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Transmittal NumberPT 12-022

DateMarch 2012

Publication Title / Publication NumberBridge Design Manual M 23-50.11

Originating OrganizationEngineering and Regional Operations, Bridge and Structures Office

Remarks and InstructionsThe complete manual, revision packages, and individual chapters can be accessed at www.wsdot.wa.gov/publications/manuals/m23-50.htm.

Please contact Joe Fahoum at 360-705-7193 or [email protected] with comments, questions, or suggestions for improvement to the manual.

For updating printed manuals, page numbers indicating portions of the manual that are to be removed and replaced are shown below.

Chapter Remove Pages Insert PagesTitle Page i – ii i – iiContents vii – x vii – xChapter 1 General Information 1.3-1 – 1.3-18 1.3-1 – 1.3-18Appendix 1.5-A3 QA/QC Signature Sheet 1.5-A3-1 – 1.5-A3-2 1.5-A3-1 – 1.5-A3-2Chapter 4 Seismic Design and Retrofit 4-i – 4.99-2 4-i – 4.99-2

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Washington State Department of Transportation Bridge and Structures Office PO Box 47340 Olympia, WA 98504-7340

Joe FahoumApproved By Signature

Bridge Design Manual (LRFD)M 23-50.11

March 2012

Engineering and Regional OperationsBridge and Structures Office

Americans with Disabilities Act (ADA) InformationMaterials can be provided in alternative formats by calling the ADA Compliance Manager at 360-705-7097. Persons who are deaf or hard of hearing may contact that number via the Washington Relay Service at 7-1-1.

Title VI Notice to the PublicIt is Washington State Department of Transportation (WSDOT) policy to ensure no person shall, on the grounds of race, color, national origin, or sex, as provided by Title VI of the Civil Rights Act of 1964, be excluded from participation in, be denied the benefits of, or be otherwise discriminated against under any of its federally funded programs and activities. Any person who believes his/her Title VI protection has been violated may file a complaint with WSDOT’s Office of Equal Opportunity (OEO). For Title VI complaint forms and advice, please contact OEO’s Title VI Coordinator at 360-705-7082 or 509-324-6018.

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www.wsdot.wa.gov/publications/manuals

WSDOT Bridge Design Manual M 23-50.06 Page viiJuly 2011

Contents

Appendix2.2-A1 BridgeSiteDataGeneral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2-A1-1Appendix2.2-A2 BridgeSiteDataRehabilitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2-A2-1Appendix2.2-A3 BridgeSiteDataStreamCrossing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2-A3-1Appendix2.2-A4 PreliminaryPlanChecklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2-A4-1Appendix2.2-A5 RequestForPreliminaryGeotechnicalInformation. . . . . . . . . . . . . . . . . 2.2-A5-1Appendix2.3-A1 BridgeStageConstructionComparison . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-A1-1Appendix2.3-A2 BridgeRedundancyCriteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3-A2-1Appendix2.4-A1 BridgeSelectionGuide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4-A1-1Appendix2.7-A1 StandardSuperstructureElements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7-A1-1Appendix2-B-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-1Appendix2-B-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-2Appendix2-B-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-3Appendix2-B-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-4Appendix2-B-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-5Appendix2-B-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-6Appendix2-B-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-7Appendix2-B-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-8Appendix2-B-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-B-9

Chapter 3 Loads3.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-1

3.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2-1

3.3 Load Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3-1

3.4 Limit States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4-1

3.5 Load Factors and Load Combinations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5-13.5.1 LoadFactorsforSubstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5-2

3.6 Loads and Load Factors for Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6-1

3.7 Load Factors for Post-tensioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7-13.7.1 Post-tensioningEffectsfromSuperstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7-13.7.2 SecondaryForcesfromPost-tensioning,PS . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7-1

3.8 Permanent Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8-13.8.1 DeckOverlayRequirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.8-1

3.9 Live Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-13.9.1 LiveLoadDesignation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-13.9.2 LiveLoadAnalysisofContinuousBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-13.9.3 LoadingforLiveLoadDeflectionEvaluation . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-13.9.4 DistributiontoSuperstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-13.9.5 BridgeLoadRating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9-3

3.10 Pedestrian Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.10-1

3.11 Wind Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.11-13.11.1 WindLoadtoSuperstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.11-13.11.2 WindLoadtoSubstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.11-13.11.3 WindonNoiseWalls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.11-1

3.12 Noise Barriers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.12-1

3.13 Earthquake Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.13-1

Page viii WSDOT Bridge Design Manual M 23-50.11 March 2012

Contents

3.14 Earth Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.14-1

3.15 Force Effects Due to Superimposed Deformations . . . . . . . . . . . . . . . . . . . . . . . 3.15-1

3.16 Other Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.1 Buoyancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.2 CollisionForceonBridgeSubstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.3 CollisionForceonTrafficBarrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.4 ForcefromStreamCurrent,FloatingIce,andDrift . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.5 IceLoad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-13.16.6 UniformTemperatureLoad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.16-1

3.99 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.99-1Appendix3.1-A1 TorsionalConstantsofCommonSections . . . . . . . . . . . . . . . . . . . . . . . . 3.1-A1-1Appendix3.1-B1 HL-93LoadingforBridgePiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-B1-1

Chapter4 SeismicDesignandRetrofit4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1-1

4.2 WSDOTModificationstoAASHTO Guide Specifications for LRFD Seismic Bridge Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14.2.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14.2.2 EarthquakeResistingSystems(ERS)RequirementsforSDCsCandD . . . . . . . . 4.2-14.2.3 SeismicGroundShakingHazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.4 SelectionofSeismicDesignCategory(SDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.5 TemporaryandStagedConstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.6 LoadandResistanceFactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.7 BalancedStiffnessRequirementsandBalancedFrameGeometry

Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.8 SelectionofAnalysisProceduretoDetermineSeismicDemand. . . . . . . . . . . . . . . 4.2-84.2.9 MemberDuctilityRequirementforSDCsCandD . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.10 LongitudinalRestrainers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.11 Abutments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.12 Foundation–General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.13 Foundation–SpreadFooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.14 Procedure3:NonlinearTimeHistoryMethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.15 IeffforBoxGirderSuperstructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.16 FoundationRocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.17 DrilledShafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.18 LongitudinalDirectionRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.19 LiquefactionDesignRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.20 ReinforcingSteel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.21 ConcreteModeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.22 ExpectedNominalMomentCapacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.23 InterlockingBarSize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.24 SplicingofLongitudinalReinforcementinColumnsSubjecttoDuctility

DemandsforSDCsCandD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-11

WSDOT Bridge Design Manual M 23-50.11 Page ix March 2012

Contents

4.2.25 Development Length for Column Bars Extended into Oversized Pile Shafts for SDCs C and D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-11

4.2.26 Lateral Confinement for Oversized Pile Shaft for SDCs C and D . . . . . . . . . . . . .4.2-114.2.27 Lateral Confinement for Non‑Oversized Strengthened Pile Shaf for SDCs C

and D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.28 Requirements for Capacity Protected Members. . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.29 Superstructure Capacity Design for Transverse Direction (Integral Bent Cap)

for SDCs C and D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-124.2.30 Superstructure Design for Non Integral Bent Caps for SDCs B, C, and D . . . . . . 4.2-124.2.31 Joint Proportioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-124.2.32 Cast-in-Place and Precast Concrete Piles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14

4.3 Seismic Design Requirements for Bridge Widening Projects . . . . . . . . . . . . . . . 4.3-14.3.1 Seismic Analysis and Retrofit Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3-14.3.2 Design and Detailing Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3-4

4.4 Seismic Retrofitting of Existing Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.1 Seismic Analysis Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.2 Seismic Retrofit Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.3 Computer Analysis Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.4 Earthquake Restrainers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-24.4.5 Isolation Bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-2

4.5 Seismic Design Requirements for Retaining Walls . . . . . . . . . . . . . . . . . . . . . . . . 4.5-14.5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5-1

4.99 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.99-1

Appendix 4‑B1 Design Examples of Seismic Retrofits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-B1-1Appendix 4-B2 SAP2000 Seismic Analysis Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-B2-1

Page x WSDOT Bridge Design Manual M 23-50.06 July 2011

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Chapter 5 Concrete Structures5.0 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0-1

5.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-15.1.1 Concrete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-15.1.2 ReinforcingSteel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-65.1.3 PrestressingSteel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-95.1.4 PrestressLosses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-135.1.5 PrestressingAnchorageSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-165.1.6 Post-tensioningDucts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1-16

5.2 Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-15.2.1 Service andFatigueLimitStates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-15.2.2 Strength-LimitState . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-25.2.3 Strut-and-tieModel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-75.2.4 DeflectionandCamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-75.2.5 ConstructionJoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-95.2.6 InspectionLightingandAccess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2-10

5.3 ReinforcedConcreteBoxGirderBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-15.3.1 BoxGirderBasicGeometries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-15.3.2 Reinforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-55.3.3 Crossbeam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-135.3.4 EndDiaphragm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-165.3.5 DeadLoadDeflectionandCamber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-185.3.6 ThermalEffects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-195.3.7 Hinges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-195.3.8 DrainHoles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3-19

5.4 Hinges and Inverted T-Beam Pier Caps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4-1

5.5 Bridge Widenings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-15.5.1 ReviewofExistingStructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-15.5.2 AnalysisandDesignCriteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-25.5.3 RemovingPortionsoftheExistingStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-55.5.4 AttachmentofWideningtoExistingStructure . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-55.5.5 ExpansionJoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-175.5.6 PossibleFutureWideningforCurrentDesigns . . . . . . . . . . . . . . . . . . . . . . . . 5.5-185.5.7 BridgeWideningFalsework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-185.5.8 ExistingBridgeWidenings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5-18

5.6 Precast Prestressed Girder Superstructures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-15.6.1 WSDOTStandardGirderTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-15.6.2 DesignCriteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-35.6.3 FabricationandHandling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.6-115.6.4 SuperstructureOptimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-155.6.5 RepairofDamagedGirdersatFabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-185.6.6 RepairofDamagedGirdersinExistingBridges . . . . . . . . . . . . . . . . . . . . . . . 5.6-185.6.7 ShortSpanPrecastPrestressedBridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-215.6.8 PrecastPrestressedConcreteTubGirders . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-225.6.9 PrestressedGirderCheckingRequirement . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6-235.6.10 ReviewofShopPlansforPretensionedGirders . . . . . . . . . . . . . . . . . . . . . . . . 5.6-23

Chapter 1 General Information

WSDOT Bridge Design Manual M 23-50.11 Page 1.3-1March 2012

1.3 Quality Control/Quality Assurance (QC/QA) Procedure1.3.1 GeneralA. The purpose of the QC/QA procedure is to improve the quality of the structural designs and plans.

The key element to the success of this process is effective communication between all parties. The goals of the QC/QA procedure are:• Designedstructuresthatimprovepublicsafetyandmeetstateregulations.• DesignedstructureswhichmeettherequirementsoftheWSDOTBridge Design Manual M23‑50,AASHTOLRFDBridgeDesignSpecifications,currentstructuralengineeringpractices,andgeometriccriteriaprovidedbytheRegion.

• Designedstructuresthatareaestheticallypleasing,constructible,durable,economical,inspectable, and require little maintenance.

• Designcontractdocumentsthatmeetthecustomer’sneeds,schedule,budget,andconstructionstaging requirements.

• Structuraldesigncostsareminimized.• Anorganizedandindexedsetofdesigncalculationsareproduced.Designcriteriaandassumptionsareincludedinthefrontaftertheindex.

• Planqualityismaximized.• TheQA/QCprocedureallowsforchange,innovation,andcontinuousimprovement.

Thegoalsarelistedinorderofimportance.Ifthereisaconflictbetweengoals,themoreimportantgoal takes precedence.

TheUnitSupervisordeterminesprojectassignmentsandtheQC/QAprocesstobeusedinpreparationofthestructuraldesign.TheintentoftheQC/QAprocessistofacilitateplanproductionefficiencyandcost‑effectivenesswhileassuringthestructuralintegrityofthedesignandmaximizingthequalityof the structural contract documents.

B. TheBridgeandStructuresOfficeQC/QAprocedureisacomponentofthegeneralWSDOTtemplateforprojectmanagementprocess.IncludedaspartofthecurrentWSDOTprojectmanagementprocessareprojectreviewsatspecificmilestonesalongtheprojecttimeline.TheexpectedcontentofthedocumentsbeingreviewedateachspecificmilestonearedescribedintheDeliverableExpectationsMatrixdevelopedandimplementedbytheWSDOTDesignOfficeinMay2006.Thismatrixcanbeviewed via the link www.wsdot.wa.gov/projects/projectmgmt/online_guide/delivery_expectation_matrix/de_matrix.pdf.

TheoverallmatrixisgenericforWSDOTdesign,butthereisalineinthematrixthatoutlinesthespecificcontentexpectationsforstructures(bridgesretainingwalls,noisebarrierwalls,overheadsignstructures,etc.).This“structuresspecific”matrixlineincludesalinktoaseparatematrix.Thisstructuresmatrixcanbeviewedviathelinkwww.wsdot.wa.gov/projects/projectmgmt/online_guide/delivery_expectation_matrix/bridge.pdf.

TheBridgePreliminaryPlanasdescribedinChapter2isequivalenttotheGeometricReviewmilestoneofthegenericWSDOTmatrixandthePermittingSubmittalReviewmilestoneofthestructurespecificmatrix.

IntermediatestageconstructabilityreviewsconductedforcertainprojectsbyRegionDesignPEOfficesorLocalAgenciesareequivalenttotheGeneralPlansReviewmilestoneofthegenericWSDOTmatrixandtheIntermediatePS&ESubmittalReviewmilestoneofthestructurespecificmatrix.

http://www.wsdot.wa.gov/Publications/Manuals/M23-50.htm

www.wsdot.wa.gov/projects/projectmgmt/online_guide/delivery_expectation_matrix/de_matrix.pdf




General Information Chapter 1

Page 1.3-2 WSDOT Bridge Design Manual M 23-50.11 March 2012

TheBridgePlansturn‑inasdescribedinSection12.4.3isequivalenttothePreliminaryContractReviewmilestoneofthegenericWSDOTmatrixandthePS&EPre‑submittalReviewmilestoneofthestructurespecificmatrix.

TheBridgePS&Eturn‑inasdescribedinSection12.4.3isequivalenttotheFinalContractReviewmilestoneofthegenericWSDOTmatrixandtheFinalPS&ESubmittalReviewmilestoneofthestructurespecificmatrix.

1.3.2 Design/Check ProceduresA. PS&EPreparedbyWSDOTBridgeandStructuresOffice

1. Design Team – ThedesignteamusuallyconsistsoftheDesigner(s),Checker(s),StructuralDetailer(s),andaSpecificationandEstimateEngineer,whoareresponsibleforpreparingasetofcontractdocumentsonorbeforethescheduledduedate(s)andwithinthebudgetallocatedfortheproject.Onlargeprojects,theUnitSupervisormaydesignateadesignertobeaProjectCoordinator with additional duties, such as: assisting the supervisor in communicating with the Region,coordinatingandcommunicatingwiththeGeotechnicalBranch,andmonitoringtheactivities of the design team.

TheQC/QAproceduresmayvarydependingonthetypeandcomplexityofthestructurebeingdesigned,andtheexperiencelevelofthedesignteammembers.Moresupervision,review,andcheckingmayberequiredwhenthedesignteammembersarelessexperienced.Ingeneral,itisagoodpracticetohavesomeexperienceddesignersoneverydesignteam.Alldesignteammembersshouldhavetheopportunitytoprovideinputtomaximizethequalityofthedesignplans.

2. Designer Responsibility – The designer is responsible for the content of the contract plan sheets, includingstructuralanalysis,completenessandcorrectness.Agoodsetofexampleplans,whichisrepresentativeofthebridgetype,isindispensableasanaidtolessexperienceddesignersanddetailers.

Duringthedesignphaseofaproject,thedesignerwillneedtocommunicatefrequentlywiththeUnitSupervisorandotherstakeholders.Thisincludesacquiring, finalizingorrevisingroadwaygeometrics, soil reports, hydraulics recommendations, and utility requirements. Constructability issuesmayalsorequirethatthedesignercommunicatewiththeRegionorConstructionOffice.Thedesignermayhavetoorganizeface‑to‑facemeetingstoresolveconstructabilityissuesearlyinthedesignphase.ThebridgeplansmustbecoordinatedwiththePS&EpackagesproducedconcurrentlybytheRegion.

ThedesignershalladvisetheUnitSupervisorassoonaspossibleofanyscopeandprojectcostincreasesandthereasonsfortheincreases.TheUnitSupervisorwillthennotifytheRegionprojectofficeifthedeliveryschedulewillhavetobechanged.IfRegionconcurswithachangeinthedeliverydate,theUnitSupervisorwillnotifytheBridgeProjectsEngineerortheBridgeSchedulingEngineerofthereviseddeliverydates.

ThedesignerorProjectCoordinatorisresponsibleforprojectplanningwhichinvolvesthe following:

a. Determinesscopeofwork,identifiestasksandplansorderofwork.

b. Preparedesigncriteriathatareincludedinthefrontofthedesigncalculations.ComparestaskswithBDMofficepracticeandAASHTObridgedesignspecifications.

(1) Insuresthat designguidelinesaresufficient?

(2) JustificationfordeviationfromBridge Design Manual/AASHTO?




(3) Justificationfordesignapproach?

(4) Justificationfordeviationfromofficepracticesregardingdesignanddetails?

(5) Otherdifferences.

c. MeetwiththeRegiondesignstaffandotherprojectstakeholdersearlyinthedesignprocesstoresolveasmanyissuesaspossiblebeforeproceedingwithfinaldesignanddetailing.

d. Identifycoordinationneedswithotherdesigners,units,andoffices.

e. Earlyintheproject,thebridgesheetnumberingsystemshouldbecoordinatedwiththeRegiondesignstaff.Forprojectswithmultiplebridges,eachsetofbridgesheetsshouldhavea unique set of bridge sheet numbers.

f. AtleastmonthlyorasdirectedbythedesignUnitSupervisor:

(1) UpdateProjectScheduleandListofSheets.

(2) Estimatepercentcomplete.

(3) Estimatetimetocomplete.

(4) WorkwithUnitSupervisortoadjustresources,ifnecessary.

g. DeveloppreliminaryquantitiesforallcostestimatesafterthePreliminaryPlanstage.

h. Nearendofproject:

(1) Developquantities,Not Included in Bridge Quantity List, and Special Provisions Checklist thataretobeturnedinwiththeplans.(SeeSection12.4.4).

(2) PreparetheBarList.

(3) Coordinateallfinalchanges,includingreviewcommentsreceivedfromtheBridgeSpecificationsandEstimatesEngineer.RefertoSection12.4.3(B).

(4) MeetwithRegiondesignstaffandotherprojectstakeholdersattheconstructabalityreview/roundtablereviewmeetingstoaddressfinalprojectcoordinationissues.

ThedesignershouldinformtheUnitSupervisorofanyareasofthedesign,whichshould receive special attention during checking and review.

(5) PreparetheQA/QCChecklist,andobtainsignatures/initialsasrequired.Thisappliestoallprojectsregardlessoftypeorimportance(bridges,walls,signstructures,overlay,trafficbarrier,etc.).RefertoAppendix1.5‑A3‑1.

The design calculations are prepared by the designer and become a very important record document.Designcalculationswillbeareferencedocumentduringtheconstructionofthestructure and throughout the life of the structure. It is critical that the design calculations be userfriendly.Thedesigncalculationsshallbewellorganized,clear,properlyreferenced,and include numbered pages along with a table of contents. The design calculations shall be archived.Computerfilesshouldbearchivedforuseduringconstruction,intheeventthatchanged conditions arise. Archive-ready design and check calculations shall be bound and submittedtotheUnitSupervisorconcurrentlywiththeturn‑inoftheBridgePS&Esubmittal.Calculations shall be stored in the design unit until completion of construction. After construction,theyshallbesenttoarchives.(SeeSection1.3.8ArchivingDesignCalculations,DesignFiles,andS&EFiles).

The designer or another assigned individual is also responsible for resolving construction problemsreferredtotheBridgeOfficeduringthelifeofthecontract.TheseissueswillgenerallybereferredthroughtheBridgeTechnicalAdvisor,theUnitSupervisor,theConstructionSupportUnit,ortheHQConstruction‑Bridge.



3. Checker Responsibility – ThecheckerisresponsibletotheUnitSupervisorfor“qualityassurance”ofthestructuraldesign,whichincludescheckingthedesign,plansandspecificationstoassureaccuracyandconstructability.TheUnitSupervisorworkswiththecheckertoestablishthe level of checking required. The checking procedure for assuring the quality of the design will varyfromprojecttoproject.Followingaresomegeneralcheckingguidelines:

a. Design Calculations – may be checked by either of two methods:

(1) Designcalculationsmaybecheckedwitha line‑by‑linereviewandinitialingbythechecker.Ifitismoreefficient,thecheckermaychoosetoperformhis/herownindependent calculations.

(2) Iterativedesignmethodsmaybebestcheckedbyreviewofthedesigner’scalculations,whilestandardandstraight‑forwarddesignsmaybemostefficientlycheckedwithindependent calculations. All the designer and checker calculations shall be placed in one design set.

(3) Revisionofdesigncalculations,ifrequired,istheresponsibilityofthedesigner.

b. Structural Plans

(1) Thechecker’splanreviewcommentsarerecordedonacopyofthestructuralplans,including details and bar lists, and returned to the designer for consideration. These check prints are a vital part of the checking process, and shall be preserved. If the checker’scommentsarenotincorporated,thedesignershouldprovidejustificationfornot doing so. If there is a difference of opinion that cannot be resolved between the designerandchecker,theUnitSupervisorshallresolveanyissues.CheckprintsshallbesubmittedtotheUnitSupervisoratthetimeof100%PS&Eturn‑in.

(2) IfassignedbytheUnitSupervisor,astructuraldetailershallperformacompletecheckofthegeometryusingCADDorhandcalculations.

(3) Revisionofplans,ifrequired,istheresponsibilityofthedesigner.

c. Quantities and Barlist

(1) Thecheckershallprovideanindependentsetofquantitycalculations.Thesetogetherwiththedesigner’squantitycalculationsshallbeplacedinthejobfile.

(2) ResolutionofdifferencesbetweenthedesignerandcheckershallbecompletedbeforetheBridgePS&Esubmittal.Thecheckershallalsocheckthebarlist.

4. Structural Detailer Responsibility – The structural detailer is responsible for the quality and consistencyofthecontractplansheets.ThestructuraldetailershallensurethattheBridgeOfficedraftingstandardsasexplainedinChapter11ofthismanualareupheld.

a. RefertoChapter11, for detailing practices.

b. Providenecessaryandadequateinformationtoensurethecontractplansareaccurate,complete, and readable.

c. Detailplansheetsinaconsistentmannerandfollowaccepteddetailingpractices.

d. Check plans for geometry, reinforcing steel congestion, consistency, and verify control dimensions.

e. Check for proper grammar and spelling.


WSDOT Bridge Design Manual M 23-50.11 Page 1.3-5 March 2012

f. On multiple bridge contracts, work with the Designer/Project Coordinator to ensure that the structural detailing of all bridges within the contract shall be coordinated to maximize consistency of detailing from bridge to bridge. Extra effort will be required to ensure uniformity of details, particularly if multiple design units and/or consultants are involved in preparing bridge plans.

g. Maintain an ongoing understanding of bridge construction techniques and practices.

5. Specialist Responsibility – All bridge and wall projects initiated with a signed Bridge Preliminary Plan.

The primary responsibility of the specialist is to act as a knowledge resource for the Bridge and Structures Office, WSDOT, other governmental agencies and consultants. Designers are encouraged to consult specialists for complex projects early in the design process. Supervisors overseeing a design project should actively identify any complex or unusual features, early in the design process, and encourage the designers involved to seek input from the suitable Specialist. The Specialists maintain an active knowledge of their specialty area, along with a current file of products and design procedures. The Specialists maintain industry contacts. Specialists provide training in their area of expertise.

Specialists are expected to remain engaged with the design efforts being carried out in the office related to their specialty. At the discretion of the Design Unit Supervisor, the Specialists may be requested to review, comment on and initial plans in their area of expertise prepared by other designers. Specialists are expected to review selected design work for consistency with other WSDOT projects, and for adherence to current office practice and current industry practice. Specialist reviews are typically cursory in nature, and are not intended to fulfill the role of structural checker. Specialists shall initial the Project Turn-In QA/QC Worksheet of BDM Appendix 1.5-A3 at the 100% completion stage of certain projects including:

a. Bearing and Expansion Joint Specialist – All expansion joint or bearing rehab projects. All new bridges with modular expansion joints, unique strip seal joints (high skew, raised steel sliding plates at sidewalk, traffic islands, etc.), and bearings other than plain elastomeric pads.

b. Concrete Specialist – All post-tensioned super and substructures, and complex prestressed girder superstructures (long spans, large skews, tapered girders, etc.). All structures utilizing mass concrete, self-consolidating concrete (SCC), shotcrete or Grade 80 reinforcement.

c. Steel Specialist – All new and retrofit steel superstructure projects, or projects involving significant or complex welding.

d. Seismic Specialist – All retrofit projects, and new bridges with complex seismic design requirements.

Specialists assist the Bridge and Structures Engineer in reviewing and voting on amendments to AASHTO specifications.

Specialists are responsible for keeping their respective chapters of the Bridge Design Manual M 23-50 up to date.

The Concrete, Steel, and Seismic Specialists act as Supervisors for the Structural Detailers within their unit. They are responsible for the day-to-day supervision of the Structural Detailers, including timesheet and evaluation responsibilities. The Specialists are also relied upon to assist the Design Unit Supervisor in allocating detailing staff, and completing Structural Detailer staffing projections.



A secondary responsibility of the Specialist is to serve as Unit Supervisor when the supervisor is absent.

Sign Structure design, Wall design, and Traffic Barrier & Rail design are three specialty areas where design and review work has traditionally been directed to dedicated staff in each of the three main design groups within the Bridge Design Office (see BDM 1.2.3). Design guidance or review requests for unusual or unique projects involving these three specialty areas should be directed to the applicable Design Unit Supervisor for design or review.

6. Specification and Estimating Engineer Responsibilities – There are currently four specialist positions in the Bridge and Structures Office. The four specialty areas in the Design Section are bearings and expansion joints, concrete (including prestressed concrete), seismic design and retrofit, and structural steel.

7. Design Unit Supervisor Responsibility

a. The Unit Supervisor is responsible to the Bridge Design Engineer for the timely completion and quality of the bridge plans.

b. The Unit Supervisor works closely with the Project Coordinator and the design team (designer, checker, and structural detailer) during the design and plan preparation phases to help avoid major changes late in the design process. Activities during the course of design include:

(1) Evaluate the complexity of the project and the designer’s skill and classification level to deliver the project in a timely manner. Determine both the degree of supervision necessary for the designer and the amount of checking required by the checker.

(2) Assist the design team in defining the scope of work, identifying the tasks to be accomplished and developing a project work plan.

(3) Make suitable staffing assignments and develop a design team time estimate to ensure that the project can be completed on time and within budget.

(4) Review and approve design criteria before start of design.

(5) Help lead designer conduct face-to-face project meetings, such as: project “kick-off” and “wrap-up” meetings with Region, geotechnical staff, bridge construction, and consultants to resolve outstanding issues.

(6) Participate in coordinating, scheduling, and communicating with stakeholders, customers, and outside agencies relating to major structural design issues.

(7) Facilitate resolution of major project design issues.

(8) Assist the design team with planning, anticipating possible problems, collectively identifying solutions, and facilitating timely delivery of needed information, such as geometrics, hydraulics, foundation information, etc.

(9) Interact with design team regularly to discuss progress, problems, schedule and budget, analysis techniques, constructability and design issues. Always encourage forward thinking, innovative ideas and suggestions for quality improvement.

(10) Arrange for and provide the necessary resources, time and tools for the design team to do the job right the first time. Offer assistance to help resolve questions or problems.

(11) Help document and disseminate information on special features and lessons learned for the benefit of others and future projects.

(12) Mentor and train designers and detailers through the assignment of a variety of structure types.



c. TheUnitSupervisorworkscloselywiththedesignteamduringtheplanreviewphase.Revieweffortsshouldconcentrateonreviewingthecompletedplandetailsanddesigncalculationsforcompletenessandforagreementwithofficecriteriaandofficepractices.Reviewthefollowingperiodicallyandattheendoftheproject:

(1) DesignCriteria• Seismicdesignmethodology,accelerationcoefficient(“a”value),andanyseismic

analysis assumptions.• Foundationreportrecommendations,selectionofalternates.• DeviationsfromAASHTO,thismanual,andproperconsiderationofanyapplicableDesignMemorandums.

(2) DesignTimeandBudget

d. Estimatetimetocompletetheproject.PlanresourceallocationforcompletingtheprojecttomeetthescheduledAdDateandbudget.Monitormonthlytimespentontheproject.

Attheendofeachmonth,estimatetimeremainingtocompleteproject,percentcompleted,andwhetherprojectisonorbehindschedule.

Planandassignworkforcetoensureatimelydeliveryoftheprojectwithintheestimatedtimeandbudget.Atmonthlysupervisors’schedulingmeetings,notifytheBridgeProjectsEngineerifaprojectisbehindschedule.

e. AdviseRegionofanyprojectscopecreepandconstructioncostincreases.Asaminimum,usequarterlystatusreportstoupdateRegiononprojectprogress.

f. Use appropriate computer scheduling software or other means to monitor time usage, toallocateresources,andtoplanprojects.

g. Reviewconstructabilityissues.Arethereanyproblemsuniquetotheproject?

h. Reviewthefinalplansforthefollowing:

(1) Scanthejobfileforunusualitemsrelatingtogeometrics,hydraulics,geotechnical,environmental, etc.

(2) Overallreviewofsheet#1,thebridgelayoutfor:• Consistency—especiallyformultiplebridgeproject• Missinginformation

(3) ReviewfootinglayoutforconformancetoBridgePlanandforadequacyofinformationgiven.Generally,thefieldpersonnelshallbegivenenoughinformationto“layout”thefootingsinthefieldwithoutreferringtoanyothersheets.Plandetailsshallbeclear,precise,anddimensionstiedtobasereferences,suchas:asurveylineordefinedcenterline of bridge.

(4) Reviewthesequenceoftheplansheets. Theplansheetsshouldadheretothefollowingorder: layout, footing layout, substructures, superstructures, miscellaneous details, barriers, and barlist. Also check for appropriateness of the titles.

(5) Reviewoveralldimensionsandelevations,spotcheckforcompatibility.Forexample,checkcompatibilitybetweensuperstructuresandsubstructure.Also spot check bar marks.

(6) Usecommonsenseandexperiencetoreviewstructuraldimensionsandreinforcementforstructuraladequacy.Whenindoubt,questionthedesignerandchecker.

i. Stampandsigntheplansinblueink.



8. Bridge Design Engineer’s Responsibilities – TheBridgeDesignEngineeristhecoach,mentor,andfacilitatorfortheWSDOTQC/QABridgeDesignProcedure.TheleadershipandsupportprovidedbythispositionisamajorinfluenceinassuringbridgedesignqualityforstructuraldesignsperformedbybothWSDOTandconsultants.ThefollowingsummarizesthekeyresponsibilitiesoftheBridgeDesignEngineerrelatedtoQC/QA:

a. PriortotheBridgeDesignEngineerstampingandsigninganyplans,he/sheshallperformastructural/constructabilityreviewoftheplans.Thisisaqualityassurance(QA)functionaswellasmeetingthe“responsiblecharge”requirementsofstatelawsrelatingtoProfessionalEngineers.

b. ReviewandapprovethePreliminaryBridgePlans.Theprimaryfocusforthisresponsibilityis to assure that the most cost-effective and appropriate structure type is selected for a particular bridge site.

c. ReviewuniqueprojectspecialprovisionsandStandardSpecificationmodificationsrelatingto structures.

d. FacilitatepartnershipsbetweenWSDOT,consultants,andtheconstructionindustrystakeholders to facilitate and improve design quality.

e. Encouragedesignercreativityandinnovationthroughforwardthinking.

f. ExerciseleadershipanddirectionformaintainingaprogressiveanduptodateBridge Design Manual M 23-50.

g. CreateanopenandsupportiveofficeenvironmentinwhichDesignSectionstaffareempowered to do high quality structural design work.

h. Createprofessionalgrowthopportunitiesthroughanofficeculturewherelearningisemphasized.

i. Encouragecontinuingprofessionaldevelopmentthroughtrainingopportunities,attendanceat seminars and conferences, formal education opportunities, and technical writing.

9. General Bridge Plan Stamping and Signature Policy – The stamping and signing of bridge plansisthefinalstepintheBridgeQC/QAprocedure.Itsignifiesareviewoftheplansanddetailsbythoseinresponsiblechargeforthebridgeplans.AtleastoneLicensedStructuralEngineershallstampandsigneachcontractplansheet(exceptthebarlist).

ForcontractplanspreparedbyalicensedCivilorLicensedStructuralEngineer,theUnitManagerandthelicensedCivilorLicensedStructuralEngineerco‑sealandsigntheplans,exceptthebridgelayoutsheet.ThebridgelayoutsheetissealedandsignedbytheStateBridgeandStructuresEngineeror,intheabsenceoftheStateBridgeandStructuresEngineer,theBridgeDesignEngineer.

ForcontractplansnotpreparedbyalicensedCivilorLicensedStructuralEngineer,theUnitManagerandtheBridgeDesignEngineerco‑sealandsigntheplansexceptthebridgelayoutsheet.ThebridgelayoutsheetissealedandsignedbytheStateBridgeandStructuresEngineeror,intheabsenceoftheStateBridgeandStructuresEngineer,theBridgeDesignEngineer.

ForNon‑StandardRetainingWallsandNoiseBarrierWalls,SignStructures,SeismicRetrofits,ExpansionJointandBearingModifications,TrafficBarrierandRailRetrofits,andotherspecialprojects,theUnitManagerwitheitherthelicenseddesignerortheBridgeDesignEngineer(ifthedesignerisnotlicensed)co‑sealandsigntheplansexceptforthelayoutsheet.ThelayoutsheetsfortheseplansaresealedandsignedbytheStateBridgeandStructuresEngineer,orintheabsenceoftheStateBridgeandStructuresEngineer,theBridgeDesignEngineer.





B. Consultant PS&E — Projects on WSDOT Right of Way – PS&EpreparedbyconsultantswillfollowasimilarQC/QAprocedureasthatshownaboveforWSDOTpreparedPS&E’sand,asaminimum, shall include the following elements:

1. WSDOT Consultant Liaison Engineer’s Responsibilities

a. Reviewscopeofwork.

b. Negotiatecontractandconsultant’sTaskAssignments.

c. Coordinate/NegotiateChangestoScopeofWork.

2. Bridge Scheduling Engineer Responsibilities

a. Add review to the bridge schedule.

b. Assign review to a bridge unit supervisor.

c. Make2copiesofthereviewplansandspecifications–1forthedesignreviewerand1fortheSpecificationsEngineerReviewer

d. MakeacopyoftheLayoutfortheBridgeInventoryEngineer.

3. WSDOT Design Reviewer’s or Coordinator’s Responsibilities

a. Earlyintheproject,reviewconsultant’sdesigncriteria,andstandarddetailsforconsistencywithWSDOTpracticesandotherbridgedesignsinproject.

b. ReviewthejobfileaspreparedbythePreliminaryPlanEngineer.

c. Identify resources needed to complete work.

d. Initiateaprojectstart‑upmeetingwiththeConsultanttodiscussdesigncriteria,submittalscheduleandexpectations,andalsotofamiliarizehimself/herselfwiththeConsultant’sdesigners.

e. Reachagreementearlyinthedesignprocessregardingstructuralconceptsanddesignmethods to be used.

f. Identifywhoisresponsibleforwhatandwhenallintermediateconstructability,BridgePlans,andBridgePS&Ereviewsubmittalsaretobemade.

g. Monitor progress.

h. Facilitatecommunication,includingface‑to‑facemeetings.

i. VerifythattheConsultant’sdesignhasbeencheckedbytheConsultant’scheckeratthe100%submittal.Thechecker’scalculationsshouldbeincludedinthedesigner’scalculationset.

j. Reviewconsultant’sdesigncalculationsandplansforcompletenessandconformancetoBridgeOfficedesignpractice.Theplansshallbecheckedforconstructability,consistency,clarity and compliance. Also, selectively check dimensions and elevations.

k. Resolvedifferences.

4. WSDOT Design Unit Supervisor’s Responsibilities

a. Encourageandfacilitatecommunication.

b. Earlyinvolvementtoassurethatdesignconceptsareappropriate.

c. EmpowerDesignReviewerorCoordinator.

d. FacilitateresolutionofissuesbeyondauthorityofWSDOTReviewerorCoordinator.

e. Facilitateface‑to‑facemeetings.



5. WSDOT S&E Engineer’s Responsibilities – SeeSection12.4.8.

6. WSDOT Bridge Design Engineer’s Responsibilities

a. Cursory review of design plans.

b. SignatureapprovalofS&Ebridgecontractpackage.

C. Consultant PS&E—ProjectsonCountyandCityRightofWay

CountiesandcitiesfrequentlyhireConsultantstodesignbridges.WSDOTHighwaysandLocalProgramsOfficedeterminewhichprojectsaretobereviewedbytheBridgeandStructuresOffice.

WSDOTHighwaysandLocalProgramssendthePS&EtotheBridgeProjectsEngineerforassignmentwhenareviewisrequired.TheBridgeandStructuresOffice’sConsultantLiaisonEngineerisnotinvolved.

AWSDOTDesignReviewerorCoordinatorwillbeassignedtotheprojectandwillreviewtheprojectasoutlinedforConsultantPS&E—ProjectsonWSDOTRightofWay(seeSection1.3.2.B).

Twosetsofplanswiththereviewers’commentsmarkedinredshouldbereturnedtotheBridgeProjectsUnit.OnesetofplanswillbereturnedtoHighwaysandLocalPrograms.TheBridgeSchedulingEngineerwillfiletheothersetintheBridgeProjectsUnit.

ThefirstreviewshouldbemadeofthePreliminaryPlanfollowedlaterbyreviewofthePS&Eanddesigncalculations.Commentsaretreatedasadvisory,althoughmajorstructuralissuesmustbe addressed and corrected. An engineer from the county, city, or consultant may contact the reviewer to discuss the comments.

1.3.3 Design/Check Calculation FileA. File of Calculations – TheBridgeandStructuresOfficemaintainsafileofallpertinentdesign/

checkcalculationsfordocumentationandfuturereference.(SeeSection1.3.8ArchivingDesignCalculations,DesignFiles,andS&EFiles).

B. Procedures – Afteranassignedprojectiscompletedandthebridgeisbuilt,thedesignershallturninaboundfilecontainingthedesign/checkcalculationsforarchiving.Thefrontcovershouldhavealabel(SeeFigure1.3.8‑1).

C. File Inclusions – Thefollowingitemsshouldbeincludedinthefile:

1. Index Sheets – Numberallcalculationsheetsandprepareanindexbysubjectwiththecorresponding sheet numbers.

Listthenameoftheproject,SRNumber,designer/checkerinitials,date(month,day,andyear),andUnitSupervisor’sinitials.

2. Design Calculations – The design calculations should include design criteria, design assumptions, loadings, structural analysis, one set of moment and shear diagrams and pertinent computerinputandoutputdata(reducedto8½″by11″sheetsize).

The design criteria, design assumptions, and special design features should follow in that order behindtheindex.

Computer-generated design calculations may be used instead of longhand calculations. The calculationsheetsshallbeformattedsimilartoWSDOTstandardcalculationsheets(WSDOTForm232‑007)forlonghanddesigns.TheheaderforelectroniccalculationsheetsshallcarryWSDOTlogoalongwithprojectname,S.R. number,designerandchecker’sname,date,supervising engineer, and sheet numbers.

All computer-generated or longhand design calculations shall be initialed by the designer and checker.Checker’sinitialmaynotbenecessaryifseparatecheckcalculationsareprovided.



OutputfromcommercialsoftwareshallbeintegratedintodesigncalculationswithacoversheetthatincludestheWSDOTlogoalongwithprojectname,S.R.number,designerandchecker'sname, date, supervising engineer, and sheet numbers.

Consultant submitted design calculations shall comply with the above requirements.

DesigncalculationspreparedbytheBridgeDesignOfficeorConsultantsneednotbesealedandsigned.Designcalculationsareconsideredpartoftheprocessthatdevelopscontractplanswhicharethefinaldocuments.

SeeAppendix1.5‑A4‑1forexamplesofExceltemplateforcomputer‑generateddesigncalculations.Codeandotherreferencesusedindevelopingcalculationsshallbespecified.Ingeneral,whenusingExcelspreadsheet,enoughinformationandequationsshallbeprovided/shown in the spreadsheet so that an independent checker can follow the calculations.

3. Special Design Features – Briefnarrativeofmajordesigndecisionsorrevisionsandthereasonsfor them.

4. Construction Problems or Revisions – Not all construction problems can be anticipated during the design of the structure; therefore, construction problems arise during construction, which will require revisions. Calculations for revisions made during construction should be included in the design/checkcalculationfilewhenconstructioniscompleted.

D. File Exclusions – Thefollowingitemsshouldnotbeincludedinthefile:

1. Geometriccalculations.

2. Irrelevant computer information.

3. PrintsofOfficeStandardSheets.

4. Irrelevantsketches.

5. Voided sheets.

6. Preliminarydesigncalculationsanddrawingsunlessusedinthefinaldesign.

7. Test hole logs.

8. Quantitycalculations.

1.3.4 PS&E Review PeriodSeeSection12.4.10forPS&EReviewPeriodandTurn‑inforADCopyactivities.

1.3.5 AddendaPlanorspecificationrevisionsduringtheadvertisingperiodrequireanaddendum.TheSpecificationsandEstimateEngineerwillevaluatetheneedfortheaddendumafterconsultationwiththeHQConstruction— Bridge,Region,andtheHQorRegionPlansBranch.TheBridgeDesignEngineerortheUnitSupervisormustinitialalladdenda.

Foraddendatocontractplans,obtaintheoriginaldrawingfromtheBridgeProjectsUnit.Useshadingtomarkallchanges(exceptdeletions)andplacearevisionnoteatthebottomofthesheet(RegionandHQPlansBranchjointlydetermineaddendumdate)andadescriptionofthechange.Returnthe11″by17″signedoriginalandcopytotheSpecificationsandEstimateEngineerwhowillsubmitthecopytotheHQPlansBranchforprocessing.SeeChapter12 for additional information.

Forchangestospecifications,submitacopyofthepagewiththechangetotheSpecificationsandEstimateEngineerforprocessing.



1.3.6 Shop Plans and Permanent Structure Construction ProceduresThis section pertains to fabrication shop plans, weld procedures, electrical and mechanical items, geotechnical procedures, such as: drilled shafts and tieback walls, and other miscellaneous items related to permanent construction.

The following is a guide for checking shop plans and permanent structure construction procedures.

A. Bridge Shop Plans and Procedures

1. Markonecopyofeachsheetwiththefollowing,nearthetitleblock,inredpenorwitharubberstamp:

OfficeCopy Contract(number) (Checker’sinitials)(Date) ApprovalStatus(A,AAN,RFCorStructurallyAcceptable)

2. OntheBridgeOfficecopy,markwithredpenanyerrorsorcorrections.Yellowshallbeusedfor highlighting the checked items. The red pen marks will be copied onto the other copies and returnedtotheRegionProjectEngineer.Commentsmadewithredpen,especiallyfor8½″by11″or11″by17″sizesheets,shallbeclear,neat,andconducivetobeingreproducedbyXerox.Thesecommentsshouldbe“bubbled”sotheystandoutonablackandwhiteXeroxcopy.Useoflargesheetsshouldbediscouragedbecausetheserequireextrastaffassistanceandtimetomakethesecopies by hand.

3. Itemstobecheckedaretypicallyasfollows:CheckagainstContractPlansandAddenda,SpecialProvisions,PreviouslyApprovedChangesandStandardSpecifications.

a. Materialspecifications(ASTMspecifications,hardness,alloyandtemper,etc.).

b. Sizeofmemberandfasteners.

c. Lengthdimensions,ifshownontheContractPlans.

d. Finish(surfacefinish,galvanizing,anodizing,painting,etc.).

e. Weldsizeandtypeandweldingprocedureifrequired.

f. Strandorrebarplacement,jackingprocedure,stresscalculations,elongations,etc.

g. Fabrication—reaming,drilling,andassemblyprocedures.

h. Adequacy of details.

i. Erectionprocedures.

Forprestressedgirdersandpost‑tensioningshopplanreviewseeSections5.6.3A and 5.8.6Crespectively.

4. ItemsNotRequiringCheck

a. Quantities in bill of materials.

b. LengthdimensionsnotshownonContractPlansexceptforspotcheckingandisemphasizedby stamping the plans: Geometry Not Reviewed by the Bridge and Structures Office.

5. ProjectEngineer’sCopy

DonotusetheProjectEngineer’scopy(commentsorcorrectionsareingreen)astheofficecopy.TransfertheProjectEngineer’scorrections,ifpertinent,totheofficecopyusingredpen.TheProjectEngineer’scommentsmayalsobereceivedbye‑mail.



6. MarkingCopies

Whenfinished,marktheofficecopywithoneoffivecategoriesinredpen,lowerrightcorner.

a. “A”

Approved, No Corrections required.

b. “AAN”

ApprovedAsNoted—minorcorrectionsonly.Donotplacewrittenquestionsonanapproved as noted sheet.

c. “RFC”

ReturnedforCorrection—majorcorrectionsarerequiredwhichrequiresacompleteresubmittal.

d. “StructurallyAcceptable”

Thisisappropriateforitemsthatarenotrequiredtobe“Approved”perthecontract,suchas:work platforms, submittals from various local agencies or developers, and other items that are reviewed as a courtesy.

e. “StructurallyAcceptableButDoesNotConformtotheContractRequirements”

This is appropriate when a deviation from the contract is found but is determined to be structurally acceptable.

IfindoubtbetweenAANandRFC,checkwiththeUnitSupervisororConstructionSupportEngineer.Anacceptabledetailmaybeshowninred.MarktheplansApproved As Noted provided that the detail is clearly noted Suggested Correction — Otherwise Revise and Resubmit.

Donotmarktheothercopies.TheConstructionSupportUnitwilldothis.

NotifytheConstructionSupportEngineerifthereareanystructurallyacceptabledeviationstothecontractplans.TheConstructionSupportEngineerwillnotifyboththeRegionProjectEngineerandHQConstruction‑Bridge,whomayhavetoapproveachangeorderandprovidejustificationfor the change order.

NotifytheUnitSupervisorandtheConstructionSupportEngineerifproblemsareencounteredwhich may cause a delay in the checking of the shop plans or completion of the contract. Typically,WSDOTadministeredcontractsrequirereviewstobecompletedwithin30days.ThereviewtimestartswhentheProjectEngineerfirstreceivesthesubmittalfromtheContractorandendswhentheContractorhasreceivedthesubmittalbackfromtheProjectEngineer.TheBridgeOfficedoesnothavetheentire30‑dayreviewperiodtocompletethereview.Therefore,designersshould give construction reviews high priority and complete reviews in a timely manner so costly construction delays are avoided. Time is also required for marking, mailing and other processing. ItisthegoaloftheBridgeandStructuresOfficetoreturnreviewedsubmittalsbacktotheProjectEngineerwithin7to14daysoftheirreceiptbytheBridgeConstructionSupportUnit.

ReturnallshopdrawingsandContractPlanstotheConstructionSupportUnitwhencheckingiscompleted.IncludealistofanydeviationsfromtheContractPlansthatareallowedandalistofanydisagreementswiththeProjectEngineer’scomments(regardlessofhowminortheymaybe).

IfdeviationsfromtheContractPlansaretobeallowed,aChangeOrdermayberequired.AlerttheConstructionSupportUnitsothattheirtransmittallettermayinformtheRegionandtheHQConstruction‑Bridge.

Under no circumstances should the reviewer mark on the shop plans that a change order isrequiredornotifytheProjectEngineerthatachangeorderisrequired.TheauthorityfordeterminingwhetherachangeorderisrequiredrestswithHQConstruction‑Bridge.



B. Sign Structure, Signal, and Illumination Shop Plans – In addition to the instructions described under Section1.3.6ABridgeShopPlansandProcedures, the following instructions apply:

1. ReviewtheshopplanstoensurethatthepolesizesconformtotheContractPlans.Determineifthe fabricator has supplied plans for each pole or type of pole called for in the contract.

2. TheProjectEngineer’scopymayshow shaftlengthswherenotshownonContractPlansorwhetherachangefromContractPlansisrequired.Manufacturer’sdetailsmayvaryslightlyfromcontract plan requirements, but must be structurally adequate to be acceptable.

C. Geotechnical Submittals – TheBridgeOfficeandtheGeotechnicalServicesBranchconcurrentlyreview these submittals which may include special design proprietary retaining walls, drilled shafts, groundanchors,andsoldierpiles.HQConstructionOffice‑Bridgeisincludedforthereviewofdrillshaftinstallationplans.TheConstructionSupportUnitcombinesthesecommentsandpreparesaunifiedreplythatisreturnedtotheProjectEngineer

1.3.7 Contract Plan Changes (Change Orders and As-Builts)A. Request for Changes – The following is intended as a guide for processing changes to the design

plansafteraprojecthasbeenawarded.

ForprojectswhichhavebeenassignedaBridgeTechnicalAdvisor(BTA),structuraldesignchangeorderscanbeapprovedattheProjectEngineer’slevelprovidedtheinstructionsoutlinedintheConstruction Manual M41‑01arefollowed.

Forallotherprojects,allchangesaretobeforwardedthroughtheConstructionSupportUnit,whichwillinformtheHQConstructionEngineer‑Bridge.Responsestoinquiriesshouldbehandledasfollows:

1. Request by Contractor or Supplier – Adesigner,BTA,orUnitSupervisorcontacteddirectlybya contractor/supplier may discuss a proposed change with the contractor/supplier, but shall clearly tellthecontractor/suppliertoformallysubmittheproposedchangethoughtheProjectEngineerandthatthediscussioninnowayimpliesapprovaloftheproposedchange.DesignersaretoinformtheirUnitSupervisoriftheyarecontacted.

2. Request From the Region Project Engineer – RequestsforchangesdirectlyfromtheProjectEngineertodesignerortheUnitSupervisorshouldbediscouraged.TheProjectEngineershouldcontactHQConstruction‑Bridge,whointurnwillcontactthedesignerorUnitSupervisorifclarificationisneededregardingchanges.TheConstructionSupportUnitshouldbeinformedofany changes.

3. Request From the Region Construction Engineer – RequestsfromtheRegionConstructionEngineeraretobehandledlikerequestsfromtheRegionProjectEngineer.

4. Request From the HQ Construction - Bridge – RequestsforchangesfromHQConstruction‑BridgeareusuallymadethroughtheConstructionSupportUnitandnotdirectlytotheDesignUnit.However,sometimes,itisnecessarytoworkdirectlywiththeDesignUnit.TheConstructionSupportUnitshouldbeinformedofanydecisionsmadeinvolvingchangestotheContractPlans.

5. Request From the Design Unit – RequestforchangesfromtheDesignUnitduetoplanerrorsoromissionsshallbediscussedwiththeBridgeDesignEngineerpriortorevisingandissuingnewplan sheets.

B. Processing Contract Revisions – ChangestotheContractPlansorSpecificationssubsequenttotheawardofthecontractmayrequireacontractplanrevision.Revisedoradditionalplansheets,whichclearlyidentifythechangeontheplans,maybeneeded.Whenarevisionoranadditionaldrawingisnecessary,requesttheoriginalplansheetsfromtheConstructionSupportUnit’sBridgePlansEngineerandpreparerevisedorneworiginalplansheets.




Sign,date,andsendthenewplansheetstotheBridgePlansEngineer.SendtwopapercopiestoHQConstruction‑Bridge.TheConstructionSupportUnitrequiresonepapercopy.TheDesignUnitrequiresoneormorepapercopies.Onepaperprint,stamped“As Constructed Plans”, shall be sent totheProjectEngineer,whoshalluseittomarkconstructionchangesandforwardthemas“As-Built Plans”totheBridgePlansEngineeruponprojectcompletion.TheDesignerisresponsibleformakingthe prints and distributing them.

ThisprocessappliestoallcontractsincludingHQAdandAward,RegionAdandAward,orLocalAgency Ad and Award.

Whenevernewplansheetsarerequiredaspartofacontractrevision,theinformationinthetitleblocksofthesesheetsmustbeidenticaltothetitleblocksofthecontracttheyarefor(e.g.,JobNumber,ContractNo.,Fed.AidProj.No.,Approvedby,andtheProjectName).ThesetitleblocksshallalsobeinitialedbytheBridgeDesignEngineer,UnitSupervisor,designer,andreviewerbeforetheyaredistributed.Ifthechangesaremodificationsmadetoanexistingsheet,thesheetnumberwillremain the same. A new sheet shall be assigned the same number as the one in the originals that it mostcloselyresemblesandshallbegivenaletterafterthenumber(e.g.,ifthenewsheetappliestotheoriginalsheet25of53,thenitwillhavenumber25Aof53).TheBridgePlansEngineerintheConstructionSupportUnitshallstorethe11″by17″originalrevisionsheets.

Everyrevisionwillbeassignedanumber,whichshallbeenclosedinsideatriangle.Theassignednumber shall be located both at the location of the change on the sheet and in the revision block of the plansheetalongwithanexplanationofthechange.

AnyrevisedsheetsshallbesenttoHQConstruction‑Bridgewithawrittenexplanationdescribingthechangestothecontract,justificationforthechanges,andalistofmaterialquantityadditionsordeletions.

C. As-Built Plan Process – Formoreinformationontheas‑builtplanprocessforbridges,seetheAs-Built Plans Manual,preparedbytheBridgeandStructuresOffice,datedAugust2003.CopiesareavailablefromtheBridgePlansEngineer.

1.3.8 Archiving Design Calculations, Design Files, and S&E FilesA. Upon Award – TheBridgePlansEngineerwillcollecttheDesignFile(JobFile),S&EFileand

DesignCalculations.Fileswillbeplacedinatemporarystoragespacemarkedas“DesignUnitDocumentTemporaryStorage”.Thesecabinetswillbelocked,andonlytheBridgePlansEngineer,theSchedulingEngineer,andtheOfficeAdministratorwillhavekeystothem.TheDesignFiles,S&EFiles,andDesignCalculationsarestoredunderthecontractnumber.

ABridgeandStructuresstaffmembermayaccesstheDesignFiles,S&EFiles,orDesignCalculationsbyrequestingthefilesfromtheBridgePlansEngineerortheSchedulingEngineer,whowillcheckoutthefilesandnotethedateandperson’sname.IfapersonotherthanaBridgeandStructuresOfficestaffmemberrequeststhesedocuments,theapprovaloftheBridgeDesignEngineerorBridgeProjectsEngineerwillberequiredforreleaseofthedocuments.

B. Upon Contract Completion – Thedesignerwillplaceajobfilecoverlabelonthefilefolder(seeFigure1‑3.8‑1)andupdatethefilewithanycontractplanchangesthathaveoccurredduringconstruction.

Twoyearsafterphysicalcompletionofthecontract,theBridgePlansEngineerwillboxandsendthedocumentstotheOfficeofSecretaryofStateforarchivestorage,exceptasotherwiseapprovedbytheBridgeDesignEngineer.

TheBridgePlansEngineerwillmaintainarecordofthedocumentslocationandarchivestatus.



SR # County CS # Bridge Name Bridge # Contract # Contents Designed by Checked by Archive Box # Vol. #

Cover LabelFigure 1.3.8-1

1.3.9 Public Disclosure Policy Regarding Bridge PlansTheBridgeManagementEngineeristheBridgeandStructuresOffice’sofficialPublicDisclosurecontactandshallbecontactedforclarificationand/ordirection.

ExecutiveOrder,E1023.0 Public Disclosure,whichreplacedDirectiveD72‑21 Release of Public Records,providesaspecificproceduretofollowwhenthereisarequestforpublicrecords. (Seewwwi.wsdot.wa.gov/Publications/Policies/default.htm.)

TheBridgeandStructuresOfficeisthe“owner”ofonlytwotypesof“official”records:(1)DesignCalculations (untiltheyareturnedovertotheStateArchivesOffice)and(2)BridgeInspectionDocuments.

Norecordswillbedisclosedwithoutawrittenrequest.Thisrequestistobespecific.

As‑builtplansavailableontheBridgeandStructureswebsitearenot“official”as‑builtplans.TheRegionsaretheownersofthe“official”as‑builtplansandtheprocedureforprovidingrequestedcopiesoftheseplansissimilartotheprocedureoutlinedabovewiththefollowingmodifications:• IfyoureceiveawrittenorverbalrequestforasetofplansfromapersonindirectlyworkingforWSDOT(i.e.contractor,consultant),advisethemtocontactandrequesttheplansfromtheWSDOTProjectEngineer.

• IftherequestcomesfromapersondirectlyworkingonaBridgeOfficeprojectasanon‑callconsultant,havethemcontactandrequesttheplansfromtheBridgeandStructuresOffice’sConsultantLiaisonEngineer.

• IftherequestcomesfromapersonnotworkingforWSDOT,theymustsubmittheirwrittenrequesttothepersonandaddressnotedbelowanditwillbeforwardedtotheappropriateRegiontoprovidethe requested documents.

Writtenrequestsmustbesentto: RecordsandInformationServiceOffice WashingtonStateDepartmentofTransportation 310MapleParkAvenue P.O.Box47410 Olympia,WA98504‑7410 Attn:Ms.CathyDowns

http://wwwi.wsdot.wa.gov/Publications/Policies/default.htm



1.3.10 Use of Computer SoftwareA. Protection of Intellectual Property – ManyofthesoftwaretoolsusedbytheBridgeandStructures

Officearelicensedfromcommercialsoftwarevendors.WSDOTiscommittedtousingthesetoolsonlyasallowedbylawandaspermittedbysoftwarelicense.WSDOTemployeesshallcomplywiththe terms and conditions of all licensing agreements and provisions of the Copyright Act and other applicable laws.

BeforeusinganysoftwaretoolsWSDOTemployeesshallreadandunderstandInstructionalLetter4032.00Computer Software Piracy Prevention, and the Protection of Intellectual Property.1

B. Policy on Open Source Software – ItisthepolicyoftheBridgeandStructuresOfficetolicenseitsown engineering software as open source, and to prefer and promote the use of open source software, within the bridge engineering community.

Tosupportthispolicyonopensourcebridgeengineeringsoftware,theBridgeandStructuresOfficeisafoundingandparticipatingmemberoftheAlternateRouteProject.ThepurposeoftheAlternateRouteProjectistoserveasafocalpointforthecollaborativeandcooperativedevelopmentofopensource bridge engineering software tools.

C. Approved Software Tools – AlistofapprovedsoftwaretoolsavailableforusebyWSDOTbridgedesign engineers is available at wwwi.wsdot.wa.gov/eesc/bridge/software. Note that this list is only availableontheWSDOTintranet.WSDOTdoesnotrequireconsultingengineerstouseanyspecificsoftware tools, so long as the use of the tools are in accordance with sound engineering practice, and does not violate software licensing agreements and Copyright law.

Whenusingpersonaldesigntoolscreatedbyothers,suchasaspreadsheetorMathCADdocument,the designer is responsible for thoroughly checking the tool to ensure the integrity of the structural analysis and design.

wwwi.wsdot.wa.gov/eesc/bridge/software



WSDOT Bridge Design Manual M 23-50.11 Page 1.5-A3-1 March 2012

Appendix 1.5-A3 QA/QC Signature Sheet


Page 1.5-A3-2 WSDOT Bridge Design Manual M 23-50.11 March 2012

WSDOT Bridge Design Manual M 23-50.11 Page 4-i March 2012

Chapter 4 Seismic Design and Retrofit Contents4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1-1

4.2 WSDOT Modifications to AASHTO Guide Specifications for LRFD Seismic Bridge Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14.2.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14.2.2 EarthquakeResistingSystems(ERS)RequirementsforSDCsCandD . . . . . . . . 4.2-14.2.3 SeismicGroundShakingHazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.4 SelectionofSeismicDesignCategory(SDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.5 TemporaryandStagedConstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.6 LoadandResistanceFactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-74.2.7 BalancedStiffnessRequirementsandBalancedFrameGeometry

Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.8 SelectionofAnalysisProceduretoDetermineSeismicDemand. . . . . . . . . . . . . . . 4.2-84.2.9 MemberDuctilityRequirementforSDCsCandD . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.10 LongitudinalRestrainers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.11 Abutments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-84.2.12 Foundation–General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.13 Foundation–SpreadFooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.14 Procedure3:NonlinearTimeHistoryMethod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.15 IeffforBoxGirderSuperstructure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.16 FoundationRocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.17 DrilledShafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.18 LongitudinalDirectionRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-94.2.19 LiquefactionDesignRequirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.20 ReinforcingSteel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.21 ConcreteModeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.22 ExpectedNominalMomentCapacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-104.2.23 InterlockingBarSize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.24 SplicingofLongitudinalReinforcementinColumnsSubjecttoDuctility

DemandsforSDCsCandD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.25 DevelopmentLengthforColumnBarsExtendedintoOversizedPileShafts

forSDCsCandD. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.26 LateralConfinementforOversizedPileShaftforSDCsCandD . . . . . . . . . . . . .4.2-114.2.27 LateralConfinementforNon‑OversizedStrengthenedPileShafforSDCsC

andD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.28 RequirementsforCapacityProtectedMembers. . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-114.2.29 SuperstructureCapacityDesignforTransverseDirection(IntegralBentCap)

forSDCsCandD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-124.2.30 SuperstructureDesignforNonIntegralBentCapsforSDCsB,C,andD . . . . . . 4.2-124.2.31 JointProportioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-124.2.32 Cast‑in‑PlaceandPrecastConcretePiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-14

4.3 Seismic Design Requirements for Bridge Widening Projects . . . . . . . . . . . . . . . 4.3-14.3.1 SeismicAnalysisandRetrofitPolicy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3-14.3.2 DesignandDetailingConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3-4

Contents Chapter 4

Page 4-ii WSDOT Bridge Design Manual M 23-50.11 March 2012

4.4 Seismic Retrofitting of Existing Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.1 Seismic Analysis Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.2 Seismic Retrofit Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.3 Computer Analysis Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-14.4.4 Earthquake Restrainers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-24.4.5 Isolation Bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4-2

4.5 Seismic Design Requirements for Retaining Walls . . . . . . . . . . . . . . . . . . . . . . . . 4.5-14.5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5-1

4.99 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.99-1

Appendix 4-B1 Design Examples of Seismic Retrofits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-B1-1Appendix 4-B2 SAP2000 Seismic Analysis Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-B2-1


Chapter 4 Seismic Design and Retrofit

4.1 GeneralSeismicdesignofnewbridgesandbridgewideningsshallconformtoAASHTO Guide Specifications for LRFD Seismic Bridge DesignasmodifiedbySections4.2and4.3.Analysis anddesignofseismicretrofitsforexistingbridgesshallbecompletedinaccordancewithSection4.4.SeismicdesignofretainingwallsshallbeinaccordancewithSection 4.5. Fornonconventionalbridges,bridgesthataredeemedcriticaloressential,orbridgesthatfalloutsidethescopeoftheGuideSpecificationsforanyotherreasons,projectspecificdesignrequirementsshallbedevelopedandsubmittedtotheWSDOTBridgeDesignEngineerforapproval.

TheimportanceclassificationsforallhighwaybridgesinWashingtonStateareclassifiedas“Normal”exceptforspecialmajorbridges.Specialmajorbridgesfittingtheclassificationsofeither“Critical”or“Essential”willbesodesignatedbyeithertheWSDOTBridgeandStructuresEngineerortheWSDOTBridgeDesignEngineer.Theperformanceobjectfor“normal”bridgesislifesafety.BridgesdesignedinaccordancewithAASHTOGuideSpecificationsareintendedtoachievethelifesafetyperformancegoals.

Seismic Design and Retrofit Chapter 4




4.2 WSDOT Modifications to AASHTO Guide Specifications for LRFD Seismic Bridge Design

WSDOTamendmentstotheAASHTO Guide Specifications for LRFD Seismic Bridge Designareasfollows:

4.2.1 Definitions

Guide Specifications Article 2.1–Addthefollowingdefinitions:

• Oversized Pile Shaft – Adrilledshaftfoundationthatislargerindiameterthanthesupportedcolumnandhasareinforcingcagelargerthanandindependentofthecolumns.ThesizeoftheshaftshallbeinaccordancewithSection7.8.2.

• Owner – Personoragencyhavingjurisdictionoverthebridge.ForWSDOTprojects,regardlessofdeliverymethod,theterm“Owner”intheseGuideSpecificationsshallbetheWSDOTBridgeDesignEngineeror/andtheWSDOTGeotechnicalEngineer.

4.2.2 Earthquake Resisting Systems (ERS) Requirements for SDCs C and D

Guide Specifications Article 3.3 – WSDOTGlobalSeismicDesignStrategies:

• Type 1–DuctileSubstructurewithEssentiallyElasticSuperstructure.Thiscategoryispermissible.

• Type 2–EssentiallyElasticSubstructurewithaDuctileSuperstructure.Thiscategoryisnotpermissible.

• Type 3–ElasticSuperstructureandSubstructureWithaFusingMechanismBetweentheTwo.ThiscategoryispermissiblewithWSDOTBridgeDesignEngineer’sapproval.

Type3ERSmaybeconsideredonlyifType1strategyisnotsuitableandType3strategyhasbeendeemednecessaryforaccommodatingseismicloads.IsolationbearingsshallbedesignedpertherequirementoftheAASHTO Guide Specifications for Seismic Isolation. UseofisolationbearingsneedstheapprovalofWSDOTBridgeDesignEngineer.

Thedecisionforusingisolationbearingsshouldbemadeattheearlystageofprojectdevelopmentbasedonthecomplexityofbridgegeotechnicalandstructuraldesign.Acost‑benefitanalysiscomparingType1designvs.Type3designwithisolationbearingsshallbeperformedandsubmittedforapproval.Thedesignerneedstoperformtwoseparatedesigns,onewithandonewithoutseismicisolationbearings.Thecost‑benefitanalysisshallatleastinclude:

• Higherinitialdesigntimeandcomplexityofanalysis.

• Impactoftheinitialandfinaldesigntimeontheprojectdeliveryschedule.

• Timerequiredforpreliminaryinvestigationandcorrespondenceswiththeisolationbearingssuppliers.

• Life‑cyclecostofadditionalandspecializedbearinginspections.

• Potentialcostimpactforbearingsandexpansionjointsreplacements.



• Issuesrelatedtolong‑termperformanceandmaintenance.

• Needforlargemovementexpansionjoints.

Seismicisolationbearings shallnotbeusedbetweenthetopofthecolumnandthebottomofthecrossbeaminsingleormulti‑columnbents.

Onceapprovalhasbeengivenfortheuseofseismicisolationbearing,thedesignershallsendasetofpreliminarydesignandspecificationrequirementstoatleastthreeseismic isolationbearingsuppliersforevaluationtoensurethattheycanmeetthedesignandspecificationrequirements.Commentsfromisolationbearingsuppliersshouldbeincorporatedbeforedesignofstructurebegins.SolesourceisolationbearingsuppliermaybeconsidereduponBridgeDesignOffice,andProjectEngineer'sofficeapproval.

Thedesignershallsubmittotheisolation bearingsuppliersmaintenanceandinspectionrequirementswithdesigncalculations.Isolationbearingsuppliersshallprovidemaintenanceandinspectionrequirementstoensuretheisolatorswillfunctionproperlyduringthedesignlifeandafterseismicevents.Thecontractplansshallincludebearingreplacementmethodsanddetails.

Useofseismicisolationbearingsarenotrecommendedforconventionalshortandmediumlength bridgesorbridgeswithgeometricalcomplexities.Useofisolationbearingsmaynotbebeneficialforconcretebridgesunder700ftlong,steelbridgesunder800ftlong,bridgeswithskewanglesexceeding30degrees,bridgeswithgeometricalcomplexities,variablesuperstructurewidth,andbridgeswithdrop‑inspans.

Theresponsemodificationfactors(R‑factors)oftheAASHTO Guide Specifications for Seismic Isolation DesignArticle6shallnotbeusedforstructuresiftheprovisionsofAASHTO Guide Specifications for LRFD Seismic Bridge Designarebeingfollowedforthedesignofthebridge.

Suitabilityofisolationbearingsfor bridgeprojectsshouldbecarefullystudiedpriortoapproval.Isolationbearingsmaynotbetheeffectivesolutionforsomebridgesandsitessinceshiftingtheperiodtolongerperiodmaynotreducetheforcedemandforthesoft soils.Designshallconsiderthenearfaulteffectsandsoilstructureinteractionofsoft soilsites.Thedesignershallcarefullystudytheeffectofisolationbearingsonthelongitudinalbridgemovement.Theneedforlargemovementexpansionjointsshallbeinvestigated.Inspection,maintenance,andpotentialfuturebearingreplacementshouldbeconsideredwhenusingtheisolationbearings.

Inordertohaveisolatorsfullyeffective,sufficientgapshallbeprovidedtoeliminatepoundingbetweenframes.Recommendedbridgelengthandskewlimitationaresettoavoid usingthemodularjoints.Mostmodularjointsarenotdesignedforseismic.Bridgesaredesignedforextremeeventwhichmayormaynothappeninthelifespanofthebridge.Introducingthemodularjointstothebridgesystemcouldcauseexcessivemaintenanceissues.Inestimationoflife‑cyclecost,specializedbearinginspections,potential costimpactforbearings,andexpansionjointsreplacementstheisolationbearingsuppliersshouldbeconsulted.



Ifthecolumnsorpierwallsaredesignedforelasticforces,allotherelementsshallbedesignedforthelesseroftheforcesresultingfromtheoverstrengthplastichingingmomentcapacityofcolumnsorpierwallsandtheunreducedelasticseismicforceinall SDCs.Theminimumdetailingaccordingtothebridgeseismicdesigncategoryshallbeprovided.Sheardesignshallbebasedon1.2timeselasticshearforceandnominalmaterialstrengthsshallbeusedforcapacities.LimitationsontheuseofERSandEREareshowninFigures3.3‑1a,3.3‑1b,3.3‑2,and3.3‑3.

• Figure3.3‑1bType6,connectionwithmomentreducingdetailshouldonlybeusedatcolumnbaseifprovednecessaryforfoundationdesign.FixedconnectionatbaseofcolumnremainsthepreferredoptionforWSDOTbridges.

• Thedesigncriteriaforcolumnbasewithmomentreducingdetailshallconsiderall applicableloadsatservice,strength,andextremeeventlimitstates.

• Figure3.3‑2Types6and8arenotpermissiblefornon‑liquefiedconfigurationandpermissiblewithWSDOTBridgeDesignEngineer’sapprovalforliquefiedconfiguration

ForERSsandEREsrequiring approval,theWSDOTBridgeDesignEngineer’sapprovalisrequiredregardlessofcontractingmethod(i.e.,approvalauthorityisnottransferredtootherentities).



BDM Chapter 4 Seismic Design and Retrofit

BridgeDesignManualM23‑50‑02 Page1

Figure 3.3-1a Permissible Earthquake-Resisting Systems (ERSs).

1

Longitudinal Response

Permissible

Plastichingesininspectablelocations.

AbutmentresistancenotrequiredaspartofERS

Knock‑offbackwallspermissible

Transverse Response

2

Longitudinal Response

Isolationbearingsaccommodatefulldisplacement

AbutmentnotrequiredaspartofERS

PermissibleUponApproval

3Permissible


AbutmentnotrequiredinERS,breakawayshearkeyspermissiblewithWSDOTBridgeDesignEngineer’sApproval

4

Transverse or Longitudinal Response

Plastichingesininspectablelocations

Isolationbearingswithorwithoutenergydissipaterstolimitoveralldisplacements


5

Transverse or Longitudinal Response


Abutmentrequiredtoresistthedesignearthquakeelastically

Longitudinalpassivesoilpressureshallbelessthan0.70ofthevalueobtainedusingtheproceduregiveninArticle5.2.3

6Longitudinal Response

Multiplesimply‑supportedspanswithadequatesupportlengths


NotPermissible

Figure 3.3‑1a Permissible Earthquake‑Resisting Systems (ERSs)BDM Figure 4.2.2‑1



Columnswitharchitectural flares– withorwithoutanisolationgap SeeArticle8.14

Seatabutmentswhosebackwallisdesignedtoresisttheexpectedimpactforceinanessentiallyelasticmanner

3

Pierwallswithorwithoutpiles.

SpreadfootingsthatsatisfytheoverturningcriteriaofArticle6.3.4

Capacity-protectedpilecaps,includingcapswithbatteredpiles,whichbehaveelastically

Piles with ‘pinned-head’ conditions

Seismicisolationbearingsorbearingsdesignedtoaccommodateexpectedseismicdisplacementswithnodamage

Plastichingesbelowcapbeamsincludingpilebents

Aboveground/neargroundplastichinges

Tensileyieldingandinelasticcompressionbucklingofductileconcentricallybracedframes

Plastichingesatbaseofwallpiersinweakdirection

Seatabutmentswhosebackwallisdesignedtofuse

PassiveabutmentresistancerequiredaspartofERS Use70%ofpassivesoilstrengthdesignatedinArticle5.2.3

isolationgap optional

1

2

4

5 6

7 8

9

10

11

12

13

Permissible


Permissible

NotPermissible


Permissible



Permissible exceptbatteredpilesarenotallowed

Permissible


Permissible– isolationgapisrequired

14

Permissible

Columnswithmomentreducingorpinnedhingedetails

Permissible

Figure 3.3‑1b Permissible Earthquake‑Resisting Elements (EREs)BDM Figure 4.2.2‑2



Figure 3.3-2 Permissible Earthquake-Resisting Elements that Require Owner’s Approval

1 Passive abutment resistance required as part of ERS Passive StrengthUse 100% of strength designated in Article 5.2.3

2

3Ductile End-diaphragms in superstructure (Article 7.4.6) 4

Sliding of spread footing abutment allowed to limit force transferred

Limit movement to adjacent bent displacement capacity

Foundations permitted to rock

Use rocking criteria according to Appendix A

5

More than the outer line of piles in group systems allowed to plunge or uplift under seismic loadings

6Wall piers on pile foundations that are not strong enough to force plastic hinging into the wall, and are not designed for the Design Earthquake elastic forces

Ensure Limited Ductility Response in Piles according to Article 4.7.1

7Plumb piles that are not capacity-protected (e.g., integral abutment piles or pile-supported seat abutments that are not fused transversely)

Ensure Limited Ductility Response in Piles

8In-ground hinging in shafts or piles.


9

Batter pile systems in which the geotechnical capacities and/or in-ground hinging define the plastic mechanisms.


NotPermissible



NotPermissible

NotPermissible

NotPermissible

NotPermissible

PermissibleUponApprovalforLiquefiedConfiguration

PermissibleUponApprovalforLiquefiedConfiguration

Figure 3.3‑2 Permissible Earthquake‑Resisting Elements That Require Owner’s ApprovalBDM Figure 4.2.2‑3



Figure 3.3-3 Earthquake-Resisting Elements that Are Not Recommended for New Bridges

NotPermissible

Bearing systems that do not provide for the expected displacements and/or forces (e.g., rocker bearings)

Battered-pile systems that are not designed to fuse geotechnically or structurally by elements with adequate ductility capacity

Cap beam plastic hinging (particularly hinging that leads to vertical girder movement) also includes eccentric braced frames with girders supported by cap beams

Plastic hinges in superstructure

12

3 4

NotPermissible

NotPermissible

NotPermissible

Figure 3.3‑3 Earthquake‑Resisting Elements that Are Not Recommended for New BridgesBDM Figure 4.2.2‑4

4.2.3 Seismic Ground Shaking Hazard

Guide Specifications Article 3.4–ForbridgesthatareconsideredcriticaloressentialornormalbridgeswithasiteClassF,theseismicgroundshakinghazardshallbedeterminedbasedontheWSDOTGeotechnicalEngineerrecommendations.

4.2.4 Selection of Seismic Design Category (SDC)

Guide Specifications Article 3.5–PushoveranalysisshallbeusedtodeterminedisplacementcapacityforbothSDCsCandD.

4.2.5 Temporary and Staged Construction

Guide Specifications Article 3.6–Forbridgesthataredesignedforareducedseismicdemand,thecontractplansshalleitherincludeastatementthatclearlyindicatesthat thebridgewasdesignedastemporaryusingareducedseismicdemandorshowtheAccelerationResponseSpectrum(ARS)usedfordesign.

4.2.6 Load and Resistance Factors

Guide Specifications Article 3.7–Reviseasfollows:

Useloadfactorsof1.0forallpermanentloads.Theloadfactorforliveloadshallbe0.0 whenpushoveranalysisisusedtodeterminethedisplacementcapacity.Useliveloadfactorof0.5forallotherextremeeventcases.Unlessotherwisenoted,allϕfactorsshallbetakenas1.0.



4.2.7 Balanced Stiffness Requirements and Balanced Frame Geometry Recommendation

Guide Specifications Articles 4.1.2 and 4.1.3–BalancedstiffnessandbalancedframegeometryarerequiredforbridgesinbothSDCsCandD.DeviationsfrombalancedstiffnessandbalancedframegeometryrequirementsrequireapprovalfromtheWSDOTBridgeDesignEngineer.

4.2.8 Selection of Analysis Procedure to Determine Seismic Demand

Guide Specifications Article 4.2–AnalysisProcedures:

• Procedure1(EquivalentStaticAnalysis)shallnotbeused.

• Procedure2(ElasticDynamicAnalysis)shallbeusedforall“regular”bridgeswithtwo throughsixspans and“notregular”bridgeswithtwoormorespansinSDCsB,C,or D.

• Procedure3(NonlinearTimeHistory)shallonlybeusedwithWSDOTBridgeDesignEngineer’sapproval.

4.2.9 Member Ductility Requirement for SDCs C and D

Guide Specifications Article 4.9–In‑groundhingingfordrilledshaftandpilefoundationsmaybeconsideredfortheliquefiedconfigurationwithWSDOTBridgeDesignEngineerapproval.

4.2.10 Longitudinal Restrainers

Guide Specifications Article 4.13.1 – Longitudinalrestrainersshallbeprovidedattheexpansionjointsbetweensuperstructuresegments.RestrainersshallbedesignedinaccordancewiththeFHWASeismic Retrofitting Manual for Highway Structure (FHWA‑HRT‑06‑032)Article8.4TheIterativeMethod.SeetheearthquakerestrainerdesignexampleintheAppendixofthischapter.RestrainersshallbedetailedinaccordancewiththerequirementsofGuideSpecificationsArticle4.13.3andSection4.4.5.RestrainersmaybeomittedforSDCsCandDwheretheavailableseatwidthexceedsthecalculatedsupportlengthspecifiedinEquationC4.13.1‑1.

OmittingrestrainersforliquefiablesitesshallbeapprovedbytheWSDOTBridgeDesignEngineer.

Longitudinalrestrainersshallnotbeusedattheendpiers(abutments).

4.2.11 Abutments

Guide Specifications Article 5.2–DiaphragmAbutmenttypeshowninFigure5.2.3.2‑1shallnotbeusedforWSDOTbridges.

WithWSDOTBridgeDesignEngineer'sapproval,theabutmentmaybeconsideredanddesignedaspartofearthquakeresistingsystem(ERS)inthelongitudinaldirectionofastraightbridgewithlittleornoskewandwithacontinuousdeck.Fordeterminingseismicdemand,longitudinalpassivesoilpressureshallnotexceed50percentofthevalueobtainedusingtheproceduregiveninArticle5.2.3.3.

Participationofthewingwallinthetransversedirectionshallnotbeconsideredintheseismicdesignofbridges.



4.2.12 Foundation – General

Guide Specifications Article 5.3.1 – The required foundation modeling method (FMM) and the requirements for estimation of foundation springs for spread footings, pile foundations, and drilled shafts shall be based on the WSDOT Geotechnical Engineer’s recommendations.

4.2.13 Foundation – Spread Footing

Guide Specifications Article C5.3.2 – Foundation springs for spread footings shall be determined in accordance with Section 7.2.7, WSDOT Geotechnical Design Manual Section 6.5.1.1 and the WSDOT Geotechnical Engineer’s recommendations.

4.2.14 Procedure 3: Nonlinear Time History Method

Guide Specifications Article 5.4.4 – The time histories of input acceleration used to describe the earthquake loads shall be selected in consultation with the WSDOT Geotechnical Engineer and the WSDOT Bridge Design Engineer.

4.2.15 Ieff for Box Girder Superstructure

Guide Specifications Article 5.6.3 – Gross moment of inertia shall be used for box girder superstructure modeling.

4.2.16 Foundation Rocking

Guide Specifications Article 6.3.9 – Foundation rocking shall not be used for the design of WSDOT bridges.

4.2.17 Drilled Shafts

Guide Specifications Article C6.5 – It is cautioned that the scaling factor for diameter effects should not be used blindly without a sound mechanistic basis. A significant amount of pile load test data have been accumulated within the offshore industry on large diameter driven steel pipe piles including tests on 5 ft (1.5 m) piles. The diameter effects for offshore piles have either been concluded not valid or considered insignificant within the offshore industry. Juirnarongrit and Ashford (2005) performed vibration tests and lateral load tests on drilled shafts ranging from 16 in (0.4 m) to 4 ft (1.2 m) installed in dense weakly cemented sand. Data from the tests for each shaft diameter were used to back‑calculate p‑y curves. Their analyses indicate that the shaft diameter has insignificant effect on the p-y curves at the displacement level below the ultimate soil resistance. Beyond this range, the ultimate soil resistance increased as the shaft diameter increased. It is found that the pile diameter effect depend on the pile head moment-to-shear ratio and the distribution of soil modulus with depth (Pender, 2004). For WSDOT bridges, the scale factor for p-y curves for large diameter shafts shall not be used unless approved by the WSDOT Geotechnical Engineer and WSDOT Bridge Design Engineer.

4.2.18 Longitudinal Direction Requirements

Guide Specifications Article 6.7.1 – Case 2: Earthquake Resisting System (ERS) with abutment contribution may be used provided that the mobilized longitudinal passive pressure is not greater than 50 percent of the value obtained using procedure given in Article 5.2.3.3.



4.2.19 Liquefaction Design Requirements

Guide Specifications Article 6.8–SoilliquefactionassessmentshallbebasedontheWSDOTGeotechnicalEngineer’srecommendationandWSDOTGeotechnical Design Manual Section6.4.2.8.

4.2.20 Reinforcing Steel

Guide Specifications Article 8.4.1–ASTMA615reinforcementshallnotbeusedinWSDOTBridges.OnlyASTMA706Grade60reinforcingsteelshallbeusedinmemberswhereplastichingingisexpectedforSDCsB,C,andD.ASTMA706Grade80reinforcingsteelsmaybeusedforcapacity‑protectedmembersspecifiedinArticle8.9.ASTMA706Grade80reinforcingsteelshallnotbeusedforoversizedshaftswherein‑groundplastichingingisconsideredasapartofERS.

DeformedweldedwirefabricmaybeusedwiththeWSDOTBridgeDesignEngineer’sapproval.

Wireropeorstrandsforspiralsandhighstrengthbarswithyieldstrengthinexcessof75ksi shallnotbeused.

Guide Specifications Article C8.4.1–AddthefollowingparagraphtoArticleC8.4.1.

TherequirementforplastichingingandcapacityprotectedmembersdonotapplytothestructuresinSDCA,thereforeuseofASTMA706Grade80reinforcingsteelispermittedinSDCA.

ForSDCsB,C,andDmoment‑curvatureanalysisbasedonstraincompatibilityandnonlinearstress‑strainrelationsareusedtodeterminetheplasticmomentcapacityofallductileconcretemember,furtherresearchisrequiredtoestablishtheshapeandmodelofthestress‑straincurve,expectedreinforcingstrengths,strainlimits,andthestress‑strainrelationshipsforconcreteconfinedbylateralreinforcementmadewithASTMA706Grade80reinforcingsteel.

4.2.21 Concrete Modeling

Wherein‑groundplastichingingapprovedbyWSDOTBridgeDesignEngineerispartoftheERS,theconfinedconcretecoreshallbelimitedtoamaximumcompressivestrainof0.008.Theclearspacingbetweenlongitudinalreinforcementsandbetweenspiralsandhoopsshallnot belessthan6inormorethan9in.

4.2.22 Expected Nominal Moment Capacity

Guide Specifications Article 8.5–Add thefollowingparagraphsafterthirdparagraph.

TheexpectednominalcapacityofcapacityprotectedmemberusingASTMA706Grade80reinforcementshallbedeterminedbystrengthdesignbasedontheexpectedconcretestrengthandyieldstrengthof80ksiwhentheconcretereaches0.003orthereinforcingsteelstrainreaches0.090for#10barsandsmaller,0.060for#11barsandlarger.



4.2.23 Interlocking Bar Size

Guide Specifications Article 8.6.7–Thelongitudinalreinforcingbarinsidetheinterlockingportionofcolumn(interlockingbars)shallbethesamesizeofbarsusedoutsidetheinterlockingportion.

4.2.24 Splicing of Longitudinal Reinforcement in Columns Subject to Ductility Demands for SDCs C and D

Guide Specifications Article 8.8.3–Thesplicingoflongitudinalcolumnreinforcementoutsidetheplastichingingregionshallbeaccomplishedusingmechanicalcouplersthatarecapableofdevelopingaminimumtensilestrengthof85ksi.Splicesshallbestaggeredatleast2ft.Lapsplicesshallnotbeused.Thedesignengineershallclearlyidentifythelocationswheresplicesinlongitudinalcolumnreinforcementarepermittedontheplans.Ingeneralwherethelengthoftherebarcageislessthan60ft(72ftforNo.14andNo.18bars),nospliceinlongitudinalreinforcementsshallbeallowed.

4.2.25 Development Length for Column Bars Extended into Oversized Pile Shafts f or SDCs C and D

Guide Specifications Article 8.8.10–ExtendingcolumnbarsintooversizedshaftshallbeperSection7.4.4.C,basedonTRACReportWA‑RD417.1“NonContactLapSpliceinBridgeColumn‑ShaftConnections.”

4.2.26 Lateral Confinement for Oversized Pile Shaft for SDCs C and D

Guide Specifications Article 8.8.12–Therequirementofthisarticleforshaftlateralreinforcementinthecolumn‑shaftsplicezonemaybereplacedwithSection7.8.2Kofthismanual.

4.2.27 Lateral Confinement for Non‑Oversized Strengthened Pile Shaft for SDCs C and D

Guide Specifications Article 8.8.13–Non‑oversizedcolumn‑shaftisnotpermissibleunlessapprovedbytheWSDOTBridgeDesignEngineer.

4.2.28 Requirements for Capacity Protected Members

Guide Specifications Article 8.9–Addthefollowingparagraphs:

ForSDCsCandDwhereliquefactionisidentified,withtheWSDOTBridgeDesignEngineer’sapproval,pileanddrilledshaftin‑groundhingingmaybeconsideredasanERE.Wherein‑groundhingingispartofERS,theconfinedconcretecoreshouldbelimitedtoamaximumcompressivestrainof0.008andthememberductilitydemandshallbelimitedto4.

BridgesshallbeanalyzedanddesignedforthenonliquefiedconditionandtheliquefiedconditioninaccordancewithArticle6.8.ThecapacityprotectedmembersshallbedesignedinaccordancewiththerequirementsofArticle4.11.Toensuretheformationofplastichingesincolumns,oversizedpileshaftsshallbedesignedforanexpectednominalmomentcapacity,Mne,atanylocationalongtheshaft,thatis,equalto1.25timesmomentdemandgeneratedbytheoverstrengthcolumnplastichingemoment



andassociatedshearforceatthebaseofthecolumn.Thesafetyfactorof1.25maybereducedto1.0dependingonthesoilpropertiesandupontheWSDOTBridgeDesignEngineer’sapproval.

Thedesignmomentsbelowgroundforextendedpileshaftmaybedeterminedusingthenonlinearstaticprocedure(pushoveranalysis)bypushingthemlaterallytothedisplacementdemandobtainedfromanelasticresponsespectrumanalysis.Thepointofmaximummomentshallbeidentifiedbasedonthemomentdiagram.Theexpectedplastichingezoneshallextend3Daboveandbelowthepointofmaximummoment.Theplastichingezoneshallbedesignatedasthe“no‑splice”zoneandthetransversesteelforshearandconfinementshallbeprovidedaccordingly.

4.2.29 Superstructure Capacity Design for Transverse Direction (Integral Bent Cap) for SDCs C and D

Guide Specifications Article 8.11–Revisethelastparagraphasfollows:

ForSDCsCandD,thelongitudinalflexuralbentcapbeamreinforcementshallbecontinuous.Splicingofcapbeamlongitudinalflexuralreinforcementshallbeaccomplishedusingmechanicalcouplersthatarecapableofdevelopingaminimumtensilestrengthof85ksi.Splicesshallbestaggeredatleast2ft.Lapsplicesshallnotbeused.

4.2.30 Superstructure Design for Non Integral Bent Caps for SDCs B, C, and D

Guide Specifications Article 8.12–NonintegralbentcapsshallnotbeusedforcontinuousconcretebridgesinSDCB,C,andDexceptattheexpansionjointsbetweensuperstructuresegments.

4.2.31 Joint Proportioning

Guide Specifications Article 8.13.2 –ReviseArticle8.13.2asfollows:

Moment‑resistingjointsshallbeproportionedsothattheprincipalstressessatisfytherequirementsofEq.1andEq.2

• Forprincipalcompression,pc: 4.2.40

8.13.2‐1 �� 0.��

8.13.2‐2 �� 0.��

8.13.2‐3 ��

� ��

8.13.2‐4 ��

� ��

8.13.2‐5 ��

8.13.2‐6 �v � ��

8.13.2‐7 ��

8.13.2‐8 ��

8.13.2‐9 ��

4.2.21 0.11��

(8 .13 .2‑1)

• Forprincipaltension,pt:

4.2.40

8.13.2‐1 �� 0.��

8.13.2‐2 �� 0.��

8.13.2‐3 ��

� ��

8.13.2‐4 ��

� ��

8.13.2‐5 ��

8.13.2‐6 �v � ��

8.13.2‐7 ��

8.13.2‐8 ��

8.13.2‐9 ��

4.2.21 0.11��

(8 .13 .2‑2)

Inwhich:

4.2.10 (C4.9-1) ∆𝑦𝑦𝑦𝑦=𝜙𝜙𝑦𝑦𝑦𝑦𝐿𝐿2

3

(C4.9-2) ∆𝑝𝑝𝑝𝑝= �𝜙𝜙𝑐𝑐𝑐𝑐𝑐𝑐 − 𝜙𝜙𝑦𝑦𝑦𝑦�𝐿𝐿𝑝𝑝�𝐿𝐿 − 0.5𝐿𝐿𝑝𝑝�

(C4.9-3) 𝜇𝜇𝐷𝐷 = 1 + 𝛥𝛥𝑝𝑝𝑝𝑝𝛥𝛥𝑦𝑦𝑦𝑦

(C4.9-4) 𝜇𝜇𝐷𝐷 = 1 + 3 �𝜙𝜙𝑐𝑐𝑐𝑐𝑐𝑐𝜙𝜙𝑦𝑦𝑦𝑦

− 1� 𝐿𝐿𝑝𝑝𝐿𝐿�1 − 0.5 𝐿𝐿𝑝𝑝

𝐿𝐿�

4.2.13 𝑁𝑁 = �4 + 𝟐𝟐.𝟎𝟎∆𝑒𝑒𝑒𝑒�(1 + 0.00025𝑆𝑆2) ≥ 24 𝑖𝑖𝑖𝑖.

4.2.18 𝑃𝑃𝑓𝑓′𝑐𝑐𝑐𝑐𝐴𝐴𝑔𝑔

4.2.21 0.11�𝑓𝑓′𝑐𝑐

𝐴𝐴𝑠𝑠𝑗𝑗𝑗𝑗

𝐴𝐴𝑠𝑠𝑠𝑠

𝐴𝐴𝑠𝑠𝑗𝑗𝑓𝑓

6.4.8-1 𝐴𝐴𝑠𝑠𝑗𝑗𝑗𝑗 ≥ 0.80𝐴𝐴𝑠𝑠𝑠𝑠

6.4.9-1 𝐴𝐴𝑠𝑠𝑗𝑗𝑓𝑓 ≥ 0.09𝐴𝐴𝑠𝑠𝑠𝑠

4.2.26 8.5-1 𝑀𝑀𝑝𝑝𝑐𝑐 = 𝜆𝜆𝑚𝑚𝑐𝑐𝑀𝑀𝑝𝑝 ≥ 𝑀𝑀𝑚𝑚𝑚𝑚𝑚𝑚

𝜀𝜀𝑅𝑅𝑠𝑠𝑠𝑠

4.2.40

8.13.2-1 𝑝𝑝𝑐𝑐 ≤ 0.25𝑓𝑓′𝑐𝑐

8.13.2-2 𝑝𝑝𝑠𝑠 ≤ 0.38�𝑓𝑓′𝑐𝑐

8.13.2-3 𝑝𝑝𝑠𝑠 = �𝑓𝑓ℎ+𝑓𝑓𝑣𝑣2� − ��𝑓𝑓ℎ−𝑓𝑓𝑣𝑣

2�2

+ 𝑣𝑣𝑗𝑗ℎ2

8.13.2-4 𝑝𝑝𝑐𝑐 = �𝑓𝑓ℎ+𝑓𝑓𝑣𝑣2� + ��𝑓𝑓ℎ−𝑓𝑓𝑣𝑣

2�2


8.13.2-5 𝑓𝑓ℎ = 𝑃𝑃𝑏𝑏𝐵𝐵𝑐𝑐𝑐𝑐𝑝𝑝𝐷𝐷𝑠𝑠

8.13.2-6 𝑓𝑓v = 𝑃𝑃𝑐𝑐(𝐷𝐷𝑐𝑐+𝐷𝐷𝑏𝑏)𝐵𝐵𝑐𝑐𝑐𝑐𝑝𝑝

(8 .13 .2‑3)


3





𝐿𝐿�

4.2.13 𝑁𝑁 = �4 + 𝟐𝟐.𝟎𝟎∆𝑒𝑒𝑒𝑒�(1 + 0.00025𝑆𝑆2) ≥ 24 𝑖𝑖𝑖𝑖.


4.2.21 0.11�𝑓𝑓′𝑐𝑐








4.2.40

8.13.2-1 𝑝𝑝𝑐𝑐 ≤ 0.25𝑓𝑓′𝑐𝑐

8.13.2-2 𝑝𝑝𝑠𝑠 ≤ 0.38�𝑓𝑓′𝑐𝑐


2�2



2�2




(8 .13 .2‑4)

Where: ƒh = Average axial horizontal stress (ksi) ƒv = Average axial vertical stress (ksi) vjh = Average joint shear stress (ksi)



Thehorizontalaxialstressisbasedonthemeanaxialforceatthecenterofjoint.


3





𝐿𝐿�

4.2.13 𝑁𝑁 = �4 + 𝟐𝟐.𝟎𝟎∆𝑒𝑒𝑒𝑒�(1 + 0.00025𝑆𝑆2) ≥ 24 𝑖𝑖𝑖𝑖.


4.2.21 0.11�𝑓𝑓′𝑐𝑐








4.2.40

8.13.2-1 𝑝𝑝𝑐𝑐 ≤ 0.25𝑓𝑓′𝑐𝑐

8.13.2-2 𝑝𝑝𝑠𝑠 ≤ 0.38�𝑓𝑓′𝑐𝑐


2�2



2�2




(8 .13 .2‑5)

Where: Pb = Beam axial force at the center of the joint including the effects of prestressing and the shear associated with plastic hinging (kips) Bcap= Bent cap width (in) Ds = Depth of superstructure at the bent cap for integral joints under longitudinal response and depth of cap beam for nonintegral bent caps and integral joint under transverse response (in)

Formostprojects, ƒhcantypicallybeignoredsincethereistypicallynoprestressinthecap.

Intheverticaldirection,theaverageaxialstressinthejointisprovidedbytheaxialforceinthecolumn.Assuminga45°spreadawayfromtheboundaryofthecolumntoaplaneatmid‑depthofthebentcap,theaverageaxialstressiscalculatedbythefollowingequation:

4.2.40

8.13.2‐1 �� 0.��

8.13.2‐2 �� 0.��

8.13.2‐3 ��

� ��

8.13.2‐4 ��

� ��

8.13.2‐5 ��

8.13.2‐6 �v � ��

8.13.2‐7 ��

8.13.2‐8 ��

8.13.2‐9 ��

4.2.21 0.11��

(8 .13 .2‑6)

Where: Pc = Column axial force including the effects of overturning (kips) Bcap = Bent cap width (in) Dc = Diameter or cross‑sectional dimension of column parallel to bent cap (in) Db = Depth of bent cap (in)

Eq.6shall bemodified ifthecapbeamdoesnotextendbeyondthecolumnexteriorfacegreaterthanthebentcapdepth.

Theaveragejointshearstress,vjh,canbeapproximatedwiththefollowingequation:

4.2.40

8.13.2‐1 �� 0.��

8.13.2‐2 �� 0.��

8.13.2‐3 ��

� ��

8.13.2‐4 ��

� ��

8.13.2‐5 ��

8.13.2‐6 �v � ��

8.13.2‐7 ��

8.13.2‐8 ��

8.13.2‐9 ��

4.2.21 0.11��

(8 .13 .2‑7)

Where: M = The column overstrength moment, Mpo, in addition to the moment induced due to eccentricity between the column plastic hinge location and the c .g . of bottom longitudinal reinforcement of the cap beam or superstructure (kip‑in) Dc = Diameter or cross‑sectional dimension of column in the direction of loading (in) hb = The distance from c .g . of tensile force to c .g . of compressive force on the section (in) This level arm may be approximated by Ds . Beff = Effective width of joint (in)

Theeffectivewidthofjoint,Beff,dependsontheshapeofthecolumnframingintothejointandisdeterminedusingthefollowingequations.

• Forcircularcolumns: 8.13.2-7 𝑣𝑣𝑗𝑗ℎ = 𝑀𝑀

ℎ𝑏𝑏𝐷𝐷𝑐𝑐𝐵𝐵𝑒𝑒𝑒𝑒𝑒𝑒

8.13.2-8 𝐵𝐵𝑒𝑒𝑒𝑒𝑒𝑒 = √2 𝐷𝐷𝑐𝑐

8.13.2-9 𝐵𝐵𝑒𝑒𝑒𝑒𝑒𝑒 = 𝐵𝐵𝑐𝑐 + 𝐷𝐷𝑐𝑐

4.2.45 𝜃𝜃𝑝𝑝 = 𝐿𝐿𝑝𝑝�𝜙𝜙𝑢𝑢 − 𝜙𝜙𝑦𝑦�

(8 .13 .2‑8)

• Forrectangularcolumns:

4.2.40

8.13.2‐1 �� 0.��

8.13.2‐2 �� 0.��

8.13.2‐3 ��

� ��

8.13.2‐4 ��

� ��

8.13.2‐5 ��

8.13.2‐6 �v � ��

8.13.2‐7 ��

8.13.2‐8 ��

8.13.2‐9 ��

4.2.21 0.11��

(8 .13 .2‑9)



Fortransverseresponse,theeffectivewidthwillbethesmallerofthevaluegivenby theaboveequationsorthecapbeamwidth.Figure8.13.2‑1clarifiesthequantitiestobeusedinthiscalculation.


BridgeDesignManualM23‑50‑02 Page2

Fortransverseresponse,theeffectivewidthwillbethesmallerofthevaluegivenbytheaboveequationsorthecapbeamwidth.Figure8.13.2‑1clarifiesthequantitiestobeusedinthiscalculation.

where:

Bc = diameterorwidthofcolumnorwallmeasurednormaltothedirectionofloading(in.)

Figure 8.13.2-1 Effective Joint Width for Shear Stress Calculation.

Figure 8.13.2‑1 Effective Joint Width for Shear Stress CalculationBDM Figure 4.2.30‑1

4.2.32 Cast-in-Place and Precast Concrete Piles

Guide Specifications Article 8.16.2–Minimumlongitudinalreinforcementof0.75percentofAgshallbeprovidedforCIPpilesinSDCsB,C,andD.LongitudinalreinforcementshallbeprovidedforthefulllengthofpileunlessapprovedbytheWSDOTBridgeDesignEngineer.



4.3 Seismic Design Requirements for Bridge Widening Projects4.3.1 Seismic Analysis and Retrofit Policy

Wideningofexistingbridgesisoftenchallenging,specificallywhenitcomestodetermininghowtoaddresselementsoftheexistingstructurethatdonotmeetcurrentdesignstandards.TheSeismicAnalysisandRetrofitPolicyforBridgeWideningProjects(Figure4.3‑1)hasbeenestablishedtogivebridgedesignengineersguidanceonhowandwhentoaddressstructuraldeficienciesinexistingbridgesthatarebeingwidened.Thispolicybalancestheengineersresponsibilityto“safeguardlife,health,andproperty”(WAC196‑27A‑020)withtheirresponsibilityto“achievethegoalsandobjectivesagreeduponwiththeirclientoremployer”(WAC196‑27A‑020(2)(a)).Currentversionsofbridgedesignspecifications/codesdonotprovideguidanceonhowtotreatexistingstructuresthatarebeingwidened.ThispolicyisbasedonandvalidatedbytherequirementsoftheInternationalBuildingCode(2009IBCSection3403.4).TheIBCisthecodeusedthroughoutthenationfordesignofmost structuresotherthanbridges.Thus,therequirementsoftheIBCcanbetakentoprovideanacceptablelevelofsafetythatmeetstheexpectationsofthepublic.

This“DoNoHarm”policyrequiresthebridgeengineertocompareexistingbridgeelementseismiccapacity/demandratiosforthebeforewideningconditiontothoseoftheafterwideningcondition.Ifthecapacity/demandratioisnotdecreased,thewideningcanbedesignedandconstructedwithoutretrofittingexistingseismicallydeficientbridgeelements.Inthiscaseretrofitofseismicallydeficientelementsisrecommendedbutnotrequired.Thedecisiontoretrofittheseelementsislefttotheregionandisbasedonfundingavailability.Ifthewidenedcapacity/demandratiosaredecreased,theseismicallydeficientexistingelementsmustberetrofitted aspartofthewideningproject.

Thispolicyallowsbridgewideningprojectstobecompletedwithoutaddressingexistingseismicrisks,provided“NoHarm”isdonetotheexistingstructure.Theexistingseismicrisksarelefttobeaddressedbyabridgeseismicretrofitproject.ThisapproachmaintainstheprioritiesthathavebeensetbytheWashingtonStateLegislature.MostwideningprojectsarefundedbytheI1‑MobilityProgram.TheobjectiveoftheI1‑MobilityProgramistoimprovemobility…nottoaddressseismicrisks.BridgeseismicrisksareaddressedthroughbridgeseismicretrofitprojectsthatarefundedaspartoftheP2‑StructuresPreservationProgram.TheLegislaturehasestablishedthepriorityoftheseandother programsandsetfundinglevelsaccordingly.ThispolicyupholdstheprioritiesestablishedbytheLegislature,byaccomplishingwidening(mobility)projectswithoutrequiringthatretrofit(preservation/riskreduction)workbeaddedtothescope,providedtheexistingstructureisnotmade worse.

Wideningelements(newstructure)shallbedesignedtomeetcurrentWSDOTstandardsfornewbridges.

Aseismicanalysisisnotrequiredforsingle‑spanbridges.However,existingelementsofsinglespanbridges shallmeettherequirementsofAASHTO Guide Specifications for LRFD Seismic Bridge Design Section4.5.



AseismicanalysisisnotrequiredforbridgesinSDCA.However,existingelementsofbridgesinSDCAshallmeettherequirementsofAASHTO Guide Specifications for LRFD Seismic Bridge DesignSection4.6.

Whentheadditionofthewideninghasinsignificanteffectsontheexistingstructureelements,theseismicanalysismaybewaivedwiththeWSDOTBridgeDesignEngineer’sapproval.Inmanycases,addinglessthan10percentmasswithoutnewsubstructurecouldbeconsideredinsignificant.



C/DPost ≥ 1.0

C/DPost ≥ C/DPre (See Note 3)

No

NoCan widening design be revised to result in

C/DPost ≥ C/DPre

Revise widening design (reduce mass, increase

stiffness, etc.)

Yes

Perform seismic analysis of existing and widened structure. Generate C/DPre and C/Dpost for all applicable existing bridge elements (including

foundation elements). (See Notes 1 and 2)

Seismic performance maintained Retrofit of element recommended

but not required (optional)

Element is adequate as is no seismic retrofit required

Yes

Yes No

Prepare preliminary cost estimates including:• Widening plus recommended seismic retrofits estimate

(widening + required seismic retrofits + optional seismic retrofits)• Base widening estimate

(widening + required seismic retrofits)• Bridge replacement estimate

(only required for widening projects with required seismic retrofits)

Region select from the following alternatives:• Widen bridge and perform required

and optional seismic retrofits• Widen bridge and perform required

seismic retrofits• Replace bridge• Cancel project

Report C/DPre and DPost ratios, along with final project scope to bridge management group. This information will be used

to adjust the status of the bridge in the seismic retrofit program.

Seismic performance made worse retrofit of element

is required

Legend: C/DPre = Existing bridge element seismic capacity demand ratio before widening C/DPost = Existing bridge element seismic capacity demand ratio after widening

Notes: 1 . Widening elements (new structure) shall be designed to meet current WSDOT standards for New Bridges . 2 . Seismic analysis shall account for substandard details of the existing bridge . 3 . C/D ratios are evaluated for each existing bridge element .

WSDOT Seismic Analysis and Retrofit Policy for Bridge Widening ProjectsFigure 4.3.1‑1



4.3.2 Design and Detailing Considerations

Support Length–Thesupportlengthatexistingabutments,piers,in‑spanhinges,andpavementseatsshallbechecked.Ifthereisaneedforlongitudinalrestrainers,transverserestrainers,oradditionalsupportlengthontheexistingstructure,theyshallbeincludedinthewideningdesign.

Connections Between Existing and New Elements–Connectionsbetweenthenewelementsandexistingelementsshouldbedesignedformaximumover‑strengthforces.Whereyieldingisexpectedinthecrossbeamconnectionattheextremeeventlimitstate,thenewstructureshallbedesignedtocarryliveloadsindependentlyattheStrengthIlimitstate.Incaseswherelargedifferentialsettlementand/oraliquefaction‑inducedlossofbearingstrengthareexpected,theconnectionsmaybedesignedtodeflectorhingeinordertoisolatethetwopartsofthestructure.Elementssubjecttoinelasticbehaviorshallbedesignedanddetailedtosustaintheexpecteddeformations.

Longitudinaljointsbetweentheexistingandnewstructurearenotpermitted.

Differential Settlement–Theallowabledifferentialsettlementofbridgesdependson thetypeofconstruction,thetypeoffoundation,andthenatureofsoil(sandorclay).Thegeotechnicaldesignershouldevaluatethepotentialfordifferentialsettlementbetweentheexistingstructureandwideningstructure.Additionalgeotechnicalmeasuresmayberequiredtolimit differentialsettlementstotolerablelevelsforbothstaticandseismicconditions.Thebridgedesignershallevaluate,design,anddetailallelementsofnewandexistingportionsofthe wideningstructureforthedifferentialsettlementwarrantedbytheGeotechnicalEngineer.Experiencehasshownthatbridgescanandoftendoaccommodatemoremovementand/orrotationthantraditionallyallowedoranticipatedindesign.Creep,relaxation,andredistributionofforceeffectsaccommodatethesemovements.Somestudieshavebeenmadetosynthesizeapparentresponse.Theangulardistortionappearstobetheusefulcriteriaforestablishingtheallowablelimits.Thesestudiesindicatethatangulardistortionsbetweenadjacentfoundationsgreaterthan0.008(RAD)insimplespansand0.004(RAD)incontinuousspansshouldnotbepermittedinsettlementcriteria(Moultonet al.1985; DiMillio,1982;Barker etal.1991).Otherangulardistortionlimitsmaybeappropriateafterconsiderationof:

• Costofmitigationthroughlargerfoundations,realignment,orsurcharge• Rideability• Aesthetics• Safety

Rotationmovementsshouldbeevaluatedatthetopofthesubstructureunit(inplanlocation)andatthedeckelevation.

Thehorizontaldisplacementofpileandshaftfoundationsshallbeestimatedusingproceduresthatconsidersoil‑structureinteraction(seeGeotechnical Design Manual M46‑03Section8.12.2.3).Horizontalmovementcriteriashouldbeestablishedatthetopofthefoundationbasedonthetoleranceofthestructuretolateralmovementwithconsiderationofthecolumnlengthandstiffness.Toleranceofthesuperstructuretolateralmovementwilldependonbridgeseatwidths,bearingtype(s),structuretype,andloaddistributioneffects.



Foundation Types–Thefoundationtypeofthenewstructureshouldmatchthatoftheexistingstructure.However,adifferenttypeoffoundationmaybeusedforthenewstructureduetogeotechnicalrecommendationsorthelimitedspaceavailablebetweenexistingandnewstructures.Forexample,ashaftfoundationmaybeusedinlieu ofspreadfooting.

Existing Strutted Columns–Thehorizontalstrutbetweenexistingcolumnsmayberemoved.Theexistingcolumnsshallthenbeanalyzedwiththenewunbracedlength andretrofittedifnecessary.

Non Structural Element Stiffness–Medianbarrierandotherpotentiallystiffeningelementsshallbeisolatedfromthecolumnstoavoidanyadditionalstiffnesstothesystem.

DeformationcapacitiesofexistingbridgemembersthatdonotmeetcurrentdetailingstandardsshallbedeterminedusingtheprovisionsofSection7.8oftheRetrofitting Manual for Highway Structures: Part 1 – Bridges,FHWA‑HRT‑06‑032.DeformationcapacitiesofexistingbridgemembersthatmeetcurrentdetailingstandardsshallbedeterminedusingthelatesteditionoftheAASHTO Guide Specifications for LRFD Seismic Bridge Design.

JointshearcapacitiesofexistingstructuresshallbecheckedusingCaltransBridge Design Aid,14‑4JointShearModelingGuidelinesforExistingStructures.

Inlieuofspecificdata,thereinforcementpropertiesprovidedinTable4.3.2‑1shouldbeused.

Property Notation Bar Size ASTM A706

ASTM A615 Grade 60

ASTM A615 Grade 40*

Specified minimum yield stress (ksi) ƒy No . 3 ‑ No . 18 60 60 40

Expected yield stress (ksi) ƒye No . 3 ‑ No . 18 68 68 48

Expected tensile strength (ksi) ƒue No . 3 ‑ No . 18 95 95 81

Expected yield strain εye No . 3 ‑ No . 18 0 .0023 0 .0023 0 .00166

Onset of strain hardening εsh

No . 3 ‑ No . 8 0 .0150 0 .0150

0 .0193

No . 9 0 .0125 0 .0125

No . 10 & No . 11 0 .0115 0 .0115

No . 14 0 .0075 0 .0075

No . 18 0 .0050 0 .0050

Reduced ultimate tensile strain


Page 4.3-4 WSDOT Bridge Design Manual M 23-50.06 July 2011

• Deformation capacities of existing bridge members that do not meet current detailing standards shall be determined using the provisions of Section 7.8 of the Retrofitting Manual for Highway Structures: Part 1 – Bridges, FHWA-HRT-06-032. Deformation capacities of existing bridge members that meet current detailing standards shall be determined using the latest edition of the AASHTO Guide Specifications for LRFD Seismic Bridge Design.

• Joint shear capacities of existing structures shall be checked using Caltrans Bridge Design Aid, 14-4 Joint Shear Modeling Guidelines for Existing Structures.

• In lieu of specific data, the reinforcement properties provided in Table 4.3.2-1 should be used.

Property Notation Bar Size ASTM A706

ASTM A615 Grade 60

ASTM A615 Grade 40

Specified minimum yield stress (ksi) ƒy #3 - #18 60 60 40

Expected yield stress (ksi) ƒye #3 - #18 68 68 48

Expected tensile strength (ksi) ƒue #3 - #18 95 95 81

Expected yield strain εye #3 - #18 0 .0023 0 .0023 0 .00166

Onset of strain hardening εsh

#3 - #8 0 .0150 0 .0150

0 .0193#9 0 .0125 0 .0125

#10 & #11 0 .0115 0 .0115#14 0 .0075 0 .0075#18 0 .0050 0 .0050

Reduced ultimate tensile strain


Bridge Design Manual M23-50-02 Page 31

Property Notation Bar Size ASTMA706

ASTM A615 Grade 60

ASTM A615 Grade 40

Specifiedminimum yield stress (ksi)

yf #3 - #18 60 60 40

Expected yield stress (ksi) yef #3 - #18 68 68 48

Expectedtensile strength (ksi)

uef #3 - #18 95 95 81

Expected yield strain ye #3 - #18 0.0023 0.0023 0.00166

Onset of strain hardening sh

#3 - #8 0.0150 0.0150

0.0193

#9 0.0125 0.0125

#10 & #11 0.0115 0.0115

#14 0.0075 0.0075

#18 0.0050 0.0050 Reducedultimate tensile strain

Rsu

#4 - #10 0.090 0.060 0.090

#11 - #18 0.060 0.040 0.060

Ultimate tensile strain su

#4 - #10 0.120 0.090 0.120

#11 - #18 0.090 0.060 0.090

Table 4.3.2-1 Stress Properties of Reinforcing Steel Bars.

#4 - #10 0 .090 0 .060 0 .090#11 - #18 0 .060 0 .040 0 .060

Ultimate tensile strain εsu

#4 - #10 0 .120 0 .090 0 .120#11 - #18 0 .090 0 .060 0 .090

Stress Properties of Reinforcing Steel BarsTable 4.3.2-1

No . 4 ‑ No . 10 0 .090 0 .060 0 .090

No . 11 ‑ No . 18 0 .060 0 .040 0 .060

Ultimate tensile strain εsu

No . 4 ‑ No . 10 0 .120 0 .090 0 .120

No . 11 ‑ No . 18 0 .090 0 .060 0 .090

* ASTM A615 Grade 40 is for existing bridges in widening projects .

Stress Properties of Reinforcing Steel BarsTable 4.3.2-1



Isolation Bearings–Maybeusedforbridgewideningprojectstoreducethedemandsthroughmodificationof thedynamicpropertiesofthebridgeasaviablealternativetostrengtheningweakelementsornonductilebridgesubstructuremembersofexistingbridge.IsolationbearingsshallbedesignedpertherequirementoftheAASHTOGuide Specifications for Seismic Isolation.

Thedecisionforusingisolationbearingsshouldbemadeattheearlystageofprojectdevelopmentbasedonthecomplexityofbridgegeotechnicalandstructuraldesign.Acost‑benefitanalysiscomparingdesignwithstrengtheningweakelementsvs.designwithisolationbearingsshall beperformedandsubmittedforapproval.Thedesignerneedstoperformtwoseparatedesigns,onewithandonewithoutseismicisolationbearings.Thecost‑benefitanalysisshallatleastinclude:

• Higherinitialdesigntime andcomplexityofanalysis.


• Timerequiredforpreliminaryinvestigationandcorrespondenceswiththeisolationbearingsuppliers.

• Life‑cyclecostofadditionalandspecializedandbearinginspections.

• Potentialcostimpactforbearingandexpansionjointsreplacements.



Onceapprovalhasbeengivenfortheuseofseismicisolationbearings,thedesignershallsendasetofpreliminarydesignandspecificationrequirementstoatleastthreeseismic isolationbearingsuppliersforevaluationtoensurethattheycanmeetthedesignandspecificationrequirements.Commentsfromisolationbearingsuppliersshouldbeincorporatedbeforedesignofstructurebegins.SolesourceisolationbearingsuppliermaybeconsidereduponBridgeDesignOfficeandProjectEngineer'sofficeapproval.




4.4 Seismic Retrofitting of Existing BridgesSeismicretrofittingofexistingbridgeswillbeperformedinaccordancewiththeFHWApublication FHWA‑HRT‑06‑032,Seismic Retrofitting Manual for Highway Structures: Part 1 – Bridges.

4.4.1 Seismic Analysis Requirements

Thefirststepin retrofittingabridgeistoanalyzetheexistingstructuretoidentifyseismically deficientelements.Theinitialanalysisconsistsofgeneratingcapacity/demandratiosforallrelevantbridgecomponents.Seismicdisplacementandforcedemandsshallbedeterminedusingthemulti‑modespectralanalysisofSection5.4.2.2(ataminimum).Prescriptiverequirements,suchassupportlength,shallbeconsideredademandandshallbeincludedintheanalysis.Seismiccapacitiesshallbedeterminedinaccordancewiththe requirementsoftheSeismic Retrofitting Manual.DisplacementcapacitiesshallbedeterminedbytheMethodD2–StructureCapacity/Demand(Pushover)MethodofSection5.6.FormostWSDOTbridges,theseismicanalysisneedonlybeperformedfortheupperlevel(1,000yearreturnperiod)groundmotionswithalifesafetyseismicperformancelevel.

4.4.2 Seismic Retrofit Design

Onceseismicallydeficientbridgeelementshavebeenidentified,appropriateretrofitmeasuresshallbeselectedanddesigned.Table1‑11,Chapters8,9,10,11,andAppendicesDthruFoftheSeismic Retrofitting Manualshallbeusedinselectinganddesigningtheseismicretrofitmeasures.TheWSDOTBridgeandStructureOfficeSeismicSpecialistwillbeconsultedintheselectionanddesignoftheretrofitmeasures.

4.4.3 Computer Analysis Verification

Thecomputerresultswillbeverifiedtoensureaccuracyandcorrectness.Thedesignershouldusethefollowingproceduresformodelverification:

• Usinggraphicstochecktheorientationofallnodes,members,supports,joint,andmemberreleases.Makesurethatallthestructuralcomponentsandconnectionscorrectlymodeltheactualstructure.

• Checkdeadloadreactionswithhandcalculations.Thedifferenceshouldbelessthan5percent.

• Calculatefundamentalandsubsequentmodesbyhandandcompareresultswithcomputerresults.

• Checkthemodeshapesandverifythatstructuremovementsarereasonable.

• Increasethenumberofmodestoobtain90percentormoremassparticipationineachdirection.GTSTRUDL/SAP2000directlycalculatesthepercentageofmassparticipation.

• Checkthedistributionoflateralforces.Aretheyconsistentwithcolumnstiffness?Dosmallchangesinstiffnessofcertaincolumnsgivepredictableresults?



4.4.4 Earthquake Restrainers

LongitudinalrestrainersshallbehighstrengthbarsinaccordancewiththerequirementsofBridgeSpecialprovisionBSP022604.

4.4.5 Isolation Bearings

Isolation bearingsmaybeusedforseismicretrofitprojectstoreducethedemandsthroughmodificationof thedynamicpropertiesofthebridgeasaviablealternativetostrengtheningweakelementsofnonductilebridgesubstructuremembersofexistingbridge.UseofisolationbearingsneedstheapprovalofWSDOTBridgeDesignEngineer.IsolationbearingsshallbedesignedpertherequirementoftheAASHTO Guide Specifications for Seismic Isolation.

Thedecisionforusingisolationbearingsshouldbemadeattheearlystageofprojectdevelopmentbasedonthecomplexityofbridgegeotechnicalandstructuraldesign.Acost‑benefitanalysiscomparingdesignwithstrengtheningweakelementsvs.designwithisolationbearingsshall beperformedandsubmittedforapproval.Thedesignerneedstoperformtwoseparatedesigns,onewithandonewithoutseismicisolationbearings.Thecost‑benefitanalysisshallatleastinclude:

• Higherinitialdesigntime andcomplexityofanalysis.


• Timerequiredforpreliminaryinvestigationandcorrespondenceswiththeisolationbearingsuppliers.

• Life‑cyclecostofadditionalandspecializedbearinginspection.

• Potentialcostimpactforbearingsandexpansionjointsreplacements.



Onceapprovalhasbeengivenfortheuseofseismicisolationbearing,thedesignershallsendasetofpreliminarydesignandspecificationrequirementstoatleastthreeseismic isolationbearingsuppliersforevaluationtoensurethattheycanmeetthedesignandspecificationrequirements.Commentsfromisolationbearingsuppliersshouldbeincorporatedbeforedesignofstructurebegins.SolesourceisolationbearingsuppliermaybeconsidereduponBridgeDesignOfficeandProjectEngineer'sofficeapproval.




4.5 Seismic Design Requirements for Retaining Walls4.5.1 General

Allretainingwallsshallincludeseismicdesignloadcombinations.ThedesignaccelerationforretainingwallsshallbedeterminedinaccordancewiththeAASHTO Guide Specifications for LRFD Seismic Bridge Design.Oncethedesignaccelerationisdetermined,thedesignershallfollowtheapplicabledesignspecificationrequirementslistedbelow:

Wall Types Design Specifications

Soldier Pile Walls With and Without Tie‑Backs

AASHTO LRFD Bridge Design Specifications

Pre‑Approved Proprietary Walls AASHTO LRFD Bridge Design Specifications or the AASHTO Standard Specifications for Highway Bridges‑ 17th Edition and 1,000 yr map design acceleration

Non‑Preapproved Proprietary Walls AASHTO LRFD Bridge Design Specifications

Standard Plan Geosynthetic Walls AASHTO LRFD Bridge Design Specifications

Non Standard Geosynthetic Walls AASHTO LRFD Bridge Design Specifications

Standard Plan Reinforced Concrete Cantilever Walls


Non Standard Non Proprietary Walls AASHTO LRFD Bridge Design Specifications

Soil Nail Walls AASHTO LRFD Bridge Design Specifications

Standard Plan Noise Barrier Walls AASHTO Guide Specifications for Structural Design of Sound Barriers – 1989 and Interims

Non‑ Standard Noise Barrier Walls Design per Chapter 3

Pre Approved and Standard Plan Moment Slabs for SE Walls and Geosynthetic Walls


Non‑Pre Approved and Non Standard Moment Slabs for SE Walls and Geosynthetic Walls


Non Standard Non Proprietary Walls, Gravity Blocks, Gabion Walls


ExceptionstothecasesdescribedabovemayoccurwithapprovalfromtheWSDOTBridgeDesignEngineerand/ortheWSDOTGeotechnicalEngineer.





4.99 ReferencesAASHTO LRFD Bridge Design Specifications,5thEdition,2010

AASHTO Guide Specifications for LRFD Seismic Bridge Design,2ndEdition,2011

AASHTOGudie Specifications for Seismic Isolation Design,3rdEdition,2010

CaltransBridge Design Aids14‑4JointShearModelingGuidelinesforExistingStructures,CaliforniaDepartmentofTransportation,August2008

FHWASeismic Retrofitting Manual for Highway Structures: Part 1‑Bridges,PublicationNo.FHWA‑HRT‑06‑032,January2006

Juirnarongrit,T.andAshfordS.A.,Effect of Pile Diameter on the Modulus of Subgrade Reaction,ReportNo.SSRP‑2001/22,UniversityofCalifornia,SanDiego,2005

McLean,D.I.andSmith,C.L.,Noncontact Lap Splices in Bridge Column‑Shaft Connections, ReportNunberWA‑RD417.1,WashingtonStateUniversity

Pender,M.J.,Discussionof"Evaluation of Pile Diameter Effects on Initial Modulus Subgrade Reaction".JournalofGeotechnicalandGeoenvirnonmentalengineering,ASCE,September2004.

WSDOTGeotechnical Design ManualM46‑03,EnvironmentalandEngineeringProgram,GeotechnicalServices,WashingtonStateDepartmentofTransportation

