16 inches over 8 years is absolutely insane. That's the Usain Bolt of a sinking building.
Millennium Tower is tilting, sinking
41–50 of 187 posts
Re: Millennium Tower is tilting, sinking
#42...2 inches for such a tall building is such tiny angle If it sinks does this mean the first floor is slightly below the street level ..it probably means that the areas around the door and where the concete meets the street are cracked
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...
Re: Millennium Tower is tilting, sinking
#43Perhaps they can turn it into a tourist attraction. It has worked out well for Pisa.
Re: Millennium Tower is tilting, sinking
#44The article doesn't talk about the how this practically affects the entrances to the building. Do the doors have to be adjusted for such a drastic sinkage, or are buildings somehow designed so this isn't noticeable to the public?
Seems to imply they had to do something to the entrances, but not what. Maybe there are little ramps added every year? I'm gonna go look now.
Please take some pictures and share them with us.
Another article I read said they have needed to make adjustments to the first floor interface but didn't say what they were.
Re: Millennium Tower is tilting, sinking
#45Earlier quoted context omitted.
The real problem with digging down to bedrock is destablizing the building. Though there may be enough redundancy in the pilings to do it one at a time.
I think the question was why the builders didn't do it in the first place.
You dig down 200 feet to the bedrock, pour a foundation, and then pour pilings up to the surface to put the building on.
Re: Millennium Tower is tilting, sinking
#4616 inches over 8 years is absolutely insane. That's the Usain Bolt of a sinking building.
Reminded me of the Mandalay Bay incident some years ago. Apparently they tried to cheap out and use a previous soils report from an adjacent area.
> The tower was sinking ½ to ¾ inches a week
http://traveltips.usatoday.com/mandalay-bay-history-10712.ht...
Re: Millennium Tower is tilting, sinking
#47From 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…
How did it get approved? The developer's lobbyist and PR rep is former mayor Brown's spokesman and personal friend, and at the time the current mayor was Newsom, a product of Brown's machine. Newsom was a bit of a crook in the area of real estate, having some self-dealing while he was on the board of supervisors and making sure all of his friends' problems got cleared.
The same lobbyist also represents the Warriors in their current Mission Bay proposal.
Re: Millennium Tower is tilting, sinking
#48Makes me a little thankful (for once) that my Georgia home is built on a hill of dense, unyielding clay.
Dense clay might be unyielding, but depending on the plasticity of that clay you could be facing serious issues with heaving when the soil gets extremely moist.
Re: Millennium Tower is tilting, sinking
#49Lots of misinformation in this thread. Would be great to hear from a professional.
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 more reasonable paragraphs (such as that same Stanford they quoted saying he "doesn’t consider the sink or tilt a safety issue".).. And of course the Chron article already probably skewed it to make it more exciting.
I always shake my head when I read article on a subject that I happen to be be an expert. I'm sure experts in the engineering of these sorts of projects could teach us alot about this situation.
Re: Millennium Tower is tilting, sinking
#5016 inches over 8 years is absolutely insane. That's the Usain Bolt of a sinking building.
And the article mentions it was 10 inches in only (it's first) 2 years after completion!