Miami Beach, Champlain Towers South apartment building collapse, Part 08 20

[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

SF Charlie
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[gonefishing2]

I think Elevator Machine room is on roof of original permitted 12 story Condo building.......

 

[Murph 9000]

The CCTV video from 87 Park clearly shows the 9.1 row falling well ahead of the 4 row. If you watch it slowly, the penthouse corridor can be clearly seen as a sharp line that has not significantly descended at the elevator end (where the large HVAC was), while the 9.1 row has dropped about 4 or 5 stories down. There is just no way that HVAC unit fell early and somehow the corridor attached to the same columns was still substantially in place between the HVAC unit and the rapid collapse. Additionally, in the early stages of collapse, the M line of columns appears to be leading the collapse of that section, at the sharp point of the shallow V-shape; which again puts too much structure between the visible start of the collapse and the large HVAC.

 

[Demented]

We don't know what was happening inside really. But, strangely underneath that red beam that to my tired eyes looks like the temporary support beam for a was a complete concrete beam replacement that went uninspected and approved. The unit appears to have been fully supported on columns, but why are there solid modifications to a temporary structure that has zero function and was engineered to be as light and easy as possible to support a much smaller unit? That's just bugging me is all.
If those additional beams were installed under to stiffen the support structure and were resting on the roof surface, that would be interesting. Having trouble finding permits for this.

A possibility is the building began to collapse on the interior before making it's way to the deck.

 

[arbitraria]

Though there are explosives within airbags, the plaza collapse air boom would hardly register, wouldn't even crack the windshield.

That CRV looks like it took a decent hit from something.

 

[Demented]

Precision guess work based on information provided by those of questionable knowledge

 

[Optical98]

I can't remember where I pulled this close up view of the roof from -

 

[gonefishing2]

That close up definitely looks like a concrete beam

 

[Demented]

https://www.youtube.com/watch?v=NhAkMdbSRXc

At time. 4k non potato

https://youtu.be/NhAkMdbSRXc?t=270

Poured before inspection eh.

 

[AutisticBez]

The columns that fail first just happen to be at the bottom of the ramp. They line up perfectly with a car collision. Ignore the eyewitness accounts. The timing is unknown. Car hits column. Enough said. Prove it wasn't a car that destroyed the M11.1 column.

 

[Murph 9000]

A possibility is the building began to collapse on the interior before making it's way to the deck.

That seems extremely unlikely, well into magic bullet territory, if you're trying to suggest the HVAC caused or contributed to structural failure vertically, all the way to basement / lobby level, before causing the pool deck to drop. The Nir family from 111 had to walk past E4 and H4 to get to the lobby (those columns are part of the north wall of the corridor. There's a little grey around the precise location of the son and daughter when the mother ran to them after seeing the surface parking collapse from the lobby, but it appears that they were at least as far back as E4 if they were not back at their unit. They really could not have missed a major failure involving H4 prior to the surface parking dropping.

The lady from 611 had to run past H4 while making her escape. Admittedly, she was running with the building literally crumbling behind her, so would easily miss things due to adrenalin-fuelled tunnel vision. The certainty, however, is that her living room (with no direct proximity to H4) was cracking, but the slab directly attached to H4 was there for her escape. Even in adrenalin survival mode, she probably would have noticed a major structural failure with H4 as she passed it.

H2 would be more hidden from the witnesses, but the hypothetical progression towards the pool deck from it couldn't be missed by them.

H4 was part of the wall of the penthouse corridor, clearly visible after 10 and 11 stacks had significantly descended. We see essentially the entire 4 line of columns above and behind the collapse of the south facing units. With less precise identification (dark blob on the video without clear features), we see structure behind the 4 line as it begins to fall, and there's only the 1 and 2 lines of columns remaining to provide that.

If H2 and/or H4 failed prior to the pool deck, it would require far more than a crack and dropping an inch or two to propagate that failure across to M9.1. The internal failure would also need to pause for several minutes after progressing to the pool deck before the tower came down.

There is substantial evidence that there was no early failure involving the HVAC, with really nothing significant to support the alternative hypothesis. Its position on the rubble is entirely consistent with mostly just riding the collapse downwards and taking a tumble either due to torque acting on it from the support beams failing at one end (hinging at the other), meeting some resistance on the way down, or just rolling as it came to rest on the pile.

 

[hpaircraft]

Prove it wasn't a car that destroyed the M11.1 column.

https://en.m.wikipedia.org/wiki/Burden_of_proof_(philosophy)#Proving_a_negative

 

[nessman]

HVAC units are a non-issue here. I don't know why people keep bringing them up.

If it was a car that took out a column, they've would have pulled out a car from the rubble with significant front-end damage consistent with that of a car hitting a tree. So far nothing like that has happened.

The Building Integrity YouTube channel videos have provided the most professional insight and plausible theories as to what happened - and he explains it in a manner that is easy for the average layman to understand. The guy in the videos is the president of this company.

https://consultengineering.com/

 

[Demented]

@Murph9000
Not trying to suggest that at all.
Just trying to figure out how and why a temporary support fixture got turned into a permanent load bearing device, on top of a repaired/replaced concrete column that was poured before inspection, appears to have no reinforcement, and was still given the OK by the inspector on site and city. If that concrete beam was cracked and failed, that would put the temporary support structure as the only thing spanning that gap. I'm more concerned of the forces that would be on the columns and shear wall in that instance.
I don't see any rebar on that beam that was replaced. We do have absolute 100% proof that beam was a temporary support structure to avoid shoring, and the concrete beam was poured without inspection, on an over 90*F day, and passed. That's an issue. If that's not an issue, then none of the shoddy labor is an issue. Why are we concerning ourselves with missing rebar and bad concrete repairs from this same crew in lower portions, but on the roof it's now stupid because it involves an HVAC unit? FFS.

Angela Gonzalez and Devin Gonzalez did fall from the 9th floor to the 4th floor though internally. They were pulled alive. They heard noises around them and began to run. Made it to the front door, made it 5 feet or so, and then landed on the 8th floor. and then subsequently down to the 4th floor.


Anyone know which permit was for the HVAC replacement where the crane was on 88th 10AM 1/23/2019?

 

[Demented]

Yeah nevermind, no permit.

 

[CE3527]

Seems the only consistent thing on the building over 40 years is ignoring codes, permit requirements, and best practices for maintenance.

 

[Demented]

What were these two trunnion-like fixtures (one open, one closed) atop the columns used for?

At 1:26 in

https://www.youtube.com/watch?v=ElMjRSgMsiM&t=...

I did a cursory look through the plans, but didn't see anything like that.

https://www.townofsurfsidefl.gov/docs/default-sour...

I'm sorry but this area is just very intriguing. Could they have ran a roof anchor into this beam? Seems they didn't care to actually move HVAC units to put them in the right spot.
So many new and odd variables. I don't understand how anyone can do proper maths or run simulations without proper data. There's so much different here than what was in the original drawing. We also have the elevator in use at the time, pulling a heavy load up from the roof.

Think outside the pointy circle.

 

[waross]

I doubt many folks on this forum, have actually worked with yokum and hot lead, to seal the hubs of cast iron sanitary sewer piping.

Yokum[/b]]The family name of some Al Capp cartoon characters;
Li'l Abner Yokum
Daisy Mar Yokum
Mammy Yokum

Oakum is a preparation of tarred fibre used to seal gaps. Its main traditional applications were in shipbuilding, for caulking or packing the joints of timbers in wooden vessels and the deck planking of iron and steel ships; in plumbing, for sealing joints in cast iron pipe;

Pouring lead to backup the oakum seal.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[gonefishing2]

LOL….. At least I got the ‘kum’ part right!

 

[Murph 9000]

@Demented

Ahh, ok. I was taking your repost of warrenslo's roof-first / HVAC-first theory as context for the subsequent message. As evidence of general shoddy workmanship and poor permitting practices and compliance, sure, it's quite reasonable to examine all of the work.

The Gonzalez family were in 904? Their front door was basically right on the ragged cut line between the surviving section and collapse zone. The corridor outside that would have been relatively late in the rapid collapse of the middle, but heavily damaged on all levels. Their front door was directly adjacent to E4 on the E4–H4 span, most of which was gone, leaving a thin strip of damaged slab on the east side of the E line. Some slabs looked like they were sagging down there, after the collapse, possibly partially or fully detached from E2 and/or E4.

I'm not certain from what I've read of their survival, but I think they fell during the main tower collapse, trying to make it out the door. Pure luck or fate put them right on the survival line at that moment. The brief half second or so pause in the collapse at the 4 line may have aided their escape. That's my interpretation of how they both fell and survived, and I think they effectively fell one floor at a time, "cushioned" on the growing debris below the slab they were on, until they landed on the 4th floor corridor slab (probably sticking out a little further than slabs above, or their slab or surrounding materials tipped/pushed them onto it. Alternatively, they may have fallen immediately post-collapse, in the dark and dust, taking the wrong step as they tried to get from their survival ledge across to the corridor for the elevators and stairwell. Equally miraculous and horrific, either way.

 

[Demented]

I believe it was floor after floor with each one cushioning it, and the 4th floor was the top of the pile by the time it stopped. They've described very little but they did mention pauses between falling each floor initially. They were rescued from the top of the rubble pile nearest the non-collapsed section. (NW side), shortly after first responders arrived. You can hear the coordination of their rescue on the released Miami-Dade fire radio. There was another survivor who reported hallway floors gone, as well as fire rescue reporting portions of interior floors collapsed in the still standing section. As to where, I have no clue. I'm sure they reported that all in debrief. There were known cavities in this area with survivors they were talking to, and banging/cries for help they heard. Part of their whole panic with the storm, the fires, the flooding, and the building being unstable. Survivors were stuck around there.

Edit: Yes, the Gonzalez was in 904.

“In the middle of the night, my daughter woke up because she heard a strange noise, and when she woke up, the building was shaking,” said Angela Gonzalez's mother, Kathleen Gonzalez.

“She started screaming for them to get up and get out, and she just ran with her daughter, pulled her daughter by her arm, when they got out the front door, they didn't even go five feet, and it fell down to one floor below,” she said.
Angela Gonzalez and Deven were separated, and as Deven screamed for her mother, Angela Gonzalez “crawled over and put her body on top of my granddaughter and they fell again all the way down to the third floor,” Kathleen Gonzalez said.

They got very lucky.