Answer:
The change of the vertical position or an eccentricity has an effect on the bending moment My only if there are other forces acting on the model that are included in this moment, such as the axial force in the following example.
A slab, supported as a single-span beam, is only loaded vertically on the left in the image. The bending moments of the result members positioned above and below the slab do not differ.
On the right, the slab is additionally loaded by an axial force. Therefore, the result members obtain additional negative or positive moments. The eccentricity acts as a lever arm.
