I'm looking at a podium slab with a 6" step in the top of slab (constant soffit across the step) for a topping slab in a courtyard area. We added a 75psf area DL in the 6" recessed area to account for the topping slab weight and get the following bottom stress plan (distributed tendons running L-R):
For a number of reasons, the step in the slab needed to move to right by a few feet. I adjusted the area DL to match the new step location. So, the loading is essentially the same in the area with the thicker structural slab being adjusted to extend further into the courtyard. This produced a large jump in the bottom stresses:
Is there a reason for this? The loading isn't any different aside from some of the DL shifting from the "other dead loading" to self weight, and with the CS inter cross section slope limit set to 0.25 you have the same design strip section at the new step location as you did when the step was located further to the left.