LOAD DISTRIBUTION ON HIGHWAY BRIDGES HAVING ADEQUATE TRANSVERSE DIAPHRAGMS

A SIMPLE-SPAN CONCRETE BRIDGE OVER ONEONTA CREEK ON THE COLUMBIA RIVER HIGHWAY WAS SELECTED FOR A FULL-SIZE INVESTIGATION TO DETERMINE THE LOAD DISTRIBUTION TO GIRDERS HAVING AN ADEQUATE DIAPHRAGM SYSTEM. THE WHEEL LOADS ARE DISTRIBUTED TO ADJACENT GIRDERS BY THE SLAB AS THOUGH IT WERE A SIMPLE BEAM. THESE LOADS DEFLECT THE GIRDERS AND A PART OF THE LOAD IS TRANSFERRED TO THE DIAPHRAGMS AT THEIR INTERSECTION WITH THE GIRDERS. SINCE THE DIAPHRAGM IS IN STATIC EQUILIBRIUM, THE LOAD TRANSFERENCE AT THE OUTSIDE GIRDERS MAY BE REGARDED AS REACTIONS AND AT THE INTERIOR GIRDERS AS LOADS, AND THE DEFLECTION CURVE OF THE DIAPHRAGM SET UP IN TERMS OF THE UNKNOWN LOAD-TRANSFER COEFFICIENT. THE LOAD TRANSFER DEPENDS ON THE RELATIVE STIFFNESS OF THE MEMBERS; WHETHER THE CONCRETE ACTS WITH THE STEEL IN RESISTING TENSION STRESSES (UNCRACKED SECTION) AND WHETHER THE CURBS AND SIDEWALKS ACT WITH THE EXTERIOR GIRDERS HAVE CONSIDERABLE EFFECT. THE TESTING WAS DONE BEFORE THE BRIDGE WAS OPENED TO GENERAL TRAFFIC, AND THE TEST RESULTS INDICATED THAT THE CONCRETE WAS EFFECTIVE IN TENSION AND THAT THE CURBS AND SIDEWALKS ACTED WITH THE EXTERIOR GIRDERS IN RESISTING STRESS.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrbresearchrpts/1952/14B-004.pdf
• Supplemental Notes:
  • 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.
• Corporate Authors:

  Highway Research Board (HRB)

  Washington, DC   
• Authors:
  • Paxson, G S
• Conference:
  • Thirty-First Annual Meeting of the Highway Research Board
• Publication Date: 1952

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Tables;
• Pagination: 12p
• Monograph Title: Distribution of load stresses in highway bridges
• Serial:
  • Highway Research Board Research Reports
  • Issue Number: 14B
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Bridge design; Bridges; Concrete bridges; Deflection; Diaphragms (Engineering); Girders; Highway bridges; Load tests; Load transfer; Structural design
• Old TRIS Terms: Diaphragms
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00209600
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jun 5 1972 12:00AM