Effective Length Factor for a Roof Column without Beam

[Nick6781]

I have a situation where the roof column has no beam frames into it. The tip of the column is connected to diagonal bracing though. What k factor should I use? I'm thinking of using the horizontal stiffness of the bracing as a beam and calculating G. Does this make sense?

 

[Greenalleycat]

I'm a bit confused
I'm assuming this is an elevation of a 'braced frame' and that the joints are all pins?

If you've got axial loads on the columns then I would assume k = 1.0 for buckling left-right, relying on restraint from the x-brace
Obviously, we have no dimensions etc so I'll leave it to you to consider the reality of that

In-out of the page we have no info but that brace will obviously not do anything to support it

 

[DaveAtkins]

If you do a P-delta analysis, K is always equal to 1.

DaveAtkins

 

[TRAK.Structural]

Agree with Greenalleycat here.

If you have sufficient strength/stiffness of the braces and all pinned connections I think k = 1.0 for left/right buckling is reasonable. Need to evaluate buckling in/out of the page though if conditions differ in that direction.

Is there more to this structure? Other bays of framing, roof deck, etc?

 

[BFstr]

Ignor the bracing and assume a completely free top end column