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

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dik

Structural
Apr 13, 2001
25,672
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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
 
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spsalso (Electrical) said:
From Mr. Porter's video, the proposed "initial" inspections (as required by potential new law, discussed) could be carried out by an architect. I wonder how Friedman would have approached this task if called upon to review CTS.

As far as design architects or even design engineers, Josh Porter, made it clear a pure designer is not qualified nor has the right experience and skill set to perform Milestone Structural Inspections and design Structural repairs. He even went on to say he specializes in the inspection and repair side, and does not feel qualified to design say a new 10 story building.

His point being, Milestone Structural inspections needs to be performed by a qualified engineer specialist, not a pure designer, and conversely.
 
From Florida Senate bill 1702:

(starting at line 195) "For phase one of the milestone inspection, a licensed architect or engineer authorized to practice in this state shall perform a visual examination...and provide a qualitative assessment of the structural conditions of the building"

(line 205) "If the architect or engineer finds no signs of structural distress...phase two of the inspection...is not required."

Mr. Friedman was an architect. He would have been permitted to do phase one of the milestone inspection of CTS. If he found no problems, there would be no need for a more in depth phase two. Since he was probably more familiar with the building than any other architect, it would make sense to choose him to do the job.

For that matter, it looks like Breiterman would also have been "on the list". Another good choice, since Surfside approved of him inspecting his own work, rather than finding someone else.

And we know how good a job Friedman and Breiterman did. I'm sure they would have kept on doing following work to that same standard.


spsalso
 
IanCA said:
1=Banging from 11 PM…

I just wanted to clarify that 11 PM is the earliest report of banging that we currently have, because that’s what time Chani Nir got home to 111. The banging may have begun before that time, but we have no statement to confirm what time it started. We don’t know, for example, what time Security Guard Shamoka Furman came on duty in the lobby, nor do we know if she was able to hear the banging too. If she was able to hear the banging, it might help us to know what time she began to hear it. If she heard it during her entire shift, then we ought to find out if the guard on duty in the previous shift also heard the banging, and, if so, what time they started hearing it,

I am scheduled to meet this coming week with Dr. Ganapati of FIU, who has joined the NIST team to work with witnesses, among other things. I will do my best to bring to her attention questions like these that would be helpful to get answered.

>>>>>Edit. I think another detail that would be good to know is which space the Vazquezes parked in. They arrived right after the loud crash at 1:10, and it would be good to know their likely line of sight as they walked to the elevator lobby.
 
MaudSTL said:
The banging may have begun before that time, but we have no statement to confirm what time it started.
Understood, thanks for clarifying.

MaudSTL said:
I am scheduled to meet this coming week with Dr. Ganapati of FIU, who has joined the NIST team to work with witnesses
Thanks for letting us know. I wish you the best for your meeting.

I'm still trying to find time to work on the collapse sequence narrative and joint details.

Suggestions welcome.​
 
Please also ask Dr. Ganapati how the inept rebar provision in Member 11 of the failed bridge was missed.
 
Thermobaric said:

I uploaded the link to the Witness Statement Timeline to NIST on their data portal back on 8/19/2021.

If the active sub-team working out a collapse theory right now feels confident in their theory, it would make sense to share it with NIST, even if you want to use screen names for professional reasons.
 


Becker, a law firm that represented the building’s condo association, said it would pay $31 million; Morabito Consultants, an engineering firm hired to inspect the building for its 40-year recertification process, said it would pay $16 million; and DeSimone Consulting Engineers, a structural engineering firm for another building nearby, said it would pay $8.55 million under the deal. Sale of the property will also be divided.
 
IanCA said:
I'm still trying to find time to work on the collapse sequence narrative and joint details.

In case it would help, here’s how the Miami Herald infographic House of Cards depicts the construction joints. Dr. Lehman would have reviewed this prior to publication, so it may have been acceptable to her from an engineering perspective.

6040F356-C782-4529-ADB3-66A40328000A_azav93.jpg
 
MaudSTL said:
I just wanted to clarify that 11 PM is the earliest report of banging that we currently have, because that’s what time Chani Nir got home to 111. The banging may have begun before that time, but we have no statement to confirm what time it started. We don’t know, for example, what time Security Guard Shamoka Furman came on duty in the lobby, nor do we know if she was able to hear the banging too. If she was able to hear the banging, it might help us to know what time she began to hear it. If she heard it during her entire shift, then we ought to find out if the guard on duty in the previous shift also heard the banging, and, if so, what time they started hearing it,

I am scheduled to meet this coming week with Dr. Ganapati of FIU, who has joined the NIST team to work with witnesses, among other things. I will do my best to bring to her attention questions like these that would be helpful to get answered.

>>>>>Edit. I think another detail that would be good to know is which space the Vazquezes parked in. They arrived right after the loud crash at 1:10, and it would be good to know their likely line of sight as they walked to the elevator lobby.

We all have a few questions for the suitcase lady from the Justin Willis story if she is ever found. What made her think the building could collapse at any moment?

I am also interested in how long the deck collapse lasted. Witness statements make it hard to tell if it was a single boom or it was a series of loud bangs and rumbling over 5-10 seconds, which would be my guess.
 
At the risk of being repetitive, here are the two Miami Herald article links:

1. Original story, headlined "The Herald built a computer model to explore how Surfside tower fell. Here’s what it showed" By Dawn E. Lehman and Sarah Blaskey Updated January 12, 2022 4:45 PM -- per Dawn Lehman, "... describes the timeline of the collapse that we used to support the modeling we did."

2. The follow up story, headlined "The last stand of Champlain Towers South. Computer model, witnesses reconstruct the tragedy" By Sarah Blaskey Updated January 21, 2022 2:31 PM -- per Dawn Lehman, "... the modeling approach and different scenarios that we evaluated."
 
MaudSTL said:
In case it would help, here’s how the Miami Herald infographic House of Cards depicts the construction joints.
Thanks MaudSTL, you prompted me to make another effort.

I think the Miami Herald infographic is slightly off because it appears to show the joint to the West as a straight line, but I think it actually steps about 2' - 3' further to the West, in the area south of column row 14 (South of the lobby area). This is based on photos that show the joint in the stamp-create aligned with the East face of the columns in row I as shown below:
gettyimages-1233652806-2048x2048-stampcrete-edge_copy_onayjk.png


But the joint in the structural deck appears to be further West than the West face of the columns in row I as shown below:
below-parking-deck-with-joints-v2_copy_xpqvfb.png


In order to predict where the joints were in the parking deck and pool deck I looked at the joint spacing in the garage floor slab, because the actual as-built positions can still be observed.

If the garage floor slab joints are overlaid on a drawing of the parking/pool deck they appear as shown below (with parking garage column positions emphasized):

joints-1-overlay-v2-crop_ejs1mi.png


The spacing of those joints can be aligned with features on the parking deck by mirroring the joints and shifting West as shown below:
New version showing regions, due to uncertainty.
joints-1-overlay-v4-notes-crop_nuwzv0.png



The point I am trying to establish is the probability that there was an intermediate construction joint beneath the planter running South to North close to columns on line K, in addition to the two shown on the Miami Herald House of cards infographic.


Suggestions welcome.​
 
Reverse_Bias said:
I am also interested in how long the deck collapse lasted. Witness statements make it hard to tell if it was a single boom or it was a series of loud bangs and rumbling over 5-10 seconds, which would be my guess.

All the witness statements I have ever read (Nirs, Furman, and Vasquezes) are clear about hearing the deck collapse as a single, very loud crash rather than a sequence of bangs and rumbling over time. The MH calls it “one loud cascade of concrete” in the article explaining the House of Cards infographic.
 
Sym P. le said:
…here are the two Miami Herald article links…

I think we still have to take the MH timeline with a grain of salt, at least until they reveal the witness statements they used as the basis for their timeline.

There are three areas where the MH timeline is at odds with contemporaneous, publicly available witness statements made in the days immediately following the CTS collapse.

The MH claims that banging was heard starting around 1 AM, yet Chani Nir stated at the time that she could hear banging when she got home to 111 at ~11 PM.

Sara Nir, who clearly and repeatedly stated at the time that the “first collapse” (that she thought was a wall collapsing above 111) occurred at 1:10 AM. Yet the MH states that crash occurred at 1:14, which is the time that Sara said she went to the lobby. This means there was a five minute interval between the “first collapse” at 1:10 AM and the deck collapse, which was the “second collapse” at ~1:15 AM.

The MH also claims that witnesses were able to describe the area of the deck collapse. In this article the MH states,”Witnesses described the collapsed region as initiating from the southern perimeter wall and extending to the northern edge of the pool deck, where a video shows the debris from the deck collapse at Column Line 9.1 near the southern edge of the 12-story tower. (That portion of the building was covered with debris after the tower fell and therefore the exact boundary is unknown.)”, which is not accurate. There is not one publicly available witness statement identifying the extent of the deck collapse. Sara Nir, Gabe Nir, and Nico Vazquez only saw the deck collapse after the fact, from the lobby and the porte cochere. The late Cassondra Stratton only saw the deck collapse after the fact from 410, having been awakened by the building shaking. Mike Stratton says she told him she could see the pool (meaning pool deck) had fallen into a sinkhole. Floridians seem to use the words “pool,” “pool deck,” and “parking deck” interchangeably, so the witness statements can be confusing, especially when you take into account that many witnesses are speaking English as a second language.
 
I updated the image in my 12 Mar 22 10:19 post above to regions for possible joints rather than specific locations.

Suggestions welcome.​
 

A grain of salt or with a liberal dose? I see now that their modeling assumes the slab abutting the south perimeter wall rather than resting upon it. Of course, if that were the case, a catastrophy would be in the making if the connecting rebar corroded. I just can't see this as supported by the photographic evidence nor with standard construction practices.

The media industry pumps out content because that's what it does but I'm dismayed with the lack of quality found in too much of it.
 
This has nothing to do with engineering, but it is worth knowing that Miami-Dade has succeeded in maintaining its long reputation for corruption. 23 hours of first responder audio from two channels have been deleted, and the County failed multiple times to inform FOIA requesters of the deletion. The deletion includes audio related to the failed attempt to rescue the late Valeria Barth of 204, who died in the garage fire. From USA Today, Miami-Dade deleted critical audio files from Surfside collapse search-and-rescue effort.
 
Sym P. le said:
The media industry pumps out content because that's what it does but I'm dismayed with the lack of quality found in too much of it.

As far as the Timeline: CTS Collapse Witness Statement is concerned, I get frustrated that the media creates flawed narratives that become accepted as factual. People go through the NYT and MH infographics and think they are looking at proven facts, when what they are really looking at is a combination of fact, fiction, and conjecture.
 
I visited the Champlain towers condo collapse site on Saturday and shot extensive amounts of video and photographs and as I had mentioned on one of my videos back in February about how they added some shoring poles to the Champlain towers north building in the garage and some unit owners closets, now they have added shoring poles on the patios of several units on the building here are some photographs I took on Saturday.

DSC_8863_foltla.jpg


DSC_8851_i7bvsu.jpg


20220319_153637_gb7rha.jpg
 
Jeff Ostroff (Electrical) said:
shoring poles to the Champlain towers north building in the garage and some unit owners closets, now they have added shoring poles on the patios

This does not inspire much confidence. Those poles are not there to support the balconies IMO. I bet they finally got around to testing the concrete used throughout. This should be a big deal.
 
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