Miami Beach, Champlain Towers South apartment building collapse, Part 09 139

[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

SF Charlie
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[Spartan5]

This system has a number of weaknesses so one can imagine several plausible scenarios where a 10 ft long section of this parapet wall could have fallen off the roof and crashed through the plaza deck. In fact you could probably argue that this is more likely to have occurred than a spontaneous collapse of the plaza even granting that the plaza was poorly designed and maintained.

This one can’t imagine a plausible scenario where the roof just falls off. Has anyone put one forth even?

But say we do have a spontaneous collapse of the roof where a whole ten foot (wide? long? square?) section just falls off the building. How is that more likely to have occurred than the plaza failure?

The nature of the abnormal punching failures in the plaza slab indicates something was severely amiss there. Doesn’t it? That’s all in plain view. No imagination necessary.

That roof section that just fell of(weighing how many tons???) would have hit the ground below at around 70 mph. It would not have sounded like knocking noises, or construction, or even a “wall collapse.” Or any noises from above for that matter. It would have sounded like a bomb going off outside. And would have looked the same to anyone peering out the windows after they heard it.

It would not be a disturbance that you stroll casually over to security to say, “Do you hear the sound? It doesn't make sense in the middle of the night, early morning, people doing construction.”.

People on the ground floor next to where that would have fallen would not have reported it as being something that could be ignored:

Nir described the noises as sounding like “construction knocks” and was disturbed that they were being made at such a late hour, with her son and daughter fast asleep in nearby rooms.

“I thought someone had decided to renovate their apartment in the middle of the night,” she said. “At first, I ignored it. But a few minutes later I became upset about it and left the apartment.”

Show me what the failure looks like. I want to see the where and how this big ol’ chunk of roof departs the building. If there’s a plausible scenario for that, sketch it up for me. Let’s figure out what the mass and impact of that would have been when it hit the ground.

 

[JDATL]

There was an earlier discussion regarding which government entity was in control of the site. Apparently Miami-Dade is.

In the video, it's clear that Miami-Dade is preventing Surfside from starting their own investigation.

So Miami-Dade declared the site a crime scene. Maybe all disaster sites are classified a crime scene when there's no apparent reason for the disaster. Maybe there is EVIDENCE of a crime. Maybe it's a cover-up attempt (I highly doubt this one). What other reasons would Miami-Dade prevent one of the preeminent experts on building collapse ( Allyn Kilsheimer ) from examining the site?



[URL unfurl="true"]https://miami.cbslocal.com/2021/07/27/surfside-full-forensic-investigation-condo-collapse-site/[/url]

 

[Optical98]

Spartan5

I was thinking about that 'knocking sound' she mentioned as well. What about pipes? Sometimes pipes can make knocking sounds. Did they start that Generator perhaps? Maybe more units were without power than the one mentioned.

Did the building have propane or gas hook-ups? There was a Kitchen off from the Rec room, did it have a gas stove?

Just some thoughts...

 

[BKNJ]

Show me what the failure looks like. I want to see the where and how this big ol’ chunk of roof departs the building. If there’s a plausible scenario for that, sketch it up for me. Let’s figure out what the mass and impact of that would have been when it hit the ground.

Let's suppose that whatever was done on the roof causes a portion of the slab to fail over the x11 stack. There is some shear puncture at the outside columns and the slab hinges down somewhat... maybe 20 or 30 degrees. Nobody is in PH-A at that hour to see it, but now a couple lose pieces (~15lbs) of the parapet or large crumbs of the slab where it broke fall and either hit the balcony immediately below of ricochet down and hit the pool deck, making "construction noises" that reverberate through the building. At some point, a large section of parapet (>15 feet) lets go, takes out the balcony railing below and falls 12 stories to the pool deck starting its failure.

That's kinda what I see as a remote-remote possibility. I'd love to hear how this couldn't ever-ever happen.

I'm not a member of "team roof" or any of the more outlandish conspiracy theories, including AC units, cars crashing or boats on the roof. I suspect the authorities have evidence that negates these possibilities because if it existed, something would have leaked to the media by now.

BKNJ

 

[Nukeman948]

I was thinking about that 'knocking sound' she mentioned as well. What about pipes? Sometimes pipes can make knocking sounds. Did they start that Generator perhaps? Maybe more units were without power than the one mentioned.

Did the building have propane or gas hook-ups? There was a Kitchen off from the Rec room, did it have a gas stove?

The generator only supplied emergency power for one elevator, fire alarms and fire pump, security, water supply and emergency lighting for locations like the stairwells, lobby and exit paths. No sump pumps except for the elevator shaft seem to be in the original plans neither from normal power nor emergency power. Hmmm...

The building was designed to have all electric HVAC, water heating, cooking appliances and laundry equipment and didn't need gas. (still may have had gas but I have not seen any evidence or need for it)

 

[Seppe]

Like Spartan5, I'd like to see some quantitative basis from the "roof-first" crowd.

How do we go from a rebar potentially nicked by a hammer-drill to Marvel Universe level destruction, and how do you get the timeline to actually make sense? Was it because, as one poster suggested, the crew was actually doing work under the cover of darkness to skirt permitting and inspection mandates being enforced during the day? If so, did they base jump to safety as the penthouse and roof collapsed from beneath their feet?

Was it the pallet of rolls of tar paper (are we creatively counting up to 120 rolls yet, or are we still at 49)? If it's the pallet loading, what about the live loading on all of the PH/roof slab area that surrounded the localized area covered by a pallet? Was it zero, and if so, how does that cumulative effect compare to the design roof live load applied across the entire roof surface and the internal forces that would result?

And one of my favorite angles so far: the poster who keeps invoking some sort of Morabito collusion, where the structural Morabito guy was in cahoots with a Morabito concrete repair/restoration guy.

Help me to understand the roof-first theory through analysis, as opposed to sensationalized story-telling and rampant conjecture.

 

[Optical98]

Thank you Nukeman!

 

[SFCharlie]

I'm in the middle of a project. I downloaded the earliest copy of the CCTV file from YouTube. I'm copying the frames one by one. I'm having to register each frame, because whoever captured the security screen, was moving their (smartphone, camera, whatever) around as they captured it. In just the first 20 frames, I have been astonished at what I see. As many have agreed, a large portion of the roof is missing in the earliest frame that is legible (if you can apply that word to a picture). The next and most startling thing I see, is that the collapse does not happen as a single fall, but in stages. I'll attach the draft PowerPoint. If you would like the individual frames, I can provide that as well...

SF Charlie
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[arbitraria]

@Seppe - I think the Morabito collusion angle is conjecture based upon the concrete restoration company staff including one Phil Morabito; both companies having Florida & Maryland locations; I recall seeing somewhere that they've worked together before on similar projects but I could very well be mistaken. I know papa Morabito brought them on board to fulfill the concrete restoration portion of the project, in a seemingly familiar relationship (I'll go see if I can find a quote momentarily}.

It wouldn't be the first time various firms have handshake agreements to throw each other work, roll projects together to "make things easier" for the client. Some are fairly legitimate, others not so much. Judging by the somewhat-less-than-inspiring plans we've seen from them, the shadier persuasion is definitely within the realm of possibility. I don't see it as a conspiracy-level theory as much as questioning potentially dubious or even corrupt business practices.

 

[Vance Wiley]

I second that. We know any successful creation is not just an assembly of successful ideas. It must include the proper application of those singularly successful ideas and the vision to know when another good idea should be added.
Then it needs someone to step back a bit and look to see if the entire project as designed is even a good idea.
Forcing something to work is just not a good idea. Hoping that it will is even worse. I am not suggesting this building was designed on hope, just that there were parts missing that could have prevented the sudden and total (for the section not demo'd) collapse.
Please excuse the comment - it does not advance the quest for details in this case, but it could possibly benefit someone down the line.
Thanks,

 

[Debirlfan]

First, a question. According to preceding posts,it's not unknown for snowbirds to 'rent' their empty units to contractors who live in and renovate the unit during the off season. Is there any suggestion that any of this 'stealth' work was going on in the building? Might unauthorized work in a neighboring unit have caused the power outage in 508?

Could the PH parapet have been damaged by workers hauling materials for the roof construction over it, or by accidentally tapping it with a suspended crane load, etc? Not to the point of the entire parapet falling, but enough to crack some chunks of concrete, possibly even days earlier? Water seeps in, vibration from further work and perhaps even the elevator, and a few chunks fall. Say in the 50 to 100 pound range. It appears that anything falling from that area could have fallen into the planter below. If so, landing in the dirt and greenery could have muted the sound. Would the abrupt impact of 100-200 pounds of falling cement be enough to collapse the deck in that area if the deck was already overloaded and weakened?

I tend to believe that the failure was a result of a combination of questionable design, shoddy work (both initial and repair), corner cutting and work on the beach and building next door which may have further compromised the structure. But, I am open to the possibility that there may have been a straw that broke the camel's back on that particular night.

 

[Demented]

@Zebraso
Yup, nothing to see here.

@Nukeman948
As scary as that is, I do agree that this failed repair prevented further collapse.

@Arbitraria
That be the one, thanks. I was too focused on the beams that I missed the latter.
I brought up the anchor cable before, as it was called in the permit. Been trying to find more details on it because I suspected it was attached to the side of E2, which would mnore explain the tearout on that column we see. I do believe it was anchored somehow and it did put up a fight as it fell.

A ratchet strap however there raises some curious custions.
Even a bad building inspector would likely take issue with that. Why would this have not been noticed, said to be fixed, etc?
Secondly, could this ratchet strap have been used to tie off to a roof anchor and the cooling tower to perform the load test of a new anchor?
I'm trying to disprove roof first and this is one of the key areas that I feel would have needed to collapse to initiate the roof first toppling that we see with the dibris distribution that was present from day 1.

I'm mostly concerned with the weight of the new retrofit A/C on a modified steel temporary structure with a known to be poor full beam replacement, that had all sorts of weird shit done to avoid stressing the slab it was on, but every measure to not shore loads was taken here. On a water soaked roof too, with lesser quality concrete, and all that other work that was going on around and on it at the time. I feel the middle of the upper floors and sections of roof failed first at this location. It is possible that this was a result of the initial collapse, not the initiator. Don't get fooled, just have an open mind. There are many distinct and different collapses that happened over 10 minutes or so, possibly an entire day. It didn't just go down because a column went missing at the base. We know concrete gives us signs it's in trouble. Those signs are just hidden under latex lipstick that was slapped on this pig.


Edit: Oh, a ratchet strap, especially a 3" or 4" wide one most crews who transport heavy things have, can and will bend steel beams like that before they themselves yield. Done it plenty of times. Ratchet strapping something into place because of warped material when pie heating is not allowed. You'll cave steel in if you go a little too far.

 

[Santos81]

The next and most startling thing I see, is that the collapse does not happen as a single fall, but in stages.

Starts at the lower x11 stack, then the UPH hinges along the E-W interior at or just before the corridor showing the PH (12th floor) soffits proud to the camera, PH-11 balcony gives way and swings vertically to the east, striking the lower x12 units, where the columns supporting the massive eastern lobby level beam group fail, and so on.

A lot of motion not only in this area and direction, but towards and away from the camera as well.

 

[Red Corona]

The biggest problem for the 'roof first' theory (at least the variant of it that has something drop off the roof to start the plaza failure) for me remains the fact that no-one, especially 111, reported anything falling from the roof. If it had bounced off all the balconies on the way down then 611 would have noticed that. We know the plaza failed before the main building, and we know it failed somewhere in front of 111, if not first then certainly early on (from the TikTok video).

There are certainly lots of reasons to be suspicious of the roof work. It's even possible that the roof slab failed (we know it was water saturated in areas, particularly around the area that collapsed) and maybe even that the penthouse roof crushed the whole penthouse with nobody noticing, if it was empty. And it does seem too much of a coincidence. But I don't see a mechanism for that to result in plaza slab failure, which I think we all agree happened before the building column failure.

@SFCharlie, thanks for fetching the freeze frames. I am now somewhat more convinced that by the time of building collapse, the 13th floor is missing in the collapsed section. I've taken a grab of frame 3 from your set, where you can clearly (well, by the standards of the video) see the floor correlation, along with the Bing aerial shot for comparison.

You can clearly see the strip of paired non-balcony windows running up to the 12th floor balcony, and the 12th and 13th floor balcony parapets. But the 13th floor itself is missing (at least the front portion) in the collapse area. We don't know if that happened 5 seconds earlier or an hour earlier though. (Someone posted a few threads back that the alarm should go off if sprinkler lines are cut, but I think everything is serviced via the corridor, so if the slab is hinging and only the front part is dropped, they might well not be cut.)

 

[Murph 9000]

I think the Morabito collusion angle is conjecture based upon the concrete restoration company staff including one Phil Morabito; both companies having Florida & Maryland locations; I recall seeing somewhere that they've worked together before on similar projects but I could very well be mistaken.

MC was working out of CP&R's Florida address back in 2018. That doesn't prove any particular nefarious actions, per se, but the two companies are clearly closely associated.

http://web.archive.org/web/20181105052724/http://morabitoconsultants.com:80/contact/

They worked together on Dolphin Towers in 2015, getting an award for it:

Morabito Consultants, Inc. was an Outstanding Award Winner for Dolphin Towers Condominium – Remediation project in the 2015 NCSEA Annual Excellence in Structural Engineering Awards program (Category – Forensics/Renovation/Retrofit/Rehabilitation Structures under $20M).

https://www.structuremag.org/?p=10101

(article written by Frank Morabito, so it's a self advertorial, but has useful / interesting information).

A benign explanation for the relationship is that MC simply borrowed / rented some office space from CPR after a successful project, to expand their activity into Florida. And Phil Morabito may have just discovered a job opportunity due to the relationship. It doesn't have to be nefarious, and there's no specific evidence of wrongdoing. Companies do have a habit of continuing to work together after a successful project, which is all we can really say with much certainty.

I'm giving them the benefit of the doubt, in the absence of evidence.

 

[Murph 9000]

More background info on MC / Frank Morabito:

http://www.ncsea.com/downloads/file...ustaining Member Spotlights/Morabito_5.18.pdf

 

[Murph 9000]

You can clearly see the strip of paired non-balcony windows running up to the 12th floor balcony, and the 12th and 13th floor balcony parapets. But the 13th floor itself is missing (at least the front portion) in the collapse area.

I interpret that first frame of video as being after the central south facade has dropped roughly 1 story. Of the 5 lights in that section, I see the living rooms of 1010, 1011, 1210, and 1211; with the lit pair of non-balcony windows being the 1111 bedrooms. I also see the master bedrooms of the x12 stack hinged downwards to match the drop of the x11 living rooms. The lights are still on briefly because everything is basically just hinged down at that point, so the cabling has not yet been ripped apart.

For me, the PH floor and roof is there, not sure about the PH and roof parapet over the x11 units, and it's the basement or first floor that is missing at that point.

 

[Demented]

Caulk?
Who thought caulk crack repair on a slab was a good idea?

This would have been hidden from view and covered with pavers. Man was that parking deck full that night.

Also wonder where that .5" depth actually landed.

 

[Red Corona]

> with the lit pair of non-balcony windows being the 1111 bedrooms

I think it's quite clear that there isn't a parapet directly above that lit pair, and there is an unlit pair above? So that must be 1011 (lit) and 1111 (unlit) because there is a parapet going across above the unlit pair and not directly above the lit pair.

It's also actually an interesting question as to why we can't see the balconies on the collapse section. They are quite clear on the S part (that never collapses) and upper floors of E part, and you can clearly see the (what I'm saying is) 11-12 and 12-13 full width ones. Is it just because it's moving so the video artifacts obscure them?

 

[Murph 9000]

I think it's quite clear that there isn't a parapet directly above that lit pair, and there is an unlit pair above? So that must be 1011 (lit) and 1111 (unlit) because there is a parapet going across above the unlit pair and not directly above the lit pair.

1211 did not have a parapet, it had a full width balcony with railing. I think the balcony slab is there directly above the lit pair. To me, the continuous vertical line in the facade, between the x11 bedrooms, is interrupted directly above the lit pair, by the 1211 balcony.

The upper PH balcony has a parapet over the x11 stack.

Edit: Yes, I think the movement is blurring all of the x10 and x11 balconies. x12 has essentially not moved much at that point (on the east end, the master bedrooms on the west end of x12 are probably moving)