SCBF - Balancing tension and compression

[vato]

Can you really have diagonal bracing in one direction per fig C-I-13.1 Seismic design manual?
If so, is it done very often?
It sounds like if the bracing members were strong enough in compression, then it is allowed per the code.
It also seems like the connection and brace would be horribly big, but within code if designed for the forces.
I sure appreciate any clarification. It feels like it's allowed, but perhaps not the best approach if you can have opposing braces.

 

[cntw1953]

Tension only brace, I guess it is, is used in most of low rise buildings with low or moderate lateral load. Quite often, you will see X rather than a single brace, however, only the one subjects to tension is considered active when loaded.

 

[Gumpmaster]

Yes you can, but read 13.2c "Braces shall be deployed in alternate directions such that, for either direction of force parallel to the bracing, at least 30 percent, but no more than 70 percent of the total horizontal force along that line is resisted by braces in tension..."

An individual braced bay can have the braces all pointing in one direction, but the next bay in the line of bracing would need them oriented the other direction.

An exception to this is if you design the braces for the amplified load.

 

[sandman21]

No tension only braces in a SCBF

 

[cntw1953]

Yeap, my mistake.

 

[BAretired]

Sometimes an 'X' brace interferes with a door or window. In that case, a single brace may be used, but it should be designed as a compression strut.

BA