TESTS AND ANALYSIS FOR COMPOSITE ACTION IN GLULAM BRIDGES

Studies are described that assess the feasibility and value of including the effects of composite behavior in the design of glulam bridges. Analytical and experimental work is presented for the verification of a mathematical model developed for this modern timber bridge system. Six (three southern pine and three Douglas fir) different reduced-scale double T-beams, which modeled glulam-bridge cross sections, were structurally tested in the working-load range and to failure. The specimens were constructed of glulam stringers that ranged in size from 7.6 x 53.3 cm (3 x 21 in) to 12.7 x 76.2 cm (5 1/8 x 30 in) and had a nominal span of 12.2 m (40 ft). Glulam deck panels 1.2 m (4 ft) wide provided a 7.9-x209-cm (3 1/8 x 82-in) flange. The mechanical fasteners consisted of steel dowels between panels and lag bolts to provide vertical anchorage into the stringers. Finite-element techniques were used in the verification of the theory and in the analytical evaluation of the test results. The major parameters affecting composite action were (a) discontinuities or gaps in the deck layer, (b) slip moduli or connector properties, and (c) the modulus of elasticity of the deck. Composite-action curves were generated to illustrate the effects of these parameters. These curves were further used to extrapolate the test results to full-size components, which leads to greater understanding of the incomplete composite behavior of the glulam bridge system. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; Photos; References;
  • Pagination: pp 1-8
  • Monograph Title: Bridge design, evaluation, and repair
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00195905
  • Record Type: Publication
  • ISBN: 0309028191
  • Files: TRIS, TRB
  • Created Date: Aug 15 1979 12:00AM