Table Of Content

FM3-34.343 (FM5-446) Military Nonstandard Fixed Bridging HEADQUARTERS, DEPARTMENT OF THE ARMY DISTRIBUTION RESTRICTION: Approved for public relase; distribution is unlimited. *FM 3-34.343 (FM 5-446) FieldManual Headquarters No.3-34.343 DepartmentoftheArmy Washington,DC,12 February 2002 Military Nonstandard Fixed Bridging Contents Page PREFACE.................................................................................................................vii PART ONE BASIC CONSIDERATIONS Chapter1 BACKGROUNDINFORMATION........................................................................... 1-1 GeneralConcepts................................................................................................... 1-2 BridgeDesign......................................................................................................... 1-4 ArmyFacilitiesComponentsSystem...................................................................... 1-4 ClassificationInformation........................................................................................ 1-5 EngineerResponsibilities........................................................................................ 1-6 SupportingInformation............................................................................................ 1-6 Chapter2 RECONNAISSANCEANDPRELIMINARYINVESTIGATIONS............................ 2-1 HastyReconnaissance........................................................................................... 2-1 DeliberateReconnaissance.................................................................................... 2-1 RepairorReconstruction........................................................................................ 2-1 New-BridgeConstruction........................................................................................ 2-2 SiteRequirements.................................................................................................. 2-3 SurveyControl........................................................................................................ 2-6 SurveyDrawings..................................................................................................... 2-6 PART TWO CLASSIFICATION, REINFORCEMENT AND REPAIR, AND POSTING Chapter3 CLASSIFICATION.................................................................................................. 3-1 SectionI-Bridge-ClassificationConsiderations............................................... 3-2 SectionII-ExpedientClassification................................................................... 3-2 DISTRIBUTIONRESTRICTION:Approvedforpublicrelease;distributionisunlimited. *This publication supersedes FM 5-446, 3 June 1991.. i FM3-34.343 Page HastyMethod......................................................................................................... 3-2 TrackCommander’sBridge-CrossingBooklet....................................................... 3-3 SectionIII-Correlation-CurveClassification.................................................... 3-3 Correlation-CurveApplications............................................................................... 3-8 BridgeCondition..................................................................................................... 3-8 SpanLength........................................................................................................... 3-8 Correlation-CurveUses...........................................................................................3-9 SectionIV-AnalyticalBridgeClassification................................................... 3-10 ClassificationAssumptions................................................................................... 3-10 MomentClassificationforSimpleSpans.............................................................. 3-15 MomentClassificationforContinuousSpans....................................................... 3-16 Roadway-WidthClassificationandClearanceRestrictions.................................. 3-18 Solid-SawnandGlue-LaminatedTimber-StringerBridges.................................. 3-18 Steel-StringerBridges.......................................................................................... 3-22 Composite-StringerBridges................................................................................. 3-26 Steel-GirderBridges............................................................................................. 3-29 TrussBridges....................................................................................................... 3-46 ReinforcedConcreteSlabBridges....................................................................... 3-55 ReinforcedConcreteT-BeamBridges................................................................. 3-59 ReinforcedConcreteBox-GirderBridges............................................................. 3-64 PrestressedConcreteBridges............................................................................. 3-65 ArchBridges......................................................................................................... 3-74 MovableBridges................................................................................................... 3-81 SuspensionBridges............................................................................................. 3-82 OtherBridges....................................................................................................... 3-83 Chapter4 REINFORCEMENTANDREPAIR......................................................................... 4-1 BasicConsiderations.............................................................................................. 4-1 HastyorEmergencyRepairs................................................................................. 4-4 StringerSupports................................................................................................... 4-7 StringerReinforcement.......................................................................................... 4-9 SteelFloor-BeamReinforcement......................................................................... 4-11 TrussReinforcementandRepair......................................................................... 4-11 FlooringRepair..................................................................................................... 4-17 Masonry-Pierand-AbutmentRepair.................................................................... 4-18 Masonry-Arch-BridgeRepair................................................................................ 4-20 Chapter5 POSTING............................................................................................................... 5-1 Bridge-ClassificationSigns......................................................................................5-1 TrafficControls....................................................................................................... 5-5 ii FM3-34.343 Page PART THREE DESIGN Chapter6 BRIDGESUPERSTRUCTURES............................................................................ 6-1 DesignPhases........................................................................................................ 6-1 DesignSequence.................................................................................................... 6-1 Chapter7 SUBSTRUCTUREDESIGN................................................................................... 7-1 AbutmentDesignProcedure................................................................................... 7-1 AbutmentDesigns................................................................................................. 7-12 Intermediate-SupportDesign................................................................................ 7-34 Chapter8 SUSPENSION-BRIDGEDESIGN.......................................................................... 8-1 Descriptions............................................................................................................ 8-1 BridgeSites............................................................................................................. 8-2 DesignFactors........................................................................................................ 8-3 LiveLoad................................................................................................................ 8-4 Panels......................................................................................................................8-4 Suspenders............................................................................................................. 8-8 MainCables............................................................................................................ 8-9 Backstays.............................................................................................................. 8-13 Towers.................................................................................................................. 8-13 Anchorages........................................................................................................... 8-16 Chapter9 CONNECTIONS..................................................................................................... 9-1 TimberConnections.................................................................................................9-1 SteelConnections................................................................................................... 9-9 Chapter10 CONSTRUCTION................................................................................................. 10-1 PlanningProcess.................................................................................................. 10-1 MaterialPreparation,TimberFraming.................................................................. 10-9 MaterialPreparation,SteelFabrication................................................................. 10-9 Safety.................................................................................................................. 10-11 Erection-EquipmentCapacity............................................................................. 10-12 SpecialEquipment.............................................................................................. 10-13 Truck-andCrawler-MountedCranes.................................................................. 10-13 Derricks............................................................................................................... 10-14 Cableways.......................................................................................................... 10-14 Hoists.................................................................................................................. 10-14 Jacks................................................................................................................... 10-14 Falsework............................................................................................................ 10-15 Erection-EquipmentTechniques......................................................................... 10-15 iii FM3-34.343 Page DerrickElevation................................................................................................ 10-19 SpecialLaunchingMethods(SteelErection)..................................................... 10-22 Precautions........................................................................................................ 10-27 Suspension-BridgeConstruction........................................................................ 10-29 Chapter11 INSPECTIONANDMAINTENANCE................................................................... 11-1 Inspection............................................................................................................. 11-1 Maintenance......................................................................................................... 11-5 Chapter12 BRIDGINGINARCTICANDSUBARCTICENVIRONMENTS........................... 12-1 Permafrost............................................................................................................ 12-1 Transportation...................................................................................................... 12-2 ThawEffects......................................................................................................... 12-3 Explosives............................................................................................................ 12-3 Steel..................................................................................................................... 12-4 Wood.................................................................................................................... 12-4 Concrete............................................................................................................... 12-4 EngineerEquipment............................................................................................. 12-4 ConstructionSchedules....................................................................................... 12-4 BridgeFoundationsandSubstructures................................................................ 12-4 NativeMaterials.................................................................................................... 12-6 FoundationSurvey............................................................................................... 12-7 IntermediateSupports.......................................................................................... 12-8 Abutments.......................................................................................................... 12-10 IceRemoval....................................................................................................... 12-12 SuperstructurePrinciples................................................................................... 12-14 Panel-TrussBridges........................................................................................... 12-14 Timber-TrussBridges......................................................................................... 12-14 Steel-TrussBridges............................................................................................ 12-14 Fords.................................................................................................................. 12-14 IceCrossings...................................................................................................... 12-16 ExpedientIce-BridgeConstruction..................................................................... 12-18 ExpedientIce-BridgeReinforcementandRepair............................................... 12-19 AppendixA CONVERSIONCHARTS.......................................................................................A-1 AppendixB VEHICLECLASSIFICATION.................................................................................B-1 HypotheticalVehicles..............................................................................................B-1 StandardClassificationCurves............................................................................ B-14 AnalyticalClassificationProcedure...................................................................... B-14 iv FM3-34.343 Page ExpedientClassificationProcedure..................................................................... B-20 Vehicle-ClassificationSigns................................................................................. B-20 AppendixC TIMBERPROPERTIES......................................................................................... C-1 Civilian-DesignStress.............................................................................................C-1 Military-DesignStress.............................................................................................C-1 AppendixD STEELPROPERTIES........................................................................................... D-1 All-PurposeSteel................................................................................................... D-1 High-Strength,Low-AlloySteel.............................................................................. D-1 Quench-andTempered-AlloySteel....................................................................... D-1 SteelStrengths...................................................................................................... D-2 StructuralShapes...................................................................................................D-2 Unlisted-BeamsSectionProperties..................................................................... D-12 AppendixE STRUCTURALMECHANICS................................................................................ E-1 Dead,Live,andImpactLoads............................................................................... E-1 Stresses................................................................................................................. E-1 StaticEquilibrium................................................................................................... E-6 InternalReactions.................................................................................................. E-8 ShearandMomentDiagrams.............................................................................. E-10 AppendixF CLASSIFICATIONEXAMPLES............................................................................ F-1 Notations................................................................................................................ F-1 Timber-StringerBridge........................................................................................... F-4 Steel-StringerBridge.............................................................................................. F-8 CompositeSteel-ConcreteStringerBridge.......................................................... F-11 Steel-GirderBridge.............................................................................................. F-17 TrussBridge......................................................................................................... F-24 ReinforcedConcrete-SlabBridge........................................................................ F-31 ReinforcedConcreteT-BeamBridge................................................................... F-35 ReinforcedConcrete-Box-GirderBridge.............................................................. F-39 PrestressedConcreteBridge............................................................................... F-43 Masonry-ArchBridge........................................................................................... F-48 AppendixG CONCRETEPROPERTIES................................................................................... G-1 GeneralProperties................................................................................................. G-1 CementTypes........................................................................................................ G-2 Mass-ConcreteStructures..................................................................................... G-4 Steel-ReinforcedConcrete..................................................................................... G-4 v FM3-34.343 Page AppendixH SOILPROPERTIES...............................................................................................H-1 AppendixI SUPERSTRUCTUREDESIGNEXAMPLES.......................................................... I-1 Notations................................................................................................................. I-1 Timber-StringerSuperstructurewithaTimberDeck............................................... I-3 Steel-StringerSuperstructurewithaConcreteDeck............................................... I-9 Glossary ...................................................................................................................Glossary-1 Bibliography ............................................................................................................Bibliography-1 Index .........................................................................................................................Index-1 vi Preface This manual provides essential technical information on nonstandard fixed bridges for engineer staff officers. It is the doctrinal source of information for the United States (US) Army on the North Atlantic Treaty Organization (NATO) Bridge and Vehicle Classification System. This manualalso providesvariousmethods for classifyinganddesigning nonstandard fixed bridges in militarytheatersofoperation(TOs). This manual provides detailed technical data on the classification (analysis) and design of bridges.ItisNOTintendedtoreplacecivilianclassificationoranalysiscodesandproceduresand should NOT be used for civilian construction or classification. Engineer officers should note that the methods shown in this manual are for conservative classification and design. Qualified engineersalsomightuseappropriatecivilianmethodsformilitaryclassificationanddesign. AppendixAcontainsanEnglish-to-metricmeasurementconversionchart. The proponent for this publication is HQ TRADOC. Send comments and recommendations on Department of the Army (DA) Form 2028 directly to the US Army Engineer School (USAES), Attention: ATSE-DOT-DD, Directorate of Training, 320Maneuver Support Center (MANSCEN) Loop,Suite336,FortLeonardWood,Missouri65473-8929. The provisions of this publication are the subject of the following international standardization agreements (STANAGs) and Quadripartite STANAG (QSTAG):STANAG2010 Engineer (ENGR) (Edition5), STANAG2021 ENGR (Edition5), STANAG2101 Land Force Tactical Doctrine and OperationalProcedures(TOP)(Edition10),andQSTAG180(Edition4). Unless this publication states otherwise, masculine nouns and pronouns do not refer exclusively tomen. Thispublicationcontainscopyrightedmaterial. vii FM3-34.343 Page viii PART ONE Basic Considerations A bridge is a structure that is erected over obstacles such as a river or other watercourse, a chasm, or a railroad to make a passageway from one bank to the other. A bridge is usually constructed of wood, stone, brick, concrete, steel, or iron. This book identifies methods and procedures for performing bridge reconnaissance, vehicle and bridge classification, and analytical design of superstructures and substructures; constructing bridge connections; and repairing or reinforcing existing bridges. Reconnaissance is critical to any military operation and for analyzing existing and potential bridge sites. Information must be gathered for bridge use and construction that might normally be overlooked. The engineer and reconnaissance elements must be knowledgeable and prepared for the mission. Proper vehicle and bridge classification is also an important engineer responsibility that helps keep lines of communication (LOC) through the preservation of existing bridges in the TOs. The purpose of bridge reconnaissance is to collect data that is necessary to support operationalplanningandmovement.Existingbridgesareinspectedtodeterminetheir load-carrying capacity and the requirement for repair and reinforcement. The alternatives might revolve around the erection of a new semipermanent bridge or the repair of a damaged permanent structure. When a demolished bridge is to be replaced, reconnaissance should include a report of the serviceability of structural members and accessories, which might be useful for the contemplated construction. ThischapterimplementsSTANAGs2010(Edition5) and2021(Edition5)andQSTAG180(Edition4). Chapter 1 Background Information Rapid movement on the battlefield requires existing road networks or natural high-speed avenues that cross an assortment of wet and dry gaps. Many existing bridges in the TOs will adequately support military loads and only need to be classified for safe use. Gap crossings might be needed where none currently exist. Reinforcing or repairing a bridge can serve tactical purposes; however,mobility of the force is the key issue. BackgroundInformation 1-1