It's those darned Mason architects....."It's opens doors, I'm telling you."
Posted on 10/24/2016 1:32:26 PM PDT by LRoggy
I worked at several sites along the TransBay Corridor redevelopment, within stone’s throw of this tower. You are correct about the tiebacks, shoring and bracing of the excavations. If they were done improperly, other buildings around would be in distress, and the monitoring equipment in the excavation itself would show lateral displacement. Driven piles into the overburden are ridiculous for a load of that magnitude. They needed drilled shafts well into the Franciscan formation.
TALL TREE LIABILITY
Your neighbor has a tall tree uprooting your driveway. You cut the roots on your property to halt the uprooting. The tree now falls on your neighbor’s car or house.
Who is liable??
“five-floor underground garage, where Porsches and Lamborghinis sit near walls bearing floor-to-ceiling cracks, many bracketed by stress gauges to measure growth.”
What will one of those Lambos be worth when it’s compressed to 0.001 millimeters?
I agree.
I can’t speak for the local conditions, I was just making observations. I’d imagine you can’t possibly drill a shaft without slurry. For the novices, slurry is a soupy clay liquid holding the sides up in a drill hole, preventing them from caving in. Concrete is heavy than slurry, pump the concrete in at the bottom of a drilled shaft, the slurry floats on top of the concrete, the hole is filled with concrete as you collect the over flowing slurry -possibly reuse it.
Different places lend themselves better to different techniques, bed rock in Mangatten is very-very shallow. Chicago is known for drilled caissons, bed rock at 60-90 feet. Bed rock in Lousiana delta might be 1,000 feet, not friendly to skyscrapers.
In this case, I would guess, the owner gave a clear message to the construction inspection staff not to increase costs. Fighting with the contractor, they might claim those costs or stick it elsewhere in a change order.
The only inspection was what the owner consider “due diligence” and they were preoccupied with selling two bedroom condo’s at $2.1 million.
Buyer beware!
“When radio and TV towers are erected they must own all the land around it so if they fall they don’t fall off the site”
I guess towers have end-to-end strength which buildings don’t and in some cases uneven or broken guy wires would exert lateral force?
Fat fingers on a phone...god lord.
=> Manhattan.
You're right about the unique design of the WTC buildings, but that doesn't change the physics of gravity. Remember that a building is designed to handle predictable loads -- the mass of the building and its contents exerting downward forces, and wind loads and seismic activity exerting lateral forces that are typically very small compared to the dead load (building and contents) and live load (people and processes in the building) of the structure. Once the configuration of the building or its structural elements changes substantially (by leaning, for example), all bets are off and it will no longer behave the way it was originally designed.
P.S. — Keep in mind that a toppling building would be subject to rotational forces that it would never experience in its “natural” state. Imagine a 600-foot building toppling sideways. In order for it to maintain its shape, the entire building has to rotate at the same angular (rotational) rate of speed. This means that the bottom of the building is basically turning in place while the top is rotating at a ridiculous rate of speed just to “keep up” with the bottom. A skyscraper could never hold its form under those stresses.
I’m a civil engineer (structural), licensed in New York. Worked on the World Trade Center before (kinda trivial but the work we do) and after 9/11.
I would agree, the leaning of the building does indeed introduce a “secondary moment” as such, now just 6 inches at the top it’s probably still neglegable, but concerning.
I use to do a lot of work on steel transmission towers, hand analysis and computer analysis. Until that building approached about a 9 degree tilt, the secondary moment is arguably neglegable. NOBOBY will in that building when it’s tilting 9 degrees.
You might enjoy this link ... though it's probably trivial to you if you're a structural guy. LOL.
Simulated Structural Collapses
What's interesting about this is that these stacked block structures would tend to be more likely to retain their shape while collapsing than a typical building would -- since they all see to be constructed uniformly without any consideration for open space in the interior. And yet they all seem to have minimal tendencies to topple, as opposed to collapsing downward.
The segment that starts around the 4:00 mark is a good example, because it looks like the whole right side is going to maintain its form and topple straight to the right. But it fails to maintain its form, in a manner consistent with all the other similar scenarios in the video: the bottom of the structure separates from the top because the top can't maintain the same rotational speed.
Fascinating!
This is nonsense.
Arguably, give me the choice, the safest building for any potentiality is a reinforced concrete building. But, it does not lend itself to high rise construction (generally) or renovation.
I can upgrade a steel building easily, welding more steel, not so much with a reinforced concrete building.
Of course. Isn't that why nuclear reactors are built that way?
2-inch tilt at the base and 6” at the top with more to come. I would move.
My 2 story wood frame apartment building went thru the Northridge earthquake in the San Fernando valley about 25 miles from downtown Los Angeles. The buildings half a block away collapsed.
My floor leans about 1.5” towards those buildings in the west. I have to prop up the furniture on that side. The other side leans leans a bit to the North and the balcony in the courtyard has cracks in the cement that are repaired from time to time.
60 Minutes ran a story about this last year.
Mt Ex B-I-L was in Commercial Real Estate way back when.
He always said The Bank of America Building in S.F. was the best Office Building ever constructed.
It also starred in the first Dirty Harry Movie.
It's those darned Mason architects....."It's opens doors, I'm telling you."
>>>Trump owned building at 555 California St San Francisco, formerly Bank of America building
And star of “The Towering Inferno” movie.<<<
Nope, star of the first Dirty Harry Movie. The Towering Inferno Building was a piece of Cinematic trickery.
You operate in San Fran, regardless of what you believe you donate to Dems or you aren’t in business long
Then, one day soon, following either an earthquake, or even under normal circumstances the building will collapse and EVERYONE in San Fran will say "how could that have happened?"
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