Effect of implementing lean-on bracing in skewed steel I-girder bridges.

Details

• Creators:
  Bechtel, Andrew
• Corporate Creators:
  The College of New Jersey
• Corporate Contributors:
  City University of New York. University Transportation Research Center
• Subject/TRT Terms:
  Bracing Girder Bridges Lean-on Bracing Skew Bridges Steel Bridges Steel I-Girder
• Resource Type:
  Tech Report
• Geographical Coverage:
  New Jersey
• Corporate Publisher:
  City College of New York. University Transportation Research Center
• Abstract:
  Skew of the supports in steel I-girder bridges cause undesirable torsional effects, increase cross-frame forces, and generally increase the difficulty of designing and
  
  constructing a bridge. The girders experience differential deflections due to the skewed supports, and undesirable effects arise when the girders are linked transversely.
  
  Before the placement of the deck, the main method of linking the girders transversely is through the use of cross-frames. The cross-frames are designed to provide
  
  stability during construction and distribute transverse loads through the bridge girders; this is their primary role. Cross-frames also help control differential displacement
  
  during deck placement and distribute vertical loads in the bridge’s elastic and inelastic ranges. The cross-frames are not specifically designed for these tasks; these are the
  
  secondary roles of the cross-frames. Lean-On bracing has been proposed to reduce skew effects caused by traditional cross-frames. While having been shown to improve
  
  skew effects, the alternative cross-frame designs have not been evaluated on the effect they have on the cross-frames’ secondary roles.
  
  This paper describes a study of the effects Lean-On bracing has on the secondary roles of cross-frames. Three-dimensional Finite Element Models were used to perform a
  
  study involving changes in skew angle and cross-frame design. The rotation of the girders, maximum cross-frame stresses, load distribution, and differential displacement
  
  between the girders were used to characterize the behavior of the bridges. For the bridge type studied, the only major difference in performance was that the maximum
  
  cross-frame stresses were reduced for the bridges modeled with Lean-On bracing.
  
  
• Format:
  PDF
• Funding:
  49198-21-27
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:f84064aa2852dca18139d82241537deb70a35a93dff676dfadd2e0563b422a38
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/31704/dot_31704_DS1.pdf
• File Type:
  [PDF - 1.90 MB ]