancementmats that increase the sliding resistance of gravity typestructure walls, scouring prevention mats that prevent the scouring of structural foundations, and sandwashingoutpreventionmatsthatpreventthewashingoutoffoundationsandmoundandbackfillingsandfromrevetments.Whenasphaltmatsareusedsufficientcareshouldbegiventotheirquality,long-termdurability,andconstructability,basedonthepurposeoftheiruse,thelocationoftheiruse,andtheenvironmentalconditionsofthesite.Inparticular,whentherearespecialenvironmentalconditionssuchascoldregions,subtropicalregions,ortidalzones,onemustconsidertheharshenvironmentalconditionswithregardtolong-termdurability,1),2)andcarefulstudiesshouldbemade,includingthedeterminationofappropriateness.

4.2.2 Materials

(1)Asphaltmatmaterialsshallbeselectedasappropriatetoyieldtherequiredstrengthanddurability.

(2)Thefollowingmaterialscanbeusedinasphaltmats:

① Asphalt

② Sand

③ Filler

④ CrushedStone


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4.2.3 Mix Proportion

(1)Themixproportionusedforasphaltmixture isdeterminedbymixproportion test toget thedesiredstrengthandflexibility. Frictionenhancementmatsandscouringpreventionmatshavea relatively longhistoryandaconsiderablylongrecordofuse.Theyhavecausednoparticularproblemtodate.3)Therefore,thevaluesgiveninTable 4.2.1 maybeused,exceptforspecialuseconditions.

Table 4.2.1 Standard Proportion for Asphalt Mixture

MaterialRatiobymass(%)

Frictionenhancementmat ScouringpreventionmatAsphalt 10–14 10–14Dust 14–25 14–25

Fineaggregate 20–50 30–50Coarseaggregate 30–50 25–40

Notes:Dustissandorfillerwithagrainsizeof0.074mmorless.Fineaggregateiscrushedstone,sand,orfillerwithagrainsizefrom0.074to2.5mm.Coarseaggregateiscrushedstonewithagrainsizeof2.5mmorlarger.

4.3 Paving Materials

(1)Pavingmaterials shall inprinciple complywithAsphalt Paving Guidelines,5) except in the areas subject tospecialloadconditions.

(2)Apronsareanexampleofthe“areassubjecttospecialloadconditions”.Trafficonpavementsparticularlyapronpavinginportareas,unlikethatonroadsincityareas,almostinvariablyinvolvesheavyvehicles.Thisincludesheavymachinerywithlargecontactpressure.Thistypeofloadrarelytravelsathighspeedandisalmostalwaysstationaryormovingat lowspeeds. Partsof thesepavedareasarealsousedforcargostacking. Thus,whenconsidering thepavingmaterials tobeapplied tosuchareas,careshouldbe taken to thefact thatbituminousmaterialsaresusceptibletostaticloading.Part III, Chapter 5, 9.14. Aprons canbeusedasareference.

(3)Gussasphaltpavinghasthepropertiesofbeingnon-permeableandoffollowingdeflectionwell,soitisoftenusedforsteelfloorslabpavingandbridgesurfacepaving.

4.4 Sand Mastic4.4.1 General

(1)Sandmasticasphaltismadeofasphaltheat-mixedwithanore-basedfilleroradditiveandsand.Thesandmasticasphaltisanasphaltmixturevirtuallyfreeofvoidsanddoesnotrequirerollingcompactionaftergrouting.

(2)Sandmasticasphaltatacertainhightemperatureisgroutedintogapsbetweenrubbleswithoutsegregationinwaterbypouringitontotherubblemound.Thegroutedsandmasticasphaltwrapsitselfaroundtherubbletoformasingleunit,thuspreventingthestonefrombreakingofforbeingwashedaway.Itissometimesusedwhenitisnotpossibleoruneconomicaltoobtainrubblesofthesizerequired.

(3)Whenconductingtheperformanceverificationofsandmasticasphalt,dueattentionshouldbepaidtotheplasticflowduetothematerialpropertiesofasphaltsothatstabilityproblemwillnotarise.

4.4.2 Materials

(1)Materialsforsandmasticasphaltshallbeselectedasappropriatetomeettherequiredstrengthanddurability.

(2)Forexample,thefollowingcanbeusedassandmasticmaterials:

① Asphalt

② Sand

③ Filler

(3)Asphaltthatisusedassandmasticinunderwaterconstruction6),7)shouldhavesufficientfluiditysothat,ifitisfloweddown,therubbleiscompletelyfilledinwithnopores.

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(4)Withregardtotheeffectofsandonmixtures,thelargerthesandgrainsthegreateristhefluidityofthemixture,andalthoughacertainamountoffluiditycanbeobtainedwithasmallamountofasphalt themixturereadilysegregates. Thesmaller thegrainsizethelessfluiditythereis,creatingadensesandmastic. Therefore, it ispreferable that the sand grain sizes be continuous,where the grain-size curve changes smoothly, so that themixturedoesnotsegregate.

(5)Whenfillerismixedintoasphaltmixtures,itmixeswiththeasphalttofillinthespacesamongtheaggregatewhilesimultaneouslyworkingasabindingagenttodecreasethefluidityofthemixture,thusincreasingtheviscosityandstability.Asphaltusuallyadhereswelltofillerthatisslightlyalkali,soitispossibletousefillermadefromslightlyalkalilimepowder.

4.4.3 Mix Proportion

(1)Themixproportionshallbedeterminedthroughmixingteststoobtaintherequiredfluidityandstrengthinviewoftheworkandnaturalconditions.

(2)GeneralThe values listed inTable 4.4.1 are commonly used as the mix proportion for sand mastic asphalt appliedunderwater.

Table 4.4.1 Standard Proportion for Sand Mastic Asphalt Mix

Material Proportionbymass(%)AsphaltDust

Fineaggregate

16–2018–2555–66

Note:Dustreferstosandorfillerpassedthrougha0.074mmsieve.Fineaggregateiscrushedstone,sand,orfillerremainingona0.074mmsieve.

(3)NotesonthePerformanceVerificationNotesonthedesignofsandmasticasphaltisasfollows:

① Itshouldnotbeusedinlocationsdirectlyaffectedbypowerfulimpulsivewavepressureordriftingobjects.

② Itshouldnotbeusedinlocationswhererapidsedimentationisanticipated.

③ Thegradientoftherubblesurfacewheresandmasticisexecutedispreferablygentlethan1:1.3.

④ Suitablereinforcementshouldbeusedontheslopeshoulder,slopetoe,andtheedgesoftheexecutionarea.

⑤ Therelationshipbetweenthedesignworkinglifeofportfacilitiesandthedurabilityofthesandmasticasphaltshouldbefullytakenintoaccount.

References

1) Imoto,T.,Y.Mizuno andK.Yano:Research on durability of asphaltmats employed in the gravity type port facilities,ProceedingsofOffshoreDevelopment,JSCE,toutilizedtoSurveyVo1.5,pp.119-124,1989

2) MizunoY.,M.Tokunaga,Y. Sugimoto,K.Murase andO.Yasuda:Development and study of asphaltmats for frictionincreaseofgravitytypeofoffshorestructuresincoldseaarea,ProceedingsofOffsshoreDevelopmentVol.8,pp.171-176,1992

3) Kataoka, S.,K.Nishi,M.Yazima andO.Miura:Durability of asphaltmats placed underCaisson for friction increase,Proceedingsof30thConferenceonCoastalEng,pp,643-647,1983

4) Itakura,T.andT.Sugahara:RecentDevelopmentofAsphaltutilization,JournalofJapanesePetroleumInstituteVol.7,No.8,p.9,1964

5) JapanRoadAssociation:Essentialpointsofasphaltpavement,19986) Studygroupforasphaltmixtureforhydraulicstructures:Asphaltmixtureforhydraulicstructures-materials,designand

constructionforfieldengineers-,KajimaPublishing,19767) Kagawa,M.andT.Kubo:Experimentalstudyonstabilityofrublespouredsandmastic,Proceedingsof12thConferenceon

CoastalEng,.JSCE,1965


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5 Stone5.1 General

(1)Stoneshallbeselectedinviewoftherequiredqualityandperformancetosuititspurposeanditscost.

(2)Generally,stoneisusedinlargequantitiesforportfacilitiessuchasbreakwatersandquaywalls. Selectionofstonematerialshasamajorimpactonthestabilityofthestructureaswellastheperiodandcostofconstruction.

(3)ThetypesofstonemainlyusedinportconstructionandtheirphysicalpropertiesaregiveninTable 5.1.1. Itshouldbeborneinmindthatthephysicalpropertiesofstoneofthesameclassificationmaydifferdependingontheregionandsiteofquarries.

Table 5.1.1 Physical Properties of Stones

Rockclassification Subclassification Apparentdensity(t/m3)

Waterabsorptionratio(%)

Compressivestrength(N/mm2)

Igneousrock

GraniteAndesiteBasaltGabbroPeridotiteDiabase

2.60–2.782.57–2.76

2.68(absolute)2.91(absolute)

3.182.78–2.85

0.07–0.640.27–1.12

1.850.210.16

0.008–0.03

85–19078–269

85177187

123–182

Sedimentaryrock

TuffSlate

SandstoneLimestoneChert

2.642.65–2.742.29–2.722.36–2.71

2.64

0.160.08–1.370.04–3.650.18–2.59

0.14

37759–18548–19617–76119

Metamorphicrock Hornfels 2.68 0.22 191

5.2 Rubble for Foundation Mound

(1)Rubbleforfoundationmoundsshallbehard,denseanddurable,andfreefromthepossibilityofbreakingduetoweatheringandfreezing.Theshapeofrubblesshallnotbeflatoroblong.

(2)Whendeterminingwhichtypeofstonetouse,testsshouldfirstbeconductedandthematerialpropertiesbefullyascertained.Theeaseofprocurement,transportability,andpriceshouldalsobetakenintoaccount.

(3)TheshearpropertiesofrubblestoneshavebeenstudiedbyShoji1)usingvariouslarge-scaletriaxialcompressiontests.Thisstudyisbasedonthestateofrubbleactuallyusedinportandharborconstructionworks.

(4)AsaguidelineproposedbyMizukamiandKobayashi2)fordeterminingthestrengthconstantwithoutconductinglarge-scaletriaxialcompressiontests,ashearstrengthof0.02N/mm2andashearingresistanceangleof35ºcanbeexpectediftheunconfinedcompressivestrengthis30N/mm2ormore.

5.3 Backfilling Materials

(1)Backfillingmaterialsshallbeselectedinviewoftheirpropertiessuchasangleofshearresistanceandspecificweight.

(2)Rubble,unscreenedgravel,cobblestone,andsteelslagaregenerallyusedasbackfillingmaterials.Thematerialpropertiesofmudstone,sandstone,andsteelslagvarygreatly,andthereforetheseshouldbeexaminedcarefullybeforeuse.

(3)ThevalueslistedinTable 5.3.1 areoftenusedascharacteristicvaluesforbackfillingmaterials.

(4)“Rubble”usedinportsandharborshastheequivalentperformanceto“riprap”prescribedbyJISA5006.

(5)“Unscreenedgravel”consistsapproximatelyhalfandhalfofsandandgravel.

(6)Theslopegradientisthestandardvalueofthenaturalgradientofbackfillingmaterialsexecutedinthesea.Generally,alargervalueisadoptedwhentheeffectofwavesaresmallatthetimeofbackfillingexecution,andasmallervaluewhentheeffectofwavesarelarge.

(7)Forsteelslag,see7.2 Slag.

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Table 5.3.1 Characteristic Values for Backfilling Materials

Angleofshearresistance(°)

Unitweight

SlopegradientAboveresidualwaterlevel

(kN/m3)

Belowresidualwaterlevel

(kN/m3)

Rubble OrdinarytypeBrittletype

4035

1816

109

1:1.21:1.2

Unscreenedgravel 30 18 10 1:2−1:3

Cobblestone 35 18 10 1:2−1:3

5.4 Base Course Materials of Pavement

(1)Basecoursematerialsofpavementshallbeselectedsoastohavetherequiredbearingcapacityandhighdurabilityandtoalloweasycompaction.

(2)Normally,granularmaterial,cementstabilizedsoil,orbituminousstabilizedsoilisusedasabasecoursematerial.Granularmaterials includecrushed stone, steel slag,unscreenedgravel,pitgravel,unscreenedcrushed stone,crushedstonedust,andsand.Thesemaybeusedontheirownormixedwithothergranularmaterials.

(3)Thebasecourseserves todisperse thesurcharge transmitted fromaboveand to transfer it to thecoursebed.Normally,itisdividedintoalowerbasecourseandanupperbasecourse.Materialsusedforthelowerbasecoursearecheaperandhaverelativelysmallbearingcapacity.Theupperbasecourserequiresmaterialsofgoodqualitywithlargebearingcapacity.

References

1) Shoji, Y:. Study on shearing Properties of Rubbleswith Large Scale Triaxial Compression Test, Rept. of PHRIVol.22No.4,1983

2) Mizukami,J.andM.KobayashiSoilStrengthCharacteristicsofRubblebyLargeScaleTriaxialCompressionTest,TechnicalNoteofPHRINo.699,p.20,1991

3) JapanRoadAssociation:Cementconcretepavement,MaruzenPublishing,19974) JapanRoadAssociation:Essentialpointsofasphaltpavement,1998


–347–

6 Timber6.1 GeneralTimberhasthefollowingcharacteristicsincontrasttootherconstructionmaterials.Itisnecessarytoconsiderthesecharacteristicswhenusingtimberinportfacilities.

(1)StrengthPerformanceTimber’s strength per unitmass is high. Strength along fiber direction is greater than that perpendicular tothefiber. Strength in tension is greater than in compression, and bending failure begins by buckling on thecompressedside.Theshearstrengthissmall.Thechangesinstrength,dimensions,andspecificgravityduetowatercontentcannotbeignored.Thereislargecreepdeformationunderacontinuousload.

(2)DurabilityDegradation,suchasdiscoloration,surfacecontamination,morphologychange,andreductioninstrengthmayoccurduetoorganismssuchasfungi,insects,andmarineborersandmeteorologicalfactorssuchasultravioletlight,rain,andtemperature.Themaindegradationfactorsvarygreatlydependingontheusageenvironmentandthewatercontent.

(3)EnvironmentalCharacterWoodgrowsbyusingsolarenergytofixcarbondioxidefromtheair,soitisamaterialthatresultsinlittlecarbondioxidereleaseasaresultofitsgrowth.Theuseofwoodfromroutinethinningcontributestotheconservationofartificialforests.Oneshouldbecautiousaboutusingtimberfromnaturalforestsforreasonssuchasthatitleadstothedestructionofforests.

(4)OtherTimberiscombustible.Itisattractiveifthereistheproperamountofirregulargrainpatternsandcolorvariation.Thesmellispleasingtomindandbody.Ithasmoderatesoftnesstopreventinjurieswhenonefallstoit.Itiswarmtothetouchbecauseithaslowheatconductance.Itsfrictionalcoefficientsarelarge,withalmostnodifferencebetweenthestaticfrictioncoefficientanddynamicfrictioncoefficient,soitiseasytowalkon.

6.2 Strength PerformanceThespecificationofcharacteristicvaluesfortimberstrengthandtheverificationofitsstrengthasamaterialcanbebasedontheRecommendation forLimit State Design of Timber Structures (Draft) 1) oftheArchitecturalInstituteofJapan(hereafter,theRecommendation (Draft)).Thefollowingitemsareofparticularconcernwhentimberisusedinportfacilities.

(1)WaterContentThewatercontentofwoodisexpressedas(weightofwater)/(ovendryweightofthewood)x100(%).Waterwithinwoodiseitherboundwaterorfreewater.Boundwaterisboundtocellulosewithinthecellwallsofthewood.Freewaterexistsincellcavities.Ifthewatercontentisnomorethanabout28%thenthereisnofreewater. Boundwateraffectstimberstrength,butfreewaterdoesn’t. AsshownintheconceptualdrawingofFig. 6.2.1,thestrengthgoesdownastheboundwatercontentincreasesfromtheovendryconditiontoawatercontentof 28%, thefiber saturation point, and the strength stays roughly the samewhen thewater content increasesbeyond thefiber saturationpoint and the freewater increases. Under themeteorological conditionsof Japanthewater content reaches equilibrium around 15%. Therefore, the standard strength characteristic values intheRecommendation (Draft)arespecifiedbasedontestswithawatercontentof15%.TheRecommendation (Draft)definesconstantlywetconditionstobeusageenvironmentI,intermittentlywetconditionstobeusageenvironmentII,andotherenvironmentstobeusageenvironmentIII,andinusageenvironmentIthestandardstrengthcharacteristicvaluesarereducedbymultiplicationbyacoefficientof0.7,whileforusageenvironmentIItheyarereducedbyafactorof0.8.Forportfacilitiesallmaterialscanbeassumedtobeinawetcondition,soitisnecessarytoreducethestandardstrengthcharacteristicvaluesbythecoefficientforusageenvironmentIorII.

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0

1

2815Coe

ffic

ient

app

lied

to th

e st

reng

th

Water content (%)

Fig. 6.2.1 Effect of Water Content on Wood Strength (Conceptual Drawing)

Withregardtodimensionalchangesofwood,expansion,orshirinkage,itistrueagainthatboundwaterhasaneffectbutfreewaterdoesn’t.Thedimensionsgrowasthewatercontentincreasesfromtheovendryconditiontoawatercontentof28%,fibersaturationpoint,andthedimensionsstayroughlythesameasthewatercontentincreasesbeyondthefibersaturationpointand thefreewater increases. Thedimensionalchangeratiovarieswiththedirection,where“directiontangentialtotherings”>“directionradialwithrespecttotherings”»“fiberdirection”,witharatioofabout1:0.5:0.1.Thetotalexpansionratiofromthecompletelydryconditiontothefibersaturationpointcanreachabout6%forthedirectiontangentialtotheringsinJapanesecedar.Inapplicationswherethewatercontentbelowthefibersaturationpointisexpectedtochangeitisnecessaryforthedesigntoconsiderdimensionalchangesfromthebeginning. Thespecificgravityofwoodvariesgreatlywiththespeciesandwatercontent.Intheair-driedcondition,watercontent15%,thespecificgravityisabout0.38forJapanesecedarandabout0.53forlarch.Forundriedlogsimmediatelyafterfellingandtimberthatisusedunderwaterthewatercontentmayrangefrom80%to150%,sotheapparentspecificgravityincludingthewaterwouldbeasmuchastwicethatinairdry.Inthedesignofportfacilitiesitiscustomarytoassumethatthespecificgravityoftimberis0.8,usingadensityof7.8kN/m3,butitisnecessarytorememberthattheapparentspecificgravitycanvarygreatlywithspeciesandwatercontent,andnottoassumeaspecificgravityonthedangerousside.

(2)ContinuousLoadingTimeIntheRecommendation (Draft),therelationshipbetweencontinuousloadingtimeanditseffectontheinfluencecoefficientsisgivenasinFig. 6.2.2.Whenaloadcontinueslongerthan10minutes,whichisthestandardloadingtesttimeforwood,thestandardstrengthcharacteristicvalueistobemultipliedbyaninfluencecoefficientfortheeffectofthecontinuousloadingtime.Thus,forportfacilities,itisnecessarytospecifycontinuousloadingtimesforsuchfactorsasthetemporaryloadingtimeduringconstructionandthelong-termcontinuousloadingtimeaftercompletion,andreducethestrengthcharacteristicvaluesbytheinfluencecoefficientsforthoseeffects.

0.5

0.6

0.7

0.8

0.9

1

1.1

0.00001 0.001 0.1 10 1000

10 min :1.00

1 day :0.83

3 days :0.80

3 months :0.71

50 yrs : 0.55 250 yrs : 0.50

Influ

ence

coe

ffic

ient

Continuous loading time (Years)

Fig. 6.2.2 Continuous Loading Time and Influence Coefficients 1)


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(3)StandardStrengthCharacteristicValuesforLogs Inlogs,thefibersarenotcut,sologsaremechanicallybetterthanmanufacturedwood,andtheyaresuitableforportfacilitiesbothintermsofeconomicsandenvironmentalimpact.TheRecommendation (Draft)saysthatthestandardstrengthcharacteristicvaluesoflogsmaybetakenfromthestandardstrengthcharacteristicvaluesgivenformechanicalgradeclassificationsofmanufacturedwood.

6.3 DurabilityExamplesofdegradationphenomenathatoccurwhentimberisusedincludediscoloration,surfacecontamination,morphologychange,andreduction instrength. Whether theseareconsideredasproblemsdependson the timberapplication. Discoloration, surface contamination, and morphology change are problems in applications whereappearanceisimportant,suchasboardwalksanddecks.Whileforconstructionmaterialsthatareoutofsight,suchaspile,reductioninstrengthwouldbeaproblem.

(1)CausesofDegradation2)Examples of factors that causedegradationphenomena includeorganisms such as fungi, insects, andmarineborers3),4),5),andmeteorologicalfactorssuchasultravioletlight,rain,andtemperature.Themaindegradationfactorsdependontheenvironmentinwhichthetimberisusedanditswatercontent,asshowninTable 6.3.1.Thewatercontentconditionsinthetableare:“dry”,meaningtheconditionwherethewatercontentisbelowthefibersaturationpoint,about28%sothatthereisnofreewater,“wet”,meaningthatthewatercontentisatthefibersaturationpointorhigherbutthecellcavitiesarenotsaturatedwithwater,and“saturated”,meaningtheconditionwherethecellcavitiesaresaturatedwithwater.

Table 6.3.1 Usage Environments and Degradation Factors

Usageenvironment Examplesofapplication

Watercontentcondition Maindegradationfactors

Indoor ResidenceDry BoringbeetlesWet Fungi,termites

Outdoor

Intheair Outdoorconstruction

Dry Meteorologicalfactors,boringbeetles

Wet Fungi,termites,meteorologicalfactors

Intheground PileWet Fungi,termites

Saturated None

Infreshwater Riverfacilities

Wet FungiSaturated None

Intheseawater Portfacilities

Wet Fungi,marineborerSaturated Marineborer

(2)PreventativeMeasuresforDegradationExamples of preventativemeasures for degradation include the use of naturalmaterialswith high durability,protectiveprocessing,andmaintenance.6)

References

1) ArchitecturalInstituteofJapan:RecommendationforLimitStateDesignofTimberStructures(Draft),20032) JapanWoodPreservingAssociation:Introductionforthepreservationofwood‘RevisedEdition'),20013) Okada,K.Edition:Shipwormdamageofwoodenvesselanditscountermeasures,JapanSocietyforthePromotionofscience,

19584) Tsunoda,K.andNishimoto,K.:Shipwormattackintheseawaterlogstorageareaanditsprevention(3),Settlementseason

ofshipworm,WoodIndustryVol.35,pp.166-168,19805) Yamada,M.:DurabilityTestofUntreatedWoodandWood-powder/plasticCompositeinMarineEnvironment,Technical

NoteofPARINo.1045,20036) JapanWoodPreservationAssociation:MaintenanceManualofwoodenexteriorstructuralmaterials,2004

–350–


7 Recyclable Materials7.1 General

(1)Recyclablematerialsshallbeusedasappropriateinaccordancewiththecharacteristicsofthematerialsandthefacilities.

(2)Recyclablematerials in port construction include slag, coal ash, crushed concrete, dredged soil, and asphaltconcretemass. Most of these canbeused in landfillmaterials, sub-base coursematerials, soil improvementmaterials,andconcreteaggregate.

(3)Effective use of recyclable materials is extremely important. Port and harbor construction works use largequantitiesofmaterialsanditis,therefore,veryimportantthattheycontributetoenvironmentalconservationandsustainabledevelopmentbyrecyclingandusingfewernaturalmaterials.Wealsoneedtoundertakeexhaustivestudiesbeforeusingrecycledmaterialstoensurethatnoenvironmentalissuesarise.

(4)Thepropertiesofrecyclablematerialsarequitevariable.Therefore,theirphysicalanddynamicpropertiesandthevolumetobesuppliedshouldbefullyexaminedinadvancetoensurethepurposeofuse.

7.2 Slag

(1)Slagincludesferro-slag,watergranulatedcopper-slag,andferronickelgranulatedslag

(2)Ferro-slag2)isindustrialwastegeneratedinlargequantitiesbythesteelindustry.Itisbroadlydividedintoblastfurnaceslagandsteel-makingslag.

(3)Air-cooled blast furnace slag is a granularmaterialmainly used as road constructionmaterial and has beeneffectivelyutilized.Watergranulatedblastfurnaceslagisalightweightsand-likematerial.Aswellasbeingusedasarawmaterialforblastfurnacecement,itisalsoincreasinglyusedasabackfillingmaterialforportsfacilitiesandsandcompactionmaterial,inviewofitslightness.3),4),5)

(4)Becausesteel-slagcausesexpansionanddisintegrationwhenfreelimereactswithwater,inordertoavoidadverseeffect,itissteamautoclavedandusedasroadandsoilimprovementmaterials. Table 7.2.1 2) listsacomparisonofchemicalcompositionsofferro-slagandordinaryearthmaterials.Table 7.2.2 liststhephysicalanddynamicpropertiesofsteel-slagandair-cooledblast-furnaceslag. Water granulated copper-slag is a sandymaterial obtained through high-speed coolingwithwater in thecopperrefiningprocesssimilartothewatergranulatedblastfurnaceslag.Ithasahigherparticledensitythansand.Althoughitissusceptibletoparticlecrushing,itsangleofshearresistanceandhydraulicconductivityareaboutthesameasthoseofbeachsand.Aswellasbeingusedforfineaggregateofconcrete,sandmatandasafillingmaterial,ithasbeenexperimentallyusedinthesandcompactionpilemethod.6),7) Ferronickelgranulatedblastfurnaceslagisobtainedduringthemanufacturingofferronickelthatisarawmaterialforstainlesssteel.Itsspecificweighislargerthanthatofsand,andhasbeenusedasacaissonfillingmaterial.

Table 7.2.1 Chemical Compositions of Slag and Other Materials 2) (Units：%)

Item

Component

Blastfurnaceslag

Converterslag

ElectricfurnaceslagMountain

soil AndesiteOrdinaryPortlandcement

Oxidizingslag Reducingslag

SiO2 33.8 13.8 17.7 27.0 59.6 59.6 22.0CaO 42.0 44.3 26.2 51.0 0.4 5.8 64.2Al2O3 14.4 1.5 12.2 9.0 22.0 17.3 5.5T-Fe 0.3* 17.5 21.2 1.5 – 3.1* 3.0**MgO 6.7 6.4 5.3 7.0 0.8 2.8 1.5S 0.84 0.07 0.09 0.50 0.01 – 2.0***

MnO 0.3 5.3 7.9 1.0 0.1 0.2 –TiO2 1.0 1.5 0.7 0.7 – 0.8 –Note)*：FeO,、**：Fe2O2,***：SO3


–351–

Table 7.2.2 Physical and Dynamic Properties of Steel-Slag and Air-Cooled Blast Furnace Slag

Steel-slagAir-cooledblastfurnaceslag

MS–25 CS–40Bonedrynessdensity(BD)(g/cm3) 3.19–3.40 – –Waterabsorptionrate(%) 1.77–3.02 – –Unitweight(kN/m3) 19.7–22.9 17.2–17.8 16.7–17.2Optimummoisturecontent(%) 5.69–8.24 8.8–9.4 8.4–9.0Maximumdrydensity(g/cm3) 2.34–2.71 2.18–2.21 2.13–2.17ModifiedCBR(%) 78–135 170–204 152–186Coefficientofpermeability(cm/s) 10-2–10-3 10-2–10-3 –Angleofshearresistance(°) 40–50 – –

(5)Recently, hydration-hardened steel- slag is used as a civil engineeringmaterial for port facilities, such as fordeformed blocks, foot protection blocks, and dumping blocks. For details, one can refer to theHydration-Hardened Steel-Slag Technical Manual (Supplementary Edition).9)

7.3 Crushed Concrete

(1)Crushed concrete hasmainlybeenused as a base coursematerial for pavement so far, 15) but recently it hasbecomedifficulttoobtaingoodqualityaggregatesothereareattemptstoalsouseconcreteasanaggregate.

(2)Whenusingcrushedconcreteasamaterialforaggregate,thepropertiessuchastheangleofshearresistancevarydependingonmotherconcrete.Thus,underpresentcircumstancesitisdifficulttogivethestandardvaluesoftheirproperties.Ifthepropertiesoftheconcretebeforecrushingaresimilartothosepresentedinreference18),thepropertiesofcrushedconcretecanbedeterminedbyreferringtoit.

7.4 Dredged Soil

(1)Dredgedsoilhasbeenusedasa landfillmaterial,andwhenno landfillarea isunderconstructionat the timeofdredgingithasbeenusedtofillinlandatwastedisposalsitesinportareas.Inprojectsatportsandcoastalairports, large amounts of soils are always used for purposes such as backfilling of quaywalls and seawalls,constructionofreclamationland,andimprovementofsoftsubsoil,soifdredgedsoilcouldbeusedforalargerpercentageofsuchmaterialsthenthatwouldbeextremelyeffectiveinprolongingthelifeofwastedisposalareasandreducingconstructioncosts.

(2)Whensandydredgedsoilisusedasreclamationorbackfillitmaybestaticallystablebutagroundformsthatliquefiesextremelyeasilyduringgroundmotions,sosomepreventativemeasuresarerequiredagainstliquefaction.Also,cohesivedredgedsoilbecomesaverysoftgroundwithahighwatercontent,sosoilimprovementisrequiredafterreclamation.Inthepast,onesoilimprovementmethodthathasoftenbeenusedistheinstallationofverticaldrainstopromoteconsolidationafterthesurfacelayerhardens.Inrecentyearsmethodsofsoilimprovementhavebeendevelopedwheredredgedcohesivesoilisfirsthardenedandthenusedforreclamationorbackfill.Theseincludethemethodthatusespecialhardeningtreatmentshiptomixthesoilhardeningagentsandthenuseitasreclamation,themethodthatmixthesoilwithhardeningagentswhileitisbeingtransportedbybargesandthenuseitasreclamation,andthemethodthatmixitwithhardeningagentson-site.

(3)Pneumaticflowmixingmethodsarehardeningmethodsthathavebeennewlydevelopedinordertousedredgedsoilmoreeconomicallyasareclamationmaterial.Suchmethodaddhardeningagentswhilesoilisbeingtransportedbyairpressurewithinatube,anduseuniquemixingequipmenttoenhancethekneadingeffectofthedredgedsoil’splugcurrentgeneratedunderthepressurizedflow,soastosimultaneouslytransportandhardenthedredgedsoil.Proposedmethodsofmixingwithhardeningagentsincludethemethodthatpassthesoilthroughlinemixers,themethodthataddandmixinpowderedhardeningagents,themethodthatfirstaddinhardeningagentsandthenpassthesoilthroughmultiplecurvedtubestoenhancethekneadingeffect,andthemethodthatprovidepipesatmultipleplaceswithinthetubestosprayahardeningslurrysoastodirectlyaddthehardeningagentintothecohesivesoilasitpassesthroughthetube.

(4)Lightweighttreatedsoilmethodsmakedredgedsoilintoaslurrywithawatercontentattheliquidlimitorhigher,thenaddinacementhardenerandalightweightmaterialsuchasfoamorexpandedbeads.Thesemethodshavethefollowingcharacteristics:

① Thedredgedsoilisusedeffectively,evenunderwater,tocreateastableground.

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② Thedensity is from10 to12kN/m3, so this is effective in reducing the consolidation sedimentationof thefoundationgroundandinreducingtheearthpressure.

③ Theunconfinedcompressivestrengthisfrom200to600kN/m2,withthesamekindofmechanicalcharacteristicsashardclay. Thecostoflightweighttreatedsoilmethodsvariesgreatlydependingonthescopeoftheproject.Besidesthesemethods,therearealsomethodsthatperformdehydrationatdredgedsoildehydrationplantstopreparereclamationmaterial.

References

1) Takahashi,K.:UtilizationofFlyAshandSteelSlug,TechnicalNoteofPHRI,TechnicalNoteofPHRI2) NipponSlagAssociation:Characteristicsandversatilityofslag,19963) CoastalDevelopmentInstituteofTechnology(CDIT)andNipponSlagAssociation:Guidelinefortheutilizationofgranulated

blastfurnaceslagforportconstruction,19894) Port andAirportRecyclingPromotionForum:Technical guideline for recycling technology indevelopment of port and

airports,(http//:www.mlit.go.jp/kowan/recycle/),20045) Muraoka,T.:ReportoftestconstructionofCellulartypeseawallutilizingsteelmanufactureslag,CivilEngineeringdata,

Vol.51,No.7,19966) Kitazume,MS.MiyajimaandY.Nishida:LoadingtestofbackfillofSCPimprovedsoilbycoppergranulatedslag,Proceeding

the50thConferenceofJSCE,19957) Kitazume,M. :EffectofSCP improvementof soilbycoppergranulated slagon sheetpile seawall,Proceedingof31st

ConferenceonEarthquakeEngineering,19968) CoastalDevelopmentInstituteofTechnology:HandbookofutilizationofEco-Slugforportconstructionwork,CDIT,20069) CoastalDevelopmentInstituteofTechnology:TechnicalManualforironslughydrationhardener(enlargedEdition),200,10) Takahashi,K.:Geotechnicalexaminationonimprovementandreplacementofportfacilities,SoilandFoundation43-2(445),

SocietyofSoilMechanicsandEngineeringScience,199511) Ban,K.,J.AsanoandK.Takahashi:Mixproportionofcoalashindeepmixingmethodandengineeringcharacteristicsof

improvedsoil,Proceedingof50thConferenceofJSCE,199512) A.Watanabe,K.TakahashiandK.Azuma:EngineeringCharacteristicsofImprovedSoilbyDeepMixingMethodUsing

CoalAsh,12thInternationalSymposium,AmericanCoalAshAssosiation,199713) Miura,M.,K.Okuda,H.Kondo,K.KawasakiandK.Suami:Fieldexperimentsofsandcompactionutilizinghardenedcoal

ash,Proceedingof50thConferenceofJSCE,199514) K.Okuda,H,KondoandM.Miura:UtilizationofSolidifiedCoalAshasaSubstituteforSandandStone,121hInternational

Symposium,AmericanCoalAshAssosiation,199715) Yokota,H.andS.Nakajima:ApplicabilityofRecyclableMaterials toPortandHarbourConstruction,TechnicalNoteof

PHRINo.824,199616) Tanaka,j.,T.Fukude.,H.HamadaandA.Dozono:AStudyonthePropertiesofConcretemixedwithCrushedConcreteas

Aggregate,Rept.ofPHRIVol.36,No3,pp.37-60,199717) Itou,M.,T.Fukude,T.YamajiandJ.Tanaka:AStudyonApplicabilityofRecycledConcretetoMarineStructuresVol.37,

No.4,199818) Mizukami,J.,Y.KikuchiandH.Yoshino:Characteristicsofconcretedebrisasrubbleinmarineconstruction,Technical

NoteofPHRINo.906,1998


–353–

8 Other Materials8.1 Plastic and Rubber

(1)Whenusingplasticsandrubbers,materialshallbeselectedappropriatelyinviewofthelocationandpurposeofuse,environmentalconditions,durability,andcost.

(2)Thefollowingareexamplesofapplicationsofplasticandrubberinportconstruction.1),2)

① GeosyntheticsGeosyntheticsisageneraltermthatincludesthegeotextiles,namelypolymermaterialproductsintheformofpermeablesheets, aswellasgeomembranes,whicharenonpermeablefilms.

(a) PermeablematerialsPermeablematerialsmaybewovenornon-woven.Woventypes,geowovens,arewovenintoamatrixwithperpendicularlycrossingwarpsandwoofs.Non-woventypes,non-wovengeotextiles,aretextilescreatedbyadhesionoffibers,interlockingadhesion,orboth.

(b)WatersealingmaterialsThefollowingareexamplesofapplicationsofgeosyntheticsinportconstruction.

(c) EmbankmentreinforcingWhenlayinggood-qualitysoilsoveralandreclaimedwithdredgedclay,asheetornetofgeosyntheticsisspreadeddirectlyoverthesurface.Itspurposeistoensurethepassageofheavymachinery,whilepreventingsubsidenceofgood-qualitysoils.4)Thenetmethodhasoftenbeenusedinrecentreclamationworkswithsoftground.5)

(d)PreventingwashingoutandscouringWhenusedasafiltermaterialwiththeaimofpreventingsandwashingout,asandinvasionpreventionclothisoftenlaidoutonthesurfaceofbackfillstoneoronthebackofrubblemoundofthequaywall,andundertheentirebottomoftherubblemound,orunderthepartoftheseasideofthemound.Itisalsousedasameasuretoscouringprevention.

② JointsealingmaterialsTheseincludesealplates,jointboards,andgroutingmaterialsusedin/onthejointsectionsofconcretestructures.

③ ExpandedpolystyreneThis is used for buoys, pontoon floats, and other civil engineering structures, on account of its lightness.Expandedpolystyrene(EPS)blocksandEPSbeadsareusedascivilengineeringmaterials. Generally,EPSblocksareusedtoreduceearthpressure,tocountersettlementinembankmentsonsoftground,andtoformthefoundationsoftemporaryroads.EPSbeadsaremixedwithcementoranothercementingmaterialtogetherwithsoilsandusedasalightweightmaterialinbackfilling,inordertoreducesettlementandearthpressure.8)

(3)Thestandardsforsandinvasionpreventionclothandplate,andrubbermatsnormallyusedtopreventscouring,pipingorinfiltationinportandharborfacilitiesareasfollows:

① SandinvasionpreventionclothSandinvasionpreventionclothusedtopreventinvasionofsoilintothebackfillwillnormallybedeterminedinconsiderationoftheconstructionsconditionssuchastheplacingmethodofbackfilling,theresidualwaterlevel,andthelevelingprecisionofbackfilling. Thecloththatislaidunderthebottomofrubblemoundstopreventwashingoutofthesubsoilwillnormallybedeterminedinconsiderationofthenaturalandconstructionconditionssuchasthewaveheight,tidalcurrent,andrubblesize. Tables 8.1.1 (a) and (b) list theminimumstandards forwoven andnonwovenmaterials under favorableexecutionconditions.

Table 8.1.1 (a) Minimum Standards for Sand Invasion Prevention Sheets (Nonwoven)

Type Thickness Tensilestrength Elongation Mass Remarks

Nonwovencloth 4.2mmorgreater 880N/5cmorgreater 60%orgreater 500g/m2or

greater JISL1908

Note:The thicknessof4.2mmorgreater isappliedfor theclothunder loadingof2kN/m2according toJISL1908.Withno loading, thethicknessshouldbe5mmorgreater.

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Table 8.1.1 (b) Minimum Standards for Sand Invasion Prevention Sheets (Woven)

Type Thickness Tensilestrength Elongation Remarks

Wovencloth 0.47mmorgreater 4,080N/5cmorgreater 15%orgreater JISL1908

② SandinvasionpreventionplatesThestandardthicknessoftheplatesusedtopreventscouringandthatusedfortheverticaljointsofcaisson5mm.TheplatesshouldmeetthestandardslistedinTable 8.1.2.Incoldregions,rubberplatesaresometimesused.Inthiscase,thevalueslistedinTable 8.1.3 besatisfied.

Table 8.1.2 Standards for Sand Invasion Prevention Plates (Soft Vinyl Chloride)

TestitemParticulars

StandardvaluesMethod Tensiledirection

Tensilestrength JISK6723TestsampleNo.1typedumbbell Lateral 740N/cmorgreater

Tearstrength JIS6252Testsampleuncutangleshape Longitudinal 250Norgreater

Elongation JISK6723TestsampleNo.1typedumbbell Lateral 180%orgreater

SeawaterresistanceTensilestrengthresidualratio JISK6773 Lateral 90%orgreaterSeawaterresistance

Elongationresidualratio JISK6773 Lateral 90%orgreater

Specificgravity JISK7112 − 1.2−1.5

StrippingstrengthJISK6256Width25×250mmStrip-shapedsample

Longitudinal 30N/cmorgreater

Table 8.1.3 Standards for Sand Invasion Prevention Plates (Rubber)

TestitemParticulars

StandardvalueMethod Tensiledirection

Tensilestrength JISK6328 − 4,400N/3cmorgreater

③ RubbermatsRubbermatsusedforenhancingfrictionmaybemadeofbrand-neworrecycledrubber.ThequalityiscommonlyaslistedinTables 8.1.4 and8.1.5.

Table 8.1.4 Quality of Recycled Rubber

Testitem Performance Testconditions/method

Physicaltests

BeforeagingTensilestrengthTearstrengthHardnessElongation

4.9MPaorgreater18N/mmorgreater55−70graduations160%orgreater

JISK6251JISK6252JISK6253JISK6251

Afteraging

TensilestrengthTearstrengthHardnessElongation

3.9MPaorgreater

Within±8ofpre-agingvalue140%orgreater

JISK6251 AgingtestsareaccordingtoJISK6257

JISK6253 Agingtemperature70°±1°JISK6251 Agingtime96-20hours


–355–

Table 8.1.5 Quality of Brand-New Rubber

Testitem Performance Testconditions/method

Physicaltests

BeforeagingTensilestrengthTearstrengthHardnessElongation

9.8MPaorgreater25N/mmorgreater70±5graduations250%orgreater

JISK6251JISK6252JISK6253JISK6251

Afteraging

TensilestrengthTearstrengthHardnessElongation

9.3MPaandabove

Within±8ofpre-agingvalue200%orgreater

JISK6251 AgingtestsareaccordingtoJISK6257

JISK6253 Agingtemperature70°±1°JISK6251 Agingtime96-20hours

Compressivepermanentstrain 45%orless JISK6262 Agingtemperature70°±1°Agingtime24-20hours

8.2 Painting Materials

(1)Thefollowingitemsshouldbeconsideredwhenselectingpaintingmaterials:

① Thepurposeofthepainting

② Thepropertiesandcharacteristicsofthepaintedsurface

③ Theperformanceandcompositionofthepaintingmaterial

④ Cost

⑤Maintenance

8.3 Grouting Materials8.3.1 General

(1)Thegroutingmethodsshallbeselectedbyexaminingthesiteconditionsandperformedinconsiderationoftheinfluenceonthesurroundingenvironment.

(2)Thegroutingmethodsareemployedtostrengthenthegroundortocutoffthegroundwaterflowbyfillingcrevicesinrocksorsubsoils,vacantspacesinoraroundstructures,orvoidsofcoarseaggregatewithgroutingmaterials.Variousgroutingmaterialsareusedaccordingtothecharacteristicsoftheobjecttobegrouted.

8.3.2 Properties of Grouting Materials

(1)Groutingmaterialsshallbeselectedinviewoftherequiredperformanceforthesubsoilstobegrouted.

(2)Thebasic properties requiredof groutingmaterials are the efficiencyof seepage,filling and coagulation, thestrengthandimpermeabilityofthestabilizedbody.Suitabilitywiththegroutingobjectisparticularlyaffectedbytheseepageefficiencyofthematerial. Fig. 8.3.1 showstheseepagelimitsofvariousgroutingmaterialsforsubsoilsinviewofgrain-sizedistribution.

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Gravel Sand Silt ClayCoarse Large Medium Ultra-

fineFine

20mm 10 5 2 2μ1 0.5 0.2 0.1 0.05 0.02 0.01 5μ

100%

90

80

70

60

50

40

30

20

10

0

Limits accordingto KaronLimits accordingto Karon

Cla

y,ce

men

tC

lay,

cem

ent

Silic

ate

gel

Silic

ate

gel

Spec

ial s

ilica

te g

elSp

ecia

l sili

cate

gel

Resin

Resin

Cla

yC

lay

Fig. 8.3.1 Seepage Limits of Grouting Materials for Subsoils in View of Grain-size Distribution 15)

8.4 Asphalt Concrete Mass

(1)Asphaltconcretemassisoftencollectedfrommanydifferentplaces,soithasvariousproperties.19)Thequalityofrecycledasphaltmixturesshowsmorevariationthanthatofbrand-newmixtures.Therefore,tohavethedesiredneedlepenetration,onetypicallyaddsbrand-newasphaltoradditiveswhenrecycling.

(2)Recycledasphaltmixturesthatareusedforthefoundationlayerorsurfacelayercanbehandledthesamewayasasphaltmixturesthatarepurelybrand-newmaterial.

8.5 Oyster Shell

Crushedoystershellwithasizeofatmost30mmwhenmixedwithsandinaratioof2to1involumecanbeusedtoimprovegroundmaterials.Thestrengthofsoilimprovementpilewithmixed-inoystershellisevaluatedasaboutthesameasthatofimprovementpilecomposedofsand.However,characteristicssuchaswatercontentratioandcompressionindexvarybasedontheparticlesizeswhentheoystershelliscrushedandonthemixingratiowithsand,sotheuseofoystershellrequiressufficientinvestigation,suchasbysoiltest.

References

1) JSCE,CivilEngineeringHandbook(ForthEdition),,pp.143-146,pp.150-151、19892) Okada,K.,S.AkashiandMaterialsforCivilEngineering(RevisedEdition)People’sScience,Kokumin-KagakuPublishing,

1995l3) IndustrialTechnologyServiceCenter:Compendiumofreinforcingmethodsforslopeandembankment,,p174,19954) IndustrialTechnologyServiceCenter:Compendiumofpracticalmeasuresforsoftground,pp.619-631,19935) SocietyofSoilMechanicsandEngineeringScience,HandbookofSoilMechanics,pp.1041-1043,19826) PortandHarbourBureau,MinistryofTransportEdition:GuidelineforPortsurveys(RevisedEdition),JapanPortAssociation,

pp.3-187-3-205,19877) Kamon,M.:PlasticBoardDrainMethod,Foundation,Vol.19,No,6,pp.19-24,19918) Kuraku,M:Characteristicsoflightweightembankmentmethodanditsapplications,Foundation,Vol.18No.12,pp.2-9,19909) Coastal Development Institute of Technology (CDIT):Manual of corrosion protection and repair for port and harbour

facilities(RevisedEdition),199710) JapanRoadAssociation:HandbookofPaintingandcorrosionprotectionofsteelbridge,200611) JapanRoadAssociation:Guidelineandcommentaryofcountermeasuresagainsttosaltdamagesforhighwaybridges(Draft),

198412) Terauchi,K.:StudyonDeteriorationandpaintingSpecificationofBridgeslocatedinPortArea,TechnicalNoteofPHRI

No.651,198913) Dodo,IEdition:Know-howofconstruction:.KindaiToshoPublishing,p.32,199714) ‘TentativeguidelinesonconstructionsutilizingChemicalgroutingmethod(GovernmentOrder),July15,1974SafetyControl

Bureau,MinistryofPublicWorks,No.146,1974


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15) Shimada,S.:Themostadvancedtechnologyofchemicalgroutingmethod,RikoToshoPublishing,,p.161,199516) JapanRoadAssociation:GuidelineforplantrecyclingofPavement,199217) JapanRoadAssociation:Guidelineforsurfacerecyclingmethod(Draft),198818) JapanRoadAssociation:Guidelineforsurfacerecyclingmethod(Draft),198719) Yokota,H.andS.Nakajima:ApplicabilityofRecyclableMaterialstoPortandHarbourConstruction,TechnicalNoteof

PHRINo.824,199620) Hashidate,Y., S. Fukuda, T.Okumura andM.Kobayashi: Engineering characteristics of sand containing oyster shells,

Proceedingsofthe28thConferenceofSoilMechanics,pp.869-872,199221) Hashidate,Y.,S.Fukuda,T.OkumuraandM.Kobayashi:Engineeringcharacteristicsofsandcontainingoystershellsand

utilizationforsandcompactionpiles,Proceedingsofthe29thConferenceofSoilMechanics,pp.869-872,199422) Nishizuka,N.:UtilizationofoystershellsforSCPmethod,Proceedingsof11thConferenceofPortandHarbourtechnology,

,pp.149-164,1994

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9 Friction Coefficient

(1)For thefrictioncoefficientofamaterialwhen thefrictional resistanceforceagainst theslidingofafacility iscalculated,thestaticfrictioncoefficientcanbeused.Inthiscasethefrictioncoefficientofthematerialshouldbeappropriatelyspecifiedbyconsideringfactorssuchasthecharacteristicsofthefacilityandthecharacteristicsofthematerial.

(2)ForthecharacteristicvaluesofthestaticfrictioncoefficientfortheperformanceverificationofportfacilitiesitisgenerallypossibletousethevaluesgiveninTable 9.1.Considerationisneededasthereusuallyisalargevariationwhenthefrictioncoefficientisrepeatedlymeasuredunderthesameconditions.ThevaluesshowninTable 9.1arekindofvaluesusedfromthepastexperience,andifavalueisnotshownherethenitispreferabletoperformexperimentstodetermineit.

(3)Thevalues shown inTable 9.1 arevaluesused toverify the stabilityof facilities against sliding, andcannotbeusedforpurposessuchasfordeterminingthefrictioncoefficientbetweenthesurfaceofapileandthesoilwhencalculatingthebearingcapacityofapile,orthefrictioncoefficientforverifyingthestabilityofaslopingbreakwater,orthefrictioncoefficientusedtocalculatethelaunchingofacaissononslope,orthefrictionangleofawalltocalculateearthpressure.ThevaluesshowninTable 9.1arethestaticfrictioncoefficientswhenastaticactionsoccur,buttherearenoappropriatereferencesforwhendynamicmotionsoccur,suchasthroughseismicforces,soinfactthesevaluesarealsousedinsuchcases.

Table 9.1 Characteristic Values for the Static Friction Coefficient

Concreteandconcrete 0.5

Concreteandbaserock 0.5

Underwaterconcreteandbaserock 0.7to0.8

Concreteandrubble 0.6

Rubbleandrubble 0.8

Timberandtimber 0.2(wet)to0.5(dry)

Frictionenhancementmatandrubble 0.75

Note1: Understandardconditionsthevalue0.8maybeusedforthecaseofunderwaterconcreteandbaserock.However,insituationssuch as if thebedrock isbrittleorhasmanycracks,or if thereareplaceswhere themovementof thesand thatcovers thebedrock is significant,thecoefficientcanbeloweredundersuchconditionstoabout0.7.Note2: Part III, Chapter 5, 2.2, Gravity-Type Quaywalls can be referred to for the friction coefficient in the performance verificationofcellularblocks.

(4)FrictionCoefficientforFrictionEnhancementMatsIntheperformanceverificationofportfacilities,ifamaterialsuchasabituminousmaterialorrubberisusedasafrictionenhancementmatthenthefrictioncoefficientmaybetakenas0.75,asshowninTable 9.1.Incoldareasaseparateinvestigationisrecommended.

(5)FrictionCoefficientforIn-SituConcreteThefrictioncoefficientforin-situconcretemustbeappropriatelyspecifiedbytakingintoaccountfactorssuchasthecharacteristicsofthematerialandthenaturalconditions.

(6)SlidingResistancebetweenBaseRockandPrepackedConcreteAsforfrictioncoefficientbetweenbaserockandprepackedconcrete,thevaluesofTable 9.1 canbeused.Itisalsopossibletosimilarlytreatothertypesofunderwaterconcreteotherthanprepackedconcrete.

References

1) Morihira,M.,T.KiharaandH.Horikawa:Frictioncoefficientofrubblemoundofcompositebreakwater,Proceedingsof25thConferenceonCoastalEng.,JSCE,pp,337-341,1978

2) Morihira,M.andK.Adachi:Frictioncoefficientofrubblemoundofcompositebreakwater(Secondreport),Proceedingsof26thConferenceonCoastalEng.,JSCE,pp.446-450,1979

3) JapanSocietyofMechanicalEngineersEdition:HandbookofmechanicalEngineering4) Ishii,Y.andT.Ishiguro:Steelpilemethod.Giho-doPublishing,19595) Yokoyama,Y.:Designandconstructionofsteelpiles,Sankai-doPublishing,19636) JapanRoadAssociation:Earthworkforroads-guidelineforconstructionofretainingwall,,pp.20-21,1999


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7) Kagawa,M.:Increaseoffrictioncoefficientofgravitystructures,Proceedingsofthe11thConferenceonCoastalEng.JSCE,pp.217-221,1964

8) Shinkai,E.,O.KiyomiyaandY.Kakizaki:frictioncoefficientofrubbermatsforenlargementoffriction,Proceedingsof52ndConferenceofJSCE,pp.354-355,1997

9) Onodera,Y.andY.Aoki:AStudyontheCoefficientofFrictionbetweenPrepackedConcreteandBedrock,TechnicalNoteofPHRINo.135,p.8,1972

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chapter 10 self weight and surcharge

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