AISC Appx 6...Column Bracing

[joengineering]

I have a column that is approximately 40' unbraced but I have wind girts (bent plates) that are attached to the column every 6' on center. I was wondering if these bent plates offer enough strength and stiffness to provide buckling bracing to the column. I have used AISC appendix 6..the Pu on the column is about 300K so it results that I need 1.2K (.004*Pu) of axial compression from the bent plates. These bent plates span 25' and can take the 1.2K in compression no problem. Am I doing this correctly?

JO

 

[hokie66]

Girts are typically used to brace the columns which support them. But in addition to the vertical load on the column, you would have bending, and it can be in either direction. So both flanges of the column need bracing, and this is usually done by diagonal "fly braces".

 

[joengineering]

Yea I got the fly braces. I am glad to know the column is well braced by these girts.

JO

 

[hokie66]

I didn't say that "the column is well braced". That is for you to determine. I simply stated that girts are typically used to brace columns. However, columns braced by girts do not typically have 300 kips of vertical load. Where does all this load come from?

 

[joengineering]

Concrete roof and long spans. Pu= 1.2D + 1.6L