Field verification for the effectiveness of continuity diaphragms for skewed continuous P/C P/S concrete girder bridges : tech summary.

Details

• Creators:
  Saber, Aziz ; Mothukuri, Ajay K. ; Arasangi, Prashant
• Corporate Creators:
  Louisiana Transportation Research Center
• Corporate Contributors:
  Louisiana. Dept. of Transportation and Development
• Subject/TRT Terms:
  • Diaphragms (Engineering)
  • Prestressed concrete bridges
  • Continuous girder bridges
  • Testing
  • Diaphragms (Structural engineering)--Testing
  • Prestressed concrete bridges--Testing
  • Continuous bridges.
• Publication/ Report Number:
  FHWA/LA.09/440
• Resource Type:
  Research Paper
• Geographical Coverage:
  Louisiana
• Edition:
  Tech summary.
• Corporate Publisher:
  Louisiana Transportation Research Center
• Abstract:
  The majority of highway bridges are built as cast-in-place reinforced concrete slabs and prestressed concrete ; girders. The simple-span precast, prestressed concrete girders made continuous through cast-in-place decks ; and diaphragms have been widely used in the United States since 1960’s. Shear connectors on the top of the ; girders assure composite action between the slabs and girders. The design guidelines for bridges in AASHTO ; Standard Design Specifi cations Section 8.12 indicate that diaphragms should be installed for T-girder spans ; and may be omitted where structural analysis shows adequate strength. Similar discussions are presented ; in Load Resistance Factor Design (LRFD) Bridge Design Code (AASHTO 2004). The advantages of continuity ; diaphragms are the reduced expansion joint installation and maintenance costs, the improved riding quality, ; and the enhanced structural redundancy. Furthermore, the eff ects of diaphragms are not accounted for in the ; proportioning of the girders. Therefore, the use of diaphragms should be investigated. ; In 2004, the Louisiana Transportation Research Center (LTRC) sponsored the ; theoretical investigation on the eff ects of continuity diaphragms for skewed ; continuous span precast prestressed concrete girder bridges. The results of the ; research were published in LTRC Report 383. The research team, Saber et al., ; reported that continuity diaphragms used in the prestressed girder bridges on ; skewed bents cause diffi culties in detailing and construction. Details for small ; skewed bridges (> 30° from perpendicular) have not been a problem for the ; Louisiana Department of Transportation and Development (LADOTD), but as ; the skew angle increases or the girder spacing decreases, the connection and the ; construction become more diffi cult. Also, results of the research indicated that ; the continuity diaphragms could be eliminated without any signifi cant eff ects ; on the stresses or defl ections in the bridge girders. One of the objectives of this ; research was to conduct fi eld verifi cation for the analytical results reported in ; LTRC Report 383.
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• Format:
  PDF
• Funding:
  LTRC Project No. 06-3ST ; State Project No. 736-99-1373
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18255/dot_18255_DS1.pdf
• File Type:
  [PDF - 129.77 KB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:fde74b4f42c40edd8911510c5acab525f398692dc5a51053ad72d7376dda3c6f