Investigation of flange failures in falsework cap and sill beams : recommendations for the design of beams and posts in bridge falsework.

Details

• Alternative Title:
  Recommendations for the design of beams and posts in bridge falsework.
• Creators:
  Carden, Lyle P. ; Itani, Ahmad M. ; Pekcan, Gokhan
• Corporate Creators:
  University of Nevada. Dept. of Civil & Environmental Engineering
• Subject/TRT Terms:
  Bridge Failures Bridges California Design And Construction Temporary Structures (Building)
• Publication/ Report Number:
  CA06-0629
• Resource Type:
  Tech Report
• Geographical Coverage:
  California
• Corporate Publisher:
  California. Dept. of Transportation. Division of Research and Innovation
• Abstract:
  Recent field observations in bridge falsework identified potential deficiencies in the design of falsework resulting in
  
  localized bending in sill and cap beam flanges and lateral buckling in other beams. Possible limits states associated with
  
  the bearing of timber and steel posts on cap and sill beams are investigated in this report. The critical limit states are
  
  related to flange bending, post crushing or yielding, web yielding, web crippling, lateral web buckling and corbel
  
  crushing. Different methods are investigated for predicting the capacity of the flange. The first assumes a uniform
  
  stress distribution resulting in bending of the flange. This is adequate for timber posts, but not as accurate at the second
  
  more elaborate method which accounts for an interaction between flange bending and post compression strength, found
  
  to be effective for timber posts. The third method uses an effective bearing area of the post, which is more effective with
  
  steel posts. For beams with relatively thick webs, such as those typically used in bridge falsework, the web was found to
  
  have a greater capacity than the flange and posts. The critical web limit state was web yielding (referred to as web
  
  crippling in the Caltrans Falsework manual) with variations of existing equations found to be appropriate for predicting
  
  the capacity. Web crippling (as defined by ASCE) is found to generally not govern the design, particularly when two sill
  
  beams are stacked on top of each other. Blocking may be used to increase the flange bending and web yielding
  
  capacity, although lateral bracing or stiffeners are recommended to increase lateral buckling capacity. Design equations
  
  are presented in allowable stress design format for the consideration of the critical limit states in a falsework bent.
  
  These are compared to current Caltrans design practice and other relevant specifications. Two design examples are
  
  also provided to demonstrate the application of these equations, one using timber posts and a second using steel posts.
  
  
• Format:
  PDF
• Funding:
  DRI Research Task No. 0629;Contract No. 59A0445
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:f425488ec5c3120f8dee436102b5dd01390b8eadea0220dd139265273cfd0236cdea7e40906e642cb97360e5561103a4d5f5ae5124e5084bb662d3683428d513
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27707/dot_27707_DS1.pdf
• File Type:
  [PDF - 3.14 MB ]