This is of course based on pure ignorance.  The bigger a project the more likely it will have the most state-of-the-art earthquake safeguards, which are tremendous.  Earthquakes are simply not a concern for a project like this.  If a quake occurs and the tracks spread there will be immediate breaks put on all running trains.  After the quake you fix the tracks.  It's not really a huge deal.

Tall buildings, for the record, are built with counter-weighting and shock absorption that makes them far safer in an earthquake than your new McMansion.