LADOTD BRIDGE DESIGN AND EVALUATION MANUAL … Desi… · · 2016-03-15LADOTD BRIDGE DESIGN AND EVALUATION MANUAL (BDEM) Louisiana Transportation Conference 2/29/2016 Zhengzheng

LADOTD BRIDGE DESIGN AND EVALUATION MANUAL (BDEM)

Louisiana Transportation Conference

2/29/2016

Zhengzheng “Jenny” Fu, P.E.

Assistant Bridge Design Administrator LADOTD Bridge Design Section

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ACKNOWLEDGEMENTS

DOTD Staff

FHWA

Consultants

SDR Engineering Consultants, Inc. (Prime)

Huval and Associates (Sub)

All Users

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OUTLINE

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Overview of BDEM

Overview of BDTM.50

Highlights of BDEM Part II – Design Specifications

BDEM

Published on 11/17/2014 via BDTM.50

Posted on Bridge Design Website

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BRIDGE DESIGN WEBSITE http://wwwsp.dotd.la.gov/Pages/default.aspx

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http://wwwsp.dotd.la.gov/Pages/default.aspx

http://wwwsp.dotd.la.gov/Pages/default.aspx

BDEM Organization - Preface

Part I Policies and Procedures

Part II Design Specifications (Supplement

AASHTO Specifications)

Volume 1 - Bridge Design

Volume 2 - Movable Bridge Design

Volume 3 - Structural Supports for Permanent Highway Signs and High Mast Lighting

Volume 4 - Highway Safety

Volume 5 - Bridge Evaluation/Rating

Part III Design and Detail Aids

Part IV Background Information

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BDEM Revision History

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BDEM – Part I Policies and Procedures

CHAPTER 1 - BRIDGE DESIGN TECHNICAL MEMORANDA (BDTM)

2 - BRIDGE DESIGN COMMITTEES

3 - POLICY FOR QUALITY CONTROL AND QUALITY ASSURANCE (QC/QA)

4 - HIGHWAY BRIDGE PROGRAM AND LIGHTING PROGRAM

5 - GENERAL BRIDGE DESIGN GUIDELINES (to be developed)

6 - DESIGN POLICY FOR BRIDGE REHABILITATION/REPAIR PROJECTS

7 - PROJECT DELIVERY (to be developed)

8 - PLAN PREPARATION (to be developed)

9 - STANDARD PLANS AND SPECIAL DETAILS

10 – CONSULTANT CONTRACTING (to be developed)

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BDEM – Part II

Design Specifications (Supplement AASHTO Specifications and

use same format as AASHTO Specifications )

Volume 1 - Bridge Design Volume 2 – Movable Bridge Design

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BDEM – Part II

Volume 3 - Structural Supports for Permanent Highway Signs and High Mast Lighting

Volume 4 - Highway Safety

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BDEM – Part II

Volume 5 – Bridge Evaluation/Rating

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BDEM – Part III

Design and Detail Aids

CHAPTER 1 - LG GIRDER PRELIMINARY DESIGN CHARTS

2 - LADOTD DECK DESIGN TABLES

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BDEM – Part IV

Background Information

CHAPTER 1 - LADV-11 DEVELOPMENT

2 - TEMPERATURE RANGE STUDY

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BDTM.50

BDEM Organization

BDEM Format

Maintenance and Revisions

Revision History Table

Revision Date on Each Page

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BDTM.50

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Consultant Projects

Revisions before NTP - Implement

Revisions after NTP – Implement if no impact to scope and schedule; implement with approval if impact scope and schedule

In-House Projects (similar to Consultant Projects)

New AASHTO Editions or Interims

Implement via BDTM

BDTM.50

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Archived Manuals

Bridge Design English Manual (4th Edition)

Bridge Design Metric Manual

LRFD Bridge Design Manual

BDEM Archived Pages

Guidelines – Part of BDEM

Federal Aid Off-System Highway Bridge Program Guidelines

(Referenced in Part I, Chapter 4, Stand-Alone document )

Guide to Constructing, Operating, and Maintaining Highway Lighting System

(Referenced in Part I, Chapter 4, Stand-Alone document)

Policies and Guidelines for Bridge Rating and Evaluation

(Referenced in Part II, Volume 5, will be incorporated to BDEM)

BDTM.50

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Published BDTMs – Part of BDEM

(59) Published BDTMs

(21) have been incorporated in BDEM

BDTM index

BDEM Highlights Part II, Vol. 1 – Bridge Design

Chapter 1 - Introductions

1.1 – Bridges vulnerable to coastal storms

Construction Specifications

1.2 – New definitions

1.3 – Ductility, Redundancy, Operational Importance factors

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Chapter 2 - General Design and Location Features

2.2 New definitions

2.3.2.2 Traffic Safety (User and Structure Protections)

EDSMs - Guard Rails, Curbs, Sidewalks

Bridge Railings – Min. TL-4 (NCHRP 350 or MASH)

Sidewalks – ADA Standards, Min. 5’-0” Pedestrian, 6’-0” Bicycle

Geometric Stds – Min. Design Guidelines signed by Chief Engineer

EDSMs - R/W, SSD on Curve Bridges

Road Surface Slopes – Min. 2.5%

Vessel Collision Protections

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2.3.3 Clearances

Navigational, Highway Vertical and Horizontal, R/R Overpass

2.5.2.2 Inspectability

Design requirements and details for maintenance and inspection purpose

2.5.2.3 Maintainability

Min. vertical and horizontal clearances for bearing

maintenance and repair/replacement

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2.5.2.4 Rideability

New approach slab design policy (based on two LTRC research projects) to improve the bump at end of bridge

Standard lengths:

40’ (On-system fill), 20’ (On-system cut) and 10’ (off-system only)

Min. Thickness: 1’-6” (40’ and 20’) & 1’-0” (10’)

No more pile-supported approach slab (see commentary). Consult Geotechnical Engineer for project sites that need special attention in controlling settlement.

Standards are being developed for 40’, 20’ and 10’ slabs (See

BDTM.57 for more details) 21



2.5.5 Bridge Aesthetics

Emphasize the importance of bridge aesthetics and implementation of Context Sensitive Solutions (CSS)

2.6.6 Roadway Drainage

Deck drainage requirements

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BDEM Highlights Part II, Vol. 1 – Bridge Design Chapter 3 - Load and Load Factors

3.4.1 New Table 3.4.1-1 – Load Comb. And Load Factors

Incorporated Scour related extreme limit states (Extreme Event III-VI) based on NCHRP Report 489

Modified the live load factor for Extreme Event - I & Service - III

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3.5.1 New Table 3.5.1-1 – Unit Weights of Common Perm. Loads

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3.6.1.2 Design Vehicular Live Load: LADV-11 (see Part IV - Background Information, Chapter 1)

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C3.6.1.4.2 Typical example of determining ADTTSL over design life for Fatigue Load

3.6.4 Braking Forces –BR

Apply BR to substructure and bearing design

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3.10 Earthquake Effects – EQ

Preliminary seismic design information (see commentary for background):

Louisiana Seismic Site Class Map (based on 1984 geologic map of Louisiana)

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Louisiana Seismic Zone Map

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Louisiana Seismic Design Information Table

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3.12.2.1 New Design Temperature Range Table (see Part IV – Background Information, Chapter 2, based on Louisiana temp. data 2000-2012)

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3.14.1 Two Vessel Collision Events Defined for Extreme II and V

A Drifting Empty Barge

A Ship or Barge Tow under Normal Operation

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Chapter 4 – Structural Analysis and Evaluation

4.4 Pre-Approved Software List

Posted on Bridge Design Website under QC/QA

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BDEM Highlights Part II, Vol. 1 – Bridge Design Chapter 5 - Concrete Structures

5.4.3 Reinforcing Steel

Uncoated “black” bar, Grade 60, Grade 75 allowed for WWF only

Epoxy coated reinforcing not allowed

Requires approval for any type other than “black” bar

5.4.4 Prestressing Steel

0.6 in (preferred) and 0.5 in dia.

Grade 270 low relaxation bar (Stress-Relieved strand not allowed)

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5.6.3 Strut-and-Tie Model (STM)

STM should be used for situations that conventional beam theory does not apply.

Examples: deep beams, deep footings, hammerhead caps, near supports of pile and column bent caps, ends of

beams, etc.

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5.6.3 Strut-and-Tie Model (STM)

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5.7.3.4 Control of Cracking

dc ≤ 2”+ 1/2 bar dia.

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5.7.3.4 Control of Cracking

Environmental Exposure Map defines Class 2 (e) and

Severe Corrosive Conditions (Table 5.9.4.2.2-1)

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5.7.3.6.2 Deflection and Camber

Adopted PCI multiplier method

5.8.2.7 Maximum Spacing of Trans. Reinforcement Max. 12” for girders span existing or future traffic

lanes or R/R track and bent caps

5.8.3.4 Procedures for Determining Shear Resistance

Simplified Procedure 5.8.3.4.1 (=2, =45) allowed

General Procedure 5.8.3.4.2 (MCFT) allowed

Simplified Procedure 5.8.3.4.3 (Vci and Vcw) not allowed

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5.9.4.2.2 Tension Stresses

Defined regions in the Environmental Exposure Map to apply “Severe Corrosive Conditions” in Table 5.9.4.2.2-1

ADTT> 2500, tensile stress limit =

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5.12 Durability

LADOTD Strategy:

HPC with surface resistivity requirement (New Specifications)

Min. Concrete Cover (5.12.3)

Crack control (5.7.3.4)

14 days of water curing (New Specifications)

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All Structural Concrete Classes will be HPC with Surface

Resistivity requirement (New Standard Specifications)

New Structural Concrete Classes:

Class A1 and Mass A1 (CIP) - 4000 psi (50% pay)



Class S (Drilled Shaft and Seal) – 4000 psi (50% pay)

Class P1 (Precast Piles) - 6000 psi

Class P2 (Prestressed Girders) – 8500 psi (Standard)

Class P3 (Prestressed Girders) – 10,000psi (Requires Approval) 41


All Structural Concrete Classes will be HPC with Surface

Resistivity requirement (New Specifications)

Surface Resistivity/Permeability

>22 kΩ-cm (< 2000 Coulombs) 100% pay

20-21.9 kΩ-cm (2250 – 2000 Coulombs) 98% pay

18-19.9 kΩ-cm (2500 – 2250 Coulombs) 90% pay

<18 kΩ-cm (>2500 Coulombs) 50% pay or remove

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5.13.2.2 Diaphragms

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5.14.1.2 Precast Beams

AASHTO Type II, III, IV, BT-72, BT-78, Quad Beam

LG-25, LG-36, LG-45, LG-63, LG-72 and LG-78 (Allowed with Approval)

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Girder Maximum Span Length Table

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LG Girder Preliminary Design Tables – Part III, Chapter 1

Haunch Thickness

Limitation on using PPC girders in curved bridges

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Girder Stability Notes must be included in contract plans:

Contractor is responsible for stability of girders

Contractor is required to submit calculations and shop drawings to show all details for storage (dunnage), transportation, lifting and erection

EOR’s responsibility on girder stability during design process:

Ensure girders can be supported on dunnage within 3 feet from ends

Determine if the girders can be picked up in accordance with PCI Bridge Design Manual (follow the lateral stability example in PCI Manual)

Review Contractor’s calculations and shop drawings to ensure the proposed girder stability can be achieved within the allowable stress limits

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Chapter 6 – Steel Structures

6.4.1 Structural Steel

Grade 36, 50, 50W, HPS 50W, HPS 70 W

Grade HPS 100W (requires approval)

Use of unpainted weathering steel preferred

Use of painted steel requires approval

6.6.2 Fracture

All Fracture Critical Members shall be clearly identified on plans.

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6.10.1 Composite Sections

Composite section shall be used for all steel girder design.

Non-composite section is allowed in negative moment region with approval (6.10.1.2)

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6.10.10 Shear Connectors

The attachment method of shear connector to steel girders (Field weld or shop weld) should be contractor’s choice. Do not specify the method in plan.

However, designers shall ensure the attachment methods for shear connector are shown on steel girder shop drawings.

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Chapter 9 – Deck and Deck Systems

9.7 Concrete Deck Slabs

Overall Depth: 8”, 8.5”, 9”, 9.5” (including ½” sacrificial thickness)

7”, 7.5” (Movable bridge only)

Top cover: 2.5” (2” for movable bridge only)

Bottom cover: 1.5”

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9.7.2 Empirical Design

Not allowed

9.7.3 Traditional Design

LADOTD Deck Design Tables (Part III, Chapter 2)

Interior regions (overhang and its adjacent region need to be designed)

7” maximum rebar spacing

Doubly reinforced concrete theory is not allowed in deck design

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9.7.3.2 Distribution Reinforcement

Use the same distribution percentage for secondary reinforcement at top and bottom

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Future Work Part I – Policies and Procedures (Chapter 5, 7, 8)

Incorporate all valid information in archived manuals to BDEM

Part II, Volume 1 – Work with Geotechnical Section to incorporate all foundation design provisions (Chapter 10, 11 &12)

Part II Volume 5 – Incorporate the current rating guideline

Part III Chapter 1 - LG Standards/Bearing Pad Design Charts

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Future Work

Incorporate New Standard Specifications

Research Initiatives - Intermediate Diaphragm Study, Link Slab Study and Floating Span, Internal Curing Concrete, Integral Bridge, Wave Atlas Development for Louisiana Coastal Area

AASHTO SCOBS T-10 (Concrete Design) Technical Committee Chapter 5 Reorganization (Ballot in June 2016 in AASHTO SCOBS Annual Mtg.)

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Documents

LADOTD BRIDGE DESIGN AND EVALUATION MANUAL … Desi… · · 2016-03-15LADOTD BRIDGE DESIGN AND EVALUATION MANUAL (BDEM) Louisiana Transportation Conference 2/29/2016 Zhengzheng