Miami Beach, Champlain Towers South apartment building collapse, Part 16 24

[dik]

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

-Dik

 

[SFCharlie]

SF Charlie
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[FJBnomics]

“Catenary Stubs’. Got Love It!

SFC, Outstanding Power Pointy! Now to digest

 

[SFCharlie]

Here is the powerPointy

SF Charlie
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[SFCharlie]

"Over the years" Five Years? I mean, the gravel of the 5 year old "walk" is flowing out where the anchor was? Maybe they trip-hammered the bottom of the CTS perimeter wall, when they trip-hammered the pavement (sidewalk?)? I've had a curb broken when the adjacent pavement was removed.

SF Charlie
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[spsalso]

So in the April 2020 photo, I see a pretty radical dip in the pathway coming out from between the two planters, and going left.

In the June 2021, it appears to be much less of a dip.

I am basing this on the helpful color lines overlaid onto the photos.

I wonder why that is.


spsalso

 

[zebraso]

I may have missed it, has anyone suggested the directly that the April 2012 photo may have been taken to document slumping. The building manager has stated that near daily walk-arounds were done for the purpose of property safety. Let's give him a lot of credit for that much. He may have noticed the beginning of movement as early as April. What if we find out there were more photos of the same spot taken even earlier? I mean this is not a tourist photo that was handed to NIST when they requested them.

Edit: belaymylast 2020 not 2012

 

[dik]

This thread is approaching 400 replies. You might want to start Part 17.

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

-Dik

 

[FJBnomics]

Reference Fuchsia Arrows on SFC's Power Point Graphic.

As mentioned earlier, would failure at South Wall Under Planters actually cause the 'Catenary Stub Area' to initially move upward, until things let go? Basically the South Wall to Column K15 becomes a bigger lever arm load on the span between K15 and K13.1 for 2 weeks and 2 days?

Edit: Middle Span is 30 feet and much longer than adjacent spans, which begs the question, how in the world do you design a flat slab with same rebar everywhere and same slab thickness when spans are not equal? Looks like it was designed in that 30 foot span would deflect more than adjacent spans, thus providing 40 years worth of unbalanced stress on pool deck? Not to mention the various column sizes and layouts?

On the next two images below, are we seeing evidence of slab drop at South Wall? Note Dark base board like area at wall/patio deck joint?

 

[SFCharlie]

Good Questions!
please see the following from Josh (building integrity):
1. Engineering Failures Found in the Champlain Towers South Drawings - Surfside Collapse
(Toward the end, where he talks about the changes in the area of the valet parking planters)

2. Zeroing in on the Initiation of the Surfside Collapse

3. 16 Days Before the Surfside Collapse - The Warning Signs Were There

Thanks.


SF Charlie
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[Sym P. le]

Elevation survey 08/07/2020

 

[FJBnomics]

Thanks SFCharlie for those BI links. I watched parts of them again, and this time it sunk in better, I think.....

I added where roughly Column 76 is, and lowest point near that column from Survey Posted. This clearly shows why Column 76 was such a good drain path for deck, after perhaps the nearby cracks were epoxy injected.

Edit: Also shows 9.52 low spot on parking deck side of gate from pool deck, with 9.5 drain elevation nearby.

Edit2: I do find it interesting that Building Integrity has NOT linked the Pool Exhaust Fan Exhaust venting East along South Wall, as a probably contributor of accelerated corrosion and slab shear in that area of south wall. I did notice in BI's links provided by SFC, that on one of the original drawings he uses, the exhaust fan originally exited on the West Site of Planter Wall at South Wall, and not East as built.

 

[SFCharlie]

Here is my first attempt to visualize the elevations.
As you can see, trying to draw contours was a disaster.

SF Charlie
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[FJBnomics]

The deck had much less variations in height 8/7/20 than say April 2020 Photo or June 2021 Photo. Per survey only about a 3/10 variation form high to low. Which is pretty good considering the two layers of pavers and sand fill. Problem is Finished Deck heights do NOT necessarily tell the exact story of the structural deck.

 

[SFCharlie]

Next Try, Feedback Please

SF Charlie
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[FJBnomics]

It helps me visualize the elevation differences well, much like a contour map would. In some ways it is better to me.

Edit I assume the elevations in the planters is at bottom of planter, which indicates that there may be a layer or concrete forming bottom of planters that is on top of structural slab. Or some sort of elevated base inside the planter, perhaps part of a drain system, or maybe just the dirt level in planters.... Duh!!

 

[zebraso]

If I did not know any different it looks like they were directing water from the entire pool deck to go through the gate and onto the non water proofed parking deck. Then maybe it was supposed to go to the street. I mean assume a drenching rain down pour in which the drains are overwhelmed. Is this the proper way to do it?

 

[SFCharlie]

Moribato may have had his faults, but he did identify failure to provide slope in the pool deck as a major issue and indicated fixing it in his proposal.

SF Charlie
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[Jeff Ostroff]

photo I saw of the pool and deck taken 36 hours before the collapse clearly shows a proper slope to me so I was always puzzled by Morabito's comment that there was no slope.

 

[zebraso]

Structural deck vs pavers (maybe). This was just pointed out.

 

[zebraso]

What is the effect of directing water to a central point where the structural deck underneath is not sloped? Is that a "special" problem?