Champlain Towers South (Surfside, FL) Collapse Investigation

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Жыл бұрын

In the early morning of June 24, 2021, the eastern half of the twelve-story Champlain Towers South Condominium collapsed, killing ninety-eight residents of the forty-year-old building in Surfside, Florida. WJE was retained by attorneys representing the condominium association to determine the cause of the collapse and provide litigation support.
Our scope of work included a review of design and construction records, videos, and photographs taken before, during, and after the collapse; site inspections at the Champlain Towers South collapse site and NIST primary evidence facility; testing of construction materials and subsurface conditions (in coordination with the involved parties); review of relevant codes and standards; and structural analyses. Our investigation found that the flat plate slab supporting the pool deck above an underground garage was under-designed, with significant structural distress apparent before the collapse.
In this webinar, WJE structural engineers Matthew Fadden and Gary Klein detail WJE’s investigation and findings, including our collapse theory.

Пікірлер: 26

@chesshead3943 3 ай бұрын

Great video, thanks!

@chevypreps6417 11 ай бұрын

This is a very depressing story. This collapse was completely preventable. People should not be murdered by their home. I would be very nervous if I lived in the sister building a few blocks away.

@Lethgar_Smith Жыл бұрын

I am concerned about the lack of security video evidence. To date the only video released is the one we've all seen and the only reason we see that is because the condo tower from which it came released it directly to the press. Champlain Towers' own security video should be available because the portion of the building where the office is located and more than likely the location of the recording devices, did not initially collapse and there is no reason why they would not be retrieved before the building was demolished. At the very least someone should offer an explanation of what happened to each and every video recording that captured the collapse. Did the condo tower on the other side of Champlain not have security cameras? I dont understand why no one questions the lack of video evidence and just accepts that the one we see is all there is. That doesnt make sense and it defies logic. I say this because I have worked in building security for more than 20 years and I know about security camera systems. I have worked in everything from beachside condo towers to 50 story office buildings. There is tons of video footage of this collapse. I guarantee it.

@DrgnTmrSirGawain 11 ай бұрын

I agree. I question this too.

@lookforitcx 11 ай бұрын

Such a good point. I agree. I know Jeff Ostrof who produced some brilliant videos investigating this collapse, said he was banging the tables and asking for that very footage. There were cameras all over even on the property and pool deck. But I also heard/ read somewhere that the footage was destroyed in the security room and wasn't backed up online. The power also went out when it collapsed and cut off all the cameras. The harddrive was supposedly destroyed in the demolition of the standing portion of the building. They were not allowed to go inside and retrieve it before the demo for safety reasons. It's hard to know what to believe.

@maudessen573 10 ай бұрын

The security cams were not on the cloud…they wrote to a hard drive. At the June 2023 public meeting, NIST stated they have recovered several dozen hard drives and are examining them forensically. So far they have not identified the security cam drive. From what I have been able to learn, no one rescued the alarm system control unit before the implosion either. You have to remember that first responders were desperately trying to locate survivors before an incoming hurricane. The standing part of the building was moving every day…there were times it was so unstable that the rescuers had to leave the site for their own safety.

@Lethgar_Smith 10 ай бұрын

@@maudessen573 Thanks for the update. My frustration stems from the fact that the portion of the building which contained the entrance lobby and presumably any office or room where the camera hard drives would likely be located was the portion that was manually taken down. It is frustrating to know that the evidence we are looking for was possibly right there and I assume no one was entering the portion that was still standing after it was evacuated.

@maudessen573 10 ай бұрын

@@Lethgar_Smith Since we don’t have access to all the info NIST has, it’s hard to say how much of the lobby was left standing when the building collapsed. That section back beyond the mail room is probably where the DVR was kept, and I am not sure if that area fell down into the lower level or stayed up at ground level. We can’t go by Miami-Herald infographics. Security Guard Shamoka Furman was at the security desk by the valet window, making calls to residents, when the building collapsed. She was in total darkness and dense clouds of dust, so I doubt she would have been able to see what happened behind the security desk. Shamoka attempted to exit through the valet window, as the electric doors wouldn’t open. She ended up exiting the lobby to what was left of the pool deck, where she climbed down to the ruined garage and rescued several residents on her way to the street. So Shamoka never went anywhere near where the hard drive was likely to have been, and can’t tell us what was standing and what was not standing. As I said, it’s hard to know what was still on ground level.

@Herlongian Жыл бұрын

The under-designed pool deck was not waterproof. This allowed water in. The rebar rusted and the concrete slowly started to dissolve. You can see the wet areas on the deck photos. Faulty repair and faulty repair design.

@guruofendtimes819 9 ай бұрын

alot more also.

@hgbugalou 4 ай бұрын

Why arent more comments pointing out the pool deck columns were under designed since day 1? That is the smoking gun to me and should have been identified during initial construction. Someone cut corners back then or is completely incompetent.

@patswfc Жыл бұрын

Did the pool deck slab also act as a strut, propping the top edge of the basement retaining walls? If so, once a significant portion of this slab failed in punching, struct action would have been removed and horizontal loads from lateral earth pressures on the basement wall could then act on the columns.

@guruofendtimes819 9 ай бұрын

yep acted like a diaphragm eventhough I doubt it was designed for the load.

@TheLoneWolfling Жыл бұрын

I know this is almost immaterial to the investigation; the part that confuses me is why it failed in the middle of the night. In a progressive failure like this I tend to have a mental model of strength gradually decreasing over time, with noisy actual demanded loads, and failure occurring when actual load exceeds the strength. But because the strength decrease is slow compared to the timescales over which the actual loads are noisy, you tend to see failures near locally-high loads (in the temporal sense, not spacial.). But in this case... as you mentioned, it's the middle of the night and all is quiet. You've pretty much got your baseline load and that's it. No live load to speak of. Why did it fail at 1:10 AM and not, say, 7PM the previous evening when there presumably would have been people (and hence additional load, and worse, live load) on the pool deck? Was there rain that evening? How much of a temperature swing was there?

@DrgnTmrSirGawain 11 ай бұрын

there was a strong rain, there was sudden additional loads imposed on roof deck (I vaguely remember hearing some equipment was being installed in the roof deck), could have also been suddenly windy (increased lateral load from a specific vulnerable direction), yes temperature difference between sunny day and wet windy night, all important factors. Also more people at night. I believe the planters got clogged and full of water, that weight caused beam under planter to fail, that created a whole in pool deck (per witness account of a whole in pool deck area), then the slabs failed and pulled the columns inward in direction of void center, then column failure at parking level and pool deck level (under that wing) cause the sudden collapse of the whole set of columns at each column location, with them the slabs.

@maudessen573 10 ай бұрын

@@DrgnTmrSirGawainThe roofers were installing new anchors for window washing. The City of Surfside building inspector was up on the roof inspecting the work that afternoon, and said that there was no abnormal loading up there. The roofers did have to pull off the job that afternoon on account of rain. Also…the sounds of failure were occurring as early as 11 PM, when Chani Nir returned home to 111 from babysitting. I have never found a witness who claims to have heard “banging sounds” prior to that time, and don’t know if Shamoka Furman could hear those sounds in the lobby. So, until NIST reveals the results of their witness interviews, we don’t actually know the earliest time when people started hearing the rebar fail, but we do know it was in the process of failing by 11 PM, and we also know Chani’s mom and brother heard it when they got home at about 12:30..

@aw2031zap 4 ай бұрын

Florida is hot. Night causes thermal contraction. Thermal contraction is additional load on the horizontal system.

@DrgnTmrSirGawain 11 ай бұрын

Most interesting to me has been the still obscure history of the genesis and prescription of the “40-year Recertification" requirement. Who approved, who adopted, and who influenced (if it was) the official creation and handling of such new, broad and very important document for the present (back then) and future of the real estate market and its "health". I say this because it might have been redacted and sent to city officials as "the requirement" or something that seems to be the sole requirement between notice of completion and 40 years after, therefore possibly influencing in opposite effort or mindset to the original preventative mindset or effort with which "recertifications" should be handled by associations, public in general, attorneys, professionals, etc. (assuming this preventative mindset is aligned and is a good example of responsibility: to "advance our nation's quality of life and protect the public's health, safety and welfare". If 40 years is not enough to make sure buildings don't collapse (and it wasn't enough back then since it all came from a building that had collapsed after 40 years) then why was the policy or prevention bar set at 40 years? who benefitted from that number, and who really set 40 as THE number. Thanks!

@maudessen573 10 ай бұрын

Miami-Dade and Broward Counties followed by the State of Florida adopted 40 years based on the 1974 DEA building collapse at the age of 49 years, which was caused in great part by excessive corrosion frequently found in Florida. 40 was intended to be conservative enough to prevent a similar recurrence. They were focused on corrosion rather than improper design. The engineer who developed the recertification program was John Pistorius.

@keithpeacock9282 10 ай бұрын

When buildings are that close to the salt water, It must be Mandated that they use STAINLESS STEEL REBAR which won't rust like steel rebar will. it doesn't cost that much more and they were getting ready to spend over 10,000,000. on concrete repairs. stainless steel rebar would have been way cheaper.

@guruofendtimes819 9 ай бұрын

lowest bidder

@hgbugalou 4 ай бұрын

They found little chloride inclusion in the concrete as shown here and they also said rebar corrision wasn't a major contributor to the failure. It's proximity to the ocean had nothing to do with it. More over, stainless rebar was not used in common construction back when this building was built.

@camheady235 5 күн бұрын

Yes, 100% right. And they increased the "cover" to protect the steel from salt, but that reduced the resistance to shear, says me: BrickSaverLLC.