Seattle Alaskan Way Viaduct Earthquake Destruction Simulation

Only 20 more days until the 10th anniversary of the Nisqually Earthquake (Seattle Earthquake for all you non-native Washington folks).  It was a magnitude 6.8 event that I called the "snooze alarm" earthquake.  Instead of being a wake-up call, people hit the snooze button and dozed off back to their unprepared ways of living.

 

The only item that has dominated the news in seismic safety since then has been the Alaskan Way Viaduct.  A 70's vintage elevated roadway that follows the Puget Sound shoreline right through the heart of the downtown Seattle area.  What ensued after the 2001 earthquake was a debate about what to do with the structure.  Options included:

• Tear it down, no replacement--open space
• Tear it down, replace with a similar elevated structure
• Tear it down, put in a surface roadway
• Build a deep bore tunnel, tear it down after it is completed
• Wait for another earthquake to take it down, wring our hands and point fingers on why it wasn't replaced

The two options still being pursued include the deep bore tunnel.  A contract was just let in late 2010 for the construction.  Yet another "Stop the Tunnel" vote is being proposed with a signature gathering effort supposedly to provide a "vote of the people" on what to do.  I know democracy is the best political system in the world, but sometimes...I begin to wonder...  Maybe we are the best, but certainly not the most efficient!

 

The other option still available is the last one.  It is the de facto solution that will happen at some date no matter what people do.  The recurrence rate for a deep earthquake like that of Nisqually is an average 30 years.  We have now used a third of the time that "maybe" mother nature has given us to take some action on what has to be one of the most fragile roadways in the nation.  It carries around 90,000 vehicles a day.

 

Check out the video simulation of what might happen when there is another earthquake and the Alaskan Way Viaduct is still standing.  This is one of the few items of information that provides a little bit of documentation about the seawall that is also at risk.  Portions of it are 100 years old and made of old wooden timbers.  Its failure in an earthquake will bring about significant risks to even the modern buildings built along the waterfront.