# K and Column Leaning Factors



## MOOK (Sep 28, 2009)

In the Seismic Design Manual

In the column design for frame with R=3, page 2-26. To determine Pe2, K factor was used without multiplication of Column Leaning factor while in Column Design for SMF in page 4-51, K factor was multiplied with the Column Leaning factor. Does anybody know the reason??

Thanks


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## OVER 65 (Jul 4, 2011)

MOOK said:


> In the Seismic Design Manual In the column design for frame with R=3, page 2-26. To determine Pe2, K factor was used without multiplication of Column Leaning factor while in Column Design for SMF in page 4-51, K factor was multiplied with the Column Leaning factor. Does anybody know the reason??
> 
> Thanks


Being new to EB (wish I had realised earlier that there is a good forum for SE here) and hoping to add my 2 cents, I am wondering if the difference comes from the R factor. R=3 structures do not need to comply with Seismic design; Specifications would suffice (SDCs A,B,C). SMF being R&gt;3, 2nd Order Analysis kicks in; why leaning factor comes in for story buckling. Does this make sense?


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## OVER 65 (Jul 4, 2011)

OVER 65 said:


> MOOK said:
> 
> 
> > In the Seismic Design Manual In the column design for frame with R=3, page 2-26. To determine Pe2, K factor was used without multiplication of Column Leaning factor while in Column Design for SMF in page 4-51, K factor was multiplied with the Column Leaning factor. Does anybody know the reason??
> ...


Correction: Both have Second Order analysis. I am wondering whether the high R=8, compared to the first case, R=3 justified the use of the leaning factor in the SMF case.


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## ipswitch (Jul 5, 2011)

I imagine you're referring to design example 2.5 and design example 4.9. I have the October 2006 printing and it appears both examples use the leaning column amplifier. Maybe you want to look for an errata?

This damn book is driving me crazy. Where the hell do you find Commentary Section C2.2b and Commentary Figure C-C2.4? I can't find them anywhere!

NEVERMIND:

It's all from "COMMENTARY on the Specification for Structural Steel Buildings"

Derp.


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