EFFECTS OF DIAPHRAGMS IN BRIDGES WITH PRESTRESSED CONCRETE I-SECTION GIRDERS

THE RESULTS OF A STUDY OF THE EFFECTS OF THE NUMBER, STIFFNESS, AND LOCATIONS OF DIAPHRAGMS IN MULTI-BEAM, SIMPLY SUPPORTED, RIGHT HIGHWAY BRIDGES ARE PRESENTED. THE PARAMETERS STUDIED ALSO INCLUDED THE RELATIVE GIRDER STIFFNESS, H, THE RATIO OF GIRDER SPACING TO SPAN, B/A, THE GIRDER TORSIONAL STIFFNESS, THE GIRDER SPACING, AND THE LOCATION OF THE LOADS RELATIVE TO THE EDGE GIRDERS OF THE STRUCTURE. THE BEHAVIOR OF THE BRIDGES IS EVALUATED FOR SEVERAL TYPES OF LOADINGS, INCLUDING SINGLE LOADS AND GROUPS OF LOADS. THE BRIDGES STUDIED WERE DIVIDED INTO THREE GENERAL CATEGORIES ACCORDING TO THE UNIFORMITY OF LOAD DISTRIBUTION TO THE GIRDERS, AND DESIGN RECOMMENDATIONS REGARDING DIAPHRAGM ARRANGEMENTS AND STIFFNESSES MADE. IN MOST STRUCTURES IN WHICH THE OUTER LINE OF WHEELS CAN FALL DIRECTLY OVER THE EDGE GIRDERS, DIAPHRAGMS SHOULD NOT BE USED, AS THEY WILL INCREASE THE CONTROLLING MOMENT IN THE BRIDGE. IN OTHER CASES, DIAPHRAGMS MAY BE EITHER HELPFUL OR HARMFUL, AND CRITERIA ARE DEVELOPED FOR DESIGN PURPOSES. THE INFLUENCE OF THE NUMBER OF DIAPHRAGMS WAS STUDIED, AND THE EFFECTS OF A SINGLE MIDSPAN DIAPHRAGM AND TWO DIAPHRAGMS LOCATED NEAR MIDSPAN WERE ABOUT THE SAME, STRUCTURALLY, THOUGH THE COST EFFECTIVENESS OF THE SINGLE DIAPHRAGM IS BETTER. /AUTHOR/

• Corporate Authors:

  Illinois Department of Transportation

  Division of Highways, 2300 South Dirksen Parkway
  Springfield, IL  United States  62764

  University of Illinois, Urbana-Champaign

  Urbana, IL  United States  61801

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Sithichaikasem, S
  • Gamble, W L
• Publication Date: 0

Subject/Index Terms

• TRT Terms: Beams; Bridge design; Bridge superstructures; Bridges; Concrete bridges; Design; Diaphragms (Engineering); Load transfer; Prestressed concrete; Prestressing; Structural design
• Uncontrolled Terms: Bridge spans
• Old TRIS Terms: Concrete bridge structures; Design combinations; Diaphragms
• Subject Areas: Bridges and other structures; Design; Highways;

Filing Info

• Accession Number: 00208035
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: Study No Ihr-93
• Files: TRIS, USDOT
• Created Date: Mar 27 1972 12:00AM