It's an elevated track so it really could be designed to deal with that kind of break. Water, Oil, and Gas pipelines for example have long dealt with those issues without breaking when designed correctly.
Now doing this without bending the long pipe is going to be harder, but you really could design this thing so riders don't notice a magnitude 9 earthquake.
PS: In the end you get into cost benefit designing it to survive an aircraft impact is probably not worth it let alone a nuke, but predictable earthquakes are not that hard.
http://www.snopes.com/photos/accident/graphics/gasline2.jpg