How would you classify this frame?

[hawkaz]

I am struggling to classify this steel frame-
Seismic Design Category D

It is existing and I am trying to justify that it works


Thanks

 

[msquared48]

Looks like a braced frame to me, but, if it is a two story frame, I would watch the soft story scenario.

Mike McCann
MMC Engineering

 

[JAE]

With bending in the columns providing the primary resisting system - I'd almost call it a moment frame.

 

[wannabeSE]

If seismic design coefficients from ASCE 7 are needed, you might consider using "Steel System Not Specifically Detailed for Seismic Resistance." R = 3, [Ω] =3, Cd = 3

 

[JLNJ]

Be careful - if your compression chevron buckles and you get a hinge in the middle of W you don't have much left for stability.

 

[tolchijb]

wannabeEIT, you cannot use "Steel system not specifically detailed for seismic resistance" in SDC D.

 

[hawkaz]

Thanks for everyones help.

I was leaning toward moment frame. I may go with the R of 3 to be on the conservative side.

I agree about the hinge also

I appreciate the input

 

[wannabeSE]

tolchijb,
The frame is existing. I may be wrong, but I would be suprised if it meets the detailing requirements for any system in AISC 341-05. I would use the factors for Steel System Not Specifically Detailed for Seismic Resistance because they are somewhat consevative compared to other steel frame systems.