Bridge Design Manual M 23-50 Chapter 15 Structural Design

WSDOT Bridge Design Manual M 23-50.17 Page 15-i June 2017

15.1 Manual Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-115.1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-115.1.2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-1

15.2 BridgeConfigurationCriteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-215.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-215.2.2 RailroadCrossings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-215.2.3 DetourStructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-315.2.4 InspectionandMaintenanceAccess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-315.2.5 BridgeTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-415.2.6 AestheticDesignElements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-415.2.7 ArchitecturalDesignStandards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-515.2.8 Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-515.2.9 Design-BuilderUrbanDesignTeam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-515.2.10 AnalysisandDesignCriteriaforStructuralWideningsandModifications . . . . . . . . . . .15-615.2.11 BridgeSecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-6

15.3 Load Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-815.3.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-815.3.2 LoadFactorsandLoadCombinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-815.3.3 PermanentLoads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-815.3.4 LiveLoads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-915.3.5 NoiseBarrierWalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-10

15.4 SeismicDesignandRetrofit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1115.4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1115.4.2 WSDOTAdditionsandModificationstoAASHTOGuideSpecifications

forLRFDSeismicBridgeDesign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-1115.4.3 SeismicDesignRequirementsforBridgeModificationsandWideningProjects . . . . . . 15-2115.4.4 SeismicRetrofittingofExistingBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-23

15.5 Concrete Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2515.5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2515.5.2 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2515.5.3 DesignConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2715.5.4 Superstructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-2815.5.5 ConcreteBridgeDecks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-32

15.6 Steel Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3415.6.1 DesignConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3415.6.2 GirderBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3615.6.3 DesignofI-Girders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-3715.6.4 PlanDetails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-42

Chapter 15 Structural Design Requirements for Design-Build Contracts Contents

Contents

Page 15-ii WSDOT Bridge Design Manual M 23-50.17 June 2017

15.7 Substructure Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4515.7.1 GeneralSubstructureConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4515.7.2 FoundationModelingforSeismicLoads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4515.7.3 ColumnDesign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4715.7.4 Crossbeam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4915.7.5 AbutmentDesignandDetails . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-4915.7.6 AbutmentWingWallsandCurtainWalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5115.7.7 FootingDesign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5115.7.8 Shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5215.7.9 PilesandPiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5415.7.10 Concrete-FilledSteelTubes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-55

15.8 Walls and Buried Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5615.8.1 RetainingWalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5615.8.2 NoiseBarrierWalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-5915.8.3 BuriedStructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-60

15.9 Bearings and Expansion Joints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-6215.9.1 ExpansionJoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-6215.9.2 Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-67

15.10 Signs, Barriers, Bridge Approach Slabs, and Utilities . . . . . . . . . . . . . . . . . . . . . . . . . 15-7315.10.1 SignandLuminaireSupports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-7315.10.2 BridgeTrafficBarriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8015.10.3 AtGradeConcreteBarriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8115.10.4 BridgeTrafficBarrierRehabilitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8315.10.5 BridgeRailing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8415.10.6 BridgeApproachSlabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8415.10.7 TrafficBarrieronBridgeApproachSlabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8615.10.8 UtilitiesInstalledwithNewConstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8615.10.9 UtilityInstallationonExistingBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8915.10.10 ResinBondedAnchors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-8915.10.11 DrainageDesign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-90

15.11 Detailing Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9115.11.1 StandardPractices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9115.11.2 BridgeOfficeStandardDrawingsandOfficeExamples . . . . . . . . . . . . . . . . . . . . . . . 15-9515.11.3 PlanSheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9515.11.5 StructuralSteel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9715.11.6 AluminumSectionDesignations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-9915.11.7 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-99

15.12 Bridge Load Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-10015.12.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-10015.12.2 LoadRatingSoftware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-100

15.99 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-101

WSDOT Bridge Design Manual M 23-50.17 Page 15-1 June 2017

Structural Design Chapter 15 Requirements for Design-Build Contracts

15.1 Manual Description15.1.1 Purpose

ThischapterprovidesthecontractualrequirementsforstructuraldesignofWSDOTprojectsthatsupersedeAASHTOLRFD Bridge Design Specifications(LRFD)andAASHTOGuide Specifications for LRFD Seismic Bridge Design (SEISMIC).

15.1.2 SpecificationsThismanualandthefollowingAASHTOSpecificationsarethefoundationdesigncriteriaanddesignpracticedocumentsusedtodesignhighwaybridgesandstructuresinWashingtonState:• AASHTOLRFD• AASHTOSEISMIC• WSDOTStandard Plans M21-01–A-50SeriesStandardPlansforEmbankmentGeometryatBridgeEnds

http://www.wsdot.wa.gov/Design/Standards/

Structural Design Requirements for Design-Build Contracts Chapter 15

Page 15-2 WSDOT Bridge Design Manual M 23-50.17 June 2017

15.2 BridgeConfigurationCriteria15.2.1 General

A. Bridge Redundancy

BridgesubstructureshallhavethefollowingminimumnumberofcolumnstobeconsideredtoprovideconventionallevelsofredundancyinaccordancewithAASHTOLRFD Bridge Design Specification Section1.3.4:• Onecolumnminimumforroadwaywidths40′wideandunder.• Twocolumnsminimumforroadwaywidthsover40′to60′.• Threecolumnsminimumforroadwaywidthsover60′.

BridgesuperstructureshallhavethefollowingminimumnumberofwebstobeconsideredtoprovideconventionallevelsofredundancyinaccordancewithAASHTOLRFD Bridge Design SpecificationSection1.3.4:• Threewebsminimumforroadwaywidths32′andunder.• Fourwebsminimumforroadwaywidthsover32′.SeeBridgeStandardDrawing2.3-A2-1fordetails.

B. Bridge Deck Drainage

Roadwayandbridgedeckprofilesshallbeadjustedasmuchaspossibletoavoidhavingbridgedrainsonthebridge.Ifbridgegeometryissuchthatdrainsarerequired,thenumberofdrainsshouldbeminimizedasmuchaspossiblewhilestillprovidingabridgedeckdrainagedesignthatmeetsrequiredstandards.Thebridgedrainassemblyandsystemshallbedesignedforlowmaintenance.

15.2.2 Railroad CrossingsA. Horizontal Clearances

Forrailroadovercrossings,minimumhorizontalclearancesareasnotedbelow:

Railroad AloneFill Section 14′Cut Section 16′

Horizontalclearanceshallbemeasuredfromthecenteroftheoutsidetracktothefaceofpier.Whenthetrackisonacurve,theminimumhorizontalclearanceshallbeincreasedattherateof1½″foreachdegreeofcurvature.Anadditional8′ofclearanceforoff-trackequipmentshallonlybeprovidedwhenspecificallyrequestedbytherailroad.

B. Crash Walls

Crashwalls,whenrequired,shallbedesignedtoconformtothecriteriaoftheAREMA Manual.Todeterminewhencrashwallsarerequired,consultthefollowing:• UnionPacificRailroad,“GuidelinesforDesignofHighwaySeparationStructuresoverRailroad(OverheadGradeSeparation)”

• AREMA Manual • WSDOTRailroadLiaisonEngineer• TheRailroad

http://www.wsdot.wa.gov/bridge/structures/standarddrawings.htm#Prelim

http://www.wsdot.wa.gov/bridge/structures/standarddrawings.htm#Prelim

https://www.arema.org/publications/mre/


Chapter 15 Structural Design Requirements for Design-Build Contracts


C. Substructure

Forhighwayoverrailwaygradeseparations,thetopoffootingsforbridgepiersorretainingwallsadjacenttorailroadtracksshallbe2′ormorebelowtheelevationofthetopoftieandshallnothavelessthan2′ofcoverfromthefinishedground.Thefootingfaceshallnotbecloserthan10′tothecenterofthetrack.

15.2.3 Detour StructuresA. Live Load

See Section3.4

B. DetourbridgetrafficbarriershallbedesignedtomeettheapplicableAASHTOLRFD criteria.

15.2.4 Inspection and Maintenance AccessA. General

Bridgesshallbeconfiguredtoallowinspectorsdirectaccesstobearings,andaccesstowithin3-feetofsuperstructuresurfaces.SeealsoFigure2.3.11-1forunder-bridge-inspection-truckclearancerequirements.

B. Bearings

Adequateclearanceformaintenanceandinspectionofbearingsshallbeprovided.Theclearanceshallbeadequatetoinspect,removeandreplacethebearings.

Jackingpointsshallbeprovidedforbearingreplacement.Jackingpointsshallbedesignedtosupport200percentofthecalculatedliftingload.

C. Safety Cables and Anchors

Built-upplategirderbridgeswithgirders5-feetdeeporgreaterindepthshallbedetailedwithsafetycablesforinspectorswalkingthebottomflanges.Atlargegussetplatelocationsontrussbridges(3-feetwideorwider),cablesorlanyardanchorsshallbeplacedontheinsidefaceofthetrusssoinspectorscanutilizebottomlateralgussetplatestostandonwhiletraversingaroundthemaintrussgussetplates.

D. AbutmentSlopes

Slopesinfrontofabutmentsshallprovideenoughoverheadclearancetothebottomofthesuperstructuretoaccessbearingsforinspectionandpossiblereplacement(3-feetminimumforgirdertypebridgesand5-feetminimumforconcreteslabs).

E. Access and Lighting

1. Concrete Box and Prestressed Concrete TubGirders

See Section5.2.6fordesigncriteria.

2. CompositeSteelBoxGirders

See Section6.4.9fordesigncriteria.



3. AccessDoors,Lighting,ReceptaclesandPenetrations

AllAccessdoorsshallhaveaminimum2′-6″diameteror2′-6″squareclearopening.Lockboxlatchesshallbeinstalledonallaccessdoorsaccessiblefromgroundlevel.Accesshatchesshallswingintotheboxgirdersandshallbeplacedatlocationsthatdonotimpacttraffic.LightingandreceptaclerequirementsshallbeinaccordancewithWSDOT Design Manual Chapter1040.AirventsshallbeinaccordancewithFigures5.2.6-1and5.2.6-2.

Boxgirderpenetrations(ventsanddrainholes)greaterthanoneinchindiameterthroughtheexteriorshallbecoveredwithgalvanizedwiremeshscreentopreventverminandbirdsfromaccessingtheinterioroftheboxgirder.Thewiresshallhaveamaximumspacingof¼inchinbothdirections.

15.2.5 Bridge TypesBridgesshallconformtothefollowingsuperstructuredepth-to-spanratiosbasedonpastWSDOTexperience,supersedingAASHTOLRFDSection2.52.6.3.

TheoptionalliveloaddeflectionlimitsofAASHTOLRFDSections3.6.1.3.2and2.5.2.6.2shallbesatisfied.

Forbothsimpleandcontinuousspans,thespanlengthisthehorizontaldistancebetweencenterlinesofbearings.

RefertoSection2.2.4forsuperstructuredepthrequirementsforinspectionandmaintenanceaccess.

FortherequiredminimumdepthtospanratiosseeSection2.4.1.

15.2.6 Aesthetic Design ElementsTheprimarygoaloftheaestheticdesignistobuildvisualcompatibilitybetweenthenewelementsandtheircurrentsurroundings.Theexistingelements,alongwithproposedandexistingstructures,typicallyestablishanidentifiablevisualcharacteristic.Theseexistingelementssuchaslightingfixtures,railingsstreethardware,constructionmaterials,colors,andfinishes,aretobeincludedasanintegralpartofthenewconstructionprogram.Examplesofnewelementsmayincludebutarenotlimitedto:• Bridgestructuretype• Bridgestructuremajorelementssuchaspierandcrossbeamform• Bridgestructureminorelementssuchasrailingsandlightstandards• Retainingwallmaterials,configurationandfinishes• Noisewallmaterial,configurationandfinishes:asviewedfromthecorridor• Noisewalls:asviewedfromtheneighborhoods• Vistaviewpoints• Medianandroadsideplantingareas• Colorselection• OpportunitiesforcommunityfundedartinaccordancewithDesign Manual Chapter950

http://www.wsdot.wa.gov/Publications/Manuals/M22-01.htm

http://www.wsdot.wa.gov/publications/manuals/fulltext/M22-01/1040.pdf

http://www.wsdot.wa.gov/publications/manuals/fulltext/M22-01/1040.pdf




SomedesignelementsareplannedtobefunctionallyandvisuallyconsistentwithfeaturesintheProject’sadjacentstructures.Otherelementsbenefitbyretainingflexibilitywithinaconsistentpaletteofmaterials,colors,anddesignformsinordertoprovidethedesign-build-processflexibilityindevelopingpotentialsolution.

ThefinaldesignandconfigurationoftheseProjectfeaturesandotherfunctionalcomponentswillrequireongoingcommunication,review,andcoordinationbetweenthedesign-buildContractor’sdesignteamandWSDOT’sreviewteam.

15.2.7 Architectural Design StandardsTheRFPdocumentswillincludearchitecturalstandards.ThesewillaccommodatethefunctionalrequirementsofthepreferreddesignsolutionaswellasaddressthecontextualconditionsoftheProjectarea.Theywillbesensitivetocorridorcontinuityaswellasthescale,characterandtextureofthearea.

ThestandardswillprovideareferencefortheProject’scontextsensitivedesignandpassalongthefindingsoftheurbandesignanalysisconductedduringtheProject’splanningandearlydesignphases.ThestandardsdescribetheProject’surbandesignfeaturesandaideinthecreationofanattractivefacilitythatwillbefunctional,maintainableovertime,aswellasaddtothearea’svisualcharacter.

Dependingontheprojectcomplexity,thestandardsmaybehighlydetailedandprescriptiveortheymaybemoregeneralinnature,suchasasimplelistofcriteria.

15.2.8 MethodsThedesign-buildershallcomplywiththearchitecturalstandards.Thedesign-buildershallalsoberesponsivetotheexistingurbandesigndocumentsintheadjacentcorridors.

Thedesign-buildershallemploythehigheststandardofcarebyimplementingnationalbestpracticesinurbandesign.Themethodsshallinclude,butnotlimitedto,suchtechniquesaContextSensitiveDesign(CSS)andCrimePreventionThroughEnvironmentalDesign(CEPTED).

15.2.9 Design-Builder Urban Design TeamWhererequiredintheRFP,thedesign-buildershallincludeaestheticdesignteammemberresources.Thisshallincludeanexperiencedurbandesignercapableofworkingwithotherteammembersandtoaddressfinalcontextsensitivedesignissues,constructiondetails,andspecialprojectdesignfeatures.Theurbandesignershallbeanarchitectwithurbanprojectexperience.

ThearchitectshallbelicensedintheStateofWashingtonandberesponsibleforthecoordinationanddevelopmentoftheproject’sarchitecturalcomponents.Preferenceshallbegiventoateamwithanarchitectexperiencedinbridgearchitecture.PreferenceshallalsobegiventoteamswherethearchitecthasacurrentstandingwithprofessionalorganizationssuchastheAmericanInstituteofArchitects(AIA)ortheAmericanInstituteofCityPlanners(AICP).Thearchitectshallsealtheapplicabledesigndocuments.



WhenrequiredbytheRFP,andinordertoassureconsistencywiththeRFParchitecturaldesignstandards,thedesign-buildershallformanUrbanDesignTeam.Theteamshallconsistof,asaminimum,adesignbuilderprojecturbandesignmanager,aWSDOTBridgeandStructuresOfficeStructuresEngineer,theWSDOTStateBridgeandStructuresArchitectandtheRegionorHQPrincipalLandscapeArchitect.

15.2.10 AnalysisandDesignCriteriaforStructuralWideningsandModificationsThewideningofabridgeshallbeofasimilarsuperstructuretypeastheexisting.Theoverallappearanceandgeometricaldimensionsofthewideningshallbethesameorascloseaspossibletothoseoftheexistingstructure.Materialsusedintheconstructionofthewideningshallhavethesamethermalandelasticpropertiesasthematerialsintheoriginalstructure.Prestressedconcretegirdersmaybeusedtowidenexistingcast-in-placeconcretestructures.

Themembersofthewideningshallbeproportionedtoprovidesimilarlongitudinalandtransverseloaddistributioncharacteristicsastheexistingstructure.

Differentialsettlementbetweenthenewandexistingstructuresshallbetakenintoaccount.

Thedesignofthewideningshallconformtocurrentstandardsandnotthestandardsusedtodesignandconstructtheexistingstructure.Thestrengthoftheexistingstructureshallbecheckedutilizingcurrentdesignstandards.Existingcomponentsshallbestrengthenedasnecessarysothattheircapacity/demandratiosarenotworsened.SeismicdesignofbridgewideningsshallbeinaccordancewithSection4.3.

Diaphragmsforthewideningshallcoincidewithandbeparalleltotheexistingdiaphragms.

Falseworkforthewideningshallbesupportedfromtheexistingstructureifthewideningdoesnotrequireadditionalgirdersorsubstructure.Otherwise,falseworkforthewideningshallnotbesupportedfromtheexistingstructure.

Ifthewideningrequiresadditionalgirdersorsubstructure,aclosurestripshallbeprovided.Allfalseworksupportingthewideningshallbereleasedpriortoplacingconcreteintheclosurestrip.Formworksupportingtheclosurestripshallbesupportedfromtheexistingstructureandthewidening.

15.2.11 Bridge SecurityA. General

WhererequiredintheRFP,newbridgesshallbedesignedforsecurity.Bridgeabutmentsinparticularshallbedesignedtodeterinappropriatepublicuseandaccessbyillegalurbancampers.

TheDesign-BuildContractorshallcoordinatewiththeprojecturbandesignteamtoidentifydeterrencestrategies.TheprinciplesofCPTED(CrimePreventionThroughEnvironmentalDesign)shallbeemployedwithtwostrategicoptions.Thefirststrategyemploysnaturalsurveillanceandterritorialreinforcement.Forconditionswherethefirststrategyisnotfeasible,thenasecondstrategyshallbeprovided.Thesecondstrategyprovideshardarmoring,suchassecurityfences.



B. NaturalSurveillanceandTerritorialReinforcement

Thenaturalsurveillanceandterritorialreinforcementstrategyshallbeprovidedthroughthefollowing:

1. Thedistancefromthetopofabutmentwalltothefinishedgradeatthefaceofabutmentshallnotbelessthan10feetinheightand,

2. Horizontalgradedlandformshelvesattheabutmentfacebeneathsuperstructuresshallbeomittedand,

3. Alcovespaceswithintheabutment-superstructureinterfaceshallbeomittedand,

4. Unobstructedviewsforlawenforcementsurveillanceshallbeprovided.

C. HardArmoring

Thehardarmoringstrategyshallconsistofoneofthefollowingoracombinationofboth:

1. Asecurityfencesystemwithananti-cut,anti-climb,galvanizedsteelweldedwiremeshfabric.Thesteelweldedwiremeshfabricshallhaveaminimumwirespacingof½inchforhorizontalelementsand3inchesverticalelements.Theminimumwirediametershallbe0.162inch(8gauge)steelweldedwiremesh.ThefencesystemshallhavethecomponentsshowninFigure2.8.3-2. Thebridgesecurityfenceshallnotbeconnectiontothebridgesuperstructure.Thesecurityfencemaybeattachedtothebridgeabutment,curtainwalls,girderseatsorretainingwalls.

2. Curtainwallsmaybeusedinlieuofasecurityfencesystem.Castinplaceconcrete,precastconcrete,orconcretemasonryunitmaterialsmaybeconstructedascurtainwallsprovidedtheymeettheprojecturbandesigngoals.Figure2.8.3-1showsaschematicviewofthecurtainwalloption.



15.3 Load Criteria15.3.1 Scope

AASHTOLRFDshallbetheminimumdesigncriteriausedforallprojects.Additionalrequirements,exceptions,anddeviationsfromAASHTOLRFDrequirementsarecontainedherein.

15.3.2 Load Factors and Load CombinationsAvalueof1.0shallbeusedforhiinEquation3.4.1-1ofAASHTOLRFDexceptforthedesignofcolumnswhenaminimumvalueofgiisrequiredbyArticle3.4.1ofAASHTOLRFD.Insuchacase,hishallbe0.95.

StrengthIVloadcombinationshallnotbeusedforfoundationdesign.Forfoundationdesign,loadsshallbefactoredafterdistributionthroughstructuralanalysisormodeling.

ThedesignliveloadfactorfortheServiceIIILimitStateloadcombinationshallbeasfollows:

gLL=0.8whentherequirementsofSections5.6.1and5.6.2aresatisfiedandstressanalysisisbasedongrosssectionproperties.

gLL=1.0whentherequirementsofSections5.6.1and5.6.2aresatisfiedandstressanalysisisbasedontransformedsectionproperties.

InspecialcasesthatdeviatefromtherequirementsofSections5.6.1and5.6.2andhavebeenapprovedbytheWSDOTBridgeDesignEngineer,gLL,shallbeasspecifiedintheAASHTOLRFD.

TheServiceIIIliveloadfactorforloadratingshallbe1.0.

TheliveloadfactorforExtremeEvent-ILimitStateshallbe0.5.Thebaseconstructiontemperatureshallbetakenas64°FforthedeterminationofTemperatureLoad.

TheLoadFactorsforPermanentLoadsDuetoSuperimposedDeformationsareprovidedinTable3.53.Table3.5-3replacesTable3.4.1-3ofAASHTOLRFD.

15.3.3 Permanent LoadsThedesignunitweightsofcommonpermanentloadsshallbeasshowninTable3.8-1.

A. FutureDeckOverlayRequirement

StructuresthatwillbeconstructedwithdeckprotectionSystem1or4shallbedesignedtoaccountfora2″thickHMAoverlayplaceduniformlyovertheentiredeckarea.Thedesignneednotaccountfortheweightofthe2″thickHMAoverlaywithinthedeckareacoveredbyappurtenancessuchas,butnotlimitedto,sidewalksandtrafficbarriers,whichhaveadeadweightinexcessofthe2″thickHMAoverlay.



15.3.4 Live LoadsA. Design Live Load

Thedesignliveloadshallbe:• Fornewbridgesandbridgesthataremodifiedinsuchawaytoincludenewsubstructureelements–LiveloadinaccordancewithAASHTOLRFD

• Forbridgesmodifiedinsuchawaythatdonotincludenewsubstructureelements–Liveloadcriteriaoftheoriginaldesign

• Forbridgesusedfortemporarydetourorothertemporarypurposes–minimum75percentofHL-93liveloadinaccordancewithAASHTOLRFD

TheapplicationofdesignvehicularliveloadsshallbeasspecifiedinAASHTOLRFDSection3.6.1.3.Thedesigntandem,or“lowboy”,definedinLRFDSectionC3.6.1.1shallbeincludedinthedesignvehicularliveload.

• TheeffectofonedesigntandemcombinedwiththeeffectofthedesignlaneloadspecifiedinLRFDArticle3.6.1.2.4and,fornegativemomentbetweenthepointsofcontraflexureunderauniformloadonallspansandreactionsatinteriorsupports,shallbeinvestigatedadualdesigntandemspacedfrom26.0feetto40.0feetapart,measuredbetweenthetrailingaxleoftheleadvehicleandtheleadaxleofthetrailingvehicle,combinedwiththedesignlaneload.Forthepurposeofthisarticle,thepairsofthedesigntandemshallbeplacedinadjacentspansinsuchpositiontoproducemaximumforceeffect.Axlesofthedesigntandemthatdonotcontributetotheextremeforceeffectunderconsiderationshallbeneglected.

B. LiveLoadDeflectionEvaluation

Article2.5.2.6.2oftheAASHTOLRFDismandatoryinitsentirety.

C. DistributiontoSuperstructure

1. Crosssectionsa,e,k,andalsoiandjifsufficientlyconnectedtoactasaunitfromAASHTOLRFD Table 4.6.2.2.1-1

Theliveloaddistributionfactorshallbeasfollows:• Forexteriorgirderdesignwithslabcantileverlengthequalorlessthan40percentoftheadjacentinteriorgirderspacing,usetheliveloaddistributionfactorfortheadjacentinteriorgirder.Theslabcantileverlengthisdefinedasthedistancefromthecenterlineoftheexteriorgirdertotheedgeoftheslab.

• Forexteriorgirderdesignwithslabcantileverlengthexceeding40percentoftheadjacentinteriorgirderspacing,usetheleverrulewiththemultiplepresencefactorof1.0forsinglelanetodeterminetheliveloaddistribution.Theliveloadusedtodesigntheexteriorgirdershallnotbelessthantheliveloadusedfortheadjacentinteriorgirder.



• TherigidcrosssectionanalysisdescribedinAASHTOLRFDSectionC4.6.2.2.2dshallnotbeusedtodetermineliveloaddistributionunlessitcanbedemonstratedthattheeffectivenessofdiaphragmsonthelateraldistributionofvehicularliveloadcausesthecrosssectionofthestructuretodeflectandrotateasarigidcrosssection.

2. CrosssectionTypedfromAASHTOLRFDTable4.6.2.2.1-1

Thistypeofcrosssectionshallbedesignedasasingleunit.TheliveloadforceeffectsshallbethatofasinglelaneofliveloadmultipliedbytheproductoftheliveloaddistributionfactorforinteriorgirderscomputedinaccordancewithAASHTOLRFDandthetotalnumberofwebsinthecrosssection.ThecorrectionfactorforliveloaddistributionforskewedsupportsasspecifiedinAASHTOLRFDTables4.6.2.2.2e-1and4.6.2.2.3c1forshearshallapply.

3. Distribution to Substructure

Thenumberoftrafficlanestobeusedinthesubstructuredesignshallbedeterminedbydividingtheentireroadwayslabwidthby12-feet.Nofractionallanesshallbeused.Bridgedeckwidthsoflessthan24feetshallhaveaminimumoftwodesignlanes.

4. DistributiontoCrossbeam

Thedesignandloadratingshallbedistributedtothesubstructurebyplacingwheellinereactionsinalaneconfigurationthatgeneratesthemaximumforceeffectsinthesubstructure.LiveloadsareconsideredtoactdirectlyonthesubstructurewithoutfurtherdistributionthroughthesuperstructureasillustratedinFigure3.9-1.

Forsteelandprestressedconcretesuperstructurewheretheliveloadistransferredtosubstructurethroughbearings,crossframesordiaphragms,thegirderreactionmaybeusedforsubstructuredesign.

15.3.5 Noise Barrier WallsWindonNoiseWallsshallbeasspecifiedinAASHTOLRFDSections3.8.1,3.8.1.2.4,and15.8.2.


15.4 SeismicDesignandRetrofit15.4.1 General

ThischapterandtheAASHTO SEISMICarethefoundationseismicdesigncriteriadocumentsusedtodesignhighwaybridgesinWashingtonState.

ThischaptersupplementsandsupersedestheAASHTOLRFDbyprovidingWSDOTseismicdesigncriteria,policyandpractice.

TheimportanceclassificationsforallhighwaybridgesinWashingtonStateareclassifiedas“Normal”exceptforspecialmajorbridges.Specialmajorbridgesfittingtheclassificationsofeither“Critical”or“Essential”willbesodesignatedintheRFP.

15.4.2 WSDOTAdditionsandModificationstoAASHTOGuideSpecificationsfor LRFD Seismic Bridge Design

WSDOTmodificationstotheAASHTOSEISMICareasfollows:

A. Definitions

GuideSpecificationsArticle2

Reviseexistingdefinitionsandaddnewdefinitionsasfollows:• Oversized Pile Shaft Adrilledshaftfoundationthatislargerindiameterthanthesupportedcolumnandhasareinforcingcagelargerthanandindependentofthecolumn’sreinforcementcage.ThesizeoftheshaftshallbeinaccordancewithSection7.8.2.

• Owner Personoragencyhavingjurisdictionoverthebridge.ForWSDOTprojects,regardlessofdeliverymethod,theterm“Owner”intheseGuideSpecificationsshallbetheWSDOTBridgeDesignEngineerand/ortheWSDOTGeotechnicalEngineer.

B. EarthquakeResistingSystems(ERS)RequirementsforSeismicDesignCategories(SDCs)C and D

GuideSpecificationsArticle3.3

WSDOTGlobalSeismicDesignStrategies:• Type1 DuctileSubstructurewithEssentiallyElasticSuperstructure.Thiscategoryispermissible.

• Type2 EssentiallyElasticSubstructurewithaDuctileSuperstructure.Thiscategoryisnotpermissible.

• Type3 ElasticSuperstructureandSubstructurewithaFusingMechanismBetweentheTwo.Thiscategoryisnotpermissible.



ForType1ERSforSDCCorD,ifcolumnsorpierwallsareconsideredanintegralpartoftheenergy-dissipatingsystembutremainelasticatthedemanddisplacement,theforcestouseforcapacitydesignofothercomponentsshallbeaminimumof1.2timestheelasticforcesresultingfromthedemanddisplacementinlieuoftheforcesobtainedfromoverstrengthplastichinginganalysis.Becausemaximumlimitinginertialforcesprovidedbyyieldingelementsactingataplasticmechanismlevelisnoteffectiveinthecaseofelasticdesign,thefollowingconstraintsareimposed.

1. Unlessananalysisthatconsidersredistributionofinternalstructureforcesduetoinelasticactionisperformed,allsubstructureunitsoftheframeunderconsiderationandofanyadjacentframesthatmaytransferinertialforcestotheframeinquestionshallremainelasticatthedesigngroundmotiondemand.

2. Effectivemembersectionpropertiesshallbeconsistentwiththeforcelevelsexpectedwithinthebridgesystem.Reinforcedconcretecolumnsandpierwallsshallbeanalyzedusingcrackedsectionproperties.ForthispurposeinabsenceofbetterinformationorestimatedbyFigure5.6.2-1,amomentofinertiaequaltoone-halfthatoftheuncrackedsectionshallbeused.

3. Foundationmodelingshallbeestablishedsuchthatuncertaintiesinmodelingwillnotcausetheinternalforcesofanyelementsunderconsiderationtoincreasebymorethan10percent.

4. Whensite-specificgroundresponseanalysisisperformed,theresponsespectrumordinatesshallbeselectedsuchthatuncertaintieswillnotcausetheinternalforcesofanyelementsunderconsiderationtoincreasebymorethan10percent.

5. Thermal,shrinkage,prestressorotherforcesthatmaybepresentinthestructureatthetimeofanearthquakeshallbeconsideredtoactinasensethatisleastfavorabletotheseismicloadcombinationunderinvestigation.

6. P-Deltaeffectsshallbeassessedusingtheresistanceoftheframeinquestionatthedeflectioncausedbythedesigngroundmotion.

7. Jointsheareffectsshallbeassessedwithaminimumofthecalculatedelasticinternalforcesappliedtothejoint.

8. DetailingasnormallyrequiredineitherSDCCorD,asappropriate,shallbeprovided.

Useofexpectedmaterialstrengthsforthedeterminationofmemberstrengthsforelasticresponseofmembersispermitted.

TheuseofelasticdesigninlieuofoverstrengthplastichingingforcesforcapacityprotectiondescribedaboveshallonlybeconsideredifdesignerdemonstratesthatcapacitydesignofArticle4.11oftheAASHTOGuide Specifications for LRFD Bridge Seismic Designisnotfeasibleduetogeotechnicalorstructuralreasons.

Type3ERSmaybeconsideredonlyifType1strategyisnotsuitableandType3strategyhasbeendeemednecessaryforaccommodatingseismicloads.IsolationbearingsshallbedesignedinaccordancewiththeAASHTO Guide Specifications for Seismic Isolation.IsolationbearingsshallconformtoSection9.3.



LimitationsontheuseofERSandEREareshowninFigures4.2.2-1,4.2.2-2,4.2.2-3,and4.2.3-4.• Figure4.2.2-2Type6,connectionwithmomentreducingdetailshouldonlybeusedatcolumnbaseifprovednecessaryforfoundationdesign.AfixedconnectionatbaseofcolumnremainsthepreferredoptionforWSDOTbridges.

• Thedesigncriteriaforcolumnbasewithmomentreducingdetailshallconsiderallapplicableloadsatservice,strength,andextremeeventlimitstates.

• 4.2.2-3Types6and8arenotpermissiblefornon-liquefiedconfigurationandpermissibleforliquefiedconfiguration.

C. SeismicGroundShakingHazard


ForbridgesthatareconsideredcriticaloressentialornormalbridgeswithasiteClassF,theseismicgroundshakinghazardshallbedeterminedinaccordancewiththesitespecificprocedureinArticle3.4.3oftheAASHTOSEISMIC.

IncaseswherethesitecoefficientsusedtoadjustmappedvaluesofdesigngroundmotionforlocalconditionsareinappropriatetodeterminethedesignspectrainaccordancewithgeneralprocedureofArticle3.4.1(suchastheperiodattheendofconstantdesignspectralaccelerationplateau(Ts)isgreaterthan1.0secondortheperiodatthebeginningofconstantdesignspectralaccelerationplateau(To)islessthan0.2second),asite-specificgroundmotionresponseanalysisshallbeperformed.

ThespectralresponseparametersshallbedeterminedusingUSGS2014 Seismic Hazard Maps and Site Coefficients definedinSection4.2.3.

D. SelectionofSeismicDesignCategory(SDC)


ApushoveranalysisshallbeusedtodeterminedisplacementcapacityforbothSDCsCandD.

E. TemporaryandStagedConstruction


Forbridgesthataredesignedforareducedseismicdemand,thecontractplansshalleitherincludeastatementthatclearlyindicatesthatthebridgewasdesignedastemporaryusingareducedseismicdemandorshowtheAccelerationResponseSpectrum(ARS)usedfordesign.Noliquefactionassessmentrequiredfortemporarybridges.

F. Load and Resistance Factors


Useloadfactorsof1.0forallpermanentloads.Theloadfactorforliveloadshallbe0.0whenpushoveranalysisisusedtodeterminethedisplacementcapacity.Usealiveloadfactorof0.5forallotherextremeeventcases.Unlessotherwisenoted,allϕfactorsshallbetakenas1.0.



G. BalancedStiffnessRequirementsandBalancedFrameGeometryRecommendation

GuideSpecificationsArticles4.1.2and4.1.3

BalancedstiffnessbetweenbentswithinaframeandbetweencolumnswithinabentandbalancedframegeometryforadjacentframesarerequiredforbridgesinbothSDCsCandD.

H. SelectionofAnalysisProceduretoDetermineSeismicDemand


MinimumrequirementsfortheselectionoftheanalysisproceduretodetermineseismicdemandshallbeasspecifiedinTables4.2-1and4.2-2oftheGuideSpecifications,exceptProcedure1(EquivalentStaticAnalysis)shallnotbeusedforWSDOTBridges.

I. MemberDuctilityRequirementforSDCsCandD


In-groundhingingfordrilledshaftandpilefoundationsmaybeconsideredfortheliquefiedconfigurationifallowedbytheRFPCriteria.

J. Longitudinal Restrainers

GuideSpecificationsArticle4.13.1

Longitudinalrestrainersshallbeprovidedattheexpansionjointsbetweensuperstructuresegments.RestrainersshallbedesignedinaccordancewiththeFHWASeismic Retrofitting Manual for Highway Structure(FHWAHRT06032),Article8.4,theIterativeMethod.RestrainersshallbedetailedinaccordancewiththerequirementsofGuideSpecificationsArticle4.13.3andBridge Design Manual Section4.4.4.RestrainersmaybeomittedforSDCsCandDwheretheavailableseatwidthexceedsthecalculatedsupportlengthspecifiedinEquationC4.13.1-1.

Longitudinalrestrainersshallnotbeusedattheendpiers(abutments).

K. Abutments


Abutmentsarerevisedasfollows:

1. 5.2.1-General

Theparticipationofabutmentwallsinprovidingresistancetoseismicallyinducedinertialloadsmaybeconsideredintheseismicdesignofbridgeseithertoreducecolumnsizesorreducetheductilitydemandonthecolumns.Damagetobackwallsandwingwallsduringearthquakesmaybeconsideredacceptablewhenconsideringnocollapsecriteria,providedthatunseatingorotherdamagetothesuperstructuredoesnotoccur.Abutmentparticipationintheoveralldynamicresponseofthebridgesystemshallreflectthestructuralconfiguration,theloadtransfermechanismfromthebridgetotheabutmentsystem,theeffectivestiffnessandforcecapacityofthewall-soilsystem,andthelevelofacceptableabutmentdamage.Thecapacityoftheabutmentstoresistthebridgeinertialloadsshallbecompatiblewiththesoilresistancethatcanbereliably

http://www.fhwa.dot.gov/publications/research/infrastructure/bridge/06032/



mobilized,thestructuraldesignoftheabutmentwall,andwhetherthewallispermittedtobedamagedbythedesignearthquake.Thelateralloadcapacityofwallsshallbeevaluatedonthebasisofarationalpassiveearth-pressuretheory.

TheparticipationofthebridgeapproachslabintheoveralldynamicresponseofbridgesystemstoearthquakeloadingandinprovidingresistancetoseismicallyinducedinertialloadsmaybeconsideredifallowedbytheRFPCriteria.

2. 5.2.2-LongitudinalDirection

TheabutmentmaybeconsideredaspartoftheERSforacontinuoussuperstructure.IftheabutmentisconsideredaspartofthelongitudinalERS,theabutmentstiffnessandcapacityshallbedeterminedasillustratedschematicallyinFigure5.2.2-aforsemi-integralabutments,Figure5.2.2-b forL-shapedabutmentswithbackwallfuse,andFigure5.2.2-cforL-shapedabutmentswithoutbackwallfuse.


4.2.11 Abutments

(a)Semi-integralAbutment (b)L-shapeAbutmentBackwallFuses

(c)L-shapeAbutmentBackwallDoesNotFuse

Figure5.2.2- AbutmentStiffnessandPassivePressure EstimateBDM Figure 4.2.11-1

Wherethepassivepressureresistanceofsoilsbehindsemi-integralorL-shapeabut-mentswillbemobilizedthroughlargelongitudinalsuperstructuredisplacements,thebridgemaybedesignedwiththeabutmentsaskeyelementsofthelongitudinalERS.Abutmentsshallbedesignedtosustainthedesignearthquakedisplacements.Whenabutmentstiffnessandcapacityareincludedinthedesign,itshouldberecognizedthatthepassivepressurezonemobilizedbyabutmentdisplacementextendsbeyondtheactivepressurezonenormallyusedforstaticserviceloaddesign.Thisisillustrat-edschematicallyinFigures1aand1b. Dynamicactiveearthpressureactingontheabutmentneednotbeconsideredinthedynamicanalysisofthebridge. Thepassiveabutmentresistanceshallbelimitedto70%ofthevalueobtainedusingtheproceduregiveninArticle5.2.2.1.

5.2.2.1 - AbutmentStiffnessandPassivePressureEstimate

Abutmentstiffness,Keff inkip/ft,andpassivecapacity,Pp inkips,shouldbecharac-terizedbyabilinearorotherhigherordernonlinearrelationshipasshowninFigure5.2.2.1.Whenthemotionofthebackwallisprimarilytranslation,passivepressuresmaybeassumeduniformlydistributedovertheheight(Hw)ofthebackwallorenddiaphragm.Thetotalpassiveforcemaybedeterminedas:

Pp = pp Hw Ww (5.2.2.1-1)

where:


4.2.11 Abutments







Pp = pp Hw Ww (5.2.2.1-1)

where:


4.2.11 Abutments







Pp = pp Hw Ww (5.2.2.1-1)

where:

(a) Semi-integral Abutment (b) L-shape Abutment Backwall Fuses

(c) L-shape Abutment Backwall Does Not Fuse

AbutmentStiffnessandPassivePressureEstimateFigure 5.2.2

Abutmentsshallbedesignedtosustainthedesignearthquakedisplacements.Thepassiveabutmentresistanceshallbelimitedto70percentofthevalueobtainedusingtheproceduregiveninArticle5.2.2.1.

3. 5.2.2.1-AbutmentStiffnessandPassivePressureEstimate

Abutmentstiffness,Keffinkip/feet,andpassivecapacity,Ppinkips,shallbecharacterizedbyabilinearorotherhigherordernonlinearrelationshipasshowninFigure5.2.2.1.Whenthemotionofthebackwallisprimarilytranslation,passivepressuresmaybeassumeduniformlydistributedovertheheight(Hw)ofthebackwallorenddiaphragm.Thetotalpassiveforceshallbedeterminedas:

Pp = pp Hw Ww (5 .2 .2 .1-1)Where:

pp = passivelateralearthpressurebehindbackwallordiaphragm(ksf)Hw = heightofbackwallorenddiaphragmexposedtopassiveearth

pressure(feet)Ww = widthofbackwallordiaphragm(feet)



Pp = pp Hw Ww (5.2.2.1-1)

where:

pp =passivelateralearthpressurebehindbackwallordiaphragm(ksf)

Hw =heightofbackwallorenddiaphragmexposedtopassiveearthpressure(ft)

Ww =widthofbackwallordiaphragm(ft)

(a) Semi-integralAbutment (b): L-shapeAbutment

Figure5.2.2.1- CharacterizationofAbutmentCapacityandStiffnessBDM Figure 4.2.11-2

5.2.2.2- CalculationofBestEstimatePassivePressurePp

Ifthestrengthcharacteristicsofcompactedornaturalsoilsinthe"passivepressurezone"areknown,thenthepassiveforceforagivenheight,Hw, maybecalculatedus-ingacceptedanalysisprocedures.Theseproceduresshouldaccountfortheinterfacefrictionbetweenthewallandthesoil.Thepropertiesusedshallbethoseindicativeoftheentire"passivepressurezone"asindicatedinFigure1. Therefore,thepropertiesofbackfillpresentimmediatelyadjacenttothewallintheactivepressurezone maynotbeappropriateasaweakerfailuresurfacecandevelopelsewhereintheembank-ment.

ForL-shapeabutmentswherethebackwallisnotdesignedtofuse,Hw

shallconservativelybetakenasthedepthofthesuperstructure,unlessamorerationalsoil-structureinteractionanalysisisperformed.

Ifpresumptivepassivepressuresaretobeusedfordesign,thenthefollowingcriteriashallapply:

Pp = pp Hw Ww (5.2.2.1-1)

where:

pp =passivelateralearthpressurebehindbackwallordiaphragm(ksf)

Hw =heightofbackwallorenddiaphragmexposedtopassiveearthpressure(ft)

Ww =widthofbackwallordiaphragm(ft)

(a) Semi-integralAbutment (b): L-shapeAbutment

Figure5.2.2.1- CharacterizationofAbutmentCapacityandStiffnessBDM Figure 4.2.11-2

5.2.2.2- CalculationofBestEstimatePassivePressurePp

Ifthestrengthcharacteristicsofcompactedornaturalsoilsinthe"passivepressurezone"areknown,thenthepassiveforceforagivenheight,Hw, maybecalculatedus-ingacceptedanalysisprocedures.Theseproceduresshouldaccountfortheinterfacefrictionbetweenthewallandthesoil.Thepropertiesusedshallbethoseindicativeoftheentire"passivepressurezone"asindicatedinFigure1. Therefore,thepropertiesofbackfillpresentimmediatelyadjacenttothewallintheactivepressurezone maynotbeappropriateasaweakerfailuresurfacecandevelopelsewhereintheembank-ment.

ForL-shapeabutmentswherethebackwallisnotdesignedtofuse,Hw

shallconservativelybetakenasthedepthofthesuperstructure,unlessamorerationalsoil-structureinteractionanalysisisperformed.

Ifpresumptivepassivepressuresaretobeusedfordesign,thenthefollowingcriteriashallapply:

(a) Semi-integral Abutment (b) L-shape AbutmentCharacterizationofAbutmentCapacityandStiffness

Figure 5.2.2-14. 5.2.2.2-CalculationofBestEstimatePassivePressurePp Ifthestrengthcharacteristicsofcompactedornaturalsoilsinthe“passive

pressurezone”areknown,thenthepassiveforceforagivenheight,Hw,shallbecalculatedusingacceptedanalysisprocedures.Theseproceduresshouldaccountfortheinterfacefrictionbetweenthewallandthesoil.Thepropertiesusedshallbethoseindicativeoftheentire“passivepressurezone”asindicatedinFigure1.Therefore,thepropertiesofbackfillpresentimmediatelyadjacenttothewallintheactivepressurezonemaynotbeappropriateasaweakerfailuresurfacecandevelopelsewhereintheembankment.

ForL-shapeabutmentswherethebackwallisnotdesignedtofuse,Hwshallconservativelybetakenasthedepthofthesuperstructure,unlessamorerationalsoil-structureinteractionanalysisisperformed.

Ifpresumptivepassivepressuresaretobeusedfordesign,thenthefollowingcriteriashallapply:• Soilinthe“passivepressurezone”shallbecompactedinaccordancewith

Standard Specifications Section2-03.3(14)I.• Forcohesionless,nonplasticbackfill(finescontentlessthan30percent),thepassivepressureppshallbeassumedequalto2Hw/3ksfperfootofwalllength.

• Forothercases,includingabutmentsconstructedincuts,thepassivepressuresshallbedevelopedbyageotechnicalengineer.

5. 5.2.2.3-CalculationofPassiveSoilStiffness

Equivalentlinearsecantstiffness,Keffinkip/feet,isrequiredforanalyses.Forsemi-integralorL-shapeabutmentsinitialsecantstiffnessmaybedeterminedasfollows:

5.2.2.3- Calculation of Passive Soil Stiffness

Equivalentlinearsecantstiffness,Keff inkip/ft,isrequiredforanalyses.Forsemi-integralorL-shapeabutmentsinitialsecantstiffnessmaybedeterminedasfol-lows:

( )ww

peff HF

PK =1 (5.2.2.3-1)

where:

Pp =passivelateralearthpressurecapacity(kip)

Hw =heightofbackwall(ft)

Fw = thevalueofFw touseforaparticularbridgemaybefoundinTableC3.11.1-1oftheAASHTO LRFD Bridge Design Specifications.

ForL-shapeabutments,theexpansiongapshouldbeincludedintheinitialestimateofthesecantstiffnessasspecifiedin:

( )gww

peff DHF

PK

+=1 (5.2.2.3-2)

where:

Dg =widthofgapbetweenbackwallandsuperstructure(ft)

ForSDCsCandD,wherepushoveranalysesareconducted,valuesofPp andtheini-tialestimateofKeff1 shouldbeusedtodefineabilinearload-displacementbehavioroftheabutmentforthecapacityassessment.

5.2.2.4-Modeling Passive Pressure Stiffness in the Longitudinal Direction

Inthelongitudinaldirection,whenthebridgeismovingtowardthesoil, thefullpas-siveresistanceofthesoilmaybemobilized,butwhenthebridgemovesawayfromthesoilnosoilresistanceismobilized. Sincepassivepressureactsatonlyoneabutmentatatime,linearelasticdynamicmodelsandframepushovermodelsshouldonlyincludeapassivepressurespringatoneabutmentinanygivenmodel.Secantstiffnessvaluesforpassivepressureshallbedevelopedindependentlyforeachabut-ment.

(5 .2 .2 .3-1)

Where:Pp = passivelateralearthpressurecapacity(kip)Hw = heightofbackwall(feet)Fw = thevalueofFwtouseforaparticularbridgeisfoundinTableC3.11.1-1

oftheAASHTOLRFD.



ForL-shapeabutments,theexpansiongapshallbeincludedintheinitialestimateofthesecantstiffnessasspecifiedin:

5.2.2.3- Calculation of Passive Soil Stiffness

Equivalentlinearsecantstiffness,Keff inkip/ft,isrequiredforanalyses.Forsemi-integralorL-shapeabutmentsinitialsecantstiffnessmaybedeterminedasfol-lows:

( )ww

peff HF

PK =1 (5.2.2.3-1)

where:

Pp =passivelateralearthpressurecapacity(kip)

Hw =heightofbackwall(ft)

Fw = thevalueofFw touseforaparticularbridgemaybefoundinTableC3.11.1-1oftheAASHTO LRFD Bridge Design Specifications.

ForL-shapeabutments,theexpansiongapshouldbeincludedintheinitialestimateofthesecantstiffnessasspecifiedin:

( )gww

peff DHF

PK

+=1 (5.2.2.3-2)

where:

Dg =widthofgapbetweenbackwallandsuperstructure(ft)

ForSDCsCandD,wherepushoveranalysesareconducted,valuesofPp andtheini-tialestimateofKeff1 shouldbeusedtodefineabilinearload-displacementbehavioroftheabutmentforthecapacityassessment.

5.2.2.4-Modeling Passive Pressure Stiffness in the Longitudinal Direction

Inthelongitudinaldirection,whenthebridgeismovingtowardthesoil, thefullpas-siveresistanceofthesoilmaybemobilized,butwhenthebridgemovesawayfromthesoilnosoilresistanceismobilized. Sincepassivepressureactsatonlyoneabutmentatatime,linearelasticdynamicmodelsandframepushovermodelsshouldonlyincludeapassivepressurespringatoneabutmentinanygivenmodel.Secantstiffnessvaluesforpassivepressureshallbedevelopedindependentlyforeachabut-ment.

(5 .2 .2 .3-2)

Where:Dg = widthofgapbetweenbackwallandsuperstructure(feet)

ForSDCsCandD,wherepushoveranalysesareconducted,valuesofPpandtheinitialestimateofKeff1shouldbeusedtodefineabilinearload-displacementbehavioroftheabutmentforthecapacityassessment.

6. 5.2.3-TransverseDirection

TransversestiffnessofabutmentsmaybeconsideredintheoveralldynamicresponseofbridgesystemsifallowedbyRFPCriteria.Thetransverseabutmentstiffnessusedintheelasticdemandmodelsshallbetakenas50-percentoftheelastictransversestiffnessoftheadjacentbent.

Girderstopsareexpectedtofuseatthedesigneventearthquakelevelofaccelerationtolimitthedemandandcontrolthedamageintheabutmentsandsupportingpiles/shafts.Theforcesgeneratedwithelasticdemandassessmentmodelsshallnotbeusedtosizetheabutmentgirderstops.Girderstopsforabutmentssupportedonaspreadfootingshallbedesignedtosustainthelesseroftheaccelerationcoefficient,As,timesthesuperstructuredeadloadreactionattheabutmentplustheweightofabutmentanditsfootingorslidingfrictionforcesofspreadfootings.Girderstopsforpile/shaft-supportedfoundationsshallbedesignedtosustainthesumof75percenttotallateralcapacityofthepiles/shaftsandshearcapacityofonewingwall.

Thestiffnessoffusingorbreakawayabutmentelementssuchaswingwalls(yieldingornon-yielding),elastomericbearings,andslidingfootingsshallnotbereliedupontoreducedisplacementdemandsatintermediatepiers.

Unlessfixedbearingsareused,girderstopsshallbeprovidedbetweenallgirdersregardlessoftheelasticseismicdemand.Thedesignofgirderstopsshallaccommodateunequalforcesthatmaydevelopineachstop.

Whenfusinggirderstops,transverseshearkeys,orotherelementsthatpotentiallyreleasetherestraintofthesuperstructureareused,thenadequatesupportlengthmeetingtherequirementsofArticle4.12oftheAASHTOSEISMICshallbeprovided.Additionally,theexpectedredistributionofinternalforcesinthesuperstructureandotherbridgesystemelementshallbeconsidered.Boundinganalysesconsideringincrementalreleaseoftransverserestraintateachendofthebridgeshallalsobeconsidered.

7. 5.2.4-CurvedandSkewedBridges

Thepassivepressureresistanceinsoilsbehindsemi-integralorL-shapeabutmentsshallbebasedontheprojectedwidthoftheabutmentwallnormaltothecenterlineofthebridge.Abutmentspringsshallbeincludedinthelocalcoordinatesystemoftheabutmentwall.



L. Foundation – General


TherequiredFoundationModelingMethod(FMM)andtherequirementsforestimationoffoundationspringsforspreadfootings,pilefoundations,anddrilledshaftsshallbeModelingMethodIIasdefinedinTable5.3.1-1.

M.Foundation–SpreadFooting

GuideSpecificationsArticleC5.3.2

FoundationspringsforspreadfootingsshallbedeterminedinaccordancewithSection7.2.7 andGeotechnical Design Manual Section6.5.1.1.

N. Procedure3:NonlinearTimeHistoryMethod


ThetimehistoriesofaccelerationusedtodescribetheearthquakeloadsshallbeselectedinaccordancewithGeotechnical Design ManualSection6-A.6.

O. IeffforBoxGirderSuperstructure


Thegrossmomentofinertiashallbeusedforboxgirdersuperstructuremodeling.

P. Foundation Rocking


FoundationrockingshallnotbeusedforthedesignofWSDOTbridges.

Q. Drilled Shafts

GuideSpecificationsArticleC6.5

ForWSDOTbridges,thescalefactorforp-ycurvesorsubgrademodulusforlargediametershaftsshallnotbeused.

R. LongitudinalDirectionRequirements


Case2:EarthquakeResistingSystem(ERS)withabutmentcontributionmaybeusedprovidedthatthemobilizedlongitudinalpassivepressureisnotgreaterthan70percentofthevalueobtainedusingtheproceduregiveninArticle5.2.2.1.

S. LiquefactionDesignRequirements


SoilliquefactionassessmentshallbebasedonGeotechnical Design Manual Section6.4.2.8.

T. Reinforcing Steel


Reinforcingbars,deformedwire,cold-drawwire,weldedplainwirefabricandweldeddeformedwirefabricshallconformtothematerialstandardsasspecifiedinAASHTOLRFD.






SteelreinforcementshallconformtoStandard Specifications Section9-07.2andthefollowingcriteria.OnlyASTMA706Grade60reinforcingsteelshallbeusedinmemberswhereplastichingingisexpectedforSDCsB,C,andD.ASTMA706Grade80reinforcingsteelsmaybeusedforcapacity-protectedmembersasspecifiedinArticle8.9.ASTMA706Grade80reinforcingsteelshallnotbeusedforoversizedshaftswherein-groundplastichingingisconsideredasapartofERS.

Deformedweldedwirefabricshallnotbeused.

Wireropeorstrandsforspiralsandhighstrengthbarswithyieldstrengthinexcessof75ksishallnotbeused.

GuideSpecificationsArticleC8.4.1

TherequirementsforplastichingingandcapacityprotectedmembersdonotapplytothestructuresinSDCA,thereforeuseofASTMA706Grade80reinforcingsteelispermittedinSDCA.

ForSDCsB,C,andD,themoment-curvatureanalysesbasedonstraincompatibilityandnonlinearstress/strainrelationsareusedtodeterminetheplasticmomentcapacitiesofallductileconcretemembers.Furtherresearchisrequiredtoestablishtheshapeandmodelofthestress-straincurve,expectedreinforcingstrengths,strainlimits,andthestress-strainrelationshipsforconcreteconfinedbylateralreinforcementmadewithASTMA706Grade80reinforcingsteel.

U. Concrete Modeling


Wherein-groundplastichingingispartoftheERS,theconfinedconcretecoreshallbelimitedtoamaximumcompressivestrainof0.008andthememberductilitydemandshallbelimitedto4maximum.

V. ExpectedNominalMomentCapacity


TheexpectednominalcapacityofcapacityprotectedmembersusingASTMA706Grade80reinforcementshallbedeterminedbystrengthdesignformulasspecifiedintheAASHTOLRFDbasedontheexpectedconcretestrengthandreinforcingsteelyieldstrengthswhentheconcretereaches0.003orthereinforcingsteelstrainreaches0.090for#10barsandsmaller,0.060for#11barsandlarger.

Replacethedefinitionofλmowiththefollowing:

λmo=overstrengthfactor

=1.2forASTMA706Grade60reinforcement

=1.4forASTMA615Grade60reinforcement

W. Interlocking Bar Size


Thelongitudinalreinforcingbarinsidetheinterlockingportionofacolumn(interlockingbars)shallbethesamesizeofbarsusedoutsidetheinterlockingportion.



X. SplicingofLongitudinalReinforcementinColumnsSubjecttoDuctilityDemandsforSDCsCandD


Thesplicingoflongitudinalcolumnreinforcementoutsidetheplastichingingregionshallbeaccomplishedusingmechanicalcouplersthatarecapableofdevelopingthetensilestrengthofthesplicedbar.Splicesshallbestaggeredatleast2feet.Lapsplicesshallnotbeused.Thedesignengineershallclearlyidentifythelocationswheresplicesinlongitudinalcolumnreinforcementarepermittedontheplans.Ingeneralwherethelengthoftherebarcageislessthan60feet(72feetforNo.14andNo.18bars),nospliceinthelongitudinalreinforcementshallbeallowed.

Y. DevelopmentLengthforColumnBarsExtendedintoOversizedPileShaftsfor SDCs C and D


ExtendingcolumnbarsintooversizedshaftshallbeinaccordancewithSection7.4.4.C,basedonTRACReportWARD417.1“Non-Contact Lap Splice in Bridge Column Shaft Connections”.

Z. LateralConfinementforOversizedPileShaftforSDCsCandD


Therequirementofthisarticleforshaftlateralreinforcementinthecolumn-shaftsplicezonemaybereplacedwiththerequirementsofSection7.8.2.K.

AA.LateralConfinementforNon-OversizedStrengthenedPileShaftforSDCsC and D


Non-oversizedcolumn-shaft(thecrosssectionoftheconfinedcoreisthesameforboththecolumnandthepileshaft)isnotpermissibleunlessallowedbytheRFPCriteria.

AB. RequirementsforCapacityProtectedMembers


ForSDCsCandDwhereliquefactionisidentified,pileanddrilledshaftingroundhingingmaybeconsideredasanERE.

Bridgesshallbeanalyzedanddesignedforthenon-liquefiedconditionandtheliquefiedconditioninaccordancewithArticle6.8.ThecapacityprotectedmembersshallbedesignedinaccordancewiththerequirementsofArticle4.11.Toensuretheformationofplastichingesincolumns,oversizedpileshaftsshallbedesignedforanexpectednominalmomentcapacity,Mne,atanylocationalongtheshaft,thatis,equalto1.25timesmomentdemandgeneratedbytheoverstrengthcolumnplastichingemomentandassociatedshearforceatthebaseofthecolumn.Thesafetyfactorof1.25maybereducedto1.0dependingonthesoilproperties.

http://www.wsdot.wa.gov/research/reports/fullreports/417.1.pdf



Thedesignmomentsbelowgroundforextendedpileshaftmaybedeterminedusingthenonlinearstaticprocedure(pushoveranalysis)bypushingthemlaterallytothedisplacementdemandobtainedfromanelasticresponsespectrumanalysis.Thepointofmaximummomentshallbeidentifiedbasedonthemomentdiagram.Theexpectedplastichingezoneshallextend3Daboveandbelowthepointofmaximummoment.Theplastichingezoneshallbedesignatedasa“nosplice”zoneandthetransversesteelforshearandconfinementshallbeprovidedaccordingly.

AC. SuperstructureCapacityDesignforTransverseDirection(IntegralBentCap)forSDCsCandD


ForSDCsCandD,thelongitudinalflexuralbentcapbeamreinforcementshallbecontinuous.Splicingofcapbeamlongitudinalflexuralreinforcementshallbeaccomplishedusingmechanicalcouplersthatarecapableofdevelopingthetensilestrengthofthesplicedbar.Splicesshallbestaggeredatleast2feet.Lapsplicesshallnotbeused.

AD. SuperstructureDesignforNonIntegralBentCapsforSDCsB,C,andD


NonintegralbentcapsshallnotbeusedforcontinuousconcretebridgesinSDCB,C,andDexceptattheexpansionjointsbetweensuperstructuresegments.

AE. IntegralBentCapJointShearDesign

GuideSpecificationsArticle8.13.4.1.1

InadditiontotheT-jointslistedinArticle8.13.4.1.1,theexteriorcolumnjointsforboxgirdersuperstructureandothersuperstructuresifthecapbeamextendsthejointfarenoughtodevelopthelongitudinalcapreinforcementshallbeconsideredT-jointsforjointshearanalysisinthetransversedirection.

AF. CastinPlace and Precast Concrete Piles


Minimumlongitudinalreinforcementof0.75percentofAgshallbeprovidedforCIPpilesinSDCsB,C,andD.Longitudinalreinforcementshallbeprovidedforthefulllengthofpile.

15.4.3 SeismicDesignRequirementsforBridgeModificationsandWidening Projects

A. SeismicAnalysisandRetrofitPolicy

TheSeismicAnalysisandRetrofitPolicyforBridgeModificationsandWideningProjectsshallconformtoSections 4.3.1 ,4.3.2,4.3.3,and4.3.4.

ThespectralresponseparametersshallbedeterminedusingUSGS2014SeismicHazardMapsandSiteCoefficientsdefinedinSection4.2.3.



B. Design and Detailing Considerations

1. SupportLength

Thesupportlengthatexistingabutments,piers,inspanhinges,andpavementseatsshallbechecked.Ifthereisaneedforlongitudinalrestrainers,transverserestrainers,oradditionalsupportlengthontheexistingstructure,theyshallbeincludedinthewideningdesign.

2. ConnectionsBetweenExistingandNewElements

Connectionsbetweentheexistingelementsandnewelementsshallbedesignedformaximumoverstrengthforces.Whereyieldingisexpectedinthecrossbeamconnectionattheextremeeventlimitstate,thenewstructureshallbedesignedtocarryliveloadsindependentlyattheStrengthIlimitstate.Incaseswherelargedifferentialsettlementand/oraliquefactioninducedlossofbearingstrengthareexpected,theconnectionsmaybedesignedtodeflectorhingeinordertoisolatethetwopartsofthestructure.Elementssubjecttoinelasticbehaviorshallbedesignedanddetailedtosustaintheexpecteddeformations.

Longitudinaljointsthatisolatethedecksbetweentheexistingandnewstructuresarenotpermitted.

3. DifferentialSettlement

Thedesignershallevaluatethepotentialfordifferentialsettlementbetweentheexistingstructureandwideningstructure.Additionalgeotechnicalmeasuresmayberequiredtolimitdifferentialsettlementstotolerablelevelsforbothstaticandseismicconditions.Thebridgedesignershallevaluate,design,anddetailallelementsofnewandexistingportionsofthewidenedstructureforthedifferentialsettlementwarrantedbythegeotechnicalengineer.Angulardistortionsbetweenadjacentfoundationsshallnotexceed0.008(RAD)insimplespansand0.004(RAD)incontinuousspans.

Thehorizontaldisplacementofpileandshaftfoundationsshallbeestimatedusingproceduresthatconsidersoilstructureinteraction(seeGeotechnical Design ManualSection8.12.2.3).Horizontalmovementcriteriashallbeestablishedatthetopofthefoundationbasedonthetoleranceofthestructuretolateralmovementwithconsiderationofthecolumnlengthandstiffness.Toleranceofthesuperstructuretolateralmovementwilldependonbridgeseatwidths,bearingtype(s),structuretype,andloaddistributioneffects.

4. FoundationTypes

Thefoundationtypeofthenewstructureshouldmatchthatoftheexistingstructure.However,adifferenttypeoffoundationmaybeusedforthenewstructureduetogeotechnicalrecommendationsorthelimitedspaceavailablebetweenexistingandnewstructures.Forexample,ashaftfoundationmaybeusedinlieuofspreadfooting.

5. ExistingStruttedColumns

Thehorizontalstrutbetweenexistingcolumnsmayberemoved.Theexistingcolumnsshallthenbeanalyzedwiththenewunbracedlengthsandretrofittedifnecessary.





6. NonStructuralElementStiffness

Medianbarriersandotherpotentiallystiffeningelementsshallbeisolatedfromthecolumnstoallowcolumndeformation.

DeformationcapacitiesofexistingbridgemembersthatdonotmeetcurrentdetailingstandardsshallbedeterminedusingtheprovisionsofSection7.8oftheRetrofitting Manual for Highway Structures: Part 1 – Bridges,FHWAHRT06032.DeformationcapacitiesofexistingbridgemembersthatmeetcurrentdetailingstandardsshallbedeterminedusingthelatesteditionoftheAASHTOSEISMIC.

Inlieuofspecificdata,thereinforcementpropertiesprovidedinTable4.3.2-1 shallbeused.

7. Isolation Bearings

Isolationbearingsmaybeusedforbridgewideningprojectstoreducetheseismicdemandthroughmodificationofthedynamicpropertiesofthebridge.IsolationbearingsshallbedesignedinaccordancewithAASHTOGuide Specifications for Seismic IsolationandshallconformtoSection9.3.

15.4.4 SeismicRetrofittingofExistingBridgesSeismicretrofittingofexistingbridgesshallbeperformedinaccordancewiththeFHWApublicationFHWAHRT06032,Seismic Retrofitting Manual for Highway Structures: Part 1 – Bridgesasfollows:• Article1.5.3ThespectralresponseparametersshallbedeterminedusingUSGS2014SeismicHazardMapsandSiteCoefficientsdefinedinSection4.2.3.

• Article7.4.2SeismicLoadinginTwoorThreeOrthogonal Revisethefirstparagraphasfollows: Whencombiningtheresponseoftwoorthreeorthogonaldirectionsthedesignvalueofanyquantityofinterest(displacement,bendingmoment,shearoraxialforce)shallbeobtainedbythe100-30percentcombinationruleasdescribedinAASHTOGuide SpecificationsArticle4.4.

• DeleteEq.7.44andreplacewiththefollowing:Lp=themaximumof[(8800εydb)or(0.08L+4400εydb)] (7-44)

• DeleteEq.7.49andreplacewiththefollowing:


6. NonStructuralElementStiffnessMedianbarriersandotherpotentiallystiffeningelementsshallbeisolatedfromthecolumnstoallowcolumndeformation.DeformationcapacitiesofexistingbridgemembersthatdonotmeetcurrentdetailingstandardsshallbedeterminedusingtheprovisionsofSection7.8oftheRetrofitting Manual for Highway Structures: Part 1 – Bridges,FHWA-HRT-06-032. DeformationcapacitiesofexistingbridgemembersthatmeetcurrentdetailingstandardsshallbedeterminedusingthelatesteditionoftheAASHTO Guide Specifications for LRFD Seismic Bridge Design.Inlieuofspecificdata,thereinforcementpropertiesprovidedinTable4.3.2-1shallbeused.

7. Isolation BearingsIsolationbearingsmaybeusedforbridgewideningprojectstoreducetheseismicdemandthroughmodificationofthedynamicpropertiesofthebridge.IsolationbearingsshallbedesignedinaccordancewithAASHTOGuide Specifications for Seismic Isolation andshallconformtoSection4.2.2.

15.4.4 Seismic Retrofitting of Existing BridgesSeismicretrofittingofexistingbridgesshallbeperformedinaccordancewiththeFHWApublicationFHWA-HRT-06-032, Seismic Retrofitting Manual for Highway Structures: Part 1 –Bridges asfollows:

• Article7.4.2SeismicLoadinginTwoorThreeOrthogonalDirectionsRevisethefirstparagraphasfollows:Whencombiningtheresponseoftwoorthreeorthogonaldirectionsthedesignvalueofanyquantityofinterest(displacement,bendingmoment,shearoraxialforce)shallbeobtainedbythe100-30percentcombinationruleasdescribedinAASHTO Guide SpecificationsArticle 4.4.



yfi

mip VV

VVφφ

+

−−

= 25

yjfji

jhjip VV

VVφφ

+

−

−= 24



6. NonStructuralElementStiffnessMedianbarriersandotherpotentiallystiffeningelementsshallbeisolatedfromthecolumnstoallowcolumndeformation.DeformationcapacitiesofexistingbridgemembersthatdonotmeetcurrentdetailingstandardsshallbedeterminedusingtheprovisionsofSection7.8oftheRetrofitting Manual for Highway Structures: Part 1 – Bridges,FHWA-HRT-06-032. DeformationcapacitiesofexistingbridgemembersthatmeetcurrentdetailingstandardsshallbedeterminedusingthelatesteditionoftheAASHTO Guide Specifications for LRFD Seismic Bridge Design.Inlieuofspecificdata,thereinforcementpropertiesprovidedinTable4.3.2-1shallbeused.

7. Isolation BearingsIsolationbearingsmaybeusedforbridgewideningprojectstoreducetheseismicdemandthroughmodificationofthedynamicpropertiesofthebridge.IsolationbearingsshallbedesignedinaccordancewithAASHTOGuide Specifications for Seismic Isolation andshallconformtoSection4.2.2.

15.4.4 Seismic Retrofitting of Existing BridgesSeismicretrofittingofexistingbridgesshallbeperformedinaccordancewiththeFHWApublicationFHWA-HRT-06-032, Seismic Retrofitting Manual for Highway Structures: Part 1 –Bridges asfollows:

• Article7.4.2SeismicLoadinginTwoorThreeOrthogonalDirectionsRevisethefirstparagraphasfollows:Whencombiningtheresponseoftwoorthreeorthogonaldirectionsthedesignvalueofanyquantityofinterest(displacement,bendingmoment,shearoraxialforce)shallbeobtainedbythe100-30percentcombinationruleasdescribedinAASHTO Guide SpecificationsArticle 4.4.



yfi

mip VV

VVφφ

+

−−

= 25

yjfji

jhjip VV

VVφφ

+

−

−= 24

https://www.fhwa.dot.gov/publications/research/infrastructure/bridge/06032/06032.pdf





A. SeismicAnalysisRequirements

Themulti-modespectralanalysisofSeismic Retrofitting ManualSection5.4.2.2(asaminimum)shallbeusedtodeterminetheseismicdisplacementandforcedemandstoidentifyseismicallydeficientelementsoftheexistingstructure.Prescriptiverequirements,suchassupportlength,shallbeconsideredmandatoryandshallbeincludedintheanalysis.SeismiccapacitiesshallbedeterminedinaccordancewiththerequirementsoftheSeismic Retrofitting Manual.DisplacementcapacitiesshallbedeterminedbytheMethodD2–StructureCapacity/Demand(Pushover)MethodofSeismic Retrofitting ManualSection5.6.Theseismicanalysisneedonlybeperformedfortheupperlevel(1,000yearreturnperiod)groundmotionswithalifesafetyseismicperformancelevel.

B. SeismicRetrofitDesign

Table111,Chapters8,9,10,11,andAppendicesDthruFoftheSeismic Retrofitting Manualshallbeusedinselectinganddesigningtheseismicretrofitmeasures.

C. Earthquake Restrainers

LongitudinalrestrainersshallbehighstrengthsteelrodsconformtoASTMF1554Grade105,includingSupplementRequirementsS2,S3andS5.Nuts,andcouplersifrequired,shallconformtoASTMA563GradeDH.WashersshallconformtoAASHTOM293.Highstrengthsteelrodsandassociatedcouplers,nutsandwashersshallbegalvanizedafterfabricationinaccordancewithAASHTOM232.Thelengthoflongitudinalrestrainersshallbelessthan24feet.

D. Isolation Bearings

Isolationbearingsmaybeusedforseismicretrofitprojectstoreducethedemandsthroughmodificationofthedynamicpropertiesofthebridgeasaviablealternativetostrengtheningweakelementsofnon-ductilebridgesubstructuremembersofexistingbridge.IsolationbearingsshallbedesignedinaccordancewiththerequirementoftheAASHTO Guide Specifications for Seismic IsolationandshallconformtoSection9.3.







15.5 Concrete Structures15.5.1 General

Designofconcretestructuresforroadwayelementssuchasbridges,lids,retainingwalls,noisewalls,three-sidedstructures,trafficbarrier,pedestrianbarrier,signstructures,bridgeapproachslabs,etc.shallbebasedontherequirementscitedhereinandinthecurrentAASHTOLRFD,AASHTOSEISMIC,WSDOTSpecialProvisionsandtheWSDOTStandard Specifications.

15.5.2 MaterialsA. Concrete

1. Cast-in-place(CIP)Concrete

Cast-in-place(CIP)concreteshallmeettherequirementsofTable5.1.1-1:

Component or Application

Minimum Numerical Class andMinimumCompressive

Strength at 28 days (psi)Letter Suffix

CompressiveStrength for use in Design = f’c (psi)

Commercial Concrete; Non-structural Concrete; Sidewalks; Curbs; Gutters

3000 - Numerical Class

General Structural Concrete including Spread Footings; Walls; Columns; Crossbeams; Box Girders; Slabs; Barriers; etc .

4000 - Numerical Class

Bridge Approach Slabs 4000 A Numerical ClassBridge Decks 4000 D Numerical ClassPiles and Shafts 4000/5000 P Numerical ClassUnderwater Seals 4000 W 0 .6 times Numerical

Class

Table 5.1.1-1

2. Modulus of Elasticity

Forcalculationofthemodulusofelasticity,theunitweightofplainconcrete(wc)shallbetakenas0.155kcfforprestressedconcretegirdersand0.150kcffornormal-weightconcreteunlessprojectspecificdataisavailable.Thecorrectionfactor(K1)shallbetakenas1.0unlessprojectspecificdataisavailable.

3. ShrinkageandCreep

Shrinkageandcreepshallbecalculatedwithrelativehumidity(H)takenas75percentunlessprojectspecificdataisavailable.Thematurityofconcrete(t)shallbetakenas2000days.Indeterminingtheageofconcreteattimeofloadapplication(ti)onedayofacceleratedcuringbysteamorradiantheatshallbetakenasequaltosevendaysofnormalcuring.




4. Grout

Groutpadswiththicknessexceeding4″shallbereinforcedwithsteelreinforcement.Non-shrinkgroutconformingtoStandard Specifications Section9-20.3(2)shallbeusedinkeywaysbetweenprestressedconcretegirders.

5. Mass Concrete

Concreteplacementswithaleastdimensionofgreaterthan6-feetshallbeconsideredmassconcrete,exceptthatshaftsneednotbeconsideredmassconcrete.

Thetemperatureofmassconcreteduringplacementandcuringshallnotexceed160°F.Thetemperaturedifferencebetweenthegeometriccenterofthemassconcreteandthecenterofnearbyexteriorsurfacesduringplacementandcuringshallnotexceed35°F.

AthermalcontrolplanshallbesubmittedbytheDesign-Builderforreviewandcommentformassconcreteplacements.Thethermalcontrolplanmayincludesuchthingsas:athermalanalysis;temperaturemonitorsandequipment;insulation;concretecoolingbeforeplacement;concretecoolingafterplacement,suchasbymeansofinternalcoolingpipes;useofsmaller,lessfrequentplacements;orothermethodsproposedbytheDesign-BuilderandacceptedbytheWSDOTEngineer.

Concretemixdesignsmaybeoptimized(suchasbyusinglow-heatcement,flyashorslagcement,low-water/cementratio,lowcementitiousmaterialscontent,largeraggregate,etc.)aslongastheconcretemixmeetsotherprojectrequirements.

6. Shotcrete

Shotcreteshallnotbeusedforpermanentstructures,includingexteriorwallfasciasurfaces,unlessallowedbyRFPCriteria.Shotcretemaybeusedfortemporaryapplications.

7. Lightweight Aggregate Concrete

Lightweightaggregateconcreteshallnotbeused,unlessallowedbyRFPCriteria.

B. Reinforcing Steel

1. Grades

SteelreinforcingbarsshallconformtoStandard Specifications Section9-07.2andSection15.4.2.T.UseofASTMA706Grade80steelreinforcingbarsshallconformtoSection5.1.2

2. CompressiveDevelopmentLength

Theminimumcompressivedevelopmentlengthshallbe1′-0″.

3. Splices

Minimumlapsplicelengths,forbothtensionandcompression,shallbe2′-0″.Whentwobarsofdifferentdiametersarelapspliced,thelengthofthelapspliceshallbethelargerofthelapspliceforthesmallerbarorthedevelopmentlengthforthelargerbar.

http://www.astm.org/Standards/A706.htm



4. WeldedWireReinforcementinPrestressedConcreteGirders,Walls,Barriers and Deck Panels

Weldedwirereinforcementmaybeusedtoreplacesteelreinforcingbarsinprestressedconcretegirders,walls,barriers,anddeckpanels.

Weldedwirereinforcementshallbedeformed.

Longitudinalwiresandweldsshallbeexcludedfromregionswithhighsheardemands,includinggirderwebs.Longitudinalwiresforanchorageofweldedwirereinforcementshallhaveanareaof40percentormoreoftheareaofthewirebeinganchoredasdescribedinASTMA497butshallnotbelessthanD4.

5. Reinforcing Bar Dowels and Resin Bonded Anchors

AllowabletensileloadsandminimumrequiredembedmentforreinforcingbardowelsshallbeinaccordancewithSection5.5.4.A.4.Ifitisnotpossibletoobtainthisembedment,theallowableloadonthedowelshallbereducedbytheratiooftheactualembedmentdividedbytherequiredembedment.

Beforecoredrilling,existingreinforcementshallbelocatedbynon-destructivemethodsorbychippingifexistingreinforcementcannotbedamaged.Coredrilledholesshallberoughened.

C. Prestressing Steel

PrestressingsteelshallbeAASHTOM203Grade270lowrelaxationforstrandsandAASHTOM275TypeIIforbars.

Therefinedestimateforcomputingtime-dependentlossesshallbeused.

Partialprestressingisnotpermitted.

15.5.3 Design ConsiderationsA. ServiceandFatigueLimitStates

TheexposurefactorforAASHTOLRFDSection 5.6.7“ControlofCrackingbyDistributionofReinforcement”shallbebaseduponaClass2exposurecondition.

ConcretestressesinprestressedmembersshallbelimitedtotheallowablestressesshowninTable5.2.1-1.

B. StrengthLimitState

ThesheardesignofprestressedmembersshallbebasedonthegeneralprocedureofAASHTOLRFDSection5.7.3.4.2.Thesheardesignofnon-prestressedmembersshallbebasedoneitherthegeneralprocedure,orthesimplifiedprocedureofAASHTOLRFDSection5.7.3.4.1.AASHTOLRFDSection5.8.3.4.3“SimplifiedProcedureforPrestressedandNon-prestressedSections”shallnotbeused.

Themaximumspacingofshearandtorsionreinforcementshallbe18inches.

C. Post-Tensioning

A2″minimumclearanceshallbeprovidedbetweenpost-tensioningductswithouterdiametergreaterthan3″.A1″minimumclearanceshallbeprovidedbetweenpost-tensioningductswithouterdiameterlessthanorequalto3″.

http://www.astm.org/Standards/A497.htm



Confinementreinforcementshallbeprovidedtoconfinecurvedpost-tensioningtendonsinaccordancewithSection5.8.1.F.

Thesizeoftheanchoragezoneintheplaneofanchorplatesshallbelargeenoughtoprovideaminimumof1″clearancefromtheplatestoanyfreeedge.

Structureshorteningeffectsduetopost-tensioningshallbeincludedinthedesign.

Thecambershallbeshownontheplansandshallincludetheeffectofbothdeadloadandfinalprestressing.

Allpost-tensioninganchoragesinwebsofboxgirderormulti-stemsuperstructureshallbeverticallyaligned.Tendonsadjacenttopost-tensioninganchoragesshallmeettheminimumtangentlengthandminimumtendonradiirequirementsofSection5.8.1.D.

15.5.4 SuperstructuresA. ReinforcedConcreteSuperstructures

TheuseofCIPreinforcedconcretebridgesuperstructureswithoutpost-tensioningshallberestrictedtowideningexistingreinforcedconcretebridgesuperstructures.Longitudinalpost-tensioningshallbeprovidedforallnewCIPreinforcedconcretebridgesuperstructures.

B. BoxGirderSuperstructures

1. IntermediateDiaphragmsforCurvedConcreteBoxGirderBridges

Intermediatediaphragmsshallbeprovidedforcurvedconcreteboxgirderbridgeswithcenterlineradius,R,lessthan800feet.Minimumdiaphragmspacingshallbeasfollows:

For600feet≤R<800feet-atmidspan.

For400feet≤R<600feet-at⅓pointsofspan.

ForR<400feet-at¼pointsofspan.

2. TemperatureEffects

Thermalstressesshallbeinvestigatedindesignusingthefollowingcriteria:

a. Ameantemperature50°Fwithrise45°Fandfall45°Fforlongitudinalanalysisusingone-halfofthemodulusofelasticity(MaximumSeasonalVariation.)

b. Thesuperstructureboxgirdershallbedesignedtransverselyforatemperaturedifferentialbetweeninsideandoutsidesurfacesof±15°Fwithnoreductioninmodulusofelasticity(MaximumDailyVariation).

c. Thesuperstructureboxgirdershallbedesignedlongitudinallyforatopslabtemperatureincreaseof20°Fwithnoreductioninmodulusofelasticity.



3. Drains

Drainsshallbeplacedinthebottomslabatthelowpointsofeachcell.DrainholedetailsshallbeinaccordancewithFigure5.3.8-1.

C. PrestressedConcreteGirderSuperstructures

1. WSDOTStandardGirderTypesandConstructionSequences

PrestressedconcretegirdersshallbeaWSDOTstandardgirdertypeinaccordancewithAppendices5.6-A1-1and5.6-A1-9.

PrestressedconcretegirdersuperstructuresshallfollowaconstructionsequenceinaccordancewithAppendix5.6-A1-2.

2. SuperstructureContinuity

Prestressedconcretegirdersuperstructuresshallbedesignedfortheenvelopeofsimplespanandcontinuousspanloadingsforallpermanentandtransientloads.Loadsappliedbeforeestablishingcontinuity(typicallybeforeplacementofcontinuitydiaphragms)needonlybeappliedasasimplespanloading.Continuityreinforcementshallbeprovidedatsupportsforloadsappliedafterestablishingcontinuity.

3. ContinuousStructureConfiguration

Girdertypesandspacingshallbeidenticalinadjacentspansoverintermediatepiers.Girdertypesandspacingmaybechangedatexpansionjoints.

4. Girder Ends

PrestressedconcretegirdersshallhaveastandardendtypeinaccordancewithSection5.6.2.E.PrestressingstrandsatgirderendsshallbeextendedintodiaphragmsandmadecontinuousinaccordancewithSection5.1.3.D.

Girderendskewanglesfortrapezoidaltub,slab,wideflangedeck,wideflangethindeckanddeckbulb-teeprestressedconcretegirdersshallbelimitedto30degrees.Girderendskewanglesforallotherprestressedconcretegirdersshallbelimitedto45degrees.

Thesplittingresistanceofpre-tensionedanchoragezonesshallbeasdescribedinAASHTOLRFDSection5.9.4.4.1.Theendverticalreinforcementshallnotbelargerthan#5barsandspacingshallnotbelessthan2½″.Theremainingsplittingreinforcementnotfittingwithintheh/4zonemaybeplacedbeyondtheh/4zoneataspacingof2½″.

5. Diaphragms

Diaphragmsforprestressedconcretegirdersuperstructuresshallbecast-in-placeconcrete.

Diaphragmsshallbeorientedparalleltogirdersupportskew.Oncurvedbridges,diaphragmsshallbeplacedonradiallines.IntermediateandenddiaphragmsshallbeinaccordancewithAppendices5.6-A1-1and5.6-A1-9.



Intermediatediaphragmsshallbeprovidedforallprestressedconcretegirderbridges(exceptslabs)atthefollowinglocations:• 1/5pointsofspanforspanlength>160′-0″.• ¼pointsofspanfor120′-0″<spanlength≤160′-0″.• ⅓pointsofspanfor80′-0″<spanlength≤120′-0″.• Midpointofspanfor40′-0″<spanlength≤80′-0″.• Nodiaphragmrequirementforspanlength≤40′-0″.

Intermediatediaphragmsshallbefulldepthforstructurescrossingoverroadswithaveragedailytraffic(ADT)greaterthan50,000,inaccordancewithSection5.6.4.C.4.

6. Barrier and Sidewalk Load Distribution

Thedeadloadofonetrafficbarrierorsidewalkshallnotbedistributedovermorethanthreegirderwebs.

7. CompositeAction

CompositesectionpropertiesincludingeffectiveflangewidthofthecompositedeckshallbeinaccordancewithSection5.6.2.B.

8. Dead Loads

Thebridgedeckdeadloadtobeappliedtoagirdershallbebasedonthefullbridgedeckthickness.Thepad/haunchweightduetothemaximumpad/haunchheightshallbeaddedtothatloadoverthefulllengthofthegirder.

Whenthedepthofthepad/haunchbetweenthetopoftheprestressedconcretegirderandtheundersideofthedeckatthecenterlineofthegirderexceeds6″,reinforcementshallbeprovidedinthepadinaccordancewithFigure5.6.4-2.

9. GirderStirrups

Girderstirrupsshallbefieldbentoverthetopmatofreinforcementinthebridgedeckunlesspre-benthooksareallowedbytheWSDOTstandardgirdertypeorthepre-benthooksarewithinthecoreoftheCIPdeck(theinsideedgeofthehookterminatesabovethebottommatofthedeckbars).

10.TransformedSectionProperties

Transformedsectionpropertiesshallnotbeusedfordesignofprestressedconcretegirders.Grosssectionpropertiesshallbeused.

11. Deck Shrinkage

TheelasticgaininprestressingstrandsduetoslabshrinkageshallbecomputedinaccordancewithAASHTOLRFDSection5.9.3.4.3.d.DeckshrinkageshallbeconsideredasanexternalforceappliedtothecompositesectionfortheServiceI,ServiceIII,andFatigueIlimitstates.Thedeckshrinkagestrainshallbecomputedas50-percentofthestraindeterminedbyAASHTOLRFDEquation5.4.2.3.3-1.



12. DeckGirderSuperstructures

Theterm“deckgirder”referstoaprestressedconcretegirderwhosetopflangeorsurfaceisthedrivingsurface,withorwithoutanoverlay,includingslabanddeckbulb-teegirders.

DeckgirderswithoutacompositeCIPdeckslabshallhaveaminimumconcretecoverof2″overthetopmat.Thetopmatofreinforcementinthetopflangeshallbeepoxy-coated.

13. Slab Girders

Slabgirderspansbetweencenterlinebearingsshallbelimitedtotheprestressedconcretegirderheightmultipliedby30.Aminimum5″compositeCIPbridgedeckshallbeplacedoverslabgirdersdirectlysupportingtrafficloadings.TheCIPconcretebridgedeckshallataminimumbeClass4000Dconcretewithonelayerof#5epoxycoatedreinforcementinboththetransverseandlongitudinaldirections.Thelongitudinalreinforcementshallbespacedat12inchesmaximumandthetransversereinforcementshallbespacedat6inchesmaximum.

14. Deck Bulb-Tee Girders

Deckbulb-teegirdersshallbelimitedtopedestrianbridges,temporarybridgesandtowideningexistingsimilarstructures.

Deckbulb-teegirdersshallhaveanHMAorconcreteoverlay.AwaterproofingmembraneshallbeprovidedwithanHMAoverlay.

15.WideFlangeDeckGirders

Wideflangedeckgirdersshallbelimitedtopedestrianbridges,temporarybridgesandtowideningexistingsimilarstructures.

WideflangedeckgirdersshallhaveanHMAorconcreteoverlay.AwaterproofingmembraneshallbeprovidedwithanHMAoverlay.

16. Wide Flange Thin Deck Girders

Wideflangethindeckgirdersshallhaveaminimum5″thickcompositeCIPbridgedeck.TheCIPconcretebridgedeckshallataminimumbeClass4000Dconcretewithonelayerof#5epoxycoatedreinforcementinboththetransverseandlongitudinaldirections.Thelongitudinalreinforcementshallbespacedat12inchesmaximumandthetransversereinforcementshallbespacedat6inchesmaximum.

17. Tub Girders

Drainsshallbeplacedinthecenterlineofthebottomflangeatthelowpointsofeachcell.DrainholedetailsshallbeinaccordancewithAppendices5.6-A1-1 and5.6-A1-9.

18.SplicedPrestressedConcreteGirders

ClosurejointsshallbeCIPconcretewithaminimumlengthof2′-0″.Thesequenceofplacingconcretefortheclosurejointsanddeckshallbespecifiedintheplans.

ConcretecovertowebstirrupsattheCIPclosureatpierdiaphragmsshallnotbelessthan2½″.IfintermediatediaphragmlocationscoincidewithCIPclosuresbetweenprecastsegments,thentheconcretecoverattheCIPclosuresshallnotbelessthan2½″.



15.5.5 Concrete Bridge DecksConcretebridgedecksshallbedesignedusingtheTraditionalDesignofAASHTOLRFDSection9.7.3.

Forwebspacinginexcessof12feetorcantileveroverhanginexcessof6feet,transversepost-tensioningshallbeprovidedinthedeck.

Forstructuresthatincludesidewalks,theconstructionjointbetweenthesidewalkandthedeckshallbeasmoothsurface.

Longitudinalexpansionorisolationjointsinbridgedecksarenotpermitted.

A. BridgeDeckRequirements

Theminimumbridgedeckthicknessshallbe5″forslabanddeckbulb-teeprestressedconcretegirdersuperstructures,7.5″forotherconcretesuperstructures,8.0″forsteelgirdersuperstructures,and8.5″(including3.5″stay-in-placedeckpaneland5″CIPconcretedeck)forsuperstructureswithSIPdeckpanels.Thisminimumthicknessmaybereducedby0.5″forbridgeswithDeckProtectionSystems2,3and5.

Thedistancefromthetopofthebridgedecktothetopofthegirderatcenterlinebearingatcenterlineofgirderisrepresentedbythe“A”Dimension.ItshallbecalculatedandshownintheplansinaccordancewithAppendix5-B1.

Aroughenedsurfaceorashearkeyshallbeprovidedatdeckconstructionjoints.

B. BridgeDeckReinforcement

Toptransversereinforcementshallbehookedatthedeckslabedgeunlessatrafficbarrierisnotused.

LongitudinaldeckslabreinforcementshallbeprovidedinaccordancewithSection5.7.2.B.

Theminimumclearancebetweentopandbottomreinforcingmatsshallbe1″.

TheminimumcoveroverthetoplayerofreinforcementshallbeinaccordancewiththeappropriateDeckProtectionSystem.Theminimumcoverbelowthebottomlayerreinforcementshallbe1.0″.

Theminimumamountofreinforcementineachdirectionshallbe0.18in2/feetforthetopmatand0.27in2/feetforthebottommat.

Themaximumbarspacinginbothtransverseandlongitudinaldirectionsforthetopmat,andtransversedirectionofthebottommatshallnotexceed12″.Themaximumbarspacingforthebottomlongitudinaldirectionwithintheeffectivelength,asspecifiedinAASHTOLRFDSection9.7.2.3,shallnotexceedthedeckthickness.



C. Stay-in-Place(SIP)DeckPanels

SIPdeckpanelsshallbeprecastconcreteandtheirdetailsshallbeinaccordancewithBridgeStandardDrawing5.6-A10-1.SIPsteeldeckformsarenotpermitted.

SIPdeckpanelsshallnotbeusedinlongitudinalnegativemomentregionsofcontinuoussuperstructures,unlessthedeckislongitudinallypost-tensioned.

Forabridgewideningorphasedconstruction,SIPdeckpanelsshallnotbeusedinthebayadjacenttotheexistingstructure.

SIPdeckpanelsshallnotbeusedonprestressedconcretegirderswithflangeslessthan12″wide.

SIPdeckpanelsshallnotbeusedonsteelgirderbridgesuperstructures.

D. Bridge Deck Protection

Allnewbridgedecks,precastorcast-in-placeslabs,anddeckgirderstructuresshallutilizeadeckprotectionsysteminaccordancewiththissectionandSection5.7.4.A.WideningofexistingbridgedecksandslabbridgesshallbeinaccordancewithSection5.7.4.B.

E. Bridge Deck HMA Paving

Asphaltresurfacingincludingbituminoussurfacetreatment(BST)onbridgedecksandslabbridgesshallbeinaccordancewiththeBridgedeckConditionReport(BCR)providedforeachbridge.ConstructionshallbeinaccordancewiththebridgepavingspecificationsincludedintheRFP.

http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#SIP



15.6 Steel Structures15.6.1 Design Considerations

A. Codes,Specification,andStandards

Steelhighwaybridgesshallbedesignedtothefollowingcodesandspecifications:• AASHTOLRFD,latestedition• AASHTOSEISMIC

Thefollowingcodesandspecificationsshallgovernsteelbridgeconstruction:• WSDOTStandard Specifications,latestedition• AASHTO/AWSD1.5M/D1.5:Bridge Welding Code,latestedition

B. WSDOT Steel Bridge Practice

Unshoredcompositeconstructionisusedforplategirderandboxgirderbridges.Shearconnectorsshallbeplacedthroughoutpositiveandnegativemomentregions,forfullcompositebehavior.Aminimumofonepercentlongitudinaldecksteel,inaccordancewithAASHTOLRFDArticle6.10.1.7,shallbeplacedinnegativemomentregions.Forservicelevelstiffnessanalysis,suchascalculatingliveloadmomentenvelopes,thebridgedeckshallbeconsideredcompositeanduncrackedfortheentirebridgelength.Fornegativemomentatstrengthlimitstates,thebridgedeckshallbeignoredwhilereinforcingsteelisincludedforstressandsectionpropertycalculations.

Stiffenersusedtoconnectcrossframesshallbeweldedtotopandbottomflanges.Jackingstiffenersshallbeusedadjacenttobearingstiffeners,ongirderordiaphragmwebs,inordertoaccommodatefuturebearingreplacement.Coordinatejackplacementinsubstructureandgirderdetails.

Steelframingshallconsistofmaingirdersandcrossframes.Bottomlateralsystemsshallonlybeusedwhenrequiredfortorsionalstabilityincurvedbridgesandwhentemporarybracingisnotpractical.Whenlateralsystemsareused,theyshallbedetailedcarefullyforadequatefatiguelife.

StandardcorrosionprotectionforsteelbridgesistheStandard Specifications four-coatpaintsystemwestoftheCascadesandwherepaintisrequiredforappearance.UnpaintedweatheringsteelshallonlybeusedeastoftheCascades.

WSDOTdoesnotallowtheuseofsteelstay-in-placedeckforms.

C. PreliminaryGirderProportioning

LiveloaddeflectionsshallbelimitedinaccordancewiththeoptionalcriteriaofAASHTOLRFDArticles2.5.2.6.2and3.6.1.3.2.

Thesuperstructuredepthshallbeshownasthedistancefromthetopofthebridgedecktothebottomoftheweb.Onstraightbridges,interiorandexteriorgirdersshallbedesignedanddetailedasidentical.Spacingshouldbesuchthatthedistributionofwheelloadsontheexteriorgirderisclosetothatoftheinteriorgirder.Thenumberofgirderlinesshouldbeminimized,withamaximumspacingof14-16feet.Steelbridgesshallberedundant,withthreeormoregirderslinesforIgirdersandtwoormoreboxesforboxgirders,exceptasotherwiseallowedbytheRFPCriteria.




D. Bridge Steels

UseAASHTOM270/ASTMA709grades50or50Wforplategirdersandboxgirders.UseofAASHTOM270/ASTMA709GradeHPS70Wispermissiblebutavailabilityislimitedandshallbeconfirmedpriortoactualuseindesign.AASHTOM270gradesHPS50WandHPS100WmayonlybeusedifallowedbytheRFPCriteria.Forwideflangebeams,useAASHTOM270/ASTMA709Grade50S or ASTMA992.Forancillarymemberssuchasexpansionjointheaders,utilitybrackets,bearingcomponentsorsmallquantitiesoftees,channels,andangles,ASTMM270/ASTMA709bridgesteelsareacceptablebutarenotrequired.Inthesecases,equivalentASTMdesignatedsteelsmaybeused.

Allmainload-carryingmembersorcomponentssubjecttotensilestressshallbeidentifiedintheplansandshallmeettheminimumCharpyV-notch(CVN)fracturetoughnessvaluesasspecifiedinAASHTOLRFDTable6.6.2-2,temperaturezone2.Fracturecriticalmembersorcomponentsshallalsobedesignatedintheplans.

StructuraltubesandpipesarenotconsideredprequalifiedundertheBridge Welding Code.TheyarecoveredundertheStructuralWeldingCodeAWSD1.1.StructuraltubingASTMA500shallnotbeusedfordynamicloadingapplications.ASTMA1085isanewercoldformedandweldedHSSsectionspecificationthatisaGr50steel.SupplementsforheattreatingandCVNsareincludedandmayalsobespecified.CVNtestsaretypicallyperformedintheflatsoftheHSSsquareorrectangulartubesections.CVNvaluesinthebendradiusofthetubesarelowerthanvaluesobtainedintheflats.Heattreatingofthesectionscanimprovethevalues,butnodataiscurrentlyavailable.ASTMA1085shallalsonotbespecifiedfordynamicloadingapplications.AvailabilityandminimumtonnageordersshallbeinvestigatedpriortospecifyingASTMA1085.

E. Plate Sizes

Platethicknessesoflessthan5/16inchesshallnotbeusedforbridgeapplications.

F. Fasteners

Allboltedconnectionsshallbefrictiontype(slip-critical).AssumeClassBfayingsurfaceswhereinorganiczincprimerisused.

General Guidelines for Steel Bolts

A. ASTMF3125GRA325&GRF1852

Highstrengthsteel,headedboltsforuseinstructuraljoints.Theseboltsmaybehot-dipgalvanizedbutshallnotbeusedinstructuresthatarepainted.Donotspecifyforanchorbolts.

B. A449

Highstrengthsteelboltsandstudsforgeneralapplicationsincludinganchorbolts.RecommendedforusewherestrengthsequivalenttoASTMF3125GR A325bolts(upto1”diameter)aredesiredbutcustomgeometryorlengthsarerequired.Theseboltsmaybehot-dipgalvanized.DonotusetheseasanchorboltsforseismicapplicationsduetolowCVNimpacttoughness.



C. F1554-Grade105

Higherstrengthanchorboltstobeusedforlargersizes(1½″to4″).Whenusedinseismicapplications,specifysupplementalCVNrequirementS5.Lowergradesmayalsobesuitableforsignstructurefoundations.Thisspecificationshallbeusedforseismicrestrainerrods,andmaybegalvanized.TheequivalentAASHTOM314shallnotbespecifiedasitdoesnotincludetheCVNsupplementalrequirements.

D. ASTMF3125GR A490&GRF2280

Highstrengthalloysteel,headedboltsforuseinstructuraljoints.Theseboltsshallnotbegalvanized,becauseofthehighsusceptibilitytohydrogenembrittlement.Inlieuofgalvanizing,theapplicationofanapprovedzincrichpaintmaybespecified.Donotspecifyforanchorbolts.

E. A354-GradeBD

Highstrengthalloysteelboltsandstuds.ThesearesuitableforanchorboltswherestrengthsequaltoA490boltsaredesired.Theseboltsshallnotbegalvanized.Ifusedinseismicapplications,specifyminimumCVNtoughnessof25feet-lbat40°F.

15.6.2 Girder BridgesA. Tub or Box Girders

Steelboxgirdersshallbetrapezoidaltubsections.Tubgirderswillbereferredtohereinasboxgirders,asinAASHTOLRFDArticle6.11.

Atoplateralsystemshallbeplacedinsidethegirderandshallbetreatedasanequivalentplatefordesign,closingtheopensectionandprovidingtorsionalstiffnessuntilthebridgedeckisfullycured.StabilityoftheshapeshallbeensuredforallstagesofconstructioninaccordancewithAASHTOLRFDArticle6.11.3.Boxgirderbridgeswithamultipleboxgirdercrosssectionshallhaveasinglebearingperbox.Forbridgesofasingleboxgirdercrosssection,twobearingsperboxshallbeused.Platediaphragmswithaccessholesshallbeusedinplaceofpiercrossframes.

Withtheexceptionofeffectsfrominclinedwebs,topflangesandwebsshallbedesignedasiftheywerepartofindividualI-girders.

Inordertomaximizewebspacingwhileminimizingbottomflangewidth,placewebsoutofplumbonaslopeof1in4.Whenrequiredtostiffenbottomflangesincompressionteesectionsshallbeusedforlongitudinalstiffeners.Channelbracingmaybeusedatcrossframelocationsfortransversestiffeners.Bottomflangestiffenersshallbeterminatedatfieldsplices.Otherwise,carefullygroundweldterminationsarerequiredintensionregionswithhighstressrange.Stiffenerplatesshallbeweldedacrossthebottomflangeatcrossframelocations,andshallnotbecombinedwithwebverticalstiffeners.



B. FractureCriticalSuperstructures

Non-redundant,fracturecriticalsingletubsuperstructures,andtwinI-girdersystems,mayonlybeconsideredifallowedbyRFPCriteria.UBITaccessorsomeformofpermanentfalsedeckingorotherinspectionaccessisrequiredforfracturecriticalinspections.ThemaximumroadwaywidthforeitherasingleboxortwinI-girdersuperstructureis27feet.Whereroadwaywidthexceeds27feet,additionalwebs/girdersshallbeused.Mainlinestructuresexceeding38feetinwidthshallusefourwebs/girdersminimum.

Increasedverticalclearancefrommainlinetrafficshallbeprovidedforeitherofthesebridgetypes.Theminimumis20feet.ThewebdepthsmaybereducedbelowAASHTOLRFDTable2.5.2.6.3-1minimumsprovidedliveloaddeflectioncriteriaaremet.However,webdepthlessthan5′-0″isnotpermitted.Thelimitstateloadmodifierrelatingtoredundancy,ηr=1.05,asspecifiedinAASHTOLRFDSection1.3.4,shallbeusedinthedesignofnon-redundantsteelstructures.Forloadratingnon-redundantbridges,asystemfactorof0.85isrequiredintheAASHTOManual for Bridge Evaluation(MBE)ontheaxialandflexuralcapacityofthegirders.ThegirderdesignshallsatisfyboththeAASHTOLRFDcodeandtheMBE.

TheAASHTOLRFDapproximateliveloaddistributionfactorsarenotapplicabletothesegirdertypes.Thelevelruleorthepreferredrefinedanalysisshallbeused.Wherehighlycurved,onlyarefinedanalysisshallbeused.

15.6.3 Design of I-GirdersA. LimitStatesforAASHTOLRFD

ThefatigueliveloadspecifiedinAASHTOLRFDArticle3.6.1.4shallbeusedforcheckinggirderdetailsinaccordancewitharticle6.6.Itisgenerallypossibletomeettheconstantamplitudefatiguelimit(CAFL)requirementfordetailswithgoodfatigueperformance.LimitingthecalculatedfatiguerangetotheCAFLensuresinfinitefatiguelife.WebsshallbecheckedforfatigueloadinginaccordancewithAASHTOLRFDArticle6.10.5.3,usingthecalculatedfatiguestressrangeforflexureorshear.Flangesandwebsshallmeetstrengthlimitstaterequirementsforbothconstructionandfinalphases.

Piercrossframesshallbedesignedforseismicloading,extremeeventloadcombination.BoltsshallbetreatedasbearingtypeconnectionswithAASHTOLRFDArticle6.5.4.2resistancefactors.Theresistancefactorforallothermembersis1.0atextremelimitstate.

B. CompositeSection

LiveloadplusimpactshallbeappliedtothetransformedcompositesectionusingEs/Ec,commonlydenotedn.Long-termloading(deadloadofbarriers,signs,luminaries,overlays,etc.)shallbeappliedtothetransformedcompositesectionusing3n.Positivemomentsareappliedtothesecompositesectionsaccordingly;bothforserviceandstrengthlimitstates.Thebridgedeckmaybeconsideredeffectiveinnegativemomentregionsprovidedtensilestressesinthedeckarebelowthemodulusofrupture.ThisisgenerallypossibleforServiceIloadcombinationandfatigueanalysis.Forstrengthlimitstateloadings,thecompositesectionincludeslongitudinalreinforcingwhilethebridgedeckisignored.



C. Flanges

Themaximumflangethicknessis3-inches.Allplatesforflangematerialshallbepurchasedsuchthattheratioofreductionofthicknessfromaslabtoplateshallbeatleast3.0:1.

Asanalternative,platesforflangematerialgreaterthan2″thicknotmeetingthe3.0:1ratioofreductionmaybesuppliedbasedonacceptableultrasonictesting(UT)inspectioninaccordancewithASTMA578.UTscanningandacceptanceshallbeasfollows:• TheentireplateshallbescannedinaccordancewithASTMA578andshallmeetAcceptanceStandardC,and

• Platematerialwithin12-inchesofflangecompletejointpenetrationspliceweldsshallbescannedinaccordancewithASTMA578SupplementaryS1andshallmeetAcceptanceStandardC

D. Webs

Ifdifferentwebthicknessisneeded,thetransitionshallbeataweldedsplice.Horizontalwebsplicesshallnotbeusedunlesswebheightexceeds12′-6″.Allweldedwebsplicesonexteriorfacesofexteriorgirdersandintensionzoneselsewhereshallbegroundsmooth.Websplicesofinteriorgirdersneednotbegroundincompressionzones.

E. TransverseStiffeners

Transversestiffenersshallbeusedinpairsatcrossframelocationsoninteriorgirdersandontheinsideofwebsofexteriorgirders.Theyshallbeweldedtothetopflange,bottomflangeandwebattheselocations.ThisdetailisconsideredfatiguecategoryC’forlongitudinalflangestress.Stiffenersusedbetweencrossframesshallbelocatedononesideoftheweb,weldedtothecompressionflange,andcutshortofthetensionflange.Stiffenerslocatedbetweencrossframesinregionsofstressreversalshallbeweldedtoonesideofthewebandcutshortofbothflanges.Alternatively,theymaybeweldedtobothflangesiffatigueCategoryC’ischecked.

Stiffenedwebsrequireendpanelstoanchorthefirsttensionfield.Thejackingstiffenertobearingstiffenersspaceshallnotbeusedastheanchorpanel.Thefirsttransversestiffenershallbeplacedatnogreaterspacingthan1.5timesthewebdepthfromthebearingorjackingstiffener.

F. LongitudinalStiffeners

Longitudinalstiffenersmaybeusedinlongspanswherewebdepthsexceed10feetinaccordancewithAASHTOLRFDArticle6.10.11.3.Weldterminationsforlongitudinalstiffenersarefatiguepronedetailsandshallbedetailedaccordingly.Longitudinalstiffenerplatesshallbecontinuous,splicesbeingmadewithfullpenetrationweldsbeforebeingattachedtowebs.Transversestiffenersshallbepiecedtoallowpassageoflongitudinalstiffeners.



G. BearingStiffeners

Bearingstiffenersshallbeverticalundertotaldeadload.

Piercrossframesmaytransferlargeseismiclateralloadsthroughtopandbottomconnections.Weldsizeshallbedesignedtoensureadequateloadpathfromdeckandcrossframesintobearings.

H. CrossFrames

Crossframesandconnectionsshallbedetailedforrepetitivefabrication,adjustmentinthefield,andopennessforinspectionandpainting.Crossframesconsistingofback-to-backanglesseparatedbygussetplatesarenotpermitted.CrossframesaregenerallypatternedasK-framesorasX-frames.Oversizeholeswillnotbeallowedincrossframeconnectionsifgirdersarecurved.

Intermediatecrossframesforstraightgirderswithlittleornoskewshallbedesignedassecondarymembers.Membersizesshallbeselectedtomeetminimumslendernessrequirementsanddesignconnectionsonlyforanticipatedloads,notfor75percentstrengthofmember.

Crossframesshallbeinstalledparalleltopiersforskewanglesof0degreesto20degrees.Forgreaterskewangles,otherarrangementsmaybeused.Crossframesforcurvedgirderbridgesaremainloadcarryingmembersandtensioncomponentsshallbesodesignatedintheplans.Webstiffenersatcrossframesshallbeweldedtotopandbottomflanges.

I. BottomLaterals

Inaccordancewith6.1.2,bottomlateralsystemsshallbeavoidedexceptwhenrequiredforstabilityincurvedbridgesandshallbeusedonlywhentemporarybracingisnotpractical.

Wherelateralgussetplatesarefilletweldedtogirderwebs,thefatiguestressrangeinthegirderislimitedtoCategoryEwithouttransitionradiusorCategoryDwithcarefullymadetransitionradius.Thegussetplatesshallbeboltedtothegirderwebinregionsofhightensionstressrange.

J. BoltedFieldSpliceforGirders

Fieldsplicesshallbebolted.Boltedwebsplicesshallnotinvolvethinfillmaterial.Thicknesstransitionsforwebs,ifneeded,shallbedonewithweldedshopsplices.

FillersusedinboltedsplicesshallbedevelopedasspecifiedinAASHTOLRFDArticle6.13.6.1.5.SpliceboltsshallbecheckedforStrengthloadcombinationsandslipatServiceIIloadcombination.Whenfayingsurfacesareblastedandprimedwithinorganiczincpaint,aClassBsurfaceconditionshallbeassumed.

K. Camber

Cambershallincludeeffectsofprofilegrade,superelevation,anticipateddeadloaddeflections,andbridgedeckshrinkage(ifmeasurable).Permanentgirderdeflectionsshallbeshownintheplansintheformofcamberdiagramsandtables.Deadloaddeflectionsareduetosteelself-weight,bridgedeckdeadload,andsuperimposeddeadloadssuchasoverlay,sidewalks,andbarriers.Aconstantdistancefromtopofwebtotopofbridgedeckshallbeassumedfordesign,



howeverformsandhaunchheightshallbeadjustedtomeetbridgedeckthicknessandprofileasspecifiedinStandard Specifications Section6-03.3(39).

Twocambercurvesarerequired,onefortotaldeadloadplusbridgedeckformworkandoneforsteelframingself-weight.Thedifferencebetweenthesecurvesisusedtosetbridgedeckforms.

Girderself-weightshallincludethebasicsectionplusstiffeners,crossframes,welds,shearstuds,etc.Theseitemsmaybeaccountedforbyaddinganappropriatepercentageofbasicsectionweight.Totaldeadloadcambershallconsistofdeflectiondueto:

1. Steelweight,appliedtosteelsection.Include10psfbridgedeckformworkallowanceinthetotaldeadloadcamber,butnotinthesteelweightcamber.Theeffectofremovingformworkissmallinrelationtofirstplacement,duetocompositeactionbetweengirdersandbridgedeck.Itisn’tnecessarytoaccountfortheremoval.

2. Bridgedeckweight,appliedtosteelsection.

3. Trafficbarriers,sidewalks,andoverlays,appliedtolong-termcompositesectionusing3n.Donotincludeweightoffutureoverlaysinthecambercalculations.

4. Bridgedeckshrinkage(if≥¾″).

Trafficbarriers,sidewalks,overlays,andotheritemsconstructedafterthebridgedeckplacementshallbeanalyzedasifappliedtothelong-termcompositesectionfulllengthofthebridge.Themodulusofelasticityofthebridgedeckconcreteshallbereducedtoonethirdofitsshorttermvalue.

Forbridgedeckshrinkagecalculation,applyashrinkagestrainof0.0002tothelong-termcompositesectionusing3n.

Inadditiontogirderdeflections,girderrotationsatbearingstiffenersshallbeshown.CambertoleranceisgovernedbytheBridge Welding CodeAWSD1.5,Chapter3.5.Anoteofclarificationshallbeaddedtotheplancamberdiagram:“Forthepurposeofmeasuringcambertoleranceduringshopassembly,assumetopflangesareembeddedinconcretewithoutadesignedhaunch.”Thisallowsahighorlowdeviationfromthetheoreticalcurve,otherwisenonegativecambertoleranceisallowed.

Ascreedadjustmentdiagramshallbeincludedwiththecamberdiagram.Thisdiagram,withdimensiontable,shallbetheremainingcalculateddeflectionjustpriortobridgedeckplacement,takingintoaccounttheestimatedweightofdeckformworkanddeckreinforcing.Theweightofbridgedeckformworkmaybetakenequalto10psf,ortheassumedformworkweightusedtocalculatetotalcamber.Theweightofreinforcingmaybetakenasthespanaveragedistributeduniformly.Thescreedadjustmentshouldequal:(TotalCamber–SteelCamber)-(deflectionduetoforms+rebar).Thescreedadjustmentshallbeshownateachgirderline.Thiswillindicatehowmuchdeflectionandtwistingisanticipatedduringbridgedeckplacement,primarilyduetospancurvatureand/orskew.Theseadjustmentsshallbeappliedtotheoreticalprofilegrades,regardlessofactualsteelframingelevations.Theadjustmentsshallbedesignated“C”.Thediagramshallbe




designatedas“ScreedSettingAdjustmentDiagram.”Thetableofdimensionsshallbekeptseparatefromthegirdercamber,butatconsistentlocationsalonggirders.Thatis,at1/10thpointsorpanelpoints.Acrosssectionviewshallbeincludedwithcurvedspanbridges,showingeffectsoftwisting.

Forthepurposeofsettingbridgedecksoffitelevations,acorrectionshallbemadetotheplanhaunchdimensionbasedonthedifferencebetweentheoreticalflangelocationsandactualprofiledelevations.Thepresenceofbridgedeckformworkshallbenotedatthetimeofthesurvey.Thepresenceoffalsedeckingneednotbeaccountedforindesignorthesurvey.

L. BridgeDeckPlacementSequence

Thebridgedeckshallbeplacedinaprescribedsequenceallowingtheconcreteineachsegmenttoshrinkwithminorinfluenceonothersegments.Negativemomentregions(segmentsoverinteriorpiers)shallbeplacedafterpositivemomentregionshavehadtimetocure.Successivesegmentsshallnotbeplaceduntilprevioussegmentsattainsufficientstrength.Thedesignershallcheckbridgedecktensilestressesimposedonadjoiningspansegments.

M. Bridge Bearings for Steel Girders

Makebearingselectionconsistentwithrequiredmotionsandcapacities.

N. Surface Roughness and Hardness

Thestandardmeasureofsurfaceroughnessisthemicroinchvalue.SurfaceroughnessshallbeshownontheplansforallsurfacesforwhichmachiningisrequiredunlesscoveredbytheStandard SpecificationsorSpecialProvisions.Surfacehardnessofthermalcutgirderflangesisalsocontrolled.

O. Welding

Theminimumfilletweldsizeshallbeasshowninthefollowingtable.Weldsizeisdeterminedbythethickerofthetwopartsjoinedunlessalargersizeisrequiredbycalculatedstress.Theweldsizeneednotexceedthethicknessofthethinnerpartjoined.

Base Metal Thickness of Thicker Part Joined Minimum Size of Fillet Weld

To ¾″ inclusive ¼″Over ¾″ 5/16″

P. ShopAssembly

Forstraightgirders,aprogressivelongitudinalshopassemblyshallbeperformedtoensureproperfitofsubsections,fieldsplices,andcrossframeconnections,etc.,inthefield.Progressivetransverseassembly,incombinationwithprogressivelongitudinalassemblyshallbeperformedforbridgeswithhorizontalcurvatureorskewsgreaterthan20-degrees.Fortransverseassembly,specifyallcrossframeandpierdiaphragmconnectionstobecompletedwhileassembled.

Duringshopassembly,girdersegmentsshallbeblockedorsupportedintheno-loadcondition(nogravityeffects).ForcurvedI-girders,crossframesshallbefabricatedtofittheno-loadcondition.Designofcrossframesandpierdiaphragms




shalltakeintoaccounttwistandrotationsofwebsduringconstruction.Thissituationshouldbecarefullystudiedbyfiniteelementanalysistodetermineamountandtypeofmovementanticipatedduringconstruction.Unlikecurvedgirdersrotatingawayfromplumbatmidspan,girderwebsforskewedconstructionshallbekeptplumbatpiers.

Forbridgeswithskewsgreaterthan20-degrees,thefitofgirdersegments,crossframes,andpierdiaphragmsshallbecarefullyanalyzedduringdesigntoselecttheproperfitcondition,whichshallbeeithertheno-loadconditionofthesteeldeadloadcondition.Thedetailing,fabrication,andshopassemblyshallbespecifiedtomatchtheconditionusedintheanalysisanddesign.

15.6.4 Plan DetailsA. General

Detailingpracticeshallfollowindustrystandards.DesignationsforstructuralsteelcanbefoundinAISCDetailing for Steel Construction.DetailingshallalsoconformtonationalunifiedguidelinespublishedbyAASHTO/NSBASteel Bridge Collaboration.

Connectionsinthefieldshallbebolted.Crossframemembersmaybeshopboltedorweldedassembliesandshallbeshippedtothefieldinoneunit.Connectionsofboltedcrossframeassembliesshallbefullytensionedpriortoshipping.Crossframeassembliesshallbefieldboltedtogirdersduringerection.

B. FramingPlan

TheFramingPlanshallshowtiesbetweenthesurveyline,girderlines,backsofpavementseats,andcenterlinesofpiers.Locatepanelpoints(crossframelocations).Providegeometry,bearinglines,andtransverseintermediatestiffenerlocations.Showfieldsplicelocations.Mapoutdifferentlateralconnectiondetails.

C. Girder Elevation

TheGirderElevationisusedtodefineflanges,webs,andtheirsplicelocations.Showshearconnectorspacing,location,andnumberacrosstheflange.Showshearconnectorlocationsonflangespliceplatesorspecificallycalloutwhennoconnectorsarerequiredonspliceplates.Locatetransversestiffenersandshowwheretheyarecutshortoftensionflanges.ShowthetensionregionsofthegirderswithaVforthepurposeoforderingplatematerial,inspectionmethods(NDE),andBridge Welding Codeacceptancecriteria.Identifytensionweldedbuttsplicesforwhichradiographicexamination(RT)isrequired.Permissibleweldedwebsplicesshallbeshown.Iftherearefracturecriticalcomponents,theyshallbeclearlyidentifiedasFCM.

D. TypicalGirderDetails

Specificsheetsshallbedevotedtoshowingtypicaldetailstobeusedthroughoutthegirders.Suchdetailsincludethewelddetails,variousstiffenerplatesandweldconnections,locationsofoptionalwebsplices,anddripplatedetails.Fieldsplicesforflangesshallaccommodateweblocationtoleranceof±¼″inaccordancewiththeAWSBridge Welding Code3.5.1.5.Allowaminimumof¼″foroutofpositionwebplus⅜″forfilletweld,oratotalof⅝″minimumclearbetweentheoretical



faceofwebandedgeofspliceplate.Thebottomflangespliceplateshallbesplittoallowmoisturetodrain(use4equalbottomflangespliceplates).Thefillplatedoesnotneedtobesplit.

Verticalstiffenersusedtoconnectcrossframesshallbeweldedtotopandbottomflangestoreduceout-of-planebendingoftheweb.Allstiffenersshallbecoped,clipped(orcutshortinthecaseoftransversestiffenerswithoutcrossframes)adistancebetween4twand6twtoprovidewebflexibility,inaccordancewithAASHTOLRFDArticle6.10.11.1.1.

F. CrossFrameDetails

Showmembersizes,geometrics(worklinesandworkpoints),andconnectiondetails.Doubleanglesshallnotbeusedforcrossframes.Crossframesshallbecompletesubassembliesforfieldinstallation.

Internalcrossframesandtoplateralsystemsforboxgirdersareshopwelded,primarily.Allconnectiontypesshallbecloselyexaminedfordetailconflictandweldaccess.Clearancebetweenbridgedeckformingandtoplateralmembersshallbeconsidered.

G. CamberDiagramandBearingStiffenerRotation

Cambercurvesshallbedetailedtoprovidedimensionsattenthpoints.Dimensionsmayalsobegivenatcrossframelocations.Inordertoplacebearingstiffenersintheverticalpositionafterbridgedeckplacement,showexpectedgirderrotationsatpiers.

Showdeflectioncamberonly.GeometriccamberforprofilegradeandsuperelevationwillbecalculatedbytheshopdetailerfromhighwayalignmentshownontheLayoutsheets.

Aseparatediagramandtable,withbridgecrosssection,shallbeincludedtoshowhowelevationsatedgesofdeckcanbedeterminedjustbeforeconcreteplacement.Thiswillgiveadjustmentstoaddtoprofilegrades,basedonremainingdeadloaddeflections,withdeckformworkandreinforcingbeingpresent.

H. Bridge Deck

NewbridgedecksforsteelI-girdersorboxgirdersshalluseDeckProtectionSystem1.

Thebridgedeckshallbedetailedinsectionandplanviews.Forcontinuousspans,showasectionshowingnegativemomentlongitudinalreinforcing.Theplanviewsshalldetailtypicalreinforcingandcutofflocationsfornegativemomentsteel.Negativemomentsteelshallnotbeterminatedatonelocation.

Thepaddimensionisassumedtobeconstantthroughoutthespanlength.Ideally,thegirderiscamberedtocompensatefordeadloadsandverticalcurves.However,fabricationanderectiontolerancesresultinconsiderabledeviationfromtheoreticalelevations.Thepaddimensionisthereforeconsideredonlyanominalvalueandisadjustedasneededalongthespanoncethesteelhasbeenerectedandprofiled.Thescreedfortheslabistobesettoproducecorrectroadwayprofile.TheplansshallreferencethisprocedurecontainedinStandard Specifications Section6-03.3(39).Thepaddimensionistobenotedasnominal.



I. HandrailDetails,InspectionLighting,andAccess

WhenrequiredbytheRFPCriteria,includehandrailswithtypicalgirderdetails.Locationsmaybeadjustedtoavoidconflictswithotherdetailssuchaslargegussetplates.Boxgirdersrequirespecialconsiderationforinspectionaccess.Accessholesorhatchesshallbedetailedtoexcludebirdsandthepublic.Theyshallbepositionedwhereladderscanbeusedtogainaccess.Locatehatchesingirderwebsatabutments.Provideforroundtripaccessandpenetrationsatallintermediatediaphragms.Accessforremovingbridgedeckformworkshallbeprovided.Boxgirdersshallhaveelectrical,inspectionlighting,andventilationdetailsfortheaidofinspectionandmaintenance.RefertotheDesign ManualChapter1040forbridgeinspectionlightingrequirements.

Tofacilitateinspection,interiorpaintshallbeFederalStandard595colornumber17925(white).One-wayinspectionofallinteriorspacesshallbemadepossiblebyroundtripinadjoininggirders.Thisrequiressomeformofwalkwaybetweenboxesandhatchoperationfrombothsides.Iflocksareneeded,theymustbekeyedtoonemaster.Airventsshallbeplacedalonggirderwebstoallowfreshairtocirculate.

J. Box Girder Details

Provideatoplateralsystemineachbox,fulllengthofagirder.

Thetoplateralsshallbebolteddirectlytothetopflangeorintermediateboltedgussetplate(inwhichcase,thelateralmembersmaybeweldedtothegussetplate).Inordertomaximizetheclearancefordeckforms,alllateralconnectionsshallprogressdownfromthebottomsurfaceofthetopflange.Thehaunchdistancebetweentopofwebanddecksoffitshallbe6″orgreatertoallowdeckformingtocleartoplateralmembers.

Tofacilitatecontinuousweldingofthebottomflangetowebs,thestiffenersshallbeheldbackandattachedtothebottomflangebyamemberbroughtinafterthebottomlongitudinalweldsarecomplete.

Theoffsetbetweencenterofwebandedgeofbottomflangeshallbe2″

Useteeshapes,eithersinglyorinpairs,forstiffeningwidebottomflanges.

Boxgirderinsideclearheightshallbe5feetormoretoprovidereasonableinspectionaccess.Lessthan5feetinsideclearheightisnotbepermitted.

Drainholesshallbeinstalledatalllowpoints.

Geometricsforboxesshallbereferencedtoasingleworkline,unlessboxwidthtapers.Theboxcrosssectionremainstiedtoacenterlineintersectingthisworklineandnormaltothebridgedeck.Thesectionrotateswithsuperelevationtransitionratherthanwarping.



15.7 Substructure Design15.7.1 General Substructure Considerations

A. Foundation Seals

Thebottomofseal,ifused,shallbenohigherthanthescourdepthelevation.

B. Scour

Thedesignfloodlocalscourdepth(l00yearevent)shallbeincludedintheStrengthIlimitstateanalysis,andthecheckfloodlocalscourdepth(500yearevent)shallbeincludedintheExtremeEventIIlimitstateanalysis.Whenincludingtheeffectsofscour,thedesignshallconsiderthelossofoverburdenandfoundationsideresistance.

Wherelateralstreammigrationisapossibility,thedesignshallincludeareliability-basedestimateoftheeffectsonthestructure.

C. CombinationofExtremeEventEffects

1. Downdrag

SeismicsoilliquefactioninduceddowndragforcesshallbeincludedintheExtremeEventIlimitstate.Downdragloadsmaybedecoupledfromtheinertialandoverstrengthloadeffects.

2. LateralGroundDisplacement

Wherelateralgrounddisplacement(e.g.lateralspreadingandlateralflow)isexpected,thegrounddisplacementmaybedecoupledfromtheinertialandoverstrengthloadeffects.SeeWSDOTGeotechnical Design ManualSections6.4.2.8and6.5.4.2foradditionalguidanceoncombiningloadswhenlateralgrounddisplacementoccurs.

3. Scour

Theeffectsoflocalscourshallbecombinedwithearthquakeloading.AttheExtremeEventIlimitstate,thedesignshallconsiderascourdepthequalto25percentofthedesignfloodscourdepth.

15.7.2 Foundation Modeling for Seismic LoadsA. General

BridgemodelingforseismiceventsshallbeinaccordancewithrequirementsoftheAASHTOSEISMICSection5.

Ifliquefactionisadesigncondition,thebridgeshallbeanalyzedusingboththestaticandliquefiedsoilconditionsinaccordancewithAASHTOSEISMICSection6.8.

TheLPileprogrammaybeusedforpileandshaftsupportedfoundations.However,theLiquefactionoptionandLiquefiedSandsoiltypeintheLPILEprogramshallnotbeused.




B. BridgeModelSectionProperties

Ingeneral,grosssectionpropertiesmaybeassumedforallmembers,exceptconcretecolumnsandotherductilereinforcedconcretemembers.Seismicresponseanalysisfordeepfoundationsshallbebasedonabracketedapproachusingastiffsubstructureresponseandasoftsubstructureresponse.

1. CrackedPropertiesforColumns

EffectivesectionpropertiesshallbeinaccordancewiththeAASHTOSEISMICSection5.6.

2. ShaftProperties

Theshaftconcretestrengthandconstructionmethodsleadtosignificantvariationinshaftstiffnessdescribedasfollows:

Forastiffsubstructureresponse:

1. Use1.5ƒ′ctocalculatethemodulusofelasticity.

2. UseIgbasedontheactualshaftdiameter.

3. Whenpermanentcasingisused,increaseshaftIgusingthetransformedareaofthecasing.

Forasoftsubstructureresponse:

1. Useƒ′ctocalculatethemodulusofelasticity.

2. UseIgbasedontheactualshaftdiameter.Alternatively,Iemaybeusedwhenitisreflectiveoftheactualloadeffectsintheshaft.

3. Whenpermanentcasingisused,increaseshaftIgusingthetransformedareaofthecasing.

3. Cast-in-PlacePileProperties

Forastiffsubstructureresponse:


2. UsethepileIgplusthetransformedcasingmomentofinertia.

Forasoftsubstructureresponse:


2. UsepileIg,neglectingcasingproperties.

C. SpreadFootingModelingMethods

ThemethodforcalculatingfootingspringsisgiveninSection7.2.7.

D. DeepFoundationModelingMethods

ThemethodusedtomodeldeepfoundationsshallconformtoAASHTOSEISMICSection5.3.

1. GroupEffects

ThereductionfactorsforlateralresistanceduetotheinteractionofdeepfoundationmembersisprovidedinAASHTOSEISMICSection8.12.2.5.



2. ShaftCapsandPileFootings

Inareaspronetoscourorlateralspreading,thepassiveresistanceofcapsandpile-supportedfootingsshallbeneglected.

E. DesignofDeepFoundationsforLateralForces

1. DeterminationofTipElevations

Aparametricstudyoranalysisshallbeperformedtoevaluatethesensitivityofthedepthoftheshaftorpiletothegroundleveldisplacementofthestructureinordertodeterminethedepthrequiredforstable,proportionatelateralresponseofthestructure.

2. Design for Lateral Loads

Thestructuraldesignofshaftsandpilesshallconsiderthefollowingconditionsattheapplicablelimitstate:

a. Staticsoilpropertieswithbothstiffandsoftshaftorpileproperties.

b. Dynamicordegradedsoilpropertieswithbothstiffandsoftshaftorpileproperties.

c. Liquefiedsoilpropertieswithbothstiffandsoftshaftorpileproperties.Whenlateralspreadingispossible,additionalloadingconditionswillneedtobeanalyzed.

d. Scourconditionwithstiffandsoftshaftorpileproperties.

15.7.3 Column DesignA. Shear Design

AtStrengthlimitstates,sheardesignshallfollowthe“SimplifiedProcedureforNonprestressedSections”inAASHTOLRFD Section5.8.3.4.1.

B. ColumnSilos

Duetotheconstructionandinspectioncomplicationsofcolumnsilos,theDesign-BuildershallattempttomeetbalancedstiffnessandframegeometryrequirementsbytheothermethodssuggestedinSection4.1.4oftheAASHTOSEISMIC priortouseofcolumnsilos.ColumnsilosshallmeettherequirementsofSection7.3.8.

C. LongitudinalReinforcement

Themaximumreinforcementratioshallbe0.04inSDCsA,B,CandD.Theminimumreinforcementratioshallbe0.007forSDCA,B,andCandshallbe0.01forSDCD.

ForbridgesinSDCA,ifoversizedcolumnsareusedforarchitecturalreasons,theminimumreinforcementratioofthegrosssectionmaybereducedto0.005,providedallloadscanbecarriedonareducedsectionwithsimilarshapeandthereinforcementratioofthereducedsectionisequaltoorgreaterthan0.01and0.133ƒ′c/ƒy.Thecolumndimensionsaretobereducedbythesameratiotoobtainthesimilarshape.

Thereinforcementshallbeevenlydistributedandsymmetricwithinthecolumn.



D. LongitudinalReinforcementSplices

Nosplicesareallowedwhentherequiredlengthoflongitudinalreinforcementislessthantheconventionalmilllengthof60-feet.Splicingoflongitudinalreinforcementshallbeoutsidetheplastichingeregions.ButinSDCA,splicesneedonlybelocatedaminimumof1.5timesthecolumndiameterfromthetopandbottomofthecolumn.

ForbridgesinSDCAandSDCB,nolapsplicesshallbeusedfor#14or#18bars(suchsplicesshallbemechanicalsplicesconformingtoStandard Specifications Section6-02.3(24)C).Eitherlapormechanicalsplicesmaybeusedfor#11barsandsmaller.LapsplicesshallbedetailedasClassBsplices.Thespacingoftransversereinforcementoverthelengthofalapspliceshallnotexceed4-inchesorone-quarteroftheminimummemberdimension.

ForbridgesinSDCCandSDCD,barsshallbesplicedusingmechanicalsplicesconformingtoStandard SpecificationsSection6-02.3(24)F.Splicesshallbestaggered.Thedistancebetweensplicesofadjacentbarsshallbegreaterthanthemaximumof20-bardiametersor24-inches.

E. LongitudinalReinforcementDevelopment

1. Crossbeams

DevelopmentoflongitudinalreinforcementshallbeinaccordancewithAASHTOSEISMICSection8.8.4.Columnlongitudinalreinforcementshallbeextendedintocrossbeamsascloseaspracticablypossibletotheoppositefaceofthecrossbeam.

2. Footings

Longitudinalreinforcementatthebottomofacolumnshouldextendintothefootingandrestonthebottommatoffootingreinforcementwithstandard90degreehooks.Inaddition,developmentoflongitudinalreinforcementshallbeinaccordancewithAASHTOSEISMICSection8.8.4andAASHTOLRFDSection5.11.2.1.

3. Drilled Shafts

EmbedmentshallbespecifiedusingTRACReportWA-RD417.1titled“NoncontactLapSplicesinBridgeColumn-ShaftConnections”.TherequirementsoftheAASHTOSEISMICSection8.8.10fordevelopmentlengthofcolumnbarsextendedintooversizedpileshaftsforSDCCandDshallnotbeused.

ThemodificationfactorinAASHTOLRFDSection5.11.2.1.3thatallowsldtobedecreasedbytheratioof(As required)/(As provided),shallnotbeused.

F. TransverseReinforcement

1. General

Alltransversereinforcementincolumnsshallbedeformed.ColumnsinSDCAandBmayusespirals,circularhoops,orrectangularhoopsandcrossties.ColumnsinSDCCandDshallusecircularhoopreinforcement.However,rectangularhoopswithtiesmaybeusedwhenlarge,oddshapedcolumnsectionsarerequired.



2. SpiralSplicesandHoops

Weldedlapsshallbeusedforsplicingandterminatingspirals.Spiralsorbutt-weldedhoopsarerequiredwithinplastichingeregions.Splicesshallbestaggered.Also,whereinterlockinghoopsareusedinrectangularornon-circularcolumns,thesplicesshallbelocatedinthecolumninterior.Circularhoopsforcolumnsshallbeshopfabricatedusingamanualdirectbuttweldorresistancebuttweld.Fieldweldedsplicesandterminationweldsofspiralsofanysizebararenotpermittedintheplastichingeregion,includingazoneextending2’-0”intotheconnectedmember.

G. ReducedColumnSection

ColumnswithoverstrengthforcereducingdetailsshallbedesignedinaccordancewithSection7.3.7.

15.7.4 CrossbeamTwo-stageintegralnon-prestressedcrossbeamsshallbedesignedinaccordancewithSection7.4.1.

15.7.5 Abutment Design and DetailsA. General

1. Bent-TypeAbutments

Abutmentsthatincludeabentcapsupportedoncolumnsorextendedpilesorshaftsshallnotbeused.

2. AbutmentsonStructuralEarth(SE)WallsandGeosyntheticWalls

Bridgeabutmentsmaybesupportedonstructuralearthwallsandgeosyntheticwalls.AbutmentssupportedonthesewallsshallbedesignedinaccordancewiththerequirementsofthisRFPandthefollowingdocuments(listedinorderofimportance):• WSDOTGeotechnical Design ManualSection15.5.3.5• AASHTOLRFD• Design and Construction of Mechanically Stabilized Earth Walls

and Reinforced Soil Slopes,VolumeIandII,FHWA-NHI-10-024,FHWA-NHI-10-025

Wallsdirectlysupportingbridgeabutmentspreadfootingsshallbe30feetorlessintotalheight,measuredfromthetopofthefascialevelingpadtothebottomofthebridgeabutmentfooting.

B. EmbankmentandBackfill

1. General Clearances

TheminimumclearancesfortheembankmentatthefrontfaceofabutmentsshallbeasindicatedonStandardPlansA-50.10.00throughA-50.40.00.

Theminimumclearancebetweenthebottomofthesuperstructureandtheembankmentbelowshallbe3’-0”forgirderbridgesand5’-0”fornon-girder,slab,andboxgirderbridges.


http://www.fhwa.dot.gov/engineering/geotech/pubs/nhi10024/nhi10024.pdf

http://www.fhwa.dot.gov/engineering/geotech/pubs/nhi10025/nhi10025.pdf




2. AbutmentsonSEWallsandGeosyntheticWalls

ClearancesaroundbridgeabutmentsshallbeprovidedasshowninFigure7.5.2-1.Concreteslopeprotectionshallbeprovided.

3. DrainageandBackfill

3″diameterweepholesshallbeprovidedinallbridgeabutmentwalls.Theseshallbelocated6″abovethefinishgroundlineat12′oncenter.Incaseswheretheverticaldistancebetweenthetopofthefootingandthefinishgroundlineisgreaterthan10′,additionalweepholesshallbeprovided6″abovethetopofthefooting.

Gravelbackfillforwallsshallbeprovidedbehindallbridgeabutments.A3′widthofgravelbackfillshallbeprovidedbehindthecantileverwingwalls.Anunderdrainpipeandgravelbackfillfordrainshallbeprovidedbehindallbridgeabutmentsexceptabutmentsonfillswithastemwallheightof5′orless.

C. AbutmentLoading

1. Earthquake Load

EQ

Forbearingpressureandabutmentstabilitychecks,theseismicinertialforceoftheabutment,PIR,shallbecombinedwiththeseismiclateralearthpressureforce,PAE,asdescribedinAASHTOLRFDSection11.6.5.1.Forstructuraldesignoftheabutment,theseismicinertialforce,PIR,maybetakenas0.0.

Forconventionalfootingsupportedabutments,theseismichorizontalaccelerationcoefficient,kh,shallbetakenasonehalfoftheseismichorizontalaccelerationcoefficientassumingzerodisplacement,kh0.TheseismicactiveearthpressureshallbedeterminedusingtheMononobe-Okabemethod,asdescribedinAASHTOLRFDAppendixA11.

Forpile-orshaft-supportedabutmentsorotherabutmentsthatarenotfreetotranslate1.0inchto2.0inchduringaseismicevent,useaseismichorizontalaccelerationcoefficient,kh,of1.5timesthesite-adjustedpeakgroundacceleration.

Theseismicverticalaccelerationcoefficient,kv,shallbetakenas0.0forabutmentdesign.

2. Bearing Forces

TU

Forstrengthdesign,thebearingshearforcesshallbebasedon½oftheannualtemperaturerange.

D. AbutmentDetails

1. Bearing Seats

Thebearingseatsshallhaveaminimumedgedimensionof3″fromthebearingsshallandsatisfytherequirementsofAASHTOLRFDSection4.7.4.4.OnLabutments,thebearingseatshallbeslopedawayfromthebearingstopreventpondingatthebearings.



2. TransverseGirderStops

Allsuperstructuresshallberestrainedagainstlateraldisplacementattheabutmentsandintermediateexpansionpiers.AllprestressedgirderbridgesinWesternWashington(withinandwestoftheCascademountainrange)shallhavegirderstopsbetweenallgirdersatabutmentsandintermediateexpansionpiers.GirderstopsshallbefullwidthbetweengirderflangesexcepttoaccommodatebearingreplacementrequirementsasspecifiedinChapter9. Girderstopsaredesignedusingashearstrengthresistancefactorshallbeϕs = 0.9.

3. AbutmentWalls

Whenconstructionjointsarelocatedinthemiddleoftheabutmentwall,apourstriporanarchitecturalrevealshouldbeusedforacleanappearance.AASHTOLRFDSection5.10.8shallbefollowedfortemperatureandshrinkagereinforcementrequirementsnearconcretesurfacesexposedtodailytemperaturechangesandinstructuralmassconcrete.Theminimumcrosstiereinforcementinabutmentwallsshallbe#4tiebarswith135°hooks,spacedatapproximately2′-0″center-to-centerverticallyandhorizontally.

15.7.6 Abutment Wing Walls and Curtain WallsWallfootingthicknessshallnotbelessthan1’-6”

15.7.7 Footing DesignA. General Footing Criteria

See Figure7.7.1-1forfootingcoverrequirements.FootingssupportedonSEwallsorgeosyntheticwallsshallhaveaminimumof6″ofcover.

B. SpreadFootingDesign

1. Foundation Design

a. Bearing Stress

ThemaximumeffectivewidthforcalculatinguniformbearingstressislimitedtoC+2DasshowninFigure7.7.4-3.

2. Structural Design

a. Footing Thickness and Shear

Theminimumfootingthicknessshallbe1′-0″.Theminimumplandimensionshallbe4′-0″.

b. VerticalReinforcement

Verticalreinforcementshallbedevelopedintothefootingtoadequatelytransferloadstothefooting.Verticalrebarshallbebent90°andextendtothetopofthebottommatoffootingreinforcement.Barsintensionshallbedevelopedusing1.25Ld.Barsincompressionshalldevelopalengthof1.25 Ld,priortothebend.Wherebarsarenotfullystressed,lengthsmaybereducedinproportion,butshallnotbelessthan¾Ld.



c. BottomReinforcement

Reinforcementshallnotbelessthan#6barsat12″centerstoaccountforunevensoilconditionsandshrinkagestresses.

d. TopReinforcement

Topreinforcementforfootingsdesignedfortwo-wayactionshallnotbelessthan#6barsat12″centers,ineachdirectionwhiletopreinforcementforbearingwalldesignedforone-wayactionshallnotbelessthan#5barsat12″centersineachdirection.

C. Pile-SupportedFootingDesign

Theminimumfootingthicknessshallbe2′-0″.Theminimumplandimensionshallbe4′-0.

1. PileEmbedment,Clearance,andRebarMatLocation

Cast-in-placeconcretepileswithreinforcingextendingintofootingsareembeddedaminimumof6″.Theclearanceforthebottommatoffootingreinforcementshallbe1½″betweenthereinforcingandthetopofthepileforCIPpilefootings.SeeFigure7.7.5-2fortheminimumpileclearancetotheedgeoffooting.

2. Concrete Design

Indeterminingtheproportionofpileloadtobeusedforcalculationofshearstressonthefooting,anypilewithitscenter6″ormoreoutsidethecriticalsectionshallbetakenasfullyactingonthatsection.Anypilewithitscenter6″ormoreinsidethecriticalsectionshallbetakenasnotactingforthatsection.Forlocationsinbetween,thepileloadactingshallbeproportionedbetweenthesetwoextremes.

15.7.8 ShaftsA. Axial Resistance

Thebridgeplansshallincludetheendbearingandsidefrictionnominalshaftresistancefortheservice,strength,andextremeeventlimitstatesintheGeneralNotes,asshowninFigure7.8-1-1.

1. AxialResistanceGroupReductionFactors

ThegroupreductionfactorsforaxialresistanceofshaftsforthestrengthandextremeeventlimitstatesshallbetakenasshowninTable7.8.1.1-1.Thesereductionfactorspresumethatgoodshaftinstallationpracticesareusedtominimizeoreliminatetherelaxationofthesoilbetweenshaftsandcaving.Ifthiscannotbeadequatelycontrolledduetodifficultsoilsconditionsorforotherconstructabilityreasons,lowergroupreductionfactorsshallbeusedasrecommendedbythegeotechnicalengineerofrecord.Thesegroupreductionfactorsapplytobothstrengthandextremeeventlimitstates.FortheservicelimitstatetheinfluenceofthegrouponsettlementasrequiredintheAASHTOLRFDandtheAASHTOSEISMICarestillapplicable.



B. Structural Design and Detailing

1. Drilledshaftsshallbedesignedforthelesseroftheplasticforcesor1.2timestheelasticseismicforcesofthecolumnaboveinsinglecolumn/singleshaftfoundations.

2. ConcreteClass5000Pshallbespecifiedfortheentirelengthoftheshaftforwetordryconditionsofplacement.

3. Whenshaftsareconstructedinwater,theconcretespecifiedforthecasingshoringsealshallbeClass4000W.

4. Theassumedconcretecompressivestrengthmaybetakenas0.85ƒ′cforstructuraldesignofshafts.Forseismicdesign,theexpectedcompressivestrengthmaybetakenas1.3timesthisvalueinaccordancewithAASHTOSeismicSection8.4.4.

5. Thepresenceofpermanentsteelcasingshallbetakenintoaccountintheshaftdesign(i.e.forstiffness,andetc.),butthestructuralcapacityofpermanentsteelcasingshallnotbeconsideredforstructuraldesignofdrilledshaftsunlessthedesignconformstoSection15.

6. Minimumcoverrequirementsshallbeasspecifiedbelow:• Diameterlessthanorequalto3′-0″=3″• Diametergreaterthan3′-0″andlessthan5′-0″=4″• Diametergreaterthanorequalto5′-0″=6″

7. Theclearspacingbetweenspiralsandhoopsshallnotbelessthan6″ormorethan9″.Theclearspacingbetweenspiralsorhoopsmaybereducedinthesplicezoneinsinglecolumn/singleshaftconnectionsiftheconcreteisvibrated.

8. ThevolumetricratioandspacingrequirementsoftheAASHTOSEISMICforconfinementneednotbemet.

9. #7through#9weldedlapsplicedhoopsareacceptabletouseprovidedtheyarenotlocatedinpossibleplastichingeregions.Weldedsplicesinhoopsforshaftsshallbecompletedpriortoassemblyoftheshaftsteelreinforcingcage.Whenhoopsareused,theplansshallshowastaggeredsplicepatternaroundtheperimeteroftheshaftsothatnotwoadjacentsplicesarelocatedatthesamelocation.

10.Insinglecolumn/singleshaftconfigurations,thespacingoftheshafttransversereinforcementinthesplicezoneshallmeettherequirementsoftheTRACReporttitled,“Noncontact Lap Splices in Bridge Column-Shaft Connections”.Thefactorkrepresentstheratioofcolumntensilereinforcementtototalcolumnreinforcementatthenominalresistance.Intheupperhalfofthesplicezone,kshallbetakenas1.0.Inthelowerhalfofthesplicezone,thisrationcouldbedeterminedfromacolumnmoment-curvatureanalysis.



11.Longitudinalreinforcementshallbeprovidedforthefulllengthofdrilledshafts.Theminimumlongitudinalreinforcementinthesplicezoneofsinglecolumn/singleshaftconnectionsshallbethelargerof0.75percentAgoftheshaftor1.0percentAgoftheattachedcolumn.Theminimumlongitudinalreinforcementbeyondthesplicezoneshallbe0.75percentAgoftheshaft.Theminimumlongitudinalreinforcementinshaftswithoutsinglecolumn/singleshaftconnectionsshallbe0.75percentAgoftheshaft.

12.Theclearspacingbetweenlongitudinalreinforcementshallnotbelessthan6″ormorethan9″.Ifashaftdesignisunabletomeetthisminimumrequirement,alargerdiametershaftshallbeconsidered.

13.Mechanicalsplicesinlongitudinalbarsshallbeplacedinlowstressregionsandstaggered2′-0″minimum.

14.Whereundersizedpermanentslipcasingisused,provideaminimumofconcretecoverof3″forshaftswithadiameterof4′-0″andlargerand1½″forshaftswithadiameterlessthan4′-0″.

15.ReinforcingbarcentralizersshallbedetailedintheplansasshowninSection7.8.2-5.

15.7.9 Piles and PilingA. PileTypes

PilesfornewpermanentbridgesshallbeCIPconcretepiles.

B. PileGroups

Theminimumcenter-to-centerspacingofpilesshallbe30″or2.5pilediameters.

C. Battered Piles

Batteredpilesshallnotbeusedtoresistlateralloadsforpermanentbridgefoundations.

D. Structural Design and Detailing of CIP Concrete Piles

1. ConcreteClass5000PshallbespecifiedforCIPconcretepiles.Thetop10′ofconcreteinthepileshallbevibrated.

2. Forstructuraldesign,thereinforcementaloneshallbedesignedtoresistthetotalmomentthroughoutthelengthofpilewithoutconsideringstrengthofthesteelcasing.Theminimumreinforcementshallbe0.75percentAg forSDCB,CandDandshallbeprovidedforthefulllengthofthepile.MinimumclearancebetweenlongitudinalbarsshallmeettherequirementsinAppendix5.1-A2.

3. Ifthepiletofooting/capconnectionisnotaplastichingezonelongitudinalreinforcementneedonlyextendabovethepileintothefooting/capadistanceequalto1.0ld(tension).Ifthepiletofooting/capconnectionisaplastichingezonelongitudinalreinforcementshallextendabovethepileintothefooting/capadistanceequalto1.25ld.



4. Transversespiralreinforcementshallbedesignedtoresistthemaximumshearinthepile.Theminimumspiralshallbea#4barat9″pitch.Ifthepiletofooting/capconnectionisnotaplastichingezonethevolumetricrequirementsofAASHTOLRFDSection5.13.4.6neednotbemet.

E. PileSplices

Concretepilesplicesshalldevelopthefullflexuralandaxialresistanceofthepile.

F. Pile Resistance

ThebridgeplansshallincludetheUltimateBearingCapacity(NominalDrivingResistance,Rndr,fordrivenpiles)intonsasshowninFigure7.9.11-1.

15.7.10 Concrete-Filled Steel TubesA. DesignRequirements

Concrete-filledsteeltubes(CFST),reinforcedconcrete-filledsteeltubes(RCFST)andtheirconnectionsshallbedesignedinaccordancewithSection7.10.TheuseofCFSTandRCFSTrequiresapprovalfromtheWSDOTBridgeDesignEngineerwhenusedasaductileelementaspartofanearthquake-resistingsystem.Additionally,theplastichingemodelingparametersandmethodsmustbeapprovedbytheWSDOTBridgeDesignEngineer.



15.8 Walls and Buried Structures15.8.1 Retaining Walls

A. General

DesignofretainingwallsshallbebasedontherequirementsandguidancecitedhereinandinthecurrentAASHTOLRFD,AASHTOSEISMIC,AASHTOLRFD Bridge Construction Specifications,WSDOTGeneral&BridgeSpecialProvisionsandtheStandard Specifications M41-10unlessotherwisecitedherein.

Retainingwallsandtheircomponentsthatareinserviceforamaximumof36monthsareconsideredtobetemporary.TemporaryretainingwallsneednotbedesignedfortheExtremeEventLimitStates.

B. Loads

RetainingwallsandtheircomponentsshallbedesignedforallapplicableloadsdefinedinthecurrentAASHTOLRFDChapter3.

TheliveloadfactorforExtremeEvent-ILimitStateloadcombination,γeqasspecifiedintheAASHTOLRFDTable3.4.1-1forallpermanentretainingwallsshallbetakenequalto0.50.

C. Design of Reinforced Concrete Cantilever Retaining Walls

1. Standard Plan Reinforced Concrete Cantilever Retaining Walls

ThestandardplanreinforcedconcreteretainingwallshavebeendesignedinaccordancewiththerequirementsoftheAASHTOLRFD,4thEdition,2007,andinterimsthrough2008.SeeSection8.1foracompletelistofthedesigncriteriausedforthesewalls.DetailsforconstructionandthemaximumbearingpressureinthesoilaregivenintheStandard Plans SectionD.

2. NonStandard Reinforced Concrete Retaining Walls

Reinforcedconcreteretainingwallscontainingdesignparameterswhichexceedthoseusedinthestandardreinforcedconcreteretainingwalldesignareconsideredtobenon-standard.

Foradditionaldesigncriteria,refertoSection8.1.4B

D. Design of Cantilever Soldier Pile and Soldier Pile Tieback Walls

TypicalsoldierpilewalldetailsareprovidedintheAppendix8.1-A1.

1. GroundAnchors(Tiebacks)

Eitherthe“tributaryareamethod”orthe“hingemethod”asoutlinedinAASHTOLRFDSectionC11.9.5.1shallbeconsideredacceptabledesignprocedurestodeterminethehorizontalanchordesignforce.

Therecommendedfactoreddesignloadoftheanchor,recommendedanchorinstallationangles(typically10°–45°),noloadzonedimensions,andanyotherspecialrequirementsforwallstabilityshallbeasprovidedbythegeotechnicalinvestigationperformedfortheprojectbythegeotechnicalengineerofrecord,andtheassociatedgeotechnicalreportbasedonthatinvestigation.





TheminimumverticalanchorspacingshallbethesameasdefinedinAASHTOLRFDSection11.9.4.2fortheminimumhorizontalanchorspacing.

Theanchorlockoffloadis60percentofthecontrollingfactoreddesignloadfortemporaryandpermanentwalls(seeGeotechnical Design Manual Chapter15).

Permanentgroundanchorsshallhavedoublecorrosionprotectionconsistingofanencapsulation-protectedtendonbondlengthasspecifiedintheWSDOTGeneralSpecialProvisions.TypicalpermanentgroundanchordetailsareprovidedintheAppendix8.1-A1.

Temporarygroundanchorsmayhaveeitherdoublecorrosionprotectionconsistingofanencapsulation-protectedtendonbondlengthorsimplecorrosionprotectionconsistingofgrout-protectedtendonbondlength.

2. Design of Soldier Pile

RefertoSection8.1.5Bfordesigncriteria

3. Design of Lagging

Ifconstructionoperationsarelikelytooccuraboveandbehindthesoldierpilewallalignment,thelaggingshallbedesignedforanadditional250psfsurchargeduetotemporaryconstructionload.

a. TemporaryTimberLagging

TemporarylaggingisasdefinedintheStandard Specifications Section616.3(6).TemporarytimberlaggingshallbedesignedinaccordancewithStandard SpecificationsSection616.3(6)B.

b. PermanentLagging

PermanentlaggingisasdefinedintheStandard Specifications Section6.16.3(6).Permanentlaggingshallbedesignedfor100percentofthelateralloadthatcouldoccurduringthelifeofthewallinaccordancewithAASHTOLRFDSections11.8.5.2and11.8.6forsimplespanswithoutsoilarching.

TimberlaggingshallbedesignedinaccordancewithAASHTOLRFDSection8.6.Thesizeeffectfactor(CFb)shallbeconsidered1.0unlessaspecificsizeisshowninthewallplans.Thewetservicefactor(CMb)shallbe0.85.Theloadappliedtolaggingshallbeappliedatthecriticaldepth.Laggingsizemaybesteppedovertheheightofthewall.

TimberlaggingdesignedasapermanentstructuralelementshallconsistoftreatedDouglasFirLarch,gradeNo.2orbetter.Hemfirwoodspecies,duetotheinadequatedurabilityinwetcondition,shallnotbeusedforpermanenttimberlagging.

4. Design of Fascia Panels

RefertoSection8.1.5Dfordesigncriteria.


http://www.wsdot.wa.gov/publications/manuals/fulltext/M46-03/Chapter15.pdf






E. Design of Structural Earth Walls

1. Pre-approvedProprietaryStructuralEarthWalls

Structuralearth(SE)wallsystemsmeetingestablishedWSDOTdesignandperformancecriteriahavebeenlistedas“preapproved”bytheBridgeandStructuresOfficeandtheMaterialsLaboratoryGeotechnicalBranch.AlistofcurrentpreapprovedproprietarywallsystemsandtheirlimitationsisprovidedintheGeotechnical Design Manual Appendix15D.FortheSEwallshopdrawingreviewprocedure,seetheGeotechnical Design Manual Chapter15.

F. Design of Standard Plan Geosynthetic Walls

DetailsforconstructionaregivenintheStandard Plans SectionD.

G. Design of Soil Nail Walls

SoilnailwallsshallbedesignedinaccordancewiththeFHWAPublicationFHWA-NHI-14-007“Geotechnical Engineering Circular No. 7 Soil Nail Walls”.TheseismicdesignparametersshallbedeterminedinaccordancewiththemostcurrenteditionoftheAASHTOSEISMIC.TypicalsoilnailwalldetailsareprovidedinSection8.1.

H. MiscellaneousItems

RefertoSection8.1.9fordesigncriteria.

I. Joints

Everyjointinthewallshallprovideforexpansion.Forcast-in-placeconstructionaminimumof½inpremoldedfillershallbespecifiedinthejoints.Acompressiblebackupstripofclosedcellpolyethylenefoamorbutylrubberwithasealantonthefrontfaceisusedforprecastconcretewalls.

Forcantileveredandgravitywallsconstructedwithoutatrafficbarrierattachedtothetop,expansionjointspacingshallbeamaximumof24feetoncenters.Forcantileveredandgravitywallsconstructedwithatrafficbarrierattachedtothetop,expansionjointspacingshallbeamaximumof48feetoncentersorthatdeterminedforadequatedistributionofthetrafficcollisionloading.

Forcounterfortwalls,expansionjointspacingshallbeamaximumof32feetoncenters.

Forsoldierpileandsoldierpiletiebackwallswithconcretefasciapanels,jointspacingshallbe24–32feetoncenters.

Nojointsotherthanconstructionjointsshallbeusedinfootingsexceptatbridgeabutmentsandwheresubstructurechangessuchasspreadfootingtopilefootingoccur.Inthesecases,thefootingshallbeinterruptedbya½inpremoldedexpansionjointthroughboththefootingandthewall.Themaximumspacingofconstructionjointsinthefootingshallbe120feet.Thefootingconstructionjointsshouldhavea6inchminimumoffsetfromtheexpansionjointsinthewall.




https://www.fhwa.dot.gov/engineering/geotech/pubs/nhi14007.pdf



15.8.2 Noise Barrier WallsA. General

DesignofnoisebarrierwallsshallbebasedontherequirementsandguidancecitedhereinandinthecurrentAASHTOLRFD,AASHTOSEISMIC,AASHTOLRFD Bridge Construction Specifications,WSDOTGeneral&BridgeSpecialProvisionsandtheStandard SpecificationsM41-10unlessotherwisecitedherein.

B. Loads

NoisebarrierwallsandtheircomponentsshallbedesignedforallapplicableloadsdefinedinthecurrentAASHTOLRFDChapter3.

WindloadsandonnoisebarriersshallbeasspecifiedinChapter3.

Seismicloadshallbeasfollows:

SeismicDeadLoad=As × f × D (8 .2-1)

Inwhich:

A × f≥0.10 (8 .2-2)Where:

As = Peakseismicgroundaccelerationcoefficientmodifiedbyshort-periodsitefactor

D = Deadloadofthenoisebarrierandit’scomponentsf =DeadloadcoefficientasspecifiedinTable8.2-1.

C. Design

1. Standard Plan Noise Barrier Walls

StandardplannoisebarrierwallshavebeendesignedinaccordancewiththeAASHTOGuide Specifications for Structural Design of Sound Barriers,1989andinterimsthrough2002.TheseismicdesignwasbasedonaPGAof0.35gwhichcorrespondstoapeakbedrockaccelerationof0.3gwithanamplificationfactorof1.18forstiffsoil.DetailsforconstructionofthesewallsareshownintheStandard Plans SectionD.

TheDesign ManualChapter740tabulatesthedesignwindspeedsandvariousexposureconditionsusedtodeterminetheappropriatewalltype.

ThedesignparametersusedinthestandardplannoisewallfoundationdesignaresummarizedintheGeotechnical Design ManualChapter17.

2. Non-Standard Noise Barrier Walls

Noisebarrierwallscontainingdesignparameterswhichexceedthoseusedinthestandardnoisebarrierwalldesignareconsideredtobenon-standard.

a. Noise Barrier Walls on Bridges and Retaining Walls

RefertoSection8.2.3B1fordesigncriteria.







15.8.3 Buried StructuresA. General

InaccordancewithcurrentWSDOTpolicy,onlythecast-in-placereinforcedconcreteandprecastconcretearch,box,andellipticalstructuresshallbeusedforburiedhighwayandhydraulicstructureswithspansequalorgreaterthan20feet(measuredparalleltoroadwaycenterline).

ThetermculvertusedinthischapterandintheStandard Specifications M41-10appliestoallburiedhydraulicstructuresonly.Thetermtunnelappliestoallburiedhighwaystructures.

B. WSDOT Designed Standard Culverts

ForWSDOTdesignedStandardCulvertstheWSDOTBridgeandStructuresOfficehasdevelopedculvertstandardsforthePrecastReinforcedConcreteSplitBoxCulvert(PRCSBC)andPrecastReinforcedConcreteThree-SidedStructures(PRCTSS)withspanlengthsfrom20’to60’.SeeSection8.4forthelistofBridgeStandardDrawingsforBuriedStructurescontainingthegeometrytable,typicalsectionsandgeneraldetails.SeeAppendix8.3-B1to8.3-B3fortheDesignCriteriaused.

C. GeneralDesignRequirements

DesignofburiedstructuresshallbeinaccordancewiththerequirementsandguidancecitedhereinandinthecurrentAASHTOLRFD,AASHTOSEISMIC, Special Provisions andtheStandard Specifications M41-10.

Allburiedstructuresshallbedesignedforaminimumservicelifeof75years.

Thespanlengthshallbethewidestopeningfrominteriorfacetointeriorfaceasmeasuredalongthecenterlineoftheroadway.

Allburiedstructureswithspanlengthsgreaterthan20feetshallbeloadratedinaccordancewithSection13.

1. ApplicationofLoads

RefertoSection8.3.3.B

2. Buried Structure Wingwall and Headwall Design

RefertoSection8.3.3.D

3. BuriedStructureSeismicDesign

RefertoSection8.3.3.E

D. Design of Box Culverts

BoxculvertsshallbedesignedinaccordancewithStandard Specifications Section7-02.3(6).RefertoSection8.3.4foradditionaldesigncriteriaspecifictoboxculverts.





E. Design of Precast Reinforced Concrete Three-Sided Structures

PrecastreinforcedconcretethreesidedstructuresshallbedesignedandconstructedinaccordancewithStandard Specifications Section7-02.3(6).Precastreinforcedconcretethreesidedstructuresarelimitedtospansof26feetorless.RefertoSection8.3.5foradditionaldesigncriteriaspecifictoprecastreinforcedconcretethreesidedstructures.

F. Design of Detention Vaults

Designofcompletelyenclosedburieddetentionsvaultsshallnotbepermitted.

G. Design of Tunnels

Ventilation,safetyaccess,firesuppressionfacilities,warningsigns,lighting,emergencyegress,drainage,operation,andmaintenanceareextremelycriticalissuesassociatedwiththedesignoftunnelsandwillrequiretheexpertiseofgeologists,tunnelexperts,andmechanicalengineers.

Formotorvehiclefireprotection,astandardhasbeenproducedbytheNationalFireProtectionAssociation,NFPA502–Standard for Road Tunnels, Bridges, and Other Limited Access Highways.ThisdocumentshallbeusedforallWSDOTtunnels.NFPA502–StandardforRoadTunnels,Bridges,andOtherLimitedAccessHighways,usestunnellengthtodictateminimumfireprotectionrequirements:

300feetorless:nofireprotectionrequirements 300–800feet:minorfireprotectionrequirements 800feetormore:majorfireprotectionrequirements



15.9 Bearings and Expansion Joints15.9.1 ExpansionJoints

A. General Considerations

Bridgesshallbedesignedtoaccommodatemovementsfromallsources,includingthermalfluctuations,concreteshrinkage,prestressingcreep,andelasticpost-tensioningshortening.

Whereseismicisolationbearingsareused,expansionjointsshallbedesignedtoaccommodateseismicmovementsinordertoallowtheisolationbearingstofunctionproperly.

Expansionjointsshallbedesignedtoaccommodatemovementwhileminimizingimpositionofsecondarystressesinthestructure.Expansionjointsystemsshallbesealedtopreventwater,salt,anddebrisinfiltrationtosubstructureelementsbelow.Theyshallalsobedesignedtomaximizedurabilitywhileprovidingarelativelysmoothridingsurface.

Semi-integralconstructionshallbesubjecttothebridgelengthlimitationsstipulatedbelow.Insemi-integralconstruction,concreteenddiaphragmsarecastmonolithicallywiththebridgedeck.Girdersaresupportedonelastomericbearings,whicharesupportedonastuborcantileverabutment.Approachslabanchors,inconjunctionwithacompressionseal,shallconnectthemonolithicenddiaphragmtothebridgeapproachslab.

1. Concrete Bridges

Semi-integralconstructionshallbeusedforprestressedconcretegirderbridgesunder450feetlongandforpost-tensionedsplicedconcretegirderandcast-in-placepost-tensionedconcreteboxgirderbridgesunder400feetlong.Stub“L”andcantilever“L”typeabutmentswithexpansionjointsatthebridgeendsshallbeusedwherebridgelengthexceedsthesevalues.

2. Steel Bridges

“L”typeabutmentsshallbeusedwithexpansionjointsattheendsformultiplespanbridges.

Theuseofintermediateexpansionjointsshallbeavoidedwhereverpossible.

Forthepurposesofthissection,expansionjointsarebroadlyclassifiedintothreecategoriesbasedupontheirtotalmovementrangeasfollows:

SmallMovementRangeJoints TotalMovementRange<=1¾inch

MediumMovementRangeJoints 1¾inch<TotalMovementRange<5inch

LargeMovementRangeJoints TotalMovementRange>=5inch



B. General Design Criteria

Expansionjointsandbearingsshallbedesignedinterdependentlyandinconjunctionwiththeanticipatedbehavioroftheoverallstructure.

Shrinkageanduniformthermalvariationmovementsshallbecalculatedasfollows:

1. ShrinkageEffects

Theshrinkagestrainusedforsizingexpansionjointsthatareinstalled30to60daysfollowingconcretedeckplacementshallbenolessthan0.0002.Thisvalueshallbecorrectedforrestraintconditionsimposedbyvarioussuperstructuretypesasfollows:

∆shrink

= β×µ×Ltrib (9 .1 .2-1)

Where:Ltrib = Tributarylengthofthestructuresubjecttoshrinkageβ = Ultimateshrinkagestrainafterexpansionjointinstallation;estimatedas

0.0002inlieuofmorerefinedcalculationsµ = Restraintfactoraccountingfortherestrainingeffectimposedby

superstructureelementsinstalledbeforetheconcreteslabiscast0.0forsteelgirders,0.5forprecastprestressedconcretegirders,0.8forconcreteboxgirdersandT-beams,1.0forconcreteflatslabs

2. ThermalEffects

InlieuoftheproceduredescribedinAASHTOLRFDArticle3.12.1,uniformthermalmovementrangeshallbecalculatedusingthemaximumandminimumanticipatedbridgesuperstructureaveragetemperaturesnotedbelow.ForthepurposeofcombiningloadcasesinaccordancewithAASHTOLRFDArticle3.4.1,theloadfactorusedforuniformthermal(TU)displacementsshallbetakenas1.0.

ConcreteBridges: 0°Fto100°F

SteelBridges(easternWashington) -30°Fto120°F

SteelBridges(westernWashington) 0°Fto120°F

Totaluniformthermalmovementrangeshallbecalculatedas:

∆temp = α × Ltrib × δT (9 .1 .2-2)

Where:Ltrib = Tributarylengthofthestructuresubjecttothermalvariationα = Coefficientofthermalexpansion;0.000006in./in./°Fforconcrete

and0.0000065in./in./°FforsteelδT Bridgesuperstructureaveragetemperaturerangeasafunctionof

bridgetypeandlocation

InaccordancewithStandard SpecificationsM41-10,contractdrawingsshallstatedimensionsatanormaltemperatureof64°Funlessspecificallynotedotherwise.Constructionandfabricationactivitiesatstructureaveragetemperaturesotherthan64°FrequiretheContractororfabricatortoadjustlengthsofstructuralelementsandconcreteformsaccordingly.




Stripsealandmodularexpansionjointsystemsaretypicallyinstalledinpreformedconcreteblockoutsafterthebridgedeckconcretehasbeencast.Intheseinstances,concreteshallbeplacedintheblockoutwiththeexpansionjointdevicesetatagapthatcorrespondstothetemperatureofthealreadyconstructedbridgedeckatthetimeconcreteisplacedintheblockout.Inordertoaccomplishthis,expansiondevicegapsettingsshallbespecifiedonthecontractdrawingsasafunctionofsuperstructureambientaveragetemperature.Generally,thesesettingsshallbespecifiedfortemperaturesof40°F,64°F,and80°F.

C. SmallMovementRangeJoints

Elastomericcompressionsealsshallbeusedforallsmallmovementrangeapplicationsfornewbridges.Elastomericcompressionsealsorpouredsiliconesealantmaybeusedforrehabilitationofexistingsmallmovementrangeexpansionjointsandwidenings.

1. CompressionSeals

Compressionsealsshallbedesignedandinstalledtoeffectivelysealajointagainstallwateranddebrisinfiltration.Compressionsealsshallextendcontinuouslyacrossthefullroadwaywidthandupintotrafficbarriers.Nofieldsplicesofcompressionsealsareallowed.

Compressionsealsshallbeinstalledagainstsmooth,straightverticalconcretefaces.Concretesurfacesmaybeeitherformedorsawcut.PolyesterorelastomericconcretenosingmaterialshallbeusedforrehabilitationofexistingcompressionsealjointsinaccordancewithSection9.1.3Dbelow.

Fordesignpurposes,theminimumandmaximumworkingwidthsofthesealshallbe40percentand85percentoftheuncompressedwidth.Thesemeasurementsaretakenperpendiculartothejointaxis.Compressedsealwidthatthenormalconstructiontemperatureof64°Fmaybetakenas60percentoftheseal’suncompressedwidth.Forskewedjoints,bridgedeckmovementsshallbeseparatedintocomponentsperpendicularandparalleltothejointaxis.Sheardisplacementofthesealoverthefullexpectedtemperaturerangeshallbelimitedto22percentofitsuncompressedwidth.

2. Rapid-CureSiliconeSealants

Rapid-curesiliconesealantsmaybeinstalledagainsteitherconcreteorsteel.Concreteorsteelsubstratesurfacesshallbethoroughlycleanedbeforethesealantisinstalled.

Rapid-curesiliconesealantsshallbedesignedandinstalledbaseduponthemanufacturer’srecommendations.

3. AsphalticPlugJoints

Asphalticplugjointsarenotallowed.



4. Headers

Expansionjointheadersfornewconstructionshallbethesameclassstructuralconcreteasusedforthebridgedeckandshallbecastintegrallywiththedeck.

Expansionjointheadersinstalledaspartofarehabilitativeand/oroverlayprojectshallbeeitherpolyesterconcreteorelastomericconcrete.ExpansionjointheadersshallbeinaccordancewithGeneralSpecialProvisionsintheRFPAppendix.

ConcreteheadersshallbeconstructedoneachsideofanexpansionjointwhenanHMAoverlayisinstalledatopanexistingconcretebridgedeck.

Forbridgeoverlays,modifiedconcreteoverlay(MCO)materialmayproviderigidsidesupportforanelastomericcompressionsealorarapidcuresiliconesealantbeadwithouttheneedforseparatelyconstructedelastomericconcreteorpolyesterconcreteheaders.Suchmodifiedconcreteoverlayheadersmayutilizeweldedwirefabricasreinforcement.

D. MediumMovementRangeJoints

1. Steel Sliding Plate Joints

Steelslidingplatesshallbelimitedtothefollowingspecificapplications:

i) sidewalksandcrosswalks

ii) modularexpansionjointupturnsattrafficbarriers

iii)bridgedeckapplicationsinvolvingunusualmovements(translationandlargerotations)notreadilyaccommodatedbymodularexpansionjoints.

AllapplicationssubjecttopedestriantrafficshallmeetADArequirementsandshallincludeanon-skidsurface.Non-pedestriantrafficapplicationsshallbegalvanizedorpaintedtoprovidecorrosionresistance.

2. StripSealJoints

Anelastomericstripsealexpansionjointshallconsistofapreformedelastomericglandmechanicallylockedintosteeledgerailsembeddedintotheconcretedeckoneachsideofanexpansionjointgap.Unfoldingoftheelastomericsealaccommodatesmovement.Edgerailsshallbeanchoredtotheconcretedeck.Thesystemshallbedesignedanddetailedtoaccommodatethereplacementofdamagedorwornsealswithminimaltrafficdisruption.

Eitherastandardanchorageoraspecialanchoragemaybeusedforastripsealexpansionjoint.Thespecialanchorageincorporatessteelreinforcementbarloopsweldedtointermittentsteelplates,whichinturnareweldedtothesteelshape.Thespecialanchorageshallbeusedforveryhightrafficvolumesorapplicationssubjecttosnowplowhits.Inapplicationshighlysusceptibletosnowplowhitsandconcomitantdamage,theintermittentsteelplatesshallbedetailedtoprotrude¼″abovethebridgedecksurfacetolaunchthesnowplowbladeandpreventitfromcatchingontheforwardextrusion.

Thestandardanchoragerequiresaminimum7inchdeepblockout.Thespecialanchoragerequiresaminimum9inchdeepblockout.



3. Bolt-down Panel Joints

Bolt-downpaneljointsarenotallowed.

Onbridgeoverlayandexpansionjointrehabilitationprojects,existingbolt-downpaneljointsshallbereplacedwithrapid-curesiliconesealantjointsorstripsealexpansionjoints.

E. LargeMovementRangeJoints

1. Steel Finger Joints

Steelfingerjointsmayonlybeusedwheremodularexpansionjointsareincapableofaccommodatingthemovementsorareotherwisenotfeasible.Elastomericormetaltroughsshallbeinstalledbeneathsteelfingerjointstocatchandredirectrunoffwater.

Thesteelfingersshallbedesignedtosupporttrafficloadswithsufficientstiffnesstoprecludeexcessivevibration.Inadditiontolongitudinalmovement,fingerjointsshallaccommodaterotationanddifferentialverticaldeflectionacrossthejoint.Fingerjointsshallbefabricatedwithaslightdownwardtapertowardtheendsofthefingersinordertominimizepotentialforsnowplowbladedamage.

2. ModularExpansionJoints

Modularexpansionjointsshallprovidewatertightwheelloadtransferacrossexpansionjointopenings.Modularexpansionjointsaregenerallyshippedinacompletelyassembledconfiguration.Modularexpansionjointslongerthan40feet.maybeshippedinsegmentstoaccommodateconstructionstagingand/orshippingconstraints.

a. OperationalCharacteristics

Modularexpansionjointsshallcompriseaseriesofsteelcenterbeamsorientedparalleltotheexpansionjointaxis.Elastomericstripsealsorbox-typesealsshallattachtoadjacentcenterbeams,preventinginfiltrationofwateranddebris.Thecenterbeamsshallbesupportedonsupportbars,whichspanintheprimarydirectionofanticipatedmovement.Thesupportbarsshallbesupportedonslidingbearingsmountedwithinsupportboxes.Polytetrafluoroethylene(PTFE)-stainlesssteelinterfacesshallbeusedbetweenelastomericsupportbearingsandsupportbars.

ModularexpansionjointsystemsshallmeetthefatigueresistancecharacterizationrequirementsspecifiedintheSpecialProvisionformodularexpansionjointsattimeofcontractaward.

CenterbeamfieldsplicesshallbecarefullydesignedandconstructedtomitigatefatiguesusceptibilityinaccordancewiththeSpecialProvisions.



b. MovementDesign

Modularexpansionjointsshallbesizedtoaccommodate115percentofcalculatedtotalmovementrange.Contemporarymodularexpansionjointspermitapproximately3inchesofservicemovementperelastomericsealelement.Extremeeventmovementrangesofupto5inchperelastomericsealelementareallowedprovidedthatsupportbarsandsupportboxesaresizedanddetailedtoaccommodatethelargercumulativemovementwithoutstructurallydamagingthemodularexpansionjointordetachinganyelastomericstripsealelements.Tominimizeimpactandwearonbearingelements,themaximumgapbetweenadjacentcenterbeamsshallbelimitedto3½inch.

Tofacilitatetheinstallationofamodularjointattemperaturesotherthanthe64°Fnormaltemperature,theplansshallspecifyexpansiongapdistancesface-to-faceofedgebeamsasafunctionofthesuperstructuretemperatureatthetimeofinstallation.

c. ReviewofShopDrawingsandStructuralDesignCalculations

Modularexpansionjointsshallbedesigned,tested,fabricated,QA\QCinspected,andinstalledinaccordancetheGeneralSpecialProvisionintheRFPAppendix,includingsubmittalofdesigncalculations,fatiguetestingresults,weldprocedures,andshopdrawings.

Theexpansionjointsystemshallbedesignedtoensurecompleteconcreteconsolidationunderneathallsupportboxes.Aminimumverticalclearanceof2inchshallbeprovidedbetweenthebottomofeachsupportboxandthetopoftheconcreteblockout.Alternatively,whenverticalclearanceisminimal,groutpadsmaybeplacedunderneathsupportboxesbeforecastingtheconcretewithintheblockout.

d. Construction Considerations

Temperatureadjustmentdevicesshallberemovedassoonaspossibleafterconcreteplacementintheblockout.

15.9.2 BearingsA. General Considerations

Bearingsandexpansionjointsshallbedesignedinterdependentlyandinconjunctionwiththeanticipatedbehavioroftheoverallstructure.

B. Force Considerations

Bridgebearingsshallbedesignedtotransferallanticipatedloadsfromthesuperstructuretothesubstructure.BearingdesigncalculationsshallbebasedupontherelevantloadcombinationsandloadfactorsstipulatedintheAASHTOLRFD.Impactneednotbeappliedtoliveloadforcesinthedesignofbearings.



C. MovementConsiderations

Themovementrestrictionsimposedbyabearingshallbecompatiblewiththemovementsallowedbyanadjacentexpansionjoint.Bothbearingsandexpansionjointsshallbedesignedconsistentwiththeanticipatedloadanddeformationbehavioroftheoverallstructure.Designrotationsshallbecalculatedasfollows:

1. ElastomericandFabricPadBearings

Themaximumservicelimitstaterotationforbearingsthatdonothavethepotentialtoachievehardcontactbetweenmetalcomponentsshallbetakenasthesumofunfactoreddeadandliveloadrotationsplusanallowanceforfabricationandconstructionuncertaintiesof0.005radians.

2. HLMR Bearings

High-loadmulti-rotational(HLMR)bearingsincludesphericalbearings,discbearings,cylindricalbearingsandpotbearings.

BothserviceandstrengthlimitstaterotationsshallbeusedinthedesignofHLMRbearings.Theserotationsshallbeshownontheplanstoallowthemanufacturertoproperlydesignanddetailabearing.

DeformableelementssuchaspolyetherurethanediscsandPTFEshallbedesignedforservicelimitstateloadsandrotations.Theservicelimitstaterotationshallincludeanallowanceforuncertaintiesof±0.005radians.

Themaximumstrengthlimitstaterotationshallbeusedtoassurethatpotentialhardcontact(metal-to-metalormetal-to-concrete)isprevented.Fordiscbearings,thestrengthlimitstaterotationshallincludeanallowanceof±0.005radiansforuncertainties.ForotherHLMRbearingsthestrengthlimitstaterotationshallincludeanallowanceof±0.005radiansforfabricationandinstallationtolerancesandanadditionalallowanceof±0.005radiansforuncertaintiesinaccordancewiththeAASHTOLRFD Bridge Design Specifications.

D. Detailing Considerations

HLMRbearingsshallbedesigned,detailed,fabricated,andinstalledtofacilitateinspection,maintenance,andeventualreplacement.Jackingpointsshallbeidentifiedinthecontractdrawingssothatbearingscanbereset,repaired,orreplaced.

PrestressedconcretegirderbridgeshavingendTypeA(semi-integral)neednotbedetailedtoaccommodateelastomericbearingreplacementatabutments.PrestressedconcretegirderbridgeshavingendTypeB(L-typeabutments)shallbedesignedanddetailedtoaccommodateelastomericbearingreplacementatabutments.Specifically,girderstopsandenddiaphragmsshallbedetailedtoaccommodatetheplacementofhydraulicjacks.Thestandardenddiaphragmsforlong-spangirdersmaynothavesufficientflexuralandshearcapacitytosupportjackinginducedstresses.Sufficientsteelreinforcementshallbeprovidedtoaccommodateshearforcesandbendingmomentsinducedbyjacking.(GirderendTypesAandBaredepictedChapter5)Intermediatepiersofprestressedconcretegirderbridgeshavingsteelreinforcedelastomericbearingsshallalsobedesignedanddetailedtofacilitatebearingreplacement.



E. BearingTypes

1. ElastomericBearings

SteelreinforcedelastomericbearingsshallbedesignedusingtheAASHTOLRFDMethodBprocedure.Shearmodulusshallbespecifiedontheplansas165psiat73degFwithoutreferencetodurometerhardness.

ElastomericbearingsshallconformtotherequirementsofAASHTOM251-Plain and Laminated Elastomeric Bridge Bearings.ShimsshallbefabricatedfromASTMA1011Grade36steelunlessnotedotherwiseontheplans.Bearingsshallbelaminatedin½inchthickelastomericlayerswithaminimumtotalthicknessof1inch.Foroverallbearingheightslessthan5inches,aminimumof¼inchofsideclearanceshallbeprovidedoverthesteelshims.Foroverallheightsgreaterthan5inches,aminimumof½inchofsideclearanceshallbeprovided.Liveloadcompressivedeflectionshallbelimitedto1/16inch.Compressivedeadloadandliveloadshallbespecifiedontheplans.

Withrespecttowidth,elastomericbearingsshallbedesignedanddetailedasfollows:

i. Forprestressedconcretewideflangegirders(WF36GtoWF100G),theedgeofthebearingpadshallbesetbetween1inchminimumand9inchmaximuminsideoftheedgeofthegirderbottomflange.

ii. ForprestressedconcreteI-girders,bulb-teegirders,anddeckbulb-teegirders,theedgeofthebearingpadshallbeset1inchinsideoftheedgeofthegirderbottomflange.

iii. Forallprestressedconcretetubgirders,theedgeofthebearingshallbeset1inchinsideoftheedgeofthebottomflange.Bearingpadsforprestressedconcretetubgirdersshallbecenteredclosetothecenterlineofeachweb.

iv. Forallprestressedconcreteslabsonebearingpadandcorrespondinggroutpadisrequiredforeachendoftheprestressedconcreteslab.Thecenterlineofthebearingandgroutpadshallcoincidewiththecenterlineoftheprestressedconcreteslab.Theneedforsteelshimsshallbeassessedduringthebearingdesign.

Inordertofacilitatecompressiveloadtesting,futurebearingreplacement,andverticalgeometrycoordination,thefollowingtableshallbeincludedinthePlans:

Bearing Design TableServiceILimitState

Dead load reaction --------- kipsLive load reaction (w/o impact) --------- kipsUnloaded height --------- inchesLoaded height (DL) --------- inchesShear modulus at 73º F --------- psi



Intheconstructionofprecastprestressedconcretegirderandsteelgirderbridges,elastomericbearingsneednotbeoffsettoaccountfortemperaturevariationduringerectionofthegirders.Girdersmaybesetatopelastomericbearingsattemperaturesotherthanthemeanofthetemperaturerange.Thisshallbestatisticallyreconciledbyassumingamaximumthermalmovementineitherdirectionof:

Δtemp=0.75∙α∙L∙(TMaxDesign–TMinDesign)

whereTMaxDesignisthemaximumanticipatedbridgedeckaveragetemperatureandTMinDesignistheminimumanticipatedbridgedeckaveragetemperatureduringthelifeofthebridge.

Forprecastprestressedconcretegirderbridges,themaximumthermalmovement,Δtemp,shallbeaddedtoshrinkageandlong-termcreepmovementstodeterminetotalbearingheightrequired.Theshrinkagemovementforthisbridgetypeshallbehalfthatcalculatedforacast-in-placeconcretebridge.

2. Fabric Pad Sliding Bearings

Fabricpadslidingbearingsincorporatefabricpadswithapolytetrafluoroethylene(PTFE)-stainlesssteelslidinginterfacetopermitlargetranslationalmovements.

UnfilledPTFEshallbeusedforfabricpadslidingbearings.

UnfilledPTFEshallberecessedhalfitsdepthintoasteelbackingplate,whichshallbebondedtothetopofafabricpad.Thestainlesssteelsheetshallbesealweldedtoasteelsoleplateattachedtothesuperstructure.

a. Fabric Pad Design

Maximumserviceloadaveragebearingpressureforfabricpadbearingdesignshallbe1,200psi.Maximumserviceloadedgebearingpressureforfabricpadbearingdesignshallbe2,000psi.

b. PTFE – Stainless Steel Sliding Surface Design

PTFEshallbeatleast3/16inchthickandrecessed3/32inchintoaminimum½inchthicksteelplatethatisbondedtothetopofthefabricpad.

StainlesssteelsheetshallbefinishedtoaNo.8(Mirror)finishandshallbesealweldedtothesoleplate.

3. Pin Bearings

Steelpinbearingsmaybeusedtosupportheavyreactionswithmoderatetohighlevelsofrotationaboutasinglepredeterminedaxis.

4. RockerandRollerTypeBearings

Rockerbearingsandsteelrollerbearingsarenotallowedfornewbridges.



5. SphericalBearings

WovenPTFEshallbeusedonthecurvedsurfacesofsphericalbearings.Whensphericalbearingsaredetailedtoaccommodatetranslationalmovement,wovenPTFEshallbeusedontheflatslidingsurfacealso.

Sphericalbearingsshallbedetailedwiththeconcavesurfaceorienteddownward.Structuralanalysisoftheoverallstructureshallrecognizethecenterofrotationofthebearingnotbeingcoincidentwiththeneutralaxisofthegirderabove.

Thecontractdrawingsshallshowthediameterandheightofthesphericalbearinginadditiontoalldead,live,andseismicloadings.Soleplateconnections,baseplate,anchorbolts,andanyappurtenancesforhorizontalforcetransfershallbedetailedontheplans.ThesphericalbearingmanufacturershallsubmitshopdrawingsanddetailedstructuraldesigncalculationsofsphericalbearingcomponentsforreviewandcommentbyWSDOT.

6. Disc Bearings

Discbearingscomposedofanannularshapedpolyetherurethanediskwithasteelshear-resistingpininthecentermaybeused.AflatPTFE-stainlesssteelsurfacemaybeincorporatedintothebearingtoalsoprovidetranslationalmovementcapability.

7. SeismicIsolationBearings

Seismicisolationbearingsmaybeused,subjecttotherestrictionsoutlinedinSections4.2.2 and9.3.3.

F. Miscellaneous Details

1. TemporarySupportbeforeGroutingMasonryPlate

ThemasonryplateofanHLMRbearingshallbesupportedonagroutpadthatisinstalledafterthebearingandsuperstructuregirdersabovehavebeenerected.ThissequenceallowstheContractortolevelandslightlyadjustthehorizontallocationofthebearingbeforeimmobilizingit.Twomethodsfortemporarilysupportingthemasonryplateareacceptable:

a. ShimPacks

Multiplestacksofsteelshimplatesmaybeplacedatoptheconcretesurfacetotemporarilysupporttheweightofthegirdersontheirbearingsbeforegrouting.

b. Two-stepGroutingwithCastSleeves

Atwo-stepgroutingprocedurewithcast-in-placevoidedcoresmaybeusedforsmallerHLMRsnotgenerallysubjectedtouplift.Steelstudsareweldedtotheundersideofthemasonryplatetocoincidewiththevoidedcores.Withtemporaryshimsinstalledbetweenthetopoftheconcretesurfaceandtheundersideofthemasonryplate,thevoidedcoresarefullygrouted.Oncethefirststagegrouthasattainedstrength,theshimsareremoved,themasonryplateisdammed,andgroutisplacedbetweenthetopoftheconcretesurfaceandtheundersideofthemasonryplate.



2. Anchor Bolts

Anchorboltsshallbedesignedtoresistallhorizontalshearforcesanddirecttensionforceduetouplift.

AnchorboltsshallbeASTMA449wherestrengthsequaltoASTMA325arerequiredandASTMA354,GradeBD,wherestrengthsequaltoASTMA490arerequired.AnchorboltsshallbeASTMF1554boltswithsupplementalCharpytestrequirementsinapplicationsinwhichtheboltsaresubjecttoseismicloading.

G. ContractDrawingRepresentation

Highloadmulti-rotationalbearingsshallbedepictedschematicallyinthecontractdrawings.Eachbearingmanufacturerhasuniquefabricatingmethodsandproceduresthatallowittofabricateabearingmosteconomically.Depictingthebearingsschematicallywithloadsandgeometricrequirementsprovideseachmanufacturertheflexibilitytoinnovativelyachieveoptimaleconomy.

H. ShopDrawingReview

High-loadmulti-rotationalbearingsshallbedesigned,tested,fabricated,QA\QCinspected,andinstalledinaccordancewiththeSpecialProvisionsintheRFPAppendix,includingsubmittalofdesigncalculationsandshopdrawings.

I. BearingReplacementConsiderations

Bearingsshallbedesignedanddetailedtopermitthereplacementofallelementssubjecttowear.Superstructureandsubstructureelementsshallbedesignedanddetailedtoaccommodateliftingofthesuperstructureusinghydraulicjackstofacilitatebearingelementreplacement.

Forbearingreplacements,theDesign-Buildershallshowanticipatedliftingloadsonthecontractdrawings.Limitationsonliftheightshallalsobespecified.Considerationshallbegiventoliftheightasitrelatestoadjacentexpansionjointselementsandadjoiningsectionsofrailing.Restrictionsondifferentialliftheightbetweenmultiplejacksshallbespecifiedtominimizestressesinducedinadjacentstructuralelements.

Jacksshallbesizedfor200percentofthecalculatedliftingload.


15.10 Signs, Barriers, Bridge Approach Slabs, and Utilities15.10.1 Sign and Luminaire Supports

A. Loads

1. General

ThereferenceusedindevelopingthefollowingofficecriteriaistheAASHTO“LRFD for Structural Supports for Highway Signs, Luminaires, and Traffic Signals,” First Edition Dated 2015, and shall be the basis for analysis and design.

2. DesignLife(Section11.5,AASHTO2015)

a. AnInfinitelifefatiguedesignwillbeusedforluminairesupports,overheadsignstructures,andtrafficsignalstructures.ThenumberofcyclesastructuremustwithstandwillbebasedontheADTTofa75yeardesignlifewitheachtruckinducingonecycleinaccordancewithAASHTOLRFDStandard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals First Edition,dated2015 includinginterims.

b. Roadsidesignstructureswillusea10yeardesignlife.

3. Dead Loads

Sign(includingpanelandwindbeams,doesnot includevert.bracing) 3.25lbs/ft2 Luminaire(effectiveprojectedareaofhead=3.3sqfeet) 60lbs/each FluorescentLighting 3.0lbs/ft StandardSignalHead 60lbs/each MercuryVaporLighting 6.0lbs/ft SignBrackets Calc. StructuralMembers Calc. 5footwidemaintenancewalkway (includingsignmountingbracketsandhandrail) 160lbs SignalHeadw/3lenses (effectiveprojectedareawithbackingplate=9.2sqfeet) 60lbs/each

4. Live Load

Aliveloadconsistingofasingleloadof500lbdistributedover2.0feettransverselytothemembershallbeusedfordesigningmembersforwalkwaysandplatforms.Theloadshallbeappliedatthemostcriticallocationwhereaworkerorequipmentcouldbeplaced,see2015AASHTOSpecifications Section3.6.

5. WindLoads

A3secondgustwindspeedshallbeusedintheAASHTOwindpressureequation.The3secondwindgustmapinAASHTOisbasedonthewindmapinANSI/ASCE7-10.



Thebasicwindspeedof115mphshallbeusedincomputingdesignwindpressureusingEquation3.8.1-1ofAASHTOSection3.8.1. Thisisbasedonthehighriskcategorywithameanrecurrenceintendedof1700yearsperAASHTOTable3.8-1.

TheAlternateMethodofWindPressuresgiveninAppendixCoftheAASHTO2009Specificationsshallnotbeused.

6. Fatigue Design

FatiguedesignshallconformtoAASHTOSection11withtheexceptionoftubeshape.AASHTOdoesnotprovidefatiguecalculationsfortubeshapeswithlessthan8sides.ThereforeincalculatingtheConstantAmplitudeFatigueThreshold,DT(Table11.9.3.1-2,AASHTO2015)wastakentobethelargerouterflattoflatdistanceoftherectangulartube.FatigueCategoriesarelistedinTable11.6-1.OverheadCantileverandBridgeSign&signalstructures,highmastluminaires(HMLT),poles,andbridgemountedsignbracketsshallconformtothefollowingfatiguecategories.

FatigueCategoryI:Overheadcantileversignstructures(maximumspanof30feetandnoVMSinstallation),overheadsignbridgestructures,highlevel(highmast)lightingpoles80feetortallerinheight,bridge-mountedsignbrackets,andallsignalbridges.Gantryorpolestructuresusedtosupportsensitiveelectronicequipment(tolling,weigh-in-motion,transmitter/receiver antennas,transponders,etc.)shallbedesignedforFatigueCategoryI, andshallalsomeetanydeflectionlimitationsimposedbytheelectronicequipmentmanufacturers.

FatigueCategoryII:ForstructuresnotexplicitlyfallingintoCategoryIorIII.

FatigueCategoryIII:Lightingpoles50feetorlessinheightwithrectangular,squareornon-taperedroundcrosssections,andoverheadcantilevertrafficsignalsatintersections(maximumcantileverlength65feet).

Signbridges,cantileversignstructures,signalbridges,andoverheadcantilevertrafficsignalsmountedonbridgesshallbeeitherattachedtosubstructureelements(e.g.,crossbeamextensions)ortothebridgesuperstructureatpierlocations.Mountingthesefeaturestobridgesasdescribedabovewillhelptoavoidresonanceconcernsbetweenthebridgestructureandthesigningorsignalstructure.

The“XYZ”limitationshowninTable10.1.4-2shallbemetforMonotubeCantilevers.The“XYZ”limitationconsistsoftheproductofthesignarea(XY)andthearmfromthecenterlineofthepoststothecenterlineofthesign(Z).SeeAppendix10.1-A2-1fordetails.

7. Ice and Snow Loads

A3psficeloadmaybeappliedaroundallthesurfacesofstructuralsupports,horizontalmembers,andluminaires,butappliedtoonlyonefaceofsignpanels(Section3.7,AASHTO2015).

Walk-throughVMSshallnotbeinstalledinareaswhereappreciablesnowloadsmayaccumulateontopofthesign,unlesspositivestepsaretakentopreventsnowbuild-up.



8. GroupLoadCombinations

Sign,luminaire,andsignalsupportstructuresaredesignedusingtheloadfactorsfromTable10.1.1-1,AASHTO2015.

B. Bridge Mounted Signs

1. Vertical Clearance

AllnewsignsmountedonbridgestructuresshallbepositionedsuchthatthebottomofthesignorlightingbracketdoesnotextendbelowthebottomofthebridgeasshowninFigure10.1.2-1.

Bridgemountedsignbracketsshallbedesignedtoaccountfortheweightofaddedlights,andforthewindeffectsonthelightstoensurebracketadequacyiflightingisattachedinthefuture.

2. Geometrics

a. Signsshallbeinstalledatapproximaterightanglestoapproachingmotorists.Forstructuresaboveatangentsectionofroadway,signsshallbedesignedtoprovideasignskewwithin5degreesfromperpendiculartothelowerroadway(seeFigure10.1.2-2).

b. Forstructureslocatedonorjustbeyondahorizontalcurveofthelowerroadway,signsshallbedesignedtoprovideasignchordskewwithin5degreesfromperpendiculartothechord-pointdeterminedbytheapproachspeed(seeFigure10.1.2-3).

c. Thetopofthesignshallbelevel.

3. Aesthetics

a. Thesupportstructureshallnotextendbeyondthelimitsofthesign.

b. Thesignsupportshallbedetailedinsuchamannerthatwillpermitthesignandlightingbrackettobeinstalledlevel.

4. SignPlacement

a. Signsshallneverbeplacedunderbridgedeckoverhangsordirectlyunderthedriplineofthebridge.

b. Aminimumof2inchesofclearanceshallbeprovidedbetweenbacksideofthesignsupportandedgeofthebridge,seeFigure10.1.2-5.

5. Installation

a. Resinbondedanchorsorcast-in-placeASTMF593Group1,ConditionAanchorrodsshallbeusedtoinstallthesignbracketsonthestructure.Sizeandminimuminstallationdepthshallbegivenintheplansorspecifications.Theresinbondedanchorsshallbeinstallednormaltotheconcretesurface,andshallnotbecoredrilled.Resinbondedanchorsshallnotbeplacedthroughthewebsorflangesofprestressedorpost-tensionedgirders.Resinbondedanchorsshallnotbeusedatoverheadlocationsotherthanwithhorizontalhole/anchoralignment.

b. Bridgemountedsignstructuresshallnotbeplacedonbridgeswithsteelsuperstructures.



6. Installing/ReplacingSignPanelsonExistingBridgeMountedSign Brackets

Wheninstallinganewsignpanelonanexistingbridgemountedsignbracket,theinstallationshallconformtothefollowing.

a. AllhardwareshallbereplacedinaccordancewithStandard Specifications Section9-28.11.

b. Theareaofthenewsignpanelshallnotexceedtheareaoftheoriginallydesignedsignpanel.

c. TheWSDOTinspectionreportforthebridgemountedsignbracketshallbereviewedtoensuretheassemblyisingoodcondition.Ifthereisnoinspectionreport,thenaninspectionshallbeperformedtoestablishthecurrentconditionoftheassembly.

7. MaterialSpecifications

a. MaterialspecificationsshallbeasshowninBridgeStandardDrawings 10.1-A6-1.

b. Allnon-stainlesssteelpartsshallbegalvanizedinaccordancewithAASHTOM111afterfabrication.BoltsandhardwareshallbegalvanizedinaccordancewithAASHTOM232.

C. Monotube Sign Structures Mounted on Bridges

1. Design Loads

DesignloadsforthesupportsoftheSignBridgesshallbecalculatedbasedonassuminga12footdeepsignovertheentireroadwaywidth,underthesignbridge,regardlessofthesignareainitiallyplacedonthesignbridge.ForCantileverdesignloads,guidelinesspecifiedinSection10.1.1shallbefollowed.ThedesignloadsshallfollowthesamecriteriaasdescribedinSection10.1.1.Loadsfromthesignbridgeshallbeincludedinthedesignofthesupportingbridge.

Incaseswhereasignstructureismountedonabridge,thesignstructure,fromtheanchorboltgroupandabove,shallbedesignedtoAASHTOStandard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals,FirstEdition,dated2015,includinginterims.TheconcretearoundtheanchorboltgroupandtheconnectingelementstothebridgestructureshallbedesignedtothespecificationsinthismanualandAASHTOLRFD.LoadsfromthesignstructuredesigncodeshallbetakenasunfactoredloadsforuseinAASHTOLRFD Bridge Design Specifications.

2. Vertical Clearance

VerticalclearanceforMonotubeSignStructuresshallbe20′-0″minimumfromthebottomofthelowestsigntothehighestpointinthetraveledlanes.SeeBridgeStandardDrawings10.1-A1-1,10.1A2-1,and10.1-A3-1forsamplelocationsofMinimumVerticalClearances.


http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#BridgeMounted

http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#BridgeMounted

http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#Sign





3. Geometrics

Signstructuresshallbeplacedatapproximaterightanglestoapproachingmotorists.DimensionsanddetailsofsignstructuresareshownintheWSDOTStandardPlansG-60.10,G-60.20,G-60.30,G-70.10,G-70.20,G-70.30andBridgeStandardDrawings 10.1-A1-1,10.1-A1-2,and10.1-A1-3and10.1-A1-1,10.1-A1-2,and10.1-A1-3.Whenmaintenancewalkwaysareincluded,refertoStandardPlansG-95.10,G-95.20,andG-95.30.

D. Monotube Sign Structures

1. Sign Bridge Conventional Design

Table10.1.4-1providestheconventionalstructuraldesigninformationtobeusedforaSignBridgeLayout,BridgeStandardDrawings 10.1-A1-1;alongwiththeStructuralDetailsheets,whichareBridgeStandardDrawings 10.1-A1-1and10.1-A1-3;andGeneralNotes,BridgeStandardDrawings 10.1-A5-1; andMiscellaneousDetails,Appendix10.1-A5-2.Signbridgespanlengthsshallnotexceed180-feet.

2. Cantilever Conventional Design

Table10.1.4-2providestheconventionalstructuraldesigninformationtobeusedforaCantileverLayout,BridgeStandardDrawings 10.1-A2-1;alongwiththeStructuralDetailsheets,whichareBridgeStandardDrawings 10.1-A2-2and10.1-A2-3;andGeneralNotes,Appendix10.1-A5-1;andMiscellaneousDetails,Appendix10.1-A5-2. Cantileverarmlengthsshallnotexceed35-feet.CantileversignstructuresshallnotbeusedtosupportVMSsigns.

3. Balanced Cantilever Conventional Design

BridgeStandardDrawings 10.1-A3-1;alongwiththeStructuralDetailsheets,BridgeStandardDrawings 10.1-A3-2and10.1-A3-3,GeneralNotes,BridgeStandardDrawings 10.1-A5-1;andMiscellaneousDetails,Appendix10.1-A5-2 providestheconventionalstructuraldesigninformationtobeusedforaBalancedCantileverLayout,BalancedCantileversaretypicallyforVMSsignapplicationsandshallhavethesigndeadloadbalancedwithamaximumdifferenceofone-thirdtotwo-thirdsdistribution.

4. Monotube Sheet Guidelines

ThefollowingguidelinesapplywhenusingtheMonotubeSignStructureBridgeStandardDrawings 10.1-A1-1,10.1-A1-2,and10.1-A1-3;10.1-A2-1,10.1-A2-2,and10.1-A2-3;10.1-A3-1,10.1-A3-2,and10.1-A3-3;10.1A4-1,10.1A4-2,and10.1A4-3;and10.1-A5-1,10.1-A5-2,and10.1-A5-3.

Eachsignstructureshallbedetailedtospecify:

i. SignstructurebaseElevation,Station,andNumber.

ii. TypeofFoundation1,2,or3shallbeusedfortheMonotubeSignStructures,unlessanon-conventionaldesignisrequired.TheaverageLateralBearingPressureforeachfoundationshallbenotedontheFoundationsheet(s).

iii. Ifapplicable,labeltheElevationView“LookingBackonStationing”.

http://www.wsdot.wa.gov/Design/Standards/#SectionG














































5. VMSInstallation

a. VMSunitsshallnotbeinstalledonunbalancedcantileverstructures.

b. VMSinstallationonSignBridgestructuresdesignedinaccordancewithAASHTO2015shallbeinstalledinaccordancewiththefollowing:

i. Onspans120feetandgreateruptotwoVMSunitsmaybeinstalledwithamaximumweightof4,000lbs.each.MaintenancewalkwaysmaybeinstalledbetweenVMSunits,butmaynotexceed160lbs/ft,orexceed50percentofthestructurespanlength.

ii. Onspanslessthan120feetuptothreeVMSunitsmaybeinstalledwithamaximumweightof4,000lbs.each.MaintenancewalkwaysmaybeinstalledbetweenVMSunits,butmaynotexceed160lbs/ft.

c. ThenumberofVMSinstalledonSignBridgestructuresdesignedpriortoAASHTO2015shallbereducedbyoneasdefinedinD.2-aandb.

E. Foundations

1. MonotubeSignStructureFoundationTypes

Thefoundationtypetobeusedshallbebasedonthegeotechnicalinvestigationperformedandgeotechnicalreportcompletedbythegeotechnicalengineerofrecord.Standardfoundationdesignsforstandardplantruss-typesignstructuresareprovidedinStandardPlansG-60.20, G-60.30,G-70.20,andG-70.30. MonotubesignstructurefoundationsareBridgeDesignOfficeconventionaldesignsandshallbeasdescribedinthefollowingparagraphs:

a. FoundationType1,isthepreferredfoundationtype.AfoundationType1consistsofadrilledshaftwithitsshaftcap.ThedesignoftheshaftdepthsshownintheSignBridgeStandardDrawingsarebasedonalateralbearingpressureof2,500psf.ThedesignershallchecktheseshaftdepthsusingLRFDmethodology.ForType1foundationdetailsandshaftdepthsseeSignBridgeStandardDrawings10.1-A4-1and10.1-A4-2.TheGeotechnicalreportforFoundationType1shouldincludethesoilfrictionangle,soilunitweight,allowablebearingpressureandtemporarycasingifrequired.TemporarycasingshallbeproperlydetailedinallFoundationType1sheetsiftheGeotechnicalEngineerrequiresthem.

b. FoundationType2isdesignedforalateralbearingpressureof2,500psf.SeeBridgeStandardDrawing10.1-A4-3forBridgeDesignOfficeconventionalFoundationType2designinformation.ThedesignershallchecktheseshaftdepthsusingLRFDmethodology.

c. FoundationType3replacesthefoundationType2forpoorsoilconditionswherethelateralbearingpressureisbetween2,500psfand1,500psf.SeeBridgeStandardDrawing10.1-A4-3forBridgeDesignOfficeconventionalFoundationType3designinformation.ThedesignershallchecktheseshaftdepthsusingLRFDmethodology.

d. BarrierShapeFoundationsarefoundationsthatincludeabarriershapecaponthetopportionofFoundationTypes1,2,and3.FoundationdetailsshallbemodifiedtoincludeBarrierShapeCapdetails.SeeBridgeStandardDrawing10.1-A5-1detailsasingleslopebarrier.







2. Luminaire,SignalStandard,andCameraPoleFoundationTypes

LuminairefoundationoptionsareshownonWSDOTStandardPlanJ-28.30. SignalStandardandCameraPolefoundationoptionsareprovidedonWSDOTStandardPlansJ-26.10andJ-29.10respectively.

3. Foundation Design

Shafttypefoundationsconstructedinsoilforsignbridges,cantileversignstructures,luminaires,signalstandardsandstrainpolesshallbedesignedinaccordancewiththecurrenteditionoftheAASHTOLRFD Standard Specifications For Highway Signs, Luminaires, and Traffic Signals;Section13.16;DrilledShafts.

NoprovisionsforfoundationtorsionalcapacityareprovidedinSection10.13oftheAASHTOStandard Specifications for Highway Signs, Luminaires, and Traffic Signals.Thefollowingapproachcanbeusedtocalculatetorsionalcapacityofsignstructure,luminaire,andsignalstandardfoundations:

TorsionalCapacity,φTn,φTn=F*tanφD

Where:F =Totalforcenormaltoshaftsurface(kip)

D =Diameterofshaft(feet)φ =Soiltofoundationcontactfrictionangle(degree),usesmallestfor

variablesoils

a. Monotube Sign Bridge and Cantilever Sign Structures Foundation Type1Design

Thestandardembedmentdepth“Z”,showninthetableonMonotubeSignStructure BridgeStandardDrawing10.1-A4-1,shallbeusedasaminimumembedmentdepthandshallbeincreasediftheshaftisplacedonaslopedsurface,oriftheallowablelateralbearingpressuresarereducedfromthestandard2500psf.Thestandarddepthassumedthatthetop4feetoftheC.I.P.capisnotincludedinthelateralresistance(i.e.,shaftdepth“D”inthecodementionedabove),butisincludedintheoverturninglengthofthesignstructure.Thesign structureshaftfoundationGSPsunderSection8-21intheRFPAppendixshallapplyforallFoundationType1shafts.

b. MonotubeSignStructuresFoundationType2and3

ThesefoundationdesignsareBridgeDesignOfficeconventionandshallnotbeadjusted.

c. Monotube Sign Structures Non-Conventional Design Foundations

Thegeotechnicalengineerofrecordshallidentifyanylocationswherethefoundationtypes(1,2,or3)willnotwork.Attheselocations,thedesignforcesarecalculated,usingtheAASHTOLRFD Standard Specifications for Structural Supports for Highway Signs, Luminaires, and traffic Signals,andappliedatthebottomofthestructurebaseplate.Theseforcesarethenconsideredserviceloadsandthenon-conventionaldesignfoundationisdesignedwiththeappropriateService,Strength,and




ExtremeLoadCombinationLimitStatesandcurrentdesignpracticesoftheAASHTOLRFDandthismanual.TheanchorrodarrayshallbeusedfromTables10.1.4-1and10.1.4-2andshallbelongenoughtodeveloptherodsintotheconfinedconcretecoreofthefoundation.Therodlengthandthereinforcementforconcreteconfinement,showninthetopfourfeetoftheFoundationType1,shallbeusedasaminimum.

d. Signal Foundation Design

ThetrafficsignalstandardGSPsintheRFPSection8-20shallapplyforfoundationsinsubstandardsoils.

F. Truss Sign Bridges: Foundation Sheet Design Guidelines

IfaTrusssignstructureisused,refertoWSDOTStandard Plansforfoundationdetails.TherearefouritemsthatshouldbeaddressedwhenusingtheWSDOTStandard Plans,whichareoutlinedbelow.

a. Determineconduitneeds.Ifnoneexist,deleteallreferencestoconduit.Ifconduitisrequired,verifyastosizeandquantity.

b. Showsignbridgebaseelevation,number,dimensionandstation.

c. TheconcretebarriertransitionsectionshallbeinaccordancewiththeStandard Plans.

d. ThequantitiesshallbebasedontheStandard Plansdetailsasneeded.

15.10.2 BridgeTrafficBarriersA. General Guidelines and Policy

ThedesigncriteriafortrafficbarriersonstructuresshallbeinaccordancewithChapter13oftheAASHTOLRFDwiththefollowingsupplementalguidelines.

WSDOTstandard42-inchhighSingleSlopeconcretebarriershallbeusedforbarriersonnewbridgesandbridgeapproachslabs.WSDOTstandard34-inchor42-inchSingleSlopeconcretebarriershallbeusedforbarriersonexistingbridges,bridgerehabilitationprojects,andretainingwalls,includinggeosyntheticwallsandstructuralearthwalls.

Useof32-inchor42-inchF-Shapeconcretebarriershallbelimitedforcontinuityoffstructureorwithinacorridor.UseofPedestrianconcretebarriershallbelimitedforlocationswithsidewalk.Useof42-inchor54-inchcombinationbarriers(32-inchor34-inchconcretebarrierincreasedinheightbymetalrailing)maybeusedonlyifallowedbytheRFPCriteria.SeeChapter10AppendixforavailableWSDOTstandardbridgebarrierdesigns.

BarriersshallbedesignedforminimumTestLevel4(TL-4)designcriteriaregardlessofthebarrierheight.TheTestLevelshallbespecifiedinthePlans.

ATestLevel5(TL-5)barriershallbeusedonnewstructuresfor“T”intersections,forbarriersonstructureswitharadiusofcurvaturelessthan500feet(TL-4isacceptableforbarrierontheinsideofthecurve),locationswithAverageDailyTruckTraffic(ADTT)greaterthan10percent,andlocationswithapproachspeedsat50mphorgreater(e.g.freewayoff-ramps).

SeeAASHTOLRFDChapter13foradditionalTestLevelselectioncriteria.







B. Design Criteria

1. StructuralCapacity

AASHTOLRFDAppendixA13shallbeusedtodesignbarriersandtheirsupportingelements(i.e.deck).

ConcretebarriersshallbedesignedusingyieldlineanalysisasdescribedinAASHTOLRFDSectionA13.3.1.

DeckoverhangssupportingconcretebarriersshallbedesignedinaccordancewithAASHTOLRFDSectionA13.4asmodifiedbySection10.2.4.A.

2. Geometry

Thetrafficfacegeometryispartofthecrashtestandshallnotbemodified.

Concreteclearcovershallmeetminimumconcretecoverrequirementsandshallbeincreasedtoaccommodaterusticationgroovesorpatternsforarchitecturalreasons.Concretecovershallbeincreasedto2½″fortrafficfaceofbarrierforslipformmethodofconstruction.

The3″toedimensionoftheF-ShapebarriershallbeincreasedtoaccommodateHMAoverlaystoamaximumof6″.

Fordesigninganddetailingbridgedeckswithasuperelevationof8percentorless,theexteriorbarrierand/orthemedianbarriershallbeorientedperpendiculartothebridgedeck.Bridgedeckswithasuperelevationofmorethan8percent,thebarrieronthelowsideofthebridgeand/ormedianbarriershallbeorientedperpendiculartoan8percentsuperelevatedbridgedeck,andthebarrieronthehighsideofthebridgeshallbeorientedperpendiculartothebridgedeck.

3. MiscellaneousDesignInformation

SteelreinforcementbarsS1andS2orS3andS4andW1andW2(orequivalentbars)fromChapter10AppendixbarrierstandarddrawingsshallbeincludedintheBarList.

SteelreinforcementbarsS1,S3,AS1,AS3,andW1(orequivalentbars)fromChapter10Appendixbarrierstandarddrawingsshallbeepoxycoated.

AnymodificationstoChapter10AppendixbarrierstandarddrawingsortoWSDOTStandard Plans shallnotalterorcompromisethestructuralintegrityand/orcrashtestperformanceofbarrier.ModificationsshallbesubmittedforreviewandacceptancebyWSDOTforconcurrencewithdesignpolicies.

15.10.3 At Grade Concrete BarriersDifferentialgradeconcretebarrierswithagradedifferencegreaterthan4′-0″shallbedesignedasreinforcedconcreteretainingwallswithatrafficbarrieratthetopandabarriershapeatthecutface.

Differentialgradeconcretebarrierswithagradedifference4′-0″orlessshallbedesignedinaccordancetoAASHTOLRFDbarrierloadingwiththefollowingguidelines.



Fulldepthexpansionjointswithsheardowelsatthetopshallbeprovidedat120′maximumspacing.

Barriershallbecontinuousorhaveshearconnectionsbetweenbarriersectionsifprecast.

A. DifferentialGradeConcreteBarrierDesignCriteria


ThestructuralcapacityofthedifferentialgradeconcretebarriershallbedesignedfortherequiredTestLevel(TL)vehicleimpactdesignforcesinaccordancewithAASHTOLRFDChapters5and13.

Anysectionalongthedifferentialgradeconcretebarriershallnotfailinshear,bending,ortorsionwhenthebarrierissubjectedtotheTLimpactforces.

ThetorsioncapacityofthedifferentialgradeconcretebarriershallbeequaltoorgreaterthanthetrafficbarriermomentgeneratedbytheTLimpactforcesappliedtothetopofthebarrier.

2. Global Stability

GlobalstabilityshallbeinaccordancewithSection10.3.1.A.

3. Geometry

Thetopofthedifferentialgradeconcretebarriershallhaveaminimumwidthof6″withaminimum6″cleardistancetoeachsideofluminaireorsignpoleifmountedontopofthedifferentialgradeconcretetrafficbarrier.ThetransitionflarerateshallfollowtheDesign Manual M22-01.

Barrierbottomshallbeembeddedaminimum6″belowroadway.Roadwaysubgradeandballastshallbeextendedbelowwholewidthofdifferentialgradeconcretebarrier.

B. TrafficBarrierMomentSlabDesignCriteria


ThestructuralcapacityofthetrafficbarriermomentslabshallbedesignedfortherequiredTLimpactforcesinaccordancewithAASHTOLRFDChapters5and13.

Anysectionalongthemomentslabshallnotfailinshear,bending,ortorsionwhenthebarrierissubjectedtotheTLimpactforces.

Themomentslabreinforcementshallbedesignedtoresistforcesdevelopedatthebaseofthebarrier.MomentslabsupportingconcretebarriershallbedesignedinaccordancetoDeckOverhangDesigninaccordancewithAASHTOLRFDSectionA13.4asmodifiedbySection10.2.4.A.

ThetorsioncapacityofthemomentslabshallbeequaltoorgreaterthanthetrafficbarriermomentgeneratedbytheTLimpactforces.

2. Global Stability

See Section10.3.2.B.2.




3. Geometry

Momentslabsshallhaveaminimumwidthof4.0feetmeasuredfromthepointofrotationtotheheeloftheslabandaminimumaveragedepthof0.83feet.

4. SoilReinforcement

DesignofthesoilreinforcementshallbeinaccordancewiththeGeotechnical Design ManualChapter15.

5. WallPanel

ThewallpanelsshallbedesignedtoresistthedynamicpressuredistributionsasdefinedintheGeotechnical Design ManualChapter15.

Thewallpanelshallhavesufficientstructuralcapacitytoresistthemaximum design rupture load for the wall reinforcement designed in accordance with the Geotechnical Design ManualChapter15.

C. Precast Concrete Barrier

ConcretebarrierType2andType4shallbeusedinaccordancetoSection10.3.4.

15.10.4 BridgeTrafficBarrierRehabilitationA. General Guidelines and Policy

WhenidentifiedintheRFP,deficientrailsshallbeimprovedorreplacedwithinthelimitsofroadwayresurfacingprojectsinaccordancetoSection10.4.

RetrofitshallbeanapprovedcrashtestedrailsystemorshallbedesignedtothestrengthrequirementssetforthbySection2ofAASHTOStandard Specifications for Highway Bridges,17thedition.

See Section10.4.4andWSDOT Design Manualforreplacementcriteria.

See Section10.4.5and10.4.6foravailablebridgerailretrofitandbridgerailreplacementdesigns.

B. Design Criteria


Astrengthandgeometricreviewshallberequiredforallbridgerailrehabilitationprojects.TheAASHTOLFDloadof10kipsshallbeusedintheretrofitofexistingtrafficbarriersystemsconstructedpriortotheyear2000.

Ifthestrengthoftheexistingbridgerailandtheirsupportingelements(i.e.deck)areunabletoresista10kipbarrierimpactdesignloadorhasnotbeencrashtested,thenmodificationsorreplacementwillberequiredtoimproveitsredirectionalcharacteristicsandstrength.

IfthedesignofthebridgerehabilitationincludesotherbridgecomponentsthatwillbedesignedusingAASHTOLRFDthenthefollowingminimumequivalentExtremeEvent(CT)trafficbarrierloadingcanbeused:

Flexure=(1.3)*(1.67)*(10kip)/(0.9)=24.10kip

Shear=(1.3)*(1.67)*(10kip)/(0.85)=25.54kip








2. Geometry Standardthriebeamguardrailpostspacingis6′-3″exceptfortheSL-1

WeakPost,whichisat8′-4″.Postspacingcanbeincreasedupto10′-0″ifthethriebeamguardrailisnested(doubledup).

Guardrailshallbecontinuouswithoutgaps. DesignFguardrailendsectionsshallbeusedattheapproachandtrailing

endofthesegaps. StandardPlanthriebeamguardrailtransitionsshallbeusedateachcorner

ofthebridge. PlacementoftheretrofitsystemwillbedeterminedfromtheWSDOT

Design Manual.

15.10.5 Bridge RailingA. General Guidelines and Policy Pedestrianandbicycle/pedestrianrailingsshallbedesignedinaccordancewith

AASHTOLRFDChapter13withthefollowingsupplementalguidelines. Railingsshallbedesignedforvehicularimpactloadorbesuccessfullycrashtested

unlesslocationislowspeed,locationisoutsideofDesignClearZoneasdefinedinDesign Manual Chapter1600,orlocationhasminimalsafetyconsequencefromcollapseofrailing.

Minimumheightof54″shallbeprovidedforbicyclerailingsonstructures. FallProtectionrailingshallmeettherequirementsofWAC296-155. See Section10.5.2foravailablebridgerailingdesigns.

15.10.6 Bridge Approach SlabsBridgeapproachslabsarerequiredforallnewandwidenedbridges.

Bridgerunoffattheabutmentsshallbecarriedoffandcollectedatleast10feetbeyondthebridgeapproachslab.

A. BridgeApproachSlabDesignCriteria

Thestandardbridgeapproachslabdesignisbasedonthefollowingcriteria:

1. ThebridgeapproachslabisdesignedasaslabinaccordancewithAASHTOLRFD.(StrengthLimitState,IM=1.33,noskew).

2. Thesupportattheroadwayendisassumedtobeauniformsoilreactionwithabearinglengththatisapproximately⅓thelengthoftheapproachslab,or25′/3=8′.

3. TheEffectiveSpanLength(Seff),regardlessofapproachlength,isassumedtobe: 25′approach–8′=17′.

4. Longitudinalreinforcingbarsdonotrequiremodificationforskewedapproachesupto30degreesorforslablengthsgreaterthan25′.

5. Thebridgeapproachslabisdesignedwitha2″concretecovertothebottomreinforcing.





B. BridgeApproachSlabDetailing

Theminimumdimensionfromthebridgeis25′.

AS1barsshallbeepoxycoated.Bendingdiagramsshallbeshownforallcustomreinforcement.AllBridgeApproachSlabsheetswillhavetheAP2andAP7bars.Ifthereisatrafficbarrier,thenAP8,AS1,andAS2barsshallbeshown.

C. SkewedBridgeApproachSlabs

Forallskewedabutments,theroadwayendofthebridgeapproachslabshallbenormaltotheroadwaycenterline.Skewsgreaterthan20-degreesrequireanalysistoverifythebottommatreinforcement,andmayrequireexpansionjointmodifications.

Theroadwayendoftheapproachmaybesteppedtoreducethesizeortoaccommodatestagingconstructionwidths.Atnopointshalltheroadwayendoftheapproachslabbecloserthan25′tothebridge.Thesecriteriaapplytobothnewandexistingbridgeapproachslabs.Ifstepped,thedesignshallprovidetheabsoluteminimumnumberofstepsandthelongitudinalconstructionjointshallbelocatedonalaneline.SeeFigure10.6.4-1forclarification.

Inaddition,forbridgeswithtrafficbarriersandskewsgreaterthan20degrees,theAP8barsshallberotatedintheacutecornersofthebridgeapproachslabs.Typicalplacementisshownintheflaredcornersteeldetail,seeFigure10.6.4-2.

D. ApproachAnchorsandExpansionJoints

Forsemi-integralabutmentsorstubabutments,thejointdesignshallbecheckedtoensuretheavailablemovementofthestandardjointisnotexceeded.Forbridgeapproachslabswithbarrier,thecompressionsealshallextendintothebarrier.

LTypeAbutments

UseapinnedconnectioninaccordancewithSection10.6.5.

E. BridgeApproachSlabAdditionorRetrofittoExistingBridges

Bridgeapproachslabsonexistingbridgesshallbepinnedtotheexistingpavementseat,orattachedwithapproachanchors.

Thepinningoptionisonlyallowedonsemi-integralabutmentsasabridgeapproachslabadditionorretrofittoanexistingbridge.Figure10.6.6-1showsthepinningdetail.Asthisdetaileliminatestheexpansionjointbetweenthebridgeapproachslabandthebridge,themaximumbridgesuperstructurelengthislimitedto150′.Additionally,iftheroadwayendofthebridgeapproachslabisadjacenttoPCCProadway,thenthedetailshowninFigure10.6.6-2applies.PCCPdoesnotallowforasmuchmovementasHMAandajointisrequiredtoreducethepossibilityofbuckling.

Whenpinningisnotapplicable,thenthebridgeapproachslabshallbeattachedtothebridgewithapproachanchors.Iftheexistingpavementseatislessthan10inches,theseatshallbemodifiedtoprovideanacceptable,widerpavementseat.



Whenabridgeapproachslabisaddedtoanexistingbridge,thefinalgradeofthebridgeapproachslabconcreteshallmatchtheexistinggradeoftheconcretebridgedeck,includingbridgeswithasphaltpavement.TheexistingdepthofasphaltonthebridgeshallbeshowninthePlansandanequaldepthofasphaltplacedonanewbridgeapproachslab.Iftheexistingdepthofasphaltisincreasedordecreased,thefinalgradeshallalsobeshownonthePlans.

F. BridgeApproachSlabStaging

Ensurestagingfollowstrafficcontrol.

AddmechanicalspliceoptionasshowninFigure10.6.6-3whenneeded.

15.10.7 TrafficBarrieronBridgeApproachSlabsAgapbetweenthebridgeapproachslabandwingwall(orretainingwall)shallbeshowninthedetails.Theminimumgapistwicethelong-termsettlement,or2inchesasshowninFigure10.7-1.

Whenthetrafficbarrierisplacedonthebridgeapproachslab,• Barriershallextendtotheendofthebridgeapproachslab• Conduitdeflectionorexpansionfittingsshallbecalledoutatthejoints• Junctionboxlocationsshallstartandendintheapproach• Thetransversetopreinforcingintheslabshallbesufficienttoresistatrafficbarrierimpactload.

A. BridgeApproachSlaboverWingWalls,CantileverWallsorGeosynthetic Walls

Allwallsthatarecast-in-placebelowthebridgeapproachslabshallcontinuethebarriersoffitlinetogradeasshowninFigure10.7.1-1.

B. BridgeApproachSlaboverSEWalls

ThebarriersoffitlineshallmatchthatfortheSEWbarrierstartingatthebridgeexpansionjointasshowninFigures10.7.2-1and10.7.2-2.

15.10.8 Utilities Installed with New ConstructionA. GeneralConcepts

TheutilitiesincludedunderthissectionarethosedescribedinStandard Specifications Section6-01.10.BridgeplansshallincludeallhardwarespecificationsanddetailsfortheutilityattachmentasdescribedintheRFP.

1. Coating and Corrosion Protection

Whenthebridgeistoreceivepigmentedsealer,anyexposedutilitylinesandhangersshallbepaintedtomatchthebridge.Whenapigmentedsealerisnotrequired,steelutilityconduitsandhangersshallbepaintedorgalvanizedforcorrosionprotection.TheRFPCriteriashallspecifycleaningandpaintingprocedures.



B. Utility Design Criteria

AllutilitiesshallbedesignedtoresistStrengthandExtremeEventLimitsStates.UtilitysupportdesigncalculationsshallbestampedwithaStateofWashingtonProfessionalEngineerstamp,signedanddated.

Positiveresistancetoloadsshallbeprovidedinalldirectionsperpendiculartoandalongthelengthoftheutilityasrequiredbytheutilityengineer.

Dynamicfluidactionduetoloadsshallberesistedoffofthebridge.

Whereutilitiesareinsulated,theinsulationsystemshallbedesignedtoallowtheintendedmotionrangeofthehardwaresupportingtheutility.

Conduitshallberigid.

1. Utility Location

Utilitiesshallbelocated,suchthatafailurewillnotresultindamagetothebridge,thesurroundingarea,orbeahazardtotraffic.Theutilityshallbeinstalledbetweengirders.Utilitiesandsupportsshallnotextendbelowthebottomofthesuperstructure.Utilitiesshallbeinstallednolowerthan1foot0inchesabovethebottomofthegirders.Utilitiesshallnotbeattachedabovethebridgedecknorattachedtotherailingsorposts.

2. TerminationattheBridgeEnds

Utilityconduitandencasementsshallextend10feetminimumbeyondtheendsofthestructure.Utilitiesoffthebridgeshallbeinstalledpriortopavingofapproaches.

3. UtilityExpansion

Theutilitiesshallbedesignedwithasuitableexpansionsystemasrequiredtopreventlongitudinalforcesfrombeingtransferredtobridgemembers.

4. Utility Blockouts

Blockoutsshallbeprovidedinallstructuralmembersthatprohibitthepassageofutilities,suchasgirderenddiaphragms,piercrossbeams,andintermediatediaphragms.Theseblockoutsshallbelargeenoughtofitdeflectionfittings,andshallbeparalleltotheutility.Formultipleutilities,anoteshallbeaddedtotheplansthatthedeflectionfittingsshallbestaggeredsuchthatnofittingislocatedadjacenttoanother,ortheblockoutsshallbedesignedtofitbothfittings.Expansionfittingsshallbestaggered.

5. GasLinesorVolatileFluids

PipelinescarryingvolatilefluidsthroughabridgesuperstructureshallbedesignedinaccordancewithWAC480-93,Gas Companies—Safety, and Minimum Federal Safety Standard,Title49CodeofFederalRegulations(CFR)Sectionpart192. WAC468-34-210,Pipelines - Encasement,describeswhencasingisrequiredforcarryingvolatilefluidsacrossstructures.

http://apps.leg.wa.gov/wac/default.aspx?cite=480-93

http://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title49/49cfr192_main_02.tpl

http://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title49/49cfr192_main_02.tpl

http://apps.leg.wa.gov/wac/default.aspx?cite=468-34-210



6. Water Lines

TransversesupportorbracingshallbeprovidedforallwaterlinestocarryStrengthandExtremeEventLateralLoading.Inboxgirders(closedcell),aruptureofawaterlinewillgenerallyfloodacellbeforeemergencyresponsecanshutdownthewatermain.ThisshallbedesignedforasanExtremeEventIIloadcase,wheretheweightofwaterisadeadload(DC).Additionalweepholesoropengrating,orfulllengthcasingextending10-feetbeyondtheendofthebridgeapproachslabshallbeusedtooffsetthisExtremeEvent(seeFigure10.8.3-1).

7. SewerLines

Sewerlinesshallmeetthesamedesigncriteriaaswaterlines.

8. Electrical(PowerandCommunications)

Telephone,televisioncable,andpowerconduitshallbegalvanizedRigidMetalConduit(RGS)orRigidPolyvinylChlorideConduit(PVC).Wheresuchconduitisburiedinconcretecurbsorbarriersorhascontinuoussupport,suchsupportisconsideredtobeadequate.Wherehangersorbracketssupportconduitatintervals,themaximumdistancebetweensupportsshallbeinaccordancewithSection10.8.6.

C. Box/Tub Girder Bridges

Utilitiesshallbelocatedbetweengirdersorunderthebridgedecksoffitwhenthereinforcedconcreteboxortubgirdersarelessthan4feetinsideclearheight.

ContinuousSupportandConcretePedestals

Specialutilities(suchaswaterorgasmains)inboxgirderbridgesshalluseconcretepedestals.Continuoussupportsshallnotbeused.

D. TrafficBarrierConduit

Allnewbridgeconstructionshallinstalltwo2-inchgalvanizedRigidMetalConduit(RGS)orRigidPolyvinylChlorideConduit(PVC)inthetrafficbarriers.PVCconduitmaybeusedonlyinstationary-formbarriers,andwillconnecttoRGSusingaPVCadaptorwhenexitingthebarrier.RGSconduitmaybeusedinstationary-formbarriers,butitshallbeusedinslipformbarriers.

Eachconduitshallbestubbed-outintoitsownconcretejunctionboxateachcornerofthebridge.

Thegalvanizedsteelconduitshallbewrappedwithcorrosionresistanttapeatleastonefootinsideandoutsideoftheconcretestructure,andthisrequirementshallbesostatedontheplans.Thecorrosionresistanttapeshallbe3MScotch50,Bishop5,NashuaAVI10,orapprovedequal.

Pullboxesshallbeprovidedatamaximumspacingof180feet.Forfiberopticsonly,spacingshallnotexceed360feet.ThepullboxsizeshallconformtothespecificationsoftheNationalElectricCodeorbeaminimumof8inchesby8inchesby18inchestofacilitatepullingofwires.Galvanizedsteelpullboxes(orjunctionsboxes)shallmeetthespecificationsofthe“NEMAType4X”standardforstationary-formbarrier,shallmeetthespecificationsofthe“NEMA3R”



andbeadjustableindepthforslipformbarrier,andtheNEMAjunctionboxtypeshallbestatedontheplans.Stainlesssteelpullboxesmaybeusedasanoptiontothegalvanizedsteel.

Inthecaseofexistingbridges,anarea2feetinwidthshallbereservedforconduitbeginningatapointeither4feetor6feetoutsidethefaceofusableshoulder.

E. ConduitTypes

AllelectricalconduitsshallbegalvanizedRigidMetalConduit(RGS)orRigidPolyvinylChlorideConduit(PVC).

F. UtilitySupports

Allutilityinstallationsshalladdresstemperatureexpansioninthedesignofthesystemorexpansiondevices.

Utilitysupportsshallbedesignedsothatanyloadsimposedbytheutilityinstallationdonotoverstresstheconduit,supports,bridgestructure,orbridgemembers.

Designsshallprovidelongitudinalandtransversesupportforloadsfromgravity,earthquakes,temperature,inertia,etc.

a. PipeHangers

Verticalsupportsshallbespacedat5footmaximumintervalsfortelephoneandpowerconduits,andataspacingtoresistdesignloadsforallotherutilities.Forheavypipesovertraffic(10″watermainorlarger),aSafetyFactorof1.5shallbeusedtoresistverticalloadsforStrengthdesign.

Thecast-in-placeinsertshallbeatleast6″longandhotdippedgalvanizedinaccordancewithAASHTOM111 or AASHTOM232.

Theinsertshallnotinterferewithreinforcementinthebridgedeck.Theinsertsshallbeinstalledlevellongitudinallyandtransversely.

Transversesupportsshall,ataminimum,belocatedateveryotherverticalsupport.BridgeStandardDrawings10.8-A1-1and10.8-A1-2depicttypicalutilitysupportinstallationsandplacementatabutmentsanddiaphragms.

15.10.9 UtilityInstallationonExistingBridgesUtilityinstallationonexistingbridgesshallbeinaccordancewithSection10.9.

15.10.10 Resin Bonded AnchorsFastsetepoxyanchorsshallnotbeusedforresinbondedanchors.

Forresinbondedanchorsusedinpermanentsustainedtensionapplications,theadhesiveanchorsystemsshallbetestedforlongtermsustainedloadperformanceinaccordancewithACI355.4.

Undercutanchorsshallbestainlesssteel.

https://bookstore.transportation.org/item_details.aspx?ID=2384

https://bookstore.transportation.org/item_details.aspx?ID=1634

http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#Utility

http://www.wsdot.wa.gov/Bridge/Structures/StandardDrawings.htm#Utility



15.10.11 Drainage DesignAlldrainagesystemexpansionjointsshallbewatertight.

1. Geometrics

Bridgesshallhaveaminimumtransverseslopeof.02′/feetandaminimumlongitudinalslopeof0.5percent.

2. Hydrology

Hydrologicalcalculationsaremadeusingtherationalequation.A10yearstormeventwitha5minutedurationistheintensityusedforallinletsexceptforsagverticalcurveswherea50yearstormintensityisrequired.

3. OnBridgeSystems

Drainsshallonlybeplacedonbridgestructureswhenrequiredbybridgedeckdrainagehydraulicsanalysisandwherealignmentandsuperelevationgeometrycannotbeadjustedtocompensate.Theminimumpipediametershallbe6incheswithnobendsgreaterthan45°withinthesystem.


15.11 Detailing PracticesStructuraldetailingshallmeettherequirementsofthisChapter.

15.11.1 Standard PracticesA. Drawing Orientation and Layout Control

• Contractplansshallbeprinted,sealed,signedandsubmittedon11″×17″paper.Alternatively,theContractplansmaybesubmittedinanelectronicformatacceptedbyWSDOTencryptedwithavalidelectronicsignature.

• Drawingsshallbeorganizedsotheintentofthedrawingiseasilyunderstood.

1. Northarrowshallbeplacedonlayoutsandfooting/foundationlayouts.

2. Relateddetailsshallbegroupedtogetherinanorderlyarrangement,lineduphorizontallyandverticallyanddrawntothesamescale.

3. ThePlanviewlayoutofstructuresshallbeorientedfromlefttorightinthedirectionofincreasingstateroutemileposts.Forlayoutsofexistingbridgesundergoingwidening,expansionjointorthriebeamretrofit,orotherstructuralmodification,thisorientationrequirementmayresultinthebridgelayoutbeingoppositefromwhatisshownintheoriginalplans.Insuchcases,thebridgelayoutorientationandpieridentificationshallbelaidouttobeconsistentwiththeWSDOTBridgePreservationOfficeinspectionrecords.

4. ExceptfortheLayout,wallelevationsaretoshowtheexposedfaceregardlessofdirectionofstationing.TheLayoutsheetstationingshallreadincreasinglefttoright.Theelevationsheetsshallrepresenttheviewinthefieldasthewallisbeingbuilt.

B. Lettering

1. General

i. Letteringshallbeuppercaseonly,slantedatapproximately68degrees.Generaltextistobeapproximately⅛″high.

ii. Textshallbeorientedsoastobereadfromthebottomorrightedgeofthesheet.

iii. Detailtitlesshallbeasimilarfontasgeneraltext,abouttwiceashighandofaheavierweight.Theyshallbeunderlinedwithasinglelinehavingthesameweightasthelettering.

iv. TheTrueTypefonts“BridgeTechItalic”(BRIDT__.TTF,BRIDRG__.TTF)shallbeused,exclusiveoftitleblocks,andmaybedownloadedforusebytheDesign-BuilderfromtheWSDOTBridgeandStructureswebsite.

2. Dimensioning

i. Adimensionshallbeshownonceonadrawing.Duplicationandunnecessarydimensionsshallbeavoided.

ii. Alldimensionfiguresshallbeplacedabovethedimensionline,sothattheymaybereadfromthebottomortherightedgeofthesheet.



iii. Whendetailsorstructuralelementsarecomplex,utilizetwodrawings,onefordimensionsandtheotherforreinforcingbardetails.

iv. Dimensions12inchesormoreshallbegiveninfeetandinchesunlesstheitemdimensionedisconventionallydesignatedininches(forexample,16″øpipe).

v. Dimensionsthatarelessthanoneinchoveranevenfoot,thefractionshallbeprecededbyazero(forexample,3′-0¾″).

vi. Dimensionsshallbeplacedoutsidetheview,preferablytotherightorbelow.However,intheinterestofclarityandsimplicityitmaybenecessarytoplacethemotherwise.

C. Line Work

1. Alllineworkshallbeofsufficientsize,weight,andclaritysothatitcanbeeasilyreadona11″x17″sheet.

2. Thelinestyleusedforaparticularstructuraloutline,centerline,etc.,shallbekeptconsistentwhereverthatlineisshownwithinasetofplans.

3. Lineworkshallhaveappropriategradationsofwidthtogivelinecontrast.Careshallbetakenthatthethinlinesaredenseenoughtoshowclearlywhenreproduced.

4. Whendrawingstructuralsectionsshowingreinforcingsteel,theoutlineofthesectionsshallbeaheavierlineweightthanthereinforcementsteel.

5. Theorderoflineprecedence(whichofapairofcrossinglinesisbroken)shallbeasfollows:

i. Dimensionlinesareneverbroken.

ii. Leaderlinefromacallout.

iii. Extensionline.

D. Scale

1. Plansshallbedrawnusingstandardarchitecturalorengineeringscales.Alldetailsshallbeaccuratelydrawntoscale.Scalesshallnotbeshownintheplans.

2. Theminimumscaleforasectiondetailwithrebarshallbe⅜″=1′.Theminimumscaletobeusedonsteeldetailsshallbe¾″=1′.

E. GraphicSymbols

Graphicsymbolsshallbeinaccordancewiththefollowing:

1. Structuralsteelshapes:SeetheAISC Steel Construction Manual.

2. Weldingsymbols:Seethe Lincoln Welding Chart.

3. SymbolsforhatchingdifferentmaterialsareshownonAppendix11.1-A2.

https://www.aisc.org/publications/steel-construction-manual-resources/

https://app.aws.org/mwf/attachments/64/225364/AWSWeldSymbolchart.pdf



F. Structural Sections, Views and Details

1. Wheneverpossible,sectionsandviewsshallbetakenlookingtotheright,aheadonstationing,ordown.

2. Theorientationofadetaildrawingshallbeidenticaltothatoftheplan,elevation,etc.,fromwhichitistaken.Wherethereisaskewinthebridgeanysectionsshallbetakenfromplanviews.

3. Thedefaultvieworientationistobelookingaheadonstationing.Otherorientationsshallbenoted.

4. Acircledividedintoupperandlowerhalvesshallidentifystructuralsections,views,anddetails.ExamplesareshowninAppendix11.1-A3.

5. Breaksinlinesareallowableprovidedthattheirintentisclear.

G. Miscellaneous

1. Calloutarrowsshallcomeoffeitherthebeginningorendofthesentence.Thismeansthetoplineoftextforarrowscomingofftheleftofthecalloutorthebottomlineoftextforarrowspointingright.

H. RFC Revisions

1. ChangesmadetoReleasedForConstruction(RFC)plansheetsshallbecloudedwiththeexceptionoftableentrieswhichshallbeshadedinaccordancewiththePlans Preparation Manual Appendix5.Subsequentchangesshallbecloudedorshadedandthecloudingandshadingfrompreviouschangesshallberemoved.

2. Changesshallbemarkedwithanumberinacircleinatriangle.

3. ChangesshallbenotedintherevisionblockatthebottomofthesheetusingLucidaConsolefont12pt.

I. Title Block

1. Theprojecttitleshallbedisplayedintheplansheettitleblock.ThetitleconsistsofLine1specifyingthehighwayroutenumber(s),Line2andpossiblyLine3specifyingthetitleverbiage.Bridgestructuresshallhaveafourthline,inasmallerfont,tospecifythebridgenameandnumberinaccordancewiththeBridge ListM23-09andSections2.3.1.Aand2.3.2.A.

2. Thehighwayroutenumber(s)inLine1shallbeconsistentwithWSDOTnamingpractice.Interstateroutes(5,82,90,182,205,405,and705)shallbespecifiedasI-(number).USroutes(2,12,97,97A,101,195,197,395,and730)shallbespecifiedasUS(number).AllotherroutesshallbespecifiedasSR(number).ProjectsincludingtwohighwayroutesshallincludebothroutenumbersinLine1,asin“US2AndI-5”.Projectsincludingthreeormorehighwayroutesshallbespecifiedwiththelowestnumberedroute,followedby“EtAl”,asin“SR14EtAl”.


http://www.wsdot.wa.gov/publications/manuals/fulltext/M22-31/Appendix5.pdf

http://www.wsdot.wa.gov/publications/manuals/fulltext/M23-09/BridgeList.pdf



J. ReinforcementDetailing

1. Contractdocumentsshallconveyallnecessaryinformationforfabricationofreinforcingsteel.InaccordancewithStandard Specifications Section6-02.3(24),reinforcingsteeldetailsshowninthebarlistshallbeverifiableintheplansandothercontractdocuments.

2. Size,spacing,orientationandlocationofreinforcementshallbeshownontheplansheets.

3. Reinforcementshallbeidentifiedbymarknumbersinsidearectangle.Reinforcingbarmarksshallbecalledoutatleasttwice.Thereinforcementincludingthespacingiscalledoutinoneview(suchasaplanorelevation).Thereinforcementwithoutthespacingiscalledoutagaininatleastoneotherviewtakenfromadifferentangle(suchasasection).

4. EpoxycoatingforreinforcementshallbeshownintheplansbynotinganEinsideatriangle.

5. Thespacingforreinforcementshallbeonadimensionlinewithextensionlines.Donotpointtoasinglebarandcalloutthespacing.Reinforcementspacingcalloutsshallincludeadistance.Ifthedistanceisanunusualnumber,giveamaximumspacing.Donotuse“equalspaces”asin“23equalspaces=18′-9″.Also,neverusetheword“about”asin23spaces@about10″=18′-9″.Insteadtheseshouldread“23spaces@10″max.=18′-9″.

6. Reinforcementgeometryshallbeclearinplandetails.Congestedareas,oddlybentbars,etc.canbeclarifiedwithadditionalviews/details/sectionsoradjacentbendingdiagrams.Inbendingdiagrams,reinforcementdimensionsshallbegivenout-to-out.Itmaybenecessarytoshowedgesofreinforcementwithtwoparalleledgelinestoclearlyshowworkingpointsanddimensions.

7. Reinforcementlengths,angles,etc.neednotbecalledoutwhentheycanbedeterminedfromstructuralmembersizes,coverrequirements,etc.Anchorage,embedmentandextensionlengthsofreinforcementshallbedimensionedintheplans.

8. StandardhooksinaccordancewithAASHTOLRFDSection5.10.2.1neednotbedimensionedorcalledout,butshallbedrawnwiththeproperangle(90º,135ºor180º).SeismichooksperAASHTOLRFD Section5.10.2.2(usedfortransversereinforcementinregionsofexpectedplastichinges)shallbecalledoutontheplanswhenevertheyareused.

9. Thelocation,lengthandstaggeroflapsplicesshallbeshownontheplansheets.Tablesofapplicablelapsplicelengthsareacceptablewithassociatedstaggerrequirements.Type,locationandstaggerofmechanicalandweldedsplicesofreinforcementshallbeshown.

10.WhereconcretecoverrequirementsdifferfromthosegiveninthestandardnotesorStandard Specifications Section6-02.3(24)C,theyshallbeshownintheplans.Itshallbeclearwhetherthecoverrequirementreferstotiesandstirrupsorthemainlongitudinalbars.





15.11.2 BridgeOfficeStandardDrawingsandOfficeExamplesA. General

TheBridgeandStructuresOfficeprovidesstandarddrawingsandexamplesheetsofvariouscommonbridgeelements.

B. Use of Standards

Thestandarddrawingsshallbeconsideredasnothingmorethanexamplesofitemslikegirdersortrafficbarrierswhichareoftenusedandareverysimilarfromjobtojob.

Theyshallbemodifiedtofittheparticularaspectsofthestructure.Theyarenotintendedtobeincludedinaplansetwithoutclosescrutinyforapplicabilitytothejob.

15.11.3 Plan SheetsPlansheetsshallbeassembledintheorderofconstructionandshallincludetheitemslistedbelow.• Layout• GeneralNotes/ConstructionSequence• Footing/FoundationLayout• Piles/Shafts• Abutments• IntermediatePiers/Bents• BearingDetails• FramingPlan• TypicalSection• Girders/Diaphragms• BridgeDeckReinforcement(Planandtransversesection)• ExpansionJoints(ifneeded)• TrafficBarrier• BridgeApproachSlab

A. Layout• TheLayoutsheetshallcontain,butisnotlimitedto:

– PlanViewwithascendingstationsfromlefttoright– ElevationViewshownasanoutsideviewofthebridgeandshallbevisuallyalignedwiththeplanview.

• Alignmentlines,verticalcurvesandroadwaysuperelevationdiagrams.– Testholelocations(designatedby3/16inchcircles,quartered)toplanview.– Elevationviewoffootings,seals,piles,etc.ShowelevationatBottomoffootingand,ifapplicable,thetypeandsizeofpiling.

– Generalnotesabovelegendonrighthandside,usuallyinplaceofthetypicalsection.



– Title“LAYOUT”inthetitleblockandsheetnumberinthespaceprovided.– Otherfeatures,suchaslighting,conduit,signs,excavation,riprap,etc.asdeterminedbythedesigner.

B. General Notes/Construction Sequence

C. Footing Layout• AnabutmentwithaspreadfootinghasaFootingLayout.AnabutmentwithpilesandpilecaphasaFoundationLayout.

• TheFootingLayoutisaplanofthebridgewhosedetailsarelimitedtothoseneededtolocatethefootings.Theintentofthefootinglayoutistominimizethepossibilityoferroratthisinitialstageofconstruction.

• TheFoundationLayoutisaplanofthebridgewhosedetailsarelimitedtothoseneededtolocatetheshaftsorpiles.TheintentoftheFoundationlayoutistominimizethepossibilityoferroratthisinitialstageofconstruction.

• Otherrelatedinformationand/ordetailssuchaspedestalsizes,andcolumnsizesareconsideredpartofthepierdrawingandshouldnotbeincludedinthefootinglayout.

• TheFootingLayoutshouldbeshownonthelayoutsheetifspaceallows.Itneednotbeinthesamescale.Whenthegeneralnotesandfootinglayoutcannotbeincludedonthefirst(layout)sheet,thefootinglayoutshouldbeincludedonthesecondsheet.

• Longitudinally,footingsshouldbelocatedusingthesurveylinetoreferencesuchitemsasthefooting,centerlinepier,centerlinecolumn,orcenterlinebearing,etc.

• Whensealsarerequired,theirlocationsandsizesshouldbeclearlyindicatedonthefootinglayout.

• TheWallFoundationPlanforretainingwallsissimilartotheFootingPlanforbridgesexceptthatitalsoshowsdimensionstothefrontfaceofwall.

• Appendix11.1-A4isanexampleofafootinglayoutshowing:– Thebasicinformationneeded.– Themethodofdetailingfromthesurveyline.

D. Piles/Shafts

E. Abutment• Bridgeelementsthathavenotyetbeenbuiltwillnotbeshown.Forexample,thesuperstructureisnottobeshown,dashedornot,onanysubstructuredetails.

• Elevationinformationforsealsandpilesorshaftsmaybeshownontheabutmentorpiersheets.

• Viewsaretobeorientedsothattheyrepresentwhatthecontractororinspectorwouldmostlikelyseeontheground.Pier1elevationisoftenshownlookingbackonstationing.AnoteshouldbeaddedundertheElevationPier1titlesaying“Shownlookingbackonstationing”.

F. IntermediatePiers/Bents• Eachpiershallbedetailedseparatelyasageneralrule.Iftheintermediatepiersareidenticalexceptforheight,thentheycanbeshowntogether.



F. Bearing Details

G. FramingPlan• GirderLinesmustbeidentifiedintheplanview(Gir.A,Gir.B,etc.).

H. TypicalSection• Girderspacing,whichistiedtothebridgeconstructionbaseline• Bridgedeckthickness,aswellaswebandbottomslabthicknessesforboxgirders

• “A”dimension• Limitsofpigmentedsealer• Profilegradeandpivotpointandcrossslopes• Utilitylocations• Curbtocurbroadwaywidth• Soffitanddripgroovegeometry

I. Girders/Diaphragms• PrestressedgirdersheetscanbecopiedfromtheBridgeandStructuresOfficelibrarybuttheyshallbemodifiedtomatchtheprojectrequirements.

J. BridgeDeckReinforcement• Planandtransversesectionviews

K. ExpansionJoints

L. TrafficBarrier• TrafficbarriersheetscanbecopiedfromtheStandard Plansbuttheymustbemodifiedtomatchtheprojectrequirements.

M.BridgeApproachSlab• ApproachslabsheetscanbecopiedfromtheStandard Plansandmodifiedasnecessaryfortheproject.

N. Barlist• Thebarlistsheetsdonotrequirestampingbecausetheyarenotofficiallypartofthecontractplanset.

15.11.5 Structural SteelA. General

Flatpiecesofsteelaretermedplates,bars,sheetsorstrips,dependingonthedimensions.

B. Bars

Upto6incheswide,0.203inch(3/16inch)andoverinthickness,or6inchesto8incheswide,0.230inch(7/32inch)andoverinthickness.

C. Plates

Over8incheswide,0.230inch(7/32inch)andoverinthickness,orover48incheswide,0.180in(11/64inch)andoverinthickness.





D. Strips

Thinnerpiecesupto12incheswidearestripsandover12inchesaresheets.AcompletetableofclassificationmaybefoundintheAISCManual of Steel Construction,8thEd.Page6-3.

E. Labeling

Thefollowingtableshowstheusualmethodoflabelingsomeofthemostfrequentlyusedstructuralsteelshapes.Notethattheinchessymbol(″)isomitted,butthefootsymbol(′)isusedforlengthincludinglengthslessthanafoot.

Page 11-10 Bridge Design Manual M 23-50 August 2006

Detailing Practice Chapter 11

E. Labeling

• The following table shows the usual method of labeling some of the most frequently used structural steel shapes. Note that the inches symbol (“) is omitted, but the foot symbol (‘) is used for length including lengths less than a foot.



15.11.6 Aluminum Section DesignationsThedesignationsusedinthetablesaresuggestedforgeneraluse.

Section Designation ExampleI-Beams I DEPTH × WT 14 × 3 .28Wide-Flange Sections WF DEPTH × WT WF4 × 4 .76Wide-Flange Sections, Army-Navy Series

WF(A-N) DEPTH × WT WF(A-N)4 × 1 .79

American Standard Channels

C DEPTH × WT C4 × 1 .85

Special Channels CS DEPTH × WT CS4 × 3 .32Wing Channels CS(WING) WIDTH × WT CS(WING)4 × 0 .90Army-Navy Channels C(A-N) DEPTH × WT C(A-N)4 × 1 .58Angles L LL × LL × TH L3 × 3 × 0 .25Square End Angles LS LL × LL × TH LS2 × 2 × 0 .187Bulb Angles BULB L LL1 × LL2 × TH1 × TH2 BULB L4 × 3 .5 × 0 .375 × 0 .375Bulb Angle, Army-Navy Series

BULB L(A-N) LL1 × LL2 × TH1 × TH2

BULB L(A-N) 3 × 2 × 0 .188 × 0 .188

Tees T DEPTH × WIDTH × WT T4 × 4 × 3 .43Army-Navy Tees T(A-N) DEPTH × WIDTH × WT T(A-N)4 × 4 × 2 .27Zees Z DEPTH × WIDTH × WT Z4 × 3 .06 × 2 .85Plates PL TH × WIDTH PL¼ × 8Rods RD DIA RD 1Square Bars SQ SDIM SQ 4Rectangle Bars RECT TH × WIDTH RECT¼ × 4Round Tubes ODIA OD × TH WALL 4OD × 0 .125 WALLSquare Tubes ODIM SQ × TH WALL 3SQ × 0 .219 WALLRectangle Tubes DEPTH × WIDTH RECT × TH

WALL4 × 1 .5 RECT × 0 .104 WALL

WT - WEIGHT in LB/FT based on density of 0 .098 TH - THICKNESS, LL - LEG LENGTH, DIA – DIAMETER ODIA - OUTSIDE DIAMETER, ODIM - OUTSIDE DIMENSION SDIM - SIDE DIMENSIONAll lengths are in inches

15.11.7 AbbreviationsAbbreviationsshallbedefinedinthecontractdocuments.



15.12 Bridge Load Rating15.12.1 General

Loadratingsshallbecompletedforallnew,widened,orrehabilitatedbridgeswheretherehabilitationalterstheloadcarryingcapacityofthestructure.LoadratingsshallbedoneimmediatelyafterthedesigniscompletedandratingcalculationsshallbefiledseparatelyinaccordancewithSection13.4andfilesshallbeforwardedtoWSDOT’sLoadRatingEngineer.Afinalstampedandsignedloadratingshallbeprovidedatleast90-dayspriortoopeninganybridgerequiringloadratingtotraffic.FinalapprovaloftheloadratingofabridgeshallrestwithWSDOT’sLoadRatingEngineer.

NewbridgesshallberatedbasedontheLoadandResistanceFactorRating(LRFR)methodinaccordancewiththeAASHTOManual For Bridge Evaluation(MBE), Chapter13ofthismanualandthischapter.NBIratingsshallbebasedontheHL-93truckandshallbereportedasaratingfactor.

15.12.2 Load Rating SoftwareForprestressedconcretegirderbridgesandX-Beams,useBridgeLinktoloadratestructuralelements.ForallothercaseswhereBridgeLinkcannotbeused,suchasbutnotlimitedto,orsteelstructuresorsegmentalboxes,CSiBridgeshallbeused.ObtainWSDOT’sLoadRatingEngineer’sapprovalfortheuseofanyothersoftwarepriortocommencinganywork.

Formorecomplexstructuressuchassteelcurvedgirdersandarches,differentsoftwaremaybeusedtoanalyzetheloadsafterobtainingapprovalfromWSDOT’sLoadRatingEngineer.AcceptablesoftwarecurrentlyincludesCSiBridge.

LoadsandcapacitiesshallbetabulatedinamannerthatwillmakeitsimpleforWSDOTtomanipulatethedatainthefuture.MethodoftabulationshallbeapprovedbyWSDOT’sLoadRatingEngineerpriortocommencinganywork.MicrosoftExcelshallbeusedfortabulation,andallcellsinthespreadsheetsshallbeunlockedandanyhiddencodeorfunctionsshallbeexplainedthoroughlyinthereport.Handcalculationsshallbeprovidedtoverifyallspreadsheets.


15.99 ReferencesAASHTOLRFD Bridge Design Specifications,LatestEditionandInterims.AmericanAssociationofStateHighwayandTransportationOfficials(AASHTO),Washington,D.C.

AASHTOGuide Specifications for LRFD Seismic Bridge Design (SEISMIC),LatestEditionandInterims.AmericanAssociationofStateHighwayandTransportationOfficials(AASHTO),Washington,D.C.

AASHTOStandard Specifications for Highway Bridges,17thedition

AASHTOManual for Bridge Evaluation

ACI355.4-11(2014) “Qualification of Post-Installed Adhesive Anchors in Concrete and Commentary,” AmericanConcreteInstitute,FarmingtonHills,MI.

WSDOTBridge Inspection ManualM36-64

WSDOTGeotechnical Design Manual M46-03

WSDOT Design ManualM22-01

WSDOTConstruction Manual M41-01

WSDOTLocal Agency GuidelinesM36-63

WSDOTStandard Specifications for Road, Bridge, and Municipal Construction (Standard Specifications) M41-10

WSDOT Standard Plans M21.01

WSDOTHydraulics ManualM23-03

WashingtonUtilitiesandTransportationCommissionClearance Rules and Regulations Governing Common Carrier Railroads

AmericanRailwayEngineeringandMaintenanceAssociation(AREMA)Manual for Railroad Engineering.Note:Thismanualisusedasthebasicdesignandgeometriccriteriabyallrailroads.UsethesecriteriaunlesssupersededbyFHWAorWSDOTcriteria.

TheUnionPacificRailroad“Guidelines for Design of Highway Separation Structures over Railroad (Overhead Grade Separation)”

https://bookstore.transportation.org/collection_detail.aspx?ID=15




http://www.wsdot.wa.gov/publications/manuals/fulltext/M41-01/Construction.pdf




http://www.wsdot.wa.gov/Design/Standards/#SectionM


http://apps.leg.wa.gov/wac/default.aspx?cite=480-60&full=true

http://apps.leg.wa.gov/wac/default.aspx?cite=480-60&full=true



https://www.fhwa.dot.gov/bridge/130416.cfm

https://www.fhwa.dot.gov/bridge/130416.cfm



This page intentionally left blank.

Documents

Bridge Design Manual M 23-50 Chapter 15 Structural Design