FULL-SCALE BRIDGE TESTING - AN EVALUATION OF BRIDGE DESIGN CRITERIA

FOUR DECK GIRDER HIGHWAY BRIDGES IN TENNESSEE, LOCATED IN AN AREA TO BE INUNDATED AS A PART OF A TENNESSEE VALLEY AUTHORITY RESERVOIR, WERE TESTED UNDER THE ACTIONS OF THREE TYPES OF LOADING: (1) VIBRATORY LOADING INDUCED BY FHWA VIBRATION GENERATING EQUIPMENT, (2) ROLLING LOADS SIMULATING AN HS20 LOADING WITH ADDITIONAL LOADS UP TO 132,000 POUNDS, AND (3) STATIC TESTS TO FAILURE. THE RESEARCH WAS DIRECTED TOWARD THE EVALUATION OF DESIGN CRITERIA RELATED TO THREE FACETS OF BRIDGE DESIGN: (1) LATERAL DISTRIBUTION OF LOADS, (2) DYNAMIC RESPONSE, AND (3) ULTIMATE STRENGTH AND MODE OF FAILURE. A CONSIDERATION OF TEST RESULTS PERMITS THE FOLLOWING CONCLUSIONS TO BE DRAWN: (1) THE LOAD DISTRIBUTION FACTORS OBTAINED WERE FOUND TO BE IN REASONABLY CLOSE AGREEMENT WITH THOSE OBTAINED IN OTHER SIMILAR STUDIES. (2) THE LATERAL DISTRIBUTION OF LOAD WAS FOUND TO BE PRACTICALLY INDEPENDENT OF LOAD LEVEL FOR ALL LOAD LEVELS UP TO YIELD OF THE STEEL. (3) AN ANALYTICAL METHOD, BASED ON STRAIN COMPATIBILITY RELATIONSHIPS AND ASSUMING THE ENTIRE BRIDGE WITH CURBS TO ACT AS A WIDE BEAM, PREDICTED THE ULTIMATE CAPACITY OF THREE OF THE FOUR BRIDGES WITHIN NINE PERCENT. EACH OF THESE THREE BRIDGES FAILED IN A FLEXURAL MODE. COMPOSITE ACTION WAS LOST IN THE PRESTRESSED CONCRETE BRIDGE PRIOR TO FLEXURAL FAILURE, AND SHEAR FAILURE OF THE TWO INTERIOR PRECAST SECTIONS OCCURRED AT A LOAD LEVEL LESS THAN THAT REQUIRED TO PRODUCE FLEXURAL FAILURE. (4) ULTIMATE LOADS CALCULATED ON THE BASIS OF AASHO SPECIFICATIONS WERE SOMEWHAT LOWER IN EACH CASE THAN THE ACTUAL ULTIMATE LOADS. IT APPEARS THAT COMPUTATION METHODS BASED ON AASHO SPECIFICATIONS GIVE A LOWER BOUND TO THE ACTUAL ULTIMATE LOAD FOR EACH BRIDGE. (5) THE LOAD CAUSING "FIRST PERMANENT SET" IS LESS READILY IDENTIFIABLE, EITHER THEORETICALLY OR EXPERIMENTALLY, THAN IS THE ULTIMATE LOAD. THE METHOD GIVEN IN THE AASHO SPECIFICATIONS FOR LIMITING OVERLOAD ON THE BASIS OF FIRST PERMANENT SET APPEARS TO BE REASONABLE. /FHWA/

• Supplemental Notes:
  • 177 PP
• Corporate Authors:

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • BURDETTE, E G
  • Goodpasture, D W
• Publication Date: 1971-12-31

Subject/Index Terms

• TRT Terms: Breaking loads; Bridge design; Bridges; Design; Dynamic loads; Failure; Highway bridges; Load tests; Load transfer; Structural design
• Uncontrolled Terms: Design criteria; Dynamic response
• Subject Areas: Bridges and other structures; Design; Highways;

Filing Info

• Accession Number: 00208048
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Files: TRIS, USDOT
• Created Date: Jun 28 1972 12:00AM