Compute Earthwork Materials - Non Vertical

[Ely]

I am working on computing earthwork materials from surfaces off of a corridor I built. The problem I am having is when I compare the two surfaces in a section to calculate the volume it clips the comparison vertically. See attached. 94397 I am looking for a comparison to the extent of the two surfaces. Is there any way this can be achieved? Thanks in advance.

[Opie]

Do you have sample lines at the locations you are missing?

You could also generate a volume surface to compare the volumes between the two surfaces.