WEB STRESSES IN PRESTRESSED CONCRETE BRIDGE BEAMS HAVING DISCONTINUOUS TENDONS

Prestressed concrete bridge girders are sometimes designed with prestressing tendons that terminate within the span rather than at the ends of the girders or at their supports. Tendons of this type are normally significantly inclined at their anchorages due to the clearances required for construction because of the inclination of the tendons at their anchorages. Significant vertical components of prestressing are imposed on the girder. The AASHTO Specifications for Highway Bridges and the Building Code Requirements for Reinforced Concrete (ACI 318-71) do not specify specific methods of analysis for this condition. A finite element analysis of an actual bridge girder was made to determine the conditions of stress in the vicinity of intermediate anchorages. The results of this analysis were compared to those obtained with a principal tensile stress analysis using methods normally employed by bridge designers. It was found both methods of analysis predicted principal tensile stresses of similar magnitude and orientation. The predicted locations of the greatest principal tensile stresses were different for the two methods of analysis. The fact that the greatest principal tensile stresses occur on planes approximately parallel to the paths of some of the post-tensioning ducts is demonstrated. /Author/

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 45-52
  • Monograph Title: Bridge Engineering. Volume 2
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00183779
  • Record Type: Publication
  • ISBN: 0309026970
  • Files: TRIS, TRB
  • Created Date: Dec 12 1978 12:00AM