Seismic System designation Question

[Grizzman]

I am designing a free standing mezzanine with moment connections at the beam to column connections. I plan on leaving the column pinned to the footing to reduce the footing size.
So my question is this: What seismic sytem would this be considered according to the IBC? My initial thought was an inverted pendulum system with ordinary steel moment frames. This yields a very low R value though, so I'm not sure this is correct. Would it still be appropriate to consider it a moment resisting frame and use a higher R value?
I guess the real question is what makes a moment system an inverted pendulum system?(versus a moment resisting frame system)
I've been looking for an explanation, but as yet, have been unsuccessful.
Thanks for the help.

 

[SperlingPE]

This is a moment frame.
Look in the definitions for pendulum system in the IBC 2000 in section 1613

 

[Grizzman]

Thanks.
Didn't think to look at those definitions.

 

[samdamon]

Grizzman- Don't forget to consider using R=3. Depending on where your project is, could save you detailing and engineering time. Regards.

 

[AlohaBob]

When I read the definition I see a single column supporting a large mass at the top.

For a frame, there would be multiple columns or lateral elements carrying vertical and lateral loads.

The higher R value prescribes for less paths to provide stability ( there's only one column) should failure occur in that single element.

I agree with SperlingPE. You describe multiple supports. So you have a frame.