Posted on 10/24/2016 1:32:26 PM PDT by LRoggy
SAN FRANCISCO (AP) -- Pamela Buttery noticed something peculiar six years ago while practicing golf putting in her 57th-floor apartment at the luxurious Millennium Tower. The ball kept veering to the same corner of her living room.
Those were the first signs for residents of the sleek, mirrored high-rise that something was wrong.
The 58-story building has gained notoriety in recent weeks as the "leaning tower of San Francisco." But it's not just leaning. It's sinking, too. And engineers hired to assess the problem say it shows no immediate sign of stopping.
"What concerns me most is the tilting," says Buttery, 76, a retired real estate developer. "Is it safe to stay here? For how long?"
Completed seven years ago, the tower so far has sunk 16 inches into the soft soil and landfill of San Francisco's crowded financial district. But it's not sinking evenly, which has created a 2-inch tilt at the base - and a roughly 6-inch lean at the top.
By comparison, Italy's famed Leaning Tower of Pisa is leaning more than 16 feet. But in a major earthquake fault zone, the Millennium Tower's structural problems have raised alarm and become the focus of a public scandal.
Several documents involving the downtown building were leaked in recent weeks, including exchanges between the city's Department of Building Inspection and Millennium Partners, the developer. They show both sides knew the building was sinking more than anticipated before it opened in late 2009, but neither made that information public.
(Excerpt) Read more at hosted.ap.org ...
If the Chinese are smart, they’ll just wait until it sinks into their own back yard.
I know some smart old money on the side of the hill in Berkeley that is right next to the Hayward fault. It will not be pretty.
LOL love that sketch
Even if it falls over from leaning?
If piles aren’t driven to bedrock, they are driven to a “level of resistance” or “refusal” (refusal to advance). The level of resistance is a function of the hydraulic hammer force and blows per inch of advancement. (Literally how many hammer blows on the pile per inch of additional advancement, 50-60 might be considered “refusal”.). Having said that, some reasonably conservative assumptions about the underlying soil need to be made to be defined the required “level of resistance”. Propped hammer sizing is critical, propped pile shoes (protective end treatment) and construction inspection is critical.
Contractors have been indicted for collusion with inspectors to “pass” piles. There was a huge case in NY some years back.
Whom did the owner hire to do construction inspection and did they have any experience in pile driving?
(Structural Engineer, I’ve worked in both design and construction.)
Suits San Francisco where the city government and most of the population believes that you can suspend nature’s immutable laws, such as the law of gravity or importance of marriage to the foundation to society, and build your world accordingly and nothing can go wrong because you’re doing the progressive thing, where reality is what you say it is and your delusions matter more than the disastrous outcomes from believing in fatal fantasies.
A sign of the general decline in standards.
Except for the location of overpopulated Guam, it was overliberaled SanFransicko.
I worked across the street when they were driving the piles for The Prudential Center in Boston (the fifties). The entire area is landfill.
My God,the noise,but the buildings are still there and doing quite well.
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Propped => proper ...sorry.
You think that’s loud, they use to use steam driven pile hammers back in the day. They are hydraulic these days.
I hope that someone sues these scum-sucking sociopaths.
If I recall correctly from a previous article about this, one issue in this case is that after the building was built there was excavation in an adjacent lot.
It was loud enough for me. :-)
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Not in Needham MA: https://www.google.com/maps/place/Needham,+MA/@42.3033149,-71.2180111,18z (click on satellite view)
If it was a deep excavation I can’t imagine it was done without “tying back” the sides. A slurry wall, injection grouting and alike. No way it was so deep as to undermine 60-90 foot piles.
Honestly, I really don’t think there would be speculation at this late date if the design was flawed. I, you, anybody could walk into the building department and request access to the plans. It would be clear rather quickly if the design was seriously flawed.
So...next we ask, was what was designed actually installed and properly inspected. This is a private building, it was the owner perogative to hire and pay for the inspection services they deemed necessary. The original design firm may well have no involvement in the construction inspection, if fact, it’s common for design firms to be undercut ($) by construction inspection firms.
You can’t get a 90 foot H-pile delivered to downtown San Franciso and welding H-Piles end to end is hugely expensive in both welding labor and productivity cost.
Did the contractor pay an inspection to say a 17 foot piece of scrap
Driven in 5 minutes is actually a 90 footer?
Where the inspectors even watching and keeping the appropriate records?
Sounds like the foundation wasn’t set on bedrock. Or maybe somebody cheated on the concrete. Either way I’ll bet the contractor is long gone and the bureaucrats who signed off on the work are retired.
I heard one of the construction workers on the radio this morning saying that they saw problems in the underground parking lot years ago. Big cracks in the walls. He stated that the talk among workers was the building needs to come down.
A 58-story building looks like a massive, monolithic structure, but it's generally built of steel beams and concrete columns and floor slabs (and maybe concrete beams, too). If you were to measure the volume of the building materials used to construct it, you'd find that this volume is dwarfed by the amount of open space inside the building.
A smaller building might topple sideways, especially if it is made of homogenous materials (like poured concrete or concrete blocks) instead of a composite steel/concrete construction. But tall buildings can't be constructed that way because the weight of the upper floors would require huge slabs and columns in the lower floors that would eliminate most of the usable space. When a tall building collapses, you have to keep in mind that every single element of the building is under a vertical force (gravity) that is enormous compared to: (1) any force that would move it sideways very far, and (2) the strength of the joints and structural elements that hold the pieces of the building together.
If you look at the 9/11 clips and see how those buildings collapsed, you'll notice that the first one to fall actually leaned in one direction at the top because the structure failed unevenly. But the downward force of gravity quickly took over, and propelled even the leaning section of the building straight down.
(I hope your not headed toward some truther end.)
The World Trade Center was a fairly unique design, meant to optimize open floor space, much of the weight was carried buy to exterior walls.
This building and 97% of all steel building are braced frames. The World Trade Center was not a braced frame in any classic sense.
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