thanks for the detailed reply. i actually used a 2d model without columns and just now noticed that the eccentricity give rise to horizontal reactions at the supports (vertical loads applied only).
sound kind of backward [ponder]
as far as i can think the boundary condition should be similar...
Hello from abroad.
I am currently working on a concrete slab with elevation gaps and changing thickness. when using plate elements .i have noticed that changing the offset of the slab (even thou the thin slab is still fully fixed within the thick slab) yields different moment results(by 15%...