Sinking skyscraper in San Francisco

[throwittoblythe]

Would a two-inch lean at the top of the building actually make a marble roll toward the low side? Seems like that is more an issue of whether the floor itself is level. The marble probably rolls the other way in other rooms and on other floors.

That's doubtful. The OP said the building is leaning 2" out of vertrical over 645'. That's an angle of .01 degrees. Likely not something the human body can even discern.

It sounds odd, but if it's settling uniformly, that's much better than leaning, of course. I'm a licensed Civil Engineer myself, but I haven't taken the time to read into this particular case. It'll surely make the next round of "engineering f ups" on the History Channel.

One might argue that it's more stable in an earthquake if it's sunken into the ground, no?

 

[throwittoblythe]

Something I also find interesting is that the 800 foot tall 181 Fremont building in this photo has no central reinforced concrete core for the elevators. It's literally just steel frame throughout, all the way up to the top.

Wood construction is making a comeback, as well. Lamination of wood has been a hot topic of research and engineers are finding ways to build stronger beams with wood. I believe there is an 80 story wood tower building planned in London.

 

[CtownCyclone]

That's doubtful. The OP said the building is leaning 2" out of level over 645'. That's an angle of .01 degrees. Likely not something the human body can even discern.

It sounds odd, but if it's settling uniformly, that's much better than leaning, of course. I'm a licensed Civil Engineer myself, but I haven't taken the time to read into this particular case. It'll surely make the next round of "engineering f ups" on the History Channel.

One might argue that it's more stable in an earthquake if it's sunken into the ground, no?

Out of level, or out of plumb?

 

[somecyguy]

Wood construction is making a comeback, as well. Lamination of wood has been a hot topic of research and engineers are finding ways to build stronger beams with wood. I believe there is an 80 story wood tower building planned in London.

Interesting. How do they make it fire-repellent? Otherwise, that would be one big torch.

 

[throwittoblythe]

Out of level, or out of plumb?

Good catch, "out of vertical" is what was stated. So, it's leaned two inches in one direction. The angle is correct, though.

 

[throwittoblythe]

Interesting. How do they make it fire-repellent? Otherwise, that would be one big torch.

Science! I don't know specifically, but I believe there are fire-retardant chemicals that are used. It's certainly something that has to be considered, but wood structures are gaining more support (pardon the pun) in the industry.

 

[CtownCyclone]

Good catch, "out of vertical" is what was stated. So, it's leaned two inches in one direction. The angle is correct, though.

That's what us licensed mechanical engineers do - keep you dirt doctors in line.

But I do agree, 2" out is nothing over that distance. Wouldn't the building sway more than that in the wind?

 

[weR138]

Interesting. How do they make it fire-repellent? Otherwise, that would be one big torch.

Not really, the structural timbers don't typically fail in fires but floors and roofs do. Anyway, we already fire protect steel with gypsum board or spray on fire retarder or sprinkler system. Going to an enhanced structural timber wouldn't be much of a stretch from what we do now.

 

[throwittoblythe]

That's what us licensed mechanical engineers do - keep you dirt doctors in line.

But I do agree, 2" out is nothing over that distance. Wouldn't the building sway more than that in the wind?

That's most engineers for you "I got the right answer, but screwed up the communication."

My background is not in structural engineering, so I'm not sure what magnitude of movement those buildings have in the wind. I know when the Sears tower was opened, the residents complained because their pictures were swaying on the wall. Turned out their pictures were not moving, the building was.

I know buildings in seismic areas are designed with dampers. So, they are designed to move during an earthquake, but not fall over. Tai-Pei 101 has a huge damping weight that they made part of the architecture, which is pretty neat.

The fact that the building is settling (sinking) is upsetting to residents, no doubt, and it should be. However, that does not mean the building isn't structurally sound.

 

[BoxsterCy]

https://architecturefarm.wordpress.com/2016/09/15/floating-foundations-out-west/

From Tom Leslie in the Architecture Dept.

Lordy, even the architects at Iowa State talk and think like engineers.




Said the landscape architect who sold out and became a project manager for the Corps of Engineers.

 

[isume6]

Solution:

Oh, many good memories from my two years in Storms......although was fun to watch it blow up too!

 

[Doc]

This is why I like to design things people don't live in. Although I have had to deal with liquefaction some. that **** is wack

 

[sdillon500]

Would a two-inch lean at the top of the building actually make a marble roll toward the low side? Seems like that is more an issue of whether the floor itself is level. The marble probably rolls the other way in other rooms and on other floors.

Funny you should ask:



I lived in SF during the construction and completion of the tower (live across the bay in Oakland now), so this story has been fascinating to watch. Since this was (before the whole sinking/leaning issue) the most expensive/exclusive housing in the city (Hunter Pence & Joe Montana had apartments there), the residents immediately lawyered up and everybody's planning to sue the **** outta everybody else. Residents are blaming Millenium Properties, Millenium Property is blaming the Transbay Terminal that's digging the underground train station next door, Transbay Terminal is blaming Millenium Property, the city is investigating the planning department... It's great drama, and a pretty perfect metaphor for SF/Silicon Valley hubris right now

 

[Buster28]

Somebody actually bought the penthouse for a "very reasonable" $13 million.

But, damn - those views....

http://blog.sfgate.com/ontheblock/2...house-sells-for-a-very-reasonable-13-million/

 

[DurangoCy]

Wood construction is making a comeback, as well. Lamination of wood has been a hot topic of research and engineers are finding ways to build stronger beams with wood. I believe there is an 80 story wood tower building planned in London.

Sounds awesome