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Miami Beach, Champlain Towers South apartment building collapse, Part 17
12

Miami Beach, Champlain Towers South apartment building collapse, Part 17

Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric (Military))

Here is Structural Magazine Recommended details on offset columns. Spoiler alert, additional layer of rebar....

Not only that but the (additional) bottom bars are to be skewed to line up between offset columns. This allows for "constructability" by leaving the two standard layers orthogonal.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sorry, but we didn't have FEA back then, I was still working with a team to build a bad assed enough computer to run that "stuff?")


A computer design may have helped, but there were other more serious problems. Even the remedial work was not intended for a corossive environment. I've done 20 storey buildings using two cycle moment distribution... FEA is not a panacea.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (dik (Structural)23 May 22 17:06)

FEA is not a panacea.
Yes! Making and verifying the model is a task and a profession in itself.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

The red ovals have been IDed as elastomer, possibly from a previous repair.

@SFCharlie, you were right. I found another image that shows the lower feature, I had thought was a root or branch, from the side. It is clearly part of the stucco.



I still think the top of the long planter wall is tilted inwards towards the plants and that explains why the section above the horizontal crack doesn't have additional exposed cracks, because the inside edge is acting as a hinge and all the weight of the wall remains supported. There is no need to lift the weight of the wall, so if a root or branch was growing through the vertical crack it only has to tilt the top the the wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

I still think the top of the long planter wall is tilted inwards towards the plants

It’s hard to imagine a retaining wall tilting toward pressure as it fails. Moreover, sudden vertical vertical or horizontal retaining wall damage is very unlikely to be caused by root systems. In my experience, root system damage is slow and inexorable, causing retaining walls to bulge. If any tilting occurs, the retaining wall tends to tilt out from the top.

St. Louis has historic neighborhoods where many houses have brick or stone retaining walls by the sidewalk that are similar in height to the CTS planters. Those that are failing are most often bulging away from the plantings because the root systems apply slow pressure from behind them and push them forward toward the sidewalk until the bulge starts popping mortar. At that point the wall gets dug out and relaid. There is no vertical movement up or down.

I have also seen retaining walls with a sloping terrace above them tilt outward at the top and develop vertical cracks beside the section with the greatest tilt. This is caused by the pressure of the sloping terrace slowly moving downhill over time. In these cases, though, the tilting section does not drop vertically lower than the sections next to it, and the only part of the wall that might fracture horizontally would be at the sidewalk level.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

I still think the top of the long planter wall is tilted inwards towards the plants

Quote (MaudSTL)

tilt outward at the top and develop vertical cracks beside the section with the greatest tilt

Could we be being seeing torque induced crack due to offset columns with no skewed rebar to resist offset column torsion loading? This would also explain the diagonal crack running form K15 to K13.1 and perhaps onto Column 76?

Parking deck and planters create a tremendous torsion loading on K line under planters, due to unbalanced moments?

Edit: I have experienced exactly the retaining wall failure MaudSTL is describing. In my case a large tree is causing the push in one direction with vertical cracks on each side. Rotating wall outward from the base of wall. So sloping wall from base to top.

In my reading, unbalanced moments at offset columns creates uneven punch shear.

Also the crack under planters inside wall running E-W along parallel to south wall, is discussed by CE&FA. Where he states there is a dynamic loading in that area due to cars turning into parking spot then applying brakes. Note crack E-W just in front of car front tires along that wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric (Military))

with no skewed rebar to resist offset column torsion loading

The rotation moment has been there for 40 years. I think the question is why did it stop resisting in any plane after so long? The concrete turning to powder is not predicated much on the angle of the bars. It's interesting to note perceived design flaws. But it could be a red herring. If the deck is rotating down there centered at a column and it has proper stiffness wouldn't it go up at the other side?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Zebraso)

If the deck is rotating down there centered at a column and it has proper stiffness wouldn't it go up at the other side?

Yes, I think you are correct! Which leads us back to concrete degradation could have been problem, and any rebar issues were secondary?


Edit: The fact that building stood for 40 years, despite what appears to be design defects, correct and/or flawed repairs, deferred maintenance, remodeling adding weight, etc., indicates to me this failure is a systems problem and not just something that can be measured thru finite element analysis of what the potential 'as built's were.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Yes, likely. However the cracks may have been "accelerated" or encouraged by the moment. The the car weight helps too. Membrane ends there. Water under membrane into cracks?

Edit: meh. deck rotating down on planter column might explain the elongated crack in the planter box. Dang.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric (Military))

not just something that can be measured thru finite element analysis of what the potential 'as built's were

Yeah, you don't need FEA if you can tell the columns are already over loaded or lack margin without it. That was what the second drop beam was for right? So was an error in calculations made when the beam was removed? Cars were lighter back then?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
One of the recent videos shows gravel from the neighbor's sidewalk coming through the south wall. The rebar (that anchored the pool slab to the wall) is broken (not zipped) at the wall. To the east, a moderate distance away, short lengths of zipped rebar are visible. Farther east, where the building was brought down by controlled demolition, the rebar zipped full length.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie (Computer)(OP))

The rebar (that anchored the pool slab to the wall) is broken (not zipped) at the wall.

The Lehman FEA simulation included missing rebar in that location as well as corroded rebar. If I may quote from MH:
"The results: Corrosion, plus the removal of some connections between the pool deck and southern perimeter wall seemed to set the stage for progressive failure across the western half of the pool deck and into the tower through a vulnerability behind the elevator shaft, in the crook of the “L-shaped” building."

Read more at: https://www.miamiherald.com/news/special-reports/s...

That is the basis for the cracking and deflection graphics that have been posted here before. Now having included that info I think "seemed set the stage for" is a mouthful. According to MH it take 20 hours to run the full model on a super computer. I assume that FEA that is used in design method say in autodesk does not yield this type of data.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

If any tilting occurs, the retaining wall tends to tilt out from the top.
@MaudSTL Yes, I agree with all of your points, but I do see some other indications that suggest the displacement was not entirely vertical. I don't disagree that the deck was irregular and was showing signs that justified further investigation but I'm not sure the vertical displacement was as much as has been suggested.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Ring Cam footage and why Column L9.1 (along with K9.1) collapsed first, in simple terms.

To start, I chose an early frame and a later frame, aligning them with the credenza as a reference. Apparently, the camera has shifted slightly on the credenza though it remains in a very similar orientation w.r.t. the front line of the surface (the shift was 7 pixels left/right and 1 pixel up/down).


.
.
.
.
.
. Gratuitous spacing 'cause the two images don't sync well.
.
.
.
.
.

Consider the 2-D plane of the south face of the building. If Column L9.1 (along with K9.1) fails, the slab could hinge along the Line M north/south axis in turn pulling the two failed bays east. The walls remain vertical, while the floor slopes, forming a trapezoid. The credenza, on which the Ring Cam sits, presses against the walls and gets pushed around but remains a level platform for the camera. The credenza appears to be nudged east as triangulation shifts the floor in front of the camera.

If you consider the transverse orientation, a 2-D plane along Line L, similar trapezoidal action occurs. Given the cam footage, I presume the slab punches at Line 8, moving the hinge to Line 4 and pulling the two bays to the north. The credenza remains with its back pressed against the south wall in its original orientation so the camera appears to tilt forward as the south portion of the unit leads the descent.

As I said, in simple terms.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le (Mechanical)26 May 22 07:20)


I applaud your going back and relooking at the data that is available in the public domain and trying to piece together the clues that are there. There is a lot of information in what is available, that perhaps we have not pieced together yet.

It requires a lot of speculation and discussions about details available, and multiple looks from many angles form a diverse group of folks to find the truth and eliminate the red herrings.

For example, I have been thinking about Columns I14 and I14.1 coupled with K13.1, and Column 76, and South Wall damage. The more I look at the existing images, videos and available evidence, I can see things now that I could not see in the beginning.

For example, it looks like I14.1 was a traditional punch shear failure on all sides of column. However, looking at I14 it is clear the East side of column was torn away from column, while perhaps the other sides were more classic punch shear. Then looking at I13.1, it appears the slab tore away from the column on all sides.

Point is there is small details that points us to the direction/flow of the collapse. But no one has taken the time and effort to post all those pieces together that drives the whole story home clearly.

Perhaps because it is a major effort to piece together the complete picture of what is in our minds, especially with all the information that was available, and the fact that a lot of that information disappeared from public access, shortly after the collapse.

A better and more watchable version 2 of video O posted on thread 16

https://youtu.be/vxFsBEErI2U





RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (zebraso (Mechanical)25 May 22 17:34)

... I think "seemed set the stage for" is a mouthful.
Yes! Perhaps too much for them to chew?
We now know that the deck Slumped, weeks before. ( please see my post at Thread 16 17 May 22 15:57)
Also, looking at the photos in the CTS owner submission in their lawsuit against their neighbor, I see the discoloration of the joints in the pavers while construction was taking place next door. I associate this discoloration with Florida Black Algae similar to what I've seen at my parent's near Sarasota. It takes some time for the algae to establish itself, so long before the neighbor's construction? So, I assume the slumping and leaking and puddling has been going on for a long, long time?

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie (Computer)(OP))

I associate this discoloration with Florida Black Algae

It's funny. Only recently I had a passing thought about the stains. I was thinking about another condition in Florida. The tannins in the soil that are known for turning water ways and lakes dark/brown. I suspect they did not import the planter soil from very far away. Tannin containing water is often referred to as "tea-colored".

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (zebraso (Mechanical)26 May 22 18:28)

Tannin containing water is often referred to as "tea-colored".
Yes, another likely source.
The point I was trying to make is that the deck was sagging before the construction next door...

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
Is there a standard way to make a maintenance free, waterproof, concrete roof or deck?
Is there something that can be put between two layers of concrete, that will be waterproof and durable?

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I was wondering how they sealed the edge where it ends across the deck at the transition to the valet area. Did the do anything in particular about cracks the transverse that edge? Was it flashed somehow? Where is the work order?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

"Is there a standard way to make a maintenance free, waterproof, concrete roof or deck?
Is there something that can be put between two layers of concrete, that will be waterproof and durable?"

Coming to mind:

Tar. Maybe combined with roofing felt.

If you want to spend a few more bucks, stainless steel should work out. Or copper.


spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@SFCharlie Thank you for these observations.

Quote (SFCharlie)

One of the recent videos shows gravel from the neighbor's sidewalk coming through the south wall.
In this area, as far as I can tell, the deck above the wall and sheet pile sheared off from the top of the wall, or disintegrated, and collapsed into the basement.


Quote (SFCharlie)

The rebar (that anchored the pool slab to the wall) is broken (not zipped) at the wall.
Despite my previous flippant remarks on the topic, sorry about that, I think spsalso makes a valid point in his post in thread 15 at 12 Feb 22 15:51 as follow:

Quote (spsalso)

In the picture with the five red circles, I see holes. Not rebar. I don't see any rusty discoloration around the holes.
I think it's possible the rebar was pulled out.


Quote (SFCharlie)

To the east, a moderate distance away, short lengths of zipped rebar are visible. Farther east, where the building was brought down by controlled demolition, the rebar zipped full length.
I think the different regions you are describing correspond quite closely with those identified by Sym P. Le in thread 15 on 2 Feb 22 21:07

Quote (Sym P. le)

As I've further considered your previous images, I've realized that there are three failure modes along the southern edge and I propose the following:

Zone A: Slab is pulled north off the south perimeter wall
Zone B: A tab of the greater slab fractures along the edge as it is pulled simultaneously off the wall and laterally to the west as it follows zone A
Zone C: The slab breaks cleanly along the perimeter wall but does not pull off of the wall

Overall I think it means the strength of the concrete and rebar had changed quite significantly within a few feet.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I went looking for the original photos of the planter with cracks and found these recent documents I haven't seen mentioned before:

Dispose_of_Rubble_the_County_Deemed_as_Having_Less_Signficant_Evidentiary_Value

Relocation_of_Evidence_to_Additional_Primary_Evidence_Facility

NIST_to_Move-Rearrange_Evidence

County_to_Dispose_of_Rubble_Deemed_Less_Significant

It makes me wonder how the county is making that determination. Does anyone here have insight on that?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

It makes me wonder how the county is making that determination. Does anyone here have insight on that?

My take on the whole thing is that Miami-Dade County has had jurisdiction the whole way on this investigation, and the County called in NIST to take over the investigation. IMO, the County could have lead the investigation and forced NIST role to be secondary.

I am sure that the reason Surfside contributed to the Civil case settlement is that all sources of funds to civil case settlement, get a 'Get out of Jail Free' Card for joining in the settlement. In other words, immunity from Criminal prosecution.

Investigation only of interest to NIST now, as Miami-Dade County has settled the disputes. End of story as far as they are concerned.

NIST is not doing a collapse investigation, but rather a study of materials found after collapse and investigation of how to design better specifications and STANDARDS for Construction of Buildings.

This is a JOBS program for NIST and they Subcontractors, funded by Uncle SAM, at tax payers expense.

For example: Why only in US can hydrocracked petroleum be called 'Full Synthetic' Motor Oil? In Europe, Full Synthetic has to be derived from synthetic base stocks. Look up Exxon Mobile Law Suit against Quaker State. Hint: Quaker State Won....



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

"I am sure that the reason Surfside contributed to the Civil case settlement is that all sources of funds to civil case settlement, get a 'Get out of Jail Free' Card for joining in the settlement. In other words, immunity from Criminal prosecution."


I would surely like to hear where that concept comes from.

The closest match I can come up with is that if a damaged person accepts money from, say, Surfside, and says that that money covers appropriate damages, then it's pretty tough to say in a criminal trial that they ARE damaged. Since, by accepting the money, their damage has been erased. If the criminal charges are based on financial loss that the victim has said no longer applies (by accepting the money and signing the paper), yeah. I can see that.

But,as far as I can see, that does not at all apply to ALL criminal cases. If Surfside was accused of negligent manslaughter, paying off some victims does not shield them from prosecution. It MIGHT apply to a criminal charge of fraud.

An interesting point, for sure.

spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I believe 'Civil Compromise' is the correct legal term for where 'Certain' Criminal Cases can be settled with Money, when all parties agree, the DA can drop or reduce charges in certain criminal cases. It happens all the time in American.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

But the subject was that of using the fact of a civil case settlement to eliminate risk of a criminal trial. That was supposed to be the reason Seaside gave money. THAT is what I am curious.

What you are just now describing sounds like what happens when a corporation is found guilty in a criminal court. The corporation (meaning, in my opinion, the board members) do not go to jail. The corporation (meaning the stock holders) supplies money, instead.

For some reason, negligent homicide can get humans put into jail, but never corporations.

But I see no connection between this concept and getting off the hook by settling a civil trial.

"...the DA can drop or reduce charges in certain criminal cases." Yes, it does happen all the time. It's called prosecutorial discretion. Something else I'm not too impressed with.


spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

What I read was Surfside was not a defendant in the Litigation leading up to settlement, but they chose to join in and pay $2 Million Dollars. Why would they do that if they were not getting some benefit out of that???

Yes Politicians and Corporate Officers frequently skirt criminal prosecution by settling for an amount of money that satisfied the Government agencies or Class if class action litigation....

Unfortunately our Judicial System makes some decisions based on reasons other than the actual LAW...

My understanding is not all victims joined in Class Action, thus there is more risk out there, unless of course you reach a Judicial Settlement.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

"What I read was Surfside was not a defendant in the Litigation leading up to settlement, but they chose to join in and pay $2 Million Dollars. Why would they do that if they were not getting some benefit out of that???"

I think they did it because they were afraid they'd lose a lot more money if they were sued later. As you pointed out, they weren't defendants going in. That does NOT mean they wouldn't be at a later date.

What this does is preclude those same litigants from going after them later. It does not get them off the hook for any criminal charges. Nor does it get them off the hook for being sued by some entity that was not in the collection of litigants in THIS suit.

I believe that anyone who declined to join the class-action can still sue. But they will not have the benefit of the "group discount" for the legal fees. There is, of course, an efficiency of scale.

Also, the decision to put up the $2 million may have not been made by the city itself. The city may have had some kind of insurance to cover the cost, and the insurer "insisted" that it happen. Again, to preclude a larger amount later.


spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

In legal terms though, it sets precedent, or what each life is worth....

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

A life is either worth money, or it's not.

If it's not, then no amount works.

Someone can offer you $1 for your child's life. It means nothing. They can offer $100 million. It means nothing.

If it is worth money, you have to pick a number.

Time to negotiate.




spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

If homeowners and HOA knew about damage and cracks in 20116, why didn’t they sue then?

I just put out a video last night itemizing the latest massive $1.1 billion settlement from last Friday, and the judge approved it over the Memorial Day weekend. I sifted through the 181-page settlement and built a spreadsheet with the entire breakdown of every single company that was a defendant in the lawsuit, and over a dozen other entities who are non-party defendants, not named in the lawsuit, but could be named later, and I showed their logos and in the amount that they are paying.

If the settlement is accepted by the 4 plaintiff classes, then yes none of these entities admit guilt nor can they be sued later on. However, the judge is allowing people until July 18th if I remember correctly, to opt out of the class action which would in my opinion be very foolish.

This 1.1 billion dollar settlement came out of nowhere Friday and was even higher than the $977 million announced on May 11, this surprised many people plaintiffs including the judge and people would be foolish to not take this huge amount of money now.
Litigation would drag on five to 10 years and most of the money would just go to the lawyers anyway. One other issue facing the homeowners there in the condo is there is this very strange Florida law that says that once the HOA insurance policy is maxed out, which it is right now, any amounts awarded more than coverage in a lawsuit, would have to be spread out amongst the remaining owners who didn't take part in the class action. This could be devastating here you are a victim and you can end up paying money to your property lawsuit settlement.

I know everybody was pointing fingers at everybody else but in reality, everybody here is likely culpable including all of the homeowners who illegally put tiles out on their patios and I showed on my video a week ago how numerous people had tiles on their patios. Over at Champlain towers north, years ago they forced all of the owners to remove tiles from their patios and to just paint and seal.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff (Electrical)1 Jun 22 15:08
)


Jeff

Thank you for your time and efforts summarizing the massive 1.1 Billion Settlement agreement in your latest video. I like you don't understand why the Security Company threw in 517xxxx million dollars when they were NOT even a defendant. No way their risk was anywhere that high, and in reality, no way they did anything wrong in my take either.

Link to Video: https://www.youtube.com/watch?v=lXBtvov3DLg

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I've seen reports where some people are blaming the security company for not sounding the fire alarm since she was told by Sarah Nir to pull the fire alarm after she made the 911 call at about 1:17 or so, she made two 9-11 calls. The building collapsed at 1:22, four minutes later. Maybe not enough time to get everyone out, and how many would leave anyway from a fire alarm?

ALSO, supposedly speakers were put in everybody's units and tested two weeks before the collapse so that theoretically they should have been able to speak into the mic and tell everybody to get out of the building that was going to collapse.
So there's some Gray area there, and also there was another 911 call that came in at the same time that the security guard called 911. That call came from the fire alarm monitoring service whose employee told 911 that there was a fire alarm at Champlain towers.

And of course, there was speculation about that whether the fire alarm was audible, or whether or not it was a pressure alarm when the pool slab crashed through the sprinkler pipes and the loss of pressure triggers an alarm and that is usually not an audible alarm for whatever reason.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

that is interesting, that author, Greg Batista, was one of the CTS defendants who settled, his company G. Batista and Associates, is paying $1 million to settle.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)2 Jun 22 04:33)

The first book is being published.
I just ordered it on Amazon for like $7, so I look forward to publishing a review here soon...

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Jeff Ostroff, you’re right about the four minutes. But no one would have known that a collapsed deck would bring down a building. It would have taken seconds to minutes to recognize that something even worse than the deck failure was about to happen.

~1:15 AM Deck collapses
1:16:27 AM Shamoka Furman reports "A big explosion" "earthquake."
1:16:39 AM Central Alarm Control reports fire alarm.
1:17:49 AM Shamoka Furman reports "Earthquake." "Garage." "Something underground everything exploded down."
1:22 AM Building collapses

I have never had a building collapse around me, but I have been mugged twice (within two weeks of each other…yes, I had to overcome PTSD.) In my personal experience with physical assault, it takes more seconds than you would imagine to realize WTF is even going on. Once you realize what is happening, then the adrenaline kicks in and you start to react. There is zero logic to the reaction…it’s instinctive fight or flight, and very strong. Unless you run training simulations over and over again to build the muscle memory of a desired reaction, you don’t know what you will do under threat.

My theory is that Securitas failed to train their security guards when and how to evacuate the building. If they were also responsible for maintaining the alarm and security camera systems, that would have been another critical point of failure.

>>>>>Edit: I have read comments from alarm professionals who say that it is common for a system alert to wait two minutes before triggering a call to 911, in order to allow for human intervention to reduce false alarms. If this system was designed that way, it makes me wonder if the deck collapsed just before 1:15…maybe just before 1:14:39.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Yes and I also wonder why when the police first arrived we knew the strobes were on for the fire alarm at least on the back deck now I don't know if those came on after the comma but why there was still no audible if the light was on. And when central alarm called were they reporting the fact that the security guard had triggered the alarm, or was it the loss of pressure from the pool deck crashing through the pipes and triggering the low pressure alarm which I have heard is sometimes not an audible alarm just so many questions around all of this whole alarm issue.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

SF Charlie you should be done kindling the book by now, did it have anything interesting?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I sprung the $10 for the print edition. Either way, Amazon sets it up so it arrives on the release date, Jun 28.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

...it makes me wonder if the deck collapsed just before 1:15…maybe just before 1:14:39.

I have previously hinted that adjustments like this to the timeline are likely to happen, but I didn't see much reason to speculate at the time without more evidence. I have been hoping that the investigators will release information from the EPROM (erasable programmable read only memory) that they would have removed from the fire alarm panel.

What the EPROM does is it logs and stores information for all functions and conditions of the fire alarm control panel. They will be able to determine the exact time, type and sequence of the alarm inputs and outputs and have an understanding of everything it did before and after the collapse until the batteries failed or the wiring was damaged.

If workmen ever disconnected or disabled power or alarm input devices like smoke detectors or flow switches, or output notification devices like the modem that called the alarm monitoring company or horn/strobe devices, those things will be logged too. Workmen could prevent setting off false alarms but how they do it will be recorded and they will know if the alarm system was restored to a functioning condition when they were done.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

…adjustments like this to the timeline are likely to happen…

Agreed. This is why I continue to monitor all publicly available info, and also why I get frustrated with the Miami Herald for muddying the waters with bad data. It would certainly be helpful to see that log and find out more about the rules that were used (or were supposed to be used) to program that system.

I have to wonder if, after testing the emergency speakers in the units several months before the collapse, someone may have left the voice evacuation announcement system in test mode, which could account for the absence of audible evacuation announcements. Another question is whether the fire alarm pull switch in the lobby, which had acted up in 2020, had been properly repaired. We do not know if it was pulled after the deck collapsed.

The log could answer these questions and much more, of course. According to the Miami Herald, two survivors from the standing part of the building heard evacuation commands on the speaker within their units but not in the hallways: Alfredo Lopez (605) after 1:22 AM and Daniela Silva (408) closer to 1:30 AM. I don’t know if a rolling evacuation announcement (if that’s what these times imply) is normal design to allow higher floors to start evacuating sooner than lower floors. I haven’t included post-collapse observations in the Witness Statement Timeline spreadsheet, but I do monitor them.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

1. "muddying the waters with bad data"
2. "someone may have left the voice evacuation announcement system in test mode"
3. "two survivors from the standing part of the building heard evacuation commands on the speaker within their units but not in the hallways"

1. I sure understand the frustration with bad data. Myself and others explained why sprinkler pressure is not used to trigger a fire alarm but some people cling to their own beliefs.
2. Leaving any switch in "test mode" would activate a "system trouble" light on the annunciator panel and a logged event in the EPROM. It can't be ruled out but it's not likely and the investigators would know the answer.
3. Adding new speakers for each unit would require a lot of work pulling new wiring circuits and new audio amplifiers. Speculating here but, It would be easier if they used wireless speakers (using WIFI) for the new unit speakers. The wireless ones may have still worked even if the wires were damaged for the ones in the hallways.

I have never heard of a rolling evacuation being used but normally an alarm reported in one zone (one floor for CTS) would only call for an evacuation for that zone. An alarm in the basement level would only activate speaker/strobes in the basement level. If an alarm is later received for another zone/floor, the evacuation announcement for the new zone would also come later. The code when this was built didn't require speaker/strobes on the parking garage level except by the stairs and elevator because this level was considered outside of the occupied building for this type of construction. (this part of the code has been changed to require them now and that is why they were being added for the 40 year upgrades.) General practice is to evacuate the whole building if an alarm is not acknowledged at the panel within 10 minutes.

Do you know if the evacuation message was pre-recorded or was someone using the microphone?


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Do you know if the evacuation message was pre-recorded or was someone using the microphone?

Daniela Silva (408) said she was awakened at about 1:30 by the evacuation announcement, and that it was a very loud female voice. That would seem to imply that it was a recording, but the Miami Herald article where I read this did not specify this.

>>>>>Edit: Also, per the body cam video timestamps on the Witness Statement Timeline…Shamoka Furman was assisting Ileana Monteagudo out of the collapsed garage by 1:26 AM, and presented herself to assist the police on the street by 1:37 AM. She could not possibly have issued the evacuation commands, and she is the only person who could have used the system.

Quote:

Speculating here but, It would be easier if they used wireless speakers (using WIFI) for the new unit speakers

I wonder about this too. Considering that they only paid about $100k for this alarm system, the use of wifi would certainly contain costs. I wonder if code allows that, though. And wouldn’t the speakers still need power, meaning that they’d have to fish wires to them anyway?

>>>>Edit: Also…it may be that it was an existing wired communication system that was upgraded to new speakers and transmitters. In other words, they may have been able to leverage existing wiring.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

...the use of wifi would certainly contain costs. I wonder if code allows that, though.

Code compliant wireless fire alarm components have been around for a few years now for initiating devices. After checking a few of my sources it appears that wireless speakers and strobes are not approved yet.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The speakers in the individual units were working, as Champlain Towers completed a successful test of those speakers on June 8, just 2 weeks before the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Here’s a bombshell of an article from Feb. 21,2022: Life-Safety Lessons Learned From the Miami Condo Collapse, published in Security Sales & Integration, an industry publication.

The author, a forensic alarm specialist, obviously has the alarm system log. However, he doesn’t reveal exact times for specific records. The following helps to explain why Securitas kicked in over half of the billion dollar settlement. Here are some highlights I saw…you may find others when you read it.

  1. System Features. “Champlain Towers had contracted with an alarm contractor that replaced the existing building fire alarm system with a new voice evacuation fire alarm system. Among other things, it included common-area smoke detectors, manual pull stations, voice evacuation speakers inside each of the apartments and in the common areas throughout the premises, and a remote alarm annunciator located in proximity to the 24-hour guard station in the lobby.”
  2. System was partly or wholly downnot functioning as designed. “Preliminary forensic examination of the central station’s account history report reveals that prior to the building collapse, the fire alarm system was in trouble, and a supervisory condition existed. The underpinnings of what part(s) of the fire alarm system was not functioning correctly and why it had not been restored to a functional mode through performing service on the system is continuing forensically.” Which parts were downhad issues? How long was it downnot functioning properly? Was CTS notified their alarm system was downhad issues? Was the local Authority Having Jurisdiction notified that this building’s alarm system was downnot functioning properly?
  3. Lobby pull station was activated. “It appears that a manual fire alarm pull station in the lobby of the building was activated before the collapse.” Based on the Witness Statement Timeline, I think this is likely to have happened sometime between the deck collapse at ~1:15 AM and Central Alarm’s 911 call at 1:16:39 AM. It is my opinion that Shamoka is most likely to have pulled it, even though she has never stated this in interviews. Sara Nir, if she had pulled it, would have said so, as she many times stated that she told the security guard to pull it and never stated that she pulled it herself. Would this have triggered the Central Alarm 911 call? Assuming it worked, should it have triggered lobby level strobes and announcements, or all-building strobes and announcements?
  4. Manual calls to residents. “… the guard decided to try and call each of the 129 apartments to tell them to get out of the building.” Based on the timestamps of the series of four 911 calls I believe were made by Shamoka Furman, I think she started making those calls to residents after 1:17:49 AM. This means that there were only four minutes left to notify residents to evacuate before the building collapsed, not seven to 19 minutes as the author suggests.
  5. Training gap? “Moreover, a determination has not yet been made as to if the security guard who was stationed in the lobby in the early morning hours before the partial building collapse was trained in how to use the system’s onboard all-call voice evacuation feature that would have been heard inside each of the condominium units at Champlain Towers had it been utilized.” Why would Shamoka start manually calling residents if she had been trained on how to use the all-call voice evacuation system, assuming it was working? I have not found any statements from Shamoka that she tried to use this system feature and it did not work.
I plan to update the Witness Statement Timeline with the activation of the pull station. It already has phone calls with residents, but it is probably in the wrong place, so I will need to fix that.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I can't really see a supervisory condition being equated to "system is down". That would more likely be attributed to a "trouble" status. I guess it begs the question as to how much disfunction can exist before it is considered a problem needing immediate attention. I'm sure the supervisory condition event status is configurable also. It's hard to believe that the supervisor status is presented without more information about what caused it. Wouldn't that data also be logged? Or was it up to the management to study the problem and figure it out? Then of course the question is how long was this status logged before the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I think the author is keeping his cards close to his vest. I guess we’ll have to wait to get more info.

>>>>>Edit: I made some edits on the original post to reflect your comments.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

That's fine. I did not question your interpretation, because I can believe it was presented that way or at least left it that far open to interpretation. I should have read the article. "Part or wholly down" does not exclude any possibility, given the terms not being well defined. I seriously doubt they are that well defined anyway. The only thing I get out of it is that the term supervisory refers to the system's role in monitoring the various elements to maintain full function and that a supervisory alert is one that does not rise to the level of "trouble". It seems quite ambiguous to me and they probably overlap as in all trouble is supervisory but not all supervisory are trouble. I would bet that is how it is and it's arbitrary to the whims of the programmer. So then we need the documentation.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I too found the article yesterday while searching for CTS fire panel info, trying to get a model # for the equipment they had there.

Are you aware that the CTS building manager in 2017 had written to the town of surfside to say they were unhappy with the performance of the company that installed their fire panel in 2017, and wanted to talk to officials in the building department about it.

Last I saw they had a meeting scheduled in Jan, 2018 but never saw what it was about.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Yes, this letter was mentioned in the Miami Herald piece linked to previously. It also mentions that the lobby pull switch had a fault in 2020, and woke everybody up in the middle of the night. I guess that could answer the question of whether that switch controlled the lobby level or the entire building.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

From:

https://www.nfpa.org/News-and-Research/Publication...

Supervisory – A supervisory condition means there is an issue with a system, process, or equipment that is monitored by the fire alarm control unit (see supervision section). An example of this would be a sprinkler system valve being closed, this would show up as a supervisory signal on the control unit. Here is a blog discussing some of the places you may find a fire alarm control unit.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I have an alarm question. Let’s assume there’s a properly designed alarm system in a 13 story residential building. I presume the system is intended to maintain building security and to keep residents safe in the event of a fire. How would we expect that properly designed and installed system to behave when the building collapses instead of catching fire or being broken into? I guess I am asking what normal system behavior would be.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Found this on Securitas settlement. With deepest pockets, the worse outcome of potential jury trial and nuclear verdict compelled their insurers to participate. They distanced themselves from liability and asserted they did not install or maintain security or safety systems, fire alarms or intercoms. Here’s a link and snippet:
Link


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

BraunEHC, where did this document come from? I had not seen it posted anywhere before

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (BraunEHC)

Found this on Securitas settlement. With deepest pockets, the worse outcome of potential jury trial and nuclear verdict compelled their insurers to participate. They distanced themselves from liability and asserted they did not install or maintain security or safety systems, fire alarms or intercoms.

Clearly having the deepest pockets or largest Insurance Policy seems to be a 'negative' for companies in high profile litigation; especially with the LLC option. Quick and Easy to form a LLC, then put very little assets in the LLC, so less risk of loss. Perhaps LLC rents the office space and equipment from another LLC that the principles own. Thus for example, the structural PE limits his exposure and has a very limited less costly insurance policy to protect the LLC. Say a $16 Million Policy for an over 1 Billion Dollar Settlement. If LLC has to go belly up in process, and they just form another LLC and repeat the cycle.

Quote (MaudSTL)

I have an alarm question. Let’s assume there’s a properly designed alarm system in a 13 story residential building. I presume the system is intended to maintain building security and to keep residents safe in the event of a fire. How would we expect that properly designed and installed system to behave when the building collapses instead of catching fire or being broken into? I guess I am asking what normal system behavior would be.

Hopefully an expert will chime in, but my experience says if any Pull Station is manually pulled, the fire alarm should alert everybody in the building. Yes that is designed as a fire alarm, but that serves as great communication tool that there is an emergency in the building. I do not know how the Voice System worked, but I would think they have multiple ways to warn residents.

One being an automated response by Fire Alarm, like broken fire water line, Two being manual pull of any pull station in building, and third being the security person using the new voice system in all rooms. I would assume the voice system with stobes in each room, work on all forms of trip.

My take on supervisory event is perhaps, because of the false alarm in the lobby previously, they performed a supervisory event to say override the Lobby Pull Station setting off more than the lobby area alarms. I would expect that is a fire safety violation, but is bandaid to defeat false alarm problem in lobby?

Edit: Perhaps non emergency failure, like say one pull station or one strobe, thus that node is bypassed till fixed?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

...when the building collapses instead of catching fire or being broken into?
I guess I am asking what normal system behavior would be.

First of all, fire alarm and security systems will be two completely separate systems.

A security system may include cctv, card reader or keypad access, magnetically held or released security doors, hold up and panic buttons and any other security features the client may want.

A fire alarm system will have input devices like manual pull stations and automatic fire detection devices like smoke and/or heat detectors and sprinkler flow switches. The fire alarm control panel receives those inputs and determines the correct output based on its programing. Outputs would include things like audio/visual signals to alert occupants, call the fire department, send a signal to the elevator controller, release magnetically held fire doors and close fire dampers in air ducts.

If the building collapses those systems fail. Yes, that answer is a cop out, but even in a partial collapse, if the wiring shorts out and blows fuses in the control panel, it could render the whole system inoperable. We try to counter that issue by providing redundant circuit paths when possible but there are no guarantees.

So looking at what I believe happened at CTS, when the pool deck failed it broke some sprinkler pipes but the one flow switch for that floor was located in the north west corner of that floor so it still worked. It may have damaged the wires for the speakers at the east stairwell as the original drawings show the wires passed through the area that fell. If it was set up to sound the alarm for just that floor/zone*, those speakers may have failed because of the damaged wires, but the control panel was still able to call the monitoring company. All other floors had two flow switches, one in each stairwell, but when the main collapse happened it took out the fire pump and sprinkler supply so none of those flow switches had a chance to work.

*Often, alarms are set up to sound the alarm in one zone only for a set time period before sounding the alarm in the entire building unless the alarm is acknowledged at the panel to limit people becoming complacent from repeated alarms that don't affect them.

Speakers are used instead of horns when voice outputs are available and strobes are ADA compliant for hearing impaired but would not be required in an apartment unless needed on an individual basis.

Edit to add: A speaker system may give a horn sound for things like fires, a pre-recorded message could be played, or a microphone can be used to give details that are hard to program for in advance. But all of these speakers will be part of the fire alarm system.





Not an expert, but I did stay at a Holiday Inn once.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

NIST is pushing hard to meet their 2024 report completion date .....

MJCronin
Sr. Process Engineer

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The long investigation was never what bothered me. It's the fact that they are going to sit on all the evidence and findings until a conclusion is reached.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Nukeman948, thank you for your alarm system overview. That really helps my basic understanding. Naturally, I have another question. This one is about the typical nature of required human intervention.

In a multi-story residential building like CTS, does a fire alarm system typically rely on human intervention to activate recorded evacuation warnings? I can see from your description that the designer has to balance false alarms against catastrophic events. So I am imagining that in most cases they would expect a human to decide whether to evacuate the building and activate a switch to issue the recorded alert. If this is indeed the case, then that means that training an attendant like the security guard would be critical. And it also means that the attendant would be a weak link in executive function…for example, if the attendant were unable for some reason to activate the switch, then it would put all the residents at risk. If I am thinking about this correctly, would the system compensate for the attendant’s possible fallability with logic like, “If X happens and there is no human override within Y minutes, activate recorded evacuation announcement and strobes on all floors.”

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

From the NIST article:
"When a particular theory gains traction or popularity in the public, we may directly address it in our final report so that the public will understand why we did or did not believe that theory to be consistent with the available facts and evidence."
I'll be keeping an eye out for tar kettles

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Jeff Ostroff (Electrical)7 Jun 22 13:15
BraunEHC, where did this document come from? I had not seen it posted anywhere before[quote ]Found it on slipcase.com, here’s a link:
Link

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL )

In a multi-story residential building like CTS, does a fire alarm system typically rely on human intervention to activate recorded evacuation warnings?

No. A fire alarm system would never be allowed that depended on human intervention to sound the alarm.
Recorded voice messages would be a customer option that is rarely used. They simply give a voice alarm instead of a blaring horn sound. The last one I installed used miniature cassette tapes and only gave a very basic announcements. Something like "May I have your attention please, A fire has been reported on your floor. Please exit the area immediately."...repeating for an eternity.

As soon as the control panel determines that a fire condition exists from inputs from things like smoke detectors, heat detectors or water flow switches, it will sound the alarms/strobes for the affected zone/floor (either recorded voice or horn sounds) and call the fire department or a monitoring company. After a set time period without acknowledgement from an attendant, a general alarm for the whole building will sound, but the alarm continues in the affected zone in either case. Time delays (with some limits) are used to limit false alarms, especially with flow switches. There are no silent alarms and the monitoring company would not be called without an evacuation announcement or horns/strobes for the affected zone.

The panel will remain in an alarm state until all input devices are cleared and reset. Water flow, smoke and heat detectors may be reset from the panel as long as water flow, smoke or heat are no longer present. Manual pull stations must be reset with a key or sometimes they will have a glass rod that breaks when it is pulled that must be replaced.

If equipped with a microphone, the attendant may select to make announcements to certain zones/floors or to the entire building. While announcements are being given the horns will be silenced and strobes will continue to flash. (It is possible that someone attempted to use the microphone and silenced the speakers but failed to make an announcement.)

Yes, the security company should have trained its people on how the fire alarm system operates and how to use the microphone to make announcements for any kind of emergency that may affect the residents.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Nukeman948, thank you so much for your clarification on how alarm systems typically handle human intervention. I actually feel much better to know that systems don’t typically function in the way I had imagined.

From the article posted earlier, so far we only know that someone activated the lobby pull switch. But there may be other human actions that have not yet been revealed.

I wish we could get that log. I wonder if it is possible to FOIA a copy. The Miami Herald did get to see it, according to a statement in one of their articles…but it is unclear if they actually have a copy of it.Maybe it will come up at tomorrow’s NIST meeting.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)8 Jun 22 17:32)

Maybe it will come up at tomorrow’s NIST meeting.
I hadn't heard or seen anything on this?
Is there a video link?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
Did anyone register?

Quote:

Anyone wishing to attend this meeting via web conference must register by 5:00 p.m. Eastern Time, Tuesday, May 31, 2022, to attend. Please submit your full name, the organization you represent (if applicable), email address, and phone number to Peter Gale at

Peter.Gale@nist.gov.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I will be present for the first half at least.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
The slides for the 2:45 "Modeling" look very interesting.
(the links in my schedule above, are for the slide .pdfs)

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

NIST has calibrated the video cam at 87 Park in order to enhance the collapse video in relation to their failure hypotheses.

>>>>Edit: I think we can give up any hope of seeing CCTV video from the CTS cameras. Note how this video slide refers only to home and commercial video sources.



>>>>>Edit: This entire process will extend to 2024-5, and NIST will not want to reveal much of anything until they publish. They plan to make 3D animations of their final hypotheses available at that time, but I don’t think we can look for anything sooner unless there’s a public outcry demanding something. I think this gives KCE the opening to provide an earlier hypothesis…assuming Surfside doesn’t terminate their agreement.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The same insecurities as the NTSB? Is there a copy of the enhanced video available?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

Is there a copy of the enhanced video available?

Not so far.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I think the same set of slides refers to "recovered" video.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)9 Jun 22 16:23)

Some of the slide sets end up with something like "push your 'blue jeans' button and enable camera and mic"
Please ask for release of the "enhanced" video. Thanks!

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The verbatim did not mention anything but home and commercial. If they allow public questions, I plan to ask specifically about CTS CCTV.

>>>>Edit: I had no opportunity to ask a question.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)9 Jun 22 17:57)

The verbatim did not mention anything but home and commercial. If they allow public questions, I plan to ask specifically about CTS CCTV.

Yes! Thanks!

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL (Computer) 9 Jun 22 16:23)


From that slide, the original video frame is far superior to those available via the phone video of the computer monitor. The only significant enhancement would be to do a white balance which is implied by the checkerboard image.

Which download is the slide from? edit: found it.

They are far ahead of us on image quality.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)9 Jun 22 19:40)

Yeah, it is much better. Slide 13 in this deck.

source MDPD?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

From slide 10, the Tiktok image, it's now hard to consider the green stuff on the right side of the image as anything other than Nir's deck furniture (unit 111).





RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

In this deck, it shows that the custody of evidence was transferred in January 2022 from MDPD to NIST. It is not explicit about whether that evidence includes all video and audio recordings as well as all material from the collapse site. But as this deck also shows, MDPD continues to be involved in NIST activities. I have to say I don't really understand MDPD's interest, as it is beyond the scope of a PD to act in a scientific capacity.

https://www.nist.gov/system/files/documents/2022/0...

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

2
Using two NIST slide images, it's clear that the x11 stack drops with column lines K and L (I think L leads the way). The whole east wing of the building appears to twist grotesquely as the collapse is initiated.





RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Maud, it is not likely you would have been able to ask a question at the meeting anyway today.

In most commission meetings like this, the public is allowed 2 or 3 minutes for public commentary, which means you can't ask questions, it is commentary only and they won't answer any questions you ask.

But you can make a commentary like this: "The public is upset that no video has been released from over a dozen cameras at CTS. This could then get them looking into it, even if they say nothing."

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Jeff Ostroff...Yeah, you're right...the only person who spoke during the public question period was a guy from the ICC who had no question but made a statement in the ICC's behalf. The discussion in today's meeting was all amongst the presenters. I will ask to be added to the public question period next time. In the meantime, I will follow your suggestion when I communicate with Dr. Ganapati.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Watering the plants?

My question is did the deck slab drop to the step while the portion against the building drooped and spilled the deck contents over the edge, or the did the whole (private deck) slab drop? If BMA with slab is on the garage floor, surely there would be more debris, so I'm inclined to believe the spillage scenario.

The mystery of the missing column is that it is hiding behind the shrubbery left of the green oval.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The missing column M11.1 is on outside southernmost border of the exterior wall of the building inside the planter. The planters would likely land behind it on the floor of the garage from the tourist's point of view.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

27 is M9.1, the building perimeter column. M11.1, the missing column is under the square planter boxes, supporting the south end of the BMA.

But you made me double check. ;)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

An attempt at a collapse sequence, starting at the planter column, 75. The valet parking area and the pool deck each took their own course, the parking slab beating the pool area to the garage floor and taking the chunk out of the pool slab along the south wall. Along the building, the BMA's and slab steps offer additional rigidity to the slab and likely impeded the progress. It just remains to determine how much initial damage was done prior the main event. We now know that the Nir's deck furniture ended up in the garage with the deck collapse and prior to the building collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

An attempt at a collapse sequence
Thank you very much for taking the time to prepare your diagram. A couple of the images from the NIST reports encouraged me to post some additional thoughts on this and your diagram is helpful for helping to illustrate the issue for general discussion.

I believe that where the degradation of the concrete was most severe there was more dust created during the collapse. Please correct me if that is not a valid statement. If the collapse starts at column 75, location 1 on your diagram, there should be a lot of dust at that location before any more of the deck collapses, correct? If the collapse progresses outwards, as you show, to columns 2, then columns 3 the dust will also be expelled outwards towards the perimeter of the parking garage in all directions, from point 1 North. That means there should be dust present in the air to the south, which there is in the CCTV video from 87 Park and as reported in witness statements but there should also be dust visible to the north in Adriana Sarmiento's video, but the still image on slide 10 of the file CTS4_Ganapati_Saidi_NCSTAC June 2022.pptx looks even clearer than we have seen before, with virtually no dust present in the air.

On the other hand, if the most degraded concrete is at the southern property line wall and the collapse initiates there, most dust will be present at the south property line wall of the parking garage. When the remainder of the deck collapses, air is expelled generally from the center of the garage towards the perimeter in each direction. And we know a gust of air was reported by Adriana Sarmiento. Since there is little or no dust in the center, in this scenario, little or no dust is expelled north. But the dust at the southern property line wall would be expelled and in a way that corresponds with the available images and witness statements. Does anyone have an alternative explanation for the difference in the level of dust we see and was reported, between the South and the North of the garage?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Isn’t prevailing wind also a factor in dust cloud analysis?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

To say there was a sequence of events does not address a time frame. The deck collapse happened suddenly so the initial displacement of air from the garage did not contain dust. (My two cents)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Thinking out loud, for 1 cent’s worth. Powder can not be pushed up and out at South Wall, until slab creates opening at wall, based upon powder covering South Privacy Wall in photos. Thus it would seem, there has to be a break in slab near South wall with heavily chemically changed concrete. Next step has to be deflection of slab between North and South, where deck hits ground first, thus creating a ground zero point for origination of pressure wave of air exhausted North and South.

If powdered concrete is worse South of that dividing line, then powder exhaust is South and North gets mostly clean air exhaust.

Edit: I also find it troubling that 87 Park planted palm trees in gravel next to Champlain South Wall. See slide 11 NIST image, 12:55 collection of afditional evidence

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
Maybe the cracking in the pool equipment area was more important than we realized earlier on?
(Not that it fell, but that it showed us the strain (distance) at the south perimeter wall?)
Does anyone have a good photo of the pool equipment area, after the debris was removed?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

Does anyone have a good photo of the pool equipment area, after the debris was removed?

I think the pool chemicals were a very big contributing factor at South Wall, and remember the vent for the pool equipment room was ducted up and into area adjacent to planter between Pool Deck and parking deck. In a photo posted somewhere, I saw that the vent fan area was surrounded by block walls and was completely open on top. Whatever type of vent cap that was attached to the duct work coming thru the 19"x19" hole in structural slab, was inside a larger blocked wall area adjacent to planter.

I would imagine it had some sort of vent cap, which would force fumes to blow downward and outward and around vent cap, inside that area. So this part of structural slab, and those block walls were bathed in pool chemical exhaust 24/7 for 40 years. Then throw in rainy days to wash the exhaust down into structural slab, as vent fan should have been running 24/7.

Edit, mid deck drop could hit garage floor first as it pulled slab away from wall in one of the zones at south wall, and North end of slab at building. Either way, it appears we have continental divide as far as powdered concrete venting.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Back on Sept 24 I posted my video where I had 100 or so close-up high-resolution images that I showed on the video. Here are 3 of those images so you can zoom into them.

[br]
[br]

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Jeff Ostroff (Electrical)10 Jun 22 18:36)

Back on Sept 24 I posted my video where I had 100 or so close-up high-resolution images that I showed on the video. Here are 3 of those images so you can zoom into them.
Thank you very much Jeff.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The pool room exhaust does not need a vent cap that would "blow downward and outward". We had someone claiming to be an HVAC guy posting on here at one time. I'll bet he knows of a better type of vent cap.



https://www.labconco.com/articles/zero-pressure-we...


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Perhaps an expert, could explain how you vent the pool chemicals to atmosphere adjacent to planters and a pool/parking deck without affecting the plants and humans in the area, while also preventing rain from entering duct work, with no visible vent stack, etc. in 1979 residential construction. From the plans it appeared to me there was a side exhaust thru block wall towards pool deck. Perhaps the missing top over that area was due to work being performed on the pool exhaust system.

Other ventilation fans required maintenance, so perhaps the pool ventilation system had failed years before, and there was no exhaust of pool chemicals, thus all the corrosion in that area?

Edit: Further they had a Covered Area in that corner of patio deck, near original pool chemical ventilation fan/exhaust. Looking more likely that a supervisory event might have turned off the exhaust fan or it had not been working for years, as very unlikely those chemicals were vented next to covered patio deck area???

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

Isn’t prevailing wind also a factor in dust cloud analysis?
I agree that is a valid question. Thanks for asking.

I went back to check again the wind data on weatherUnderground.com and WeatherSpark.com, but the sample rate is only once per hour. I went looking for a better source and found ncei.noaa.gov (National Centres for Environmental Information formerly the National Climate Data Center) Link [Currently unavailable]. Which revealed that the Automated Surface Observing System (ASOS) captures 5 minute and 1 minute data at ~860 stations across the contiguous US summarized here: UCAR ASOS. I found that Iowa State University have a well designed interface to accessing that date here: http://mesonet.agron.iastate.edu/request/download.... Also described here: IAState ASOS. Here's a snap shot of the information I entered:


MIA = Miami International
OPF = Miami / Opa Locka
WHWO = Hollywood - North Perry (not FPY = Perry)
Confirmed here:
FAA ASOS KHWO
and here:
Iowa State Mesonet - ASOS

Here is the 5 minute data for 1AM to 2AM for the three nearest stations:
station,valid,drct,sped
MIA,2021-06-24 01:00,40.00,5.75
HWO,2021-06-24 01:00,80.00,5.75
OPF,2021-06-24 01:00,70.00,4.60
HWO,2021-06-24 01:05,80.00,5.75
OPF,2021-06-24 01:05,50.00,4.60
MIA,2021-06-24 01:05,40.00,8.05
OPF,2021-06-24 01:10,60.00,4.60
HWO,2021-06-24 01:10,80.00,5.75
MIA,2021-06-24 01:10,60.00,5.75
MIA,2021-06-24 01:15,60.00,5.75
OPF,2021-06-24 01:15,80.00,5.75
HWO,2021-06-24 01:15,90.00,9.20
MIA,2021-06-24 01:20,60.00,8.05
HWO,2021-06-24 01:20,80.00,5.75
OPF,2021-06-24 01:20,100.00,4.60
OPF,2021-06-24 01:25,110.00,5.75
MIA,2021-06-24 01:25,50.00,5.75
HWO,2021-06-24 01:25,80.00,4.60

MIA,2021-06-24 01:30,60.00,5.75
OPF,2021-06-24 01:30,110.00,5.75
HWO,2021-06-24 01:30,80.00,4.60
MIA,2021-06-24 01:35,90.00,5.75
HWO,2021-06-24 01:35,80.00,5.75
OPF,2021-06-24 01:35,110.00,4.60
MIA,2021-06-24 01:40,50.00,8.05
HWO,2021-06-24 01:40,80.00,5.75
OPF,2021-06-24 01:40,100.00,5.75
OPF,2021-06-24 01:45,100.00,5.75
HWO,2021-06-24 01:45,80.00,4.60
MIA,2021-06-24 01:45,40.00,4.60
HWO,2021-06-24 01:50,80.00,2.30
OPF,2021-06-24 01:50,90.00,4.60
MIA,2021-06-24 01:50,60.00,4.60
MIA,2021-06-24 01:53,60.00,3.45
OPF,2021-06-24 01:53,100.00,6.90
HWO,2021-06-24 01:53,0.00,0.00
MIA,2021-06-24 01:55,50.00,4.60
HWO,2021-06-24 01:55,0.00,0.00
OPF,2021-06-24 01:55,90.00,5.75

I take this to mean that the wind was a light ~6mph breeze from the East (6.13mph at 78.8deg - North by East averaged across the three stations between 1:15 and 1:25AM). I think this agrees with the drift of the dust seen in the CCTV video from 87 Park when the north portion of the building collapses.

Even when the wind is blowing from the North (which it rarely does) the garage entrance is shielded by the adjacent properties and it's low elevation. There probably is some pressure difference between the North and South but I don't think it is significant in this case. There is airflow normally from the garage entrance out though the ventilation fans, but again I think that is less than significant compared to the volume and speed at which air was expelled when the deck collapsed. From your timeline, MaudSTL, we know the gust of wind from the garage was reported by Adriana Sarmiento, which I take to mean the air flow associated with the deck collapse event was remarkable relative to the general atmospheric conditions at the time.

Does that answer your question?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

The deck collapse happened suddenly so the initial displacement of air from the garage did not contain dust.

Thank you Sym P. le, I appreciate your response. I would like to share the image below to illustrate the dust I am thinking about.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

Powder can not be pushed up and out at South Wall, until slab creates opening at wall, based upon powder covering South Privacy Wall in photos. Thus it would seem, there has to be a break in slab near South wall with heavily chemically changed concrete.

Thanks for clarifying that point thermobaric.

Quote (thermobaric)

If powdered concrete is worse South of that dividing line, then powder exhaust is South and North gets mostly clean air exhaust.

I completely agree.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

So this part of structural slab, and those block walls were bathed in pool chemical exhaust 24/7 for 40 years. Then throw in rainy days to wash the exhaust down into structural slab, as vent fan should have been running 24/7.

Exactly. But even after leaving the vent and surrounding block work, the exhaust fumes were then blown through the adjacent plants, which have a very high specific surface area. This is why they collect far more salt from the prevailing wind than any wall or structural element occupying a similar volume.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

Looking more likely that a supervisory event might have turned off the exhaust fan...

LOL. Supervisory event? What are you talking about? You mean like from the fire alarm panel? That's not how any of this works.

Fire alarms supervise their wiring circuits to verify that continuity is maintained. We also use supervisory devices to verify that things like shut-off valves on the sprinkler system are not tampered with and the control panel for the fire pump has voltage. A "supervisory event" implies that wires or devices got disconnected or a valve was tampered with. There were no connections from this fire alarm system to that exhaust fan. A fire alarm system should never be wired in a manner that could interfere with the normal operation of any other buildings systems. If a fire alarm relay was wired to control this fan it would be so that if it lost power it would revert to normal operation of the fan.

In a fire event, most AHU fans will be stopped and fire dampers closed to prevent them from spreading fire through their ducts. Exhaust fans may be started by the fire alarm system to evacuate smoke from some parts of a building but it is above my pay grade to determine which fans that might be. I have wired supply fans to start from a fire alarm system to pressurize stairwells with fresh air so that occupants have a safe egress path. It would not make any sense to shut down any of the exhaust fans in this parking deck for a fire event or any other reason. Fresh air enters via the ramp and smoke or fumes (car exhaust and pool room) are expelled by exhaust fans. The only exits were through the lobby, to the pool deck and out the parking deck ramp, therefore, operation of the exhaust fans should have been a maintenance priority. We all know maintenance was sometimes lacking here but if you have any evidence that fans were not working for years, feel free to post it.

Perhaps the pool chemicals evaporate slowly enough and are diluted enough by the fans airflow that they are not as hazardous as you seem to believe they are. We dilute these chemicals with dihydrogen monoxide to make them safe enough for our kids to swim in them and with air to expel their fumes to the atmosphere.

Move along, nothing to see here.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

I would like to share the image below to illustrate the dust I am thinking about.

Just speculating but high local humidity from vegetation and pool equipment room fan may have caused condensation to form on that column causing the dust to stick there more than the other ones.

Move along, nothing to see here.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@MaudSTL following on from my earlier comment: "volume and speed at which air was expelled when the deck collapsed".
I did a quick calculation and I suspect the airspeed associated with deck collapse and exhaust through the garage entrance could have been as high as 200mph.

All figures approximate
Area of deck that collapsed: 9,287 sqft
Reduction in height: 5ft
Reduction in volume: 46,436 cuft.

Area of exhaust: 144 sqft.
Based on a width of 22' 6" and posted clearance height of 6' 5".

If the deck collapsed in one second the airspeed necessary to force 46 thousand cubic feet of air through an area of 144 square feet could be as high as 321 ft/sec or 219 mph. Assuming the air is incompressible.
I appreciate that not all of the air expelled passed through the garage entrance, as soon as gaps open in the deck they offer an alternative route but that aspect is somewhat accommodated by the reduction in height figure being conservative.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman/dude948)

Blah, Blah, Blah……


💩

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

Assuming the air is incompressible.

Non-Newtonian air molecules?

Wait 'til Thermopile hears of this.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Non-Newtonian
Speaking of which: video link

Could that mean piles driven into saturated silt and sand would be somewhat less supportive than expected? I wonder...



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17


Quote (Nukeman948)

Perhaps the pool chemicals evaporate slowly enough and are diluted enough by the fans airflow that they are not as hazardous as you seem to believe they are. We dilute these chemicals with dihydrogen monoxide to make them safe enough for our kids to swim in them and with air to expel their fumes to the atmosphere

I put salt in my food, swim in, and even drink chlorinated water at times, how harmful could they possibly be?

At this point I would like to bring back the entire post by Vance Wiley:

Vance Wiley (Structural)12 Jul 21 03:45

Quote (Vance Wiley)

I apologize for being off in the weeds a bit but this has haunted me for 35 years. I had nothing to do with this event but "Who Woulda Thought?"
The use of stainless steel to support a ceiling over an indoor pool sounds like a good idea, right? Not so much.
Corrosion-doctors.org - swimming pool collapse.

To bring this into focus with the present topic, it is common to spec stainless expansion bolts when exposed to weather. Is that a good idea in a seaside environment?

If this is too far astray just trash it. I will understand.
Thanks,
Vance

From the report:
The Federal Materials Testing Institute, based in Duebendorf, Switzerland, and the Federal Materials Research and Testing Institute of Berlin concluded that the collapse was the result of chloride-induced stress corrosion cracking. The steel rods had been pitted, causing the roof to cave in. The roof collapsed in a zipper-like fashion, starting with the corroded rods. The collapse continued as the remaining rods were unable to bear the increased load. Chloride is a major factor in corrosion of reinforced concrete, as in the case at Uster. The chloride was either already present in the concrete or came from the pool via water vapor. (figure courtesy)

Chloride can overcome the passivity of the natural oxide film on the surface of the steel. The steel, lacking its passive film, readily releases iron atoms into solution (in this case, moisture is present in the concrete due to the humid environment).

Although that report specifically mentions stainless steel the condition can also apply to carbon steels:
Stress corrosion cracking (SCC) in low and medium strength carbon steels

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

In San Francisco, they build on top of clay and use friction piles that don't go all the way down to the bedrock, too deep. So they rely on the friction to hold the piles in place, and thus create a stable building on top. As a matter of fact what I have found to my dismay too many times, the strongest friction force in the universe is the friction force that keeps two Lowe's 5 gallon buckets stuck together.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Jeff Ostroff (Electrical)11 Jun 22 23:55)

In San Francisco, they build on top of clay and use friction piles that don't go all the way down to the bedrock, too deep.

Quote (Grady Hillhouse and this is Practical Engineering)

The proposed fix to the Millenium Tower is to install piles along two sides of the building's perimeter. That may seem kind of simple, but there is a lot of clever engineering involved to make it work. Fifty-two piles will be drilled along the north and west sides of the tower all the way down to bedrock. Nov 16, 2021

What Really Happened at the Millennium Tower?

Original Cost to Build to Bedrock for Tower Like Millennium Put at Just $4 Million

(The SF does stand for San Francisco)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I worked on the demolition of an old retired steel structure that was sandwiched between more recent structures which remained in full use. It was a pulp mill which used chlorine and was generally a hot, humid and corrosive environment. It would not fall down, thus we had to dismantle it piece by piece without causing an unintentional collapse that would affect the attached adjacent structures. It was a bit of a nightmare scenario, but we prevailed with minimum collateral damage.

Take away --> it did not fall down on its own. Rust stains do not equal rebar vaporization. Chlorine on concrete does not equal dustation. For the common good of mankind, who are you people?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

I worked on the demolition of an old retired steel structure that was sandwiched between more recent structures which remained in full use. It was a pulp mill which used chlorine and was generally a hot, humid and corrosive environment.

And we all (should) know that chloride is commonly added to concrete mixes to allow the mixture to set more quickly and increases its initial strength. Without knowing how much chloride was present and the conditions in this building, both when it was built and through its lifetime, we are only muddying the waters. Some stainless steels react poorly to certain chemicals and conditions while other stainless steels have little to no reaction to the exact same conditions. And the same thing happens with different grades of mild steel. The phrase "correlation does not imply causation" comes to mind here.

Edit: Even the professionals use the wrong grade of steel sometimes. I made some good money from the wrong grade of baffle bolt steel.
https://www.nrc.gov/reactors/operating/ops-experie...



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym.P.le)

Using two NIST slide images, it's clear that the x11 stack drops with column lines K and L (I think L leads the way). The whole east wing of the building appears to twist grotesquely as the collapse is initiated.
That twist only amounts to every column in the east side buckling at once.

Also sorry if this has been mentioned, but the higher resolution image solves the disappearing penthouse mystery. The apartment with the light on (1110 I think) tore open and the apartment and roof above it didn't drop until a split second later.

Edit: Nevermind, I think that is a power flash in 1210. The X11 stack and the right half of the X10 stack dropped almost in unison. The roof above is from the back part of the building that fell just after
[

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Reverse_Bias (Electrical)12 Jun 22 02:05)

... twist only amounts to every column in the east side buckling at once.

A fair comment. The images took some work to scale seperately in the x and y axis. With possible lens distortion and/or reorientation, it's not the purest overlay, however the foreground and background are reasonably stable, so I'll just leave it for people to consider that the lagging structure was rocked when the collapse initiated. And we already know that it was not designed for this type of abuse. Imagine what a nominal earthquake could do.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Even the professionals use the wrong grade of steel sometimes
Thanks for sharing. Those documents raise some questions for me. Please direct me to an alternative thread if there is a more suitable one.

1) I'm surprised the designers couldn't reach a consensus on the grade of stainless steel "Type 347, Type 316, or Type 304".

2) Very surprising the construction is not fully welded internally.

3) "These lock tabs normally retain the bolt heads should they become detached".
Normally, but not always... I looked for a generous radius under the head but couldn't confirm it.

4) "A bolt head or bolt lock tab may detach if the degradation of the baffle-former bolt is significant". It is hard to imagine the forces necessary to cause the bolt lock tabs to become detached.

5) "The results also showed many bolts which the ultrasonic inspection identified as partially cracked retain a significant amount of strength". That is a very weak statement since it is known that the cracks progress to failure and the individual failures progress to clusters. Significant strength relative to what? What is the strength of the cracked bolts relative to the design strength and by how much does it reduce the factor of safety? or safety margin in normal operation and under failure scenarios?

6) Why is there a difference in the rate of degradation between up flow and down flow? Pressure fluctuations? Oscillation? Resonance?

7) "Degraded bolts plus additional non-degraded bolts have been replaced". Why were additional bolts replaced?

8) "Finding no damage to the replacement bolts and [BUT] 13 additional degraded original bolts". The wording could be taken to mean no damage to replacement bolts or original bolts, but I'm sure it means additional degraded bolts were discovered.

9) "The fact that a relatively small percentage of bolts broke during removal". How many broke during removal at other reactors and how was breakage remedied?

10) '“unzippering” as clusters grow'. It is concerning that the failures can progress.

11) "Shortest BFB bolt design [stiffness] with smallest head-to-shank transition radius [stress concentration]".

12) What is the recommended torque on the bolts when installed? What thread lubricant is used, if any? What surface treatment is used on the bolt threads? What is the pitch of the threads?

13) "Progression of random failures to clustering". Surely this means the baffles are deflecting.

14) "The WOG stated that because of the large number of baffle former bolts in the baffle assembly, the failure of a few bolts should not have a significant safety impact. Omitting to mention that as bolts fail additional stress is exerted on adjacent bolts causing a cascading failure into clusters".

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Sym P. le (Mechanical)9 Jun 22 23:02)

Using two NIST slide images, it's clear that the x11 stack drops with column lines K and L (I think L leads the way). The whole east wing of the building appears to twist grotesquely as the collapse is initiated.
First, I think you did a great job on this, the fact that NIST changed the aspect ratio to make their slide pretty didn't help.
I've been doing this powerPointy thing for thirty years now so I thought I'd give it a go:

I think I got it pretty close?

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

Rust stains do not equal rebar vaporization. Chlorine on concrete does not equal dustation

Thanks for sharing your experiences. The problem is that several unexpected conditions caused the partial collapse of CTS and we would like to understand what they were so that we can reduce the probability of similar events in the future. The example raised by Vance Wiley shows that there are conditions involving chlorine that can lead to premature failure of structural steel elements. So we need to explore those possibilities until we can prove or disprove them. For example, in the building you worked on was the steel treated to reduce corrosion and painted? How high were the stress levels on the structural elements? Were the elements designed to tolerate high levels of corrosion over their lifetime?

It certainly appears that the primary cause at CTS is the degradation of the structural steel-reinforced concrete, so we need to understand what was causing the accelerated degradation.

Is that reasonable?



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

high local humidity from vegetation and pool equipment room fan may have caused condensation to form on that column causing the dust to stick there more than the other ones.
I understand it had rained at CTS the evening before the collapse, it certainly did at Miami International airport. The humidity was high and the temperature was close to the dew point so any cool surfaces were likely to have condensation or be moist. The wind was blowing from the East as usual so humidity from the pool equipment room vent and plants was being blown to the West as usual. My feeling is that any difference between the surface moisture on those two columns was minimal. But the difference in the amount of dust is dramatic, so there has to be another explanation.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

> sorry if this has been mentioned, but the higher resolution image solves the disappearing penthouse mystery. The apartment with the light on (1110 I think) tore open and the apartment and roof above it didn't drop until a split second later

Yes. I was one of the people that was asking that question in earlier threads, based on the apparent lights on in X10 and the lack of a roofline gap. But the higher resolution seems to confirm that isn't the case, that the X11 and X10 stack dropped from the bottom (including the penthouse), and there's no roof gap because something else is obstructing the view of the sky above X10 (the roof level corridor as someone speculated back in an earlier thread maybe? indicating that the front of the building - column line 9.1 - dropped first?).

The other interesting thing from that image is that we can clearly see that the power got cut in the parts of the west wing, and apparently in 611 (that's where one of the survivors escaped from right? did she turn the light off?) but not 1110. Maybe some of you guys with the wiring diagrams can make something of what happened at the bottom of the structure from that.

Edit: The most interesting thing for me at this point is why, apparently, their investigation indicates that the issues were unique to CTS. Other 80s concrete multi level buildings, including CTN with a very similar design and presumably very similar construction materials, remain in normal use. And yet the likely failure scenarios we've been talking about in the last few threads on here - a punch through on the deck or detachment at the south wall - involve substandard initial materials, insufficient rebar, poor slab maintenance and corrosion, not just the thin column design of CTS.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red Corona)

that's where one of the survivors escaped from right?

Ileana Monteagudo (611) has always said she blew out her candle of the Blessed Virgin of Guadalupe as she grabbed her stuff and left. But she has not mentioned turning off the lights, as far as I know. Nor has she mentioned turning on the lights after she woke up. She consistently says she woke up and went to try to close her balcony door. So I suppose it is possible there could be a reflection on her window. But the enhanced image certainly looks like she turned the light on.

>>>>Edit: I just re-read some of the interviews with Ms. Monteagudo, and then ran into the GoFundMe her son has put up. This is secondhand, but the son says that when she got to the fourth floor in the staircase, all the lights went out. The fourth floor is also, of course, where she was when the building collapsed. I hadn’t previously seen this in the interviews with Ms. Monteagudo. So apparently, according to her son, she had light in the staircase until the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Red Corona (Computer)12 Jun 22 11:47)

Edit: The most interesting thing for me at this point is why, apparently, their investigation indicates that the issues were unique to CTS. Other 80s concrete multi level buildings, including CTN with a very similar design and presumably very similar construction materials, remain in normal use. And yet the likely failure scenarios we've been talking about in the last few threads on here - a punch through on the deck or detachment at the south wall - involve substandard initial materials, insufficient rebar, poor slab maintenance and corrosion, not just the thin column design of CTS.
Yes! I noticed that they said they were investigating damage from 87 Park etc., but most of the work displayed focused on the structure as built.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
My first Giphy, Suggestions encouraged.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

most of the work displayed focused on the structure as built.

Having sat through most of the NIST presentations, I agree that NIST has at this time a strong focus on defining CTS as-built. They talked several times about the difficulty of calculating dead load in such an old, poorly documented structure. This is why they are requesting the public to provide photos and videos taken over the years, even as they research historical real estate records and photos. They want to gain a better understanding of how unit owners added to the interior loads and when they did it.

Based on their analysis of the concrete, rebar, design, etc. that they hold in evidence, NIST also plans to reproduce and destroy key elements, such as column/deck connections, etc., in a condition as close to as-built as possible. I believe the intent of such studies is to get closer to identifying a trigger.

NIST’s purview is to make policy recommendations on how to prevent similar failures, so it seems reasonable to me that they would do this only after they know as much as possible not only about what fell down but also
 
why it fell down when it did. In contrast, KCE doesn’t have to meet the same objective. Their job is to figure out why CTS fell down; they don’t have to make recommendations that will keep similar buildings from falling down.

If you go through all the NIST presentations, you may notice (as I did) that their images seem to place a lot of focus on the K, L, M columns this group has focused on, rather than on the south perimeter wall connection or the gym that Prof. Lehman has focused on. At one point they even mentioned that they look at Internet content. Their database of evidence is going to be massive.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
Let me try again: (Any way to make it bigger? A better gif maker?)

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
One more time!



There we go!
edit (The "Before" (1st) frame is definitely before the first frame of the twitter iPhone video
edit 2 In the "early" (2nd) frame I'm reasonably sure that the Eastern most portion is not only twisting, but falling also
edit 3 increased brightness in before frame

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Cool_Controls (Electrical)24 Jun 21 15:51)

I noticed that there appear to be exhaust fans mounted at ground level along the western edge of the parcel are these for an underground parking?


Posted on Thread Number Uno!

Anybody see a CAP on top of that Exhaust Fan Assembly in those images? Don't see how the air exhausts immediately vertically without a hole in the top cap?

Perhaps Nuke can explain???

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

Thanks for sharing. Those documents raise some questions for me.


The answers to most of your questions would be proprietary information that Westinghouse is not going to release with all their competitors reading along.

Sorry, I don't have any Powerpointy training so this is the best I can do.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

SFCharlie - here is a corrected copy of the first NIST image of CTS. I cannot guarantee that the sizing is exactly the same as your original, but the levels are close to those of the 2nd image, to eliminate the glaring difference in levels between the two images on your GIF animation. Also it is a PNG not a GIF. If you need it to be a GIF, I can do that.

Edit - never mind, I see that you just did the same thing. :)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (sgw1009 (Computer)12 Jun 22 18:42)

SFCharlie - here is a corrected copy of the first NIST image of CTS.
Thanks!, Yes that's my point, this image is earlier than the first image in the twitter iPhone vid.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

"Anybody see a CAP on top of that Exhaust Fan Assembly in those images? Don't see how the air exhausts immediately vertically without a hole in the top cap?"

In designs like that that I've seen, that "top cap" is a cover for the motor, with the centrifugal fan mounted below. The venting is often downwards out the bottom of the larger diameter cylinder--closer to the ground.



spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

Anybody see a CAP on top of that Exhaust Fan Assembly in those images? Don't see how the air exhausts immediately vertically without a hole in the top cap?

Perhaps Nuke can explain???

Blah, blah, blah?

Begin here:
https://www.grainger.com/know-how/equipment-inform...

You see, this type of fan is commonly available in both downblast and upblast designs, therefore no separate rain cap is needed. In fact, if you take the time to look closer at all of those nice pictures you just posted, you can see that they are all of the upblast design.

Perhaps you could take the time to study this cutaway image. (since you seem to be too busy to do your own research)



Now, Morabito's drawings show a tube axial fan style for the replacement unit and that is what I thought I had seen in a fuzzy picture somewhere. If CTS still had the original fan installed, it was completely hidden in all that moist humid vegetation in that waterlogged planter. So the fan would be blowing all that moisture on the wall where it could condense unevenly and cause a dust cloud to stick to it.

Sorry, I don't have any Powerpointy training so this is the best I can do.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I am unaware of any images of what type of exhaust fan was in the blocked in area beside the parking deck planters. It could have been upblast or perhaps it was downblast like the image below. Where does the rainwater go that gets into upblast discharge area? Perhaps the fan is capable of expelling any moisture that gets into discharge area? Downblast would solve that problem either way, when upblast is not required.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

Well, the model numbers for the original fan schedule are obsolete but all the original upblast fans have a similar model number. Good evidence but not proof.
If you were an architect trying to hide an exhaust fan in a blocked in area and the price is the same for upblast and downblast, why would you even consider downblast, especially if you were exhausting pool equipment room fumes. You would want to blow that up and away from sensitive stuff like pool guests and plants and concrete, right? Restaurants always use upblast for kitchen service to keep the grease off the roof.
All upblast models have a drain for rain water that is usually easy to see: https://www.google.com/search?q=upblast+exhaust+fa...
Those that are intended to be used for restaurant service sometimes come equipped with a a grease trap on the drain. You can believe whatever you want.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

So even upblast exhaust fans drain condensed vapors and rain water at the base. If that drain port is not hooked up to say a drain line or that drain line has failed, then the condensate mix ends up on top of the parking garage ceiling, and able to soak into the concrete.

Either way, it appears pool chemicals would affect that area near and downwind of the exhaust fan significantly more. If it travels West to attach to say dew on plant leaves and run down into the soil in the planters to mix with the organic materials, salts, etc. then that mix is able to mix with water and soak down into concrete.

Further in Morabito's report there were ventilation fans that required new belts and bearings. So perhaps some of the ventilation fans were not operational? If that were the case, it also appears that the air intake for the pool room exhaust fan was thru louvered doors between the pool room and parking garage.

Thus auto exhaust would enter pool room where pool chemicals were stored, and mix vapors before exiting thru the pool exhaust fan. So another variable in the chemical stew.

Also how were the pool chemicals stored and did the garage flood waters ever mix with stored chemicals sitting on pool room floor, or at least mix with perhaps pool chemical spills on floor?

Edit: And of course during the hot muggy days in Surfside, the ventilation fans are bringing in an endless supply of CFM’s of hot humid, salty air, to condense on colder surfaces in the underground parking garage.

Edit2: I question how effective an exhaust fan is at dispersing chemical vapors when it is raining ☔️, and there is not a chimney stack at adequate height to prevent the chemical vapors from attaching to the rain water for example near point of exhaust, and ending up on on top of deck mixed with the rain water and surrounding materials.

Edit3: If I was the architect, I would also be concerned about noise levels associated with that up or own blast exhaust fan, due to people close by. Therefore limiting super high velocity fans?

Edit4: For that single person thinking the ‘Supervisory Event’ I was referring to concerning exhaust fans, U ASS_U_med wrong. I was referring to the ‘Supervisory Event’ called Deferred Maintenance that was clearly robustly exercised by the Condo Association In their ‘Supervisory Role’ as Property Mgr.

However, In the event of fire, ventilation systems should be controlled by modern Fire Alarm Systems or sensors and actuators on equipment, so they don’t feed the fire.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

MAn, I'm wasted!

I was up until 4 AM this morning uploading my video from the entire NIST presentation last week, and I found a 2-hour-long video online of live stream from the NIST zoom call, not just the 30-minute video we had seen until now.

I had to condense 10 presentations of slides from 6 hours of dissemination on Thursday into one video and get it under an hour. That was an engineering challenge on its own!

I spent 2 1/2 days working on this, and started the minute they uploaded the slides to the NIST site Wednesday.

I am still wondering if NIST has CTS security camera videos because their slide says they have "videos" plural high def. Would love to get my hands on them. I gotta have faith that there were videos and someone has them, unless the server was stores in the garage beneath the "11 Stack"

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
There are some details of the collapse that puzzle me deeply:
I can understand that after the first column punched through, that the pool deck fell, impinging on adjacent columns. The weight would not have been transferred immediately as parts of the deck were in free fall. Maybe the deck nearest the first column hit the floor and the remainder snapped itself down on an adjacent column like a bull whip?
What amazes and confounds me is what was going on during the next three minutes. Was some crack propagating through some structural member until gravity brought the rest down?
I don’t know.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

What amazes and confounds me is what was going on during the next three minutes.

From a witness statement perspective, the deck collapsed all at once at ~1:15 AM. Witnesses say the deck did not collapse in stages…it collapsed as a single event. As soon as the deck collapsed, witnesses say the building itself began shaking. This implies that when the deck collapsed, it buckled some columns so that the building immediately began redistributing its weight among the remaining columns.

As I understand it, based on what Mike Stratton claims his late wife Cassondra told him, the shaking is what woke her up. As Mike talked to his wife, he claims she said the building was shaking when it collapsed at 1:22 AM. Gabe Nir was in 111 after the deck collapsed at ~1:15 AM, and he says the building was shaking. Shamoka Furman was in the lobby from 1:15 to 1:22, and she called the shaking an earthquake.

I am not sure what you mean by mentioning three minutes. After the deck collapsed at ~1:15 AM, there was no separate event at 1:18 AM…although that happens to be the time that Adriana Sarmiento shot her garage video after the 1:15 AM deck collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Nir's hurricane shutters? Note the shutters are framed and sit on the deck.








RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

When I zoomed into your photo up above that does not look like the shutters to me as they would not be in one long piece like that remember they would be open like an accordion and probably in a 2 foot wide chunk. What that looks to me like is part of the pool deck in the black that you see on the top of it is the waterproofing membrane. That is where my money is bet

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA (Mechanical) 11 Jun 22 17:07)


I now see what you are pointing to and it is an interesting detail to be sure. It appears (ABC video) that the single buttress is uniquely dusted. It also appears to be in line with the direction of collapse of the east portion of the tower and a denser path/layer of dust.

I don't believe that it can add much to our understanding of the collapse initiation.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I find it interesting that powder blast at column is Due South of where the slab dropped at the planter over K line, and we know that area dust exit is bound by slab drop to North, Pool/Hot Tub to East, and parking deck hinge to the West.

Perfect storm to force powdered concrete exhaust towards South Wall. Deferred maintenance could mean duct from pool room was rusted thru, or gone?

Edit: Perhaps pool exhaust fan duct work is damaged or drops at opening in slab,and exhaust fan rolls and leaves 19”x19” opening to parking deck below. Or tree roots pushed fan off base? 🥴

Aren’t we seeing hinge effect in middle section of building dropping 1-1-1/2 floors instantly at K/L 9.1 etc. All floor slabs swing down making it appear building is falling down and back (North) at same time?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)13 Jun 22 05:08)

Thank you Maud. So the building was shaking from the deck drop at about 1:15 till the collapse at 1:22, or about 7 minutes.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff (Electrical))

What that looks to me like is part of the pool deck in the black that you see on the top of it is the waterproofing membrane. That is where my money is bet

I don't recall much long past discussion about what that dark area is (as a singular item). I think maybe it was conjectured that the dark coloration was due to shadow as it it might be the edge of a slab. Now that you mention the membrane it makes a little more sense. But the thing that nags me is that it looks to have certain geometric features that are not consistent with slab or shutters and it is dark colored from all angles of illumination could be truly black on one side and in shadow on others. I could name some things that it sort of looks like but that would be pointless and nothing that I image should actually be there.

To add: the membrane being overlaying randomly configured rubble could give the false impression if a contiguous 3 dimensional multifaceted object that could be imaged to be just about anything.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

So the building was shaking from the deck drop at about 1:15 till the collapse at 1:22, or about 7 minutes.

That’s more or less what the surviving witnesses have said. In the early interviews, they didn’t mention the shaking as often as they started doing in the later interviews. Plus all of the survivors were on the move or otherwise occupied during those seven minutes. So they would have been less likely to be noticing whether the shaking/rumbling/earthquake was continuous if they were running to escape or making calls to 911.

None of the witnesses explicitly said the shaking was continuous. I suspect the shaking was not continuous, based on an interview with Mike Stratton (410.)

Bear in mind that Mike Stratton has reported secondhand information and has also “refined” his version of what his late wife told him just about every time he has been interviewed. However, in one of his more recent interviews, he did say that it was shaking (not the deck collapse) that woke up his late wife Cassie, and that right before she screamed and the line went dead, she said the building was shaking again. He did not state explicitly that the building shook, stopped shaking, and then started shaking again, but there is that implication in the word again. If there was indeed a pause in the shaking, it would imply that the building lost its balance when the deck collapsed, then briefly caught it, and finally couldn’t maintain it.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)13 Jun 22 18:05)

Thanks again.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

Does anyone have a good photo of the pool equipment area, after the debris was removed?

I am not sure whether you were talking about the deck/hot tub area Jeff furnsished or the actually pool equipment room. Here is a better photo of equipment room area behind louvered doors, if that is what you were asking?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The "shaking again" comment might match up with the jolt that woke the 711 ring cam. Mike Stratton didn't say when in the call she said it though so you can't really tell.
Gabe Nir mentioned the building started shaking violently in the few seconds between the time they exited and the collapse started. That does imply the shaking accelerated just before the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Reverse_Bias)

The "shaking again" comment might match up with the jolt that woke the 711 ring cam.

Per the Miami Herald, Mike Stratton claims his late wife said “the building is shaking again” right before she screamed and it collapsed at 1:22. I agree that the shaking at that time may be the same shaking that woke up the Ring camera in 711.

In contrast, the Nirs were long gone by that time, having crossed Collins Ave and run up the street.

Also per the Miami Herald, Gabe Nir (111) has stated that he felt the building rumble and shake after the deck collapsed at about 1:15. Gabe and Chani ran to the door of the apartment, and their mom came back from the lobby to roust them. They ran to the lobby at about 1:16, and you can hear their voices in the background of the first three 911 calls that Shamoka Furman placed from the lobby. So they were in the lobby from about 1:16 to about 1:18. By 1:19 they were out on the street, and Gabe was calling 911.

My point with all that is that Gabe Nir wasn’t in the building in the seconds before the collapse at 1:22. The Nirs had left CTS between three and four minutes earlier.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

It also appears to be in line with the direction of collapse of the east portion of the tower and a denser path/layer of dust.
Thank you very much for taking the time to study the photos and search for alternatives. Please can you take a look at the image below and let me know why you think the dust did not stick to the East face of that column as shown below:


Edit: I found an earlier image that does appear to show some dust on the East side of that column but it looks as though the lighter dusting on the East was reduced after it rained. Judging by the cars and other objects.



Quote (Nukeman948)

Just speculating but high local humidity from vegetation and pool equipment room fan may have caused condensation to form on that column causing the dust to stick there more than the other ones.

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:


The dust on the North face of the column appears to be quite consistent in its coverage.




RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

A refinement to my trapezoidal failure theory earlier in this thread (26 May 22 07:20):

The concrete block infill along the building perimeter will not allow the slab to slope in that region, thus, at the perimeter, the slab can only slope beneath the less rigid glazed sections. The effect on the view from the Ring cam is that the credenza will sit level while the farther regions are free to slope, which could explain why the cam is not in plane with the kitchen counter top, even in the first frame.

A further implication is evident in the collapse sequence from the Park tower. At Column line M the failure is distinctly different on either side of the column with the west side dropping precipitously while the east side merely droops, at least initially. If the slab steps (from the pool deck to the interior slab) are considered as lintel beams, there is minor additional support from line K-L and L-M, a 7" step, while on either side of these, the step is 1'-6" offering much greater support.

If Column L buckles first and M is still stable, the thin lintel and block infill could create a condition where the slab suddenly shears off the west side of Column M leaving the column to continue supporting the structure to the east, if not only for a few moments. In the collapse video, it appears that Column K fails in near tandem with column L but Column M is delayed.


Profile showing column locations and CMU infill (darker) and perimeter step/lintel support (red/orange)


CMU infill causes perimeter slope to be stepped in the event of column failure (red line example)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA (Mechanical) 14 Jun 22 04:37)


It seems you've answered your own question. My own opinion is that between the momentum of the collapse and prevailing atmospheric conditions, a dense cloud of dust was pushed around that corner of the building. In the photo I posted earlier, it appears that there is a thick coating of dust on everything adjacent to and south of the corner but quickly thins out towards the pool. Just one of those things that has no other explanation.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:

As any chef could tell you, breading will not stick to dry chicken. You must first wet the chicken, preferably with an egg wash and provide proper seasoning.

Concrete dust will not stick to a vertical surface unless it is wet or sticky. The railings on the balconies are covered with dust in the same way too and yet there isn't all that much dust on the cars.
When dew begins to form it does not form everywhere all at once. It starts to form on cooler surfaces first. If the previous day was mostly cloudy but the sun came out after the building shadow covered that part of the wall it may be one possible explanation. It is also possible that someone had been watering the plants or kids had a water balloon fight there. I really don't know and I really don't care. But it seems obvious that that column was wet as were the railings.
Edit: I believe there was a drinking fountain in that corner too and if the water line that fed it, or any other water line in the area, was run along the wall it may have survived the initial collapse long enough to spritz that area.

Perhaps you could give us your explanation of why the dust stuck to that column and why you seem to think the explanation for it is so important.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

If the humidity on the column is coming from the vent and vegetation would it be consistent up the entire height of the column even if the bottom of the column were masked from that humidity by the adjacent wall as shown below:

IanCA, Thank you for posting pictures I have not seen, which appear to be from NY Times. I read the NY Post, not a NY Times reader, so I had not seen these images.

Ok, I will take the bait, in hopes of getting confirmation of what you are leading too. Structural Slab with the chemically changed concrete that is now a gypsum powder form, most likely had water trapped between structural slab and finished tile floor, thus the powder picked up moisture as the structural slab failed just below that area of the column or any number of reasons.

Either way, it appears the first concrete failure, and the noise heard by witness of small collapse before deck failed, could have been that small portion of the slab that fell on the EAST side of the block wall around the pool exhaust fan.

If that small section fell first, then that could be the 'specific' opening that serves as the Southern Focused initial VENT of powdered concrete, thus explaining the heavy concentration of Powder mostly on North FACE of Block privacy wall column and evenly coated from bottom of block pilaster to top of pilaster......

Edit: Of course a slab drop South of K11.1 ( Column under Planters) where deck sagged 2 weeks before collapse), could be a direct result of the slab detaching from South Wall and retracting just a bit, in area of "Focused' Dust Blast at South wall pilaster, but not falling 2 weeks earlier. So once Parking Deck/Patio Deck Collapsed, there was already a specific opening to vent the powdered mix at that pilaster. Slab drop does line up N to S with this area of South Wall.

IanCA, Feed Back Requested Please!

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le (Mechanical)14 Jun 22 05:01)

A refinement to my trapezoidal failure theory earlier in this thread (26 May 22 07:20):

Sym P. le what I notice in your GIF when holding my mouse on lower floors vs upper floors is that the top 2 to 3 floors drop a greater distance in same period of time as the lower say 10-11 floors do.

Clearly if you adding some floor lines to your GIF, I believe it would show this accelerated rate of drop on upper 2 or so floors vs rest of floors below.

I think I see the slight lag of M column line as it tears away from Easter portion of building.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Perhaps because the drop between the two frames is one and a half floors it gets confusing as to what is being seen. I think I see what you're looking at but when I look closer it just seems illusory.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. Le)

Perhaps because the drop between the two frames is one and a half floors it gets confusing as to what is being seen. I think I see what you're looking at but when I look closer it just seems illusory.

Illusory or Science? From my memory the 13th Floor Penthouse was very open floor plan with long slab spans, and I believe the 12th floor Penthouse was similar as compared to the 11 floors below. So less Block In-Fill Walls, and longer spans between columns.

Thus, are we seeing the top too slabs hinge back (North) a greater distance, in same time period, due to Trigonometry of the longer un-supported slab spans from outer column line to the next column line North?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Sym P. le (Mechanical)14 Jun 22 05:01)

Great work!
I had to add the basement and pool to help me make sense of it all...

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (thermobaric (Military)14 Jun 22 13:53)

what I notice in your GIF when holding my mouse on lower floors vs upper floors is that the top 2 to 3 floors drop a greater distance in same period of time as the lower say 10-11 floors do.
Please don't get ahead of the video, so many frames passed in between the two hi-res frames we have!
(I have removed the repeated frames of the twitter i{hone vid.)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I can see the parapet wall at the 12th story roof line, appears to roll backwards (North) a lot more than the 13th floor roof parapet, along KLM stack, while the Column line between K and L for the 12th and 13th floor, buckles outward at the 12th floor roof line

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

We're in the wrong business...

https://www.sun-sentinel.com/local/miami-dade/fl-n...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Do you feel any better?

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I found the floating house video at Yellowstone on the Sun-Sentinel link, very interesting.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I just uploaded my video tonight analyzing the $100 million lawyers fees filing, it was 400 pages. But in reading through it for the video, I found this interesting tidbit about one of the plaintiff lawyers:

SMB Took the Lead Questioning Role at Depositions to Secure the Devastating Admissions Which Compelled Settlement
28. Construction cases are often won and lost in depositions. Depositions were taken of seven individuals associated with the design and construction of 87 Park. Mr. Goodman was the lead questioner on five of these depositions and assisted Ms. Bucciero in preparing for the other two depositions, which she took. The depositions taken by the team of Mr. Goodman and Ms. Bucciero, with tremendous assistance in preparation from Mr. Dordick were essential to this resolution.

29. Hundreds of hours were dedicated to preparing for and taking these depositions, and it proved to be of tremendous worth to this case.

Mr. Goodman's effective questioning elicited admissions that were utterly devastating to the 87 Park defendants. This included
(1) the deposition of Garfield Wrey, the lead geotechnical engineer on the project whose testimony buried the other 87 Park defendants for not following his warnings;
(2) the deposition of NV5 senior executive Eric Stern who utterly broke down at his deposition and admitted fault on behalf of NV5; and
(3) the deposition of Kerry Lopez, the author of the "F**k That Wall" daily report whose testimony all but guaranteed punitive damage finding against the general contractor, John Moriarty & Associates of Florida, Inc.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I would love to read those depositions.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Lead geotechnical engineer ignored. How many other engineers were ignored in the construction of Park?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (thermobaric)

Structural Slab with the chemically changed concrete that is now a gypsum powder form
I certainly think the structural concrete of the parking deck adjacent to the southern property line wall had experienced the most degradation and when it collapsed it also created far more dust than concrete it good condition would.

Quote (thermobaric)

most likely had water trapped between the structural slab and finished tile floor, thus the powder picked up moisture as the structural slab failed
I think it is highly likely that the concrete in that area was more porous as a result of the degradation and retained moisture more than usual, but that it cycled with the weather and irrigation runoff. I also think the dust was dry enough at the time of collapse to be freely released into the air.

Quote (Nukeman948)

Perhaps you could give us your explanation of why the dust stuck to that column and why you seem to think the explanation for it is so important.
I appreciate you asking.
I agree that the columns were all relatively damp but I believe that the difference in dust level was due to the difference in proximity to the source of the dust rather than any significant difference between moisture levels. This is important because I believe it indicates the extent of the concrete degradation at the southern property line wall and is a further illustration of the sequence of the collapse of the deck. If the parking deck collapses first at the southern property line wall creating a large volume of dust and the remainder of the deck then collapses, the initial dust would be rapidly forced up through the gap below that column, making it very likely the column would receive a thick and even coating of dust. If the deck collapses first at column K13.1 (74) then the dust will be forced more equally north and south within the garage and should be visible in the video by Adriana Casillero.

Quote (thermobaric)

If that small section fell first, then that could be the 'specific' opening that serves as the Southern Focused initial VENT of powdered concrete, thus explaining the heavy concentration of Powder mostly on North FACE of Block privacy wall column and evenly coated from bottom of block pilaster to top of pilaster......
Essentially yes, but I believe it was the section of deck to the west of the column that failed first.

EDIT:

Quote (Sym P. le)

Just one of those things that has no other explanation.
Please consider the explanation above.

Thanks for your work on the drawings.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

I agree that the columns were all relatively damp...

No. You know that is the complete opposite of what I've been saying.
The reason the dust stuck to only one column is because only one column was wet. After the dust hit that column, all the dust that didn't stick to that column would be dispersed in a dust cloud all around the area. If all the columns were wet we would see a gradient of dust quantities on the columns leading us back to the source of the dust. I also believe that dew is the reason dust stuck to the vertical parts of the balcony railings (something you are avoiding talking about) and very little on the cars that were right next to the wet dusty column.
But none of the dust patterns I see indicate a larger quantity of dust coming from that one location.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

No. You know that is the complete opposite of what I've been saying.
Sorry, I didn't intend to misrepresent your position.

Quote (Nukeman948)

If all the columns were wet we would see a gradient of dust quantities on the columns leading us back to the source of the dust.
I agree, and I do see a gradient of dust on the wall. Do you see that? I should have credited Joe Raedle. The original image is here: link.

Quote (Nukeman948)

dust stuck to the vertical parts of the balcony railings (something you are avoiding talking about) and very little on the cars that were right next to the wet dusty column.
I didn't address the railings because I hadn't studied the railings and I wasn't sure if you had a particular image in mind. I think your observations agree with the point I'm trying to make. I am asserting that the dust was blown upwards and the balconies are above the deck, only heavier particles would fall back onto the cars.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I hope the latest gif will shed some light on the timing of the huge spurt of dust sent into the air at the southwest corner of the pool deck.
By this time, I suspect that a lot of debris from the collapse had accumulated in the basement and that the collapsing tower blew this dry dust out forcefully?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)


In SFCharlie’s GIF, I see the cloud of dust from building collapse originating closer to column I9.1 and moving East as it vents. It appears to me, the well coated pilaster at South wall was an earlier dust blast, when the parking garage/pool deck collapsed along on near K line.

EDIT: In photos there was a white PVC line attached to east side of planter wall near pool room exhaust fan location. I also saw what appeared to be irrigation lines inside the planters. Would it not be logical that the plant irrigation system kept the south wall K line pilaster wet, thus the pilasters to the east were not as damp due to no irrigation system near them. Here is image IanCA posted above showing what appears to be white PVC irrigation line.

Look closely at image below. Looks like rebar between south wall and slab is still there, but missing concrete where PVC pipe turns down to garage and Exhaust Fan Can laying to the west. Looks like at that hole everything on one side fell West and on other side it fell East. Also note it appears the structural slab and topping slab that was previously attached to exposed rebar, did a Back Flip to the East.

Like SFCharlie’s Bullwhip analogy

Very interesting!


:





RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

I think your observations agree with the point I'm trying to make.
Wrong. I'm repeating myself but, none of the dust patterns I see indicate a larger quantity of dust coming from that one location.

What I am seeing is indicative of a gradient in the moisture on the wall and its ability to retain dust. Any dust that was expelled with enough force to reach the balconies 40' up or more will be distributed over a much larger area, that gradient will be observed over a much larger area, and will not cling to dry vertical surfaces.

Now, if we can agree that this dusting event was the first one, caused by the pool deck collapse, that would imply that there was a much larger air and dust blast as the entire building fell. This second blast would have blown all of the dust off the walls and cars from the first dusting except for where it was stuck to the wet surfaces. I'm repeating myself but, none of the dust patterns I see indicate a larger quantity of dust coming from that one location.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

They showed some cool comp[uter imaging and modeling on his insider video on that June 15 update

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
Just when you thought it was safe to go back in the water...
Link

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

I hope the latest gif will shed some light on the timing of the huge spurt of dust sent into the air at the southwest corner of the pool deck.

@SFCharlie, thank you very much.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

Sym P. le (Mechanical)15 Jun 22 18:02
Thank you very much for that image. The changes in brightness/ contrast/ saturation/ color balance? really help to make the thickness of the dust on the wall and column stand out.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff (Electrical) 15 Jun 22 23:58)

... some cool comp[uter imaging and modeling

Interesting also that he has the K column highlighted (direct video link)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

What I am seeing is indicative of a gradient in the moisture on the wall and its ability to retain dust.
Thank you for taking the time to help me understand your thoughts on this topic.
Can you help me understand why:
1) Why the dusty column appears to be so much more dusty than the adjacent column to the East when the prevailing wind was mostly from the East that evening. Meaning that the pool equipment room exhaust and plant moisture was being blown away from the dusty column. Was it not?
2) Why the dusty column appears to be quite evenly coated with dust from top to bottom when the bottom half is protected from the free flow of the wind by the adjacent wall (with the water cooler) and the top half is relatively exposed to the flow of the prevailing wind?

Here is an earlier image with annotation added for clarity:


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I would like to ask if the dust is due to the huge quantity of the blast just as the east portion to the tower starts to collapse?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Am I the only one who finds the apparent lack of dust on the plants to be odd? They're near the dusty column, and if there was any dew, it seems the leaves would have been wet?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Is it possible that the darker pilaster was at some point restuccoed so it is simply a different color from the other pilasters? I have seen irrigation systems damage nearby structures, causing them to need repairs. The property manager would be able to tell us…

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)16 Jun 22 16:30)

Is it possible that the darker pilaster was at some point restuccoed so it is simply a different color from the other pilasters?
Since the sides of the column are still dark brown and the walls just to each side of the column appear grey in that area, I suspect dust.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

One more thing I noticed from the high res gif. There appears to a bend pretty close to the shear wall in the central floors of the X10 stack.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

Is it possible that the darker pilaster was at some point restuccoed so it is simply a different color from the other pilasters? I have seen irrigation systems damage nearby structures, causing them to need repairs. The property manager would be able to tell us…

I thought the same thing when I first noticed it but we can rule that out MaudSTL, because the wall and column were back to looking clean and consistent after a couple of rain showers and before July 4th. Please see below.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Debirlfan)

Am I the only one who finds the apparent lack of dust on the plants to be odd? They're near the dusty column, and if there was any dew, it seems the leaves would have been wet?

I think that is a good observation. I think one possible explanation is that the plants have tilted to the north away from the wall. If dust was primarily forced directly upwards from the debris (from the deck) immediately adjacent to the wall the plants would be far enough out of the way to avoid being directly coated.

Looking at the image posted by zebraso on 13 Feb 22 03:41 we can see there was dust on the plants but apparently not as think as it is on the column we are discussing. It also shows how far the plants had tilted to the north.



This drone view from overhead, taken later after the rain, shows the size of the gap between the plants and the wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

It looks like the planter soil did not stick to the pitch inside the privacy wall, but the dust did. Electrostatic charges?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

If the plants were sufficiently root-bound, they probably 'contained' the dirt, especially if the soil was damp.

Also consider - if they were root-bound, that would contribute to adding some pressure on their container. One more stressor adding to the problems with the deck?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

There seems to be a high probability all those plants were root-bound. Never the less I was thinking that the mechanical force involved in pulverizing concrete might impart a static charge on the dust particles assuming the concrete was dry - not *all* of the concrete was damp. It's less likely in high humidity, so I am not really sure about it. The concrete would not be carrying a charge before the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

If the irrigation line was pressurized at the time of the collapse, is it possible that it sprayed the pilaster during the collapse so that it became a dust magnet?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I'm sure that there are many contributing factors. I feel that the twitter iPhone video suggests that one of them was the blast of dust at the southwest corner of the pool deck (plaza) as the east tower began to collapse.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The dust on the pilaster seems extraordinarily well targeted…very accurate. I’m trying to understand how that targeting could have occurred.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)17 Jun 22 23:26)

The dust on the pilaster seems extraordinarily well targeted…very accurate. I’m trying to understand how that targeting could have occurred.
Thanks, that make your question clear.
Just below where the dust appears on the wall, there is a section of pool deck at the southwest corner, that is turned over, leaving a void. It makes sense to me that the blast that turned this corner over, blew a concentrated stream of dust up onto the wall.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (

Quote (SFCharlie)

SFCharlie
)

Just below where the dust appears on the wall, there is a section of pool deck at the southwest corner, that is turned over, leaving a void.

MaudSTL and SFCharlie, thanks for clarifying. I agree.

Quote (SFCharlie)

It makes sense to me that the blast that turned this corner over, blew a concentrated stream of dust up onto the wall.

I suspect the void in that corner was created when the Southern edge of the parking deck disintegrated. And the concentrated stream of dust was blown up the wall and column when the remainder of the pool deck and parking deck collapsed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Here is an image that combines a few different ideas:

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (IanCA (Mechanical)18 Jun 22 05:13)

I suspect the void in that corner was created when the Southern edge of the parking deck disintegrated. And the concentrated stream of dust was blown up the wall and column when the remainder of the pool deck and parking deck collapsed.
Yes, a reasonable suggestion. I realize that I don't know the sequence of events. I just see this huge geyser of dust going straight up later in the sequence, but don't see dust hanging in the air earlier?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (IanCA (Mechanical)18 Jun 22 05:15)

Here is an image that combines a few different ideas:
Wow! I love it!

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

Wow! I love it!
SFCharlie, thank you, I'm very pleased to hear that. Please let me know if you see anywhere I need to make any adjustments or improvements. Would a new sectional view through the garage at the parking deck with more detail be helpful, do you think?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (IanCA (Mechanical)18 Jun 22 18:3)

I think it is just fine. Simple is best. If you find more info, I would suggest that the new info go into a new image?

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

Please let me know if you see anywhere I need to make any adjustments or improvements.

With IanCA's latest Visualization tool, I am trying to understand the possible implied sequence of events. I have added numbers at end of his arrows trying to understand perhaps an implied sequence of events.

It appears that perhaps step one is the E-W cracking of slab under parking deck planter North side wall, causing planters to roll North, and at some point break the water cooler line and sprinkler lines.

Which then causes deck to retract at 2a and causes tension break in the top of the slab at 2b at same time.

It would appear initially, the E-W rebar just north of the 2b break is temporarily restraining the E-W and the N-S rebar load, and transferring the load.

The loss of N-S tie to wall plus shifted loads causes the complete failure at 3.

Since their is a relatively small liner rectangle of parking deck slab retracted from the South wall, and the area under planters is where concrete and rebar disintegration are worst, there is more powdered concrete in the air at south wall break, when rest of parking deck collapses and creates a high pressure blast of air to blow the heavy dust concentration out and onto the exposed South Wall of broken parking deck Planter, and Pool Deck Pilaster.

Parking deck drops to the West at Same time as to the North, and breaks around pilaster, thus forcing dust cloud out in only one direction, which is towards south wall break at wall?

IanCA, obviously you have deeper thoughts and perhaps you can fine tune this attempt at understanding your Imagine Tool Provided.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I have a longer timeline:
Sometime before 87 Park construction was initiated, the pool deck slumped (due to design and construction errors (to achieve goals of cheap and time to market)) and water puddled near the focus area of IanCA's image.
When 87 Park was built, the pavement was removed to the south of the parameter wall, exposing rebar and creating a void that gravel and water could pour into.
Two months before the collapse: the tension in the pool deck and the South wall of the North part of the tower being cantilevered off the stepdown beam, twisted the stepdown beam enough to cause the sliding doors above it to become very difficult to operate.
Two or so weeks before the collapse, the slab under the planters north of the access between the valet parking and the pool deck started to give way, puncturing itself on the column under it.
This increased the tension in the deck catenary. The increased tension and the damage at the south wall/deck joint allowed the west half of the deck to slump, punching through at many columns.

This increased the twist in the stepdown beam to the breaking point near its west end near the gym.
Bang: queue the twitter iPhone video.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Thermobaric Thanks very much for analyzing the information and contributing to our understanding.

Quote (thermobaric)

I have added numbers at end of his arrows trying to understand perhaps an implied sequence of events.
If you would be willing to upload a version with numbers we can be sure to use the same reference.

Quote (thermobaric)

It appears that perhaps step one is the E-W cracking of slab under parking deck planter North side wall, causing planters to roll North,
Yes, I think so, although I am not yet 100% sure which way that crack propagated. Although I think it more likely propagated from the West to the East because in that way the crack is moving further away from the Southern wall and increasing the volume of less well-supported concrete. In that case, the crack is diverging from the wall. I think it is less likely the crack converges with the joint at the wall. Also I see the corner of the pool deck collapse that is bounded by a curved fracture centered near the column as the termination of that phase of the collapse. Please see below:


Quote (thermobaric)

at some point break the water cooler line and sprinkler lines.
I see what appears to be two PVC pipes (supply and drain?) along the pool deck side of the wall between the pool deck and parking deck leading to the water cooler and it appears the water cooler was included in the area associated with the early part of the collapse. The supply line could have been broken at that stage. As the pipe was breaking there probably was some water jetting out, but I expect that soon developed to an open pipe with a fairly well-organized flow, such as from a hose. So I think the chances that water would be entirely responsible for the dust sticking to the column as suggested by Nukeman948 is relatively low.

Quote (thermobaric)

Which then causes deck to retract at 2a and causes tension break in the top of the slab at 2b at same time.
Yes, agreed.

Quote (thermobaric)

Since their is a relatively small liner rectangle of parking deck slab retracted from the South wall, and the area under planters is where concrete and rebar disintegration are worst, there is more powdered concrete in the air at south wall break, when rest of parking deck collapses and creates a high pressure blast of air to blow the heavy dust concentration out and onto the exposed South Wall of broken parking deck Planter, and Pool Deck Pilaster.

That is a good summary, thank you.
"relatively small liner rectangle of parking deck slab", I estimate the size of the area of slab that detached from the wall is about 30 feet East-West by 10-15 feet North-South. My original estimates for the weight of that volume of concrete (structural and stampcrete) were above 40 thousand pounds. Is that a reasonable estimate, I wonder?

"there is more powdered concrete in the air at south wall break". Not only in the air but I suspect there was a large ammount of dust in the debris on the garage floor.

"onto the exposed South Wall of broken parking deck Planter, and Pool Deck Pilaster". Exactly.




RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

When 87 Park was built, the pavement was removed to the south of the parameter wall,

Here is an image I found that gives some idea of the work that went on adjacent to the CTS Southern property line wall.


Quote (SFCharlie)

Two or so weeks before the collapse, the slab under the planters north of the access between the valet parking and the pool deck started to give way, puncturing itself on the column under it.
I think it is possible that partial ductile failure at column K13.1 was sufficient to transfer enough load to the weak concrete at the Southern property line wall/parking deck to cause a rapidly increasing failure (over a few hours) in that area. But I think there has to be sufficient dust and debris at the bottom of the wall before the main area of the deck collapses to get the dust on the column in the way we see.

EDIT: It's ironic there should be a black vehicle like that in the foreground. EDIT: But I see now it is an F-150, so not ironic.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

Yes, I think so, although I am not yet 100% sure which way that crack propagated. Although I think it more likely propagated from the West to the East because in that way the crack is moving further away from the Southern wall and increasing the volume of less well-supported concrete. In that case, the crack is diverging from the wall. I think it is less likely the crack converges with the joint at the wall. Also I see the corner of the pool deck collapse that is bounded by a curved fracture centered near the column as the termination of that phase of the collapse.

IanCA, I follow your logic on the West to East diverging progression of the possible initial break under North Parking Deck Planter wall, and feel the tear at the East end that you illustrated in the pool deck, is consistent with that being a temporary stopping point of initial collapse propagation. And of course we have a HD Diesel Truck sitting near that possible initiation point, at the time of collapse (perhaps more than double the 'fly spat' car that landed against it?)

Edit: I added image I omitted to post, with the sequence numbers above annotated.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

As the (water cooler) pipe was breaking there probably was some water jetting out, but I expect that soon developed to an open pipe with a fairly well-organized flow, such as from a hose. So I think the chances that water would be entirely responsible for the dust sticking to the column as suggested by Nukeman948 is relatively low.

The water cooler would only need a 1/2" pipe to feed it with a reducer to 3/8" or even 1/4" at the connection. However it was not the only pipe that could have sprayed water on the wall. Irrigation pipes were mentioned as just one possible example.

Since someone already mentioned the fire sprinkler system was likely damaged at that location, I checked to see what was there. A 2" header pipe forms a loop system so it can be fed from both directions in case there is a break like this one and the 100 hp pump is more than capable of maintaining enough flow @ 130 PSI and 750 GPM to keep that wall doused in water for hours and the pump has the generator to keep it running even if the electric supply is cut off. Perhaps you could see this as increasing the chances of sufficient amounts of water getting on the wall.
Perhaps "a high pressure blast of air to blow the heavy dust concentration" would also blast water through the same opening as the dust was blown through.
Unless someone posts a better idea of what could cause dust to stick to that wall, I'm going to "stick" to the water theory.

Edit: I see the original fire pump was 750 GPM @ 95 PSI (130 psi was for the new pump) but my calculations show 70 PSI would be needed just to reach the 12th floor so 95 PSI would only give 25 PSI at the sprinkler heads and be insufficient to meet the needs at the penthouse level with the new fire code.
From NFPA 20: "A fire pump’s size is dictated by the most hydraulically demanding area of the fire protection system. In many high-rise buildings, this can be the automatic fire standpipe system demand which requires 500 gallons per minute at 100 pounds per square inch at the top of the most remote standpipe, plus 250 gpm for each additional standpipe, up to a maximum of 1,000 gpm for wet systems or 1,250 gpm for dry systems." Well that explains where the 750 gpm comes from. So if there is 100 psi at the top floor there would be 170 psi minimum standby pressure (if my math is right) in the fire sprinklers on the parking level.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (IanCA (Mechanical)18 Jun 22 21:08)

I think we are agreeing with each other. If you see a difference, I don't see it.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I thought that Maud had stated that the witnesses saw the whole deck collapse at one time? I could be confused.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

I think we are agreeing with each other. If you see a difference, I don't see it.

Yes, I believe we broadly are in agreement. I only rephrased it slightly to reduce the chances of misinterpretation by other readers in the future. Similar to the way in which things are often described twice in legal documents to clarify a point, using two slightly different perspectives. I suspect I am less certain about the extent of the failure at column K13.1. I studied the planter wall above that column in more detail and I feel more confident now that the wall was displaced inwards toward the plants. Meaning the vertical displacement would be less in reality than it appeared.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
I think that, since there was no sand nor pavers between the planter and the deck that any downward displacement of the planters required a failure of the deck, even if it hadn't fallen yet.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Since someone already mentioned the fire sprinkler system was likely damaged at that location, I checked to see what was there.

Thanks very much for taking the time to research that aspect and provide that perspective. I will give that some more thought. I'm interested to see which way the pipes ran and where they would likely have broken and at what time in the sequence and whether the deck shielded the wall.

Quote (Nukeman948)

I'm going to "stick" to the water theory.

Water off a duck's back?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

I thought that Maud had stated that the witnesses saw the whole deck collapse at one time? I could be confused.

No surviving witness actually saw the deck as it collapsed at about 1:15. But multiple survivors heard it collapse, and to all of them it sounded like a single loud event, whether they were in the lobby, the elevator, 111, or by the pool at the Blue Green Resort across the street.

The first survivor we know of who saw (after the fact) that the deck had collapsed was Sarah Nir, followed by Shamoka Furman, in the lobby. Since they were looking at the collapsed parking deck and the clouds of dust in the dark, I have always doubted that they could have seen beyond the collapsed parking deck to the collapsed pool deck. This theory is born out by the fact that all of the surviving witnesses who saw the collapsed deck from the lobby and/or porte-cochere described seeing (and hearing) the cars jutting out. None of them talked about seeing that the area beyond the parking deck had collapsed.

We know second-hand that the shaking building woke the late Cassie Stratton in 410. She did not see the deck as it collapsed…she saw it after it had collapsed, and then called her husband at 1:20.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

In seeing all these theories on how the pool deck separated from the south wall, 2 things still bother me.

1) I still don't see how that planter next to the wall could have caused the pool deck to break apart there and pull away from the wall, it is too close to the wall, and so any rotational or moment arm forces would not likely have enough strength to pull it from the wall. Tha area was never mentioned as a problem area prior to the collapse, unlike column 76, which had water leaking down from the pool deck.

2) IF the slab separated from the south wall with cars on it, why did they fall back into the V-shape at the center of the slab (driving lane of the covered parking deck), instead of cars falling forward toward the south wall since the slab separated from the wall?

This is why I think the punching shear initiated somewhere north of that first line of cars near the south wall, causing them to fall back into the V. This would then cause the slab to detach from the south wall. SO I am looking at that detachment of the pool deck slab from the south wall as a result of the pool deck punching elsewhere, instead of the south wall separation being the cause, it is the result.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

But multiple survivors heard it collapse, and to all of them it sounded like a single loud event
Understood, but there were loud structural events before that and I'm not sure we know what they are. Do we?

For example when I look at the Theory/Hypothesis spreadsheet here:

Cell F3 [Proven Evidence] identifies three collapses at 1:10 [preceding collapse], 1:15 [main deck collapse] and 1:22 [main building collapse].

And those collapse events were preceded by multiple knocks and multiple louder knocks. At least two waves of multiple structural events before the first [unidentified] collapses.

Is that correct?

EDIT: corrected name of spreadsheet.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff)

I still don't see how that planter next to the wall could have caused the pool deck to break apart there and pull away from the wall,
Jeff, Thanks for raising this concern. I will try to describe tomorrow in more detail how I think it could have happened.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@IanCA, no surviving witness saw evidence of a physical collapse at 1:10, when a loud crashing sound was heard in 111 and in the lobby.

Banging noises were heard in 111 from 11 PM until at least 1:10 AM, first by Chani Nir and then by Sarah Nir and Gabe Nir. They heard the loud crashing sound in 111, and Shamoka Furman heard it in the lobby.

There are no witness statements to support a visible collapse at 1:10 AM. The Vazquezes were in the garage after 1:10, when the loud crashing sound was heard, and before 1:15, when the deck collapsed as they rode the elevator to the lobby. They heard very loud cracking seconds before the deck collapsed. We do not know what parking space the Vazquezes used, so we do not know the path they took to walk to the elevator lobby. But they did not report seeing evidence of a collapse while they were walking from their car to the elevator lobby.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Not sure if this adds anything, but a new interview with the father of the boy that survived:

Link

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

no surviving witness saw evidence of a physical collapse at 1:10,
@MaudSTL thank you for responding. Can we agree that there was a collapse at 1:10 before the main deck collapsed?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

It's clear from the reports of noise that there was something structural at 01.10. It doesn't appear to have been a collapse visible in the garage though. So I would say it's more likely to be internal structural failure in the deck than an actual collapse. Perhaps the deck starting to punch at column 76 but still hanging on its rebar mat, or the south wall starting to let go, dropping the ceiling a few inches, but not actually falling yet.

We still don't know which parking space they used but we do know that (i) they must have driven down the ramp and (ii) they walked into the lift room, and any path between those two places gives a view of pretty much the whole garage. I find it hard to believe they wouldn't have noticed fallen ceiling slab, or even a lot of dust in the air, if anything had collapsed when they came home.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red Corona)

We still don't know which parking space they used but we do know that (i) they must have driven down the ramp and (ii) they walked into the lift room, and any path between those two places gives a view of pretty much the whole garage. I find it hard to believe they wouldn't have noticed fallen ceiling slab, or even a lot of dust in the air, if anything had collapsed when they came home.

However, if their parking spot was say in North East Corner near the East Stair Tower and I lived on first floor, I for one would take the stairs as the shortest direct path to my apartment/condo. Especially if justing getting back from a gym workout.

So it is possible they immediately turned left off entrance ramp? If 1st collapse was closer to elevator, perhaps they were not aware. I see in recent photos posted the deck delaminated at South Wall. Thus perhaps all that fell initially was the 3/4” concrete. cover below rebar grid?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

You will stretch your imagination to any length to make shit up.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (Sym P. le (Mechanical)19 Jun 22 20:25)

AND, I feel any dive into the minutia of which crack broke first after the K14.1 punch through 2 weeks or so before the collapse isn't very interesting UNLESS it relates to transmitting the collapse to the tower.

SF Charlie
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)
The problem in my mind is, how was the energy of the collapse "stored" during the seven minutes between the deck and tower collapses?
Was the North tower swaying north and south while the West (Collins side) tower was swaying east west? Were they transferring the energy back a forth between the two? If so, the (stress, strain, distress) between the two must have been horrendous. ( I can't image what it would have been like for the West tower to sway east slamming into the north tower.)
What was going on during those seven minutes?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

Can we agree that there was a collapse at 1:10 before the main deck collapsed?

No. We can agree that surviving witnesses heard a loud crash that some of them assumed was a collapse. Since no survivor saw a collapse, we cannot know if something actually fell.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff)

1) I still don't see how that planter next to the wall could have caused the pool deck to break apart there and pull away from the wall,

1) The area of the parking deck that collapsed is essentially bounded by column line G.1 to the West and by column line K to the East. We know that the area of the parking deck West of column line G.1 did not collapse and most of the area of the parking deck East of column line G.1 did collapse, so there was a weakness or discontinuity north-south along column line G.1. We can see that the pool deck East of column line K has collapsed against the southern wall leaving the top surface of the deck concave, but the top surface of the parking deck West of column line K is convex, so there is also a discontinuity or weakness running north-south along column line K that extends from the southern property line wall north to somewhere between column lines 14 and 15.

We can observe cracks in the parking deck area between column lines G.1 and K that run generally east-west that are open at the top. So I think it is reasonable to conclude that the top surface of the deck failed in tension. The areas of deck to the north and south of the crack are lower than the crack. The question then becomes which area failed first, the area to the south of the crack or the area to the north? To understand the answer to that question we can consider the two scenarios in detail before the crack is formed and decide whether they are viable.

Scenario 1) the area of deck south of the crack first becomes unsupported. The collapse is progressing from the south to the north. In this case the area bounded by column line G.1, K and the southern wall is now supported by six columns, three along column line 14.1 and three columns along column line 14 / 13.1. The area of the deck south of column line 14.1 is supported in cantilever and the top surface is in tension. Some combination of loads and concrete strength in that area can allow the concrete to crack in the way we see. The area of deck north of the crack and north of column line 14 is sufficiently constrained by the three columns 23 feet to the north along column line 14 / 13.1 to resist rotation of the deck surface upwards. Scenario 1 is a viable condition to produce the top surface crack in tension we see.

Scenario 2) the area of deck north of the crack first becomes unsupported. The collapse is progressing from the north to the south. One or more of the columns along column line 14.1 between column line G.1 and K have punched through. The only remaining support for the parking deck is the connection to the wall and the deck is rotating downwards in the north. We know from sheet S12 of 14 (37 of 336) modified 1.17.80 to reflect change of pile type. That the typical retaining wall is 8” thick plus the concrete over the sheet pile, perhaps 16” total. The question becomes whether it is possible for the deck wall connection to offer sufficient resistance to downward rotation of the deck to the north to create the crack. In this scenario the stress is concentrated in the outside of the wall as the deck hinges on the front surface of the wall. The distance of unsupported deck from the hinge point to the north is at least 49 feet, the length of supporting concrete at the deck wall joint from the hinge point to the outside of the wall is 16 inches. The deck is only 9.5 inches thick but it has two pieces of rebar running horizontally the wall has one piece of rebar running vertically. The deck wall joint cannot offer sufficient resistance to the rotation of the deck to cause the crack we see. The deck wall connection would fail first, just as it did east of column line K. Scenario 2 is not a viable condition to produce the top surface crack in tension we see.

Since the area of deck south of the crack rotates down and the area of the deck north of the wall also rotates down, there must be a hinge point somewhere between the wall and the crack that allows the deck to retract from the wall.

Quote (Jeff Ostroff)

Tha area was never mentioned as a problem area prior to the collapse,
In your helpful video “Analysis Garage Video BEFORE Condo Collapse: Water Everywhere
From 9:50-15:20 including the important advice at 10:35 “If you don’t tell water where to go, it will make up it’s own mind and it always picks the most expensive course of action”. There is lots of evidence of water damage. And that area of deck underside is stepped down, meaning the water can flow from column line K to the west via capillary action.

Quote (Jeff Ostroff)

2) IF the slab separated from the south wall with cars on it, why did they fall back into the V-shape at the center of the slab (driving lane of the covered parking deck), instead of cars falling forward toward the south wall since the slab separated from the wall?

2) The deck cracked beneath the black pickup truck, its rear wheels dropped to the point the chassis bottomed out, column I14.1 punched through, column I14 punched through, other columns punched through, the deck impacted cars below and fractured [along the construction join?] between column lines 14 and 14.1. The cars didn’t move toward the south wall significantly because they were not between the crack and the wall and the angle of the deck was never steep enough to cause them to roll towards the wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SFCharlie)

The problem in my mind is, how was the energy of the collapse "stored" during the seven minutes between the deck and tower collapses?
I have imagined that the energy was stored as potential energy, with not all of the deck collapsing [as L to M did] adjacent to the building and part being left suspended [ I to L or I to K for example] and continuing to apply torque to the columns along the front of the building at column line 9.1.

Quote (SFCharlie)

What was going on during those seven minutes?
gradual rotational displacement of the columns along 9.1 until the tipping point was finally reached.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (FJBnomics)

However, if their parking spot was say in North East Corner near the East Stair Tower and I lived on first floor, I for one would take the stairs as the shortest direct path to my apartment/condo. Especially if justing getting back from a gym workout.

So it is possible they immediately turned left off entrance ramp? If 1st collapse was closer to elevator, perhaps they were not aware. I see in recent photos posted the deck delaminated at South Wall. Thus perhaps all that fell initially was the 3/4” concrete. cover below rebar grid?

You’re confusing the Nirs and the Vazquezes.

Sarah Nir and Gabe Nir did indeed park in Space 14 near the east stairwell when they arrived at around 12:30 AM. They have never stated explicitly that they used the staircase instead of the elevator to get to 111. But your theory does make sense.

Another person who also arrived at about that time and parked in the garage was Eric Zion, who had just dropped his wife off at the hotel where they were staying. I have never found an interview with him to state what space he parked in and whether he saw anything unusual in the garage before he went up to 508. He left before the collapse on his scooter. We do not know for sure whether he left from the lobby or the garage, but since his scooter was in the apartment I theorize it was from the lobby.

We do know for a fact that the Vazquezes used the elevator, even though we do not know which parking space they used or what route they walked to get to the elevator. They heard very loud cracking sounds just before they entered the elevator, and they were inside the elevator when the deck collapsed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

and to all of them it sounded like a single loud event,
This implies there was only one deck collapse event.

Quote (MaudSTL)

We can agree that surviving witnesses heard a loud crash that some of them assumed was a collapse.
A loud crash preceding the primary deck collapse event. This confirms the witnesses reported two events.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (IanCA)

A loud crash preceding the primary deck collapse event.

The witnesses perceived the loud crash at 1:10 AM as one event. The witnesses perceived the deck collapse at about 1:15 AM as one event. The witnesses perceived the building collapse at 1:22 AM as one event.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@MaudSTL, thank you very much for clarifying, we are completely in agreement on this aspect now.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

It may seem like a pedantic exercise to get the labels and time stamps proper, but it sure keeps things on track. Thanks Maud for your contributions.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

Sarah Nir and Gabe Nir did indeed park in Space 14 near the east stairwell when they arrived at around 12:30 AM. They have never stated explicitly that they used the staircase instead of the elevator to get to 111. But your theory does make sense.

Thanks MaudSTL for clarifying that.

Edit: Red Corona I agree with your post that 1:10am noise could have been as you cite, and yes I mixed up the two witness groups and events.

For those who can think outside of their own sandbox, it makes perfect sense, without 'stretching imagination', that 'perhaps' the first shedding of some concrete was related to first movements of slab as it sagged and retracted from South Wall. If I understood IanCA correctly and from looking at photos of South Privacy Wall, it appeared that Slab at wall extended 16" south from the inner edge of the northern side of the 8" concrete parking garage wall.

Perhaps there was a slight pause as slab retracted, and shed some layers of the lower concrete cover below rebar grid? This partisl shedding would seem logical, since the bottom edge of slab would be in tension in some places and in compression in others, due to the butterfly forming under parking deck near south wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@IanCA and @Sym P. le, You’re welcome.

It is unfortunate that the surviving witness statements do not contain directional clues that point to the location of the deck collapse trigger. The banging that went on for hours and the loud crash at 1:10 did not point to the deck for any of them. In 111 the bangs and loud crash seemed like they came from above. In the lobby the loud crash seemed like it came from the elevator (and no one has asked Shamoka Furman if she also heard the bangs that they were hearing in 111.) No one has ever asked Eric and Tamar Zion what they heard and saw when they used the garage earlier in the evening.

As for the deck collapse itself at about 1:15, it was apparently so fast, without any perceptible pauses, that the people on the first floor and across the street all perceived it as one single crash. Yet the loud sound of this crash is not what woke up Ileana Monteagudo in 611 (who said she was awakened by a “supernatural force”) or the late Cassie Stratton in 410 (who told her husband she woke up because the building was shaking.)

So the witness statements give us a timeline of major events and some general clues about what could possibly have been going on, but all the possible collapse triggers will have to be identified and ranked forensically. And this forum only has access publicly available information like photographs, so it’s frustratingly similar to reading tea leaves.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)


I agree with reading the tea leafs, and I do think that skill is a speciality gained long after the college basic broad ‘cook book’ foundation is poured.

Where I live, there is frequent DoD missile testing and explosions, perhaps 15 to 20 miles from my house, which is on slope of limestone mountain. The effects shake the ground and my house.

I know the direction the testing is coning from my house, yet I have a hard time pinpointing the direction of the incident sounds from the reflected sound waves At times, I would say it came from the mountain which is the opposite direction of the incident sound.

I am a OLD technical person, whereas the eyewitnesses most likely have never been exposed to this intensity of heavily reflected sounds in a concrete structure. Yes it was one event, but I see at least 4 distinct steps. Initial loss of concrete somewhere (likely parking deck slab), parking deck/patio deck collapse, middle building collapse, and East side collapse. The limited ‘witness’ information in public domain is not something that is freely released, especially after everybody lawyered up. In fact, once you lawyer up, ain’t nothing released without a specific agenda for that release.

The collapse was not a single event. It was a time phased event, and it happened very quickly from initial collapse sound. Popping, booms, creaks went on longer as parts of slab/columns progressively failed and transferred loads internally.

Time phased means variations in frequencies and intensities of incident and reflected sounds. So one event is not just one ‘boom’ that is quickly attenuated.

So for the layman witness to say the sound came from a certain direction is not necessarily the direction of the incident sound source. There will be lots of reflected sounds associated with original source and that will smear the perception.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (MaudSTL (Computer)20 Jun 22 04:12)

Yes Maud. Thank you very much!

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

> @FJB However, if their parking spot was say in North East Corner near the East Stair Tower and I lived on first floor, I for one would take the stairs as the shortest direct path to my apartment/condo

I think this was answered already, but I was talking about the Vazquezes (apologies if that wasn't clear) and we know they used the lift from their statements. So I don't think there's any reasonable way the garage could have been visibly seriously damaged and them not noticed.

Ed: And yes, big thanks to Maud for keeping us all on the straight and narrow wrt witness statements and the timeline!

Ed2: Regarding the "energy" for those 7 minutes, I think this is a mistaken concept. The energy of the building is in gravitational potential energy, mostly, and not really relevant until the collapse. What was happening for those 7 minutes is that stresses were being applied which were very slowly bending or crushing important things (K and L 9 columns) and redistributing stress as those columns lost their strength. It seems like they failed pretty much simultaneously.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red Corona)

What was happening for those 7 minutes is that stresses were being applied which were very slowly bending or crushing important things (K and L 9 columns) and redistributing stress as those columns lost their strength. It seems like they failed pretty much simultaneously.

Thanks, Red Corona. What you stated is compatible with witness statements.

Gabe Nir in 111 said he felt rumbling beneath his feet after the 1:10 crash and also after the deck collapsed at about 1:15. In a later interview, he also said that he felt the building sway after the deck collapsed. He didn’t say either of these things mention the swaying in any of his contemporaneous interviews, but rather months later, in the Miami Herald “House of Cards” feature. So I have always wondered whether he was asked leading questions looking for support of their collapse theory. But what he said is certainly compatible with the description of how the structure redistributed its load in the last seven minutes.

Up in 611, Ileana Monteagudo woke up after the deck collapsed at about 1:15 and found her sliding balcony door so out of square that it wouldn’t slide. Then she saw a crack form in one of her living room walls. We have never had confirmation of which wall cracked, but my theory, based on how the furniture was arranged in a real estate listing, is that it was the west wall. But that is just a theory. At any rate, within minutes of the deck collapse the redistribution of stresses had already changed the geometry of her unit. A few minutes later, the Ring camera video that triggered at 1:22 also showed a geometric change in progress.

Remember too that the late Cassie Stratton (410) told her husband the building was shaking and it woke her up. Since she called him at 1:20 from the balcony, the shaking must have woken her up sometime between 1:15 and 1:19. Just before the building collapsed at 1:22, she told him the building was shaking again. So the load transfers may have briefly paused before the columns finally buckled.

>>>>>Edit: See correction above. I conflated statements about rumbling and swaying, and have corrected my comments.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I believe the Ring cam triggered twice. We have an initial nine static frames immediately followed by a second fluid scene followed by a few dark frames. (At least in my copy)

Are two time steps available?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red Corona (Computer))



I think this was answered already, but I was talking about the Vazquezes (apologies if that wasn't clear) and we know they used the lift from their statements. So I don't think there's any reasonable way the garage could have been visibly seriously damaged and them not noticed.

Actually, it was late, they may have been tired or distracted - if their parking spot was near the elevator, it's unlikely that they were looking around much beyond right where they were driving. Plus, there's no reason for them to be looking up - so if the deck had started punching thru, they might not have noticed. How brightly lit was the garage (the cell phone shot down the ramp makes it look rather dim) and could initial damage to the deck have taken out any lights/wiring, making it even less likely they would have seen any damage? (Given the 'maintenance' or lack there of, a light or two being out probably wouldn't have raised any alarm.)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

My understanding (from the video walkthrough of the garage the year before, and various Youtubers who've visited CTN since the collapse) is that the garage was normally lit, and so the lights being out because of a deck collapse would be even more noticeable. The deck could have started punching through, yes (I suggest that in my previous post actually), but not to the extent of any visible ceiling collapse on the underside imo.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I reached out to Shamoka last week but she has not responded to me. I will be at the Remembrance 1 year memorial at the condo collapse site Friday. I hope to meet up with the sister of cassie, who had called her husband at about 1:20 AM to tell him the pool deck collapsed, went the building collapsed and she was killed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Jeff, I know that Shamoka is really struggling with PTSD, as are the other survivors. There are many questions for Shamoka listed in the Detailed Data tab of the Timeline, but I am not sure that this anniversary is a good time to ask her anything, as it would cause her to have to relive a deeply traumatic event.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Surfside building collapse: Security company to pay most of $1B settlement, attorneys say This is the first time I’ve seen in writing the claim that Securitas failed to train Security Guard Shamoka Furman to press the all-unit voice alarm. This story doesn’t mention the supervisory state of the alarm system, the lobby alarm switch being pulled, or any other details mentioned in the article about the security system log we have previously looked at.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Researcher Warns About Sea Level Rise Impacting Buildings Like Surfside Condo

As NIST conducts invasive testing, FIU researcher Randall Parkinson has published a paper in which he states that the ground water rose above the CTS basement level an average of 244 times a year between 1994 and 2006, and an average of 636 times a year between 2007 and 2020.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Drone video dated June 23, 2022 reveals location of invasive testing.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The judge just approved the one billion dollar settlement this morning after a hmorning after hearing. Here is the link to the AP story on it so this happens 1 day before the 1 year anniversary which was his goal originally. I will be down there at the site tomorrow for the festivities covering it.

https://news.yahoo.com/judge-approves-1b-deal-dead...

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

It’s certainly understandable that the survivors feel punished by the $1B wrongful death settlement.. The $96M settlement for loss of property won’t allow the survivors to buy a similar property. All the suffering is so sad. The recent photo of Ileana Monteagudo makes her look like a different person.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Linked video is a local station's story about the mother and daughter that survived falling on top of the rubble. The beginning recounts their actions and how they ended up where they did.

Link

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Thanks, @Debirlfan. This video has a novel animation that shows both the north side of CTS and unit 904, and also the interior of unit 904. I am still listening to it, but so far I haven’t heard anything that would cause a Timeline update.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

One Button Could Have ‘Saved More Lives’ in Florida Condo Collapse (this is an archived version, so no subscription required)

The NYT has the depositions and the security system logs, and we finally have an interview with a witness from 309 who actually saw the deck collapse in progress, collapsing from south to north. They also interviewed Shamoka Furman. There are some time stamps from the security log, including a Trouble code at 1:15:29, which may give us an accurate time for the deck collapse. The system logged a fire alarm at 1:15:46, which may be the lobby pull switch. If that’s the case, then Shamoka Furman is likely to have pulled it. Shamoka’s first 911 call was logged at 1:16:27. The 911 call from Central Alarm Control was logged at 1:16:39.

Here are highlights of the new information:
  • “…Paolo Longobardi (309) on the third floor. Thunder, he thought. But his wife, Anastasiya, had heard something more unsettling: an unnatural, metallic crunch. The two of them, groggy with sleep, peered out the sliding glass door of their bedroom overlooking the pool. Below them, the pool deck was caving in. “It was disappearing into the ground,” Mr. Longobardi said. “It was like a wave coming from the right to the left — from the south to the north — and it was falling.”” NOTE: A long time ago, one of the witnesses in the lobby (it may have been Chani Nir…I’ll see if I have it in my notes…) mentioned seeing a family escape…this may be that family.
  • Jonah Handler and Stacie Fang (1002,) having heard the “thunderous bang” of the deck collapse, went out on their balcony to see what had happened. They thought the sound was from above, but they looked up and didn’t see anything. So they went back inside to the bedroom, which is where they were when the building collapsed.
  • “Around that time, the building’s alarm system was starting to activate, first at 1:15:29 a.m., when it signaled “trouble,” according to a data log. Seventeen seconds later, a fire alarm triggered. It sent out an automated alert to a monitoring company, though it is not clear that it generated an audible alarm on any floor. Soon after, a staff member at the monitoring company notified 911 that a fire alarm had been activated at Champlain Towers.“
  • “The building also had a sophisticated audio warning system designed to broadcast an alert into the bedrooms of every unit. But it was never triggered, newly available deposition testimony and interviews show, because the security guard had never been trained about the system and the single button needed to activate it. “If I had known about it, I would have pressed it,” the security guard, Shamoka Furman, said in an interview.” “Ms. Furman, who had been a Champlain Towers security guard for four months, said in an interview that she received minimal training when she was hired, with another security guard explaining the contours of the job while they stood for an hour in the lobby. She said she never learned about the “all call” button. The other guard declined to comment.”
I will update the Timeline accordingly.

>>>>>Edit: I just caught another new detail. As Ileana Monteagudo (611) left, she apparently turned off the light. “being careful to turn off the lights behind her.”

>>>>>Edit: I can’t tell what woke up the Longobardis (“thunder”) in enough time to get out of bed, get to the window, and look out to see the deck collapse in progress. Could it have been the loud crash at 1:10 that we know Shamoka Furman heard in the lobby and the Nirs heard in 111? The Longobardis describe the actual deck collapse as sounding like “an unnatural, metallic crunch.” So what did Jonah Handler and his late mom Stacie Fang hear that made them go out to their balcony? They thought it came from above, and Jonah didn’t mention hearing car alarms, as Ileana Monteagudo did, even though she didn’t hear the deck collapse itself other than as a “supernatural force” that woke her up. Is it also possible that Jonah and his late mom heard the loud crash at 1:10, went inside 1002, and didn’t even hear the deck collapse from that side of the building? After all, the Gonzalezes didn’t hear the deck collapse in 904…it was the shaking of the building that got them going.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

MaudSTL I noticed on that drone video of invasive testing they show several very large square holes where they have cut out the foundation for very invasive tests on the garage floor/foundation slab. Several large square holes have been cut.


I noticed that 3 large cuts appear around the M9.1/M10.1 area columns, with cutouts completely engulfing these 3 columns, each i=one in the center of its own cutout. Here are the 3 columns:

1) M9.1/10 column for Space #27.
2) L9.1/10 column for Space #77
3) L11.1 column that divides spaces 77/76

As you might recall from my videos last July, I had stated that either M11.1 or L11.1 was the first column to fail, and showed that on my chart of the garage mapped with puddles that I found on Fiorella's garage walk-through video.

I find it interesting that NIST chose these 3 columns to start the invasive testing, and many times in the past when they were still on site, I always saw them in groups huddled around M11.1 and M9.1/10.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Just heard the 911 call on Building Integrity's latest video - the security guard sounds like an idiot. I don't even know how the 911 operator was going to make sense of the call. And didn't pull the pull stations. Great communication.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I am here at the sight of the Champlain tower's South condo collapse today for the memorial it's going to start momentarily. Here are a couple of photos I just shot of what the site looks like today and what they have going on here. In one of my photos you can see I zoom in to where they started the advasive testing on the floor with the squares around the 3 columns that I mentioned last night. Also they started cutting long rectangular holes in the South wall.

Security here is off the charts just to get into the property itself my camera bag was checked twice by 2 separate secret service agents commanders dozens and dozens of cops here there's probably at least 4 dozen media tents and trucks and trucks and live towers set up I'm in a pool area back here What about a 100 other media people.




RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17


I am sitting next to the pool now during the remembrance event. There is one view of the Eastern most column of the pool wall in case you're still looking for photos near the pool wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (stcbus)

Blah blah blah

Please read this thread to educate yourself.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Read all of the threads. Doesn't change the fact how they sound on the actual call audio. Didn't even provide a full address or really answer any questions.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Maudstl )

“It was like a wave coming from the right to the left — from the south to the north — and it was falling.””
That is new info. Seems to imply the deck collapse started at or near the perimeter wall since that is the south end.
Also implies the deck didn't drop in unison for there to be a noticeable wave.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@stcbus, if you’ve read the thread, then you would know about Shamoka Furman’s activities.

Timeline
  • 01:10 A loud crash in the lobby sounds like it came from the elevator shaft.
  • 01:15:29 The fire alarm system logs Trouble as the deck collapses loudly, followed by rumbling.
  • 01:15:49 The pull switch in the lobby is activated and the system logs Fire, which triggers the monitoring system.
  • 01:16:27 Aborted 911 call with yelling in background. NOTE: This is the call Josh Porter chose to feature in his video.
  • 01:16:39 Central Alarm Control calls 911.
  • 01:17:06 Aborted 911 call.
  • 01:17:34 Aborted 911 call.
  • 01:17:49 911 call to report the emergency and the address. NOTE: Josh Porter chose NOT to use this call in his video.
  • >01:17:49 Makes calls to individual residents to tell them to evacuate.
  • 01:22 Building collapses.
  • 01:26 Helps Ileana Monteagudo (611) and a family of four escape from the garage.
  • 01:28 Presents herself to assist the police.

>>>>>Edit: Here is the 1:17:49 911 call via the Miami Herald.<<<<<<

Discussion

Fire alarm system log and monitoring 01:15:29-01:16:39:
01:15:29 Logs Trouble. This is probably when the deck collapsed. In the lobby, it was a very loud crash followed by rumbling, dust, and car alarms. All they could see from the lobby was cars sticking up out of an “abyss.”
01:15:46 Logs Fire from the activation of the lobby pull switch. Josh claims Shamoka failed to activate it, but she is the only person who could have done so. This is the alarm that triggered monitoring to call 911.
01:16:39 Central Alarm Control calls 911.

Four 911 calls 01:16:27-01:17:49:
Josh deliberately chose to scapegoat Shamoka Furman by not using the 911 call at 01:17:49, wherein Shamoka provides an accurate address and description of the emergency. This is after three aborted 911 calls (01:16:27, 01:17:06, and 01:17:34) where we can hear panicky residents screaming conflicting instructions at her as she tried to get the correct address. The Nirs were telling her to call it an earthquake. Shamoka called it an explosion downward. No one knew what had happened.

Calls to residents 1:18-1:22:
After activating the fire alarm at 01:15:46 and making the 911 calls at 01:16:27, 01:17:06, 01:17:34, and 01:17:49, Shamoka Furman starts calling individual residents to tell them to evacuate.

Building collapses at 1:22:
The north part of the lobby, not far from the security desk, collapses into the garage. Shamoka is only a few feet away from the collapse, and the darkened lobby is filled with dust and acrid smells. The front door is locked for lack of power. She has no idea what has happened.

Escapes and guides survivors 1:22-1:27:
Shamoka tries to escape through the valet window, but the porte-cochere has collapsed and is blocking her way. She re-enters the lobby and exits to find the the collapsed deck. Climbing down to the garage level, she encounters Ileana Monteagudo (611) and helps her climb out at 01:26. Shamoka then encounters a family of four and helps them escape from the garage level.

Assists police 1:28:
Shamoka climbs out of the garage and presents herself to assist the police at 1:28. Her injuries include cracked ribs and bruises; she has to use crutches in the following days.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Reverse_Bias)

Also implies the deck didn't drop in unison for there to be a noticeable wave.

Isn’t that how fast punching shear progresses? To the ear, it could sound like one big crash even though to the eye is progresses like a wave.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

There is some new information there. Thanks for the link Maud. We should be careful about taking statements that may have been given some time after the event as being accurate in every detail, however:

- 611 did turn off her light, that explains that. Still no-one's asked her which wall the crack was in though!
- Multiple statements that there was no audible alarm (or visible strobe? you'd think 611 would have mentioned that if it was going when she left her apartment)
- Confirmation that the all call didn't happen because it was manually operated and that didn't happen
- 309 - that "wave from south to north" testimony is, imo, also compatible with an initial collapse at K14.1 - that would have propagated to the south wall by the time they got to the balcony, and the main effect would still be a northwards propagation towards the building. But I don't think it's compatible with a collapse initiating around M11.1 as we originally thought.

Re invasive testing:

- Yes it is interesting that they chose to test columns around L/M 9.1-11.1. Those columns certainly played an important role in the collapse sequence. That doesn't necessarily mean NIST think it started there though.

Quote (Reverse_Bias)

Also implies the deck didn't drop in unison for there to be a noticeable wave.
Yes, that is expected for propagating punching through (or any kind of failure propagation really). There would be continuous noise over a few seconds as it happened.

That does bring me back to how interesting it is that stacks K and L seem to fail simultaneously - as if the deck pulls away that support beam or something as a single action that puts them both into failure as part of the same event.

Ed: Also watched Building Integrity's video but there's not any new information there, it's just a sum-up. Though I do agree (and I see you waded into the cesspit of Youtube comments to say so there as well) that his selection of 911 call audio is unfair.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17


Quote (MaudSTL)

Isn’t that how fast punching shear progresses? To the ear, it could sound like one big crash even though to the eye is progresses like a wave.
Yes as I've been assuming that but none of the witnesses really gave a good indication. 309 would have had a pretty good view of the k line planters and everything east. Maybe the edge of the parking deck also if they went out on their balcony, which it doesn't sound like they did. Wondering how they didn't give a public statement for a year.


Quote (Red Corona )

Yes, that is expected for propagating punching through (or any kind of failure propagation really). There would be continuous noise over a few seconds as it happened.

That does bring me back to how interesting it is that stacks K and L seem to fail simultaneously - as if the deck pulls away that support beam or something as a single action that puts them both into failure as part of the same event.
IKLM fell almost at exactly the same time, at least on the floors visible in the video. That does make the initiation point hard to pinpoint. Maybe the drop beam was still connecting them causing them to move as one?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Ok I’ll give the extra call. However every second and minute counted and it was just irresponsible to not complete the call. And I’m unsure about her doing the pull station because I thought that was half the reason the firm paid so much? Or she didn’t pull it properly where it handles the entire building (or a voice announcement). Not that it’s actually her fault the building fell, but I still expect more competence from an employee tasked with safety. Everyone should.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17


Quote (stcbus)

Ok I’ll give the extra call. However every second and minute counted and it was just irresponsible to not complete the call. And I’m unsure about her doing the pull station because I thought that was half the reason the firm paid so much? Or she didn’t pull it properly where it handles the entire building (or a voice announcement). Not that it’s actually her fault the building fell, but I still expect more competence from an employee tasked with safety. Everyone should.

1) It is quite difficult to complete a call with others yelling conflicting information. No one knew at the time if it was an explosion or earthquake or something else.
2) Pull stations don't have the capability to select "all call".
3) No employee should be expected to perform above the level of their training. Securitas paid because they neglected to provide that training.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red_Corona)

- 611 did turn off her light, that explains that. Still no-one's asked her which wall the crack was in though!
You’re right. I have seen nothing to tell us which wall cracked.

Quote:

- Multiple statements that there was no audible alarm (or visible strobe? you'd think 611 would have mentioned that if it was going when she left her apartment)
There is actually an explicit comment in one of the recent interviews where Ileana Monteagudo says the sixth floor hallway was perfectly silent when she exited her apartment, as if the building was vacant. She paused to knock on her neighbor’s door and got no response. Then she proceeded to the staircase.

>>>>>Edit: From the NYT “One Button” piece:

“Out in the hallway, Ms. Monteagudo, who had moved into the complex six months earlier, was struck by how quiet things were. She assumed that the units around her were largely vacant. There was no alarm.

“There was silence,” she said. “There was no movement. Nothing. I thought the building was empty.”“<<<<<

Quote:

- Confirmation that the all call didn't happen because it was manually operated and that didn't happen
Yes, it was a separate button that she was unaware of. Apparently her training back in February consisted of a one-hour stand-up orientation by another security guard who remains unnamed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Here's a pool picture I shot yesterday at the one-year anniversary of the Champlain towers South condo collapse remembrance. Interesting shot of the pool you'll notice the two giant square holes to the left of the O.1 column marking on the wall where they've already started the invasive testing. I'm working on the video for all of this and there are so many holes everywhere that they have started to slice and dice all over the property.

Core Samples were taken from H-BEAM!

For the invasive testing, they've already created a whole bunch of round core sample holes in the H-beam! They've also put numerous core sample holes on the wall of the garage ramp. And there are several square holes cut out of the South wall and the north wall of the property. You'll see all of my close-up detail photos once I have the video done hopefully tomorrow night.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Oh great now they're taking core samples, after it's been sitting out rotting for a year. Glad to see they're doing a thorough scientific bureaucratic investigation.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Reverse Bias)

Oh great now they're taking core samples, after it's been sitting out rotting for a year. Glad to see they're doing a thorough scientific bureaucratic investigation.

It's all about the 'Political' Science! soapbox

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I notice from Jeff's picture above that a large portion of the western end of the south wall has also been removed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Red_Corona)

Ed: Also watched Building Integrity's video but there's not any new information there, it's just a sum-up. Though I do agree (and I see you waded into the cesspit of Youtube comments to say so there as well) that his selection of 911 call audio is unfair.

I see Josh Porter’s use of Security Guard Shamoka Furman’s aborted first 911 call and his associated comments as worse than unfair; it’s downright dangerous. Anyone who has seen any of her video interviews knows that Shamoka, like all the survivors, has PTSD. PTSD increases the likelihood of health issues and suicide, especially in women. To add public humiliation to the burden of PTSD is cruel and unconscionable.

Josh Porter needs to take that video down and correct the misinformation in it that has triggered hate speech in his channel. I hope he has the decency to do it before Shamoka sees it, or he’ll need a new name for his YouTube channel, like Building Damage or Building Harm or Building Liability…or maybe just Punching Down.

Sorry…I had to get that off my chest. What he did is truly outrageous.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

People need to keep in mind nobody new the building was about to collapse or how long it would be until it collapsed. That's 20/20 hindsight.

A lot of people would have taken more than 7 minutes to get out. The fire alarm in my building went off a few weeks back in the middle of the night and I was one of the first out about 6 minutes later. People don't treat it like it's certain death. They try to sleep through it assuming it will stop, then gather their phone, keys, pets, change clothes ect.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

sgw1009, the red box you showed on my photo, the site was like that in September 2021 already long before they started invasive testing.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (sgw1009)

I notice from Jeff's picture above that a large portion of the western end of the south wall has also been removed.
Yes, you are correct.

Quote (Jeff Ostroff)

the site was like that in September 2021 already long before they started invasive testing.
No, I'm sorry that is incorrect. For example, please refer to your video that premiered on Nov 6, 2021 (video recorded Oct 26, 2021).
Link

Please count the wall sections West of the pool.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Yes, Sections M and L are missing.

Here is my photo from March 19, when they were still there.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I'll be premiering my video tonight showing all of the close-ups and numerous photographs that I shot at the Champlain towers site on Friday, where we were given access to the site itself due to the remembrance ceremony that they had. But here's a sneak peek of one of my screenshots from the video showing all of the holes drilled right around the pool and the column number 37, look at the top of the South wall where they have taken numerous core samples and then sliced off a few entire panels of the wall.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Friends, I am working on Witness Statement Timeline updates resulting from all the articles published because of the one-year anniversary. We have already discussed everything here that I plan to add.

Unless anyone has strong objections, I have decided to incorporate the few timestamps we have from the fire alarm system log into the High Level Sequence tab and the Detailed Data tab, even though they are not witness statements per se. I think that if I separate them into their own tab, it will just be more confusing.

I am also thinking about updating the High Level Sequence tab to include the Zions, who are currently mentioned only in the Detailed Data tab. I didn’t include them in that tab previously because they had nothing to report. However, in the last year no one has interviewed them to see if that’s really the case. So I am thinking the High Level Sequence tab would be improved by being more comprehensive. Therefore I plan to add the Zions and also the mysterious Woman with a Suitcase mentioned long ago in the ESPN piece.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Jeff Ostroff)

Here is my photo from March 19, when they were still there.
Thank you for finding and sharing that Jeff, much appreciated.

Quote (Jeff Ostroff)

I'll be premiering my video tonight showing all of the close-ups and numerous photographs that I shot at the Champlain towers site on Friday
Thank you.

Quote (MaudSTL)

Friends, I am working on Witness Statement Timeline updates resulting from all the articles published because of the one-year anniversary
Thank you MaudSTL, I support your suggested changes.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

Unless anyone has strong objections, I have decided to incorporate the few timestamps we have from the fire alarm system log into the High Level Sequence tab and the Detailed Data tab...

I do have a question on your post from 24 Jun 22 19:01:

Quote ("01:15:49 The pull switch in the lobby is activated and the system logs Fire, which triggers the monitoring system.")

We have long believed that sprinkler water flow was the first trigger for the fire alarm system. I wasn't sure if it had been confirmed that the lobby pull station was activated and not a water flow switch. Are we relying on the news media accurately disseminating information from the fire alarm log?
I haven't seen any information on the timing of any water flow activation, which seems strange. It is also possible that, since sprinkler pipes are often made from steel pipes and fittings and not cast iron pipes, that they may have bent and not broken. Therefore, there may not have been any water flow in the sprinkler system until the main building collapse.

Edit: Right after I posted that I realized it is very unlikely that those pipes would bend without knocking off a few sprinkler heads so it is even more puzzling why there was no water flow reported.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Therefore, there may not have been any water flow in the sprinkler system until the main building collapse.
There was a pipe gushing and swinging around in the Tiktok video that a few people said was probably a sprinkler pipe.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL (Computer) 24 Jun 22 01:51)

One Button Could Have ‘Saved More Lives’ in Florida Condo Collapse (this is an archived version, so no subscription required)

Given the latest eyewitness account from Paolo Longobardi (309) on the third floor, “It was like a wave coming from the right to the left — from the south to the north — and it was falling.” The south perimeter wall is again brought into question.

Given that the Longobardi's were awakened by "... something more unsettling: an unnatural, metallic crunch.", had the lobby parking already collapsed before they reached their balcony so that they only witnessed the balance of the south pool deck advance from south to north? There are alway more questions.

With Jeff's new pan of the south wall, I've done a collage using screen shots to compare the shadowing with the Allyn Kilsheimer images referenced some time ago. Attached is a full scale jpg.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948)

Are we relying on the news media accurately disseminating information from the fire alarm log?

The time stamps and other fire alarm system info come from multiple sources that include an industry rag and two news orgs. The first two feature the same forensic alarm pro. You will see that there’s inconsistency in the issue of the lobby pull switch vs. sprinkler question that I just picked by doing this updating exercise. Jeffrey Zwirn, the Miami Herald, and the NYT all have the alarm system log.
1. Life-Safety Lessons Learned From the Miami Condo Collapse by Jeffrey Zwirn, Feb. 2, 2022
  • “Prior to the catastrophe, Champlain Towers had contracted with an alarm contractor that replaced the existing building fire alarm system with a new voice evacuation fire alarm system. Among other things, it included common-area smoke detectors, manual pull stations, voice evacuation speakers inside each of the apartments and in the common areas throughout the premises, and a remote alarm annunciator located in proximity to the 24-hour guard station in the lobby.”
  • “It appears that a manual fire alarm pull station in the lobby of the building was activated before the collapse. Against the foregoing backdrop, issues surrounding liability have arisen due to myriad reports that persons who were able to get out of the building and escape before it collapsed never heard the building fire alarm system activating through its voice evacuation function.”
  • “Preliminary forensic examination of the central station’s account history report reveals that prior to the building collapse, the fire alarm system was in trouble, and a supervisory condition existed. The underpinnings of what part(s) of the fire alarm system was not functioning correctly and why it had not been restored to a functional mode through performing service on the system is continuing forensically.”
‘2. Lives would have been saved’: Fire alarm didn’t go off before Surfside tower collapse June 27, 2022
  • “The Herald exclusively obtained a “customer activity report” for Champlain Towers’ alarm system. It shows that a fire alarm signal was recorded at 1:15 a.m. and that the building’s alarm monitoring company, Central Alarm Control, called 911 soon after. The initial triggering of the alarm system should have set off loud alarms in the entire tower, said Jeffrey Zwirn, a forensic alarm expert who reviewed the report and records about Champlain Towers’ fire system. Zwirn said that the collapse of the pool deck — which video shows ripped open pipes — would have automatically activated the alarm system when it damaged the sprinkler system. “That should then have triggered a voice-evacuation alarm in every unit,” Zwirn said, adding that the system may have been improperly programmed.”
  • “Hallandale Beach-based Premier Fire Alarms and Integration Systems installed the system in 2017.”
  • “Police body-camera footage from several minutes after the tower collapsed appears to show a strobing light going off in the lobby and another in the garage. Albert Aguero said that flashing lights on fire alarms and exit signs helped him and his family navigate their way out of the building after the collapse. But the devices never produced sounds…
  • In 2020, “Champlain Towers’ management emailed residents that a recent false alarm in the middle of the night was caused by “a faulty pull station located in the lobby area.””
  • “When the pool deck collapsed, resident Sara Nir was in the building lobby. Panicked, she told the security guard to activate a pull station. It’s not clear if that pull station was the same one that had malfunctioned the year before. The customer activity report shows only one fire alarm signal going to the alarm company — and there’s no indication whether that signal came from the pull station or from the sprinkler system in the garage.
3. One Button Could Have ‘Saved More Lives’ in Florida Condo Collapse June 23, 2022
  • “The building also had a sophisticated audio warning system designed to broadcast an alert into the bedrooms of every unit. But it was never triggered, newly available deposition testimony and interviews show, because the security guard had never been trained about the system and the single button needed to activate it.“
  • After the deck collapsed, “…the building’s alarm system was starting to activate, first at 1:15:29 a.m., when it signaled “trouble,” according to a data log. Seventeen seconds later, a fire alarm triggered. It sent out an automated alert to a monitoring company, though it is not clear that it generated an audible alarm on any floor. Soon after, a staff member at the monitoring company notified 911 that a fire alarm had been activated at Champlain Towers.” NOTE from Maud: I calculated the time of the Fire alarm at 1:32. The time of Shamoka’s 911 calls and the Central Alarm Control call came from the 911 call log.
>>>>>Edit: I personally believe the lobby pull switch wasn’t working, but that Shamoka pulled it on orders from Sara Nir. I mean, if you had Sara Nir barking orders at you, you would pull the switch too. I think that the Fire alarm that got logged came from the garage after the Trouble code got logged. But I would like your thoughts on this interpretation.<<<<<

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. Le)

Given that the Lontobaridi's were awakened by "... something more unsettling: an unnatural, metallic crunch.", had the lobby parking already collapsed before they reached their balcony so that they only witnessed the balance of the south pool deck advance from south to north?

The article says that they watched the deck collapse from their window after having been awakened by a sound like thunder. I think what woke them up was the loud crash at 1:10. That would give them time to go WTF, get out of bed, and go to the window in time for the metallic crunch and the progressive collapse.

If the metallic crunch had gotten them out of bed, the deck would already have been collapsed by the time they got to the window.

>>>>>Edit: The weird part to me is the metallic crunch. Everyone else calls it a very loud crash. This is the first time we’re hearing metallic crunch.<<<<<

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Longobardi's vantage point from their deck in front of their bedroom sliding door, unit #309.

Edit: Just to be clearer, the master bedroom is at the south end of the unit so I moved the arrow.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Oh wow. Metallic crunch could be the cars crushing each other. I was once a service director at a car dealership, and we would rejoice at the metallic crunch of fender benders because it meant work for the body shop.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Reverse_Bias)

...a few people said was probably a sprinkler pipe.

Are you gonna believe what "a few people say" or make up your own mind based on what is easily observed. I believe that was a drain pipe based on its size and low pressure flow rate and direction of flow in the tiktok video. The largest sprinkler pipe in that area was a 2". It was fed with a loop system and would have flowed from both directions @ 170psi. The fire pump should have been running at that time (if there was a broken sprinkler) and puts out 750 gpm. The water in the tiktok video did not flow like a broken sprinkler pipe.

I could be wrong.
Tell me what you think.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL (Computer) 28 Jun 22 02:21)

The weird part to me is the metallic crunch.


Quote (From the article)


Thunder, he thought. But his wife, Anastasiya, had heard something more unsettling: an unnatural, metallic crunch.

The two of them, groggy with sleep, peered out the sliding glass door of their bedroom overlooking the pool. Below them, the pool deck was caving in.

... so they didn't even make it out on to their deck but I read the awakening as "he heard thunder, she heard metallic crunching." Then they looked and he saw the pool deck caving in from south to north.

If they were not on their deck and she heard metallic crunching, they weren't in a position to witness the lobby parking visually. That suggests the lobby parking area went first, followed by the pool deck.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948 (Electrical) 28 Jun 22 02:31)


An isolated zone of sprinkler piping back draining is the most logical explanation to me. What would a drain pipe be draining?

Edit: Although sprinkler system back flow could be rather discolored, not appearing so white.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

That suggests the lobby parking area went first, followed by the pool deck.

I certainly agree, because that’s always been my theory. But I’m an analyst so my opinion doesn’t count. Let’s see what everyone else says.

>>>>>Edit: one thing you learn when you fly in hot air balloons is how well sound travels upward. This couple was perfectly positioned above the action, so the metallic crunch, which is higher frequency than the crashing, would have traveled to them very clearly. I doubt there was any significant delay between the car park collapse and the wave from the south, just based on my understanding of punching shear failures.<<<<<

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

A quick study suggests it would be generous to say they had a complete view of even the pool deck.

Edit: full scale attached below It won't attach with edit





RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

Thanks for your response, it cleared up some things for me.
The lobby would have a pull station at each exit, one at the front door, one at the exit to the pool area, and one at the service ramp on the north side.
Most pull stations just have a simple toggle switch, either on or off. This was an addressable system so all initiating devices like pull stations and smoke detectors would also have a small electronic module to identify the device at the control panel. The panel polls the devices to check their status. Either activated or not activated. If the panel does not get a response from a device it logs a trouble code for that device. So if it was not working it should show up in the fire alarm log.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Nukeman948, so we are saying there would be no pull switch at the security desk? As a civilian, that surprises me because I would have imagined the security desk would have all the controls.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

@Sym P. le, I would have thought they could have a wider view from that vantage point.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le)

An isolated zone of sprinkler piping back draining is the most logical explanation to me.

Why would the sprinkler system be isolated?
Why wouldn't it flow from both directions if it was a sprinkler pipe?
It could have been a domestic water supply pipe. I don't know and it doesn't matter.
None of this has anything to do with the original point I was making that there may not have been flow in the sprinkler pipes, but Maud's post that came after mine seems to have cleared that up.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL (Computer) 28 Jun 22 03:13)

I would have thought they could have a wider view from that vantage point.

Likewise, until I sketched it out. The edge of the balcony creates a greater obstruction for someone standing inside the unit than I thought.

Had they moved out onto the balcony, they would have had a much better vantage point however it doesn't seem like time was available for that to happen and in their minds, they had all the information they needed to tell them to get out.

Edit: Perhaps the take away is that they could see enough of the pool deck to see what was going on but they couldn't see the parking area directly beneath them unless they moved out onto the balcony.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (MaudSTL)

so we are saying there would be no pull switch at the security desk?


The security desk is where the fire alarm annunciator panel was and it has a switch built in so there is no need for a separate switch. It would also have lights or a read out to show which zone had an alarm activation and the address of the device.
It is also where the "all call switch" was located along with the microphone to give voice directions to evacuate.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Is the punchout pattern around column 72/73 indicative of a directional wave of failure? i.e. The typical wedge of concrete on the south and west sides of the slab/column connection may indicate a zone where typical bending failure occurred while a wave of failure spreading to the northeast caused the slab to shear off the column vertically on the north and east sides.

Edit: ... which may bring us back to the big heavy truck parked southwest of that column.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Nukeman948 (Electrical) 28 Jun 22 03:21)

It could have been a domestic water supply pipe.

Yes. Now you're making sense. Backflow of domestic water?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (SymP.le)

Likewise, until I sketched it out. The edge of the balcony creates a greater obstruction for someone standing inside the unit than I thought.

Remember the deck started 6ft higher up.
Hindsight 20/20 if they had walked on the balcony with their phones and shot a 20 second video of the deck and the edge of the building before it collapsed we might know the cause of the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

If the security cameras were on around the pool deck, we would have more answers as well. Maybe they were and the investigators already have the info. I can't imagine turning on my phone cam that fast myself.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Longobardi's potential view to the south is much more directly down so I've indicated a potential footprint of view accordingly.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I am trying to visualize how this would work. So if the planter/parking deck fell with the sound of thunder, are you saying that could have pulled the deck off the south wall and resulted in the south-to-north wave?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I was just trying to gain some appreciation for the witnesses proximity and vantage point. It would seem the Longobardi's are the best witnesses to date and that gives a lot of weight to their statements. At the end of the day, all of the evidence should be telling the same story. As "investigators" we are the ones who have to challenge our thoughts and preconceptions to figure out what that story is.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

IanCA, who are these people???

🥸

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (FJBnomics)

IanCA, who are these people???
It is difficult to tell at times. I think they may be using pseudonyms.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

No matter who the pseudonyms are, please carry on!!!

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

(OP)

Quote (FJBnomics (Military)28 Jun 22 14:24)

IanCA, who are these people???
If you are referring to the people in the NewYorkTimes article, they are Anastasiya | Paolo Longobardi. At least one major network has confused them with another family of four, but a google picture search will reveal:
[img https://res.cloudinary.com/engineering-com/image/u...]

Quote (NYTimes.com)

It was like a wave coming from the right to the left… from the south to the north
The loud noise that brought Jonah and Ms. Fang to their balcony in the initial stages of the disaster also awakened Paolo Longobardi on the third floor. Thunder, he thought. But his wife, Anastasiya, had heard something more unsettling: an unnatural, metallic crunch.
The two of them, groggy with sleep, peered out the sliding glass door of their bedroom overlooking the pool. Below them, the pool deck was caving in.
“It was disappearing into the ground,” Mr. Longobardi said. “It was like a wave coming from the right to the left — from the south to the north — and it was falling.”
As he watched the pool deck collapse from Unit 309, Mr. Longobardi, a civil engineer who builds bridges for a living, thought a huge sinkhole might be swallowing the parking garage beneath the deck.
“We decided to run,” he said.
The Longobardis woke up their two children, ages 14 and 9, and ushered them out the door. Mr. Longobardi said one of the children recalled hearing an alarm during the escape.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The owners of 309 are listed as Nelson A Fonseca (Husband) and Myriam B Fonseca (Wife). If I found the right one, Nelson is CEO of an IT company in Coral Gables, so they are renting 309 to the Longobardis. https://cdn.theorg.com/fe0b9df1-7c74-46df-a5f0-d9c...

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P. le (Mechanical))

Is the punchout pattern around column 72/73 indicative of a directional wave of failure?

One of the puzzlements in the photo of that punch out is the way the broken stampcrete at the column ended up. Not to hijack any thought process on the actual slab. I just can't get my head around how the stampcrete passed over or around the bars and ended up so neatly in the front print of where they began. And then compound that with the appearance the the large piece seems as though it was under the rear end of car the whole time. There is an explanation of course. I just can't imagine it.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (zebraso (Mechanical) 28 Jun 22 20:41)

how the stampcrete passed over or around the bars and ended up so neatly in the front print of where they began.

It's all rather magical isn't it. And the clean top bars.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Problem is "magic" is not how we should chalk it up. Anyways, I meant to say footprint and not front print. Must have been auto correct or some other voodoo.

Edit: I think it may have happened that the right rear under side of the bumper would have rotated the stampcrete clockwise over the top bars as it slid downward. Then after it passed the bars the car bumper would have pushed it down under the bars and it fell right back into the hole it came out of. Sorry, I just have to try to make sense where there is none. I just don't know why it took so long to figure out anything plausible. The clean looking bars are probably more concerning then.

Edit: dang I meant left rear. I'm looking at it like a CT scan I guess. (joke)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I would like to reintroduce the image that MaudSTL contributed to back in February.

Quote (MaudSTL (Computer)5 Feb 22 01:49)

I’ve mapped the narrative onto IanCA’s annotated drawing for the sake of discussion.

I think it is relevant in light of the recently publicized witness statements from appt 309.

The only thing I would adjust now is to suggest that the loud crash heard at 1:10AM could be a portion of the deck/planter base falling into the garage.

If the deck collapse is progressing from the south to the north this suggests the deck collapse started at or near the southern wall. Other evidence, such as the shape of the collapsed decks and the dust on the column, suggests that the parking deck collapsed before the pool deck.

Quote (Sym P. le)

Longobardi's potential view to the south is much more directly down so I've indicated a potential footprint of view accordingly.

Thanks very much for the helpful images. Another factor I have in mind is that they may well have seen the dust to the south, to their right, because it was clearly reported by other witnesses before the main building collapsed. If they could see a dust cloud to their right and then observed the deck collapsing in front of them and progressing to the left I think that would reinforce their perception of the event and fit well with their reported statements.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Unfortunately, basic physics xnays that theory without additional support and once again, that planter is not likely to have the degree of influence that you imagine. It is far more likely that vehicle traffic caused deterioration at the column interface, which suffers from a lack of rebar.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Quote (Sym P le)

Support needed here

We are talking a 2-way reinforced rebar grid slab, and more significant deterioration of structural slab under planters, due to no water proofing membrane under stamped concrete with edge of stamped concrete butting up to Southside planter wall. Then add pool exhaust chemicals mixing in plants and planter soil.

So if slab under planters deteriorated more, it is logical their loss of strength could affect that area more, leaving a cantilevered slab to the North, that at that moment has the N-S grid loads fully transferred to the less deteriorated E-W grid at the point where support is needed that would cause tension break in top of stamped concrete and structural slab.

Seems to fit well within the laws of Physics. Support does not have to be a wall or column directly under break, at a given second or millisecond.

Note E-W rebar grid held longer to West and was unzipped to the West, which is evidence of support provided to cause tension crack in top of slab.

Edit: It also appeared to me in photos, that there was no consistent laying of N-S rebar under E-W rebar. Sometimes it appeared E-W was bottom grid. This would seem to affect how loads transferred, based upon a given initial failure point?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

I've always understood the laws of physics (mechanics of materials) to be the same regardless 8000 psi concrete or a wet sponge.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

The other thought is all the flexing of the elevated parking deck has added weakness in specific locations based upon loading of that area, and slab deterioration in that area. So we do not have uniform structural properties in the reinforced concrete structure, which is an unknown variable in equation.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 17

Yes but no matter how weak the concrete system is, in order for a downward force to break it, there have to be a reacting supports or the system will merely rotate.

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