National Steel Bridge Alliance

Steel: The Bridge Material of Choice

National Steel Bridge Alliance A division of the American Institute of Steel Construction

www.steelbridges.org

National Steel Bridge Alliance

Christopher Garrell, PE, LEED AP NSBA - Southeast Regional Director [email protected]

Kentucky Association of Professional Engineers Seminar

mailto:[email protected]�

National Steel Bridge Alliance Overview

• Supporting Designers and Owners throughout the Bridge Lifecycle.

NSBA Activities

Design

Planning Design

Operate

Management Maintenance

Build

Construction Fabrication

3 | www.steelbridges.org

NSBA Activities

NSBA

Steel Fabricators

Steel Producers Erectors Coatings

Producers Welding Industry

Design Community

Engineering Consultents Professors Students

Owners

State Highway Departments

County Highway

Departments

Federal Highway Authority

Toll Road Authorities


NSBA Regions

Northeast Bill McEleney

Cell: 401.965.6341

Email: [email protected]

Southeast Christopher Garrell, PE, LEED AP

Cell: 484.557.2949


West-Southwest Calvin R. Schrage

Cell: 402.440.3729



Material Availability Rolled Beams and Plate

Rolled Beam Availability

• Rolled beam generally more economical.

• Except with hard curve or camber.

• Availability dependent on rolling schedules.


Rolled Beam Availability

• Availability – NUCOR YAMATO - to 44” deep. – Gerdau Ameristeel - to 36” deep. – Steel Dynamics - to 36” deep. – 120’ long – max. – ASTM A992; ASTM A709, Gr. 50S

• Minimum Yield = 50 ksi • No HPS

• Allow plate girder alternate.


Mill Plate Availability


•Plate Availability Maximums


Producer Maximum Thickness (in)

Maximum Width (in)

Arcelor-Mittal 4 195

Nucor Steel 3 123

SSAB 3 120

EVRAZ 4 144


• Rationalize all mill plate tables


ArcelorMittal

Evraz

SSAB

Nucor


• Composite Mill Plate Tables


* A709-50 and A709-50W (Non-FC) Availability only.


** Refer to September 2011 issue of Modern Steel Construction Magazine.



• Thickness Increments

− 1/8” for plate up to 2 1/2” thick.

− 1/4” for plate over 2 1/2” thick.

• Width Preferences

− Fabricators prefer 72” and 96” widths.

− Cost increases with width.

Design Considerations Choices Affecting Cost

• Usable Plate Area

Design Considerations

Flange Plate Web Plate (Haunched)



• Usable Area – Web Plate

• Width: 1” – 4” • Length: 1” – 6” • Material loss will increase if web is haunched or cambered.

– Flange Plate • Width: 1” – 4” total plus an additional 1/4" per burn. • Length: 1”- 6” • A fabricator may choose to increase flange widths specified by

the Engineer from 1/4" - 3/8". – Can vary from fabricator to fabricator and can be

dependent on their capabilities and equipment.



• Girder Spacing - Wider is more economical. - A reduced number of girders (fewer linear feet) to be

detailed, fabricated, painted, transported, erected, inspected and maintained.

- Fewer diaphragms, crossframes and bearings. - MAYBE more pounds, but FEWER dollars.



• Girder Spacing - Use 10’ to 11’ with spans less than 140’. – Use 11’ to 14’ with spans greater than 140’. – Cost of thicker deck to accommodate wider spacing.

• Thicker deck may increase life.

• More dead load per girder may reduce vibration.

– Consider future redecking operations during preliminary design.


Girder Spacing




• Flange Shop Splices – No more than 2 shop slices. – Minimum change; 1/8” (to 2 ½” thick), 1/4”. – Maximum change; thinner piece at least 1/2 of thicker. – ONLY when material cost saved > labor cost spent. – Keep width constant (i.e., to change cross section area,

change thickness).


• Flange Sizing - change width

Bevel

Step 1: Bevel (4) Plate Edges

Fabricate 4 Flange Assemblies



Burn

Step 2: Burn 12 Pieces From 3 Plates




Step 3: Fit up and tack weld 4 flange assemblies




Step 4: Attach 16 run-off tabs

Run-off Tab




Step 5: Weld and grind 8 splices

Weld




Step 6: Turn over 4 flange assemblies




Step 7: Back gouge, weld and grind 8 butt joints

Weld




Step 8: Remove and grind 16 run-off tabs, taper wider plates




Bevel

Step 1: Bevel (4) and Taper (2) Plate Edges

• Flange Sizing - change thickness

Change Thickness

Taper



Step 2: Fit up and tack weld 3 plates




Step 3: Attach 4 run-off tabs

Run-off Tab




Step 4: Weld and grind 2 splices

Weld




Step 5: Turn over 1 piece




Step 6: Back gouge, weld and grind 2 butt welds

Weld




Step 7: Remove and grind 4 run-off tabs




Step 8: Burn 4 flanges from 1 assembly

Burn




Step 8: Burn 4 flanges from 1 assembly





• Flange Sizing – Width transitions increase labor for flange assemblies

up to 35%. – If you must change flange width, do so at bolted field

splice (do not clip corners of top flanges). – Allow fabricators to eliminate splices within a shipping

piece by carrying thicker material through to next designed splice location.



• Flange Sizing


More Information Online Sources

AASHTO/NSBA Steel Bridge Collaboration

G12.1 Design for Constructability

Modern Steel Construction

Steel Plate Availability for Highway Bridges


More Information

• NSBA Website – www.steelbridges.org – “Resources” – “AASHTO/NSBA Steel

Bridge Collaboration”

• MSC Magazine – www.modernsteel.com

More Information


http://www.steelbridges.org/�

http://www.modernsteel.com/�

LRFD Simon Software Solution for Preliminary Steel Bridge Design

• Key tool for efficient preliminary design and analysis of steel bridges.

• Made steel a more appealing material of choice from project inception.

• Validation for design and analysis calculation.

• Usage – Over 500 individual licenses. – 97 Government licenses including FHWA and DOTs. – 11 Colleges and Universities. – Basis of NSBA Design Studies.

• Right tool for the best material choice - steel.


LRFD Simon

• Collaboration with Wisconsin Department of Transportation.

• Analysis Core - Phase I – Update 4th Edition LRFD Specification to 5th Edition

LRFD Specification. – Work completed late 2011.

• User Interface – Phase II – Preliminary workflow and design completed. – Interim Beta releases to be made available. – Release Candidate (RC) scheduled for April with final

commercial release to follow.

LRFD Simon


• Modern Windows user interface.

• Workflow driven input.

• Corporate/Agency definable settings.

• Customizable output.

LRFD Simon


LRFD Simon

• 34 Delivered Examples – 1, 2, 3 and 4 Span Configurations. – Plate Girder and Box Girder.


• Google Group – Beta Release Information. – Product and Documentation Downloads. – Community Discussion Forum. – Invitation by Request.

LRFD Simon


• “Release Candidate” to be distributed at World Steel Bridge Symposium.

• Special session on design using LRFD Simon on Wednesday April 18.

• Visit www.steelbridges.org/wsbs for more information.

LRFD Simon


http://www.steelbridges.org/wsbs�

Thank you…

Christopher Garrell, PE, LEED AP NSBA - Southeast Regional Director [email protected]

mailto:[email protected]�

Documents

National Steel Bridge Alliance