Baseplate to nut contact
2

Question

Baseplate to nut contact

WWTEng (Structural)

(OP)

5 Aug 24 00:57

Hello,

I have a situation where a steel column (exterior, W12) is leaning due to the foundation heaving about 3/4". The foundation is at least 30 years old, so is the steel. I guess the issue was recently notice by the facilities.

In order to correct the issue "temporarily", the site crew went ahead and placed some shims under the baseplate (18"x18") on one side. Its their attempt to level the column for now.

But the nuts above the base plate are no loner in full contact with the baseplate due to the BP now leaning.

Where can I find some literature on the contact surface issue?

Thank you.

MRob909 (Structural) · Answer 1 · 2024-08-05 12:04:24

A picture might help - but what I'm imagining is that you do not have a square contact of the nut face to the baseplate face?

Depending on what loads are anticipated in the column and the duration of the column in this temporary state are likely to be factors in your decision to intervene with a remedial solution.

Are you able to introduce a wedge washer plate? or jack and shim the column straight?

WWTEng (Structural) · Answer 2 · 2024-08-05 17:11:22

Picture is attached, although you can't tell that the foundation has tilted.

https://files.engineering.com/getfile.aspx?folder=eea8bfd4-b4f9-4c22-825e-4

Heaviside1925 (Mechanical) · Answer 3 · 2024-08-05 21:43:33

If you are trying to find justification for the nuts not being in full contact, I don't think you will. To view this system as an anchored column, you have to have full contact to be able to determine proper bolt stretch and hold down. I think MRob909 suggestion of a wedge plate washer is as good as you are going to get.

Tomfh (Structural) · Answer 4 · 2024-08-05 23:29:40

A fine tuning hammer will straighten up those bolts.

desertfox (Mechanical) · Answer 5 · 2024-08-06 08:00:19

Hi WWTEng

You could try tapered washers for a temporary situation.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

Come Join Us!

Posting Guidelines

Baseplate to nut contact
2