ESTIMATION OF BENDING MOMENTS IN BOX-BEAM BRIDGES USING CROSS-SECTIONAL DEFLECTIONS

THIS REPORT DESCRIBES PART OF THE RESEARCH WORK CONDUCTED UNDER THE FRITZ LABORATORY PROJECT 322, ENTITLED A STRUCTURAL MODEL STUDY OF LOAD DISTRIBUTION IN HIGHWAY BRIDGES. THE PURPOSES OF THIS WORK WERE TO: (1) FIND AN ANALYTICAL CORRELATION BETWEEN THE TRANSVERSE DISTRIBUTIONS OF LONGITUDINAL BENDING MOMENTS AND THE CROSS-SECTIONAL DEFLECTIONS IN BOX-BEAMS BRIDGES, AND (2) DEVELOP A PRACTICAL METHOD FOR THE ESTIMATION OF BENDING MOMENTS IN BOX-BEAM BRIDGES BY THE USE OF CROSS-SECTIONAL DEFLECTIONS. TO EXPERIMENTALLY VERIFY THE PROPOSED METHOD, TEST RESULTS FROM SEVENTEEN SMALL SCALE (1/16) PLEXIGLAS BOX-BEAM BRIDGE MODELS ARE REPORTED. DETAILS OF THE FABRICATION, INSTRUMENTATION AND TESTING OF THE MODELS ARE REFERENCED. IN PARTICULAR, IT SHOULD BE NOTED THAT THESE SEVENTEEN PLEXIGLAS MODELS WERE TESTED UNDER STATIC VEHICULAR LOADS, USING THE CREEP COMPENSATING TECHNIQUE. AN ANALYSIS OF THE EXPERIMENTAL RESULTS AND A PROPOSED METHOD FOR ESTIMATING BENDING MOMENTS ARE PRESENTED. THE ESTIMATED VALUES EXHIBIT AGREEMENT WITH THE MODEL TEST RESULTS. THE CONTRIBUTION OF CURBS AND PARAPETS TO THE FLEXURAL STIFFNESS OF THE BRIDGE WAS TAKEN INTO ACCOUNT IN THE ANALYSIS. THE INFLUENCES ON THE CORRELATION BETWEEN BENDING MOMENTS AND CROSS-SECTIONAL DEFLECTIONS DUE TO CURBS, PARAPETS, DIAPHRAGMS, SIZE AND SPACING OF BEAMS, AND THICKNESS OF SLAB ARE DISCUSSED. THE PROPOSED METHOD WAS USED TO ESTABLISH BENDING MOMENTS IN ONE EXISTING BRIDGE. THE ESTIMATED VALUES WERE FOUND TO BE CLOSE TO THOSE OBTAINED IN THE FIELD TEST. AS A RESULT OF THIS INVESTIGATION, IT IS BELIEVED THAT THE USE OF MEASURED DEFLECTIONS, ALONG WITH THE GEOMETRIC PROPERTIES OF THE CROSS-SECTION, MAY ENABLE AN ECONOMICAL AND ACCURATE ESTIMATION OF THE LATERAL LOAD DISTRIBUTION IN PRESTRESSED CONCRETE BOX-BEAM BRIDGES. /AUTHOR/

• Supplemental Notes:
  • Rpt No 322.2, 114 PP, 28 FIG, 36 TAB, 19 REF
• Corporate Authors:

  Lehigh University

  Bethlehem, PA  United States  18015
• Authors:
  • Macias, RENDON MA
  • Fang, S
  • VanHorn, D A
• Publication Date: 1968-6

Subject/Index Terms

• TRT Terms: Bending moments; Box beams; Deflection; Distributions (Statistics); Estimates; Highway bridges; Load transfer; Static loads
• Uncontrolled Terms: Model tests; Transverse distribution
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00208946
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 21 1994 12:00AM