SF skyscraper has shifted 16 inches since completion

[brahmanknight]

I'm not gonna pretend to know a lot about skyscraper construction, but this is unsettling news.

http://www.foxnews.com/us/2016/08/01/swanky-san-francisco-high-rise-sinking-tilting.html

A newly built high-rise residential tower in San Francisco that's home to famed 49ers' quarterback Joe Montana and Giants' outfielder Hunter Pence is slowly sinking and shifting, and may ignite a court battle between residents and the city.

The 58-story Millennium Tower, located at 301 Mission Street just south of the city's financial district, was completed in 2008 and has sunk 16 inches and shifted 2 inches to the northwest since opening, according to a report issued by an independent consultant obtained by KTVU-TV.

The owners of the $350 million building told KTVU the construction next door of the Transbay Transit Center, a $4.5 billion project to serve as a hub of mass transit, has caused the ground movements.

In a response, the Transbay Joint Powers Authority said Monday that residents' claims against the TJPA are "misplaced; as demonstrated by data collected over more than seven years," adding that "full responsibility for the tilting and excessive settlement of the building lies with Millennium Partners, the developer of the Tower."

The transit authority also said the high-rise is made of concrete rather than steel, "resulting in a very heavy building. This heavy structure rests on layers of soft, compressible soil. The foundation of the Tower, however, consists only of a concrete slab supported by short piles that fail to reach the bedrock below. That foundation is inadequate to prevent settlement of a building with the weight of the Tower."

 

[Happy Hands]

I'm not gonna pretended to know a lot about skyscraper construction, but this is unsettling news.

 

[Bob the Citronaut]

#BanSkyscrapers

But seriously why don't the piers go down to bedrock? I thought that was pretty much SOP for tall buildings. Of course the building is going to settle.

 

[UCFRogerz]

 

[goodknightfl]

was it built by the weebles company? Weebles may wobble but they don't fall down.
I wouldn't want to be in it otherwise during a moderate earthquake.

 

[UCFRogerz]

For those wondering, like I was, this is roughly a 0.5 degree tilt assuming pivot on one end and 16" of sink on the other of the longest site. Translates to roughly 5' 7" of movement at the top of the 645' building.

 

[fabknight]

For those wondering, like I was, this is roughly a 0.5 degree tilt assuming pivot on one end and 16" of sink on the other of the longest site. Translates to roughly 5' 7" of movement at the top of the 645' building.

Thanks. That's exactly what I was wondering. Nerd.

 

[jetsaholic]

TL: DR

 

[fabknight]

For those wondering, like I was, this is roughly a 0.5 degree tilt assuming pivot on one end and 16" of sink on the other of the longest site. Translates to roughly 5' 7" of movement at the top of the 645' building.

I was actually wondering, given the degree of tilt and assuming pivot on one end, how much movement there is at the top during an earthquake measuring 7.2 on the Richter scale with the epicenter in San Francisco while the building was experiencing 140 mph winds in the direction of the tilt? I need that in common core math, please.

 

[Bob the Citronaut]

It had to have settled pretty level though. A floor even an inch out of level would be enough to cause me to jump out the window.

 

[UCFRogerz]

I was actually wondering, given the degree of tilt and assuming pivot on one end, how much movement there is at the top during an earthquake measuring 7.2 on the Richter scale with the epicenter in San Francisco while the building was experiencing 140 mph winds in the direction of the tilt? I need that in common core math, please.

11

 

[Good Knight Sweetheart]

I'm not gonna pretend to know a lot about skyscraper construction, but this is unsettling news.

http://www.foxnews.com/us/2016/08/01/swanky-san-francisco-high-rise-sinking-tilting.html

A newly built high-rise residential tower in San Francisco that's home to famed 49ers' quarterback Joe Montana and Giants' outfielder Hunter Pence is slowly sinking and shifting, and may ignite a court battle between residents and the city.

The 58-story Millennium Tower, located at 301 Mission Street just south of the city's financial district, was completed in 2008 and has sunk 16 inches and shifted 2 inches to the northwest since opening, according to a report issued by an independent consultant obtained by KTVU-TV.

The owners of the $350 million building told KTVU the construction next door of the Transbay Transit Center, a $4.5 billion project to serve as a hub of mass transit, has caused the ground movements.

In a response, the Transbay Joint Powers Authority said Monday that residents' claims against the TJPA are "misplaced; as demonstrated by data collected over more than seven years," adding that "full responsibility for the tilting and excessive settlement of the building lies with Millennium Partners, the developer of the Tower."

The transit authority also said the high-rise is made of concrete rather than steel, "resulting in a very heavy building. This heavy structure rests on layers of soft, compressible soil. The foundation of the Tower, however, consists only of a concrete slab supported by short piles that fail to reach the bedrock below. That foundation is inadequate to prevent settlement of a building with the weight of the Tower."

Obligatory:
"Thanks, Obama."

.

 

[Sir Galahad]

I was there last week working on some retail space and I asked the broker showing me around why would anyone live In a high rise in SF. His comment was something like they are engineered to withstand earthquakes. I told him I've seen all the movies, if it's not an earthquake it's Godzilla but either way, that building is coming down. I guess I was right.

 

[UCFRogerz]

I was there last week working on some retail space and I asked the broker showing me around why would anyone live In a high rise in SF. His comment was something like they are engineered to withstand earthquakes. I told him I've seen all the movies, if it's not an earthquake it's Godzilla but either way, that building is coming down. I guess I was right.

Did you then fly away in your jet pack while cackling and throwing benjis?

 

[EweSeaEff]

Actually, the area where that building was built is designated by the USGS to have "very high liquefaction susceptibility". Not only that, but the area where the Millennium Tower was built was originally part of the San Francisco Bay that was infilled 150 years ago.