Evaluating the Variations in Use of Steel Intermediate Diaphragms for Precast Concrete Girder Bridges throughout the United States

Intermediate diaphragms are used in precast concrete girder bridges for three primary reasons: 1) to prevent torsional girder rotations during girder erection and deck placement operations; 2) to increase the vertical load distribution between girders; and 3) to transfer and spread an impact load from an overheight vehicle to adjacent girders. Typical practice includes the design of end diaphragms, but there is significant variation in the practice of specifying or requiring intermediate diaphragms between state transportation agencies. Wide variations exist in the acceptance of steel alternates to traditional cast-in-place concrete. In addition to the lack of cohesion in material choice, there is also significant variation in the type and geometry of steel intermediate diaphragms, spacing within the span, and alignment relative to the girder. The importance of intermediate bracing in a span during construction is widely accepted as essential; however, their contribution to a bridge in service, after the bridge deck has hardened, is considered by some to be very minimal. As part of this research, a detailed survey of design practices by individual state bridge design agencies throughout the United States was conducted for all 50 states. To the authors knowledge this is the first effort to successfully profile the use of intermediate diaphragms in all 50 states.


  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 540-551
  • Monograph Title: Structures Congress 2014

Subject/Index Terms

Filing Info

  • Accession Number: 01522718
  • Record Type: Publication
  • ISBN: 9780784413357
  • Files: TRIS, ASCE
  • Created Date: Apr 9 2014 3:01PM