Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Pouring sequence for box girder bridge on flexible truss scaffolding

Pouring sequence for box girder bridge on flexible truss scaffolding

Pouring sequence for box girder bridge on flexible truss scaffolding

I would like to thank both Austim & Hariharan  for your prompt reply about the above subject.

RE: Pouring sequence for box girder bridge on flexible truss scaffolding

From a Contractor's perspective, I would look at pouring the bottom flange first, then the webs, and finally the top flange.  This way you not only have the falsework supporting the beam, but the bottom flange is distributing the load.  On a structure constructed last year in this manner, the bottom flange was PT’d to an initial stress level for added support.  The best I recall it was a PB design.

RE: Pouring sequence for box girder bridge on flexible truss scaffolding



Thanks for your Eamil reply. However, can you let me know the span of the bridge and the type of scaffolding for the bridge you were involved with. If you poured in the manner you have described then the "U"section formed by the webs and the bottom flange would have been fairlystiff compared to the supporting flexible scaffolding and some considerable weight of the top flange would have been carried by the bottom falnge. How did the bottom flange and the webs i.e. "U" section carry the stresses due to this weight. Please write me in detail when you find time. Many thanks again.

Bimal 1

RE: Pouring sequence for box girder bridge on flexible truss scaffolding

This cast in place box girder structure was approximately 1100' in length, and the average span length 225'.  The bottom flange averaged 10", and was blistered near the corners for post tensioning ducts.  The falsework system consisted of driven pile, supporting a homemade 'mabey' type structure, supporting a combination of timber and steel stringers, and a plywood platform.  It sounds stiff, but was only stiff enough to cast the bottom flange.
After curing, the flange being supported by the pile system, became an excellent work platform to form and pour the webs, two internal plus the external, and the top flange, which was placed using a traveling form system.  The overhangs were cast using another traveling form system cantilevered from the top flange.
After curing, a considerable amount of post tensioning, both longitudinal and transverse, was completed.  
As best I recall, the top flange was 58’, including the 14’ overhang on each side, the bottom flange 22’, and the webs about 9’.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close