Posted on 10/24/2016 9:12:04 AM PDT by Ray76
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.
(Excerpt) Read more at hosted.ap.org ...
Really great album, “Winter Dreams” is a surprisingly great song considering Udo’s “interesting” vocal style.
“What would happen in a major earthquake?”
Cracking noises, followed by gravitationally motivated downwardness.
The 880 freeway section which collapsed in the 1989 quake was later revealed to have been constructed on reclaimed compacted loamy sand-—with little or no anchoring in bedrock. Also, the steel rebars inside the concrete were too far apart, in violation of engineering load specifications.
I suspect this building’s problems may be due to similar causes.
Foundations which stay wet will settle; I suspect the homeless peeing on the foundation wall at the sidewalk intersection caused it.
Did I miss something?
https://www.linkedin.com/in/pamela-buttery-3568b97b
Will their errors & omissions (E&O)insurance cover this?
How ironic that nearly the entire city of SF ridicules a master high-rise builder running for president, and they can’t even put a foundation in right.
Recall Chicago’s John Hancock Building!
In the summer of 1966, a 12-ton column was placed on the base plate at the top of one caisson, and the plate tipped slightly. A foreman wisely ordered the column lifted....
Six months later, at an estimated cost of $1 million, the caissons had been thoroughly inspected and repaired. A large void had been discovered in two concrete caissons, and earth, sand and other foreign material in three others.
What was the cause? ``Careless pouring of concrete (and) inadequate or missing caisson liners,
http://articles.chicagotribune.com/1985-03-24/features/8501160598_1_caissons-john-hancock-center-architectural-history
A friend was involved on this project.
They had to jack out the concrete on a bunch of the caissons $$$.
Built on landfill, most likely. Or upon remains of the great earthquake.
Not to be morbid, but that thing is coming down when the next big one hits.
There is often E&O insurance but it won’t come into play without a lot of litigation and possibly a proof of insurable loss. In this case the design team has maintained they made no error. The used deep foundations with side friction bearing and designed for some differential settlement.
All buildings not on deep thickness bed rock settle due to the “dead load” of the structure. Subsidence is acceptable if it is designed for and happens in a uniform manner. The designers are maintaining that initially all was within limits and later a de-watering effort of the nearby construction disturbed their building’s bearing due to the water coming out of the deeper material causing it to subside. This is a real concern and it causes some urban designs to incorporate a deep concrete slurry cut-off wall around the perimeter, of the second building — another hellish cost item.
In the case of the Hancock Tower, this is why for the last forty years drilled deep caisson foundations have generally been supervised/monitored during installation in a continuous process as the contractor has drilled them. As waste material comes up, as the bottom and sides are inspected prior to concrete placement the observing engineer confirms what the designer planned on encountering. Deep foundations have often placed a “test pile” or test unit where load is imposed and subsidence measured. If the subsidence curve isn’t hyperbolic showing decreasing subsidence the design must be altered to account for it.
There have often been storage silo’s in river bottom areas that when loaded with material they were built to store, subside in an uneven manner and have to be abandoned and removed.
I will say that Forensic Investigation is a fascinating field. Having spent about 45 years managing various aspects of construction I have had the chance to provide expert testimony, participate in investigative teams, law school mock trials, and similar items. I have seen some astonishing events and incidents that initially baffled me. Early on in my career I spent three years with a manufacturer of building components settling claims after investigating them.
I was fortunate to get to attend some seminars given by the forensic teams involved in the Twin Tower disaster and it was truly great to see that poster Two-Thirds Vote Aye and my armchair analysis of much of the collapse and clean up occurred as we theorized at the time of the events.
see above ol’ timer if you are still around
Pamela Buttery noticed something peculiar six years ago while practicing golf putting
Did they allow women to start playing golf? Did I miss something?
_________________
Only at home.
kip = 1,000 pounds
1 ksi = 1,000psi
Purely imaginary movie per the seismic experts (e.g., there will not be a tsunami), but an awesome one nevertheless (hey, it's got The Rock in it!):
Lots of San Francisco buildings come down...
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