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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[zebraso]

There is not enough energy being imparted to blow the mayor's toupée off.

Good information. You must have seen the same episode of Monk that I did. I did know that sound travels faster in water than air. But I don't think I thought of it much in terms of soil before. I assume the efficiency is inverse as frequency. I am all too aware of the guy down the block with the oversized subwoofer. And I don't wear a toupée.

For some reason I am reminded of the worker doing blasting in the street in front of my house to lay expanded sewer lines to a new development. They were monitoring the boundaries of housing to recorder shock levels (for liability). So I asked the worker (who could not shake my hand because of nitroglycerine), if the inverse-square law applied to blasting. After I explained what that meant, he indicated it did not and so it did not matter if he did not place the sensor at the closest point. I am skeptical. He had kind of a lame excuse for not doing it that way. Not that this has anything to do with anything. But how does the inverse square law not apply?

Edit: Incidentally in the above case the blast did knock the stucco off the basement wall in the house where I thought the probe *should* have been placed. I don't think the owner bothered to seek restitution *rolls eyes*.

 

[AusG]

Acoustic (the word I should have used in place of audio) velocity is positively related to density hence in water much faster than air, 1500 m/s. In soil it is complex in detail but in a gross sense is related to both density and strength, especially the shear wave. There is a useful correlation between shear velocity and a penetrometer test. If you think of it as a being transmitted by a million little springs, harder springs will zing the sound along faster than spongy ones. For e.g. too the NIST folks are using a sonic tool to investigate the strength of the CTS concrete. Frequency: Like light in the atmosphere there is a window of transmission. Earth materials attenuate sound rapidly beyond ~120 hz, but in the range 4 to ~120 hz it is used for petroleum exploration to great depths.

 

[zebraso]

I agree with Zebraso and would caution

I am also guilty as hell. I can't even follow my own advice. It's not scientific at all. It's the opposite. I think it's the emotion of the whole ungodly thing. Listening to people that went through this....

 

[zebraso]

4 to ~120 hz it is used for petroleum exploration to great depths.

Ah yes. You were talking about image interpretation about 8 threads ago. Above 120 hz I would guess it's falls off > 12 dB/oct. So basically we are not talking much or at all about "sounds" or what would be referred to as "audible" noise in the sense of monitoring for OSHA (as an example) hearing safety limits. And I know hearing goes down to 20 hz. But in terms of perceived noise levels in the environment it does not contribute much typically. For example the real issue for hearing protection on GTC around jets is above 20 Khz which can't even be heard. So it's not about how these energy sources are perceived. I mean that's why these guys go deaf. It's not that "loud". They learn the hard way to put the ears on, too late.

 

[Demented]

Thank you! I was so pleased to see this. I have been going through the long bodycam videos and plan to update the Timeline this weekend, now that we have a better idea of what Shamoka Furman experienced. In one of the long videos, she states strongly that there were three collapses…just as Gabe Nir did. The big difference to me is that she perceives the first collapse as something with the elevator, which would make sense since her desk was so close to it and the sound would have traveled easily through the elevator shaft. Unlike the Nirs, she does not mention thinking that the sound came from above.

I have also watched and logged all the bodycam appearances by the Penthouse 12 Blue Shirt with Badge Guy. One thing I noticed about him is that he mentions his wife and kids to both the cops and Fire. However, I can’t understand what he says about them. I also noticed that he seems more comfortable talking to Fire, which makes me wonder if he’s a firefighter. Unlike Shamoka, who is disheveled and covered in dust, Penthouse 12 Blue Shirt with Badge Guy is tidy and clean. But he does at one point make a statement about looking down and seeing the collapse, which could put him in 1208 or 1209 if he’s from CTS instead of some other building. As BKNJ said, he is likely to be from some other building. I don’t think we have enough info about him to place him, plus he only tells us about hearing the deck and the building collapse, so no new info of value to our inquiries.

I'm 99% certain on this.
"I'm a city event foreman" - Blue shirt man with a badge
Regular badged civilian.


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

 

[BKNJ]

https://www.youtube.com/watch?v=1BSHmIQQioQ

Note that at 5:40 Argentine actor Nico Vazquez asks police for help, reputedly for his injured wife (I don't understand enough Spanish to be sure), at 88th and Harding but the officer rebuffs him as he doesn't speak Spanish.

BTW, I realize 911 was called before the main collapse, but I'm amazed how many police and fire were there within about two minutes of the collapse.

BKNJ

 

[1503-44]

He seems to say his woman is burned, "quemada".
"Herida" is wounded or injured, but that doesn't sound anything like that.

 

[gonefishing2]

Perhaps we can call this sort of an executive summary of the potential list of rabbit holes that need to be pursued with factual data verification where possible, now that all evidence is in the form of the most complex puzzle you can imagine.

So are we now peeling back the layers of that ‘Onion Razor’ such that we can see there are many plausible contributing ‘stacking’ factors to the sudden collapse of CTS?

I am sure I will miss some of the many factors identified so far, and mis-quote some too, but here is a shotgun quick attempt for consideration. So don’t shoot the messenger…..

1 Subsidence of perhaps piles or columns/foundations, along with increased content of water around garage slab and tub walls?

2 Or perhaps a leaky Surfside Storm and Sewer System/CTS tie-in back flowing around CTS when tides are high?

3 Perhaps the collapsed portion of the CTS RC buildings was designed and constructed on the on the thinnest of margins, which means it was flexing more from wind, vibrations, and asymmetric additional loading of a less than a best practices RC structure? What was the natural frequency of structure and it was surely changing over time as it was flexed, stressed and loaded with new loads.

4 Perhaps pile-driving, roof loading, roof vibrations, roof damage and repairs, poor quality concrete repairs, lack of timely and true root cause structural and water proofing repairs, lack of structural supporting of lower floors during repairs, asymmetric loading of adjacent deflected two way slabs with week slab to column connections, recent rain loading,. I would argue garage ceiling band-aid crack filing actually made things worse rather than better, as rain water had to now find another path thru the garage ceiling, thus crack some more concrete to seek lowest point due to gravity.

5. Starting on the Roof when it was known that pool deck was ticking time bomb, because working at ground level parking deck created a logistics challenge.

6 All of the factors continuing to weaken and loosen up the RC structure?

7 Demolition of CMU non-load bearing walls in some units that perhaps had been providing lateral support to the insufficient lateral bracing flat plate slab and column connections or perhaps was additional lateral bracing the designer was counting on to prevent racking of structure? So not truly non-load bearing from a lateral support function.

8 Navy 3.9 after shock could have contributed a little to a very weak structure.

9 Which might lead one to say Roof work was final insult?

10 Palm Tree loading of concrete structural slab, with roots growing into cracks of concrete deck, and continuing to cause the crack to grow wider, and of course they how were they removed? Roots will chase water sources, but in a sewer pipe that tend to grow in length and fill the volume of the pipe, not necessarily cracking the pipe or at least in my soil which provides lateral support of outside of pipe.

11 Low spots in pictures of patio deck indicate perhaps uneven settling or corrosion of some of the concrete columns supporting deck, other wise deck should be perfectly flat as built?

12 One question is why would it take 40 years to delaminate the patio deck slab sufficiently to cause collapse? It would seem the standing water under tile and sand would never really dry out, except perhaps during a long dry spell?

13 Perhaps this exercise is a waste of time, but it seems compiling a list of really plausible contribution factors and perhaps ranking them or trying to quantify them is similar to what Maud is compiling with her witness statements data base.

Now I am not Volunteering to be the book or gate keeper, so if someone else wants to do that great. I am more of a one and done guy, with perhaps some edits as the memory ‘pixels’ wake up….then I move on to my next interest…..Currently it is my long honey do list…. BTW, I did not re-read this post, so forgive the typo's...

 

[dik]

You missed the big ones... negligence on the part of the Engineer, Condo Association and the Municipality.

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

-Dik

 

[spsalso]

You forgot architect and general contractor. And perhaps some specialty contractors.


spsalso

 

[arbitraria]

Perhaps add in the owners over time, avoiding doing big, un-sexy repairs, thus kicking the can further down the road. (Not victim-blaming, it's an inherent issue with condo ownership...why pay to fix something now if someone else can do it later, when you've sold and it's not your problem anymore?)

 

[Optical98]

All About Money,

Nice list, it would be helpful to see these items across a timeline, with some factors showing as a "constant or static" chronic condition, along with the dated possible contributions leading up to the date of collapse.

BKNJ,

Nico Vázquez's girlfriend Gimena Accardi, supposedly ran into a palm tree during their escape... in pics she has a black eye, more consistent with how people look when getting hit in the face with an airbag.

Demented,

The man in question with a badge, it looked to me like the center of the badge was red, I'd say firefighter.

 

[spsalso]

Perhaps add in the owners over time, avoiding doing big, un-sexy repairs, thus kicking the can further down the road. (Not victim-blaming, it's an inherent issue with condo ownership...why pay to fix something now if someone else can do it later, when you've sold and it's not your problem anymore?)

I suppose you mean the unit owners, as opposed to the condo association.

Neither can be expected to be familiar with construction. And neither had any knowledge that the building could have been built in a shoddy manner (other than viewing the aftereffects).

I just don't see how they could be expected to know that they were risking their lives. And losing. Why would any one of them been thinking before the event that "this building could fall and kill us"? ALL the other people listed knew, or should have known, that there was a risk of dramatic failure.



spsalso

 

[gonefishing2]

Yes the preface to my Executive Summary would be it is ‘All About Money’

Which includes who’s pockets are being lined, and how the lowest paid and skilled workers are in high demand as long as they improve bottom line to the greasing of the rails for Developer/Investors/Government Officials and other ‘tax collectors’ restricting the valve flow. For example the Rodney Dangerfield Rich Tycoon goes to Business School Movie.

https://www.imdb.com/title/tt0090685/

 

[Demented]

@Optical98
That is not a FD badge in South Florida. Nor is it any of the PD's. We give badges, and someties even patrol/city cars, to non LE or FD positions here.

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

 

[Santos81]

That is not a FD badge in South Florida. Nor is it any of the PD's. We give badges, and someties even patrol/city cars, to non LE or FD positions here.

City of Miami FD - Admin; tenant in PH-9 IIRC.

 

[Demented]

They switch badges recently? An upstairs neighbor is MDFD and she still runs this one too.

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

 

[BKNJ]

He seems to say his woman is burned, "quemada".

Nico Vázquez's girlfriend Gimena Accardi, supposedly ran into a palm tree during their escape... in pics she has a black eye, more consistent with how people look when getting hit in the face with an airbag.

Hmmm... very interesting seeing these posts in juxtaposition. I'm sure I don't need to point out to this crowd that airbag deployments can cause burns.

BKNJ

 

[Optical98]

BKNJ

How do we know that was Nico Vazquez talking to the police in that video?

Here's what she looked like after...I don't see burns.

https://www.archyde.com/the-first-p...-plane-that-brought-them-back-to-the-country/

 

[Santos81]

They switch badges recently? An upstairs neighbor is MDFD and she still runs this one too.

City of Miami, not Miami-Dade County.

It’s a fairly specific shield for admin.