I have topography that was modelled incorrectly by our As-Built company so that it does not show the topography cut to accommodate an existing slab. In order to properly calculate the cut/fill using the graded region command, I have used a model in place void extrusion to cut the existing toposolid where the existing building slab is. The problem is that when I use graded region, the new toposolid does not include that void extrusion and simply reverts back to the original toposolid. How can I fix this? See pictures below for reference, I have circled the area where the existing cut I've modelled is and where it should be in the new toposolid.
