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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
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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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE
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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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE
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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.
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE
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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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE
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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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 10 SELF WEIGHT AND SURCHARGE
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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.
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
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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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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.
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
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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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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)
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
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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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–343–
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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
(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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
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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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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)
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–349–
(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
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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
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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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–357–
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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
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
PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER 11 MATERIALS
–359–
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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TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN
Recommended