Miami Beach, Champlain Towers South apartment building collapse, Part 14 41

[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
Miami Beach, Champlain Towers South apartment building collapse, Part 10
Miami Beach, Champlain Towers South apartment building collapse, Part 11
Miami Beach, Champlain Towers South apartment building collapse, Part 12
Miami Beach, Champlain Towers South apartment building collapse, Part 13

SF Charlie
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[MaudSTL]

I posted multiple links, as the Herald published three articles simultaneously.

 

[Demented]

@Optical98
A collapse starting along the shear wall and elevator shaft has been looked at since the first few days after the collapse. Chloride corrosion, poor concrete cover on the bottom of the slab leading to rebar unzipping, and an extreme lack of reinforcement between the thin slab and shear wall, and of course the cantilevered forces acting on the columns at the drop connection.
The valet drive having been repaired in the early 2000's by opening the spiderweb cracks to 3/8" wide by 1/2" deep and filling with caulk before topping with paver bricks didn't help it's structural integrity any.
Nothing really new that anyone's onto. Many CE/SE's pointed that failure path out almost day 1.

Up on the 9th floor where the Gonzolez family had enough time between floor collapses to find each other and make sure the granddaughter was covered by the grandmother I believe it was, has been where I've wondered if it has been slabs/walls failing in the upper levels before the structure fell. They had reported the slab in and just outside of their bedrooms sinking and failing before collapsing down to the 8th floor, before eventually falling down to the 5th floor as the building collapsed. The Nir's reporting sounds of a wall collapsing above them tickles that idea in my mind, plus being under the tie beam supporting the AHU that was replaced/repoured in one of the remediation projects without inspection of the rebar, of which after the collapse we have been able to see there was no rebar at the beam to column connections.

That entire area was weak, and almost as if it were built with no physical connection between the slabs and wall, aside from minimal horizontal rebar at what appears to be almost 24" spacing in places.

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

 

[Optical98]

I wasn't trying to imply we were the only ones to discuss this area, but we had just decided to circle back and focus more on the shear wall/elevator shaft anomalies etc.

Epoxybot was the first one on here to say they thought the failure started along the shear wall. I didn't join until page 5 or 6.

 

[MaudSTL]

Up on the 9th floor…

From the Witness Statement Timeline: “ "On feeling the building shaking ""like an earthquake"" and hearing a sound like ""thunder,"" Angela Gonzalez rousts her husband and daughter to run. Angela and Deven Gonzalez (904) run out of the bedroom door. The floor opens up and they fall from the 9th to the 8th floor. Angela grabs Deven and they fall to Floors 4 and 5, ending near the top of the pile."

The hallway outside their bedroom door was inside the apartment. In other words, it was not the public hallway outside the apartment.

>>>>>Edit: Here is Morabito’s drawing of the 9th through 11th floors. Wouldn’t 904 be supported by E2? If so, it’s beyond the shear wall connection.

 

[Optical98]

Maud

If you go back to Part 11 on this thread and search "elevator" and unit 811, you will see how this discussion came about, I was asking about Raysa's comments and why there seemed to be a delay in the 8th floor collapsing etc.

 

[MaudSTL]

@Optical98, I was responding to Demented.

 

[SFCharlie]

There are simply no defects in the construction of this structure

...missing rebar at column slab joints???
...soupy concrete???
..lack of drainage (slope)???
..shear wall of (what ever they call cinder block now)???
..rebar in slabs with inadequate cover???
And the beat goes on, the beat goes on...


SF Charlie
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[Nukeman948]

..shear wall of (what ever they call cinder block now)???

Good evening Charlie,
Could you elaborate on the block you are talking about in the shear wall? The only place I have found where they used block in the shear wall is where the stairwell door originally opened to the east through the shear wall. It was blocked over and they moved the doorway to come out on the west side of the stairwell as shown in Fiorella's video. It appears they shortened the vestibule for the door but left it's corner column. (The door is partially hidden between that column and a traffic cone.)
Screengrab 4:28

https://youtu.be/w4rGWH7aDJc

 

[SFCharlie]

Quote (Optical98)
This is more from Dawn Lehman and the Miami Herald. I can see snippets on twitter but links are behind a paywall.

The archived version of this piece, which anyone can access, was provided earlier in this part. Although some of the images don’t make it into the archive, many do.

These images are on twitter, but not in any of the stories I've seen behind the Green Door (I mean the firewall).

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[SFCharlie]

Quote (SFCharlie)
..shear wall of (what ever they call cinder block now)???

Good evening Charlie,
Could you elaborate on the block you are talking about in the shear wall?

It appears to me that in several places that a lot of buildings have shear walls, (around stairwells for instance) Concrete blocks of some composition were used,,,not to say that wasn't what was called out on the prints, but the excuse of allowing the architect to allocate the walls and spaces "later' doesn't make sense in this instance...
just saying...



SF Charlie
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[MaudSTL]

These images are on twitter, but not in any of the stories I've seen behind the Green Door (I mean the firewall).

Those images all made it into the archived version too.

 

[spsalso]

...a lot of buildings have shear walls, (around stairwells for instance) Concrete blocks of some composition were used...

"shear walls" and "concrete blocks" don't go together, in my opinion.

Perhaps the world is different in Florida.


spsalso

 

[Demented]

Not even in Florida.

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

 

[Nukeman948]

SFCharlie

Well, my question was if there were any other known locations of CMU block used in this shear wall.
There were two doorways that were designed into this wall that could have easily been avoided by putting the door to the stairs and maintenance rooms in different locations. It almost seems like these openings were designed as stress relief to allow a per-determined amount of flexing to prevent fracturing. Filling with easily crushed CMU shouldn't cause any harm and even survived demolition.
I dunno, mabee i bee dum.

​

 

[Demented]

12th floor stairwell may have had CMU patching holes in the wall, but other than that, should be no other CMU.

Edit: Charlie, you may be getting confused with all of the interior CMU walls around the shear walls, but the shear walls were not CMU.

 

[SFCharlie]

Thank you NukeDude948 and Demented (Maybe I was confused by the stair steps south of the elevator?)(near the top)

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[Optical98]

Where CMU blocks may have fallen onto elevator cars.

 

[Demented]

Shear wall and the failure point for ref.

 

[Optical98]

Does anyone recall if there was an estimated or established timeline for the Unit 711 video? That video shows the wall between the 10 and 11 stack leaning into and slightly downwards if I recall. I'm thinking it's indicative of the east wing detaching from the shear wall. And we can hear a loud snap.

I know I'm being a bit lazy, but also slicing n dicing in the kitchen atm ^^
Happy Turkey day all o/

 

[Nukeman948]

*bangs head on desk*

Back to our regularly scheduled absurdity.

Happy Thanksgiving you nerds.​