Initial investigation of reinforced concrete filled tubes for use in bridge foundations.

Details

• Creators:
  Roeder, Charles ; Lehman, Dawn
• Corporate Creators:
  Washington State Transportation Center
• Corporate Contributors:
  Washington (State). Dept. of Transportation. Research Office ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Bridge Foundations Bridges Bridge Substructures Caissons Concrete Concrete Filled Tubes Connections Piles (Supports) Structural Connection Tubing
• Publication/ Report Number:
  WA-RD 776.1
• Resource Type:
  Tech Report
• Geographical Coverage:
  Washington
• Edition:
  Research report.
• Corporate Publisher:
  Washington (State). Dept. of Transportation. Office of Research and Library Services
• Abstract:
  The Washington State Department of Transportation (WSDOT) frequently employs deep pile or caisson bridge
  
  foundations for its bridge structures. Deep pile and drilled shaft foundations are increasingly important for seismic
  
  design in Washington state, because of increased seismic design load demands in bridge design specifications. A
  
  common caisson is a reinforced concrete filled tube caisson. Although these types of foundation elements are
  
  common, there are few guidelines on their design. As a result, current WSDOT design methods are conservative
  
  and neglect the many benefits provided by composite action of the concrete and the steel tube, which may result in
  
  increased cost and size of the foundation. Recent research on composite concrete filled steel tubes (CFT) shows
  
  significant benefit for applications using CFT elements, in particular that CFT elements can develop more lateral
  
  resistance and greater inelastic deformation capacity with less deterioration of resistance than reinforced concrete
  
  elements of the same weight and diameter. Hence the use of this composite action permits smaller diameter and
  
  shorter caisson foundations resulting in cost savings associated with a smaller piles and drilled shafts, less material
  
  and reduced construction time and cost. This research involves consideration of the composite properties of CFT
  
  members with internal reinforcement, and this special case of internally reinforced CFT is identified as RCFT in
  
  this report.
  
  The research study used analytical tools verified using past experimental and analytical research on CFT
  
  members and foundation connections without internal reinforcement. The research included comprehensive review
  
  of past research results including experiments and analysis of CFT and RCFT elements and connections. Design
  
  models were evaluated and compared to prior test results to determine their accuracy and reliability. A
  
  comprehensive analytical study was performed to extend this prior research to current WSDOT RCFT applications.
  
  The analytical studies were calibrated to past experimental results to document their accuracy, and the analysis
  
  included development of basic design models, fiber or section based analysis, and detailed continuum based models.
  
  No experiments were included in this initial study, but observations from prior experimental research were to be
  
  used to support the work. The goals of this preliminary study were to develop initial answers to uncertainly in the
  
  design process of these components and their connections to permit the WSDOT to begin to employ the benefits of
  
  composite action for these sub-structural systems. To that end, specific design recommendations from this
  
  preliminary research study are provided. Finally, an overview of the additional research needed to further develop
  
  the deep foundation system is provided.
  
  
• Format:
  PDF
• Funding:
  Agreement T4118, Task 58
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:3106e7c9bc32e80ed1f951915751f3b1601f86b72a6fc0ab10f4b1213cc552c6
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/24435/dot_24435_DS1.pdf
• File Type:
  [PDF - 3.01 MB ]