2010 AASHTO BRIDGE COMMITTEE AGENDA ITEM PDF
Preview 2010 AASHTO BRIDGE COMMITTEE AGENDA ITEM
2010 AASHTO BRIDGE COMMITTEE AGENDA ITEM: 1 SUBJECT: Manual for Bridge Evaluation, Section 1, Article C1.4 TECHNICAL COMMITTEE: T-18 Bridge Management, Evaulation and Rehabilitation REVISION ADDITION NEW DOCUMENT DESIGN SPEC CONSTRUCTION SPEC MOVABLE SPEC MANUAL FOR BRIDGE SEISMIC GUIDE SPEC COASTAL GUIDE SPEC EVALUATION OTHER DATE PREPARED: 12/07/09 DATE REVISED: AGENDA ITEM: Add the following paragraph after the last paragraph in Article C1.4: Further information and details regarding QC/QA for Bridge Inspection can be found in NCHRP 20-07(252), Guidelines for Implementing Quality Control and Quality Assurance for Bridge Inspection. OTHER AFFECTED ARTICLES: None BACKGROUND: NCHRP 20-07(252), Guidelines for Implementing Quality Control and Quality Assurance for Bridge Inspection was published in 2009. This report documents both QC and QA practices that are presently implemented in the United States. The report serves as a resource for bridge owners that are developing, improving and/or implementing QC/QA practices. ANTICIPATED EFFECT ON BRIDGES: Gives a reference document to bridge owners. Implementation NCHRP report guidance may improve bridge inspection practice. REFERENCES: None OTHER: None 1 2010 AASHTO BRIDGE COMMITTEE AGENDA ITEM: 2 SUBJECT: Manual for Bridge Evaluation: Section 6, Table of Contents TECHNICAL COMMITTEE: T-18 Bridge Management, Evaluation and Rehabilitation REVISION ADDITION NEW DOCUMENT DESIGN SPEC CONSTRUCTION SPEC MOVABLE SPEC MANUAL FOR BRIDGE SEISMIC GUIDE SPEC COASTAL GUIDE SPEC EVALUATION OTHER DATE PREPARED: 01/31/10 DATE REVISED: AGENDA ITEM: Revise the Table of Contents as follows: Section 6: Load Rating TABLE OF CONTENTS 6.1 Scope---------------------------------------------------------------------------------------------6-1 6.1.1 Assumptions----------------------------------------------------------------------------- 6.1.2 Condition of Bridge Members-------------------------------------------------------- 6.1.3 Evaluation Methods-------------------------------------------------------------------- 6.1.4 Bridges with Unknown Structural Components----------------------------------- 6.1.5 Component Specific Evaluations---------------------------------------------------- 6.1.5.1 Decks------------------------------------------------------------------------- 6.1.5.2 Substructures---------------------------------------------------------------- 6.1.6 Evaluation of Complex Structures------------------------------------------------- 6.1.7 Nonredundant Structures----------------------------------------------------------- 6.1.8 Qualifications and Responsibilities------------------------------------------------ 6.1.9 Documentation of Load Rating---------------------------------------------------- PART A - LOAD AND RESISTANCE FACTOR RATING 6A.1 INTRODUCTION............................................................................................................ 6A.1.1 General ........................................................................................................ 6A.1.2 Scope .............................................................................................................. … 6A.1.3 Philosophy..................................................................................................... 2 6A.1.4 Assumptions................................................................................................................. 6A.1.5 Application of AASHTO LRFD Bridge Design Specifications..................................... 6A.1.6 Evaluation Methods....................................................................................................... 6A.1.7 Load and Resistance Factor Rating................................................................................ 6A.1.7.1 Design Load Rating.......................................................................................... 6A.1.7.2 Legal Load Rating........................................................................................... 6A.1.7.3 Permit Load Rating.......................................................................................... 6A.1.8 Component-Specific Evaluation................................................................................... 6A.1.8.1 Decks ............................................................................................................... 6A.1.8.2 Substructures................................................................................................... 6A.1.9 Evaluation of Complex Structures................................................................................. 6A.1.10 Qualifications and Responsibilities.............................................................................. 6A.1.11 Documentation of Load Rating ………………………………………………………… 6A.2 LOADS FOR EVALUATION...................................................................................................... 6A.2.1 General........................................................................................................................... 6A.2.2 Permanent Loads and Load Factors............................................................................... 6A.2.2.1 Dead Loads: DC and DW................................................................................ 6A.2.2.2 Permanent Loads Other than Dead Loads: P.................................................. 6A.2.2.3 Load Factors.................................................................................................... 6A.2.3 Transient Loads............................................................................................................. 6A.2.3.1 Vehicular Live Loads (Gravity Loads): LL...................................................... 6A.2.3.2 Applications of Vehicular Live Load.............................................................. 6A.2.3.3 Dynamic Load allowance: IM.......................................................................... 6A.2.3.4 Pedestrian Live Loads: PL............................................................................... 6A.2.3.5 Wind Loads: WL and WS................................................................................. 6A.2.3.6 Temperature Effects: TG and TU..................................................................... 6A.2.3.7 Earthquake Effects: EQ................................................................................... 6A.2.3.8 Creep and Shrinkage: CR and SH................................................................... 6A.3 STRUCTURAL ANALYSIS........................................................................................................... 6A.3.1 General.......................................................................................................................... 6A.3.2 Approximate Methods of Structural Analysis............................................................... 6A.3.3 Refined Methods of Analysis........................................................................................ 6A.3.4 Analysis by Field Testing.............................................................................................. 6A.4 LOAD-RATING PROCEDURES.................................................................................................... 3 6A.4.1 Introduction................................................................................................................... 6A.4.2 General Load-Rating Equation...................................................................................... 6A.4.2.1 General................................................................................................................... 6A.4.2.2 Limit States............................................................................................................ 6A.4.2.3 Condition Factor: φ .............................................................................................. c 6A.4.2.4 System Factor: φ ............................................................................................... s 6A.4.3 Design-Load Rating ..................................................................................................... 6A.4.3.1 Purpose ................................................................................................................ 6A.4.3.2 Live Loads and Load Factors .............................................................................. 6A.4.3.2.1 Live Load .............................................................................................. 6A.4.3.2.2 Live-Load Factors ................................................................................ 6A.4.3.3 Dynamic Load Allowance ................................................................................... 6A.4.4 Legal Load Rating ....................................................................................................... 6A.4.4.1 Purpose ................................................................................................................ 6A.4.4.2 Live Loads and Load Factors ............................................................................... 6A.4.4.2.1 Live Loads ............................................................................................ 6A.4.4.2.1a Routine Commercial Traffic............................................................ 6A.4.4.2.1b Specialized Hauling Vehicles.......................................................... 6A.4.4.2.2 Live-Load Factors ................................................................................ 6A.4.4.2.3 Generalized Live-Load Factors: γ ...................................................... L 6A.4.4.2.3a Generalized Live-Load Factors for Routine Commercial Traffic.... 6A.4.4.2.3b Generalized Live-Load Factors for Specialized Hauling Vehicles. 6A.4.4.3 Dynamic Load Allowance: IM .............................................................................. 6A.4.4.4 Rating in Tons ...................................................................................................... 6A.4.5 Permit Load Rating ...................................................................................................... 6A.4.5.1 Background .......................................................................................................... 6A.4.5.2 Purpose.................................................................................................................. 6A.4.5.3 Permit Types.......................................................................................................... 6A.4.5.3a Routine (Annual) Permits...................................................................... 6A.4.5.3a Special (Limited Crossing) Permits ...................................................... 6A.4.5.4 Live Load and Load Factors ................................................................................. 6A.4.5.4.1 Live Load ............................................................................................. 6A.4.5.4.2 Load Factors.......................................................................................... 4 6A.4.5.4.2a Routine (Annual) Permits .............................................................. 6A.4.5.4.2b Special (Limited-Crossing) Permits ................................................ 6A.4.5.5 Dynamic Load Allowance: IM .............................................................................. 6A.4.5.6 Exterior Beams ..................................................................................................... 6A.4.5.7 Continuous Spans ................................................................................................. 6A.5 CONCRETE STRUCTURES ......................................................................................................... 6A.5.1 Scope ...................................................................................................................... 6A.5.2 Materials .................................................................................................................. 6A.5.2.1 Concrete .................................................................................................. 6A.5.2.2 Reinforcing Steel ..................................................................................... 6A.5.2.3 Prestressing Steel ..................................................................................... 6A.5.3 Resistance Factors ........................................................................................................ 6A.5.4 Limit States .................................................................................................................. 6A.5.4.1 Design-Load Rating .............................................................................................. 6A.5.4.2 Legal Load Rating and Permit Load Rating ......................................................... 6A.5.4.2.1 Strength Limit State .............................................................................. 6A.5.4.2.2 Service Limit State ............................................................................... 6A.5.4.2.2a Legal Load Rating ......................................................................... 6A.5.4.2.2b Permit Load Rating ....................................................................... 6A.5.5 Assumptions for Load Rating .................................................................................... 6A.5.6 Maximum Reinforcement ............................................................................................ 6A.5.7 Minimum Reinforcement ............................................................................................. 6A.5.8 Evaluation for Flexural and Axial Force Effects .......................................................... 6A.5.9 Evaluation for Shear .................................................................................................... 6A.5.10 Secondary Effects from Prestressing ......................................................................... 6A.5.11 Concrete Bridges with Unknown Reinforcement ....................................................... 6A.5.12 Temperature, Creep, and Shrinkage Effects .............................................................. 6A.5.13 Rating of Segmental Concrete Bridges....................................................................... 6A.5.13.1 Scope................................................................................................................... 6A.5.13.2 General Rating Requirements.............................................................................. 6A.5.13.3 Application of Vehicular Live Loads................................................................... 6A.5.13.4 Design Load Rating............................................................................................. 6A.5.13.5 Service Limit State ............................................................................................. 6A.5.13.5.1 Legal Load Rating............................................................................... 5 6A.5.13.5.2 Permit Load Rating.............................................................................. 6A.5.13.6 System Factor: φ................................................................................................. s 6A.5.13.7 Evaluation for Shear and Torsion ....................................................................... 6A.6 STEEL STRUCTURES ................................................................................................................. 6A.6.1 Scope ........................................................................................................................... 6A.6.2 Materials ...................................................................................................................... 6A.6.2.1 Structural Steels .................................................................................................... 6A.6.2.2 Pins ...................................................................................................................... 6A.6.2.3 Wrought Iron ........................................................................................................ 6A.6.3 Resistance Factors ........................................................................................................ 6A.6.4 Limit States .................................................................................................................. 6A.6.4.1 Design-Load Rating .............................................................................................. 6A.6.4.2 Legal Load Rating and Permit Load Rating ......................................................... 6A.6.4.2.1 Strength Limit State .............................................................................. 6A.6.4.2.2 Service Limit State ................................................................................ 6A.6.5 Effects of Deterioration on Load Rating ...................................................................... 6A.6.6 Tension Members ........................................................................................................ 6A.6.6.1 Links and Hangers ................................................................................................ 6A.6.6.2 Eye Bars ............................................................................................................... 6A.6.7 Non-Composite Compression Members ...................................................................... 6A.6.8 Combined Axial Compression and Flexure ................................................................. 6A.6.9 I-Sections in Flexure ................................................................................................... 6A.6.9.1 General.................................................................................................................. 6A.6.9.2 Composite Sections .............................................................................................. 6A.6.9.3 Non-Composite Sections ...................................................................................... 6A.6.9.4 Encased I-Sections ...……………..…………………..………..…............…… 6A.6.9.5 Cross-Section Proportion Limits .…………………..………..………............... 6A.6.9.6 Riveted Members ………..…………………..………..………………………. 6A.6.9.7 Diaphragms and Cross-Frames ………………………………………………… 6A.6.10 Evaluation for Shear ….……………..………..……………………..………..…………........ 6A.6.11 Box Sections in Flexure ...………..………..……………………..………..……………........ 6A.6.11.1 Diaphragms and Cross-frames …………………………………………………........ 6A.6.12 Evaluation of Critical Connections ………..……………………..………..…………........ 6A.6.12.1 General ...……………... ………..……………………..………..…………………........ 6 6A.6.12.2 Bearing-Type Connections .……..………...…………..………..…………………......... 6A.6.12.3 Slip-Critical Connections …...…..……………………..………..…………………….... 6A.6.12.4 Pinned Connections ………...…..……………………..………..……………………..... 6A.6.12.5 Riveted Connections …… .……..……………………..………..……………………..... 6A.6.12.5.1 Rivets in Shear ...……..……………………..………..……………………..... 6A.6.12.5.2 Rivets in Shear and Tension ……………..………..……………………...... 6A.7 WOOD STRUCTURES ………………………….…………………………...……...……………......... 6A.7.1 Scope …………..…………………….…………………………………...……….……….... 6A.7.2 Materials ..…….……………………….…………………………………...……….….…........ 6A.7.3 Resistance Factors .………………….…………………………………...…………..…......... 6A.7.4 Limit States .….……………………….…………………………………...………..………..... 6A.7.4.1 Design-Load Rating ...…………….………………………………...………..……...... 6A.7.4.2 Legal Load Rating and Permit Load Rating ...……………………...………..………... 6A.7.5 Dynamic Load Allowance .…………….………………………………...………..…….. 6A.7.6 Evaluation of Critical Connections …....………………………………...………..…….. 6A.8 POSTING OF BRIDGES ... …………………………………………………...……...………………... 6A.8.1 General …………………………. …….………………………………...………..……. 6A.8.2 Posting Loads ..…………………. …….………………………………...………..……... 6A.8.3 Posting Analysis ..………………. …….………………………………...………..……... 6A.8.4 Regulatory Signs .………………. ……….………………………………...………..……... 6A.8.5 Speed Limits …. ..………………. ……….………………………………...………..…….. 6A.9 SPECIAL TOPICS ... …………………………………………………...……...……………….. 6A.9.1 Evaluation of Unreinforced Masonry Arches …………………………...………..…………. 6A.9.1.1 General ……..………………….………………………………...………..…….. 6A.9.1.2 Method of Analysis ……………. …….………………………………...………..…….. 6A.9.1.3 Allowable Stresses in Masonry…. ……….……………………………...………..….... 6A.9.2 Historic Bridges ………………………….……………………………...………..………....... PART B - ALLOWABLE STRESS RATING AND LOAD FACTOR RATING 6B.1 GENERAL ………………. ………………………………………………………….... 6B.1.1 Assumptions……………………………………………………………..………. 6B.1.2 Substructure Consideration………………….…………………………..….……. 6B.1.3 Safety Criteria………………………………….………………………..….……. 7 6B.1.4 Application of Standard Design Specifications ………………………..….…….. 6B.1.5 Nonredundant Structures …………………………………………………….….. 6B.1.6 Load Rating for Complex Structures …………..……………………………..….. 6B.2 QUALIFICATIONS AND RESPONSIBILITIES…………………………………..… 6B.3 RATING LEVELS…………………………………………………………………..… 6B.3.1 Inventory Rating Level…………………………………………………………..…. 6B.3.2 Operating Rating Level…………………………………………………….………. 6B.4 RATING METHODS………………………………………………………………. 6B.4.1 Allowable Stress (AS) …………………………………………………………….. 6B.4.2 Load Factor (LF) …… …………………………………………………………….. 6B.5 RATING EQUATION…………………………………………………….……………… 6B.5.1 General …………………………………………………………………………….. 6B.5.2 Allowable Stress……………………..………………………………….………….. 6B.5.3 Load Factor ……………………………………………………….……………….. 6B.5.4 Condition of Bridge Members ………………………………….………………….. 6B.5.5 Bridges with Unknown Structural Components …….………….………………….. 6B.6 NOMINAL CAPACITY (C) ……………………………………………………………..… 6B.6.1 General ………………………………………………………………………….….. 6B.6.2 Allowable Stress Method ……………………………………………………….….. 6B.6.2.1 Structural Steel ………………………………………………………….. 6B.6.2.1.1 Combined Stresses …….…………………………………. 6B.6.2.1.2 Batten Plate Compression Members…………………..….. 6B.6.2.2 Wrought Iron…………………………………………………………….. 6B.6.2.3 Reinforcing Steel ………………………………………………….…….. 6B.6.2.4 Concrete ….……………………………………………………….…….. 6B.6.2.4.1 Bending …………………………………………….…….. 6B.6.2.4.2 Columns ………………………………………………….. 6B.6.2.4.3 Shear (Diagonal Tension) …………………………….….. 6B.6.2.5 Prestressed Concrete ………………………………………………...….. 6B.6.2.6 Masonry …………………………………………………………….…... 6B.6.2.7 Timber ……………. ………………………………………………….... 6B.6.3 Load Factor Method ……………………………………………………………….. 6B.6.3.1 Structural Steel ……. ………………………………………………….. 6B.6.3.2 Reinforced Concrete ………………….……………………………….. 8 6B.6.3.3 Prestressed Concrete ………………………………………………….. 6B.7 LOADINGS ……………………………………………………………………….. 6B.7.1 Dead Load (D) ……………………………………………………………………. 6B.7.2 Rating Live Load …………………………………………………………………. 6B.7.2.1 Wheel Loads (Deck) …………………………………………………… 6B.7.2.2 Truck Loads ……… …………………………………………………… 6B.7.2.3 Lane Loads ………. ………………….………………………………… 6B.7.2.4 Sidewalk Loadings ..………………….………………………………… 6B.7.2.5 Live Load Effects (L) …………………………………………………… 6B.7.3 Distribution of Loads ………….………………………………………………….. 6B.7.4 Impact (I) …………... …………………………………………………………….. 6B.7.5 Deflection ………….. …………………………………………………………….. 6B.7.6 Longitudinal Loads … …………………………………………………………….. 6B.7.7 Environmental Loads ……………………………………………………………… 6B.7.7.1 Wind …………………………………………………………………….. 6B.7.7.2 Earthquake ..…………………………………………………………….. 6B.7.7.3 Thermal Effects ..……………………………………………………….. 6B.7.7.4 Stream Flow …………………………………………………………….. 6B.7.7.5 Ice Pressure …………………………………………………………….. 6B.7.7.6 Permanent Loads Other Than Dead Loads ……………………………. 6B.8 DOCUMENTATION OF RATING …………………………………………………………. 6B.9 POSTING OF BRIDGES ……………………………………………………………………. 6B.9.1 General …………………………………………………………………………….. 6B.9.2 Posting Loads ….………………………………………………………………….. 6B.9.3 Posting Analysis .………………………………………………………………….. 6B.9.4 Regulatory Signs ………………………………………………………………….. 6B.9.5 Speed Limits ..…………………………………………………………………….. 6B.10 PERMITS …………………………………………………………………………………. 6B.10.1 General ……………………………………………………………………………. 6B.10.2 Routine Permits ……………………………………………………………………. 6B.10.3 Controlled Permits ...………………………………………………………………. 6B.10.4 Escorted Permits ..…………………………………………………………… 9 OTHER AFFECTED ARTICLES: Portions of Section 6 will need to be renumbered to coincide with the new section headings. If this item passes this will be done prior to the interim being published. BACKGROUND: The Manual for Bridge Evaluation (MBE) combines into a single Section 6 provisions for Load and Resistance Factor Rating (LRFR) method (Part A) from the Manual for Condition Evaluation and Load and Resistance Factor Rating of Highway Bridges and the Allowable Stress and Load Factor rating methods (Part B) from the Manual for Condition Evaluation of Bridges (MCE). The LRFR and ASR/LFR Specifications in Section 6 have many articles that are independent of the load rating method and should therefore be identical. Items 1 through 12 include articles have been pulled out of Part A and Part B into a common section in front of Section 6. This would avoid conflicts, provide consistency between the Specifications, eliminate potential confusion, and reduce future editing effort. Items 13 through 35 pertain to revisions to or deletions of related Articles in Part A and Part B on account of their inclusion in the new up front section. Refer to 2010 Agenda Item 3. ANTICIPATED EFFECT ON BRIDGES: Clarifies load rating requirements that apply equally to all load rating methods. This modification to the articles will make Part A and Part B load rating provisions consistent. REFERENCES: None OTHER: None 10
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