Not sure why your comment is being downvoted. It is obvious that the shell theorem only applies to Earth and not the steel ring (it's not the ring that is withi

Not sure why your comment is being downvoted. It is obvious that the shell theorem only applies to Earth and not the steel ring (it's not the ring that is within a shell) and only to the plane of Earth that is in the plane of the ring. While the single plane (crossection) of Earth would not see gravitational gradient from the ring it is only because each part of that crossection of Earth is being attracted to all parts of the ring in a way that all forces cancel each other. For the ring itself, each part of the ring is being attracted by the Earth that is beneath it. There is no magic, the Earth is not a shell around that part of the ring and and full force of attraction is felt. The compressive force on the steel would just squash it immediately. No known material would be strong enough to support itself in this configuration. Think about an arch that is 5 feet high standing on the Earth. Now start making the span wider while keeping its height. The arch gets shallower and shallower until the radius of the arch is the same as radius of Earth. The wider the span and the shallower the arch the stronger the material needed and the less force it can carry.