LATERAL DISTRIBUTION OF VEHICULAR LOADS IN A PRESTRESSED CONCRETE BOX-BEAM BRIDGE

THIS REPORT DESCRIBES THE FIELD TESTING OF ONE OF FIVE BEAM-SLAB HIGHWAY BRIDGES INCLUDED IN AN INVESTIGATION OF LATERAL DISTRIBUTION OF VEHICULAR LOADS IN PRESTRESSED CONCRETE SPREAD BOX-GIRDER BRIDGES. THE TEST SUPERSTRUCTURE CONSISTED OF FOUR HOLLOW PRESTRESSED CONCRETE BOX GIRDERS, EACH 36 INCHES WIDE BY 42 INCHES DEEP, A COMPOSITE, CAST-IN- PLACE REINFORCED CONCRETE SLAB, AND CAST-IN-PLACE CONCRETE CURB AND PARAPET SECTIONS. THE SPACING OF THE GIRDERS WAS NINE FEET, AND THE SIMPLY SUPPORTED TEST SPAN WAS 66 FEET 1-5/8 INCHES IN LENGTH. TWO CROSS-SECTIONS WERE GAGED FOR THE MEASUREMENT OF SURFACE STRAINS AND DEFLECTIONS, AND THE DATA WERE COLLECTED THROUGH USE OF CONTINUOUS RECORDING EQUIPMENT. THE LOAD VEHICLE WAS A 3-AXLE TRUCK LOADED TO SIMULATE THE AASHO HS20-44 DESIGN VEHICLE. THE STRUCTURAL RESPONSE DESCRIBED WAS PRODUCED BY CRAWL RUNS OF THE TEST VEHICLE, TRAVELLING ACROSS THE BRIDGE AT 2-3 MPH IN EACH OF FIVE PRESCRIBED LANES. THE PRINCIPAL OBJECTIVES WERE (1) TO DEVELOP INFORMATION ON LATERAL DISTRIBUTION OF THE VEHICLE LOADS TO THE GIRDERS, (2) TO COMPARE THE DISTRIBUTION AT TWO DIFFERENT CROSS-SECTIONS, (3) TO EVALUATE THE DEFLECTIONS AND ROTATIONS OF THE GIRDERS AT MIDSPAN, (4) TO EVALUATE THE STRAINS ON THE BOTTOM SURFACE OF THE MIDSPAN DIAPHRAGMS, (5) TO COMPARE THE RESULTS WITH SIMILAR RESULTS OBTAINED FROM THE TESTS OF THE BERWICK AND DREHERSVILLE BRIDGES, AND (6) TO COMPARE THE EXPERIMENTALLY BASED DISTRIBUTION FACTORS WITH VALUES USED IN THE DESIGN OF THE BRIDGE. ON THE WHITE HAVEN BRIDGE, THE EXPERIMENTALLY BASED DISTRIBUTION FACTORS WERE: (1) FOR INTERIOR GIRDERS, CONSIDERABLY LESS THAN THE DESIGN VALUE, AND (2) FOR EXTERIOR GIRDERS, SIGNIFICANTLY GREATER THAN THE DESIGN VALUE. THIS BEHAVIOR CLOSELY PARELLELS THAT OF THE BERWICK AND DREHERSVILLE BRIDGES, AND REFLECTS THE INCREASE IN STIFFNESS OF THE EXTERIOR GIRDERS RESULTING FROM THE CONTRIBUTION OF THE CURB AND PARAPET SECTIONS. THERE WAS NOT A SIGNIFICANT DIFFERENCE BETWEEN EXPERIMENTALLY DETERMINED DISTRIBUTION FACTORS AT THE TWO GAGED CROSS-SECTIONS. THE RATIOS OF EXPERIMENTAL TO DESIGN VALUES FURTHER INDICATE THAT: (1) FOR INTERIOR GIRDERS, A FACTOR OF THE S/K FORM IS APPROPRIATE, ALTHOUGH K SHOULD BE GREATER THAN THE 5.5 DESIGN VALUE, AND (2) FOR EXTERIOR GIRDERS, THE DESIGN PROCEDURE DOES NOT YIELD RESULTS CONSISTENT WITH ACTUAL BEHAVIOR. /AUTHOR/

• Supplemental Notes:
  • Rpt No 315.7, 84 PP, 24 FIG, 18 TAB, 19 REF
• Corporate Authors:

  Lehigh University

  Bethlehem, PA  United States  18015
• Authors:
  • GUILFORD, A A
  • VanHorn, D A
• Publication Date: 1968-8

Subject/Index Terms

• TRT Terms: Box girders; Bridge design; Bridges; Cast in place structures; Deflection; Field tests; Girder bridges; Load tests; Load transfer; Motion; Motor vehicles; Prestressed concrete; Reinforced concrete; Slabs; Spacing; Strain (Mechanics); Structural design
• Uncontrolled Terms: Lateral loads; Moving vehicles
• Old TRIS Terms: Strains
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00208945
• Record Type: Publication
• Files: TRIS
• Created Date: Apr 21 1994 12:00AM