|New eastern span in front of the old eastern span|
(Steve Jurvetson, Menlo Park, http://commons.wikimedia.org/wiki/File%3ANew_and_Old_Bay_Bridge_(8859593785).jpg)
Nonetheless, this is an earthquake story coming and going; having been started because of an earthquake in the previous millennium and resulting in new structure built to withstand the type of quake that is expected every one and a half millennia.
I’ll give a bit of background here and then will link to a very interesting and informative story that appeared in the San Francisco Chronicle on Sunday, about the preparations for what was to have been Tuesday’s grand opening of the new Bay Bridge (although it opened ahead of schedule, Monday night).
|Bay Bridge western span|
© Túrelio (via Wikimedia-Commons)
|Bay Bridge eastern span (original)|
(C.E. Meyer, U.S. Geological Survey, public domain)
Despite cost overruns, continued design debates, and ironically, the discovery earlier this year that many of the bolts and seismic safety rods in the bridge were defective, the technologically cutting-edge, self-anchored single tower suspension span started carrying traffic today.
For some pretty incredible information about its seismic design (basically, just about every piece is only loosely connected to every other piece!), check out this article that the San Francisco Chronicle ran on Sunday. I encourage you to flip through the photo gallery; some of those pictures give you a great contrast between the old and new bridges. One of them is actually a short video, which is also worth watching. There is a lot of extra information in a diagram that shouldn't be missed (this graphic on the Chronicle site currently has a technical glitch so that it can't be enlarged and is unreadable; I've notified them and have temporarily posted an enlargeable version here).
Next, they start dismantling the old bridge. That should take them about 3 years. Unless, of course, the next big quake hits before they finish; that could shorten the job!
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