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This article [0] makes the San Andreas big one seem relatively mild. California buildings are prepared for it and the fault is only capable of an 8.2 or so. Now

This article [0] makes the San Andreas big one seem relatively mild. California buildings are prepared for it and the fault is only capable of an 8.2 or so. Now Portland is overdue for a much worse quake... [0] https://www.newyorker.com/magazine/2015/07/20/the-really-big-one https://www.newyorker.com/magazine/2015/07/20/the-really-big...

wahern 7y ago
There've been recent suggestions that older, post-1950 buildings, which generally used welded joints now known to be inadequate, may not fair well or may even fail catastrophically. Older steel buildings used riveted connections, while newer buildings use improved welding techniques and, at critical points, bolting. Riveting is more resilient, while bolting is considerably stronger.
- Cshelton 7y ago
  It is even worse than that. I read an article and had discussions with my civil engineer friend. Many of the different techniques used to "Earthquake" proof a building, especially tall towers, vary a lot and have NEVER had a real life test. On top of that, the regulatory oversight in insuring the ACTUAL construction was done properly based on the plan, is... not great. So hypothetically, if a 8.2+ Mag hit SF... we know many buildings like soft first floors, anything not on bedrock, etc, will fall, but even the towers.. it is all based on models. We really don't know what will and won't happen. As some famous (forgot name) architect in SF said back in the mid 1900's, "Don't build anything over 100ft in SF, just don't do it".
  - ajmurmann 7y ago
    Earthquake risk comes up in discussions about reasons for not building taller. Meanwhile Tokyo has plenty of tall buildings and gets earthquakes all the time. I've never gotten a good explanation for this and don't know enough to judge if this is just another NIMBY excuse or legitimate.
    - wahern 7y ago
      The notion that we have no real-world experience with how modern skyscrapers behave in earthquakes doesn't pass muster, for exactly the reason you pointed out. Not only is the scientific research easy to find on Google, but we can see videos of events on Youtube: https://www.youtube.com/watch?v=7Zw-BvKo0pI https://www.youtube.com/watch?v=7Zw-BvKo0pI, https://www.youtube.com/watch?v=gglhWS23HfM https://www.youtube.com/watch?v=gglhWS23HfM The notion that bedrock is a requirement is also easily refuted by a simple search of the scientific literature. TL;DR: it's complicated, obviously, but one potential advantage of friction piles and a floating foundation is less movement. We don't need to be professional structural engineers to reject such simplistic, categorical notions; they're patently flawed.
    - arbitrary_name 7y ago
      It's not legit. There's techniques to build tall in earthquake prone areas; such as building on rollers (New Zealand has some interesting examples of this approach), framing techniques, etc.
- dehrmann 7y ago
  Don't oversell rivets. They replaced the lattice trusses on the western span of the Bay Bridge with box beams and bolts, in part because of rivets. The cool thing with hot rivets is they contract as they cool, so they tighten well. The major downside is the steel isn't hardened--bolts are.
- brudgers 7y ago
  For a building on the drawing board today, there's no difference. The loads are the loads. Bolted, welded or riveted,the joints are designed to resist the same forces. Moderately recent buildings are the same. When an engineered system is stronger, less is used.

wahern 7y ago

There've been recent suggestions that older, post-1950 buildings, which generally used welded joints now known to be inadequate, may not fair well or may even fail catastrophically. Older steel buildings used riveted connections, while newer buildings use improved welding techniques and, at critical points, bolting. Riveting is more resilient, while bolting is considerably stronger.

Cshelton 7y ago
It is even worse than that. I read an article and had discussions with my civil engineer friend. Many of the different techniques used to "Earthquake" proof a building, especially tall towers, vary a lot and have NEVER had a real life test. On top of that, the regulatory oversight in insuring the ACTUAL construction was done properly based on the plan, is... not great. So hypothetically, if a 8.2+ Mag hit SF... we know many buildings like soft first floors, anything not on bedrock, etc, will fall, but even the towers.. it is all based on models. We really don't know what will and won't happen. As some famous (forgot name) architect in SF said back in the mid 1900's, "Don't build anything over 100ft in SF, just don't do it".
- ajmurmann 7y ago
  Earthquake risk comes up in discussions about reasons for not building taller. Meanwhile Tokyo has plenty of tall buildings and gets earthquakes all the time. I've never gotten a good explanation for this and don't know enough to judge if this is just another NIMBY excuse or legitimate.
  - wahern 7y ago
    The notion that we have no real-world experience with how modern skyscrapers behave in earthquakes doesn't pass muster, for exactly the reason you pointed out. Not only is the scientific research easy to find on Google, but we can see videos of events on Youtube: https://www.youtube.com/watch?v=7Zw-BvKo0pI https://www.youtube.com/watch?v=7Zw-BvKo0pI, https://www.youtube.com/watch?v=gglhWS23HfM https://www.youtube.com/watch?v=gglhWS23HfM The notion that bedrock is a requirement is also easily refuted by a simple search of the scientific literature. TL;DR: it's complicated, obviously, but one potential advantage of friction piles and a floating foundation is less movement. We don't need to be professional structural engineers to reject such simplistic, categorical notions; they're patently flawed.
  - arbitrary_name 7y ago
    It's not legit. There's techniques to build tall in earthquake prone areas; such as building on rollers (New Zealand has some interesting examples of this approach), framing techniques, etc.
dehrmann 7y ago
Don't oversell rivets. They replaced the lattice trusses on the western span of the Bay Bridge with box beams and bolts, in part because of rivets. The cool thing with hot rivets is they contract as they cool, so they tighten well. The major downside is the steel isn't hardened--bolts are.
brudgers 7y ago
For a building on the drawing board today, there's no difference. The loads are the loads. Bolted, welded or riveted,the joints are designed to resist the same forces. Moderately recent buildings are the same. When an engineered system is stronger, less is used.