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Miami Beach, Champlain Towers South apartment building collapse 151

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dold said:
This "40 years" is a completely arbitrary number as far as i'm concerned.

Dr. Atorod Azizinamini, a structural engineering professor from FIU, is advocating a much better approach than 40 years:

I encourage you to watch his video in full, his thoughts on this disaster are worth your time. The short version, however, is different levels of inspection at 5, 10, 25 years, or something like that; so you have an expert eye taking a quick look far more often, and a detailed examination at longer intervals.
 
Dik,

I apologize if I seemed flippant about the design of the Parkcade (I really love that term), it was not my intention. What I was trying to convey is that failures during construction, or soon after completion are different than a structure that has been up for 40 years.

I totally agree that the bars appear to to not have has adequate concrete coverage and became unbound to cleanly from the slab/deck. this in not engineering 101. This is a pretty specialized forum, and I think that the general level of discourse reflects that. My point is that there is a huge knowledge gap in understanding structures such as a Parcade between the members of this forum, and the general public.

We are a self regulating industry, and I would wager a $2 bill that several members of this forum are either current active members or former members of at least one code committee.

In my opinion I feel that we fail the public post construction, in terms of inspection, and maintence codes for mid to high rise residential buildings.

There is no doubt in my mind that the people are actually reading this, could have prevented the loss of so many lives.

The type of professionals that participate (myself included) in discussions such as this, are the ones that write the building codes, so in a sense we are all responsible for this catastrophic event.
 
News interview from a sister of one of the missing: (from Apt 412)
"Suddenly she says, 'honey the pool is caving in, the pool is sinking to the ground'," "He said 'what are you talking about?'
And she says, 'the ground is shaking, everything's shaking' and then she screamed a blood curdling scream and the line went dead."

Link:

In 2018 MC [Morabito Consultants] Structural Report recommends that the Entrance/Pool Deck concrete slabs that are showing distress be REMOVED & REPLACED in their entirety.

Link:

Florida_Condo_Collapse_9_es00ak.jpg
 
missstructures, about that 1st floor survivor. I would guess that he exited his condo into the interior hallway and ran for the street entrance, which is within the still standing tower. Once he made it into the hallway portion within the standing portion he would have been protected.

Separately, as was mentioned earlier, NIST investigators are on the scene. This from yesterday.
nist_rnmraw.jpg
 
jrs87 said:
Kreemerz, no offense was meant, I assure you. I asked if that was your intent, that is different than calling you one.

There is a toolbar with icons in the editor that help you form your post. The term "Good grief..." in this neck of the woods is sometimes pejorative and mocking.

Hope, we are past this now with no worries and back to the subject.

P.S. Corrosion is form of energy like seismic activity. So corrosion plus gravity equals structural damage. Right?

Wow... that's an interesting way of handling being rather direct and potentially hostile to a guest here... calling someone a "troll" on account of them using a commonly harmless idiom that only

might be pejorative or mocking. I've never heard of a such a thing. Good grief is an expression of surprise, dismay, alarm or other emotion. The only one who has the right to be upset might be God since it's derived from Good God...

In any case, thanks for pointing that out. Intriguing.

Thanks for explaining the report's discussion of "structural damage". I wasn't clear on what the report was referring to when they said that. But now I am.

 

No need... wasn't taken as such... I just wanted to let people know that drainage is critcal for parkades... generally to minimise corrosion issues. Also need good expansion joints. You either install cheap ones, or ones that work.

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

-Dik
 

Thanks rapt... in Winnipeg, we typically have one freeze-thaw cycle per year...[lol]

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

-Dik
 
dik said:
drainage is critcal for parkades... generally to minimise corrosion issues.

Corrosion is supercharged in spots where it's constantly damp and constantly exposed to air. You can see this very visibly on steel canal boats. You get a roughly half inch band of much faster corrosion at the waterline; the metal that's constantly submerged is good, as is the metal that's generally above the water. That's with sacrificial zinc / magnesium anodes welded to the hull to slow it down, and reasonable attempts to protect it with coatings. Just giving this as a practical example where you can see it in action.

A flat surface that doesn't properly drain / dry out is creating that sweet spot for rust.
 

He simply asked if you were being one... Your kurt comment could not have been taken another way, IMHO. I ignored it. Let's drop this.

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

-Dik
 

Your typical 'real' load on a parkade structure is in the order of 15psf to 20psf as a maximum load and I use these values for alternate LLs.

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

-Dik
 
Dik said:
Thanks rapt... in Winnipeg, we typically have one freeze-thaw cycle per year...lol
Surely a slight exaggeration. grin.
We have a couple of months in both the spring and the fall with a daily freeze thaw cycle. The daily freeze thaw cycles for a thermal mass are very much shorter. Is that what you were refering to?
By the way; Does Portage and Main still claim the record for the coldest intersection on earth?

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

Seems that way.. but, there are likely colder intersections in Siberia, etc. Winnipeg is colder than Moscow...

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

-Dik
 
A new kid, here.

This topic is (unfortunately) interesting.

I note that two witnesses appear to be saying that the "pool deck" failed first, by perhaps a minute or more. To me, the pool deck is the expanse between the pool and the building. Photos show it surely did drop, by one level, I think.

I propose that by having that floor drop, there was then, for the soon to fall building(s), nothing to keep the intersection of their columns at that same level from moving towards the south (towards the pool deck location). I am assuming a solid sheet of concrete across the whole expanse, and I believe it likely there was a garage under the whole thing. The building could stand until some perturbation caused the sideways movement of those points on the columns, and they fell.


spsalso
 
He would have been blocked from seeing the pool deck by the still standing buildings. It appears it happened and he missed seeing it.

One of the witnesses was in one of the buildings that fell, and said something about the pool area acting funny. So it surely seems like that HAD to have happened first.

spsalso
 
I'm with sdh4 and dold.... the pool deck could have racked the columns along column line 9.1

That would explain the sudden collapse if several columns were able to fail nearly simultaneously
 
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