Could the Three Gorges Dam be at risk for collapse from an earthquake since it sits on a fault line?

The Three Gorges Dam is a gravity dam, so it would tend towards more earthquake-resistant than most comparable objects.

A gravity dam is a type of structure that doesn’t rely on the strength of the materials to resist the forces of reservoir and earthquakes but rather is built to weigh so much that these forces can’t move it enough to fail.

As such, either the ground itself would need to fail (which it was studied for this purpose) or something needs to come along and break off enough pieces that it fails. So, the greatest likelihood of that dam failing or collapsing would be because humans made a concerted effort to do so.