chapter 10 self weight and surcharge

Download Chapter 10 Self Weight and Surcharge

Post on 02-Jan-2017

217 views

Category:

Documents

0 download

Embed Size (px)

TRANSCRIPT

  • 312

    TECHNICAL STANDARDS AND COMMENTARIES FOR PORT AND HARBOUR FACILITIES IN JAPAN

    Chapter 10 Self Weight and Surcharge

    Public NoticeSelf Weight and Surcharge

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

    [Technical Note]

    1 General

    (1)Whenverifyingtheperformanceofportfacilities,selfweightandsurchargeshallbeconsidered,asnecessary.

    (2)Selfweightandsurchargearedefinedrespectivelyasfollows.

    Selfweight:theweightofthestructureitself

    Surcharge:theweightloadedontopofthestructure.Thisisdividedintostaticloadandliveload.

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

    (b)LiveloadThefollowingshallbeconsideredasliveloadasnecessary,whenverifyingtheperformanceofportfacilities.

    1) trainload

    2) vehicleload

    3) cargohandlingequipmentload

    4) sidewalkliveload

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

    2 Self Weight

    (1)SelfWeightIntheperformanceverificationofthefacilitiestowhichthetechnicalstandardsapply,theselfweightmustbeappropriatelysetbasedontheunitweightofthematerial.

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

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

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

    313

    Table 2.1 Characteristic Values of Unit Weights of Materials 1)

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

    References

    1) JapanPortAssociation:HandbookofConstructionofportfacilities,p,140,1959

  • 314

    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

    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

    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

    315

    thepartialfactor0.5.

    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.

    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 CharacteristicValueofUnitWeightkN/m3Drypowdersnowcompressedunderownweight 1.2Drypoweredsnowsubjecttowindpressure 1.7

    Fairlywetsnowcompressedunderownweight 4.5Verywetsnowcompressedunderownweight 8.5

  • 316

    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

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

    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 ftinAllowance

    iin mmAllowance

    mm ftAllowance

    iin mmAllowancesmm ftin

    Allowancesin kg lb

    1AAA

    12,192 0-10 400-3/8 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 80

    -3/161AX

  • PART II AC

Recommended

View more >