×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Haunch and Beam Seat Elevations for Prestressed Bulb T

Haunch and Beam Seat Elevations for Prestressed Bulb T

Haunch and Beam Seat Elevations for Prestressed Bulb T

(OP)
Hi all. I am trying to calculate haunch and beam seat elevations for a 2 span bridge composed of prestressed bulb T beams. The roadway is on a crest curve.

Now for a straight gradient, it should be calculated as follows, correct?

Net camber = the upward camber due to prestress force - deflection due to self weight of beam - deflection due to deck/haunch/SIP forms.

Minimum haunch at supports = Net camber + minimum haunch/tolerance required by DOT (in my case this minimum is 3").

And therefore:

my beam seat elevations = Elevation of finished grade - deck depth - beam depth - min. haunch at supports calculated above - bearing/pad height.

Now I am a little confused in regards to a crest curve. How should I calculate the minimum haunch in this case? Using the method for a straight gradient above, I was getting quite a large haunch of over 7" at midspan, so I know I need to adjust for the vertical curve.

Should I calculate the difference between the horizontal reference line drawn from beam end to beam end and the max. height of the vertical curve along the beam = "vertical ordinate"

and then minimum haunch at supports = net camber + 3" (min. required) - vertical ordinate

or do I have this wrong? Also, what about deflection due to superimposed dead load? Should this also be subtracted to get my net camber? Some help on this would be appreciated. Thank you!

RE: Haunch and Beam Seat Elevations for Prestressed Bulb T

(OP)
Thank you both for the help!

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


Resources

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