Miami Beach, Champlain Towers South apartment building collapse, Part 05 111

[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


SF Charlie
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[NOLAscience]

"Edited to add about the common practice, at the time, of using beach sand to mix the concrete which the beach sand would have salt in it which would corrode the columns from the inside out. It was built to fail."

I found this in a YouTube comment. Is this true? If so, it is sickening.

 

[Demented]

"Edited to add about the common practice, at the time, of using beach sand to mix the concrete which the beach sand would have salt in it which would corrode the columns from the inside out. It was built to fail."

I found this in a YouTube comment. Is this true? If so, it is sickening.

I last witnessed this with my own two eyes at a concrete pouring for for a high rise in Miami in 2019. Beach sand and fire hydrant water used to bulk up the short mixture on the ground floor slab. Spray galvanized SEB's inserted as well, randomly mixed in with the hot dip, along with out of code nelson studs welded on poorly.



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

 

[NOLAscience]

someone posted info on where exactly Eric Zion lived in NYC,

No one posted "where exactly Eric Zion lived in NYC". The point was just that he may have been driving in from NYC. We don't know that yet, but maybe someone will find out where he was coming from. No one is advocating stalking and harassing this person. BUT, I know that investigators, and perhaps even police detectives, sometimes read this forum for ideas on what is possible. So stating an idea for investigation here means that someone might look into it.

The reason why there are so many different disciplines in here is actually to make it easier for the structural engineers.

It's also a difference in interest. I think it's good for all disciplines to participate. Many from mechanical and IT have helped explain what would be expected with a building of this vintage, etc.

 

[Teguci]

I believe that slab drop is 1'-11", not 11".

There are 2 versions of this drawing. One undated version shows the 30" drop and the other undated drawing shows 18". The pictures seem to scale to the 18" version and the North tower also show an 18" step (maybe the earlier version was to provide for putting a proper slope on a plaza deck - the plaza drain plan indicates slope lines).

However, my thinking evolved after it came to light that the surface level parking area along Collins Ave may have collapsed virtually at the same time as the planter area around column M11.1:

Eyewitness from room 111 reported that there was enough time between a loud crash and the observation of the plaza slab failing and then enough time from the plaza collapse to the building collapse for her family to escape. Punching shear is usually instantaneous, so the load crash would seem to be from an earlier trigger event. Further, I haven't been able to find an explanation why punching shear would occur at night without some other preceding event. Do you have any ideas for other triggering events? I do believe that the plaza failure, once initiated, happened like a quick wave radiating from the planter failure.

I think the final building failure occurred at K/10 when the weight of the failed plaza slab was applied to the "beam A" which then applied moment to the building column. Not entirely sure why there was a pause , but I'm glad the family from 111 was able to escape due to it.

 

[NOLAscience]

I for one don't care where any of these parked their cars, but I find that knowing about it is no different than knowing where any of the other residents were as they observed/heard the various events unfold.

Exactly!

 

[Demented]

Further, I haven't been able to find an explanation why punching shear would occur at night without some other preceding event. Do you have any ideas for other triggering events

Weather and a flooded deck. Overweighting the damaged slabs with water, especially when it rained just a little bit more that night, could very easily punch shear at random with no other initiating factor.

Pretty sure with a cracking overweighted slab, we'd here banging and popping noises similar to construction noises as the slab cracks, stretches, and shears the rebar.

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

 

[NOLAscience]

And as for not believing that the other guy would leave that complex to check into a hotel, just because the power had been cut to the unit they were going to stay in, I suggest that you have never tried to sleep one single summer night in Miami with no AC, especially if you are used to cooler nights. Totally plausible. Ask for a night's refund the next day.

I've spent many post-hurricane nights on the Gulf Coast in a house without power. We have never gone to a hotel.

His mother owned condo, so there would not be "a nigtht's refund".

What is suspicious about the sudden hotel stay is the following:
He stated that he had just returned from a trip/travel with his wife. What did he need? Presumably he had his toothbrush and could hand-wash his skivvies if they all needed laundering. He spent a lot of time (1 hour) trying to get the power on (or was he gathering valuables?) and more time (30-40 minutes) getting other necessities after midnight. Most people would rather be showering and getting some rest in the hotel that they paid for.

 

[Spartan5]

As speculation goes, I do think that the people in the garage angle is a bit more plausible than the roof falling off angle.

 

[NOLAscience]

As speculation goes, we don’t even know that the CCTV footage was “triggered.” In fact, considering that angle doesn’t offer much from a security standpoint, why would it be?

I think that security camera has that view to get a view of the pool area, in case of excessive people in the pool (an unauthorized party) or in the case of a drowning. Maybe someone with knowledge of condo security cameras will have more info.

 

[NOLAscience]

On Floor 2, all three phases were dis

tributed approximately equally, from a 3 phase 600A 208V sub-main breaker on that floor (this is where individual meters were). That is, 1/3 got phase A 208V, 1/3 got phase B 208V, and 1/3 got phase C 208V. Of course, the 120V went along for the ride.

Aren't those Electricals so cute with their talk of phases, breakers, and neutrals?

 

[Spartan5]

I think that security camera has that view to get a view of the pool area, in case of excessive people in the pool (an unauthorized party) or in the case of a drowning. Maybe someone with knowledge of condo security cameras will have more info.

That sounds feasible. In my limited experience with CCTV, you can use a mask to exclude the areas where you don’t want movement to trigger the camera.

Notice that bush waving around in the foreground to the left. If this was a motion trigger, the bush would have likely triggered it. If it was a mask and it was activity in the pool they wanted as a trigger, they would have masked everything but the pool.

It’s weird to me that the footage faded in from the “no video” screen. Go frame by frame from the beginning to see it. If it were a constrained clip of some sort, starting with a trigger, wouldn’t it start with a static screen and a play button, or after being selected from a catalog of clips?

 

[jbourne8]

Demented, The deck seems like it was actually sloped from the tests that he did and those 2020 board meeting notes btw.. it said that he needed to do more testing to confirm though, and I couldn't find any info on those further tests.

NOLAscience, I'm sorry, but your insistence that this is a good place to investigate victims is the main reason I'm leaving this thread. It's sick.. let them have their privacy. I'm sure the cops are going to ignore every single one of your posts about Eric because they're all so misguided. And saying we need more information on where they were parked so we understand their statements is totally incorrect, we know that no one could have entered the garage without seeing the rubble pile. Digging for that info is just a gross attempt to place blame on someone more specific, to gain some traction to these insane theories that someone maliciously killed over 100 people and then waltzed off to a hotel for the night. And if you manage to get a specific person into a few lay people's heads that are reading these threads.. they can run away with the info and get crazy with it. It's happened time and time again with internet "web sleuthing."

I want no part at all in a forum that thinks it's okay to witch hunt any of these people. I honestly thought this was a group of professionals that wanted to discuss the building, but clearly some of you are not. I'm out.

 

[SFCharlie]

Can someone tell me this is not what it looks like.

is this some kind of Rorschach test? I see a huge black yellow jacket, with it's head center left, and it's stinger pointing down center. What do you see?

SF Charlie
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[NOLAscience]

I'm also curious about Demented's question earlier:
Quote (Demented)
Does anyone by chance know what the theoretical compressive strength of column M11.1 should have been in an ideal environment?

Turn on captioning and go to Settings (gear icon) to select English translation. At about 8:50, he says that one column of the type that we are interested in would have
a capacity of 320 TONS. Impressive.

https://youtu.be/c-1wwF_STiY

EDIT TO ADD: This is a FANTASTIC video, and well worth the 30 minutes. It is so fast-paced; after the intro, the video is packed with information with technical ideas presented in a way that almost anyone can understand. He uses a very nice 3D model and even some cardboard mock-ups of different structural systems.

I think he has an error in his calculation of live load, which he calls "overload". 40 psf is 200 kilos/sq meter and he says (or the translation says) 300 ksm. Also, I don't see that he used any live load reduction, discussed on Thread 1 or Thread 2 of this forum discussion.

 

[SFCharlie]

It's very hard to make out though, so I'm not sure that's correct.

How is it possible to see "sky" when I'm looking down into the garage?

SF Charlie
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[waross]

Good catch Nukeman948, thanks. Correction made.

Aren't those Electricals so cute with their talk of phases, breakers, and neutrals?

Back at you:
Aren't some of those those Structurals so cute with their mangled understanding of phases, breakers, and neutrals?

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

 

[tmwaits1]

One thing you can see looking through the original plans is that the designer changed the foundation design from closely spaced precast concrete piles (PC) with a capacity of 50 tons each to a pressure injected footing (PIF) with a theoretical capacity of 150 tons each. This was clearly done to reduce cost as it allowed 2/3 of the piles to be removed. The revised layout with significantly greater spacing is shown in the drawings but the change doesn’t appear to have been incorporated correctly into the foundation design as there are some missing details.

 

[AutisticBez]

Okay, what about the giant crack in the foundation slab between the ramp and M10 column? I understand that the ramp at the bottom sits on a beam between the two pilings / columns next to the ramp. Why is this slab cracked? It's a giant crack along the ground. You can see it in the video. It's about 50% between the two columns. Could there be a settling issue of the x10 columns? Why is the crack there and not between x10 / x11?

Perhaps there is a foundation issue? You have water seeping into the foundation in this region. This region is the region that failed the building. This spot seems to be where the trigger and cause will be found right?

If it's roof slab failure, then the roof hitting the pool deck just above here is the trigger, but foundation issues could also be an issue. Soil underneath this area could be a problem. How can you get such a crack on a foundation slab? Surely that thing is thick as and is resting on the pilings right?

 

[Mark R]

No one posted "where exactly Eric Zion lived in NYC". The point was just that he may have been driving in from NYC. We don't know that yet, but maybe someone will find out where he was coming from. No one is advocating stalking and harassing this person. BUT, I know that investigators, and perhaps even police detectives, sometimes read this forum for ideas on what is possible. So stating an idea for investigation here means that someone might look into it.

The actual address was surely posted earlier, it may have been removed out since many people commented that it wasn't appropriate. The original posted actually live to street address etc. in NYC.

Aren't those Electricals so cute with their talk of phases, breakers, and neutrals?

They are actually providing some good information to correct some misinformation that's been given. Although I'm not sure exactly what difference the electrical discussion makes because it certainly wasn't the cause of the collapse.

 

[Js5180]

What I am hoping, as a long shot, is that some combination of electrical arcing or lights being on or off can positively identify a floor or room in the collapse video at a specific time. If that happened, then we can tell whether the penthouse is present in the falling stack at or near its original height, or if it has compressed ahead of the floors below it.

Regardless of where else there was instability, collapsed slab, etc., a roof collapse of any kind could easily be the final trigger. That’s why I see the electrical discussion as relevant.