Miami Beach, Champlain Towers South apartment building collapse, Part 10 79

[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


SF Charlie
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[SFCharlie]

Are you saying ... is not the roof surface hinged down?

What I'm saying and I believe, is that I see the floor 13 penthouse roof parapet intact in frame 22 (the upper most red line), And when I back the red shape into the previous frame, and realign it at it's bottom, that I can make out the PH roof parapet all the way back to frame 7. It fits with the idea that the whole stack has dropped about one floor at the start of the video. I'm definitely not sure what I see above (odd black shape) or to the left of it.
[sub]I'm definitely sure I don't know what I see above (odd black shape) or to the left of it.[/sub]

 

[zebraso]

What I'm saying and I believe

Thanks. Trying to digest this stuff....

 

[Js5180]

Nukeman,

As blurry as the video is, I have no trouble seeing that the two flashes are two floors apart from each other, and are of a color and brightness inconsistent with any other light source except an electrical arc.

Regardless of what floor they were on, or whether they came from a unit panel or the corridor conduit, it’s clear that the upper part of the x10 area was collapsing, isn’t it?

And despite the video being blurry, it’s also easy to make out the white stucco band on the K column, and it doesn’t seem to have moved in the first 34 frames, despite the collapse being well underway.

While this isn’t directed at you in particular, there seems to be a selective characterization of the video as “too blurry” when we’re discussing a top-down collapse, but clear enough to show a basement-up collapse. I’m not suggesting a beer can rolled off the roof, broke the parapet, caved in the pool deck, dropped a piece of concrete on a gas pedal which ten minutes later crashed a car into a column and brought the building down.

But, a pool deck that was weak enough to collapse under its own weight is also a pool deck weak enough to collapse from ANY external force, and there certainly seem to be parts of the upper floors that were collapsing prior to any changes directly below them.

Finally, the early frames show an upper PH parapet east/right of the M column line, but NOTHING west/left of it. I have never heard an explanation for such a clean shear of this slab and it’s parapet along a column boundary. The theory is that the section between L and M “just dropped” 10 feet. Was it not attached in any way to the slab east of the M column line? No hinging, no nothing. It just sheared clean off on one side, while the other side stayed up? How?

 

[spsalso]

Js5180,

You're saying that, although the pool deck collapsed 7 minutes before the building fell, the building failed from the top, and took things below down?

I assume you think the pool deck failure DID cause the building to fail. So how did that cause the failure to start at the top?

If you think the pool deck failure DIDN'T cause the building to fall, I will note that there's a hell of a coincidence there.

spsalso

 

[spsalso]

The "flashes" that have been attributed to electrical arcing/shorts are certainly interesting.

I note that photos appear to show lengths of conduit sticking out of the (formerly) still standing building. There are NO wires sticking out of them. The implication is that the falling building pulled the conductors out of their circuit breakers. Thus those wires would not be energized and could not short and create arcing.



spsalso

 

[Js5180]

If the upper floors were collapsing, then I’d expect them to be shedding debris. The cantilevered balconies and roof only need to be slightly out of level before debris (including cinder blocks) starts falling off. I’m not saying an AC unit rolled off or anything like that. But if we’re saying that the pool deck could collapse under its own weight, than anything falling on it can’t be ruled out, can it?

What I’m seeing, before the eastern part collapses, is that in every single frame, there is more deformity in the top four floors than the lower ones.

The eastern part clearly collapsed a different way - bottom up - and the upper slabs were nearly intact in the debris pile.

 

[Reverse_Bias]

Pretty simple, that part of the wall tipped backwards onto the roof at the start of the collapse or just before the collapse when that section of the building was sagging.

We'd know a lot more if the CCTV footage started like 10 seconds earlier.

Finally, the early frames show an upper PH parapet east/right of the M column line, but NOTHING west/left of it. I have never heard an explanation for such a clean shear of this slab and it’s parapet along a column boundary. The theory is that the section between L and M “just dropped” 10 feet. Was it not attached in any way to the slab east of the M column line? No hinging, no nothing. It just sheared clean off on one side, while the other side stayed up? How?

 

[Spartan5]

If the upper floors were collapsing, then I’d expect them to be shedding debris. The cantilevered balconies and roof only need to be slightly out of level before debris (including cinder blocks) starts falling off. I’m not saying an AC unit rolled off or anything like that. But if we’re saying that the pool deck could collapse under its own weight, than anything falling on it can’t be ruled out, can it?

Show us what this failure looks like on the plan. Where do the balconies start to go out of level? How? Where do the cinder blocks come from?

The failure of the pool and how it could bring the building down have been modeled. I’ve seen no such animation or even a basic sketch for how this happens on the roof.

And then there are the obvious deficiencies in the pool deck slab that are evident in the unusual punching failures at each column. No imagination is needed to see that there was something significantly wrong there.

A cinder block fell off the roof. Or maybe it was a drone strike. Or perhaps an asteroid. Most likely is that some 300+ lb human committed suicide and they were the trigger for the pool deck failure. But that probably didn’t happen either. Right?

 

[Js5180]

Spsalso,

I can’t find a good image of the conduit. I’d agree if the wires pulled completely out there’d be no arcing from the conduit. I’d like to see a clear image of the conduit breaks. The best ones I have seen have it bending down, rather than shearing off.


Reverse bias,

That quote is mine, not spsalso’s. But we’re not just talking about a wall tipping back. We are talking about a slab in that area that has fallen, not hinged, at least 10 feet, while the slab on the other side of the M column is yet undisturbed. How does such a clean break occur at a column line? I’m thinking a construction joint could do it, but nobody has suggested that. Either way, we have a very distinctive loss of a specific section, from column K to M, at the PH roof level. If the L or M columns had magically disappeared from the basement, wouldn’t we see a “V” in the slabs up above? And not a clean break?

 

[Spartan5]

There is some shear puncture at the outside columns and the slab hinges down somewhat... maybe 20 or 30 degrees. Nobody is in PH-A at that hour to see it, but now a couple lose pieces (~15lbs) of the parapet or large crumbs of the slab where it broke fall and either hit the balcony immediately below of ricochet down and hit the pool deck, making "construction noises" that reverberate through the building. At some point, a large section of parapet (>15 feet) lets go, takes out the balcony railing below and falls 12 stories to the pool deck starting its failure.

That's kinda what I see as a remote-remote possibility. I'd love to hear how this couldn't ever-ever happen.

“ I'd love to hear how this couldn't ever-ever happen.” it’s not our job to prove a negative.

Show me on the plans where this 20-30° “hinge” forms. We’ll ignore how there are no reports of any noises from 12, 11, 10, etc.

Sketch out where this >15’ piece of parapet wall cleaves itself from the building. What’s that weight? What mechanism of failure are you proposing?

Oh… maybe it was some resident who was angry about the repairs who went up to the roof and threw the tar buggy off. But that’s too heavy you say. Well not until you consider that ratchet strap come-along they rigged to the steel beam and roof anchors to pull it up the ramp of cinder blocks, tar paper, and loose AC units.

That's kinda what I see as a remote-remote possibility. I'd love to hear how this couldn't ever-ever happen.

Look closely in my PowerPoint. If you stare at it with your eyes crossed you can make it 3D. IT’S ALL RIGHT THERE IN PLAIN SIGHT!!!

 

[Optical98]

SFCharlie

Can I get a new link to your security video project, the one I downloaded before has 22 frames, is there a new one with more frames? I do have power-point btw.

Thank you

Spartan, you have a power-point file too?

 

[Js5180]

Spartan,

Drone strike? Come on.

But again - if the pool slab was so weak to spontaneously collapse, then anything landing on it, driving on it, or looking at it could bring it down.

My sequence? I don’t know, actually, but I’m thinking there was cracking (or a construction joint) on the roof level that allowed the roof slab to separate at the M column line. Once we get there, the western half of the PH roof is wobbly. The parapet is poorly attached and as we saw in the controlled demo, prone to separating from its slab. A few cinder blocks hitting the pool deck at 70mph easily break it - especially since everybody seems to agree it could collapse entirely under its own weight. It needed no help.

But the pool deck collapse didn’t immediately bring the wall down. So then what? A column in the garage is gradually shedding concrete for seven minutes while it’s rebar bends? No different from the upper floors gradually giving out. EXCEPT - in the upper floors we have drywall and steel studs and whatever other wall finishing which contributes little strength but very likely acts as a brake.

 

[Spartan5]

That quote is mine, not spsalso’s. But we’re not just talking about a wall tipping back. We are talking about a slab in that area that has fallen, not hinged, at least 10 feet, while the slab on the other side of the M column is yet undisturbed. How does such a clean break occur at a column line? I’m thinking a construction joint could do it, but nobody has suggested that. Either way, we have a very distinctive loss of a specific section, from column K to M, at the PH roof level. If the L or M columns had magically disappeared from the basement, wouldn’t we see a “V” in the slabs up above? And not a clean break?

Just sketch on the plan where the spontaneous slab failure occurs. I want to see a sketch of what people think failed and their purported mechanisms. Not wild-eyed suppositions made by people begging others to prove that it couldn’t “ever-ever” happen.

No one on the floors immediately below notice this? Somehow the otherwise shittily constructed and maintained building withstands this insult? Didn’t you see the real estate pictures showing the massive defections and distress from the tile loads?

And all of this based on a video of a video; both of which have been smooshed more than a Vegas escort. (But we’re gonna try to fix it with PowerPoint.)

EDIT: forgot to add that said video didn’t start until after the collapse did.

 

[Js5180]

Spartan,

You say, “Sketch out where this >15’ piece of parapet wall cleaves itself from the building. What’s that weight? What mechanism of failure are you proposing?”

Watch the controlled demo video. The parapet over unit 1205-ish clearly “cleaves itself from the building.”

https://m.youtube.com/watch?v=5ZDZ9nN5kns

EDIT: the parapet cleaves itself at 0:11.

 

[Js5180]

It isn’t “wild-eyed” to see that in the video, the upper PH roof slab left/west of the M is missing, and the right/east section is not.

You can pull out your thesaurus and throw a few more adjectives around, but I see blue sky, beginning just left of the M column line. That’s a clean break. What’s your explanation for this?

 

[Spartan5]

Roof vs pool deck: were major structural defects identified and repairs required for both or just one of them?

As for “spontaneous failure” of the pool deck. It is a possibility. But I don’t think any has said conclusively that that was the case.

Sure, any number of things all more or less equally likely could have fallen from above and triggered the patio failure:
*space debris
*meteorite
*heavy suicide carcass
*cinderblocks, tar paper, and AC units
*drone missile (or just a large drone… I think I saw one with red paint on it)
*UAV
*malicious wheeling of tar buggy off the top
*Failed group BASE jump attempt from poorly installed roof anchor… well just the test anyway… with a green hoist sling full of those tar rolls
*(reserved for suggestions)

If only we had the whole videos. We could see if it was any of that. All are remote possibilities though. Right?

 

[Js5180]

I’m sorry. This is absurd. They were working on the roof that day, and you’re saying a drone strike, meteor strike, or base jumper is more or less equally likely to have happened, compared to something falling from the roof?

 

[Spartan5]

It isn’t “wild-eyed” to see that in the video, the upper PH roof slab left/west of the M is missing, and the right/east section is not.

Shocked that none of the major news outlets or other experts are reporting on this. We need to get them that PowerPoint, STAT! Or maybe they are part of the Surfside coverup. It’s certainly a remote possibility.

I’d just like to see these “theories” of how this failure occurred sketched on the plans is all. With some postulation as to their supposed mechanisms.

That aside, the poor video of a poor video is inconclusive. We know that the patio collapsed several minutes before the rest of the building. That’s it. Aside from these wild-eyed interpretations of the video (which seems to be a local affliction) there’s no evidence for that.

 

[Js5180]

I haven’t heard the news report on ANY theories. I feel like that’s why most of us are still here.

EDIT: For the record, many of us here are laypersons as far as structural engineering goes. We respect your professions. But when you flip to calling everything “wild-eyed” and talking about drone/meteor/suicide strikes, the only takeaway is that maybe y’all have some blinders on. After all, we weren’t the ones that stamped these plans. So, some of us are here maybe because we feel we have a different viewpoint that could, remotely, incrementally, advance construction safety.

 

[Spartan5]

I’m sorry. This is absurd. They were working on the roof that day, and you’re saying a drone strike, meteor strike, or base jumper is more or less equally likely to have happened, compared to something falling from the roof?

Yes. They worked on the roof that day. And had gone home. Like they had days before. On many different occasions. Maybe one of them left the Gatorade jug and the ledge and gust of wind brought it down. Who knows?

Tar paper rolls and hammer drills. We forgot the 3/4” hammer drills!!! The ones that so shook the entire building that it caused the failure of the patio several hours later. Or maybe they nicked the critical piece of rebar that caused the whole roof to collapse but caused no one in the floors immediately below to call the police (oh wait, they just haven’t released those calls yet) or flee the building in the 5-15 minutes they had before the whole thing came down.