BRBF vs SCBF

[RobertHale]

The Back-story

I am a structural working in Georgia. Up to now I have done jobs mainly in the southeast and using "Steel Systems not Specifically Detailed for Seismic Resistance" has served in all cases. The only experience I have with 341 was a result of studying for my licensing exam. Now my boss has assigned me to work on drink packaging facility expansion in California. I am working with another consulting engineer here in Georgia that is licensed in CA.

The Question

At first we explored using OCBF but the diaphragm loads that resulted indicated we would have needed to place a frame in the middle of the building. By using SCBF, we got the diaphragm loads down so that it works for strength spanning the whole building. Since we were in SD right now I did not look at the deflection yet, but I figure this will be an issue and it may well mean another brace is required to reduce the span, but that is a topic for another day. On my way into the office this morning, I realized that another option for the bracing would be to use a BRBF, but I have absolutely no experience with them. In turning it over in my mind, it seems like I could use this system to reduce the load and increase the length of my braces. Currently I am expecting to provide an intermediate beam in the braces to get the length down to something manageable for a bare tube. The two main questions I have are: 1) what is the typical cost differential between a BRBF and a SCBF, and 2) Am I correct in assuming I can get a longer brace length.

Thanks in advance for any help you can provide me and I am sorry if I rambled a little bit.

 

[JoshPlumSE]

I haven't much experience with BRBF's either. But, know that they do significantly increase the drift of the structure. So, if you're already having deflection / drift issues, then they might not be a viable option for you.

I imagine that if you would contact one of the BRBF firms directly then they should be able to help you. In my experience they are not like used car salesmen pushing a high pressure sale. Rather they are strong advocates for their product. If they can't help you too much with this job then they're still hoping that you feel comfortable enough that you'll use it on another job down the line.