Special concrete moment frame

[ARKeng]

I'm designing a concrete building in SDC D (IBC 2003). We wanted to use concrete shearwalls alone, but the SDC and height requirements are forcing us to use a dual system of shearwalls and special moment frames.

Does anyone know if it's possible to create frames that meet the "special moment frame" criteria with only using the 2-way slab instead of beams? We have a 8.5" thick PT slabs and a ton of columns to spread the load to, so it would be attractive, if possible, to not have to add beams. However, based on my reading of the ACI tie/reinforcing requirements for special moment frames, I don't see that it would be possible without beams. My boss is convinced he's seen it done in other buildings but I'm wondering if the requirements may have changed.

Can anyone help?

 

[prsconsultant]

You can not create an SMRF using 2-way slab system. I had a very similar situation and had asked the same question to ACI a while back and below is their explantion:

As stated in Paulay and Priestly, Seismic Design of Reinforced Concrete and Masonry Buildings, "flat slab systems supported by columns is considered to be unsuitable on its own to provide satisfactory performance under seismic actions because of excessive lateral displacements and the difficulty to providing the adequate and dependable shear transfer between columns and slabs, necessary to sustain lateral forces, in addition to gravity loads."