Miami Beach, Champlain Towers South apartment building collapse, Part 10 79

[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


SF Charlie
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[SFCharlie]

parking garage attached to a high rise condo building collapsed in 2010 in Hackensack, NJ

Several photos in slide show
photos-from-inside-hackensack-nj-parking-garage-collapse


SF Charlie
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[spsalso]

So I see that Breiterman signed off on this job, in his official capacity. And he said he did all the necessary inspections and everything was great.

I do wonder why.

Say, didn't he design the structure (with hints, of course, from the architect)? So, while he might have been good at seeing where the plans weren't followed (but apparently was not), he would naturally endorse someone following his plans even if they were full of errors. "They built it just like I designed!"

That said, it does seem that every building he ever worked on should be found and inspected, as to problems. Since he was an Official PE (I believe), I think the cost of that should be borne by a special assessment from his PE peers in Florida, who allowed him to become licensed.

The inspections should be done by out-of-state PE's (and maybe some helpers) that have NO ties to Florida.


Moving on to the City, I would assume, perhaps wrongly, that the City hired their own engineer to at least spend 3-4 hours going over the plans. Let's not forget who was paying Breiterman, and to whom he thus owed allegiance. This engineer, being paid by the City, would owe the City that allegiance.

Or. Did someone in the Building Department consider themselves competent to go over the plans? Seems a bit much. I have no problem with a City guy doing this for a bed/bath addition. But this one was BIG.

spsalso

 

[SFCharlie]

NIST search results 'surfside'
I hadn't been aware of this:
B-Roll Video Reel - Champlain Tower NIST investigation

SF Charlie
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[SFCharlie]

NIST researchers at Champlain Towers
Do I see cold joints top, bottom, and side of the column? Is this the standard way for slab and column to be cast?
Now I can see it better, what I though were smooth failures at the sides turned out to be rebar, sorry.


SF Charlie
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[Spartan5]

NIST search results 'surfside'
I hadn't been aware of this:
B-Roll Video Reel - Champlain Tower NIST investigation

I posted it to open thread 7. But it apparently got lost in noise over the structural defects people were observing in the real estate listings for different units.

 

[Santos81]

Soo...

It would be very difficult to assess anything those experts suggest for one simple reason.

The plans provided by Surfside do not depict the as-built structure.

 

[MaudSTL]

the except below based upon witness testimony and design short falls was very interesting to me concerning lateral movements of building.

This is the first time I had read this card table/lateral movement statement attributed to Gabe Nir. In all the previous statements he talked about feeling the rumbling and the building shaking…not mentioning anything like this new statement. I wonder if the M-H interviewed him again. Has anyone seen any other source with a statement like this?

Also, they missed Chani Nir’s statement that the knocking sounds were happening when she got home at 11 PM. And we still don’t know if Shomoka Furman heard the knocking sounds from the lobby. So they are starting their witness timeline with Gabe and Sara’s arrival at 12:30.

 

[Sym P. le]

Is this the standard way for slab and column to be cast?

Yes. The photo shows a column extended through two levels, the lower to the left and the upper to the right. The rebar from the lower level is crimped so that it laps up to the inside of the upper level column rebar (the photo can be misleading seeming to to show the lower level rebar terminating below the upper level rebar). One can also infer from the photo that the upper level column rebar was stood in place prior to the casting of the floor slab.

The slab rebar in your photo is extraordinary for its paucity.

I'm curious as to what the inspector is pointing too but the photo does not lend much to positive speculation on that.

 

[SFCharlie]

Articles mentioning "swaying"
'Tragedy beyond tragedy': Champlain Towers South was a catastrophe in slow motion

Raysa Rodriguez was sleeping in her room on the ninth floor when she awoke disoriented. The building was swaying "like a sheet of paper." She ran into the hallway to find that it had been impaled from floor to ceiling by a concrete pillar; the doors of the elevators were shorn off, exposing the shafts.

Family Escape From Florida Condo Collapse: ‘Run, Quick!’
There is detail in this that I haven't seen before, but it paraphrased... ...originally from the Washington Post.

SF Charlie
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[Demented]

@Sym P. Le

You can also noticed the burnt ends, which shouldn't be. The gas axe shouldn't have been anywhere near that.





Maybe I read the wrong article, but are there really people now trying to say the building had too much rebar and that's the issue?

 

[gonefishing2]

@Demented, One wonders why the gas axe was needed, if the rebars were detailed on shop drawings by fabrications shop, cut and bent to exact lengths, and tagged or marked according to shop drawings as to where they go. Of course, you have to be willing and able to read and understand the shop drawings during assembly?

Edit: Perhaps gas axe used to adjust for as-building errors? Or using wrong rebar in wrong location? Or Who needs Shop Drawings, just build on job site on the fly?

 

[SFCharlie]

... the building had too much rebar and that's the issue?

It may have said that, but I understood it to mean the column was to narrow for the required rebar. (also, the NIST photo seems to show all the rebar very close to the bottom of the slab. Yes, that's where the tension is, but was there sufficient cover?)

SF Charlie
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[Vance Wiley]

The general rules for engineering work seem to be that all engineers are expected to perform their work to the "standard of care" at the time and location of the design of the project in question. The code adopted in that area at the time defines the minimum requirements, and additional requirements generally used by engineers at the time and location could set the "standard of care".
So we need to look at other buildings designed by other engineers for Surfside and Miami in 1980 to define that "standard of care". If there is a preponderance of projects with better corrosion and chloride protection (more concrete cover, epoxy coated rebar, dense and modified concrete) and this project is found not to have that protection, then the engineer has not met the "standard of care" threshold.
Add to that that many courts find that if the project served as intended for 10 years then something else must have developed in the interim. Like bad environment and no maintenance - think coastal exposure.
Serious design errors do not make it past construction - think FIU Pedestrian Bridge. Champlain lasted probably 3 dozen (12 floors x 3 zones ?) removals of slab forming and shoring while the concrete was not fully developed strength wise and 40 years of occupancy and exposure.
We should note it is failures like CTS and close examinations like this forum and by government agencies that may move the bar as to "standard of care" and/or code requirements.
Thanks,

 

[Demented]

@All About Money

A few things I've seen out in the wild.

1) Shop fabricated cage needed to be cut to allow for lateral rebar. It's getting encased in concrete, no one will notice
2) Short on rebar. Use offs to make up difference, weld cut ends together per super. Nothing detailed on drawings, often forgotten. Or "we'll do it tomorrow first thing" only to come in to concrete encasing the work you never finished.
3) Length call-outs as multiples of diameter is not as easily understood by the laborers or detailers as we'd all like to assume.

 

[MarkBoB2]

After reading the Miami Herald article “Surfside tower was flawed from day one” found by SFCharlie, it sure sounds like the CTS building was poorly designed and poorly constructed and was ready to collapse at any moment. But the article does hedge a bit, stating that “Although the trigger is still unknown, there is a growing consensus that the Champlain Towers’ progressive collapse was initiated by a first-floor slab failure”.

It is interesting that the article quotes the recognized structural expert, Allyn Kilsheimer, as stating that the Champlain Towers North building, which has the same design plans and construction team that the CTS had, “did not raise any red flags after his initial inspection.” In fact, he states further: “I would let my kids and grandkids stay in this building,” Kilsheimer told reporters on July 12. “And, if I find something that would not let me do that, the first thing I would do is tell you, ‘you have to get out of here.’ We have not found anything that concerns me at all on the exposed and visible conditions or on the testing we’ve done so far.” Later, Kilsheimer told reporters he had subsequently looked at the building designs and structural drawings but stood by his assessment that it is safe for occupancy.

Now, I believe this article, which echoes many of the comments made here on this Eng Tips thread. And what I have been trying to do is to find the trigger for this collapse. My latest effort has involved trying to find evidence in the debris pile to support what was found in the TikTok video. I started with the following figure, which shows that the objects in the TikTok video were seen near the M11.1 column at the base of the ramp. This region is close to column 76 and column 28, which lie on either side of the driveway just a few feet beyond column M11.1.

In the next figure, column 76 and column 28 can be seen on the pool deck after the collapse. By noting that column M11.1 lies in a line with column K11.1 which also can be seen in the figure, one can establish that the TikTok objects should be located approximately within the red ellipse in this figure. Note that under the umbrellas in this figure one can distinguish multiple rolls of tarpaper, which were suspected by some to be vaguely visible in the TikTok video.

In the next photo, which shows the region of interest from a different angle, I have zoomed in on this region of interest. Sure enough, one can see the same objects that were found in the TikTok video still located on the basement floor under only one layer of debris from the roof of the east wing that collapsed last. One can easily distinguish the top of an air conditioner and the bottom part of the same air conditioner behind it. One can also see two hexagonal weights on rods, one on each side of the air conditioner, along with pipes, a planter, and a long metal bar attached to a cement column that were seen in the TikTok video.

One can see these same TikTok objects in the following photo taken after the west wing of the building was demolished. These objects can be seen more easily by zooming in further on the ellipse, which can be done using the PowerPoint document provided with this post. Again, it is easy to distinguish an air conditioner under the pile along with two hexagonal weights on rods and pipes seen in the TikTok video. In addition, things seen in this photo that could not be seen in the previous photo include tarpaper rolls within the field of view of the TikTok video along with a car in parking space 26 and another white car in either parking space 28 or on the driveway behind the TikTok objects.

These two photos not only show the same objects seen in the TikTok video, but also the same objects that were seen on the small debris pile left at the end of the ramp for two days when everything else in the parking basement was removed. It is believed that the recovery crew leaving this small debris pile standing for two days was an indication of its importance as supported by red cones connected by red tape left on the ramp and by seeing five Miami Dade firefighters witness every shovelful of debris removed by the crane operator when clearing this region.

I will not go into the implications of these videos at this time. I suspect it will be controversial enough to establish that the main object in these photos is an air conditioner that appears to have dropped from the roof onto the beam between column 27 and column M11.1. This object appears to have sheared the horizontal beam from column 27, thereby eliminating horizontal support from column 27, and initiating the collapse of the pool deck and then of the building itself, just as was seen in the CCTV surveillance video. This appears to be the trigger that caused the collapse. All of this would have been aided by the design errors and construction deficiencies discussed in the Miami Herald article.

The objects in these photos should be viewable much more easily than those in any of the previous photos I have shown. If anyone still persists in saying that there is nothing in these photos and that these objects are all a figment of my imagination, then they are taking a gamble that the final report for this collapse will contain evidence of these objects and maybe even cite them as the trigger for the collapse. In this case deniers of this evidence and those who ridicule it will look foolish indeed.

 

[Demented]

@Markbob2

Are you calling the fire fighters sitting at the table roofing rolls?
I swear I've got a higher resolution photo from one of the FR teams somewhere that shows the fire fighters taking break time there in the mid-day heat.

 

[Vance Wiley]

Sounds strangely familiar to the statement by Denny Pate (EOR) less than three hours before 6 people died at FIU.
He has reset the clock, so to speak, from 40 years ago to today, and should several of todays engineers find a problem, he may find he did not meet the "standard of care" for investigating a building in 2021. He clearly did not have anything to do with conditions created 40 years ago, but he has promised everyone in the building that they are safe today. If anything bad should happen, he has bought it. I doubt he has that much insurance.

 

[gonefishing2]

@Vance Wiley

What we read in Miami Herald investigation based upon their design based calculations, may be giving the As-Built Condition too much credit, since nothing seen so far in public information indicates the building was built as well as the suspect design.

Edit: The garage floor slab appears to have fared well from collapse and heavy construction vehicle traffic during cleanup.

 

[Nukeman948]

. . . these objects are all a figment of my imagination, . . .

Obviously, I am more than willing to risk looking foolish, however I am not trying to prove any one theory over any others.

The plans provided by Surfside do not depict the as-built structure.

And the only way to confirm how it was actually built (and remodeled, maintained) is to wait for the investigations findings.
They will show where the flaws were and what likely led to the collapse, and those facts will be hard for some people here to swallow.

 

[IEGeezer]

I have attempted to find a trigger by assuming that the drains in the planters were clogged and the planters had filled up with water. How much would this water have weighed? The full version of Acrobat has a measuring tool that can be used to estimate the dimensions of the planters and therefore the area. Based on a photo of the planters, I assumed the height of the planters was about 1 meter.

I assumed water so I used a density of 1, then converted back to pounds. Based on the photo below,

I estimated the additional weight of planters full of water due to the rain at about 85,000 lbs. The structural engineers will need to opine if this was enough weight to trigger the collapse, given the deteriorated state of the slab, the extra weight of the additional layers of tile and the poor initial design. Just a thought.

https://res.cloudinary.com/engineering-com/image/upload/v1625947773/tips/12_ugqkvz.jpg

https://res.cloudinary.com/engineer...26128572/tips/Untitled_drawing_h-1_bkjxsh.jpg