Miami Beach, Champlain Towers South apartment building collapse, Part 06 131

[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

SF Charlie
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[Auri]

Auri, those are three beams that were above the garage level columns that were just to the east of the garage entrance

Thanks a bunch for that. Those are precisely in the drop down location. I had not thought to look for the beam schedule as they appeared much too tall; the recovery crew instead cleaned all around them but had no need to remove them with nothing trapped underneath.

Can anyone explain how this 12th Floor PH parapet is on the bottom of the patio deck pile, where deck did not fail

The first mid section of building basically fell within footprint, and it's an unimpeded fall for the 12th balcony and roof in the stairway exit area:

 

[Santos81]

not sure I know which kind of why you're looking for

It doesn’t really work as drawn with the ramp down in place. Nothing really holding the load from the generator room.

It depends entirely on the integrity and the skills of the engineer. His skills appear to be maybe more than adequate.

Allyn is a great choice and it’s not a question of his skill or integrity. I cannot say the same for whom he is preparing his report for and what they may choose to include or redact.

 

[Spartan5]

I cannot say the same for whom he is preparing his report for and what they may choose to include or redact.

What are you suggesting their liability or motive is in this?

 

[dik]

@Spartan, You forgot to add the smiley... it might be a little suspicioius that they dropped the adjacent building on a 'crime scene'... but refused to allow qualified technical people take a look at it.

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

-Dik

 

[Santos81]

What are you suggesting their liability or motive is in this?

There’s been too much focus on the 40yr Re-Certification of a building that was designed for a 30yr life.

Miami-Dade County requires an ANNUAL Minimum Housing Standard Inspection of which incorporated municipalities perform on their behalf. These are included in the FOIA documents. On top of that, there were Building Officials on the premises for various inspections every 3 DAYS on average. Their focus unfortunately seemed to be limited to Sea Turtle Lighting Compliance and nuisance WWOP complaints which served to highlight the complete and total clusterfuck that department is.

 

[Santos81]

it might be a little suspicioius that they dropped the adjacent building on a 'crime scene'... but refused to allow qualified technical people take a look at it.

So those from NIST, Army Corps of Engineers, and engineers retained by FEMA, Miami-Dade County and the State of Florida don’t count? Allyn’s suggestion that KCE had not had any access to the site and the staging area where evidence is taken for reconstruction is completely misleading as well.

 

[jbourne8]

The full 45 minute recording of 911 calls was released -

https://www.youtube.com/watch?v=gXGIWSkfW1s

It's interesting how the first person who calls in calls it an explosion at 1:16. Saying it sounded like an accident made a lot of sense, especially since part of that slab looks like it fell on a car.. but explosion seems like an odd descriptive word for slab that's fallen.

Tropmet, Yea.. about that pic too, there was definitely a maroon car parked in that spot 39 next to the column too, I watched them pull it out of the rubble yesterday.

 

[clouditguy]

I've been reading these threads with great interest for weeks, some great and interesting discussion and analysis.

I think the most revealing evidence is the ring video as it's the only progressing evidence. I've been doing some assessment of this to post shortly (did try to post it before but the long post didn't post and needed to build up to posting it again!!). However I have one immediate simple question.

I'm not a structural guy so apologies for any naivety. But in the ring video, the pillar or wall beside the door goes from straight to perpendicular prior to full collapse, with no obvious sign of broken slab (punch through or similar).

To this layman's brain, this means that the vertical gap between floor and roof slab must have reduced at this point unless I am missing something?

There's only two ways this could occur if this is the case - either the floor slab INCREASED in height (can't think of a single failure scenario that would cause this), or the roof slab dropped?

If the roof slab dropped, does this actually add credence to the roof failure scenario? I should stress that this has never been my personal thought on likely failure, so not trying to prove this, but this is troubling to me in terms of something not going on higher up the building?

I'm sure I'm misunderstanding something...

 

[zebraso]

there was definitely a maroon car parked in that spot 39 next to the column too

Maroon? There is some pretty strong maroonish trace under what has been referred to as the fallen slab.

 

[jbourne8]

zebraso, the maroon car I was referencing is further back in the garage.. in spot 39. It was very flat when they pulled it out, it was late yesterday. It's a comment about this pic though, from further up in this thread.

 

[Murph 9000]

It doesn’t really work as drawn with the ramp down in place. Nothing really holding the load from the generator room.

Isn't it showing a beam running along the L & M lines either side of the generator slab? Somewhere in the various documents, they mentioned it being a 250kW generator. Taking a Cat D250GC as an example, that's a dry weight of 5324.2 lb to 6735.1 lb. It's not lightweight, but it's also not going to require a crazy amount of structure.

Why there? My guess is that it was simply a bit of space with limited potential for use, but big enough for a generator and crucially had sufficient exterior wall for cooling air grilles. A standard diesel generator produces about the same waste heat as electricity, so it has up to 250kW of heat to dump via airflow through those grilles.

 

[zebraso]

further back in the garage.. in spot 39

Yeah it's a long shot again. I just read "maroon" and I knew I saw that maroon in my image and thought it did not belong there back when I first looked at it in the sense it was out of place. I know people will say it's a spurious artifact, but there are not too many all colors or the rainbow stuff like chroma interference moire so it occurs to me that there is something to it. It's just hard to say it out loud (again). I have to note that there is not much depth reference in the image. A lot of what the depth of anything appears to be is based of a loose collection of reference points. I just try to keep and open mind.

 

[Santos81]

Isn't it showing a beam running along the L & M lines either side of the generator slab?

Slab Drops with ties from non existent slab into nothing but air between L/1 and M/1.

 

[warrenslo]

I like your theory. That's been rattling around in my head for the past couple of days, too, but I didn't put it into words like that.
What is your explanation for the 5 to 10 minutes between the failure into the garage and the building collapse. Why does the load redistribution take that long?

Deformation Theory of Plasticity in Steel.
Concrete works in compression. Steel works in tension. Concrete needs steel. Steel rebar is used for tensile strength.
Steel gets stronger before it fails in tension, yes it's bizarre.

This is why wood high rises in earthquake zones (currently CLT lumber but my bet is we figure out how to just use studs with shear walls with an occasional transfer one day) are a new goal.
Wood performs superior in unusual events, making it an amazing building material.
Wood works in both tension and compression, along with not just failing out of nowhere like concrete (steel slowly fails too)...
Concrete moment frame construction in CA is now severely limited (practically banned) after the 1971 San Fernando and 1993 Northridge earthquakes.
There's no plan B to failure in a two-way moment frame concrete slab construction, it's not safe over time.

 

[zebraso]

in spot 39

One more time. I'm a little slow sometimes. There may be a faint trace of maroon in the area that would be spot 39. I don't know what else that color is. It's in the purple range. Not as strong as the purple color is shown up front where there is more light. I'm not saying this information is worth anything. But it might show that camera can detect colors in dim light (or not).

 

[jbourne8]

zebraso, all I saw there was a black spot.. that's actually what drew my attention to it, was how dark that spot was. I think the back wall of the garage looking green in most videos is kind of proof of how crummy that camera is really. The entire back of the car looked completely in tact too.. so I doubt it was missing a back bumper or something, if that's the suggestion.

 

[hochhaul]

I'm still lurking but nobody has changed my mind. The roof anchor work caused the penthouse roof to collapse onto the pool deck.

Your theory is far more probable than some here want to admit. Nobody has accounted for the report that Elena Blasser, living in Penthouse 11 (12th story, x11 stack), was awoken by loud creaking noises at approximately 3 or 4 AM the day before the collapse. Her son said that she was so disturbed by this loud creaking noise (as in, it was not a normal occurrence for a person that had lived in the building for years) that she was unable to go back to sleep. Considering nobody else in the building reported hearing "creaking noises" would suggest that she was the closest in proximity to the source of the noise. She was directly below the section of the building that appears to be missing a parapet in the security camera collapse video. In the days leading up to the loud creaking noises, contractors were attaching davits to the roof slab and load testing them. The Association Reserve report from 2020 noted cracking at the parapets and the engineer instructed contractors to inspect and repair any damage to the roof slab. Sara Nir stated that she first heard noises at 12:45 AM and that those noises seemed to be coming from ABOVE her. She said those noises continued for at least 25 minutes and became increasingly loud. At 1:10 AM she said she heard a sound that she described as a "wall collapsed" in the condo ABOVE her. She then went to the lobby and that is when the garage collapsed (1:15 AM). She observed activity that she thought was coming from above her for a half hour before she states she saw the garage collapse.


The argument challenging the roof theory is that nobody called 911 from the top floors -- there were many calls made to 911 that the media did not mention in any of their reports. In one call placed to 911 from the building, the operator answered the call and the call was disconnected, as though the caller was caught a collapse at while making the call (1:17:06 AM). Others could have been sleeping when the structure above started to fail (if that's indeed where it started).

There is a reason Allyn Kilsheimer was taking core samples from the penthouse. He knows better than to simply dismiss the noises Elena Blasser heard the day before the collapse, the video showing a missing parapet, and the fact that contractors were actively working on the roof in the days leading up to the collapse.

Entertaining the idea that the series of events began at the roof doesn't mean that the building collapse wasn't caused by column failures at the garage level. A failure at the roof could have triggered the events at the pool deck. There's no justification for ignoring evidence pointing to the roof.

The overflow scuppers were not the primary RW drainage outlets for the roof or UPH parapet balcony. Their base elevation was 7” above TOS and incorporate spring loaded doors.

I don't see spring loaded doors. It appears that the scuppers were no more than 5" above the top of the gravel/flood coat.

 

[AusG]

The problems with the roof theory include:
[ol 1]
[li]The main roof and at least most of the parapet seems intact as the top of the building rotates and slumps in the CCTV footage. Floor-matching with the late-falling section shows no missing floors.[/li]
[li]Identification of roof items at the bottom of the debris pile or in the garage is unconvincing.[/li]
[li] Lack of 911 calls for the upper floors, maybe. [/li]
[/ol]
Probably other items indicating that design, construction and maintenance problems with the pool/patio deck are enough on their own.

Occam's razor only fits the roof theory if you discount the floor-matching by numerous analysts of the CCTV footage, and other recognisable features in the video. If you accept that a floor has descended in the first-falling section prior to the CCTV, Occam's razor needs no involvement from the roof. It remains possible that some small damaged section of parapet is initiator - the pool deck was obviously a weak link and ready to let go anyway - and I don't think anyone here has discounted that possibility.
Allyn Kilsheimer is not directing operations, at least according to his interview, so who is coring what and why is an open question.

 

[zebraso]

I doubt it was missing a back bumper or something, if that's the suggestion.

No. I'm trying to cut down on being obtuse. I really missed the context of how far back this was in reference to. And I agree with where the columns are said to be although it's almost impossible to actually see them. Although looks like something is actually leaning against M12.1 (like a broom that probably is not a broom). I tell myself the columns are there because they have to be. The purple color along the fallen deck in front is a mystery as far as I am concerned. I could just say "artifact". That's the easiest way I guess. Whatever the case, it does not seem to have any significance at this point. The teal colored thing would seem to be well in front the column between 39 and 40 because I don't see anything that near the back wall being that well lit or is it just that the area is not obstructed by debris? I'm assuming there is a dust cloud in there and that is why some areas look opaque. Otherwise the lights should illuminate all the way back?

 

[Retrograde]

The argument challenging the roof theory is that nobody called 911 from the top floors

In my opinion the burden of proof lies the other way. There is no solid evidence supporting the roof theory (and plenty against it as pointed out by AusG); and unless some is supplied, the theory cannot be taken seriously.

Given you joined the forum two days ago, I suspect a sock puppet account.