cae_1_rfh,
Your initial set up was correct. You cannot use dload to combine gravity load with spc or spcd.
When you give enforced displacement within the spc itself and refer grav in the LOAD card, you are in fact combining enforced displacement and spc. This is what you have done, these results if they do not agree with your experiment/calculation etc it is perhaps due to a different discrepancy while modelling.
When you need to use nload it should be as in this attached deck
you will be creating an nload 1 for grav (you can give a time function here if necessary, using tabled1)
another nload 1 for spcd (if you are defining enforced displacement via spcd)
combine these nload 1 cards in an nload and refer this nload in the nload filed of your nlgeom loadstep
