FIELD TESTING OF HORIZONTALLY CURVED STEEL GIRDER BRIDGES

THE TEST RESULTS INDICATE THAT THE CURVED BRIDGE ANALYSIS PROGRAM USED BY THE N.Y.S.D.O.T. IS A RELIABLE TOOL FOR PREDICTING DEFLECTION AND IN-PLANE BENDING STRESSES DUE TO STATIC LOADS ON CURVED GIRDERS. THE PROGRAM IDEALIZES THE STRUCTURE AS A PLANAR GRID AND USES THE STIFFNESS METHOD OF ANALYSIS. GRAPHICAL INTERPOLATION WAS UTILIZED TO OBTAIN VALUES AT THE INSTRUMENTED SECTIONS. WHILE THE STRESS DUE TO NORMAL BENDING AVERAGED LESS THAN 60 PERCENT OF THE DESIGN WORKING STRESS, EXCLUDING DYNAMIC EFFECTS, THE STRESS DUE TO LATERAL FLANGE BENDING, ALTHOUGH UNDERTERMINABLE WITH THE PRESENT PROGRAM, WAS FOUND TO BE SIGNIFICANT AND COULD EXCEED THE ALLOWABLE BENDING STRESS AT SOME LOCATIONS. IT IS THEREFORE DESIRABLE TO DEVELOP A METHOD WHICH WOULD INCLUDE THESE FORCES. THE CURRENT WHEEL LOAD DISTRIBUTION PROVISIONS UTILIZED BY AASHO FOR STRAIGHT GIRDERS ARE INAPPROPRIATE FOR CURVED GIRDERS. IT IS HOPED THAT SIMPLE RELATIONSHIPS INCLUDING SUCH FACTORS AS CENTRAL ANGLE, RADIUS OF CURVATURE AND NUMBER OF GIRDERS, AS WELL AS GIRDER SPACING, CAN BE DEVELOPED TO DETERMINE WHEEL LOAD AND DEAD LOAD DISTRIBUTION FACTORS FOR HORIZONTALLY CURVED BRIDGES. A DEFINITE VARIATION HAS APPEARED IN THE EFFECTIVE WIDTH OF THE COMPOSITE CONCRETE DECK WITH TRANSVERSE POSITION OF LIVE LOAD. THE TREND OF THIS VARIATION SUGGESTS AN INCREASE IN EFFECTIVE WIDTH OF THE COMPOSITE SLAB AS LOAD ON THE GIRDER INCREASES. ALTHOUGH THIS EFFECT RESULTS IN SIZABLE VARIATIONS IN NEUTRAL AXIS LOCATION, THE CHANGE IN SECTION MODULUS, AND THUS THE INDUCED STRESS PER UNIT APPLIED MOMENT, IS SMALL. THEREFORE, NO CHANGE IN DESIGN METHOD IS REQUIRED. /AUTHOR/

• Corporate Authors:

  New York State Department of Transportation

  1220 Washington Avenue
  Albany, NY  United States  12232

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Beal, D B
  • Kissane, R J
• Publication Date: 0

Subject/Index Terms

• TRT Terms: Bending; Bending stress; Bridge decks; Composite structures; Concrete; Curves (Geometry); Deflection; Field tests; Forecasting; Girder bridges; Load transfer; Static loads; Steel; Stiffness; Stresses; Wheel loads; Width
• Uncontrolled Terms: Horizontal curvature; Wheel load distribution
• Old TRIS Terms: Stiffness methods (Structural)
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00208000
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 8 1971 12:00AM