Posted on 06/11/2023 10:35:32 PM PDT by lowbridge
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.
Rooftop-based monitoring data — which is based on rooftop measurements and foundation-based determinations — indicates the tower shifted nearly an inch to the west compared to its tilt before it was supported on the north side.
Engineers in charge claim the data may not be reliable, despite pointing it to as proof of success earlier in the first phase of the project.
Project engineer Ron Hamburger told NBC in a statement that the rooftop figures are prone to weather fluctuations and said purely foundation-based data is more reliable.
The foundation-based digits also show that the tower is tilting more toward the west than ever, but only by about a quarter of an inch — a lean Hamburger claimed was “negligible.”
“We are fully confident that following transfer of the remaining design load to the piles,’’ Hamburger said, adding that “there will be no further … movement of the roof to the west.”
(Excerpt) Read more at nypost.com ...
I had a friend who was a civil engineer in Norfolk, VA. He told me that they drive piles until they stop moving a certain deflection per hammer strike. You do not need bedrock.
The piers on the Brooklyn Bridge sit on clay. They ran out of money about two thirds of the way to bedrock, and the clay is compacted as hard as rock under a couple hundred feet.
Good one!
Hmmm....maybe that was like the original team.
The real problem as I u defer and it is they convinced themselves that they did not need to place sufficient anchors down to bedrock but instead took a less extensive and therefore less expensive option
Heeling to Port...Heeling to Port If your USN, you’ll get it.
the brooklyn bridge is not built on landfill and does it weigh nearly what this tower does. Spent hours one day talking about this topic with a PhD engineering friend. Turns out in this case you do need to go to bedrock. oops!
Dump Viagra on it and hope it stays up more than 4 hours.
And check out the bit about the density bonus program.
Tearing it down would be the prudent thing to do.
Crappy soil, crappy foundation , earthquake zone = three strikes
Solving this problem, if it's solvable, only means architects will be more incentivized to build things more shoddily, figuring once again that someone else will fix the problems after it's built.
1, What was the name of he work foreman in charge of building the Leaning Tower of Piza...?
2..And are there any of his ancestors that would like an all expanses paid visit to San Francisco
Here is perhaps the definitive engineering analysis of the fiasco that is the Millenium Tower. I have concluded that there is no fix. There will be a slight earth quake and the damn thing will fall over.
https://www.youtube.com/watch?v=Xezg8PxVSYA&ab_channel=BuildingIntegrity
There are drilling machines (and I imagine pile drivers) that can be taken apart and hand carried
Pile driver:
Drilling rig
Good reference.
I have a Rule 9 T-Shirt. (Never go anywhere without a knife)
As much as possible I live that rule, even stopping to buy a cheap knife when I travel by air. Throw it away at the airport on the way home.
I was wearing that shirt in a gas station the other day when a employee commented on my shirt. He said to him, carrying a knife means an extra dollar an hour.
He interviewed for a job and was asked if he had a pocketknife on him. He said he did and always carried one. The employer boosted his pay because he knew that he had someone who knew how to think and use tools.
There are several other buildings in the area that have also been supported this method(friction pilings). Yes, it is on landfill. So, is the entire BACK BAY section of Boston. Where the 55 story Prudential Center and the 60 story John Hancock building have sat since the 1970s. The difference being in Boston that the Charles River Back Bay had SOLID ROCK underneath it.
The original ground underneath the tower in San Fran is on the land fill from the earthquake that destroyed the city in 1905.
The original ground/bedrock was 200 feet below the current street level. So, they used friction pilings. A method that had been employed by many other structures in the area.
FYI, many parts of Manhattan are also landfill. That is why the really tall buildings are at the southern tip where the Twin towers once stood and from 23rd street(Empire State Building) and up through mid town. Greenwich Village buildings are only 4 stories high because the ground underneath there was wetland back in the 1600s. It is all landfill.
It only has two sides? I miss when reporters knew English.
I wonder how many people have found perfect perches for cameras that are recording 24x7 to capture the epic collapse should it eventually fall over? If I lived nearby, I sure would.
A 6.0 or higher earthquake should solve this problem permanently.
Eastern cities have much more room for error with their minimal earthquake risk.
This building is going down—a major earthquake will hit long before they are done tinkering with it.
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