Posted on 04/18/2018 8:40:20 AM PDT by NRx
...
Clustered around the 1,070-foot tower are a collection of high rises built on the soft soil and sand on the edge of the bay. They represent a bold symbol of a new San Francisco, but also a potential danger for a city that sits precariously on unstable, earthquake-prone ground.
San Francisco lives with the certainty that the Big One will come. But the city is also putting up taller and taller buildings clustered closer and closer together because of the state’s severe housing shortage. Now those competing pressures have prompted an anxious rethinking of building regulations. Experts are sending this message: The building code does not protect cities from earthquakes nearly as much as you might think...
California has strict building requirements to protect schools and hospitals from a major earthquake. But not skyscrapers. A five-story building has the same strength requirements as a 50-story building.
Yet skyscrapers cast a much broader shadow of risk across a city and their collapse or impairment could cause a cascade of consequences.
How safe are San Francisco’s skyscrapers? Even the engineers who design them can’t provide exact answers. Earthquakes are too unpredictable. And too few major cities have been tested by major temblors.
“The profession does the best job we can to model and predict, but there are a number of uncertainties,” said Ron Hamburger, one of the country’s leading structural engineers. “We don’t have as many records, particularly for large magnitude earthquakes, as we would like.”
Previous earthquakes have revealed flaws with some skyscrapers. A widely used welding technique was found to rupture during the 1994 Northridge earthquake in Los Angeles. (Many buildings in San Francisco and Los Angeles have not been retrofitted.)
(Excerpt) Read more at nytimes.com ...
And people wonder why the cost of anyplace to live here is so high; you really can’t build ‘up’ in SF very easily, and you can’t build ‘out’ because the bay is already too filled in and the fill is potential quicksand.
It’s coming. The more high rises they build the more likely. It’s San Francisco so I say keep up the good work!
“I’m tellin ya, there’s so much crap on the sidewalks in San Fran that it’s gonna break off and slide into the sea.”
You know your city is a shirthole when the city hires people to go out and measure the shirt on the sidewalks.
What a crappy job.
Pass the popcorn please.
175 Bluxome. Banana Republic, owned by The Gap moved all their office workers out of the building in one day due to ‘structural integrity’. The company was growing fast and the amount of office space there was insufficient. Got out of their contract with the building owner. Got sued for slander. The new tenants were a bunch of small businesses leasing small portions of the building. That was 1987. In 1989 the earthquake hit. Building collapsed. 4 people died under all the bricks. Those folks did not have there resources to check out safety issues.
Now we need a way to insure that the risk of the next quake is not passed on to the entire country or world. Increase the premiums paid in Frisco or limit the outside exposure.
We don’t want the bad decisions to build and the billions and maybe trillions to sink the whole u.s.a.
The funny thing is if the big one hits, it’ll be the bums living in tents who are spared while those expensive towers come crashing down.
The real question is how big on the Richter scale would the earthquake have to be to displace all the crap and used needles on the sidewalks?
If you will excuse my little correction, your big problem is that you are built on a big, hulking set of plate edge related faults. Of course, you are correct about the joys of building on a fill soup. It’s going to be a tragedy.
You can get a degree in it from UC Berkeley.
They’re good decision-makers there in San Francisco. Don’t worry about a thing.
Not if the buildings fall onto the tents.
The Band Played On - Part II.
the Taipei 101 is only 600 feet from a fault line.
. The ginormous ball, of which the Burj Dubai has nine, was installed on in-place from 41 discrete steel plates because the combined weight of 730 tons would have been too heavy to lift by crane. The people even came up with a nickname for it: the Damper Baby. Don't look at me. The best I could come up with is some combination of “stabilizer” and “testicle”.
The beast awakens! a fun short video in the article. Might have to increase the rent, to cover the costs.
Famous Last Words
The name game—Hamburger is a structural engineer. :-)
I have actually met the guy. I attended a four hour forensic engineering presentation on the World Trade Center fires and collapse. He was the head of the three year forensic team that investigated the events.
That is astonishing!
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