Miami Beach, Champlain Towers South apartment building collapse, Part 17 14

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04
Miami Beach, Champlain Towers South apartment building collapse, Part 05
Miami Beach, Champlain Towers South apartment building collapse, Part 06
Miami Beach, Champlain Towers South apartment building collapse, Part 07
Miami Beach, Champlain Towers South apartment building collapse, Part 08
Miami Beach, Champlain Towers South apartment building collapse, Part 09
Miami Beach, Champlain Towers South apartment building collapse, Part 10
Miami Beach, Champlain Towers South apartment building collapse, Part 11
Miami Beach, Champlain Towers South apartment building collapse, Part 12
Miami Beach, Champlain Towers South apartment building collapse, Part 13
Miami Beach, Champlain Towers South apartment building collapse, Part 14
Miami Beach, Champlain Towers South apartment building collapse, Part 15
Miami Beach, Champlain Towers South apartment building collapse, Part 16


SF Charlie
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[Sym P. le]

A refinement to my trapezoidal failure theory earlier in this thread (26 May 22 07:20):

The concrete block infill along the building perimeter will not allow the slab to slope in that region, thus, at the perimeter, the slab can only slope beneath the less rigid glazed sections. The effect on the view from the Ring cam is that the credenza will sit level while the farther regions are free to slope, which could explain why the cam is not in plane with the kitchen counter top, even in the first frame.

A further implication is evident in the collapse sequence from the Park tower. At Column line M the failure is distinctly different on either side of the column with the west side dropping precipitously while the east side merely droops, at least initially. If the slab steps (from the pool deck to the interior slab) are considered as lintel beams, there is minor additional support from line K-L and L-M, a 7" step, while on either side of these, the step is 1'-6" offering much greater support.

If Column L buckles first and M is still stable, the thin lintel and block infill could create a condition where the slab suddenly shears off the west side of Column M leaving the column to continue supporting the structure to the east, if not only for a few moments. In the collapse video, it appears that Column K fails in near tandem with column L but Column M is delayed.

Profile showing column locations and CMU infill (darker) and perimeter step/lintel support (red/orange)

CMU infill causes perimeter slope to be stepped in the event of column failure (red line example)

 

[Sym P. le]

It seems you've answered your own question. My own opinion is that between the momentum of the collapse and prevailing atmospheric conditions, a dense cloud of dust was pushed around that corner of the building. In the photo I posted earlier, it appears that there is a thick coating of dust on everything adjacent to and south of the corner but quickly thins out towards the pool. Just one of those things that has no other explanation.

 

[Nukeman948]

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:

As any chef could tell you, breading will not stick to dry chicken. You must first wet the chicken, preferably with an egg wash and provide proper seasoning.

Concrete dust will not stick to a vertical surface unless it is wet or sticky. The railings on the balconies are covered with dust in the same way too and yet there isn't all that much dust on the cars.
When dew begins to form it does not form everywhere all at once. It starts to form on cooler surfaces first. If the previous day was mostly cloudy but the sun came out after the building shadow covered that part of the wall it may be one possible explanation. It is also possible that someone had been watering the plants or kids had a water balloon fight there. I really don't know and I really don't care. But it seems obvious that that column was wet as were the railings.
Edit: I believe there was a drinking fountain in that corner too and if the water line that fed it, or any other water line in the area, was run along the wall it may have survived the initial collapse long enough to spritz that area.

Perhaps you could give us your explanation of why the dust stuck to that column and why you seem to think the explanation for it is so important.

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[FJBnomics]

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:

IanCA, Thank you for posting pictures I have not seen, which appear to be from NY Times. I read the NY Post, not a NY Times reader, so I had not seen these images.

Ok, I will take the bait, in hopes of getting confirmation of what you are leading too. Structural Slab with the chemically changed concrete that is now a gypsum powder form, most likely had water trapped between structural slab and finished tile floor, thus the powder picked up moisture as the structural slab failed just below that area of the column or any number of reasons.

Either way, it appears the first concrete failure, and the noise heard by witness of small collapse before deck failed, could have been that small portion of the slab that fell on the EAST side of the block wall around the pool exhaust fan.

If that small section fell first, then that could be the 'specific' opening that serves as the Southern Focused initial VENT of powdered concrete, thus explaining the heavy concentration of Powder mostly on North FACE of Block privacy wall column and evenly coated from bottom of block pilaster to top of pilaster......

Edit: Of course a slab drop South of K11.1 ( Column under Planters) where deck sagged 2 weeks before collapse), could be a direct result of the slab detaching from South Wall and retracting just a bit, in area of "Focused' Dust Blast at South wall pilaster, but not falling 2 weeks earlier. So once Parking Deck/Patio Deck Collapsed, there was already a specific opening to vent the powdered mix at that pilaster. Slab drop does line up N to S with this area of South Wall.

IanCA, Feed Back Requested Please!

 

[FJBnomics]

A refinement to my trapezoidal failure theory earlier in this thread (26 May 22 07:20):

Sym P. le what I notice in your GIF when holding my mouse on lower floors vs upper floors is that the top 2 to 3 floors drop a greater distance in same period of time as the lower say 10-11 floors do.

Clearly if you adding some floor lines to your GIF, I believe it would show this accelerated rate of drop on upper 2 or so floors vs rest of floors below.

I think I see the slight lag of M column line as it tears away from Easter portion of building.

 

[Sym P. le]

Perhaps because the drop between the two frames is one and a half floors it gets confusing as to what is being seen. I think I see what you're looking at but when I look closer it just seems illusory.

 

[FJBnomics]

Perhaps because the drop between the two frames is one and a half floors it gets confusing as to what is being seen. I think I see what you're looking at but when I look closer it just seems illusory.

Illusory or Science? From my memory the 13th Floor Penthouse was very open floor plan with long slab spans, and I believe the 12th floor Penthouse was similar as compared to the 11 floors below. So less Block In-Fill Walls, and longer spans between columns.

Thus, are we seeing the top too slabs hinge back (North) a greater distance, in same time period, due to Trigonometry of the longer un-supported slab spans from outer column line to the next column line North?

 

[SFCharlie]

Great work!
I had to add the basement and pool to help me make sense of it all...

SF Charlie
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[SFCharlie]

what I notice in your GIF when holding my mouse on lower floors vs upper floors is that the top 2 to 3 floors drop a greater distance in same period of time as the lower say 10-11 floors do.

Please don't get ahead of the video, so many frames passed in between the two hi-res frames we have!
(I have removed the repeated frames of the twitter i{hone vid.)

 

[FJBnomics]

I can see the parapet wall at the 12th story roof line, appears to roll backwards (North) a lot more than the 13th floor roof parapet, along KLM stack, while the Column line between K and L for the 12th and 13th floor, buckles outward at the 12th floor roof line

 

[SFCharlie]

I updated the gif above, Here is the new powerPointy

SF Charlie
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[dik]

We're in the wrong business...

https://www.sun-sentinel.com/local/...0220613-mcmb3j6babainewrauf2l36q3q-story.html

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

 

[FJBnomics]

I found the floating house video at Yellowstone on the Sun-Sentinel link, very interesting.

 

[Jeff Ostroff]

I just uploaded my video tonight analyzing the $100 million lawyers fees filing, it was 400 pages. But in reading through it for the video, I found this interesting tidbit about one of the plaintiff lawyers:

SMB Took the Lead Questioning Role at Depositions to Secure the Devastating Admissions Which Compelled Settlement
28. Construction cases are often won and lost in depositions. Depositions were taken of seven individuals associated with the design and construction of 87 Park. Mr. Goodman was the lead questioner on five of these depositions and assisted Ms. Bucciero in preparing for the other two depositions, which she took. The depositions taken by the team of Mr. Goodman and Ms. Bucciero, with tremendous assistance in preparation from Mr. Dordick were essential to this resolution.

29. Hundreds of hours were dedicated to preparing for and taking these depositions, and it proved to be of tremendous worth to this case.

Mr. Goodman's effective questioning elicited admissions that were utterly devastating to the 87 Park defendants. This included
(1) the deposition of Garfield Wrey, the lead geotechnical engineer on the project whose testimony buried the other 87 Park defendants for not following his warnings;
(2) the deposition of NV5 senior executive Eric Stern who utterly broke down at his deposition and admitted fault on behalf of NV5; and
(3) the deposition of Kerry Lopez, the author of the "F**k That Wall" daily report whose testimony all but guaranteed punitive damage finding against the general contractor, John Moriarty & Associates of Florida, Inc.

 

[MaudSTL]

I would love to read those depositions.

 

[zebraso]

Lead geotechnical engineer ignored. How many other engineers were ignored in the construction of Park?

 

[IanCA]

Structural Slab with the chemically changed concrete that is now a gypsum powder form

I certainly think the structural concrete of the parking deck adjacent to the southern property line wall had experienced the most degradation and when it collapsed it also created far more dust than concrete it good condition would.

most likely had water trapped between the structural slab and finished tile floor, thus the powder picked up moisture as the structural slab failed

I think it is highly likely that the concrete in that area was more porous as a result of the degradation and retained moisture more than usual, but that it cycled with the weather and irrigation runoff. I also think the dust was dry enough at the time of collapse to be freely released into the air.

Perhaps you could give us your explanation of why the dust stuck to that column and why you seem to think the explanation for it is so important.

I appreciate you asking.
I agree that the columns were all relatively damp but I believe that the difference in dust level was due to the difference in proximity to the source of the dust rather than any significant difference between moisture levels. This is important because I believe it indicates the extent of the concrete degradation at the southern property line wall and is a further illustration of the sequence of the collapse of the deck. If the parking deck collapses first at the southern property line wall creating a large volume of dust and the remainder of the deck then collapses, the initial dust would be rapidly forced up through the gap below that column, making it very likely the column would receive a thick and even coating of dust. If the deck collapses first at column K13.1 (74) then the dust will be forced more equally north and south within the garage and should be visible in the video by Adriana Casillero.

If that small section fell first, then that could be the 'specific' opening that serves as the Southern Focused initial VENT of powdered concrete, thus explaining the heavy concentration of Powder mostly on North FACE of Block privacy wall column and evenly coated from bottom of block pilaster to top of pilaster......

Essentially yes, but I believe it was the section of deck to the west of the column that failed first.

EDIT:

Just one of those things that has no other explanation.

Please consider the explanation above.

Thanks for your work on the drawings.

 

[Nukeman948]

I agree that the columns were all relatively damp...

No. You know that is the complete opposite of what I've been saying.
The reason the dust stuck to only one column is because only one column was wet. After the dust hit that column, all the dust that didn't stick to that column would be dispersed in a dust cloud all around the area. If all the columns were wet we would see a gradient of dust quantities on the columns leading us back to the source of the dust. I also believe that dew is the reason dust stuck to the vertical parts of the balcony railings (something you are avoiding talking about) and very little on the cars that were right next to the wet dusty column.
But none of the dust patterns I see indicate a larger quantity of dust coming from that one location.

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[IanCA]

No. You know that is the complete opposite of what I've been saying.

Sorry, I didn't intend to misrepresent your position.

If all the columns were wet we would see a gradient of dust quantities on the columns leading us back to the source of the dust.

I agree, and I do see a gradient of dust on the wall. Do you see that? I should have credited Joe Raedle. The original image is here: link.

dust stuck to the vertical parts of the balcony railings (something you are avoiding talking about) and very little on the cars that were right next to the wet dusty column.

I didn't address the railings because I hadn't studied the railings and I wasn't sure if you had a particular image in mind. I think your observations agree with the point I'm trying to make. I am asserting that the dust was blown upwards and the balconies are above the deck, only heavier particles would fall back onto the cars.

 

[SFCharlie]

I hope the latest gif will shed some light on the timing of the huge spurt of dust sent into the air at the southwest corner of the pool deck.
By this time, I suspect that a lot of debris from the collapse had accumulated in the basement and that the collapsing tower blew this dry dust out forcefully?

SF Charlie
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