Miami Beach, Champlain Towers South apartment building collapse, Part 18 30

[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
Miami Beach, Champlain Towers South apartment building collapse, Part 14
Miami Beach, Champlain Towers South apartment building collapse, Part 15
Miami Beach, Champlain Towers South apartment building collapse, Part 16
Miami Beach, Champlain Towers South apartment building collapse, Part 17


SF Charlie
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[Sym P. le]

Geezer, demolition experts have this down to a science so I question whether there is anything more to learn. You are correct that the center portion of the building sifted northward as it collapsed. The movement of the ladder is interesting. When I looked into this movement some time ago, I watched a video of an inadvertent collapse where it was evident that a building could be drawn off its footprint by selective demolition. I believe if Line 9 was removed, a hinging effect about Line 8 would draw the building north. There are likely a number of nuances to this theme but as I inferred, a study of demolition science would shed light for us.

 

[SFCharlie]

Thanks, I think I see what you are getting at.
Is that a puff of dust, I see, just NE of the building about the sixth floor?


SF Charlie
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[IEGeezer]

Thanks, I think I see what you are getting at.

You're welcome.

 

[IEGeezer]

...hinging effect...

I'm familiar with the hinging effect. There's a hinging effect with the collapse of all columns. There's more to the theory than just the debris pile. All other things being equal, the most highly stressed structural element is the one that usually fails first.

 

[SFCharlie]

I realized I could measure the distance between the vertical "columns" of the facades on the video to see if it is possible to determine if the south facade fell down or back or both, Do we know if the original of the security footage is in public yet?

SF Charlie
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[SFCharlie]

Red line are early in the video, Yellow arrow indicate "column" fracturing an displacement to the side or back

 

[SFCharlie]

Zoomed in
Red line are early in the video, Yellow arrow indicate "column" fracturing an displacement to the side or back

SF Charlie
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[Reverse_Bias]

The Israeli team made a very detailed map of where every room ended up in the debris pile within a day or two of arriving on site. Has that map ever been made public?

 

[MaudSTL]

Daily Mail and Palm Beach Post to the rescue!

https://www.palmbeachpost.com/story...raeli-team-found-majority-victims/8021350002/

https://www.dailymail.co.uk/news/ar...harrowing-Florida-condo-rescue-operation.html

 

[SFCharlie]

One more try
Zoomed in

How did the lights stay on after the tower dropped two floors?

 

[SFCharlie]

I've signed up for NIST emails:
new-videos-available-ncst-champlain-towers-south-investigation

may-31-2023-champlain-towers-south-investigation-update-second-warehouse

SF Charlie
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[Sym P. le]

SFCharlie, That's a nice catch with the column buckling on the east portion. I think it's more visible in your previous anigif.

If I understand your second anigif, it holds the collapsing section constant. The image exhibits distortion on either side. It will be interesting if NIST can offer a rectified video for closer examination.

Further thoughts on east portion, the "H" Beam (BM33, 34, and 35) sits under the twisted east section. Does it rack the parkade columns that support it. The column that rests on BM35 slips off the beam and embeds itself into the garage slab. Is final "H" Beam location consistent with this theory?

Not to same scale as above

 

[Sym P. le]

A few more images of the "H" Beam

 

[SFCharlie]

If I understand your second anigif, it holds the collapsing section constant. The image exhibits distortion on either side. It will be interesting if NIST can offer a rectified video for closer examination.

Yes, I'm hoping for even the whole original video.
No I didn't mean to hold the center constant. Just getting two frames from the iPhone video aliened is a pain. Drawing the lines accurately taxes my unsteady hands... It still looks to me that the façade fell mostly straight down? But, How did the lights stay on after the tower dropped two floors?

SF Charlie
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[Sym P. le]

Garage View of "H" Beam

The beam runs beyond Line N (Column/Stall 15 and 26) further than the drawing above implies. In the photos, there is a large chunk of beam missing off the west end where is should run past the column.

P.S. Further review of the photos shows significant portions of the "H" Beam missing on both the east and west ends.

 

[Nukeman948]

But, How did the lights stay on after the tower dropped two floors?

Conduits are run with several 90° bends to get from the distribution panel to the individual breaker panels in each unit to limit splices. There is also plenty of slack in the wires in those conduits and panels. Since the ends of the wires are securely fastened at each end, as the building fell, it pulled those 90° bends straight and took up the slack. Two floors is about the limit for conduit runs of that length.

[sub]
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[Sym P. le]

The rebar for column N9.1 (Stall 26) (see images above) looks as though it is placed for a narrow rectangular column rather than the stout square column indicated on the plan and visible in the garage frame. Is this another case of displaced column rebar? At least one of the rebar appears to be shifted towards the center of the column. The quality of workmanship appears to be random.

Edit: Also the column as seen in the garage frame appears edge aligned with the north edge of BM33 rather than the south edge as per the drawing.

 

[SFCharlie]

Long road to healing: Surfside marks two years since devastating condo collapse
Read more at: [URL unfurl="true"]https://www.miamiherald.com/news/local/community/miami-dade/miami-beach/article276648851.html#storylink=cpy[/url]

Archive Link

 

[MaudSTL]

Here’s an archived version of the Miami Herald piece that anyone can access.

https://archive.ph/Iwp9u

 

[Jeff Ostroff]

Hey MaudSTL, I think we need you to start a timeline spreadsheet on the Titan submarine disaster from the Titanic expedition this week.