Close Column Offset on Transfer Slab 1

[efFeb]

Hi,
I'm designing a transfer slab that has a number of columns transferring near supports below. What I am most concerned/unsure about is shear along the plane shown in my attached sketch. What I would like to check here is 1. Interface shear between the column below and transferring column above and 2. Local one-way shear between the two columns at the location shown in blue.
I'd love your input, if you've come across similar situations in the past, on these and any other checks that might need to be considered. I'd be especially interested in hearing your thoughts on what width would be reasonable to consider for the local one-way check, and on whether adding horizontal reinforcing for an interface shear condition is necessary if I have satisfied one-way flexural shear at this local region.

Thanks so much for your time!

 

[efFeb]

Thanks everyone for your answers. I was thinking about the strut and tie model for this, and am left wondering, why do I need the rest of the beam? If this were deep enough, is this similar to the model I might use for a corbel? And if this beam is not deep enough for a single direct diagonal compression strut, is this an issue?
I'm sorry if these questions are getting us in the wrong direction; I have used strut and tie models for deep members like wall beams and footings before, but not for something shallower like this. I am having a difficult time coming up with a strut and tie model that makes sense to me.
Thank you so much again for your time.

 

[r13]

I think you already realize that you'll need a thick section to 1) develop truss action to transfer the upper column load to the column below by stress cone overlapping; 2) overcome the shear force, and 3) allow the development of the upper column reinforcement. The thick section can be a slab with uniform thickness, or a beam with shear reinforcement, the end result is the same, but the beam option potentially can save some concrete by using thinner slab (like T beam), and reduce the dead weight. If you are still worried about two way shear on the lower column, then you can provide transvers beams on each side of the lower column to take care of shear on the other direction.