Embedded Plate at Concrete CIP Column

[Paisace]

I need to connect a steel beam (W-shape) to a concrete columns (30"X30"). I was planning to use an embedded plate with welded headed studs. I checked the concrete capacity following appendix D of ACI 318-08 for a two edge condition (edges parallel to the shear force). The edge breakout mode controls and basically does not meet the required strength. I was wondering if i could use the column rebar or add more to help resist the forces at the parallel edges. I was thinking of adding more stirrups around the main column reinforcing just at the embedded plate location. my theory is that the vertical bars in the column will try to resist the edge forces so the stirrups will be then engage in tension. I would appreciate any suggestions.