SF Tower settlement Part III 18

[dik]

thread815-412357
thread815-470048

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[dik]

Sorry hokie... not quite what I meant... was the original design predicated on 'real engineering'? or was there an error? From the end result, it's obvious that something else happened... it's like the Transcona grain elevator issue... as my late thesis advisor said, "Russia knows that Winnipeg is slightly west of Transcona."

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hokie66]

I did not know of Transcona, but righting that structure was impressive.

 

[dik]

Yup... and it's still there... or one similar to it. I haven't done a search for it... but I suspect Transcona will give you more hits. There used to be a large photo of it on one of the walls in the old engineering building at U of M. I think it was the first recorded failure in the mode suggested by Terzahgi.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Sym P. le]

A paper on Transcona grain elevator. That was a massive chunk of concrete to tilt. From page 804, clay depth of 52 to 55 feet generally except a ridge of boulders up to 12 feet high along the east edge. As the structure was filled with grain, the settlement became uneven and the clay started to flow.

 

[dik]

As hokie noted, righting it was quite a feat... I didn't know there were boulders on the east edge.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Walnuts]

Dik, in answer to your question about the original design: clearly there was an error in it! The design likely may have worked for the original steel-framed structure with 4 or 5 basement levels, but then they switched to a concrete frame and moved the basement parking to the adjacent building. At that point it should have been obvious that the Old Bay Clay, which starts down at 100 feet, below the sand layer in which the piles are tipped, would be pushed back on to its "virgin consolidation curve". Only recently I saw the calculation made by the original geotechnical firm which way underestimated the potential load on the Old Bay Clay. I don't know whether that was just an honest mistake or whether it was done intentionally to justify not switching to piles to "bedrock" since time pressure was driving all these changes, but regardless, it was a bad mistake.

 

[dik]

It was not an unusual experience, then. The Transcona grain elevator failure was a new thing, and not anticipated...thanks, Walnuts

I'm not big in seismic, but one of my biggest concerns would be the liquifaction of the founding clays/fill.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Pud]

Hi all,

Not structural but have been following this thread with a sort of macabre fascination.

I have a question: Assuming the building is righted, surely by reason of it's history it has already become unsellable?

Politicians like to panic, they need activity. It is their substitute for achievement.

 

[spsalso]

Units are sold, not the building. If you lower the price enough, they will sell.

Between this and the windows failing, the design and construction quality could certainly be brought into discussion, and well could get new purchasers wondering at other unfound failings. Not to mention the found ones required to be reported to the buyer by the seller. These could be bargaining points for someone considering purchase.

I believe there have been insurance payouts to assorted persons and entities. Note that it's possible that a payout to an existing condo owner could possibly mitigate or eliminate loss caused by a low selling price.


spsalso

 

[Walnuts]

Spsalso, the homeowners who participated in the lawsuits each received approximately $1 million under the settlement agreements. That might have made them happy at the time, but they were also promised a Fix that would work, so I guess that they are now longer so happy. But the $1 million each is an important part of the story. That is why the board of the HOA signed off on the Fix, and likely is why the four engineers who now comprise the EDRT and the DBI also signed off on it, because they didn't want the deny the homeowners their million bucks. Because they signed off on it, they now do not want to admit that they made a mistake. But now there is another problem. Because of first Covid and now layoffs in the "high tech" segment of the economy, demand for expensive housing in downtown SF has fallen quite a bit. Both Google and Facebook had built up large staffs in SF. Even before that, sales were slow to non-existent because sellers could not get their asking prices.

 

[dik]

Is there any sort of mechanism in place that prevents condo unit owners getting 'stuck' with the repair bill?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Walnuts]

Dik, the settlement agreements provided $100 million for the Fix and certain other repairs and upgrades. Also, Millennium Partners, the original developer, took out bonding / insurance policies on the design team and the contractor. All that to protect the homeowners from future assessments to pay for the Fix. How that is working out I don't know, but as a minimum I can see future lawsuits from the insurers to recover the monies that they are reportedly paying out because of the incompetence of the design team and the contractor. And the homeowners are going to be left with a tilting building!

 

[hokie66]

The joy of buying units. When things go wrong, all suffer.

 

[JAE]

Just FYI - last Friday the Wall Street Journal included in their Friday "Mansions" section a unit from this tower - top floor I think. The guy paid $13 million for this top floor penthouse and is now asking $14 million. Apparently he purchased the unit AFTER all the news came out about the leaning/sinking, suggesting in the article that he could make some money once the problems were solved.

I'm not sure a $1 million profit is anything to scoff at but if you read the mansion section you see all sorts of houses going for 20, 30, 100 percent more than paid for a few years ago. Going from 13 to 14 million doesn't seem like much of a profit considering the risk.

 

[Murph 9000]

@JAE Probably not much better than just breaking even after legal fees, condo fees, taxes, etc are deducted. With high interest rates, possibly even effectively a small loss.

 

[hamjohn]

SF's Millennium Tower now tilting more than ever to the west after early recovery

https://www.nbcbayarea.com/investig...ver-to-the-west-after-early-recovery/3249103/

 

[Mark R]

Is it just me or does 0.25" at the foundation seem like more than what the top moved because of the distances involved? It's still tilting more and no matter how you look at it!

 

[dik]

Still no soft cushy feeling... the 1/4" could be thermal for a building of that height... I think foundation based settlement measurements would be more appropriate... Whatever method, if they are not done correctly have about equal parts validity. I like Pike's comments, but this is a bit out of my league...

If it has to be razed, are the condo owners on the hook? including the cost for demolition?

With buildings, it seems if they fall down and kill people, those responsible are never charged.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Tomfh]

Isn’t that a worry if the building’s still moving but the new footings aren’t?

 

[hamjohn]

Revision to PA 2021-0719-4668.Increase size of bearing plate on high strength threaded rods to accommodate 1,000 kip jacking loads.

https://dbiweb02.sfgov.org/dbipts/default.aspx?page=PermitDetails