Warehouse (Truss Bracing)

[slickdeals]

All:

I have a warehouse type building where lateral loads are resisted by a portal truss frame (parallel to short face) and tension-only X bracing (parallel to long face). The roof is supported by Z purlins bearing on the top chord of the truss.

My question is regarding the bracing of the top and bottom chord of the truss. I have two options.
OPTION 1
In the braced bay, I intend to provide a top and bottom chord X-brace. I use bridging members to brace the chords (which are tied to the lateral system).

OPTION 2
The other option would be to only provide a top-chord bracing on the braced bay and provide X bridging on the braced bay. The other bridging would remain the same.

What is missing in the attached sketch is that my X brace in elevation should extend to the top chord in Option 2 and I should have an additional brace between top & bottom chord in Option 1.

Is there a preferred way to do it? Or any other way that I may not be thinking?

It’s no trick to get the answers when you have all the data. The trick is to get the answers when you only have half the data and half that is wrong and you don’t know which half - LORD KELVIN

 

[DST148]

Option #3 - Option #1 + x-bracing between top and bottom chords of the braced bays along bridging lines, keep the main X-Bracing in the longitudinal direction the way it is shown in the sketch and add bracing above longitudinal main bracing in the braced bent only. This would make it truly three-dimensional-truss. Moreover, the portal truss frame would be laterally braced both at the top and the bottom chord level.