Noncomposite concrete deck bracing effects on continuous steel stringer lateral torsional buckling resistance

Louisiana’s bridges used two-girder or truss systems in the 1950 s and 1960 s, in which floorbeams are carried by main members and continuous stringers are supported by the floorbeams. The main members are either two edge (fascia) girders or trusses. Continuous span stringer bottom flanges are in compression in their negative moment regions, which could result in lateral torsional buckling (LTB). When these stringers are load rated using AASHTOWare Bridge Ratingᵀᴹ analysis software, lateral torsional buckling (LTB) resistance is calculated in accordance with the AASHTO LRFD Bridge Design Specifications, which the authors have determined may not adequately account for bracing effects provided by a noncomposite deck, and therefore could underestimate the flexural strength. Resulting ratings may be low enough to require restrictive, and possibly unnecessary, load postings or even bridge closures. This issue affects more than 20 significant bridges that are key parts of Louisiana’s highway system. To address the challenge of underestimated stringer LTB resistance and assess bracing effects provided by a concrete deck, experimental and analytical studies were performed on a two-span, continuous, steel stringers in a grillage system, which included three stringer lines, an interior transverse support (floorbeam), and transverse diaphragms at the end supports. The tests encompassed a variety of configurations, with and without a concrete deck. This paper describes laboratory testing setups and discusses experimental results, focusing on bracing effects on LTB resistance due to the presence of a noncomposite concrete deck. Finite element models using ANSYS were calibrated, validated using test results and used to simulate stringer behavior in Louisiana’s representative bridges. Finite element analyses of various tests showed generally comparable results to test data, and provided a feasible approach to load rate continuous stringers if a refined analysis is deemed necessary. The studies showed that stringer LTB resistance could possibly be tripled when noncomposite deck bracing effects are considered.

• Record URL:
  • https://doi.org/10.1016/j.engstruct.2023.115886
• Record URL:
  • http://www.sciencedirect.com/science/article/pii/S0141029623003000
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/01410296
• Supplemental Notes:
  • © 2023 The Authors. Published by Elsevier Ltd. Abstract reprinted with permission of Elsevier.
• Authors:
  • Sun, C Shawn
  • Babarinde, Oluwatobi F
  • Kuruppuarachchi, Dinesha
  • Linzell, Daniel G
  • 0000-0002-7158-1776
  • Puckett, Jay A
  • 0000-0002-0834-7549
  • Akintunde, Emmanuel
  • 0000-0001-6569-2915
• Publication Date: 2023-5-15

Language

• English

Media Info

• Media Type: Web
• Features: Appendices; Figures; Illustrations; Photos; References; Tables;
• Pagination: 115886
• Serial:
  • Engineering Structures
  • Volume: 283
  • Issue Number: 0
  • Publisher: Elsevier
  • ISSN: 0141-0296
  • Serial URL: http://www.sciencedirect.com/science/journal/01410296

Subject/Index Terms

• TRT Terms: Bracing; Bridge decks; Buckling; Concrete bases; Finite element method; Stringers
• Identifier Terms: AASHTO LRFD Bridge Design Specifications; AASHTOWare Bridge Management; ANSYS (Computer program)
• Geographic Terms: Louisiana
• Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 01878057
• Record Type: Publication
• Files: TRIS
• Created Date: Mar 29 2023 4:48PM