BRIDGE DESIGN BY THE AUTOSTRESS METHOD
The Autostress method has been evolving as an extension to the AASHTO Load-Factor method for rolled-beam and plate-girder steel highway bridges. The Autostress method uses the same three load levels as the Load-Factor method: Service load, Overload, and Maximum Load. However, to satisfy the structural performance requirements, the Autostress method injects two new concepts into bridge design: mechanism formation at Maximum Load and shakedown at Overload. When a structure forms a mechanism, there are sufficient plastic hinges to cause failure. When a structure shakes down, residual stresses and residual moments are automatically developed and assure elastic behavior under subsequent loading--hence the term Autostress. Although results of both methods for a simple span are the same, the Autostress method provides economies in continuous-span bridges; it utilizes the same safety factor against mechanism formation in both simple-span and continuous-span bridges. As part of an AISI-sponsored project, nine Load-Factor bridges were redesigned according to the Autostress method; the average cost saving was 10.7 percent. The objective of the AISI project is to suggest that the Autostress method be incorporated into the AASHTO specification after experimental verification. /Author/
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309026962
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Supplemental Notes:
- This paper appeared in Transportation Research Record No. 664, Bridge Engineering, Volume 1. Proceedings of a conference conducted by the Transportation Research Board, September 25-27, 1978. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Authors:
- Carskaddan, Phillip S
- Haaijer, Geerhard
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Conference:
- Bridge Engineering Conference, 1st, 1978, St Louis, Missouri, USA
- Location: St Louis Missouri, United States
- Date: 1978-9-25 to 1978-9-28
- Publication Date: 1978
Media Info
- Media Type: Print
- Features: Figures; References; Tables;
- Pagination: pp 255-261
- Monograph Title: Bridge Engineering. Volume 1
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Serial:
- Transportation Research Record
- Issue Number: 664
- Publisher: Transportation Research Board
- ISSN: 0361-1981
Subject/Index Terms
- TRT Terms: Beams; Bridge design; Bridge superstructures; Bridges; Design; Failure; Girder bridges; Load factor; Metal bridges; Oversize loads; Plate girders; Specifications; Steel bridges; Stresses; Structural analysis; Structural design
- Uncontrolled Terms: Bridge spans; Design criteria; Overloads
- Old TRIS Terms: Rolled beam
- Subject Areas: Bridges and other structures; Design; Highways;
Filing Info
- Accession Number: 00183772
- Record Type: Publication
- ISBN: 0309026962
- Files: TRIS, TRB
- Created Date: Dec 12 1978 12:00AM