×
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

Repair Cracked Timbers

Repair Cracked Timbers

Repair Cracked Timbers

(OP)
Hi

I am working on a project involving heavy timber trusses which have cracked timbers due to drying. The truss connections are steel plates with bolts and 4" diameter shear plates. The cracks run directly through the bolt lines in many of the trusses.

I am considering many different repair options including steel dowels set with epoxy, structural timber screws, external steel rods for tension members.

Does anyone have any experience with this type of repair that could offer some suggestions?

Thanks
 

RE: Repair Cracked Timbers

I repaired similiar trusses at an old hanger building - Air Force structure that had been built in the 1940's as a bomber factory during WW2.

The trusses were glue-laminated top chord and heavy timber diagonals and bottom chord if I remember correctly.  The top chord was a bowed chord (bent gluelam).  The bottom chord was dried out and cracked in many places.  The connections were via split ring shear connectors with through bolts.

We added additional side plates that were connected to the bottom chord with through bolts and then welded on horizontal, continuous tubes to serve as "new" bottom chord members.  The tubes were spaced off of the side plates to allow the through bolts to be installed.

This effectively prevented bottom chord tension failure only - we had determined that the bottom chord to diagonal connections were OK.  

Trusses spanned about 150 feet if I remember right.

See the attached section/sketch.

 

RE: Repair Cracked Timbers

I would consider clamping the members across the splits.  This should allow the shear plates to continue carrying the load.

Is corrosion in the connections involved?  This could be at least part of the cause of the splitting and may require replacement of bolts.

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