The tilt of San Francisco’s Millennium Tower has deepened as engineers work to reverse lean

[Kamaji]

The tilt of San Francisco’s Millennium Tower has deepened as engineers work to reverse lean

By Katherine Donlevy   
June 11, 2023

It’s the leaning tower of San Francisco.

The Bay Area’s Millennium Tower has only continued to tilt further and sink deeper west in spite of architects’ best efforts to steady the ritzy building.

The multimillion-dollar-per-unit tower is now leaning more than 29 inches at the corner of Fremont and Mission streets — a slant over half an inch deeper than previously revealed, according to monitoring data reviewed by NBC Bay Area’s Investigative Unit.

The half-inch tilt was reportedly gained while engineers dug beneath the sinking condominium earlier this year to support the weight of the tower — which was built atop a former landfill — along its two sides.

Fix engineers saw progress in stabilizing the Millenium Tower’s north side along Mission Street after implementing six concrete-filled steel piles along its base in January, but it may have come at a cost to the tower’s west side, the data shows.

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Source:  https://nypost.com/2023/06/11/san-franciscos-millennium-towers-tilt-deepens-as-engineers-rush-to-reverse-lean/

[Kamaji]

Wouldn't it be better to just take the building down?

[PeteS in CA]

5 or 10 years ago I rooted around the Internet trying to learn whether the Millennium Tower was on pre-Spanish-colony land or on post-Gold-Rush landfill (landfill was being done as early as the 1850s). As best I could tell from comparing maps, the building is near where land ended and landfill began. I doubt that being on old shore land, landfill or half each would be a good choice. But SF politics ...

[Wingnut]

Wouldn't it be better to just take the building down?

It is not IF it will fall down but when it will fall down. 

[libertybele]

Is there anything in San Fran that isn't a disaster??

[Kamaji]

It is not IF it will fall down but when it will fall down. 

That's what I'm figuring.

[DB]

Won't likely take a very big quake to cause major damage.

[Fishrrman]

The [many] comments at the original NY Post article are worth reading.

The more they try to "fix the problem", the worse the problem seems to be getting.

Not more than a few months ago, "the tilt" was 24" -- now it's 29" or so.

There's a guy with an architectural background on Youtube that has posted a piece or two on the Millennium Tower. He posts under the name "Building Integrity".  I believe the original pilings under the building went down only about 150 feet (in ground that is essentially "landfill"), whereas "bedrock" is about 250 feet down.

The idea was "more [but shorter] pilings". Then, they made an additional design change (again, to save money) -- build the tower out of concrete instead of steel frame construction (concrete is heavier). So... heavier weight + short pilings = tilt.

I'm thinking that even a mild earthquake could introduce an additional measure of instability, that could topple it right over in one piece, 53 stories tall. This won't be like the World Trade Center coming down.

Even if they could get additional support under it NOW (which I think is what they're trying on one side)... how are they ever going to "right it"?

Best remark in the Post's comments:
"They're fighting a loosing battle. This building will be condemned soon."

They're going to have to tear this one down.
Or... it's going to FALL down.

Choose.

[DB]

The [many] comments at the original NY Post article are worth reading.

The more they try to "fix the problem", the worse the problem seems to be getting.

Not more than a few months ago, "the tilt" was 24" -- now it's 29" or so.

There's a guy with an architectural background on Youtube that has posted a piece or two on the Millennium Tower. I believe the original pilings under the building went down only about 150 feet (in ground that is essentially "landfill"), whereas "bedrock" is about 250 feet down.

The idea was "more [but shorter] pilings". Then, they made an additional design change (again, to save money) -- build the tower out of concrete instead of steel frame construction (concrete is heavier). So... heavier weight + short pilings = tilt.

I'm thinking that even a mild earthquake could introduce an additional measure of instability, that could topple it right over in one piece, 53 stories tall. This won't be like the World Trade Center coming down.

Even if they could get additional support under it NOW (which I think is what they're trying on one side)... how are they ever going to "right it"?

Best remark in the Post's comments:
"They're fighting a loosing battle. This building will be condemned soon."

They're going to have to tear this one down.
Or... it's going to FALL down.

Choose.

The added supports are only 24" wide going down 250'... It doesn't take much shift of the land fill to completely buckle it, particularly with a little liquification...

[Cyber Liberty]

They're going to have to tear this one down.
Or... it's going to FALL down.

Choose.

I guess it depends on whether the inhabitants are rich or poor...

[DB]

I guess it depends on whether the inhabitants are rich or poor...

Apparently very rich.

[PeteS in CA]

Wouldn't it be better to just take the building down?

Hypothetically, yes. But the Tower is not a 1/2-3/4 empty office building with one commercial real estate company owning it. In addition to the obvious expense of and risks inherent in demolition and the the months of disruption in the neighborhood, the Tower is condominiums, with hundreds of owners. Those owners will need to be compensated for their loss and moving expense, and they will be after every company that had a hand in designing and constructing the Tower ... and bankruptcies will complicate matters, probably bringing liability down on the City of SF. Ultimately, it would be better for the city to bite the bullet and get moving on the compensation and demolition processes, but Kick-the-Can-Down-the-Road politicians don't think in terms of decisive actions and actually solving problems.

Won't likely take a very big quake to cause major damage.

The SF Bay Area experiences not-very-big earthquakes - magnitudes 2-5 - pretty much every month or three. It's going to be a matter of years or even a couple of decades before the Millennium Tower gets to the point where a not very big quake would bring it down.

[DefiantMassRINO]

That is why you should drive the pilings ALL THE WAY to bedrock.

[Kamaji]

That is why you should drive the pilings ALL THE WAY to bedrock.