Reduced Beam section Special moment steel frames

[casasf]

In the protected zone of an RBS special moment connection, we are not allowed to attach to the flanges. What about the web? Can we attach to the web within the protected zone w/bolted steel angles to pick up a framing members? I checked with FEMA books and AISC seismic manual, there was no mention of web. All the reference material has to do with flanges.

Can some one shed some light?

Thanks in advance.

 

[wannabeSE]

I have never seen any reference that suggests the beams web is not included in the protected zones. There is only one exception I know for RBS webs and that is for the erection bolts.

See AISC 358-10 general protected zone requirements in section 2.6
"Bolt holes in beam webs, when detailed in accordance with the individual connection provisions of this Standard, shall be permitted."

For RBS, see section 5.6.(2)(a)
"Bolt holes in the beam web for the purpose of erection are permitted."

The extents of an RBS protected zone is defined in AISC 358-10 section 5.3.1.(8):
"The protected zone shall consist of the portion of beam between the face of the column and the end of the reduced beam section cut farthest from the face of the column"

 

[KootK]

I'd err on the safe side with this. Although the web will see less strain than the flanges, every fiber of the section needs to yield, strain harden, and go through several reversals before the plastic hung has done its job.

The greatest trick that bond stress ever pulled was convincing the world it didn't exist.