STS Stack Design -- Anchor Rod Specifics

[henerythe8th]

I am not responsible for the design of the stack.
I got involved due to an 'odd' installation methodology.
Since then a lot of discussion has been had about several characteristics of the stack design, anchor rods, etc.
I have researched ASME STS-1, SMACNA Guide for Steel Stack Construction, Troitsky's Tubular Steel Structures, these fora/forums, the internet, numerous other engineers, etc.

1) When the stack is designed with a pair of flanges and stiffeners in between (external chairs) is there an expectation that the fasteners will be installed only on the top flange of the pair?
2) Theoretically, the anchor rods are in tension from the head embedded in the concrete to the point at which the nuts are placed on the top of a flange. Is the additional distance between the pair of flanges important to keep in tension? (eg. 14" embed depth plus grout space plus distance from bottom of base flange to top of upper flange vs. the situation where nuts could be placed at the top of the base flange)
3)What method should be used to tighten the anchor rod nuts?

I have my ideas.
I hope to get opinions, yet I endeavor to get sources for information bound in design guides, specifications, or codes.

 

[KootK]

1) yes. This is to allow a "stretch" length in the bolts so that they can be prestressed.

2) yes. Same as #1. Anchor prestressing can improve fatigue resistance.

3) Impact wrench with measured elongation.

There is a PIP document on this that is useful.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[henerythe8th]

Howdy KootK!
Thanks for the response.
Do you have information that relates your answers to code, specifications, etc.?

What is a PIP document?

Thanks!

 

[KootK]

Process industry practices. That's all that I know of for stuff in print.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.