Millennium Tower is tilting, sinking
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Millennium Tower is tilting, sinking
1–10 of 187 posts
Re: Millennium Tower is tilting, sinking
#2A fair warning that sinking doesn't just happen to towers: http://science.time.com/2012/05/21/soaring-to-sinking-how-bu...
Re: Millennium Tower is tilting, sinking
#3What is the risk? Does this make the building more dangerous because it's in an earthquake-prone area? Obviously this doesn't sound good, but the article mentions that there is no threat to safety of occupants. Is it merely aesthetic?
Re: Millennium Tower is tilting, sinking
#4I wonder what effect a medium to heavy earthquake would have on this building's foundation.
Re: Millennium Tower is tilting, sinking
#5I 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 problem compounds dramatically.
Re: Millennium Tower is tilting, sinking
#6What is the risk? Does this make the building more dangerous because it's in an earthquake-prone area? Obviously this doesn't sound good, but the article mentions that there is no threat to safety of occupants. Is it merely aesthetic?
This other article discusses how uneven sinking of the tower causes cracks and elevator issues: http://www.sfchronicle.com/bayarea/article/SF-s-landmark-tow...
> 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.
Re: Millennium Tower is tilting, sinking
#7My house is on a steep hill, and Seattle has a reputation for hills sliding away under heavy rain. Before building it, I hired 3 separate geologists to evaluate the site.
After digging holes, they said the site was sitting on "glacial till", which is clay that was compacted by about a mile of ice, and said there was nothing to worry about. Paying them was worth it for the peace of mind. (Turns out the till was so hard it could not be dug with hand tools.)
I did have a scare because a spring appeared on the edge of the property, as underground water is indicative of slide risk. Fortunately, it turned out to be a leak in the water main!
I still made sure the hard surfaces all drained into the storm drain, so that the hill wouldn't become saturated with water.
I can't conceive of building a 58 story building on sand in an earthquake zone. Reminds me of that Monty Python quote:
"When I first came here, this was all swamp. Everyone said I was daft to build a castle on a swamp, but I built in all the same, just to show them. It sank into the swamp. So I built a second one. That sank into the swamp. So I built a third. That burned down, fell over, then sank into the swamp. But the fourth one stayed up. And that's what you're going to get, Lad, the strongest castle in all of England."
Re: Millennium Tower is tilting, sinking
#8What is the risk? Does this make the building more dangerous because it's in an earthquake-prone area? Obviously this doesn't sound good, but the article mentions that there is no threat to safety of occupants. Is it merely aesthetic?
How much stock should one put in that declaration of safety? It is from an "independent" analysis... but who paid the analysts? Or, suppose absolute freedom from bias... how many times have expert opinions of safety been wrong in the face of mother nature. Picture Fukushima.
The risks in a tilting building are many. From a market value standpoint, homeowner value has already been destroyed simply by perception. If remediation is necessary here, homeowner fees could dramatically increase. Tilting buildings often see cracks in walls, malfunctioning elevators and other ills which also lower value. There will be lawsuits here-- you can see all sides rattling sabers with legalistic language and positioning already just from these articles -- and those will carry costs as well. Taxpayers may well be pulled into the fray and suffer as well in these situations.
From a pure safety standpoint, experience dictates that we should discount expert declarations of safety in many such matters. Residents of the tower and the towers' neighbors may do well to heed caution. At the end of the day, it is hubris to expect to predict with any high degree of confidence what might happen here. After all, none of the experts from any side involved foresaw even the current predicament, where no grand act of nature is even involved. The building simply stands there, yet already reacts in unpredicted ways. How likely are the experts then to foresee predicaments in even more complex situations?
Re: Millennium Tower is tilting, sinking
#9I 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…
How much would it have cost to dig down to bedrock, and pour a concrete foundation from the bedrock up to surface level?
Between the amount of sand to be moved and the amount of concrete to be poured, it sounds like an enormous fortune; I guess that the relevant questions are whether the market could bear it and whether it would be cheaper than the rapidly-developing lawsuits. It may be that the building didn't make economic sense in the first place, if it couldn't be built both safely and profitably -- which has unpleasant implications for the SF housing crunch...
Re: Millennium Tower is tilting, sinking
#10"To cut costs, Millennium did not drill piles to bedrock."
What are the implications for earthquake safety?