×
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

Benefit to welding washer to baseplate?

Benefit to welding washer to baseplate?

Benefit to welding washer to baseplate?

(OP)
When anchoring a column baseplate to existing concrete, is there any benefit to welding the edges of a square washer to the baseplate?

Specifics:
1-1/2"Ø Anchor through 2-5/16"Ø holes in 1" baseplate
Square washer is 1/2"x3.5"x3.5" with a 1-9/16"Ø hole

While reviewing the drawing I haven't thought of a benefit to welding the washer to the baseplate.

RE: Benefit to welding washer to baseplate?

Shear transfer.

RE: Benefit to welding washer to baseplate?

it is to transfer shear forces to the anchors. The holes in the base plate are huge, so the bolts must bear against the standard holes in the washer, and thus the washer need to be welded to grab the force from the base plate.

RE: Benefit to welding washer to baseplate?

(OP)
Makes sense, thank you

RE: Benefit to welding washer to baseplate?

looks like in the worst case that square plate will cover the 2-5/16" hole by less than 3/16"

RE: Benefit to welding washer to baseplate?

Yes, the square plate needs to be larger - though it has the smallest reasonable hole.
What size fillet weld for the 1/2 thick plate to the baseplate? What is the shear force expected, a 1/2 inch fillet seems much too heavy to be economical.

RE: Benefit to welding washer to baseplate?

Agree with @Tmoose: the plate washer ought to be more like 4.5" square for this application.
Dave

Thaidavid

RE: Benefit to welding washer to baseplate?

The 2-5/16" hole with a 1/2" x 3-1/2" washer for a 1-1/2" anchor rod is the same as what is listed in AISC's Steel Construction Manual, 14th edition, Table 14-2.

RE: Benefit to welding washer to baseplate?

What's the reason for having the larger holes in the first place? Why not use a 1-9/16"Ø hole in the baseplate itself and skip the washer? I'm guessing for easier field setting of the anchors...

RE: Benefit to welding washer to baseplate?

Quote (bearjew)

What's the reason for having the larger holes in the first place? Why not use a 1-9/16"Ø hole in the baseplate itself and skip the washer? I'm guessing for easier field setting of the anchors...

On a small structure or when using post-installed anchors this would entirely be possible. However, on larger projects (multi-story buildings, etc.) the anchors are cast-in and neither the anchor bolt tolerances nor the structural steel tolerances will allow for standard bolt hole tolerances or even oversized bolt hole tolerances. Often you'll need tolerances beyond the oversized bolt hole for your anchor bolts to fit in the base plate.

Plus, it's almost always cheaper to weld washers than to fight with slightly misplaced anchor bolts or re-fabricate steel.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
www.americanconcrete.com

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