This brings me back to a question I have frequently asked myself: What do you do with unsafe or old skyscrapers? How would you raze such a thing? What if it falls over, breaks apart or breaks in on itself (9/11 gives an idea)? To a layman (with slight acrophobia) skyscrapers seem pretty fragile, and I'd much rather have them built into the ground than towards the sky, but obviously they're holding up in general and I…
Millennium Tower is tilting, sinking
81–90 of 187 posts
Re: Millennium Tower is tilting, sinking
#82Earlier quoted context omitted.
There is no scenario in which a 350 million dollar skyscraper deemed "not a safety issue for residents" will be torn down so they can "try again". They'll find a way to stabilize it and that will be that. No one is going to tear down nearly half a billion dollars worth of skyscraper if there's any chance of salvaging it.
It's not without precedent. In Seattle a cost-cutting method was used to build a 25-story downtown apartment building in 2001. In 2010 it was found to be flawed and unfixable, and so it was dismantled. And now there's a new building being built on the site. http://www.seattletimes.com/seattle-news/9-year-old-belltown...
Key there is it was deemed unfixable. $350 MM can do a lot of fixing.
Edit: To be clear, I'm not denying the entire possibility. It's just extremely unlikely, especially given that the tower is currently deemed safe.
Re: Millennium Tower is tilting, sinking
#83Earlier quoted context omitted.
I was wondering the same thing, but Google street view (taken in 2014) doesn't show any evidence of such a big dip. How is that possible?? The only thing I can think of is that it's more of a "sag," where the middle has sunk 18" but the edges haven't moved much, but I'm not really satisfied with that theory. https://www.google.com/maps/place/Millennium+Tower+San+Franc...
It's extremely unlikely that the building is sinking and the surrounding area is stable. More likely the building is pulling the entire area down, so it's probably hard to detect as a pedestrian.
A commenter upstream reports seeing the sidewalk being repaired multiple times throughout the last 10 years as well.
Re: Millennium Tower is tilting, sinking
#84I wonder what effect a medium to heavy earthquake would have on this building's foundation.
Probably not good. According to this and other articles, the building's concrete slab foundation sits roughly 80 ft below street level upon sand, while bedrock lies 200 ft down. That means there is 120 ft of sand, possibly susceptible to liquefaction, between the buildings foundation and solid bedrock. That sounds bad enough. But now imagine the building is tipping over slightly. The already potentially worrisome pro…
The SF Chronicle article that this Curbed article seems to be sourced from provides more information on this.
And while Stanford’s Deierlein doesn’t consider the sink or tilt a safety issue,
he did say, “I would be concerned for my investment.” That’s because a shifting
building can cause walls to crack, elevators to malfunction and all manner of
other annoyances.
P.J. Johnston, spokesman for tower builder Millennium Partners and its principal
owner, Sean Jeffries, said a nine-month, independent structural safety review in
2014 “determined the settlement has not significantly affected the seismic
performance of the building, and does not represent a safety risk.”
I think this link is paywall-free: http://www.sfgate.com/bayarea/article/SF-s-landmark-tower-fo...
Re: Millennium Tower is tilting, sinking
#85Earlier quoted context omitted.
Or one could just live in a place geologically suited for human habitation, such as the northeastern United States.
Yeah, but then you'd have to live in the northeast.
Tell me more about why the place you live is better than every other place in the world...
Re: Millennium Tower is tilting, sinking
#86Re: Millennium Tower is tilting, sinking
#87From the article: "To cut costs, Millennium did not drill piles to bedrock." I'm amazed that a building of that height would be built on a slab with friction piles in the mudflat fill zone of the SF bay. How did they get a building permit for that? 16 inches of sinkage in 8 years is huge. Building sinkage isn't all that unusual, but not for skyscrapers. There was a time when skyscrapers were only built on competent r…
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Re: Millennium Tower is tilting, sinking
#88Earlier quoted context omitted.
It's not without precedent. In Seattle a cost-cutting method was used to build a 25-story downtown apartment building in 2001. In 2010 it was found to be flawed and unfixable, and so it was dismantled. And now there's a new building being built on the site. http://www.seattletimes.com/seattle-news/9-year-old-belltown...
Key there is it was deemed unfixable. $350 MM can do a lot of fixing. Edit: To be clear, I'm not denying the entire possibility. It's just extremely unlikely, especially given that the tower is currently deemed safe.
Plus if it turns out to have been caused by the Trans Bay Terminal, they have very deep pockets (they supposedly spent $58 million on a buttress to protect the Millineum Tower). As does the developer, Millennium Partners and the engineering from firm's insurance companies.
This will get fixed. There will just have to be a big fight to see who has to pay.
Re: Millennium Tower is tilting, sinking
#89Earlier quoted context omitted.
What here is misinformation?
A few examples: - Foundations of tall building must go to bedrock - not true. - Large buildings settling is unusual - not true. - Earthquake safety has been compromised in this case - not true. The structural engineering of tall buildings is complex. Multiple large engineering firms were involved in the design and construction of this building. Curbed (owned by Vox BTW) took the SF Cronicle article and cut out the mo…
It seems that you need to read more carefully and perhaps with more generosity.
> A few examples: - Foundations of tall building must go to bedrock - not true.
I see few if any comments here asserting, let alone asserting without qualification, that buildings must be built to bedrock. Further, heeding your own advice that expertise should be bidden, note that the apparently expert sources in the article said themselves that not building to bedrock can be a problem.
I see people here noting and reflecting that expert opinion. Few if anyone going beyond it. And you're not reading the source material carefully enough if you miss the take that not building to bedrock can carry some risk.
> - Large buildings settling is unusual - not true.
Again, I see no one or very few people here saying this. Of course buildings settle over time. And here in this thread, contrary to your blithe and dismissive assertion, we even have people pointing out that settling happens not just in towers but in buildings of most any kind.
Note as well, again, that the very experts you appeal to say that this tower's settling is both comparatively fast and that its magnitude is unexpected. These are the experts talking, so you come off as hypocritical at best here. The nature and particulars of the settling in this particular case appears noteworthy and to be a reasonable cause for concern.
> - Earthquake safety has been compromised in this case - not true.
Ahh... so, now you are the expert and capable of refuting this possibility so entirely-- upon merely a cursory examination of second- or third-hand information, rather than a primary analysis, no less-- that it is somehow faulty for people to question whether this might have an impact on earthquake safety? My, my; odd that you called for caution in drawing conclusions until experts had weighed in, then turned around and flatly conclude that which I doubt even experts would leave completely unqualified, and certainly not universally and unanimously so.
The comments here so far are not much of the chicken-little or even rabble-rousing type. Try being more respectful toward your fellow community members.
Re: Millennium Tower is tilting, sinking
#90Earlier quoted context omitted.
Yeah, but then you'd have to live in the northeast.
Tell me more about why the place you live is better than every other place in the world...
Well, Phoenix is about as geologically stable as it gets, but we get hell on earth hot in the summer months, vs. hell froze over cold.