Modeling/Art non-related to Amnesia / SOMA

[Rapture]

You can delete faces at the places you want the loop cut top stop making cuts like the way it does, the spherical type.

So if you had a rectangle split into 10 pieces, and you only wanted to do a loop cut along the 4th-6 pieces. You would delete the 3rd and 7th face so only the 4th-6 faces are affected by the loop cut, not all 10 pieces.

Edit: What is that extra plane/slanted surface on the center support block? (Along the green Axis arrow)