Re:Ask HN: Are thousands of Bay Area workers going to die in...
by wahern on Saturday May 26, 2018 @12:38AM
(#17160240)
> An 8 or (omg!) 9.0 earthquake. There are few buildings that would survive, some hospitals and data centers that are built to very high standards.
San Francisco already had a dozen or so steel skyscrapers by the time of the 1906 earthquake. They all survived the earthquake well, though some succumbed to fire.
The earthquake damage was inconsiderable. Every
building on both side of Market Street stood against
the earthquake. The modern steel-frame buildings
were unhurt, and that style of structure stands vindicated.
The city has to rise from the ashes of
conflagration, and not from the ruins of an earthquake.
(California State Board of Trade, 1906).
I work in one of those pre-1906 buildings--a 10-story steel skyscraper that was one of the very first on the West coast. Whenever there's a small earthquake the whole building jumps, like a truck hitting a bump in the road. While disconcerting, from everything I've read[2] these buildings are quite safe. They were built to be earthquake resistant (though obviously the science and engineering was nascent back them), but more importantly they were built with riveted steel framing. Riveted connections have proven to be extremely resilient and in combination with other (perhaps accidental) behaviors of the materials and framing techniques they perform remarkably well.
Seismic safety isn't necessarily difficult and certainly isn't anything new. But because labor is expensive (it's why nobody rivets anymore and bolted connections aren't more common) seismic engineering in our era is dominated by high-tech solutions and designs that work with cheaper building methods and cheaper materials. Old tech isn't per se unsafe, and some old tech is better than modern tech, it's just not cost effective.
[2] From literature about the 1906 earthquake and other major earthquakes, various seismic studies (see paper, above), and random stuff like articles discussing the strength of riveted hulls in ship building. Caveat: I'm not an architectural engineer or anything of the sort.
San Francisco already had a dozen or so steel skyscrapers by the time of the 1906 earthquake. They all survived the earthquake well, though some succumbed to fire.
(From https://www.aisc.org/globalassets/aisc/awards/tr-higgins/pas...)I work in one of those pre-1906 buildings--a 10-story steel skyscraper that was one of the very first on the West coast. Whenever there's a small earthquake the whole building jumps, like a truck hitting a bump in the road. While disconcerting, from everything I've read[2] these buildings are quite safe. They were built to be earthquake resistant (though obviously the science and engineering was nascent back them), but more importantly they were built with riveted steel framing. Riveted connections have proven to be extremely resilient and in combination with other (perhaps accidental) behaviors of the materials and framing techniques they perform remarkably well.
Seismic safety isn't necessarily difficult and certainly isn't anything new. But because labor is expensive (it's why nobody rivets anymore and bolted connections aren't more common) seismic engineering in our era is dominated by high-tech solutions and designs that work with cheaper building methods and cheaper materials. Old tech isn't per se unsafe, and some old tech is better than modern tech, it's just not cost effective.
[2] From literature about the 1906 earthquake and other major earthquakes, various seismic studies (see paper, above), and random stuff like articles discussing the strength of riveted hulls in ship building. Caveat: I'm not an architectural engineer or anything of the sort.