Plan to Fix Sinking SF Tower About to Be TestedFebruary 2, 2018
Plans to permanently right the sinking Millennium Tower by retrofitting the building’s foundation with a series of new compression micropiles which would be drilled down to the bedrock below are about to be tested.
As proposed, three test micropiles will be drilled and filled down to a depth of up to 300 feet on the western sidewalk of Beale Street, adjacent to ‘The Residences’ portion of the Millennium Tower development at 301 Mission Street.
The test pile program is expected to be finished by the end of July. And if successful, the tested micropile design, or one that is similar, will be used to retrofit and stabilize Millennium Tower against continued settlement, according to the team involved.
But once again, exactly who is going to be on the hook for covering the cost of any fix and damages could take nearly a decade to resolve, with the Transbay Joint Powers Authority (TJPA) now named in nearly a dozen lawsuits related to the sinking Tower at 301 Mission Street which is adjacent to San Francisco’s new Transbay/Salesforce Transit Center.
We’ll keep you posted and plugged-in.
Comments from Plugged-In Readers
I am very happy to see it get fixed – hopefully before the next earthquake. And I know the developer wants to minimize the impact but calling some 300 feet long and 1 foot in diameter ‘micro’ is a bit cheeky. Especially when you have 50-100 of them. I swear these people would try to sell you a dead parrot claiming he is merely stunned and pining for the fjords…
Micro refers to both the diameter of the pile and the limited head height for installation. Typically anywhere from 2 to 4 feet in diameter and open sky available overhead. So yes, micro in this application.
They are micro compared to the regular, or large piles. It’s all relative.
It’s not the developer calling them micropiles, it’s the industry.
so does ‘retrofit and stabilize’ not entail ‘correction’ of the lean? as in they aren’t going to even try to straighten it out?
You’re inferring an outcome that wasn’t implied.
“Plans to permanently right the sinking Millennium Tower”
“To right” seems like it means a different outcome than “stabilize”.
We wouldn’t waste too much time trying to parse the language until the plan has been finalized.
The key takeaway, as we revealed above, is that a solution has passed the theoretical phase, the micropile approach is about to be tested and the testing should be completed by mid-year.
As BobN noted, it kind of was implied. By the headline.
First sentence, rather — not the headline.
I still like my plan better: build a hydraulic shaker in the basement level, of the kind that would be use to stabilize a building in a earthquake, turn it on, and sink the building down to bedrock. Then punch the entrance in on the 35th floor or whatever floor happens to be at grade.
Everybody’s an engineer…
Including the people who built the building. Sorta.
I think JWB is the type of engineer that thinks up carnival rides.
If they install the piles under the low side, they could allow settling to continue on the high side until it is closer to level, then finish installation of the micro piles. When engineers stabilized the Leaning Tower of Pisa, they removed earth from below the raised end of the foundation, encouraging the tower settle in that direction, thus correcting several degrees of tilt. A much bigger project, but I bet this principle still applies.
I believe that is the plan.
The testing will be done adjacent to the “City Residences,” not “The Residences.”
This outcome will be interesting to see — whether it will work or not. Assuming it does stabilize the building, the value of the units will still take since building fix is a retrofit (as opposed to building it right the first time.)
What is the construction noise going to be like?
Muffled, I would think.
there’s currently a 2/2 unit listed for about 1.4M, and it says the unit is in the “11-story mid-rise”. I didn’t realize the tower had a separate “mid-rise” building…is this separate building sinking too or is it free from sinking problems?
The mid-rise is the City Residences annex which is both referenced and pictured in the foreground above.
And why is the TJPA being sued when anyone knows that its sinking because the developer and the designer didn’t take into account the development planed for the area.
I guess that these fools just think the taxpayers have deeper pockets then the developers.
Why should we pay for their screw ups?
UPDATE: Plan to Stabilize the Sinking Millennium Tower Closer to Reality
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