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:
  Continuous Bridges. Continuous Girder Bridges Diaphragms (Engineering) Diaphragms (Structural Engineering)--Testing Prestressed Concrete Bridges Prestressed Concrete Bridges--Testing Testing
• 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.
  
  
• Format:
  PDF
• Funding:
  LTRC Project No. 06-3ST ; State Project No. 736-99-1373
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:fde74b4f42c40edd8911510c5acab525f398692dc5a51053ad72d7376dda3c6f
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18255/dot_18255_DS1.pdf
• File Type:
  [PDF - 129.77 KB ]