Designing a Critical Link to Withstand a Natural Disaster and Allow for Humanitarian Operations

Last summer I had the pleasure of attending an I3P (Institute for Information Infrastructure Protection) meeting in Berkeley, California. I wrote about my travel experiences on this blog.

During my travels back to the San Francisco airport (with some detours on the shuttle since we picked up commuters) I also had the experience of going over the Bay Bridge and to see the replacement bridge under construction, which is scheduled for completion in 2013. At that point, the existing eastern span bridge will be torn down.

Bridges have always fascinated me for their design and as critical links in joining communities and regions. It also helps that my favorite uncle has educated me over the years about bridges, since he worked for decades as a bridge designer in NYC and has received numerous awards for his engineering work.

The New York Times has a very interesting article, "A Bridge Built to Sway When the Earth Shakes," written by Henry Fountain, which states that designing the replacement bridge so that it stays intact in an earthquake has always been the engineers' chief goal. Remember the earthquake of 1906 that destroyed much of San Francisco as well as the earthquake of 1989 that partly severed the Bay Bridge in San Francisco.

According to the article there is a 2 in 3 chance that an earthquake of a magnitude of 6.7 or higher will hit the San Francisco area before 2036 and this new bridge was designed to be able to handle the largest movements of the earth expected to occur in 1,500 years!

What also very much impressed me and this I am sharing with my students in the Humanitarian Logistics and Healthcare course that I am teaching is that the bridge, even after a major earthquake / disaster is expected to be serviceable and the damage reparable. Moreover, according to the article (note the foresight in terms of emergency preparedness and response):

Emergency vehicles and personnel, at the least, should be able to use the new bridge within hours of a major earthquake, after crews inspect the structure and make temporary fixes.... Given that the Bay Area's two major airports would be expected to be out of service after such a disaster, this bridge and the Benicia-Martinez Bridge, another seismically secure span about 20 miles to the northeast, would be "lifeline" structures to bring assistance to the stricken region from an Air Force base inland.

We have developed metrics to identify critical nodes and links in transportation and other infrastructure networks and also how to assess performance of critical needs supply chains subject to disruptions, as one would expect to occur in a natural disaster, for example. The latter work is reported in a paper, "A Bi-Criteria Indicator to Assess Supply Chain Network Performance for Critical Needs Under Capacity and Demand Disruptions ," Qiang Qiang and Anna Nagurney, to appear in Transportation Research A: Special Issue on Network Vulnerability in Large-Scale Transport Networks.

It is very good to see that California understands the importance of the replacement bridge for the San Francisco Bay.

And if you are wondering where the steel for this bridge (it's actually the eastern span) is coming from -- it is coming from China and is being transported 6,500 miles to Oakland!

According to an article that appeared last summer in The New York Times: The assembly work in California, and the pouring of the concrete road surface, will be done by Americans. But construction of the bridge decks and the materials that went into them are a Made in China affair. California officials say the state saved hundreds of millions of dollars by turning to China.

This is really "the ultimate in outsourcing."