Column/Cap Rebar Development Length

[MoonBridge]

I am verifying the required development length for a cap/column connection point. And I am curious about how I would calculate the reinforcement confinement factor to reduce the development length. My understanding is that the reinforcement of interest would be the length of column reinforcement being developed into the bent cap. This means that the confinement factor would care about the reinforcement within the bent cap potentially confining the longitudinal column bars. Can I consider the cap longitudinal reinforcement to confine the embedded bars? Or would I ignore this factor for this scenario?

Here are some quick sketches to hopefully help better illustrate what I am asking.




I don't imagine the cap reinforcement to be doing any meaningful confinement. So it is my understanding I would then have to use the basic development length. What about in a scenario of a rectangular column as shown below?

Part of my confusion comes from AASHTO showing the confining column reinforcement in Figure C5.10.8.2.1c-1.