×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Deteriorated Web Analysis
2

Deteriorated Web Analysis

Deteriorated Web Analysis

(OP)
We are performing the load rating of a bridge that exhibits significant corrosion of the steel webs near the abutments.  The webs have holes near the bottom flanges, the largest of which is 2" high, 16" long.  I am having trouble calculating the shear capacity.  I am uncomfortable using the reduced web depth for calculating a conventional shear capacity (reduced d x tw x Fy), but I also believe I should not give a capacity of zero either.  Is there any information out there for analyzing such a case?

Thanks for any information.

RE: Deteriorated Web Analysis

Just a guess - what about following the shear capacity rationale of a castellated beam?

RE: Deteriorated Web Analysis

With the holes near the bottom flanges, is the girder bearing on the bottom flange or is it integral with the abutment?

If there is a hole near the bottom flange, then as the beam approaches the support abutment you transition into a "T" beam with the stem in tension.  Assuming the web is adequately supported at the very end - you can determine a moment and shear capacity of the "T", ignoring the bottom flange altogether as it is not effective in resisting any stress at all.

RE: Deteriorated Web Analysis

(OP)
Thanks for the responses.

The girder does bear on the bottom flange, but it doesn't at the very end due to the hole.  I agree with your method for moment capacity, but what about shear?

RE: Deteriorated Web Analysis

Perhaps you can utilize AISC's method for checking beams with "web openings".

Now with the deteriorated opening very close to the bottom flange, you will probably violate some of the min. distance requirements between opening and flange.  But I do think it checks the shear across the sections with the opening either unreinforced or reinforced.

Another option would be to simply reinforce the deteriorated opening by adding a web cover plate and perhaps some horizontal stiffner plates that run from the end of the beam out past the opening.  This would create a form of wide flange beam that could be checked in a traditional fashion.

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!


Resources