My immediate thought was: Each section should be made so the 'man holes' would fit, no matter how they are arranged. But I think you have another plan in mind.
No matter what, the idea of '3D corridor sections' is great and could be used for a lot of purposes.
I have an 'elevated' game board, under which one could arrange some sub-terranean tunnels/corridors in multiple levels, so I might 'steal' the concept for future projects.
