Despite initial progress in the first phase of the so-called fix earlier this year, the sinking and leaning Millennium Tower in San Francisco is now tilting more to the west than ever, according to monitoring data reviewed by NBC Bay Area’s Investigative Unit.
The tower is currently leaning more than 29 inches at the northwest corner of Fremont and Mission streets, much of the added tilt occurring during the digging needed to prepare to support the tower along two sides.
— NBC Bay Area
The data came from a rooftop monitoring system, which the fix’s chief engineer Ron Hamburger said was less reliable than the one contained in its foundation before stating the half-inch tilt recorded was "negligible."
A geotechnical engineer working on the $100 million project expressed his dismay to reporters, saying: "You spend all this money, but you still have an uncertain result long term."
The structure is leaning so much that some involved think it could potentially be red-tagged in the aftermath of a major earthquake, which the U.S. Geological Survey says has a 20% likelihood of occurring in the next 30 years.
21 Comments
Start dismantling the building. Reduce height to 1/3 its height right now. Maybe you might be able to go with 1/2 its height. Dismantling to 1/3 and finishing its height to about 45-50% of its current height will help with reducing the sinking and tilting. If I remember correctly, this building's piles were not going deep enough and soil not supporting it's weight so total mass needs to be reduced. The tilting needs to be addressed as well so strategic placement of additional mass at the lower floor levels just enough to stop the tilt.
Either that, or dismantle completely, redesign, and rebuild correctly.
Ricky... one does not simply dismantle a few floors off a multi-story high-rise. There is so much critical shit in the penthouse that it's very likely to be easier/cheaper/more reasonable to tear it down and re-build than it is to relocate infrastructure.
Of course. Dismantling doesn't mean just carelessly ripping off the penthouse equipment stuff. Removing it and then reengineer a new roof structure and penthouse at a lower height, and put the equipment back in as needed. Of course, you do take those into consideration. I agree it may be better and more reasonable to tear it down to the foundation, redesign, and rebuild.
Note: the redesign may have to be shorter and weigh less so the existing piles would work. Tearing those out may destabilize the soil more and cause issues to adjacent buildings so care and consideration or any other risk mitigation measures needs to be considered and applied but right now, it's a greater hazard to continue to leave this risk in place.
Therefore, I'm with you on that. Nothing about this whole shit situation is cheap but it falling over (due to tilting) will be very much worse. Politically, dismantling it down to the foundation and then rebuilding a new building on those foundations that are well within the weight limits so as to not sink or tilt (but otherwise a new building, would be better than not tearing it down and stopping the sinking and tilting... perhaps.).
I think the CIA should fly planes into it.
Might be too risky with that one.
Real-estate values have dropped quiet a bit in SanFran, businesses are evacuating. Probably not worth the cost to rework at this point and Plan A and B haven't done the job. Earthquake or not this building should be dismantled
I agree. I'd probably leave the grade/below grade foundation and piles but dismantle everything above. At least, at first. Careful analysis for removal of the foundations and piles would likely be need to be looked at before removing those as removal of those may destabilize the ground under immediate adjacent structures. It is a concern I would have regarding resettling of soil as those are removed. It's possible but it is tricky, and you don't want a strong earthquake happen during any stage of the process. Since we can't predict when such happens. Dismantling has its risks, too. However, it is a necessary risk because it is only a matter of time before the building falls over or something disastrous. You could argue that it was unnecessary for this ever to have to have happen and I would agree but now it's a risk to mitigate this risk situation versus the risk to not mitigate.
gentlemen, at this stage it's cheaper to just keep fortifying the building to bedrock - you just don't truncate a massive 60 story conc. building. That being said, time is running out, a 6.5 > 7.0 earthquake is becoming an increasing order of probability in the next 20 years
It's too late and they need piles that goes down two to maybe three times deeper than it currently goes down to. It's too late for that. It's time to tear it down. Maybe you can build a new building on site on existing foundation and yes, you can cut the concrete core down. It's been down before with buildings. It's the safest route since regular explosive demolition is too risky. So you need to take it down in sections in a careful manner.
Soil liquefaction will send this building on its ass killing hundreds or much more. It could happen AT ANY TIME! In 10 minutes.
it's been 10mins since your comment. Nothing happened. We're all in the clear.
I think if an earthquake happens, it could fall over but not entirely sure enough on how much time. It is an imminent risk because earthquakes and soil liquefaction poses that. Earthquakes can't be scientifically predicted as to the day, hour, and minute. At least, at this point in time with current science. The soil liquefaction that ajoso refers to will generally only occur from an earthquake. A tsunami may possibly saturate soil enough to do a similar effect. I'm more concerned with strong earthquakes but won't rule out tsunami events. An event on the scale of the 1906 earthquake could do the job. There's lot of variables.
Its going over soon. Mr sloppy Hamburger doesnt give a shit. Heavy mayo, no pickles. Its gonna flop over soon!
Andre Jaussaud
PHD
phd in what? foaming at the mouth dogshit?
I do not exactly understand the nonsense Ajoso just said but I do agree with the inherent concern about the building's continuing to tilt. Any building tilting is a sign of concerning issues. Even the leaning tower of Pisa's leaning has been a concern. The good thing is that other buildings were not built up close to the leaning tower of Pisa.
It was always known that it will eventually fall over but at the same time, effort is to continue to prolong it from falling over because, over time, it had become a tourist landmark that will end when the building is no more. Its luck was because of how long it took to build and the constant adjustments in the design and construction as the building was being built that in fact aided in prolonging it from falling over. If they just kept building like it was originally designed while knowing it was tilting, it would have fallen over.
Regarding this building in San Francisco, its tilting will continue until the piles are basically uprooted. When? I do not know nor going to predict. The risks associated with earthquakes and liquefaction only increase the concern.
I'll admit I giggled at Mr. Sloppy Hamburger.
Well that's true.
Y'all need better burger joints
Richard Balkins and Non Sequitur both work at the landfill in Antioch. Anyway. I own 60 million of properties and I know what im talking about.
LOL....
Look, DR Ron Cheeseburger knows his shit. If he says this bitch aint going over, then it AINT! Stop worring about it you lizzerd bellies! Go watch old Frasier shows and shut up!
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