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Miami Beach, Champlain Towers South apartment building collapse, Part 04
49

Miami Beach, Champlain Towers South apartment building collapse, Part 04

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (GPR_Tech (Civil/Environmental) 7 Jul 21 15:22 Any thoughts on the NYT article? See related DWG's that I could find for the SOUTH [not north)

Towers S.6 Second Floor Framing Plan (Pg.28 of 336) & (Pg.110 of 336) Typical Notes #5 at least 25% of all column strip reinf. shall be centered over the column as explained in typ. flat plate det. - see sheet S.11]

What I would say about this is that the original plans are so sloppy that its impossible to be certain of the slab reinforcement that was required at each of the columns. 25% of the "column strip reinforcement" is a very poor way to call this out in the plans and highly prone to an incorrect interpretation by the contractor. I'm sure someone will comment that this is common practice, however it is not best practice.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

What I see in this photo is that one of the top bars was installed just outside the column cage. So when the slab yanked down on that side of the column, the bar acted like a wire cutter and helped shear the slab off at the column face, rather than remaining within the column cage and providing some catenary support.

The image resolution isn't great, so I could be wrong about the column tie.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (tmwaits1 (Structural)7 Jul 21 15:42)


What I think we are missing is, we do not have a copy of the "SHOP Drawings" and those are what would have been used by the contractor to fabricate the building.
We only have a mixed up copy of the Design Drawings.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

OK why two different length top bars .30 L1/L2 & .25 L1/L2... or WHAT IS THIS TELLING US?
(I just do not know what this detail would look like)
S.11 (Pg. 38 of 336)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (GPR_Tech (Civil/Environmental) 7 Jul 21 16:55 Quote (tmwaits1 (Structural)7 Jul 21 15:42) What I think we are missing is, we do not have a copy of the "SHOP Drawings" and those are what would have been used by the contractor to fabricate the building. We only have a mixed up copy of the Design Drawings. )


The reinforcement we are talking about should be fully detailed in the plans. For this reason, shop drawings would not be required unless this submittal to the EOR is specifically noted as required in the general notes. I don't see any note to this effect in the original plans. The building is not "fabricated" this is the term you would use to describe specific custom components (typically metal or architectural) that for one reason or another, cannot be fully detailed in the plans.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Has anyone mentioned the fact that a crane collapse on site in 1980 during construction may have doomed the foundation from the beginning?

Link

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (tmwaits1)

Quote (GPR_Tech (Civil/Environmental) 7 Jul 21 16:55 Quote (tmwaits1 (Structural)7 Jul 21 15:42) What I think we are missing is, we do not have a copy of the "SHOP Drawings" and those are what would have been used by the contractor to fabricate the building. We only have a mixed up copy of the Design Drawings. )

The reinforcement we are talking about should be fully detailed in the plans. For this reason, shop drawings would not be required unless this submittal to the EOR is specifically noted as required in the general notes. I don't see any note to this effect in the original plans. The building is not "fabricated" this is the term you would use to describe specific custom components (typically metal or architectural) that for one reason or another, cannot be fully detailed in the plans.
Maybe it's different where you are but anyplace I've been detailed shop drawings for the reinforcing as well as other portions of the project are required and reviewed by the appropriate engineers before a project proceeds. However, other than updating the engineering drawings to an "as built" version, shop drawings are not normally archived for the project.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (1503-44 (Petroleum)7 Jul 21 17:26)

"Is there some other transcript, not Geezer's, that you refer to?
Yes, it is the YouTube auto-caption (for what it is worth).

Quote (SFCharlie (Computer)(OP)7 Jul 21 03:21)

If the video is captioned(it is), YouTube should allow you to turn a transcript on(3 dots under the right edge of the video, "open transcript". you can then copy and paste the transcript into google translate
As I said at the end of my post

Quote (SFCharlie (Computer)(OP)7 Jul 21 03:21)

Ah! I love google translate, it seems particularly bad at Spanish (specially weird since google is in silicon valley, which is full of fluent Spanish speakers).
(maybe YouTube auto-caption is as bad at Spanish as google translate?)

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (tmwaits1 (Structural)7 Jul 21 17:24)


Maybe I should have used a better term than "SHOP Drawings" it should have been Placing Drawings
[The Detail Drawings for Reinforcing Bars in Site-Cast Reinforced Concrete Construction]
I know these types of drawings are not always required by contract but they are many time used in this type of construction, if for nothing more than the supplier of the rebar to be able to deliver the correct material for the job.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Apparently Geezer and myself heard and saw the same words on the video and arrived at the exact same translation, so let's vote Google's mash up out. There's no ice cream under the rubble. The other... maybe.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Maybe it's different where you are but anyplace I've been detailed shop drawings for the reinforcing as well as other portions of the project are required and reviewed by the appropriate engineers before a project proceeds. However, other than updating the engineering drawings to an "as built" version, shop drawings are not normally archived for the project.)


As we go forward, it will be critical to look at ways to improve the design, construction, maintenance, and rehab process to try and prevent similar tragedies from happening in the future. This is where my interest in this lies as I do structural design projects (bridges and buildings) in South Florida where the process is obviously less than ideal. It may be that "where you come from" is doing it better and we should be emulating it so I appreciate your perspective on how things are done elsewhere.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2

Quote (GPR_Tech (Civil/Environmental)7 Jul 21 17:21
OK why two different length top bars .30 L1/L2 & .25 L1/L2.)

Different lengths just to save money.
The practice is (was) to provide reinforcing where moment stresses require, and extend that reinforcing beyond the point of requirement to develop (anchor) the steel. The negative moment rises sharply near the supports, if continuity is present, and the need for steel reinforcing rises also.
Then there is the issue of not beginning or ending ALL the reinforcing at one point and "feathering" out the amount to ease the loads resisted by reinforcing as they may transfer into the concrete.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (1503-44 (Petroleum)7 Jul 21 18:52)

let's vote Google's mash up out.
Yes! Thank you both! I'm sorry for the confusion that I and Google introduced. Perdóname

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (bones206 (Civil/Environmental)7 Jul 21 16:27
What I see in this photo is that one of the top bars was installed just outside the column cage.)

This is part and parcel to the note from the drawings that 25% of the column strip reinforcing is to be centered over the column. That requirement could be interpreted as 25% PASSING OVER the column or, conversely, as a symmetrical and balanced placement located on the center of the column - even if the strip of reinforcing were 20 feet wide.

A comment if I may about maximum reinforcing to prevent a brittle and sudden failure. While that may be the intent, the 'balance' can change if the concrete deteriorates and the point of over-reinforcing changes. If the concrete cannot do its part, the ductility is lost. On the other hand, if the reinforcing corrodes at a similar rate, the ductility may remain. I see that part as a bit of a chore to program and control.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (tmwaits1)

The reinforcement we are talking about should be fully detailed in the plans. For this reason, shop drawings would not be required unless this submittal to the EOR is specifically noted as required in the general notes. I don't see any note to this effect in the original plans. The building is not "fabricated" this is the term you would use to describe specific custom components (typically metal or architectural) that for one reason or another, cannot be fully detailed in the plans.

I get shop drawings for rebar for just about every new construction project I work on. Houston, TX, for what its worth. I would not anticipate this to differ much in the 70s or 80s.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (SFCharlie (Computer) (OP) 7 Jul 21 15:07 Quote (IEGeezer (Industrial)7 Jul 21 06:30) ...may find the video more interesting with a better translation. Muchas muchas gracias alma de piel (soul of skin) seems to be a brand of ice cream or a dance studio. Is this an Idiom? )


There's www.almadepiel.com, but otherwise I am not aware of it as an idiom.

Machine captioning is still primitive. As for translation, the one I had trouble with was "muro de corte", which was translated as "shear wall." That's too technical a term for machine translation. As a general rule, technical terms turn into something interesting. I came up with "plane of cut" based on context, as in: this is where the two halves of the buildings separated.

What YouTube autocaptions did was interpret "más de aquel" as "alma de piel." They are actually phonetically more similar than one would think by looking at the written word.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Typical Flat Slab reinforcing, I've used for decades...

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (RickyTickyTavi (Structural)
I would not anticipate this to differ much in the 70s or 80s.)

The requirement for shop drawings was the practice in our office in the 60s thru 2000s. Shop drawings can tell the engineer if his drawings were interpreted to meet his intent. If something does not fit the drawings can request further information or suggest a resolution. And shop drawings are the last opportunity for the engineer to review his design before there is a lot of material cut and labor expended. After that, changes or corrections become very costly.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

4
Reinforcing shop drawings sequence:
1. Engineer's design drawings - submitted to the building department for review and approval. (Maybe after a number of re-submittals) (City may send out project to private plan check firm)
2. General contractor selects rebar sub-contractor
3. Rebar sub-contractor prepares rebar details which includes layout drawings with mark numbers of every rebar. Separate drawing(s) for every bar - straight and bent with bill of materials coordinated with the layout drawing by mark number.
3A: Rebar sub-contractor has the set of rebar drawings checked in-house by the another person.
4. General contractor receives rebar shop drawings and layout sheets.
4A: General contractor also reviews rebar drawings and if ok, then submits them to the EOR.
5. EOR reviews shop drawings and layout sheets for final approval - possible a number of re-submittals.
6. After final approval, rebar is fabricated and delivered to the job site.
7. Rebar installers - using the shop drawings and layout sheets- install the rebar.
8. Inspection - maybe both the city and the EOR's inspector inspects the placement using the layout sheets as well as the EOR's design drawings before signing off on the pour.

Some place in this sequence, rebar mill certificates are submitted for approval. The inspector's are the last line of protection - and sometimes they get bad-mouthed - but I like good inspectors.
It is the rebar detailer that solves the placement problems - this shouldn't be done in the field.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (oldrun&er)

Reinforcing shop drawings sequence:...
Some place in this sequence, rebar mill certificates are submitted for approval.
It is the rebar detailer that solves the placement problems - this shouldn't be done in the field.
This is the sequence I'm familiar with, sometimes depending on the complexity of the job certain steps or jumped over, quite often the shop drawings are not reviewed in-house or not reviewed by the contractor or not by the EOR if it's a very simple project. Always at least 1 of those 3 levels review the drawings but quite often not all 3 of them. I've seen in many cases that the EOR is the only reviewer and in some cases where it's only SOG are strip footings it will be the contractor instead of the EOR. Normally from what I've seen these days the mail certificates are required more often than not also the mixed specifications from the concrete plant are required to be submitted in most cases. Of course, test cylinders are always taken in the field too.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Historical video footage of the crane collapse from 1980 during the South Tower construction:

https://www.youtube.com/watch?v=GJ9Jt1zPDMA

After taking note of:

- Where the Bluegreen Hotel is in these shots,
- The former parking lot where the crane was stationed,
- The location of the central core stairwell in the Polaroids

it appears the boom fell NE across the 2nd floor of SE corner of the tower and over onto the pool deck.

None of the concrete appears to have been poured yet for this area (other than the columns) so damage to the deck concrete all these years later would not be a factor. But how the boom parallels the fault line of the deck collapse is downright spooky and perhaps some of the forms or rebar was damaged - but not badly enough to warrant reinstallation?

Also if nothing else it is interesting to see the earliest footage thus far of how the rebar in this part of the building was installed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

The Miami-Dade Country fire authority, who it seems is officially responsibly for the rescue effort, has notified the families still waiting for word on their loved-ones, that the rescue effort has now been officially moved to a status of recovery:

Search of collapsed South Florida condo shifts from rescue to recovery

No one has been pulled out alive since the first hours after the 12-story building fell on June 24.


https://www.tampabay.com/news/florida/2021/07/07/s...

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Mark R (Mechanical)7 Jul 21 21:31
Quote (oldrun&er)
Reinforcing shop drawings sequence)

A great sequence and program.
My main complaint was the General Contractor simply stamped the submittal to date it and put it in the out box.
Very little help from the contractor at that stage.
So if the EOR gets a submittal stamped by the General Contractor it COULD be considered a request to build it that way. If that meets the intent, the EOR COULD stamp it and - - is it the Contractor's responsibility after that?
Points for consideration at the court proceedings, I guess.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

"There's www.almadepiel .com, but otherwise I am not aware of it as an idiom."
That www is an advertisement for a leather "piel" handbag design studio.
Its also the title od an old song by Tito Rodriguez.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (1503-44 (Petroleum) 7 Jul 21 21:57 ... It's also the title of an old song by Tito Rodriguez. )


I couldn't find Alma de Piel by Tito Rodriguez. Instead I found:

La piel de tu alma by Tito Rodriguez & Louie Ramirez (https://www.youtube.com/watch?v=PP4JRD25GVw)

While I was at it, do you remember:

Eydie Gormé and Trio Los Panchos - Piel Canela, Sabor A Mi, Granada (1964) LIVE (https://www.youtube.com/watch?v=kQeGLk4nGus)

And finally, do you remember the unforgettable coloratura soprano:

Xiomara Alfaro - Siboney (Hi-Fi Audio) De Ernesto Lecuona - 1957 ¡Ole Cuba! Film (https://www.youtube.com/watch?v=20wj3xS-6qg)

With a voice like that, maybe somebody was playing a recording of her and that may be a factor in the collapse. ;)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

3
I don't have any opinions on what the trigger was, but after reading through all of these threads a few bits of info haven't been mentioned yet.

In one of the permits dated 5/17/2021 they did some roof core testing and found a lot of "water affected roof materials."



You can see them graph this out on the map as well in the permit. Kind of makes you wonder if this is the "curious" thing he found.. although, it doesn't seem that curious to me. It is the one thing he actually documents about the concrete that seems like it'd fit though.



These are both from this permit - https://www.townofsurfsidefl.gov/docs/default-sour... It just seems odd that all they did was re-tar the roof before sticking a roof anchor right into the most effected spot on that map, only a month later. They mention ponding on the roof, and it looks like it's probably draining into the building right where that column is. Also, in a 3/3/1994 electrical inspection on the building they have a note that says "MIDDLE ROOF FACING SOUTH AND HIGHEST LEVEL OF ROOF NOT FINISHED" but there's no real info on when it was finished or what wasn't finished exactly.

At least two of the roof anchors were never installed, P21 and P23. Makes you wonder if they stopped for a reason, since they were already up there and mounted two of them in that spot.




You can see them missing on the right side of the highest spot of the building. I actually had to check the google satellite view too, but there were no pieces of that section of roof that fell.. so they must have not installed them.

In this article they also have an interesting photo near the very end - https://www.washingtonpost.com/nation/interactive/... (It's behind a paywall, but if you use an incognito window to load it it'll let you read it even if you've reached your max articles.)



It's taken from 409 and shows some broken up tile behind one of the planters that's probably over a column (the one that's between parking spots 24 and 31 and doesn't seem like it as part of the collapse), but mostly it makes it really clear the sort of view that Cassondra had when she called her husband. Seems like she would have seen the patio to 111 pretty easily, or anything falling from the roof.

Also, I also dug up an old photo of the garage on google street view and lightened it, and I think it's pretty clear that we would be able to see the column in the tiktok video if it was still standing.. and it confirms that it's exactly where those rectangular pieces are in that video. It's hard to see in this pic, but there's definitely a light spot where it is on the plans. If a car did hit this column too, we wouldn't be able to see it's license plates on the other side of the standing column. Perhaps it's obvious that it's missing, but I was a bit curious if the old plans even matched the basement column layout.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

This has a lot of good historical information on the three condo towers - https://www.miamiherald.com/news/local/community/m...

According to property records, the lady that sued them in 2001 and 2015 for water damage owned 112.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

jbourne - could anchors 21 and 23 have been cancelled, due to that portion of the building being cantilevered in a sense? It seems like they completed the roof tar without the anchors, suggesting they had decided against doing them.

Alternatively, the plan appears to show a north-south wall in the middle of the machine room roof. Is it possible that the contractor read the plan, and assumed 21 and 23 were not located on the uppermost roof?

Also, note that eastern edge of the 12th floor roof, over x10, is very wet. That area butts up against the penthouse wall. That is also directly over where the collapse appears to have started.

Hypothetical question for those with a physics background:

First, is it correct to say that a free-fall from the highest level, absent significant air resistance, would proceed as 32 ft/sec after 1 sec, 64 ft/sec after 2s, and 96 ft/sec after 3s? And the cumulative distance would be 16, 48, and 128 feet after each second, meaning that the FASTEST the building could collapse would be roughly 3 seconds?

Second, if the video was of sufficient resolution, and the speed of a falling object in the video could be estimated... couldn't that also tell us when the free fall started?

For example, if the video starts with a particular unit falling at 64 ft/sec, then the collapse could have started no later than 2 seconds earlier?

Just wondering if more details of the second or two before the video starts could be calculated based on the speeds of objects in the first few frames - especially if we saw two different sections moving at different speeds.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Js5180 - the free-fall distance at any time “t” would be d=16.1t^2 and velocity would be v=32.2t.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (Js5180 (Computer)8 Jul 21 02:53)

is it correct to say that a free-fall from the highest level, absent significant air resistance, would proceed as 32 ft/sec after 1 sec, 64 ft/sec after 2s, and 96 ft/sec after 3s? And the cumulative distance would be 16, 48, and 128 feet after each second, meaning that the FASTEST the building could collapse would be roughly 3 seconds
I get 32 ft/sec after 1 sec, 64 ft/sec after 2s, and 96 ft/sec after 3s? And the cumulative distance would be 16, 64, and 144 feet after each second, meaning that the FASTEST the building could collapse would be roughly 3 seconds
I don't think this changes your argument in any way
I'm sorry, but the video is too dark and fuzzy for me to measure all this. (I did a lot of work on the FIU bridge dash cam, which was much better quality. when you zoom in on a single frame, a lot of the definition your eye/brain "sees" from interpolating different frames, goes away.

how-to-calculate-time-and-distance-from-acceleration-and-velocity

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Thank you Charlie. The resolution seems like a major impediment for this to work.

JBourne,

I found an alternate diagram for the machine room roof which does not have the dividing wall:



Also, the last column showing in your 2015 streetview is the one on the northwest corner of parking spot 27. That is the same one standing in the tiktok, with the white top and yellow bottom. In the floor plan below, I've put a purple rectangle around it.

The next column, based on the perspective, should be in the red rectangle in the image below. It's not visible, but it doesn't appear to have ever been visible in a photograph. The one after that would be in the orange. It's also not visible.



However, the orange column was still standing after the collapse:

(photo: WSJ)

I'm inclined to think that at least some of the red column should still be visible in the tiktok video, while the orange one clearly is not. That makes me think that the red column went down completely. Arguably, there is debris leaning against the orange column in the tiktok video.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Js5180,

Ah yea, that's a better diagram. Still a bit odd that they're missing. Perhaps that's just where the stopped for the day.

And you might need to zoom in a bit on the street view pic I posted, but I do think there's a lighter spot that shows the red column between 27 and 28. It's pretty hard to see, and mostly just visible near the top of the pic. I couldn't find any better pics though, it seems like the garage lights are too dim during the day to see in that far.

It is sort of odd we can't clearly see that orange column #28 in the tiktok video too, if the deck was completely collapsed then. Seems like the slab must still be connected to the building, and that could be blocking the view to it.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quick question - how do you get historical street view images?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Js5180 - Yea.. I think it is a lot easier to see on the google image itself. When looking at a building on street view, there's a small clock right next to where it says street view, in the grey box in the upper left. You can actually see it in my pic, but that part's expanded there. Sometimes you have to click around a bit though on the street before you'll see that pic as an option though, I think I had to go to 2015 pics at the end of that road before I could get to that exact spot.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I think that I have read every serious post and either missed or no-one has posted information or asked about destructive tests that were recently made from typical cores taken from the pool deck, roof, balconies. Also there is no comment from anyone if there are construction records, shop drawing approvals, materials testing from the original construction. For liability purposes most firm and municipalities file this information.

APPER.42 Peng. Retired

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

La alma de piel is like the ‘soul of the place’ or ‘the bones’ one would take it like the soul of the building and deeper than the bones

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

apper.42,

The recent ones don't seem to be online anywhere, but there are some old concrete tests from 2002 buried in this old permit - https://www.townofsurfsidefl.gov/docs/default-sour...

Although, these seem to be from concrete they were pouring back in 2002 for repairs on balconies and the south wall by the pool. It does seem to say they tested it beforehand, but the results don't seem to be included. I know nothing about concrete, but with mortar you have to test the mortar first so you can make a close match or it won't adhere correctly. It seems like if they're aiming for a slump of 5 or 9, that's probably what they got back when they tested it?

Page 33:


Page 81:


That's all the info too btw, nothings on the bottom of those pages. There's also a curious note on page 15 of that permit about 204 having an uneven slab.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

That Eydie Gormé link has several classics. The Steve Allan Show. I was 7 or 8yrs, but I do remember that. Solamente Tu. Singer at my Colombia hotel bar liked that one. Dios mio. 03:24 Granada. Saludos desde Canarias.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

3
This video is interesting too.. a walk through including the garage that someone did of the building in 2020 - https://www.youtube.com/watch?v=w4rGWH7aDJc

They don't show the exact columns that are suspected to have failed, but they all look like they're in good shape. All of the columns that punched through are in it. She does seem to show some exposed rebar in the garage, but it's under the portion that didn't collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I saw at least one security camera in the garage from that video.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

New 2020 Garage video shows area under the pool deck/parking area that collapsed.
Start @ 4:40 and walk-through continues to the exit ramp.
https://youtu.be/w4rGWH7aDJc
@ 4:07 they view some ceiling crack repairs under the portion of the building that remained standing. (near Parking spots 55 & 66)
[Thanks - jbourne8 (Computer)8 Jul 21 10:00]
.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2
Jbourne.

The Columns highlighted Js1580 post are visible in the video @ 4:50 to 4:53.

The slab (garage ceiling) looks a mess of painted over, patched up ("repaired" cracks, and are those Stalactites on the underside?? Possibly underneath de-laminated paint, or what.

there's also standing water everywhere.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (JimmyP80 (Computer)8 Jul 21 11:45
...are those Stalactites on the underside?? Possibly underneath de-laminated paint, or what.)


They are likely unremoved epoxy injection ports and not stalactites.
.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

JimmyP80 - Sure.. but if someone told you that this building was being condemned during this video because it was going to collapse in the next year, wouldn't you still ask what would cause that? I live in Seattle, and I didn't see anything in there that I haven't seen in many apartment buildings here.. and worse. None of them suddenly collapsed though. A little standing water in garages is pretty normal really.. the cars bring it in when it rains. It was built to withstand hurricanes that can completely flood the building too.

It's sort of interesting that only about half of the garage ceiling has that problem too, most of it seems to be in perfect shape. Near the entrance it doesn't end where the building starts upstairs, but about halfway between the columns instead.


The column on the left in that pic is the one from the tiktok video, and the one on the right is the pillar that seems to be collapsed in the video.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04



Also notice the bottom right hand corner marked in picture that punched thru on other end of planter

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Thermopile (Aerospace)8 Jul 21 13:16)


.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I cannot imagine the slump for any sort of corrosion resistance... don't even use this for ICF walls...

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Thanks GPR_Tech, it all makes sense now!

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (sgw1009)

Video below shows good views of garage on walkthrough - 9 min in to 12+ min in:

https://www.youtube.com/watch?v=QbjRUvCGRXc

This is the Champlain Towers North walkthrough, and has been posted (not to mention translated) before.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (sgw1009 (Computer)8 Jul 21 13:52)


NOTE that is a video of the NORTH tower and not of the SOUTH tower. (South is the one that collapsed)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

As predicted, there is now political pushback to the proposal to inspect all older condos in Florida. In another month the whole event will be part of forgotten history.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (DavPC)

Historical video footage of the crane collapse from 1980 during the South Tower construction:

https://www.youtube.com/watch?v=GJ9Jt1zPDMA

Great find, DavPC! I wonder who had this video on hand all these years, perhaps a TV news archive?

Makes you wonder how the repair work was done, as you noted.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

9 inch slump? Really? Unbelievable! Seems that the cement company had a hard time even making it. Actual was only 8,5". Ran out of water on batch 9/9?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04



The screen shot from GPR_Tech's 2020 walk thru shows the beam that connects the perimeter of the building at column line L, and this beam tie for perimeter of the East side of the building exists starting with K column line thru M as well as 3 more column lines.

Seems like this strong tie between building perimeter and patio deck would tug even harder on the building once the patio end collapsed? Tug harder than if just flat slab in that area.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (9 inch slump? Really?)


and they added water on site?

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Column Line I does not have this beam tie to patio deck

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (1503-44 (Petroleum)8 Jul 21 15:43)

9 inch slump? Really? Unbelievable!
For us dummies, Could we have a very brief explanation of "slump" Is more inches sloppier?

Concrete Slump Test - Tutorial (for dummies)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

More slump is easier to place, since it flows easily to all corners of a slab. 9" is almost self-leveling stuff. But more water decreases compressive strength and increases shrinkage.

Jezzz! Didn't see the 'nother 3 gal.
According to USDA (PDF)
1 gal added per year. = -200 psi f'c
So thats f'c -500 to -600psi less.
So it must have been something slightly stronger than compact baby powder.
Is that the reason why the bars zipped out so clean?
Most look like a skinned squid.

The date is '02, so maybe only used for repair work or pressure injection?
Edit.[and its 3 gal added to the 9yd load, so not so bad as I thought.]

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I could be mistaken but the 3 gallons added is likely for the full truck (9 CY) so 1/3 Gal/CY. The USDA doc you reference is referring to strength loss due to a gallon of water added per yard.

We all cringe with water added on site, but I highly doubt that this particular 3 gallons added to repair concrete in 2002 has much of an impact on anything of significance.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Yes, you are probably correct. ... Hopefully so. Sorry I panicked just looking at that.

Are there any concrete tickets remaining from the 80's? Long shot...

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Thermopile)

Column Line I does not have this beam tie to patio deck

Those are not the correct plans for anything resembling as-built as far back as ‘81.

Surfside did not have electronic Building Dept Archives which has resulted in very confusing and out of order plan sets after scanning and uploading what has been found in storage for FOIA requests.

Several had asked about saving evidence from the office before the remaining portion was demo’d without understanding the interior lobby slab had also collapsed into the basement in that area.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

One thing that seems a bit strange in that video is the water pipe near the garage entrance:


Here's another shot of it when she pans to the left:


This is the same pipe that's broken in the tiktok video:


I always figured that it broke because it turned towards the pool at that spot, but it's clear that it doesn't. Instead this seems to point towards a failure near this circle before the video started:


I think this might indicate that the tiktok video and the ring video were taken at the exact same time. I always assumed the tiktok video was a few minutes earlier, but this does line up well with how the kitchen dividing wall is leaning in the ring video. Perhaps there were already multiple columns under the building that were collapsed when she started taking the video.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Thermopile:

A technicality, but I believe that the beam in the picture is actually column line M (M10-M11), but that doesn't change anything. Note that there is an 11" floor drop in the middle of that beam, making a step in the beam. To make matters worse, they plunked down a very large planter right at the step.

Also note the complex geometry on column M10. The SW quadrant floor is patio height (12'9"), the SE quadrant is pool deck height (11'10"), and the north half is lobby level (13'4"). I'm not saying that this is unacceptable, but it would cause some head scratching on framing and bar placement and there is insufficient detail on the drawings to define how it should be done. Given the ease with which the columns in the pool area punch sheared through, I don't have a great deal of confidence on the floor attachments in this complex area.

As you pointed out, the bottom of the lobby and patio level floors look good, but you can draw a line where the patio ends and the planters start. It would be expected to have a small amount of sag at the center of that beam and the floor step would insure that any leaks through the waterproofing would collect along that step line.

The floor drops, beams, and planters south of column line 10 and K-M form a very rigid box structure supported by the line 10 columns to the north. Note that the NW corner of this structure is K10 which corresponds to parking spot 78. If there was a pool deck failure between lines 10 and 11 (possibly at the slab step), this structure could put a huge moment on columns K10, L10, and M10 and may have inflicted the fatal damage. The columns held for a few minutes, finally gave way, and the rest was a foregone conclusion.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

[quote Santos81][/Those are not the correct plans for anything resembling as-built as far back as ‘81.]

Santos81, I agree Sheet 5 of the Structural Plans I posted above is from the Surfside archives and is a 1979-80 Vintage Design Drawing. I would think 'As-Built' Drawings are just mark-ups of the Design Drawings to reflect changes back in 1981, as plans were paper back then on job sites, and not digital.

I can't image a builder deleting or adding concrete columns or beams in his as built, without consulting the design engineer. However, what they have uncovered so far, says this builder/developer may have been making lots of changes without getting approval from the EOR. So who knows what as built would really look like on this project, and now most of the evidence is gone.

My only point was comparing design drawings to the video from 2020, you can clearly see the Beam between column 27 and 28, which is consistent with the 1979/80 design drawing I posted. Thus, in this case as built looks a lot like the design drewing.

Point of my post was the building is tied firmly to the planter deck area, so any deterioration of the planter area is not isolated structurally from the building, thus failure of deck causes progressive failure of building.

This looks like a terrible idea to not have isolation joint between building and elevated patio deck.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

So let's look at some numbers if we assume the Tik Tok column is collapsed.

Column at L/10 - the yellow painted column adjacent to the presumed failed column in the Tik Tok video - is a 16"x16" column with 8-#11 at the basement level. Rough numbers assuming 50% live load, it was carrying 640k. The 9 1/2" plaza slab frames into it with hooked #5 at 12". Assuming yielding of the slab (moment = 11.6 ft-k / ft) for the full tributary width of that column puts 240 ft-k of added moment to that column. Much of that moment would redistribute into the Lobby slab (only a 7" elevation difference). Column interaction diagram gives us a Phi Pn = 640 k with a phi Mn = 240 ft-k. While redistributing moment into the lobby slab will remove some moment, it will also increase axial load to the column from the lobby floor (maybe 15k). Another nearby point on the interaction diagram is 710 k, 220 ft-k. So this is close, but still under the limits of that column.

The collapsed column would get the building column close to failure but not necessarily exceed the column capacity immediately. This allows for the progression of failures to occur as provided by witnesses. I'm still resistant because a vehicle impact on a 12x16 reinforced column (beam connected)supporting 30,000 lbs of weight would not impart enough energy to really even be noticed by that column. To me, the failure is from something else.

Would love to see what the chloride content is in the top of that plaza slab, but even that is probably well localized to the leaks in the plaza membrane (there is a membrane right?)

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Thermopile)

Seems like this strong tie between building perimeter and patio deck would tug even harder on the building once the patio end collapsed? Tug harder than if just flat slab in that area.

Tug harder, or damage more of the column's rebar cage as it detaches, or hold onto the column for longer and act as a giant rigid & heavy lever applying torque. It seems guaranteed to have some sort of larger influence on the attached columns than the basic slab, especially in failure scenarios, none of it good for the capacity of the columns.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

MikeJ65 thanks for your correction of my Column line error, and especially for your further explanation of the asymmetric moments and shear loads on those columns.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I've read all parts of this thread with fascination. Not being structural or civil I would ask what may be a dumb question:

What was the design life of this building? If it was 30 years then a good job was done. If it was 100 years then maybe not so good.

What determines end-of-life, everyone out and its taken down?

Cheers


Politicians like to panic, they need activity. It is their substitute for achievement.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Can anyone comment on drawing S.5 of 14 showing:
[Pool side of the BLD that collapsed]
UPDATE-
1.) Basement Column line 9.1 (offset 8") from the grade level of building Column line 10
. (answer for offset of 8" is because it is not the center line of the column but the outside edge of the column)

2.) Change in slab Elevation along/near column 9.1
. (this may or may not have been a contributing cause of the collapse)

3.) No Beam (BM-A) under at column I / 10
. (answer is because change in slab elevation is within the column)

Sections taken from S.5 (Pg. 31 of 336) https://www.townofsurfsidefl.gov/docs/default-sour...
.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

GPR, 1) There is not really an offset. 9.1 is column CL, 10 is outside line of building. 2) Pool deck is 18" below lobby level. 3)BM A is required at column lines K-M because there is a slab step mid slap between 10 and 11. Column line I steps down the full 18" on line 10, so beams would not be required.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Jbourne8,

My old eyes see what seems to be a slight pitch downward in that large, white pipe. Even if there is no slope, it looks more like a PVC drainpipe of some sort rather than a pressurized water line.

The south-pointing spray direction of the water in the TikTok video says to me it is one of those red fire sprinkler water lines that broke, perhaps the one on the right side above the ramp in your first attached image. If so, I am still perplexed why the fire alarm didn't sound, which could have saved many more lives. Instead we had a few residents (and even the security guard) wondering what all the loud noises were and everyone else remained unaware anything was happening.

On a slighltly related note, that garage video once again confirms what was reported in 2018 - the exposed sections of the concrete deck lacked sufficient waterproofing and were moist enough to cause the paint to peel off.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

4
I'm not sure if it was mentioned yet but I wanted to add this because I just found it. It's their minutes report from their October 2020 meeting. It looks like they did exploratory demolitions and there's some photos in there.
This appears to be where the "curious results" is from.


Quote:

This initial work yielded
some curious results as it pertained to the structural slab’s depth, and MC requested that additional core work be
performed by CPR to confirm/clear-up said results. CPR performed 6 separate cores at the direction of MC. The
results of exploratory demolition and the additional core work are summarized in the attached “CTS Test Probe
Notes” file.
Direct link:
https://s3.documentcloud.org/documents/20985354/20...

Source:
https://www.npr.org/sections/live-updates-miami-ar...


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Regarding the broken water line in the intermediate collapse video into the garage… wouldn’t there be much more flow from this line if it were a broken main or fire suppression line?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Penagwin (Computer)8 Jul 21 20:41)


Did they really have to cut right through the Rebar?
and then how did they, after coring through the Rebar restored each exploratory (and core) location back to its original
condition?
Pg 39 of 83 "At completion of the investigative work CPR restored each exploratory (and core) location back to its original
condition"
https://s3.documentcloud.org/documents/20985354/20...
.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Thermopile )

Santos81, I agree Sheet 5 of the Structural Plans I posted above is from the Surfside archives and is a 1979-80 Vintage Design Drawing. I would think 'As-Built' Drawings are just mark-ups of the Design Drawings to reflect changes back in 1981, as plans were paper back then on job sites, and not digital.

I can't image a builder deleting or adding concrete columns or beams in his as built, without consulting the design engineer. However, what they have uncovered so far, says this builder/developer may have been making lots of changes without getting approval from the EOR. So who knows what as built would really look like on this project, and now most of the evidence is gone.

My only point was comparing design drawings to the video from 2020, you can clearly see the Beam between column 27 and 28, which is consistent with the 1979/80 design drawing I posted. Thus, in this case as built looks a lot like the design drewing.

Point of my post was the building is tied firmly to the planter deck area, so any deterioration of the planter area is not isolated structurally from the building, thus failure of deck causes progressive failure of building.

This looks like a terrible idea to not have isolation joint between building and elevated patio deck.

It would have been helpful if a complete permit set was maintained. Perhaps then, if those had existed, this may never have happened. After the first penthouse revision and second upper penthouse addition, none of the work from that point required as-built plans for the full building.

Those core samples should have been an immediate cause for shoring up the slab. There’s way too much structural steel for it not to be obvious something was off.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (GPR_Tech)

Did they really have to cut right through the Rebar?

Take a very close look at Core A.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Spartan5)

Regarding the broken water line in the intermediate collapse video into the garage… wouldn’t there be much more flow from this line if it were a broken main or fire suppression line?

If the outdoor slab had dropped from I to M, or the elevator shear wall to N, there would be around 2 sprinkler pipes per bay broken, 6 to 10 pipes broken. As I understand sprinkler systems (not an expert), they are usually designed for something like 9 heads simultaneously at full pressure (i.e. the fire origin and surrounding 8 heads). Each head has a fairly small jet, so the flow looks plausible to me with many broken pipes.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Hook Bar

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Was structural slab two layered pours?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Santos81 (Specifier/Regulator)8 Jul 21 21:4)


It looks like it could be a Rebar chair to hold up the upper rebar layer. There are many different types.
.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Stirrup that was under and not around rebar?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Nice doc from 2020. I think this quote in the minutes for the October meeting might be the curious thing he found - "The front drive area concrete thickness is not matching up to the as build drawings the Association has on file. It is suspected that when the building was built, they sloped the top side of the structural slab giving us various thickness on the slab."

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

The J-Hook now is looking like they drilled directly over a beam below. Depending on which version of S5 drawing you look at, that beam is either between L and M under the planters, or that beam is 1/2 way between planters and wall

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (GPR_Tech)

It looks like it could be a Rebar chair to hold up the upper rebar layer.

Possibly. Thing is, the planters had a different configuration than what was shown on the original sets.

That last 1’11” slab drop from the 1st floor terraces seems to have been changed, with a beam or substantial drop cap added right where they took that core.

It’s still a bit early, but a few dynamic alternate load path models with those core points included reveals a very familiar footprint.

It still requires a trigger event and someone knows what that is. If the time of the TikTok video is correct, it narrows the individuals in the garage after it was taken down to two, and they’ve already left the country.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Granted it's just a fuzzy photo taken at an oblique angle, but this beam looked noticeably deflected to my eye as soon as I saw it. I added the red reference line.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

This site has a lot more building permit info for individual units, and the docs from the gov site, but nothing new or interesting that I can see - https://surfside.one/public-records-search/

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (bones206)

Granted it's just a fuzzy photo taken at an oblique angle, but this beam looked noticeably deflected to my eye as soon as I saw it. I added the red reference line.
A couple of other photos have been posted finding showing something like aquatic fumes all in the United mine project of the 6 we got hit making good Mike thanks what people thought was distortion but it's hard to tell from photos because in many cases the lens (especially wide-angle ones) have a tendency to distort images, especially straight lines. Besides any significant deflection of concrete would cause significant cracking of the beam.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8)

nothing new or interesting that I can see -

Since a few members here have been submitting FOIA requests, it wouldn’t be a bad idea to include historical land surveys, archaeological surveys, historical deeds, and plat maps back as far as 1824 or so. Quite fascinating.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

If you are concerned about lens distortion causing the curve in the beam, place similar red lines on those horizontal pipes. If it's lens distortion, they will all have curvature, too. In appropriate amounts (worse farther from the center of the photo).


spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Distortion can be tricky to really verify on a photo but a lot of times you won't have the same problems vertically that you have horizontally, and you'll see more problems towards the outside edges of the frame. If you go to a part of the video where the beam is closer to the center of the frame it looks a lot more straight to me:

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

To put an end the whole OSHA, mechanical anchorage points to rest forever. I would never tie off on a roof point unless I could visually inspect every point, including the assembly that kept the rope from contacting any point of the rope. Fly an outrigger swing stage, with independent counter weighted points on the parapet I' am good to go.

I understand that steel construction with curtain walls do incorporated these things structurally, but structure of that class typically have crane to facilitate routine maintence, and are professionally maintained.

In this type of building, a single tie off as stated on the drawings is simply stupid, simply because there is no possible way it can support the swing stage necessary to periodically repaint/ repair the structure, and especially because we are no simply stupid enough to trust an expansion bolt.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (GPR_Tech Did they really have to cut right through the Rebar?
and then how did they, after coring through the Rebar restored each exploratory (and core) location back to its original
condition? )


I wish purchase of rebar eaters (rebar cutting drill bits), or anything that can cut rebar, required a signed permission slip signed by an engineer.

The only way I can think of repairing that involves making a bigger hole or cutting deep grooves to epoxy bar in.

Looking at the drawings I’m bothered by them calling the rebar “wire mesh”. I feel it would be more appropriate to call it structural steel.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Thermopile - That seems unlikely, since it doesn't cover the jeep at all. Also, I find it hard to believe that the pool water is traveling that far.. and fresh water won't damage a jeep. There also seems to be another one on the other end of the garage, but it's mounted at an angle. Maybe an extra light they can turn on for car work or something?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I figured the reason the Jeep was not pulled in all the way into parking spot was because of water damage, and that sure looks like the polycarbonate panels I used on my deck cover

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

You can see peeled paint all the way up to the panel too

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Fresh water may not damage a jeep. Is it still fresh water after it has percolated through that concrete-like substance overhead?


spsalso

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Yea, it's possible. The building may have even installed them, so the pipes wouldn't drip on people in the walkway. They had a lot of strict rules there it seems about what you could do with the main common areas.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

The video at the bottom (not the top) of this article is interesting too.. one of the residents documented that the pipes were leaking in the garage in 2018 - https://nypost.com/2021/06/30/gripping-recording-c...

Seems like it was probably taken from parking spot 113 though, and not the collapsed portion. Perhaps they're the pipes for irrigation for the front planter beds?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Rain water leaking through a concrete slab can without doubt damage the paintwork of a Jeep, or any other vehicle.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Lizard7709)

Looking at the drawings I’m bothered by them calling the rebar “wire mesh”. I feel it would be more appropriate to call it structural steel.
I think what they are talking about is actually WWF not rebar. It's mentioned in reference to the topping slab which is only 2½" which is to thin to put a tide rebar mat in. I don't mention what the reinforcing is in the structural slab.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Yea that rusty rebar looks nasty.... And I love the duct butter fix on the cracked pvc pipe

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (penagwin 8 Jul 21 20:41)

I'm not sure if it was mentioned yet but I wanted to add this because I just found it. It's their minutes report from their October 2020 meeting. It looks like they did exploratory demolitions and there's some photos in there.

Just reading through the presentation starting on page 55 of the Oct 2020 meeting minutes will give you a good sense of what condition the overall building and systems were in that time. It appears to be more detailed than the field reports we've been reading.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

If I was assigned to evaluate the safety of a building over 40 years old in a marine environment and with known problems in the deck waterproofing with at least 10-12 psf of superimposed load due to added overlay of pavers and a waterproofing layer, deteriorating balconies and a leaky roof, my priority would be to test the strength of the existing concrete in these locations. To accomplish this I would have concrete cores taken from the pool deck, roof slab and balconies. For the pool deck probably two groups of 6 cylinders each at the very minimum. Possibly more to be added depending on results. The roof would probably require another 3 at the very minimum in the wettest areas and another 6 from the worst looking and most poorly drained balconies. More to be taken later if deemed required.

The cores should be taken, visually inspected, prepped and tested in accordance with ACI 214.4R10 (Reapproved 2016). Results would be interpreted and adjusted if necessary for L/d ratios and variations in samples. Besides ACI 214 there are several publications and even Utube videos on coring, inspecting for aggregate, voids variations in diameter of each core, testing and interpretation. These strength tests along with a visual inspection sounding and other tests should give a much better of the structural condition than used in the 2002 repairs and the 2018 report by Morabito. Other inspection should probably include masonry parapet walls and any masonry shear walls and a quick check of the building loading and capacity if required.

If results found were as bad as I suspect then immediate shoring of parts of the structure would be appropriate until structural and other repairs or evacuating the building could be completed. Hopefully investigators will find enough in tact concrete from the critical locations to complete some strength tests.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (apper.42)

Hopefully investigators will find enough in tact concrete from the critical locations to complete some strength tests.

There's also evidence from CDI. Mark Loizeaux has 50 years experience of old concrete columns. Mark and his driller (presumably also a world class expert on what 40 year old concrete is like) both commented that it seemed very "soft" in places.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Has anyone figured out the mystery of the drop caps shown on the original plans? The video seems to confirm that drop caps were not provided. The plans are frustratingly silent on what those dashed line outlines represent, but I don't know what else they would be besides drop caps. Seems like a huge potential gaff in the design and/or construction.

And I still see the beam deflection, sorry. The stains on the left third of the beam do sort of suggest some nominal level of flexural/shear cracking as well. It may be nothing, but it's another data point in the area of concern.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

That deflection is towards the center of the photo.

Of two general types, that would be “pin cushion” distortion, rather than “barrel” distortion.

A showing that barrel distortion is inconsistent with the camera would prove the point. And I’m pretty sure a phone camera distorts away from the center, in the barrel shape.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Speaking of that beam, is it just me, or does it look like natural concrete when the rest of the columns/ceiling are painted white. Is it possible that this was an older repair?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (bones206)

Has anyone figured out the mystery of the drop caps shown on the original plans? The video seems to confirm that drop caps were not provided. The plans are frustratingly silent on what those dashed line outlines represent, but I don't know what else they would be besides drop caps. Seems like a huge potential gaff in the design and/or construction.

I would have to assume the dashed lines are designating the column strips. Bars specified over columns must lie within the column strip. But I havent seen any explicit definition of that on the plans.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Murph 9000)

There's also evidence from CDI. Mark Loizeaux has 50 years experience of old concrete columns. Mark and his driller (presumably also a world class expert on what 40 year old concrete is like) both commented that it seemed very "soft" in places.

Upwards of 50% loss in strength. Moribito had additional cores taken as well earlier this year for lab testing. It obviously was severe enough to hault all non-roof concrete restoration due to concerns with placing equipment on the plaza slab.

Alyn submitted his preliminary recommendations based on evidence collected so far. I’m not sure if it’s been added to the Public documents. Strong emphasis on new geotechnical surveys to compare with original geo core samples and concrete deterioration from tidal saltwater intrusion in below grade areas.

Concrete core samples ONLY after scanning to avoid compromising structural reinforcement.

Where CTS was constructed is a rather unusual location geologically, having been a natural tidal pool that was later enlarged before being filled to construct CTS.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

dold - the lines representing column strip extents is pretty obvious in hindsight, thanks for clearing that up.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

This pic comes from the report Pengawin linked above. It’s the test probe area in front of the 111 planter…

Is it just me or does there appear to be some sagging near the edge? Is that normal?



“NOOK-yoo-ler. It’s pronounced NOOK-yoo-ler.”

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Mark R I think what they are talking about is actually WWF not rebar. It's mentioned in reference to the topping slab which is only 2½" which is to thin to put a tide rebar mat in. I don't mention what the reinforcing is in the structural slab.)


You are correct. I’ve been reading too much way too late at night. I don’t like that they drilled through the bar. From my understanding, the plans show parts of the pool deck that have #4 and parts with #5 at the planters and column areas.

Reading the notes on the repair drawing they have a section that shows they are supposed to take steps to prevent from drilling through bar like that in the “core drilling” notes. I’m not seeing this note in the 2020 document, but since it’s a memo it might not be displaying all the pages.




Reading what Murph said above about the concrete having a reduced strength, I feel that may explain the sudden nature of the failure. Although it’s too early to know if that was the cause of the failure. I am genuinely curious about the foundation and what there is to learn about it’s condition.


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (You can see peeled paint all the way up to the panel too)


Don't read too much into this... because of the alkalai concrete, some oil base coatings don't fare well with concrete... I also see this in painting HDG material sometimes... there is a saponification going on sometimes.

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

A new report...

https://www.cnn.com/videos/us/2021/07/08/surfside-...

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Odd, that 2020 budget report doesn't seem to be in any of their public docs on either site. Is there a link to it somewhere?

There's also one thing I've been a bit curious about, and I haven't found a good explanation for it. I'm not a structural engineer at all, but I always assumed that the columns in the tiktok video were what initiated the collapse and not the columns that are circled in blue here:


I think that we might have misunderstood some crucial bits of those videos at the start of the thread.. which is pretty understandable because they're hard to interpret cleanly. The blue column (78 + 80) theory seems to mostly hinge on the surveillance camera footage from next door. But if you assume those top center lights that are on are from the 9th floor and that it hasn't fallen much when it starts, the angle they are at hints that they are actually level with each other in the first frame. A few milliseconds later the end under column 27 starts to drop much faster than the rest of the building. This is easiest to illustrate with a bunch of parallel lines, but only the still standing structure can really be trusted that it's level. Because of how far away the camera is, you can sort of use what you know about point perspective drawing and the top floors to see what level would be there.

All of these lines are parallel with each other and only use the top floors of the still standing building for reference on the angle of the line:


What actually first got me thinking about this was the ring video from 711. In the video you can hear a noise that woke it, and then a large box gets flipped to the right, and the popcorn ceiling that's probably raining down starts to lean to the right too. A wall starts to lean in the kitchen too, but I'm not sure how to interpret that part really. This pic is taken right after the second snap in the video, and it seems like the room is already leaning significantly to the right at this point if the ceiling is falling straight down. Something like this:


This angle also matches up very closely with the angle in the surveillance camera in the second frame I posted. Right after that the entire table starts to slide to the right within the room, and then the camera slides slightly to the right and mostly to the back of the room (south) in the very last second. I think at that point we're actually watching the building collapse from the inside and it cuts off around when the power cuts off. Video will have a slight delay when they're uploading externally, but it was probably around 100-500ms before it lost power (most of the US is reachable in around 120ms or so). I know some people think the video starts at the second boom, but based on statements from survivors that was actually a few minutes before this video starts and I don't think it ever picked it up. Or if it did, it's most likely in another video clip.. these things tend to end the clip within 5-30 seconds or so of the movement/sound ending.

With the view we saw of the inside garage too, I think this might be what's going on with the rubble in the tiktok video:


The object on the ground definitely seems to the be the only thing painted white, and the planter seems to have a bit of green on it. If you create a parallel line using most of the vertical lines in the pic (red line) it also looks like column is leaning a bit to the right towards the top of it, and the top looks broken off.

But my question is this.. is this possible? And could this one column failing have caused a collapse of the entire rest of the building? It seems like it could have caused serious damage to column 27 because of how that horizontal beam on the ceiling was tying them together. And with how skinny all of the columns are, and how soft they say the concrete is, it seems like that alone could have caused a complete collapse of the building. Just seems to make more sense than column 27 failing and the ones in blue as well, with the column between them seeming to collapse after the building starts to fall (because of how slowly that section falls compared to the rest of the floor). But perhaps I'm missing something?

Of course, this still doesn't explain why the column failed in the first place.

Videos I mention here so you don't have to go dig them up again:
Surveillance video of collapse from next door: https://www.youtube.com/watch?v=KR29pLccutY
Ring video: https://twitter.com/_rosiesantana/status/140797089...
Tiktok video: https://www.tiktok.com/@adrianitacastillero/video/...
2020 view of the inside of the garage: https://www.youtube.com/watch?v=w4rGWH7aDJc

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2
Maybe its just me, but I dont see any hint in any of the videos that show a top to bottom failure progression. No pancake from roof to basement. I only see a more or less monolithic drop, the kind precipitated by loss of lower support. The upper levels visible in the videos all dropped at the same rate, as a unit. Any pancaking occurred at the bottom. The lower column(s) failed first, perhaps from the pool deck pulling them out, or maybe from compressive overload of lower columns from excessive roof loads, but do not really believe that is likely, unless you consider the extra roof load became enough cause to buckle lower columns, but only after they lost the lateral stability that was being provided by the ties to the deck structure. I just can't see any top to bottom progression.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

jbourne8 (Computer), excellent work on reinterpreting the videos. The garage is still a mess but i like your idea of the horizontal component. That would have been cast as one piece with the floor slab above it so I suspect that the area to the right is the underside of the pool deck sloping down to the garage floor and impeding further view into the parkade.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

1503-44 (Petroleum), I agree, the failure was from the bottom up or an inverse pancake.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

1503-44 - I agree with that too, I think it started from the basement. The numbers I reference are the parking space numbers, not apt numbers btw.

Sym P. le - Thanks! Yea, another interesting thing that 2020 garage tour showed us is how well lit the garage was, so it seems like the dark end must be collapsed back there.. or at least the lights are all off which makes it impossible to see. Only the lights under the building seem to be on.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

OK. With all the banter about drilling anchors for window washing and falling balconies, I thought others might be seeing that differently. Not to say that the loads from bobcats and roof materials didn't have an effect at lower levels. It all adds into the total. Just that I couldn't envision the roof or upper balconies collapsing first into those below.

And I do think the loss of just one column could certainly do in that whole side of the building, if the design was anything like I've done previously. I haven't done much commercial and residence work, only the TX A&M football stadium and gymnasium actually, but I wouldn't expect those types of structures to be more conservatively designed than chemical plants and refinery buildings and they would definitely not withstand the loss of any one column and survive in any recognizable form, so yes, losing one column would most certainly be enough to collapse the adjacent ones, then 2 more ..and so on.

Pardon me if all that has already been accepted by the majority. Its been a long story with more than a few forks, so I'm just trying to get a concensus of where the collective wisdom stands at the moment.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Can't seem to quote anyone , (is there supposed to be a quote button?) so I applogise if it looks like i'm ignoring peoples replies.. i'll reply when i work it out!


I have a question though.. Regarding the change in slab level at the main structure perimeter that was mentioned eariler by various posters, and is present in this simulation: https://www.youtube.com/watch?v=hynHiWE818

I can't see this in the garage inspection video? am I missing something?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote button is two places to the right of Smiley.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (JimmyP80 (Computer)9 Jul 21 11:03
I can't see this in the garage inspection video? am I missing something?)

It's hard to see the [Pool/Outside SLAB Elevation change] but look at the conduit go up at 45 degrees... it changes right there.
.

.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

As far as initiating from below, TeleMundo's interview with Adriana I think is rather convincing.
https://www.youtube.com/watch?v=I2F7Rv57L1k
They were probably the best eye witnesses to the moment and their focus was directed only to the lower level, rather than to any action above. Yes, they are at ground level, but even though, if something was breaking above, surely they would have noticed and focused on that. At 01:24, Adriana says she saw the "roof" collapsing, then the pipe breaking and water pouring down. She means the roof of the parking area, since she tells her father that she will stay there [to record] because "here something will happen". That area is where the pipe broke and water falls, so she is not talking about the building roof above. Then not seconds later a black cloud was coming and they ran for their lives.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

One thing that we know pretty well from eyewitnesses and video next door is that the slab between the pool and the building failed first. This is also corroborated by the site photos of the damage (see below). An excellent video of the probable collapse sequence is on youtube Link. The photo below shows classic punching shear failure of the slab at each column. A quick calculation of the punching shear demand vs capacity for this slab would confirm this apparent design flaw. If the original design calculated this wrong, it is likely that there are other aspects of the building structure where the design was also miscalculated. If there were design flaws throughout the building, it would help explain why this was not a more localized failure.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote:

Is it just me or does there appear to be some sagging near the edge? Is that normal?

That just looks like the sand layer to me.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Js5180)

That deflection is towards the center of the photo.

Of two general types, that would be “pin cushion” distortion, rather than “barrel” distortion.

A showing that barrel distortion is inconsistent with the camera would prove the point. And I’m pretty sure a phone camera distorts away from the center, in the barrel shape.


As someone else mentioned, the pipes in that video are straight, so it cannot be a lense distortion of the beam only. It’s either service load deflection or it was cast that way in deflected forms. If it was already a stressed, hard working beam with a lot of tributary dead load, then you consider possible rebar corrosion, soft concrete and perhaps even one of the main flexural bars was cored through by Morabito’s subcontractor… then I could see this beam failing and being the triggering event. I hope they can get surveillance video from those cameras in the garage.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04



Quote Button.
First Click: "Who?"; Add Title.

Quote (Add Title)

Second Click, (Click OK): Paste Quote.
Example:

Quote (JimmyP80)

(is there supposed to be a quote button?)

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

If only we knew someone who could do a quick punching shear calculation for these 12x16 columns supporting a 9 1/2" 2-way slab reinforced with #5 on top...

phi-Vc = 140 k, 1.4 x DL (9 1/2" + 7" concrete on 20 ft x 20ft area) = 115 k - so no. A failure somewhere else added load to these columns until they failed suddenly in shear. Testimony states that noises were heard above rooms 111 and 411 that woke them. Then 111 saw the plaza slab fail suddenly.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Teguci)

Testimony states that noises were heard above rooms 111 and 411 that woke them. Then 111 saw the plaza slab fail suddenly
I think you mean 611, not 411. And if I recall correctly, 611 just said they were woken by noises from outside (not above) and got up to close the balcony door.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Santos81 (Specifier/Regulator))

Several had asked about saving evidence from the office before the remaining portion was demo’d without understanding the interior lobby slab had also collapsed into the basement in that area.

This is the only reference in the entire thread to the lobby floor collapsing. Just curious what is the basis for that statement?

Unless the layout of the first floor had been repurposed since the original plans, the Security Office was immediately north of the elevator shaft, which survived (presumably).

The area to the right of the blue line had collapsed, but the area to the left of the blue line still stood. The Security Office should have still been there before the demolition.


Also, viewing the east side of the standing portion, the back of the Security Office would have been somewhere in the area of the red circle. This area still appears to be intact.


So hopefully the security footage was retrieved before the demolition.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (waross (Electrical)9 Jul 21 13:30

Quote Button.
First Click: "Who?"; Add Title.
Quote (Add Title))


How do you "add Title"?
[Hint I copy & past, but that wasn't clear at 1st.]
Is there an other way?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (bones206)

It’s either service load deflection or it was cast that way in deflected forms.

I was about to suggest the same thing. My guess is that the wood forms deflected a bit when the concrete beam was poured. If that beam were actually deflecting under service load, it would have cracks in the lower half.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (sgw1009)

This is the only reference in the entire thread to the lobby floor collapsing. Just curious what is the basis for that statement?

Unless the layout of the first floor had been repurposed since the original plans, the Security Office was immediately north of the elevator shaft, which survived (presumably).

The area to the right of the blue line had collapsed, but the area to the left of the blue line still stood. The Security Office should have still been there before the demolition.

This is the view from garage parking space 99 (under the plaza level drive) facing NW. The collapsed portions are from the lobby level (note the visible dumpster and trash chute) as well as a portion of the ground level driveway.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (GPR_Tech (Civil/Environmental)9 Jul 21 14:00)

Is there an other way?
Not that I know of...
Before I start to reply, while I'm still a the post I'm replying to, I copy the name and time stamp. Then I click on cartoon balloon, Paste, and OK.
Then I highlight just the time stamp in my blossoming reply, copy, and find (control f) and up-arrow in the find box (top of window) and copy what I want to quote, up-arrow again to get back to my reply and paste between the ][ marks. then place cursor after \quote] and reply.
(whoo, sounds like a lot of work to me...)

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

This clip is from the demolition. [Correction! of a different structure from a 2018]
Workers were apparently under the building while pulling down columns with a dozer winch. MIT grad and a city commissioner are shocked by the continuing negligence. Building Dept Admin won't comment because of the criminal investigation in progress.
In Spanish.
Skip to 00:51
https://www.youtube.com/watch?v=0EzlhBKW018

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (1503-44)

This clip is from the demolition. Workers were apparently under the building while pulling down columns with a dozer winch. MIT professor and commissioner are shocked by the continuing negligence. Building Dept Admin won't comment because of the criminal investigation in progress.
In Spanish.

That is not footage of CTS. It’s from the 2018 demolition work of 5775 Collins in Miami Beach that resulted in a premature collapse due to negligence.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

OK. Sorry and thanks for the correction.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8)

, and the popcorn ceiling that's probably raining down starts to lean to the right too

What is vertical in the ring video? Maybe not the room. The popcorn stuff will follow the gravity vector, which the real vertical, not the frame of reference of the camera. Note: This sort of camera probably has barrel distortion.

If you mount a wireless camera in a box and roll it down a hill, you won’t see much if the camera is mounted rigidly. Put popcorn ceiling in the box, different story.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

That new footage was pretty shocking anyway. Worker in the street wound up losing his leg and dying.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Santos81 (Specifier/Regulator)9 Jul 21 15:05)

This is the view from garage parking space 99 (under the plaza level drive) facing NW. The collapsed portions are from the lobby level (note the visible dumpster and trash chute) as well as a portion of the ground level driveway.

I don't believe this is correct. This would suggest that failure occurred to the west of the shear wall, although it's pretty widely accepted that the shear wall stopped the collapse. I think what you are looking at in the photo is columns E.1 and E.3 which were further north. In that photo, you can see the beam at E.1 which is a step down from the lobby to the outside.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (OK why two different length top bars .30 L1/L2 & .25 L1/L2... or WHAT IS THIS TELLING US?
(I just do not know what this detail would look like)
S.11 (Pg. 38 of 336))


I do this all the time... rebar is not terminated at the same location... minimises cracking. I use the same length bars and 'stagger' them.

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Torai)

What is vertical in the ring video? Maybe not the room. The popcorn stuff will follow the gravity vector, which the real vertical, not the frame of reference of the camera.

I think that was the point jbourne is making. He is implying that in that video the room is already leaning due to collapse of columns (possibly beam) that should have been visible in the tiktok video.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (CE3527)

I don't believe this is correct. This would suggest that failure occurred to the west of the shear wall, although it's pretty widely accepted that the shear wall stopped the collapse. I think what you are looking at in the photo is columns E.1 and E.3 which were further north. In that photo, you can see the beam at E.1 which is a step down from the lobby to the outside.

Fortunately it’s a video with numerous parking bay markers. I may be incorrect in the direction it’s facing, but it’s absolutely west of the shear wall.

https://youtu.be/MmleL6I2T5M

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I've been reviewing all the Spanish Language survivor account videos and happened upon the best explanation I have yet to see so far.
Great computer 3D models with critical columns circled. This collapse theory is from the bottom up and that there are no beams in the building above the first floor, which allowed an extra floor to be had for the same profile height as all the other buildings on the street. In Spanish. I'll do a translation later, or if Geezer is around ... his translation the other day was perfect, so maybe he could help out till I get back to it. Gotta run right now.
https://www.youtube.com/watch?v=jGUEwj-Pi54


RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2
One thing that is useful to estimate sequencing is that wherever we see the lines of rebar ripped from a slab soffit, we can infer that the adjacent slab collapsed first. That should be act as a sort of compass for the investigators to follow towards the initial failure point.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Jbourne,

I’ve been struggling to reconcile the 711 video for the reasons you’ve mentioned. The wall as appear to show that the left side of the room has descended. The dust shows the opposite. The table movement could be either - it could be pushed rightward up the floor by the out-of square wall at the left, or it could have slid rightward, downward.

However, the biggest problem I see with column 27 falling with no significant precursor on the roof is this:

If column 27 and those above it descended, we should be seeing the penthouse roof directly over it forming a V. That slab is the thinnest in the entire building.

The initial images indicate that the penthouse roof west of that column stack is 15 feet or so further down than the roof to the east, despite being supported by the exact same column.

While I agree that column 27 may be the main cause here, the differential collapse at the penthouse level needs additional explanation.

I’m thinking that what we’re seeing in the video is a cloud of dust, directly over the x11s, where the western end of the penthouse has collapsed prior to the main collapse - perhaps by only milliseconds, or possibly minutes, but earlier either way.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Click on the Quote Icon.

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Bill
--------------------
Ohm's law
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RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

BennyTheBeaver, I think by the time the ring video starts, the tiktok user is already running away from the site.. they say in one interview that it collapsed as they were walking to their pool to take another video. The person who posted the ring video says it was recorded at exactly 1:22am. I thought they were recorded at the exact same time, but that doesn't look possible anymore. That north end of the building also stayed standing and seems to be pulled down by the south end, so they may not have really seen the leaning from there.

Js5180, The wall on the left doesn't seem to be at enough of a tilt to push the desk to the right. Also, the camera is pretty clearly not being pushed by how it starts to slide to the right and then slides to the back of the room (south). I've also had a hard time figuring out why that large box would flip to the right and stay there if the building is leaning to the left. It seems like the first noise is probably column 27 collapsing with how that box jolts and flips.

Part of the building's roof has certainly already collapsed in that surveillance photo before it starts, but I can't make much sense of that really. That's probably why we don't see that clear V you're expecting at the roof line though. You can see it on the mid-floors around those lights that are on once you add in some level parallel lines for reference.

This is the closest before shot I've seen to their surveillance video, and it makes it clear how that roof line should have looked from that angle when it started - https://www.youtube.com/watch?v=8Pt7_ymjhpk The difference between where those white lines that go up end (at the 8th floor near the x11 rooms, with the two room lights that are on in the surveillance photo around the 8th or 9th floor) and the roof is strange since so much of it seems to be missing. But it still seems possible that they just collapsed a bit early because of the stress the missing column in the garage was putting on them.. the 711 room seems to almost twist internally as it starts to lean to the right, and the penthouse had a lot less columns supporting it. When that video starts column 27 is probably already collapsed. The person who escaped 611 also said that large cracks were starting to form, and this seems to be around when the tiktok video was shot and before the ring video started.

The way that everyone describes the incident it's not really clear how much of the pool deck has collapsed when they look at it, or if that slab failure line in the pic was actually collapsed before the building fell. The force it would have taken to pull the slab cleanly from the fence seems to hint that it didn't detach from that spot until the building fell. Cassondra in 412 was right next to it and didn't think it looked urgent enough to evacuate right away. It's possible that the pool deck collapse was much smaller then. Even from the lobby they should have been able to see over towards the edge of the x11 rooms and the entire x12 stack.. and a missing planter was probably obvious from there. There's a good chance that 111 ran from the building because of the odd state it was in too, with popcorn ceiling raining down, rather than just how the pool deck looked alone. I swear her daughter mentioned the ceiling raining in one of their interviews. It's odd that if the initial cause was punching sheer failure, that this first column that collapsed entirely in the tiktok video wasn't puncture sheered. It seems like that might be more of a symptom that the weight the missing column put on the rest of the pool deck. Could explain too why there's no slab material stuck to the tops of the columns if those were puncture sheered with great force as the building collapsed too. It all just looks so strange it's hard to make sense of.

I think if Mike Bell's reenactment was correct too, we'd see that entire part of the building collapse at about the same rate. Instead just the portion under the failed column in the tiktok video dropping at a much quicker pace and the rest dropping slower. It also seems to be the simplest steps that could have caused this. And sure.. popcorn ceiling doesn't always fall straight down, but it would have to be at about that angle for the table and camera to slide to the right. If you tilt your head as you watch the ring video to keep the popcorn ceiling falling straight down, it all seems to line up. The video is pretty horrifying when you view it as being during the collapse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I don’t think the YouTube shows the “before” from the camera’s perspective. Here are some I pulled from a video taken from a walking tour. The red lines are mine, the yellow arrow points to the camera that caught the collapse. The step down in the roof, I think, is far more profound than people imagine:






RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8)

Part of the building's roof has certainly already collapsed in that surveillance photo before it starts, but I can't make much sense of that really. That's probably why we don't see that clear V you're expecting at the roof line though. You can see it on the mid-floors around those lights that are on once you add in some level parallel lines for reference.

I believe the CCTV footage starts after the facade has dropped approximately 1 floor. The video from inside 711 suggests to me that the M line of columns (right hand wall in the 711 video, right hand side of x11 balconies in CCTV from South) dropped maybe about quarter to half a floor ahead of the L line.

The KLM section for the x11 stack basically falls together, but M leads a little to give the slant in the 711 video. The stairwell resists at the north of M, N initially resists at the south before failing well behind the KLM collapse and leaving O–P as the sole bay to briefly survive at the south. The I columns in the x10 stack also possibly lagged by about quarter to half a floor.

Check out Building Integrity's analysis of the roof collapse theories and sequence. I find it quite convincing. https://youtu.be/383SIaQDg0k

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Agree with jbourne8 and BennyTheBeaver. I want to time tag the video, and make a time plot of (1) the angle that the popcorn falls showing the right end of the room dropping, and (2) and popcorn angle at the left and right of the image (how trapezoidal - as the room tilts back and camera points more up in the gravity field, streaks from falling popcorn will spread more at the bottom).

When the box moves (1st 3sec) the camera does not move at all relative to what its sitting on, there is a change in the scene, maybe a little more on the right. Also the wall between the door and fridge and the area above the door seems to distort between the pre-box-move and post-box-move frame.

I would agree that if I was shrunk down sitting where the camera is at I would feel as I was falling to the right and backward.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (1503-44)

9 inch slump? Really? Unbelievable! Seems that the cement company had a hard time even making it. Actual was only 8,5". Ran out of water on batch 9/9?

9" is a relatively 'standard' slump value; 8.5" against a 9" spec is also completely normal. You can't efficiently pump low slump concrete.

Also, field measured slump values are never going to be exact; the specified target value is usually controlled in one of two ways; it's either a not-to-exceed limit, with lower slumps acceptable at the GC's discretion depending on how they plan to place the mix (ie pumped or not) OR it's a spec target with a tolerance (usually =/-1" IME, although ACI 117 allows +/- 1 1/2" tolerance for specified slump values above 4", because of the increased difficulty in accurately measuring higher slump values). If I reviewed a concrete spec from an engineer that called for 9" of slump, and when the mud showed up it tested at 8.5", neither scenario would be cause for a moment of second thought on my part. In fact, if 9" was a not-to-exceed limit in this case, I'd want concrete to show up between 8 and 8 1/2, so that I know I have a little buffer to the limit and I won't be worried about a load showing up that's over the line.

Posts above are inferring a great deal about the properties of the concrete without any hard data; looking at the slump value alone is meaningless unless we have access to the concrete spec and can determine what concrete strength, w/c ratio, plasticizer or other admixes, etc were specified, and we'd also have to be able to compare that to actual concrete tickets to determine what was delivered and placed.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Murph,

For the moment, Building Integrity’s roof collapse video has one serious flaw.

He states that the lights stay on in several of the units as they are falling because the electrical conduit is run vertically from the base of the building.

In fact, it runs horizontally from the 2, 3, 5, 7, 9, and 11 floors.

That doesn’t necessarily disprove the rest of his analysis, but a unit falling 15 feet with a horizontal electrical feed is not consistent with the lights staying on.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Santos81)

Fortunately it’s a video with numerous parking bay markers. I may be incorrect in the direction it’s facing, but it’s absolutely west of the shear wall.

https://youtu.be/MmleL6I2T5M

I believe the very first few frames of the video positively identify the location beyond any doubt. In the first frame of the video, there is a double column on the left of the frame towards the back. I believe this can only be columns A.1 and B.1 in row 2.1. That puts the drilling firefighters between columns D2 and D5, drilling east into roughly the E line. I can't see any other combination of columns in the NW quadrant of the basement that fits the framing plan so perfectly. That puts them west of the shear wall line, but in the north half of the structure, north of the shear wall and corridor. Without checking, I think it's roughly under the service entrance / loading dock.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (santos81)

Fortunately it’s a video with numerous parking bay markers. I may be incorrect in the direction it’s facing, but it’s absolutely west of the shear wall.

https://youtu.be/MmleL6I2T5M

At 0:09 I see 117 and 118 on the column for the parking slot markers. That would put this shot at the northernmost row of parking spaces (if the plans are correct) and the camera ends the shot looking east at the attempted rescue. So yes, if it hasn't moved the security office should have still been there. However, this shot from 2020:



shows there has been some reconfiguration. For example the nearest door is now much farther from the elevators so it's not clear if that new door in the pic above still went to a security office or if it was now in an entirely different location.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Murph 9000, Personally I stopped watching building integrity's videos when he suggested rolls of roofing paper may have caused the collapse heh. He seems to just be reading this thread and regurgitating it, instead of posting his own ideas.. he made that video right after it was discussed in here a lot. And he misses a lot really. The roofing paper was mostly just suggested in here because of the green in the tiktok video, but I think those are just planters on their sides too. But yea.. I do agree the roof is partially collapsed when the surveillance video starts, but that part I'm pretty sure he took directly from screenshots in an earlier thread here too.

If the roof was that collapsed I think the tiktok user would have caught it.. and if a substantial bit of roof was on the ground or was tumbling down the balcony area I don't think Cassondra in 412 would have stopped to call her husband. She also probably would have mentioned that instead of saying that just the pool deck collapsed.. she thought it was a sinkhole if I'm remembering right. I did consider the roof anchors for a bit, but it just doesn't seem to fit. I think the upper levels just collapsed a few seconds before the surveillance video starts, because column 27 has then collapsed and it's putting too much pressure on the rest of the building. The ring video probably starts around 10-11 seconds before the surveillance video starts, based on when they lost power and the tilt of that area. I figure the roof was collapsing during the start of the ring video.. perhaps that's what woke it up. By the time the ring video starts the tiktok users phone is probably no longer recording and they were walking back to their pool area.

And I'm pretty sure that column they're looking at in the basement is 118 btw, they're facing the collapse and trying to rescue someone from the bottom floor. I think they said she was a 14 year old they never reached. It's probably taken from spot 112. Pretty sure this was already discussed earlier in this thread too btw.

I've been watching the live feeds a good deal and I've been a bit surprised how little they've been investigating where things have fallen on the bottom of the rubble pile.. I sort of doubt they spent a lot of time getting the CCTV stuff out. It's probably very difficult to find someone willing to risk their life for CCTV footage, and it might not be straight forward to find.. a lot of time it's stored in a closet.

Perhaps this doesn't apply, but with tech.. usually the simplest answer is the right one. It seems like the simplest answer here is just that the column that's collapsed in the tiktok video (between spaces 27 and 28) caused the entire collapse within a few minutes. All of the rest might just symptoms based on how it happened to fall.. but it seems like it was going to collapse at that point no matter what. When CDI said that the concrete was soft too they were probably just talking about the foundation where they were drilling, which seems like it was never tested by MC.

Also, this is probably the most interesting thing I've seen on the live feed.. I think this is the column between spots 77 and 76. Interesting that it seems to have fallen in the same direction as the collapsed column in the tiktok video, which is right next to it. It seems odd that these columns could have fallen to the southwest if they fell with the pool deck and it collapsed straight down.


Perhaps Cassondra's description was right and the column collapsed by a sinkhole, pile issues, foundational, etc too. It just seems so bizarre that a column could topple over like that if it wasn't coming from below it.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

A column failing in buckling will fail in the axis of the longest (remaining) effective length, KL/r, unless it was acted upon by an outside lateral force, which would mean it failed in bending caused by that lateral force, not buckling. If the column's lateral restraint was removed (supposedly by the failure of the pool deck), and it failed in buckling, it would most likely fail towards the item that was providing that lateral restraint. Did they fail in the direction of the pool deck? Then it was pulled by the pool deck, there should be some evidence of stretched bars at the connection point, or if not, then it lost lateral restraint in that direction and buckled without help of lateral pulling by the deck, or some combination of both. If its a clean break, no evidence of bars being pulled out of the column (the column looks like a pencil point) then most likely an axial loaded buckle failure. IMO.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Murph 9000)

I believe the very first few frames of the video positively identify the location beyond any doubt. In the first frame of the video, there is a double column on the left of the frame towards the back. I believe this can only be columns A.1 and B.1 in row 2.1. That puts the drilling firefighters between columns D2 and D5, drilling east into roughly the E line. I can't see any other combination of columns in the NW quadrant of the basement that fits the framing plan so perfectly. That puts them west of the shear wall line, but in the north half of the structure, north of the shear wall and corridor. Without checking, I think it's roughly under the service entrance / loading dock.

In other words, working into the collapsed lobby.

The trash room and chute were in the same location as shown on this plan. The security room didn’t exist. The mail room was moved south and a closet added north (after deciding against a separate UPH elevator in that location).

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

The lady in 111 said that security was right on the other wall from her apartment in one of her interviews btw.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

This seems to be a fun paper that will be very very popular in Miami for the next few weeks ...

There are limitations to Ground Penetrating Radar in detection of rebar details in reinforced concrete structures !!!

An excerpt from the paper ....

It should be noted that GPR does not directly measure the diameter of a rebar, cable or conduit [10]. GPR when used with the larger diameter of rebar, can produce a stronger reflection of the radar wave. Due to signal wavelength, any object under 2″ (5 cm) in diameter is a “dot” with no visible size [10]. It should be noted that the reflection strength depends on several factors such as depth of the slab, area of slab and properties of concrete and steel. Thus, it is very difficult to obtain an accurate measurement of diameter of rebar in concrete.

https://www.sciencedirect.com/science/article/pii/....

MJCronin
Sr. Process Engineer

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Ultrasound has a shorter wavelength. Interestingly, this study was done in Florida.

https://journals.sagepub.com/doi/abs/10.3141/2251-...

Somebody will have to pay to find out if it was effective or not.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04


Quote (MJCronin (Mechanical))


This seems to be a fun paper that will be very very popular in Miami for the next few weeks ...

Although this particular paper is focused exclusively on GPR, I would guess that X-ray imaging and destructive testing will be NIST's tools of choice for investigating the as-built reinforcement situation at Champlain Towers South. But no doubt there will be a huge uptick in demand for both GPR and X-ray inspection services throughout the region. Perhaps everywhere.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

For the Spanish video, you can turn on autotranslate of the closed captions in the video settings (the gear icon). H/T reddit.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8 )

The lady in 111 said that security was right on the other wall from her apartment in one of her interviews btw.

That’s not what Ms. Nir meant by her statements, rather that her unit was closest to the front desk.

It’s not a guess as to where it was located. The CCTV monitor and Fire Control Panel are a dead giveaway.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (SFCharlie (Computer)(OP)9 Jul 21 21:58)

Attached: a Microsoft word file with 2 columns auto-caption Spanish and google translate conehead English
Someone Please correct it. Thanks.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (SFCharlie)

This is an excellent video, 300K views, 20K Likes
WHAT was the CAUSE of the MIAMI building COLLAPSE | Teacher explains moment of COLLAPSE and FALL
Worth your while to watch even without understanding the Spanish

Thanks for sharing. Dude has some chops. A few observations:
A. What a great model he has. How do you think that was generated? Time? Pretty neat.

B. I’m glad he added a caption of the word pandeo because I heard something completely different.

C. I thought he was using graham crackers to demonstrate punching. Then I thought he was going to build a whole physical model out of them.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Ah, the hard drive and server don't have to be located near the monitor btw. It could have even been stored offsite.. the monitor doesn't really tell us that much aside from that being a spot where they observed the feeds. They could even have a second or third monitor in another room connected to it too.

Sarah Nir explains the location in this video - https://www.youtube.com/watch?v=1gie0XVOFl0 and says "so I ran to the security guy, that I live in the ground floor, so it's first floor. So it's really a wall separated between my apartment and the security guy." She also confirmed he heard the sound, which would make sense if he was located closer. I sort of bet from her description that the security guy was actually in one of the manager offices and he also had access to the monitors in there, and that's perhaps where the drives/servers were located. Usually they're behind a locked door and then a locked closet as well to keep people from tampering with them.. and they're almost never just tucked away behind a front desk. It's also very unusual to have a security monitor that's in your front lobby that shows all of your camera locations as this makes it too easy for anyone trying to slip past them.. which tends to be trivial if you've seen the entire feed. I bet that front desk monitor only showed a feed of the front driveway by default. The front desk was also probably staffed by a valet guy really, instead of security. They also had a 24/7 concierge that may have used that desk. But security, valet and concierge seem like too many people to share that one desk.

In the notes from one of the 2020 meetings they mentioned that they were going to rearrange the manager offices as part of their 40 year re-certification, and it might have already been reconfigured from the original plans. It being around the recreation/party room sort of makes sense.. since they only allowed access to it with reservations and it was only open certain hours. I'm still wondering what happened to the security guy and if he made it out alive, since he hasn't done any interviews.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (jbourne8 (Computer)9 Jul 21 23:57)

since he hasn't done any interviews.
He is probably being paid well not to do any interviews...

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (SFCharlie)

He is probably being paid well not to do any interviews...

SHE did survive by crawling out the valet window and went back in to help residents out through the lobby rubble.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

One of the many plans out there showed a management office on the eastern side of the gym. I think it was either in recent permits or the 40 year recert stuff. It was where apartment 110's living room would have been, if that part wasn't configured as saunas, locker rooms, and gym. That would be literally through the wall from the Nir's bedrooms in 111.

If the servers were in there, they are still deep in the pile. If there's sufficient value in them, hard drives can prove to be very robust and data potentially recovered from them. Basically, as long as the drives just got buried, soaked, and the circuit board destroyed, but didn't take a catastrophic direct hit, the data may be recoverable.

Edit: See page 39 of 8777-collins-avenue---preliminary-review-plans-for-40-year-re-certification.pdf which shows the office in the gym. Dated April 2021, and I don't know if it was actually there or moving there during the refurbishment.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

My apologies for joining your forum when I am not an engineer (my name is a clue to my professional interest); I wanted to post this information regarding the location of a video of rescue efforts right after the collapse. The first photo is from this video. I have enhanced the photo.



The column in the foreground is labeled for parking space 96. It is a red column. There are a number of these in the garage walkthrough video and they all have a small box on the front (facing the driving lane) that may be either a fire alarm or an intercom to security; I do not know.

I combined two stills from the other video that had a garage walkthrough, to show this area before (which includes the column that unfortunately blocks one of the lanes when you get to the NW corner - parking in this area must have been a challenge). This view faces north and is the westmost area of the parking garage. You can see the column with 96 but a car blocks the red base of this column. However you can see the box on the front of that column and also the large dark pipe that runs E-W in front of this column seen in the rescue video. The parking garage numbers followed these rules: only two sides of a column were numbered. The numbers on the sides of the columns always faced the direction a car would be driving if coming into the garage to park. They always indicated the space before that column. The other numbers faced the front of the column and indicated the next space (on the far side of the column). In this image you can also see a fire extinguisher on the column past the 96 column but the 96 column blocks the view of the missing column next to it (seen in the rescue video) that is not on the garage floor plan. However we know it is there because that parking space is wider. Above the car behind the 98 column you can just see the column that is labeled 118.



This is another still from the rescue video showing the column labeled 117/118. The 117 is on the side and the 118 on the front facing the lane.



This view shows the view to the collapsed portion of the building with the fallen ceiling on the east, and is underneath the 05 and 04 units. The 05 units were the corner units and the 04 units were just to the east on the north-facing side of the building. I have marked up the garage floor plan below to indicate the view seen here. This is not a view towards the lobby and does not provide any information regards collapse in that area of the building. I have added to the floor plan the fire extinguisher, missing column, direction of the parking spot numbers on the columns, the point of view of the camera which is looking to the northeast. I included a second floor plan showing the line between the collapse and the remaining building, which is how I was able to note this location on the garage floor plan.







RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I don't know if it's just me, but I would be embarrassed to take photos like the ones I've seen posted.

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Tropmet - nice job, I believe this is all correct. Only slight tweak is where you have the red failure line would move slightly to the left and be on line E. It looks like the E columns stopped the further westward collapse and then there is a slight jog east to the shear wall which stopped the failure to its west. I too came to the conclusion there was a mystery column next to spot 117. It's presence is intriguing but probably insignificant, maybe original construction or some undocumented retrofit in the last 40 years?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Weird, where is the source on the security guard surviving? I haven't seen anything about that.. I thought his name was Jose.

Since the condo probably hired a company to install their security cameras, it's also possible it was stored off site on a backup too.. but it can take some time to pull up old video feeds from storage and prepare them in a way you can send out to a customer. Now that there are so many lawsuits too, they might not release them publicly. I also think that it's possible that we won't actually see much on them.. especially since it seems like the security guard didn't. Down in the garage they were most likely pointed towards entrances like the entrance you drive into, the elevators, I think there was a backdoor to the beach, the stairwell entrances, etc. All we'll probably see down there are the cameras getting knocked out. Upstairs they were also mostly focused on the entrances too, but I think I saw one that was pointed at the pool deck. Usually these systems have some decoy cameras that aren't really on though, especially outside of the building. There are also some notes in that 2020 doc about how around 4 of the cameras weren't operational, and it's not clear if they were fixed. We might not get any more videos that what are out now, it's hard to say.

Also, as far as I know you can drop or crush a hard drive to the point that the data isn't retrievable btw. This is actually a good way to destroy the data on a drive if you want it to be gone for good.. some companies use this method. It's not as effective as shredding, but the equipment to do it is pretty cheap.

One thing I'm a bit curious about too, is where are these storage units they keep referencing in docs? It sounds like they were in really bad shape, and were somewhere down in the garage.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (MJCronin (Mechanical)9 Jul 21 21:41)


Yes there are limitations on what information GPR can provide to us and reinforcing bar diameter information would be one of them. As with all NDT each method has its strength and weakness. But what GPR is exceptional at is identifying if rebar IS present and Accurately (+- 1/4”) identifying its location. This is extremely useful in identifying if the correct number of bars were placed in the correct locations. Example being, if 25% of the column strip bars are located at each column or at any other critical locations. Collar ties etc… [on a side note there are techniques GPR can use to estimate bar diameter]

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

My comment about the photo quality was not in reference to a specific poster... but, in general the photos provided and posted lack detail, and it was a general comment and not a complaint.

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Found this pic that was taken just after the collapse by a resident on the 8th floor in the part of the building that remained intact:




To my knowledge, this is the only photo in the public domain (for the moment) of the interior post collapse. Story here:

https://autos.yahoo.com/paris-wife-4-500-miles-201...

“NOOK-yoo-ler. It’s pronounced NOOK-yoo-ler.”

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote:
"One thing I'm a bit curious about too, is where are these storage units they keep referencing in docs? It sounds like they were in really bad shape, and were somewhere down in the garage."

It is. It is the triangular area to the far west. It it more-or-less under the front landscaping.

BKNJ

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

JBourne,

This building likely didn’t invest massively in anything.

That means:

1. The guard and the front desk person were one and the same. There was no security guy in a back room and a desk guy as well.

2. There was no meaningful separation of video storage from video monitoring. Most NVRs contain their hard drive, and most are now using Cat-# Ethernet cable. Most likely, this building had a couple of 16 channel NVRs with built-in drives and a 10-20 day storage. These cameras are designed to spot package thieves, not collapses, and NOBODY is spending the money to create an off-site archive of 32-64 channels. Certainly, not this condo.

3. Most cameras over $100 support an onboard storage card.

Solid state storage, like flash or thumb drives, are almost always recoverable. Hard drives are fairly easily recovered, even after a building collapse. Not quite as easily as an intact solid state or thumb drive, but NIST definitely has labs that can pull unencrypted footage off a hard drive platter.

Remember - airline black boxes survive 300mph+ crashes. The fastest moving object in this collapse was 60mph. I would expect them to recover video not just from the security system but also dozens of cell phones, and directly from any cameras equipped with onboard storage and with a card in them.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8)

Also, as far as I know you can drop or crush a hard drive to the point that the data isn't retrievable btw. This is actually a good way to destroy the data on a drive if you want it to be gone for good.. some companies use this method. It's not as effective as shredding, but the equipment to do it is pretty cheap.

The frame of a hard drive gives it a little protection. If it basically just gets buried without taking a huge direct impact, there's a moderate chance that the platters are intact. Those rigid metal platters with a magnetic coating can be extracted and read with specialist equipment.

Quote (jbourne8)

One thing I'm a bit curious about too, is where are these storage units they keep referencing in docs? It sounds like they were in really bad shape, and were somewhere down in the garage.

The west side of the garage, under the front garden type space on Collins Ave, had a large storage room with lockers. The slab there sounded like it had major issues from the planters. I guess the slab there was permanently damp, at least since the waterproofing failed. The automatic sprinklers in the planters would basically guarantee it.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2

Quote (jbourne8)

Weird, where is the source on the security guard surviving? I haven't seen anything about that.. I thought his name was Jose.

Her name is Shamoka Ferman and she’s had a very difficult time psychologically. Working the overnight shift, most residents had never met her until that night, none knew her name. It wasn’t until a few days ago Raysa Rodriguez (907) spotted her near the site and immediately took her to the assistance center. It was there Sra. Monteagudo (611 shown in the photo with Ms. Ferman) immediately ran up to thank her for saving her life. Unfortunately people incorrectly refer to her as a male. Worse still, her employer, Securitas made no attempts to check her status nor did anyone from CTS Management.

Quote (Js5180)

This building likely didn’t invest massively in anything.

That means:

1. The guard and the front desk person were one and the same. There was no security guy in a back room and a desk guy as well.

2. There was no meaningful separation of video storage from video monitoring. Most NVRs contain their hard drive, and most are now using Cat-# Ethernet cable. Most likely, this building had a couple of 16 channel NVRs with built-in drives and a 10-20 day storage. These cameras are designed to spot package thieves, not collapses, and NOBODY is spending the money to create an off-site archive of 32-64 channels. Certainly, not this condo.

3. Most cameras over $100 support an onboard storage card.

Solid state storage, like flash or thumb drives, are almost always recoverable. Hard drives are fairly easily recovered, even after a building collapse. Not quite as easily as an intact solid state or thumb drive, but NIST definitely has labs that can pull unencrypted footage off a hard drive platter.

The Security equipment was nearing 20 years old with very little in the way of upgrades over its life. The Li-Ion Fire from the crushed Tesla that took days to control certainly didn’t help matters much.

It seems people have the impression that this was a luxury, high-end condo building when it was not the case. In an area where oceanfront condos/apartments are selling in the $2,000 - $3,000 per sf/2 range, CTS was under $400 and represented the bottom of the market.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Oh true, I had forgotten about how old this system probably is. Most security packages these days come with offsite backups because they can also send the video to law enforcement so you don't have to worry about that. But yea, they probably didn't have anything modern. I hadn't even considered that they were so cheap and old that they might not be recording video too.

And wow, I hadn't heard about the Tesla.. that's awful. Wasn't it parked in spot 78? Is it possible that it actually caused the collapse? I've read before that they can catch on fire with a very slight crash into them, and they can easily get hot enough to cause concrete to be unable to hold a load.. and quickly. I looked at the tiktok video, but it's impossible to tell if there's a fire going on in it. I figure they would have seen it.. but perhaps that spot could have been just outside of their view. It seems like the only person that was in the garage after midnight was Eric Zion, but he has a strange story about the power being out in his apartment at 10pm and checking into a hotel instead. He only stopped by to park his car in the garage around midnight and get his electric scooter.

There's also this photo of the building internally too btw, taken by the resident in 705.. I think the door on the left is 704 -


He also took a video from the balcony too, in this article - https://nypost.com/2021/06/27/florida-tower-surviv...

The story from 904 is pretty horrific too.. pretty sure this hasn't been posted yet either - https://www.nbcnews.com/news/us-news/mother-daught... It says - “In the middle of the night, my daughter woke up because she heard a strange noise, and when she woke up, the building was shaking,” said Angela Gonzalez's mother, Kathleen Gonzalez. “She started screaming for them to get up and get out, and she just ran with her daughter, pulled her daughter by her arm, when they got out the front door, they didn't even go five feet, and it fell down to one floor below,” she said. They are the same family whose cat was found today.

It's interesting too that the most major points of damage - the pool equipment room, Raysa's leaky parking spot and the storage units all seem to be outside of the collapsed area. All that was under the collapse were a few puddles, old epoxy fixes that weren't done well, and there are those lawsuits from the tenant in 112 about water damage in 2001 and 2015. It really makes you wonder how the inspector missed this if the columns had signs of puncture sheer failure too. In the docs it seems pretty clear that he was fine with delaying that part of the project because they wanted to use the pool.

Thanks for the info on the security guard too.. she has a gofund me and I'm going to go pass it around a bit - https://www.gofundme.com/f/champlain-towers-collap...

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Which condos are doing off-site backups of days/weeks of security video? I’m gonna say zero.

Is there any evidence that a Tesla was parked in spot 78?

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I’m sorry - this just isn’t sitting well:

“Unfortunately, her only posession in life was the car her deceased mother gave her that was in the visitors parking next to the pool area.”

This is the security guard. She didn’t live in the building. Why is the car her only possession?

Please tell me if I’m missing something, but there are 150 residents and families of residents of this building that have bigger problems - many of them having lost lives or loved ones.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

6

Quote (1503-44 (Petroleum) 9 Jul 21 16:53 .. if Geezer is around ... his translation the other day was perfect, so maybe he could help out till I get back to it. Gotta run right now. https://www.youtube.com/watch?v=jGUEwj-Pi54

SFCharlie (Computer) (OP) 9 Jul 21 21:58 Quote (1503-44 (Petroleum)9 Jul 21 16:53) the best explanation I have yet to see so far. This is an excellent video, 300K views, 20K Likes WHAT was the CAUSE of the MIAMI building COLLAPSE | Teacher explains moment of COLLAPSE and FALL Worth your while to watch even without understanding the Spanish)


Truly a quick and dirty. Please forgive any errors.

CUAL fue la CAUSA del DERRUMBE del edificio de MIAMI | Profesor (Sergio Manes)
explica (el) momento del COLAPSO y CAÍDA

00:00 Este es el vídeo que nunca hubiese

[This is the video that I never would have]

00:03 querido hacer. Utilizar una catástrofe

[wanted to make. Using a catastrophe]

00:06 como ésta en la que murieron más de 150

[like this one in which more than 150]

00:09 personas aproximadamente por el derrumbe

[people died approximately by the collapse]

00:12 de un edificio para enseñarte a vos qué

[of a building to teach you what]

00:15 es lo que no tenés que hacer en tus

[it is that you do not have to do in your]

00:17 proyectos. Para que esto suceda, en estos

[projects. For this to succeed, these]

00:21 días se han tejido un montón de

[days there have been a bunch of]

00:24 hipótesis al respecto: desde las más

[hypotheses in this regard: from the most]

00:27 técnicas hasta las más sensacionalistas.

[technical to the most sensationalist.]

00:30 En donde, por ejemplo, se dice que entre

[Where, for example, it is said that, among]

00:34 las más técnicas la cantidad de aires

[the more technical, the number of air]

00:37 acondicionados que había en la cubierta

[conditioners that there were on the roof]

00:40 provocó el colapso de una estructura que

[caused the collapse of a structure that]

00:42 no estaba preparada para ese peso o de

[was not prepared for that weight or among]

00:45 las más sensacionalistas que querían

[the most sensationalist that somebody wanted]

00:47 matar a la hija de Trump o que querían

[to kill the daughter of Trump or that they]

00:50 acabar con los archivos de John McAfee

[wanted to destroy the files of John McAfee]

00:52 que supuestamente estaban ocultos en

[that supposedly were hidden in]

00:55 este lugar o que había sido un socavón.

[this place or that there was a sinkhole.]

00:57 Bueno, nada de esto pasó,

[Well, none of that happened,]

00:59 nada de esto pasó y hoy te voy a mostrar

[none of that happened and I am going to show]

01:01 exactamente qué fue lo que pasó y te lo

[exactly what happened and I will]

01:04 voy a demostrar con hechos

[demonstrate it with physical facts]

01:06 físicos o algunos experimentos. Acá te

[or with some experiments. I am going to]

01:09 voy a mostrar exactamente por qué razón

[show exactly why]

01:12 se cayó este edificio en Miami.

[this building collapsed in Miami]

01:22 Ha habido muchos testigos presenciales-

[There have been many eyewitnesses]

01:25 de este colapso pero el que yo considero

[of this collapse but the one (testimoney) I consider]

01:27 más importante es el de la señora

[to be most important is ]

01:29 Adriana Sarmiento quien junto a su

[that of Adrian Sarmiento, who along with her]

01:31 esposo escucharon el primer estruendo y

[husband heard the first boom and]

01:35 empezaron a advertir a los vecinos que

[started to warn the neighbors that]

01:38 se asomaron a los balcones por el mismo

[looked out their balconies because of the same]

01:40 estruendo que bajaran del edificio que

[boom that they should get out of the building that ]

01:42 el edificio (se) iba a colapsar. Hasta el

[the building was going to collapse. At that]

01:44 momento, la cámara de seguridad del

[moment, the security camera of the]

01:46 edificio vecino todavía no había

[neighboring building still hadn't]

01:48 registrado ningún rastro del derrumbe

[registered any trace of the collapse]

01:52 que a partir de ese primer estruendo

[that beginning from that first boom]

01:54 demoró tan sólo un minuto en producirse.

[took only one minute to happen.]

01:57 La señora Sarmiento relata que había

[Mrs. Sarmiento tells that she had]

02:01 descendido de su habitación del hotel,

[come down from her room in the hotel,]

02:02 que estaba contiguo al edificio del

[that she was next to the Surfside]

02:05 Surfside y que, estando en la calle,

[building and that, being in the street,]

02:08 escuchó un gran estruendo, prendió su

[she heard a loud boom, turned her]

02:11 teléfono celular y grabó esto. En este

[cell phone on and recorded this. In that]

02:14 vídeo podemos observar como todavía el

[video we can observe how the building]

02:16 edificio está en pie y ella filma a

[was still standing and she films a]

02:20 través del estacionamiento un chorro de

[stream of water through the garage entrance]

02:22 agua que se ve cayendo que no es de la

[that can be seen falling that is not from the]

02:25 piscina y

[pool and]

02:26 escombros que se ven. Inmediatamente

[rubble that is visible. Immediately]

02:28 empieza a pedirle a todos los vecinos

[she starts asking all the neighbors]

02:31 que se asomaron a los balcones para ver

[that looked out their balconies to see what]

02:34 qué había sido ese estruendo que bajen

[the loud boom was to come down that]

02:36 que el edificio se iba a derrumbar. Cosa

[the building was going to collapse. That]

02:39 que ocurrió al cabo de un minuto.

[happened after about a minute.]

02:43 La secuencia de vídeo captado por la

[The video sequence captured by the]

02:45 cámara de seguridad nos muestra, en

[security camera shows us,]

02:47 primer lugar, la caída de un tramo del

[in the first place, the fall of a part of the]

02:49 edificio del lado de la pileta.

[building next to the pool.]

02:52 Inmediatamente después de esto cae la

[Immediately afterwards, the]

02:55 parte que da hacia el lado de la calle,

[part facing the street,]

02:57 es decir enfrentando al hotel en donde

[that is, acroos from the hoter where]

02:59 se alojaba la señora Sarmiento. Queda

[Mrs. Sarmiento was staying. Only the]

03:02 solamente en pie el resto del edificio a

[part of the building to the]

03:06 la izquierda y un tambaleante cuerpo que

[left is still standing and a swaying body that was]

03:08 quedó al lado del resto del edificio que

[left of the rest of the building]

03:11 se bambolea y finalmente (se) colapsa. ¿Qué

[sways and finally falls. What]

03:15 ocurrió? El primer estruendo no fue ni

[happened? The first boom was nothing more]

03:18 más ni menos que el colapso de toda esta

[and nothingless than the collapse of all]

03:21 losa que se ve acá, que falla por punzonamiento.

[of this slab that can be seen here, that fails by punching shear.]

03:24 Fíjense como el nivel de losa en

[Look how the level of the slab in]

03:27 realidad es este que está acá y como ya

[reality is this that is her aand how now one]

03:30 en esta parte se ve que la losa

[can see how in this part the slab]

03:32 desciende y desciende llevándose consigo

[falls and falls taking with it]

03:36 todos los vehículos como este que se

[all the cars like this one that one]

03:38 puede apreciar acá que quedó mitad de la

[can see was left half on one]

03:41 losa que quedó en su lugar y mitad en la

[slab that stayed in its place and half on one]

03:44 losa que (se) colapsó. Acá se puede ver el

[slab that fell. Here you can see]

03:46 desprendimiento de la losa

[the detachment of the slab]

03:48 que debiera continuar acá hacia este

[that should continue here towards]

03:50 lado. Inclusive en las columnas se ve el

[this side. Additionally, you can see on the columns]

03:54 lugar en donde estaba la losa

[where the slab was connected]

03:55 originalmente. Esta es otra vista del

[originally. This is another view of the]

03:58 mismo lugar en donde se puede ver el

[same place where one can see the]

04:01 lugar del anclaje de la losa con

[place where the slab was anchored]

04:04 respecto a estas columnas y como esta

[to the columns and how ]

04:06 losa completa desciende esta distancia.

[this slab fell this whole distance.]

04:09 Estimo yo alrededor de 2 metros, es decir,

[I guess around 2 meters, that is,]

04:12 toda esta parte de la planta baja

[this whole part of the lower level]

04:15 (se) colapsa y cae sobre el

[collapsed and fell on the]

04:18 estacionamiento que está abajo

[parking level that was below it]

04:21 aproximadamente de esta manera. Este es

[approximately in this way/ This is]

04:24 el comienzo de la catástrofe. ¿Por qué

[the beginning of the catastrophe. Why]

04:27 falla esta losa? Falla por lo que se

[did this slab fail? It failed due to what is]

04:29 conoce como punzonamiento. El

[known as punching shear. The]

04:32 punzonamiento es cuando una losa (se) apoya contra(sic)

[punching shear is where a slab is supported]

04:36 una columna y

[by a column and]

04:39 la columna pasa de lado al lado. ¿Por qué

[the column punches through from one side to the other. Why]

04:43 se produce este esfuerzo? Se produce por

[does this happen. It happens due]

04:45 una carga puntual sobre una losa. Es

[to a point load on the slab. In other]

04:48 decir, la fuerza de la losa no alcanza a

[words, the load of the slab is not]

04:51 repartirse para trasladar esos esfuerzos

[transferred to the column and it fails in this manner.]

04:54 a la columna y cede de esta manera. ¿Qué

[What is it]

04:57 es exactamente lo que vemos acá? Esta

[exactly that we see here? This column]

04:59 columna pertenece al nivel de abajo,

[belongs to the lower level,]

05:02 pertenece al subsuelo. Acá lo podemos ver

[it belongs to the basement level. Here we can see]

05:05 con absoluta claridad por ejemplo. Acá

[with absolute clarity, for example. Here]

05:10 uno dos tres cuatro cinco seis y

[one two three four five six and]

05:16 probablemente otras siete y ocho que no

[probably another seven and eight (columns) that we]

05:19 vemos porque quedaron sepultadas por el

[can't see because they were buring by the]

05:21 derrumbe del edificio. Para evitar el

[collapse of the building. To avoid]

05:24 punzonamiento se utilizan dos métodos.

[punching shear two methods are used.]

05:26 El método más tradicional es este. El de

[This is the traditional method. Beams are]

05:30 utilizar vigas que sean las encargadas

[used to spread the loads]

05:32 de repartir los esfuerzos de la losa

[from the slab]

05:35 hacia la columna. Suponiendo que eso no

[to the column. Supposing that that is not]

05:38 se haga tenemos esta otra opción que es

[done we have another option that is]

05:41 la losa plana con ábacos y capiteles

[the flat plate with drop panels and capitals]

05:45 en donde el ábaco se calcula como parte

[where the drop panel is calcualted as part]

05:49 de la losa. Es decir, la losa en este punto

[of the slab. In other words, the slab at that point]

05:51 se calcula mucho más gruesa de lo que es

[is calculated to be much thicker that it is]

05:55 en el tramo por ejemplo y el capitel se

[in the span for example and the capital is]

05:59 calcula como parte de la columna. Sin

[caculated as part of the column.]

06:01 embargo, no podemos verificar por qué

[Nevertheless, we cannot verify why]

06:04 razón se produjo este punzonamiento

[the punching shear happened because]

06:05 porque la losa en este momento está

[the slab at this moment has]

06:08 colapsada. Lo más lógico sería visitar el

[collapsed. The most logical thing would be to visit]

06:11 estacionamiento y encontrar todas estas

[the parking level and find all of these]

06:14 vigas. Sin embargo si estas vigas

[beams. However, if these beams]

06:16 hubiesen estado no habría razón de

[had been there there would have been no]

06:19 punzonamiento. Lo lógico entonces

[punching shear. The logical thing then]

06:21 hubiese sido encontrar una estructura de

[would have been to find a structure of]

06:23 esta naturaleza por encima de las

[this kind over the]

06:25 columnas pero mucho me temo que nos

[columns but I'm afraid that we]

06:27 vamos a encontrar con esto. ¿Por qué digo

[are going to find this. Why do I say]

06:30 esto? Porque el edificio demuestra, al

[this. Because the builiding shows, as its]

06:33 quedar expuesta su estructura, que no

[structure was exposed that it did not]

06:36 posee vigas. No sé en el sótano, porque no

[have beams. I don't know in the basement, because I]

06:39 las puedo ver, pero en el edificio,

[can't see them, but, in the building,]

06:40 fíjense esto, a lo largo de toda esta

[look at this, along this whole]

06:44 imagen, que no es ni más ni menos que una

[image, that is nothing more nor less than]

06:46 radiografía de la estructura del

[an x-ray of the structure of the]

06:48 edificio, no se aprecia

[building, one cannot see]

06:51 un rastro de vigas. Por ejemplo acá, en

[any trace of beams. For example here, where one]

06:54 donde se ve el rastro de las losas que

[can see the trace of the slabs that]

06:57 llegan directamente a la columna, lo que

[connect directly to this column, that]

07:01 se esperaría acá es ver mínimamente

[one would expect to see here minimally]

07:04 algún rastro de que ahí hay una viga, de

[some trace that there was a beam, that]

07:07 que acá hay una viga, lo cual me hace

[here there would be a beam, which makes me]

07:11 prácticamente asegurar que si este

[assert that if this]

07:14 comportamiento fue en el edificio, es

[was the case in the building, that is]

07:16 decir, en las alturas, a nivel de planta

[at the upper levels, at ground level]

07:19 baja y subsuelo no había ningún tipo de

[and in the basement there was nothing like]

07:22 viga. De otra manera, no se podría haber

[a beam. Otherwise, the punching shear]

07:23 dado ese punzonamiento. Por lo tanto, la

[would not have happened. Therefore, the]

07:26 base de lo que dio origen al derrumbe

[root cause of what cause the collapse]

07:28 de los edificios fue la falta de vigas o

[of the buildings was the lack of beams]

07:33 de ábacos y capiteles en las columnas

[or drop panels and capitals on the columns]

07:35 para sostener la losa que cubría el

[to support the slab that covered]

07:38 estacionamiento. Pero esto no es todo.

[the parking area. But that is not all.]

07:40 Porque el hecho de que (se) colapse una losa

[Because the fact that a slab collapsed]

07:43 en este lugar no tiene por qué

[in this place should not have]

07:45 comprometer a todo un edificio que venía

[compromised the whole building that was]

07:48 en esta posición. Entonces, ¿por qué razón

[in this position. The, what was the reason]

07:53 se desploma el edificio? Este es el

[for the building to fall? This is the]

07:56 edificio antes del colapso.

[building before the collapse.]

07:58 Este es el sector entonces de la losa

[This is the sector where the slab]

08:01 que falla y cae. Entonces se desploma de

[fails and falls. Then it falls in this]

08:05 esta manera y estos autos son los que

[manner and these cars are the ones that]

08:08 caen junto con la losa. Este es el primer

[fall together with the slab. This is the first]

08:11 estruendo. Es el estruendo que oye la

[boom. It is the boom that]

08:13 señora Adriana y a través de la entrada

[Mrs. Adriana heard and throught the entrance]

08:16 de las cocheras percibe todos esos

[to the parking garage she can see the]

08:21 escombros y el agua cayendo. Mucho se ha

[rubble and the water falling. Much has been]

08:25 hablado del agua, todos diciendo que era

[said about the water, with all saying that it]

08:27 el agua de la piscina. Sin embargo, no es

[was the pool water. However, it isn't]

08:28 el agua de la piscina, es el agua del

[the pool water, it is the ]

08:31 jacuzzi que muy probablemente rompe una

[jacuzzi water that very likely burst a]

08:35 cañería de desagüe y cae sobre esta zona.

[drain and fell over this zone.]

08:38 Tal es así, en las fotos aéreas el día

[Such it is, that in the areal photos from the day]

08:41 después del desastre se ve claramente

[after the disaster it can be seen clearly]

08:43 como el jacuzzi está vacío. Esta es la

[that the jacuzzi is emptly. This is the]

08:47 línea de quiebre de la losa y la pileta

[line where the slab broke and the pool]

08:49 no ha bajado en lo más mínimo su nivel.

[has not lost any water.]

08:52 Ahora, ¿por qué razón se produce el

[Now, for what reason does]

08:55 colapso de toda esta sección del

[the collapse of this entire sectrion of the]

08:58 edificio inmediatamente después del

[building happen immediately after the]

09:01 derrumbe de esta losa?

[fall of this slab?]

09:03 Para explicar esto por un instante vamos

[To explain that, we are going to]

09:05 a prescindir de todo aquello que no sea

[remove everything that is not]

09:07 estructura del edificio, es decir, lo que

[part of the structure of the building, that is, what]

09:10 lo sostiene en pie al edificio. Por lo

[keeps the building standing. Therefore,]

09:13 tanto ocultamos autos, barandas y piel

[we will hide cars, raililngs and the skin]

09:17 del edificio. Nos quedamos con la mera

[of the building. We are left only with]

09:20 estructura. Si analizamos el primer

[just the structure. If we analyze the first]

09:23 colapso cuadro a cuadro nos vamos a

[collapse frame by frame we will]

09:25 encontrar con lo siguiente. En el cuadro

[find the following. In Frame]

09:27 0 se inicia el derrumbe y ya en el

[0, the collapse begins and already in]

09:30 cuadro 1 se puede ver cómo se ven

[frame 1 it can be seen how all the]

09:32 comprometidas todas las secciones del

[sections of the building have been compromised.]

09:35 edificio. Concretamente lo podemos ver en

[Concretely, we can see it in the]

09:37 las ventanas (están iluminadas) que

[windows (they are lit) that]

09:40 empiezan a descender.

[start to fall.]

09:42 Ahora fíjense que el colapso empieza y

[Now look at how the collapse starts and]

09:44 se detiene por una décima del segundo.

[then it pauses for a tenth of a second.]

09:47 Cuadro uno dos tres cuatro cinco seis y

[Frame one two three four five six and]

09:51 ahí ya está detenido.

[there it has paused.]

09:53 Es decir, en el 4 comienza la detención

[That is, in (frame) 4 the pause of]

09:57 del derrumbe por un segundo. 1 2 3 4,

[the collapse begins for a second. 1 2 3 4,]

10:02 ahí se detiene. Ya no baja más del 4 al 5.

[there it stops. It doensn't fall any from 4 to 5.]

10:04 Fíjense que no baja en el 6 y tampoco

[Look, it doesn't fall in 6 and also]

10:08 en el 7. Es como que vuelve a empezar a

[in 7. It's like it starts to]

10:11 bajar y en el 8 se manifiesta

[fall and in 8, the collapse accelerates.]

10:13 fuertemente este descenso. Se detiene

[It pauses]

10:16 nuevamente y vuelve a caer. Vamos a verlo

[anew and falls again. Let's look at it]

10:18 en cámara normal y se ve claramente como

[at the normal speed and it can be seen clearly how]

10:22 se detiene, se detiene y cae. Lo vemos de

[it pauses, it pauses and falls. We look at it]

10:25 nuevo, se detiene y cae una vez más. Se

[again, it pauses and falls one more time. It]

10:28 detiene y cae. ¿Por qué sucede esto? Porque

[pauses and falls. Why does this happen? Because]

10:30 la estructura al bajar prácticamente un

[after falling one level the fall of the structure]

10:33 piso se detiene y luego se produce el

[pauses and then the definitive]

10:36 colapso definitivo. Como se puede ver en

[collapse happens. As can be seen in]

10:39 el vídeo el sector del edificio que cae

[the video, the section of the building that falls]

10:42 primero es este, arrastrando parte de lo

[first, is this one, dragging part of]

10:47 que tiene al costado, pero la falla se

[what is to its side, but the failure happens]

10:49 produce acá abajo. Fíjese que cae

[down here. You can see that it falls]

10:52 prácticamente completo salvo estas

[practically intact with the exception of]

10:54 partes de acá que se desgarran. Vamos a

[these parts here that are ripped apart. We are]

10:57 verlo más en detalle. Cae al medio y se

[going to look at it in more detail. The middle falls]

11:00 desgarran las partes de los costados acá.

[and the parts on the sides are ripped apart here.]

11:03 Se puede apreciar cómo esta parte es la

[You can see how this part is the]

11:06 que cae y trae arrastrando esta parte de

[part that falls and drags this part of the]

11:10 las estructuras vecinas. Por lo tanto la

[neighboring structures. Therefore, the]

11:13 falla está

[failure is]

11:14 acá abajo y, efectivamente, fíjense en

[here below and, effectively, observe these]

11:19 estas dos columnas de acá. Las columnas

[two columns here. The columns]

11:22 inicialmente fueron calculadas para esta

[were originally calculated for this]

11:26 luz en planta baja y para una luz que

[span in the lower level and for a span that]

11:30 debe andar más o menos por acá en el

[would be more or less this much in the]

11:32 subsuelo. Sin embargo, al desaparecer los

[basement level. Nevertheless, uppon the disappearace]

11:36 adiestramientos que generaban las losas

[of the supports that the slabs provided]

11:38 en ese lugar, la luz que antes era esta

[in this place, the span that before was this]

11:42 para esta columna ahora pasa a ser el

[for this column in now]

11:45 doble y esta columna no fue calculada

[twice as much and the column was not designed]

11:48 para tener esa altura y ¿cuál es la

[for that length and what do]

11:51 deformación que afecta a aquellos

[you call the failure that affects those]

11:53 elementos esbeltos que son sometidos a

[slender elements that are subject to]

11:56 compresión? El pandeo. Lo vimos hace dos

[compression? Buckling. We covered that two]

12:00 semanas. Flexión

[weeks ago. This is]

12:03 era esto.

[flexion.]

12:06 Pandeo

[This]

12:08 es

[is]

12:10 esto.

[buckling]

12:12 Vamos a verlo con un modelo a escala.

[Let's look at it with a scale model.]

12:14 (La) altura de la columna para la cual fue

[The length of the column for which it was]

12:17 dimensionada en donde por más fuerza que

[designed where no matter how much force]

12:20 yo le haga no hay ningún problema de pandeo.

[I apply, there is no buckling.]

12:22 Sin embargo, la misma sección de

[However, the same column section]

12:25 columna en el doble de altura en cuanto

[where the length is doubled as soon]

12:28 yo le ejerzo la misma presión,

[as I apply the same force]

12:31 falla por pandeo. Esto es lo que pasó en

[it buckles. That is what happened at]

12:35 el edificio Surfside. Estas dos columnas

[the Surfside building. These two columns]

12:38 fallaron por pandeo al perder la

[suffered buckling failure after losing]

12:41 riestra de este lado. Las columnas se

[the support on this side. The columns can]

12:44 pueden deformar en este sentido y

[be displaced in this manner and]

12:47 romperse. La rotura por pandeo es sin

[break. Buckling failure is without]

12:51 aviso. Se quiebra el doble tramo bajo y

[warning. The double length column span breaks]

12:54 cae el resto, hace pie por un instante la

[and the rest falls, the structure stands]

12:57 estructura y después se va obviamente

[for an instant and then it fails due obviously]

13:00 por una catarata de de esfuerzos para

[to an avalanche of loads]

13:03 los cuales la estructura no fue diseñada

[for which the structures was not designed]

13:06 y obviamente (se) colapsa. Lo que sucede a

[and obviously it collapses. What happens]

13:09 continuación no tiene mayor misterio.

[next is no mystery.]

13:11 Pasa lo mismo con las columnas del tramo

[The same thing happens to the columns]

13:14 de atrás.

[of the back side.]

13:15 Primero (se) colapsa esta parte. Cae la losa

[First this part collapses. The slab fails]

13:20 por punzonamiento. En segundo lugar,

[by punching shear. In second place,]

13:22 (se) colapsan estas dos columnas por pandeo,

[these two columns fail by buckling,]

13:26 produciéndose el desprendimiento de toda

[producing the detachment of all]

13:30 esta zona del edificio. Ya si en esa zona

[this part of the building. Now then in this zone]

13:34 la parte que está por detrás,

[the part that is behind,]

13:36 es decir, esta parte de acá atrás, esa

[that is, this part back here, this]

13:40 parte del edificio es sometido(sic) a

[part of the building is subject probably]

13:42 esfuerzos probablemente de flexo-

[to flexo-compressive forces]

13:44 compresión para la cual las columnas no

[for which the columns are]

13:47 estaban preparadas y también fallan

[not designed and they also fail]

13:50 llevándose toda esa parte del edificio

[taking with them this whole part of the building.]

13:53 consigo. Pero queda toda esta parte del

[This whole part of the building]

13:57 edificio todavía y esa ¿por qué cae? Porque

[remains and that (part) why does it fall? Because]

14:01 se mantiene en pie por un segundo y

[it stands for one second and]

14:04 luego (se) colapsa. Aparentemente (se) colapsa del

[then collapses. Apparently, the part]

14:07 lado de la pileta primero. Ahí se ve.

[next to the pool falls first. You can see it there.]

14:10 (Se) colapsa de este lado. Es decir que fallan

[This side collapses. In other words, the two]

14:12 y fallan parejas las dos columnas de

[lowest columns fail and probably fail at the]

14:15 abajo probablemente. Mientras tanto el

[same time. Meanwhile, the building continues to stand]

14:18 edificio se mantiene en ese momento. Ahí

[at that moment. There you]

14:21 se puede ver. Como el edificio se está

[can see it. As the building is]

14:23 casi como torsionando un poco, hasta que

[twisting a bit, until these]

14:26 se quiebran esas columnas y cae completo

[columns break and the whole block falls]

14:29 otra vez todo el bloque

[again as a whole]

14:32 y se desmorona. El resultado de ese

[and collapses. The result of that]

14:35 último desmoronamiento es todo esto que

[last collapse is all this that]

14:38 se ve acá. De hecho esta es la primera

[can be seen here. In fact, this is the first]

14:41 losa, acá se ve la segunda losa, la

[slab, here is the second slab, the]

14:44 tercera losa, la cuarta losa, etcétera.

[third slab, the fourth slab, etc.]

14:47 Todo esto otro que se ve por acá es

[Everything else that you see over here is]

14:50 producto de lo que fue el primer

[product of what was the first]

14:53 desmoronamiento. Y esto que se ve hacia

[collapse. And this that can be seen towards]

14:56 este lado es parte del segundo

[this side is part of the second]

14:58 desmoronamiento que llega a alcanzar con

[collapse that reaches with some rubble]

15:01 algunos escombros el hotel en donde

[the hotel where]

15:03 estaba la señora Adriana. Y en último

[Mrs. Adriana was staying. In last place,]

15:06 lugar, el causante de todo esto que fue

[the cause of all this is]

15:08 la rotura de la losa del estacionamiento

[the failure of the parking slab]

15:13 por punzonamiento. Ahora, ¿por qué razón

[by punching shear. Now, why did]

15:17 ocurre esto? ¿Que no hay intersticios

[that happen. That there no nooks]

15:21 adonde haya posibilidad de encontrar un

[where it is possible to find]

15:24 sobreviviente? ¿Por qué en colapsos

[survivors? Why is it that in similar]

15:27 similares quedan espacios?

[collapses spaces are left?]

15:30 Hay esperanzas de que acá adentro haya

[Is their any hope that in here someone]

15:33 quedado alguien y pueda sobrevivir acá

[may be found and could survive here]

15:36 acá o acá. Y ¿por qué esto no pasó en

[here or here. And, why didn't this happen]

15:41 Surfside? Hay una sola razón

[in Surfside? There is on reason]

15:45 y es la razón por la cual se derrumbó la

[and it is the reason why the first parking]

15:48 primera losa del estacionamiento y por

[slab collapsed and that]

15:50 la cual se produjo el pandeo de las

[caused the buckling of the]

15:54 columnas que derivó en la rotura de

[columns that caused these columns]

15:56 estas columnas y en el derrumbe de toda

[to break and in the collapse of this whole]

15:59 esta sección del edificio y por lo cual

[part of the building and that]

16:02 se provocó también esta torsión del

[caused the twisting of]

16:05 cuerpo que quedó aislado sobre la playa

[the part of the building that was left by itself towards the beach]

16:08 y que provocó también la falla de las

[and that provoked also the failure of the]

16:11 columnas de planta baja y la caída de

[lower level columns and the collapse of]

16:13 todo el edificio. Puede haber habido un

[the whole building. It could have been]

16:16 pésimo mantenimiento. La estructura se

[terrible maintenance. The structure could]

16:19 pudo haber visto debilitada por la

[have been weakend by]

16:21 corrosión

[corrosion]

16:23 en las varillas de hierro en la zona de

[of the rebar the area of the]

16:25 la piscina en donde estaban muy

[pool where they were]

16:27 expuestos. Se les veía en fotos que se

[exposed. One can see them in photos]

16:30 han publicado. Pudo ser que el salitre

[that have been published. It could have been]

16:34 del agua de mar también haya provocado

[the saltiness of the seawater that could also]

16:37 un deterioro muy rápido y muy avanzado

[have caused a rapid and advanced deterioration]

16:40 sobre el acero de la estructura. Pero

[on the steel reinforcement. But]

16:46 nada de esto hubiese sucedido pese a

[none of that would have happened in spite of]

16:50 todas estas sucesión de fallas si el

[all of these failures if the building]

16:55 edificio hubiese tenido vigas. El

[would have had beams. The]

16:58 edificio no tiene vigas. Esta es la

[building did not have beams. This is the]

17:03 imágen que recorrió el mundo.

[image that went around the world.]

17:06 Este es el mudo testigo de las causas

[This is the mute testimonty of what]

17:10 que originaron la caída de este edificio.

[caused the collapse of this building.]

17:12 Fíjense esta losa que viene por acá. No

[Look at this slab that is here. It doesn't]

17:17 tiene un solo apoyo en toda esta

[have a single support in this whole]

17:21 distancia. Cuando digo apoyo, me estoy

[span. When I say support, I am refering]

17:23 refiriendo a una viga mínimamente acá.

[to a beam at least here.]

17:28 Tiene que haber una viga que esté

[There has to be a beam that is]

17:30 soportando esta losa y que permita volar

[supporting this slab and that let's you cantilever]

17:35 este prácticamente metro 80 que tienen

[this practically 1.8 meters that these]

17:38 esos balcones de voladizo. Un metro 80.

[balconies have as overhang. 1.8 m.]

17:42 Este(sic), por ejemplo, es la vista del último

[This, for example, is the view from the last]

17:45 nivel del penthouse. Fíjense la distancia

[level of the penthouse. Look at the distance]

17:49 que hay. Desde este punto a este punto,

[that there is. From this point to this point,]

17:53 contemos las baldosas. Acá esa viene por

[let's count the tiles. Here this one comes]

17:56 ahí y tenemos 1 2 3 4 5 6 7 8 9 10

[her and we have 1 2 3 4 5 6 7 8 9 10]

18:03 11 baldosas. ¿De cuanto serán? ¿De 20 x 20?

[11 tiles. How big are they? 20cm by 20cm?]

18:08 Dos metros veinte de voladizo. ¿(V)os ves

[2.20 meters of overhang. Do you see]

18:12 alguna viga acá sosteniendo la losa o

[any beam hear supporting the slab or]

18:14 ves algún refuerzo que esté indicando

[some reinforcement that is called for]

18:17 que esa losa no va a fallar por

[so that this slab will not fail due to]

18:19 punzonamiento? Este es el interior de

[punching shear? This is the inside of]

18:22 uno de los departamentos. Se puede

[one of the apartments. You can see]

18:25 apreciar la mocheta de la columna. Pero a

[the column corbel(?). But this column]

18:29 esta columna no está llegando ninguna

[is not connected to a]

18:31 viga. Fíjense que la carpintería va de

[beam. Observe that the fenestration]

18:35 piso a techo. Es decir que el nivel de

[spans from the floor to the ceiling. In other words, the level of]

18:40 esta losa es el mismo nivel que el de

[this slab is the same level as this]

18:44 esta losa. Ustedes me dirán: ¿no es

[slab. You may ask: is this]

18:46 inaudito? ¿Cómo puede ser que una losa de

[unheard of? How can it be that a reinforced]

18:49 hormigón armado no esté apoyando sobre

[concrete slab not be supported on]

18:52 una viga, cuando va a enfrentar un

[ a beam, when it is going to be part]

18:54 voladizo de cerca de dos metros? Este

[ of an overhang of roughly two meters? This]

18:56 departamento es este departamento de acá.

[apartment is this apartment over here.]

19:01 Yo te invito a que busques algún rastro

[I invite you to find any trace]

19:05 de vida entre todos esos hierros

[of life among these twisted]

19:08 retorcidos, en donde se ven los ganchos

[pieces of steel, where you can see the hooks]

19:11 producto probablemente de un solape de la

[product probably of a lap splice of the]

19:14 armadura.

[steel reinforcement.]

19:14 Pero no hay rastro de vida. No hay vida. No

[But there is no trace of life. There is no life. There]

19:20 hay vida. Ahí no hay vida en ninguna

[is no life. There is no life in any]

19:22 parte del edificio. Todo el edificio son

[part of the building. The whole building is]

19:25 losas apoyadas sobre columnas: el error

[slabs resting on columns: a first]

19:30 de todo estudiante de primer año. Porque

[year student mistake. Because]

19:34 ya en segundo año, nadie puede cometer

[in the second year, nobody can make]

19:37 ese error y ustedes me dirán, bueno, ¿pero

[this error and you may ask, well, but it]

19:39 se mantuvo cuarenta años en pie? De la

[stood for 40 years. In the same manner]

19:42 misma manera que este edificio se

[that this building]

19:44 mantuvo cuarenta años en pie

[stood for 40 years]

19:48 este edificio de acá que es el gemelo

[this building over here which is the twin]

19:50 también se mantuvo 40 años en pie. Esa es

[also stood for 40 years. That is]

19:54 la torre norte. Tal vez ésta haya tenido

[the north tower. Maybe this one has]

19:57 un mantenimiento mejor que ésta y el

[had better maintenance than this one and]

20:01 punzonamiento no se llegó a dar en las

[punching shear didn't happen in the]

20:03 losas.

[slabs.]

20:05 Yo no viviría en esa torre. De hecho yo

[I would not live in this tower. In fact, I]

20:09 hice este vídeo y me preocupé

[made this video and it concerned]

20:10 fundamentalmente por este tema cuando vi

[me to the core in regards to this issue when I]

20:13 las fotos de lo que era el edificio

[saw the photos of what the building]

20:16 originalmente. Cuando uno ve esta foto, le

[was originally. When you look at this photo,]

20:19 llama inmediatamente la atención la

[the slenderness of the slab sections]

20:22 delgadez de los espesores de losa. Por un

[is immediately noticeable. On one]

20:25 lado que en esta parte de abajo

[side that in this lower part]

20:27 aparentemente esta losa estaría apoyada

[apparently this slab is supported]

20:30 en una viga que pasa por acá. He dicho

[on a beam that goes here. I've said]

20:34 sea de paso parece ser la única viga que

[perhaps in passing it seems to be the only beam]

20:36 hay en todo el edificio. Porque si se

[that there is in the whole building. Because, if you]

20:38 fijan, van a ver que todas las otras

[notice, you can see all the other]

20:40 losas están sobre el nivel de dintel de

[slabs are at the level of the lintel]

20:43 las carpinterías. Acá.

[of the fenestration. Here.]

20:46 Acá. Esta es la única parte en la que eso no

[Here. This is the only part where that]

20:49 sucede. Recién le calculamos el tramo del

[is not the case. Just now we measured the overhang]

20:53 voladizo alrededor de 2 metros 20 y

[at around 2.20 meters]

20:57 fíjense una baranda que tiene

[and observe a railing that is]

20:59 aproximadamente entre 90 centímetros y

[about between 90 cm]

21:01 un metro en relación al espesor que

[and 1 meter in contrast to the thickness]

21:04 tiene la losa. Estamos hablando de

[of the slab. We are talking about]

21:07 aproximadamente 15 centímetros de

[about 15 cm of]

21:10 espesor terminado que no es altura de

[finished section, which is not the section]

21:13 cálculo. En este caso supuestamente de

[of design. In this case, supposedly]

21:16 nuevo están apoyados (los voladizos) sobre una viga pero

[once again the overhangs are supported on a beam but]

21:18 en este caso no. En este tampoco. En este

[in this case no. In this one also no. In this]

21:21 y ningún otro caso. Ese espesor de 15

[and in no other case. The sections of 15]

21:24 centímetros es este que ustedes ven acá.

[centimeters is this one that you can see here.]

21:28 Mi pregunta es, si esa losa no está

[My question is, if this slab isn't]

21:31 apoyada, ¿en qué momento termina el tramo

[supported, where does the span end]

21:35 y en qué momento empieza el voladizo? ¿En

[and where does the overhand begin? Where]

21:38 qué momento tengo que subir los hierros

[do you place the rebar so that the]

21:40 para que esto trabaje a tracción en la

[upper part works in tension?]

21:43 parte de arriba? Y, supongamos que lo han

[And, let's suppose that they have filled]

21:46 llenado de hierros, cosa que se ve

[it with steel, something that clearly]

21:48 claramente que no es así, mismo acá,

[can be seen no to be true, same here]

21:52 mismo en todos estos tramos de columnas

[same in all of these lengths of complete]

21:56 completos que aparecen sin ningún rastro

[columns that can be seen without any trace]

22:00 de haber sido desprendido prácticamente

[of having been detached practically]

22:03 de nada porque se ve un poquito. Y

[from nothing because you don't see much. And]

22:04 fíjense esto es inaudito. Es decir, llega

[observe that this is unheard of. That is, it]

22:07 hasta acá. En realidad es un tramo. Es

[goes to here. In reality, it is a span. It is the]

22:08 todo la columna completa que va de piso

[whole complete column that goes from floor]

22:12 hasta el último piso cuando en realidad

[to the last floor when in reality]

22:15 ese encuentro se debería ver por lo

[that joint should be seen as least]

22:18 menos así, por lo menos vigas de 30

[like this, at least beams of 30]

22:22 centímetros.

[centimeters.]

22:23 La falta de vigas en una estructura

[The lack of beams in a structure]

22:25 genera esto. En primer lugar, las losas

[causes this. In the first place, the slabs]

22:29 pierden rigidez. Fíjense esto. Una losa

[lose rigidiy. Observe this. A slab]

22:32 sin vigas no lo puede soportar y ahora

[without beams cannot support it and now]

22:36 la misma losa, el mismo cartón pero con

[the same slab, the same cardboard but with]

22:40 vigas, con estos pliegues acá a los

[beams, with those folds here on the]

22:42 costados, genera rigidez.

[sides, generating rigidity.]

22:49 Gracias a estos bordes materializados

[Thanks to the borders that come into]

22:52 que le dan rigidez a la losa y no

[existense that give rigidity to the slab and]

22:55 solamente le dan rigidez a la losa, le

[not only give rigidity to the slab, they]

22:57 dan rigidez a todo el edificio. Miren un

[give rigidity to the whole buildings. Objserve a]

23:01 esquema estructural sin vigas en donde

[structural frame withou beams where]

23:05 está todo pegado. Esto resiste

[everything is glued. This one resists]

23:08 perfectamente y un esquema estructural

[perfectly and a structural frame]

23:11 con vigas, con vigas de cartón: el mismo

[with beams, with cardboard beams: the same]

23:15 material. Fíjense cómo se comporta este.

[material. Observe how it behaves.]

23:19 Fíjense cómo se comporta este.

[Observer how this one behaves.]

23:23

[Música]

23:24 Yo le voy a poner una vigueta, una

[I am going to put a beamlet, a beamlet]

23:26 sección de viguetas, esto debe estar

[section, this should]

23:28 pesando unos dos kilos y medio, arriba

[weigh 2 and a half kilos, on top]

23:31 de esta

[of this one]

23:33 nada.

[nothing.]

23:35 Le pondré eso más esto, nada.

[I'll put this one plus this, nothing.]

23:42 Ningún problema.

[No problem.]

23:46 A esta que no tiene vigas,

[This one has no beams.]

23:48 Vamos a tratar de que esté derechita.

[We're going to try to make sure it's straight.]

[Música]

23:52 Miren. ¿Cuánto va a durar? Ahí viene

[Look. How long will it last? There goes]

23:55 el colapso.

[the collapse.]

23:57

[Música]

24:08 Tristísimo.

[Very sad.]

24:11 ¿Por qué no le pusieron vigas?

[Why didn't they use beams.]

24:15 Yo solamente veo dos motivos: ignorancia,

[I only see two motives: ignorance,]

24:19 la persona que lo hizo dijo "ah no sabía

[the person that made it said "oh, I didn't know]

24:22 que había que ponerle vigas o no, esto

[that I had to use beams or not, this]

24:25 aguanta, o ..."

[will be enough support, or ..."]

24:27 Porque eso no se le puede haber pasado a

[Because that couldn't have happened to]

24:29 1 2 3 4 ¿Cuántos controles hay en el mismo,

[1 2 3 4 How many levels of review are there in the same,]

24:33 en la misma ciudad? La ciudad hace sus

[the same city? The city has its own levels]

24:36 propios controles, aprueba las obras, hay

[of review, it approves projects, there was an]

24:40 un arquitecto que firmó, hay un ingeniero

[architect that signed, there was an engineer]

24:42 que firmó, hay alguien que se encargó del

[that signed, someone was in charge of]

24:44 mantenimiento también y no dio aviso o

[maintenance also and din't say anything or]

24:47 no hizo nada para arreglar lo que ya se

[didn't do anything to fix what could already]

24:49 veía que pudo haber generado esta falla

[be seen could have caused a]

24:52 por punzonamiento. Ignorancia, yo la

[punching shear failure. Ignorance, I don't]

24:56 descarto.

[think so.]

24:57 Ambición. ¿Por qué ambición? Al no ponerle

[Ambition. Why, ambition. Not using]

25:02 vigas, la distancia de piso a techo puede

[beams, the distance from the floor to the ceiling]

25:06 ser significativamente menor porque no

[can be a lot less because there is]

25:09 hay altura de paso en ningún momento,

[no lack of headroom at any time,]

25:10 porque no hay vigas. Es decir, en esta

[because there are no beams. That is, in this]

25:13 situación, si yo me puedo ahorrar 30

[situation, if I want to spare 30 cm]

25:16 centímetros por piso, en una de esas en

[per floor, then I can]

25:19 la suma total puedo meter 13 niveles en

[fit 13 floor levels where]

25:24 donde la normativa por altura con vigas

[the total height if I had to use beams]

25:27 solamente me dejaría 12 niveles. Fíjense

[would only allow for 12 stories. Look at the]

25:30 la normativa en esta zona aparenta tener

[regulated height in this are that appears]

25:35 una altura que es más o menos ésta. Si

[to be more or less this one. If]

25:39 están todos los edificios alineados

[all the buildings are limited to]

25:41 sobre esa altura, al menos en la década

[this height, at least during the decade of the]

25:43 de los 80, este edificio tiene planta baja

[80s, this building has a basement]

25:45 más 1 2 3 4 5 6 7 8 9 10 11 12. Son 13

[plus 1 2 3 4 5 6 7 8 9 10 11 12. There are 13]

25:53 plantas en total contando la planta baja.

[stories in total counting the basement.]

25:56 Vamos a ver este edificio que está acá. Tiene

[Let's look at this other building over here. It has]

26:00 planta baja más 1

[basement plus 1]

26:02 2 3 4 5 6 7 8 9 10 11, es decir 12

[2 3 4 5 6 7 8 9 10 11, that is 12]

26:09 plantas en total. El desarrollista, el

[stories total. The developer, the]

26:12 inversor, el arquitecto que cobraba

[investor, the architect that charges]

26:15 por metro cuadrado o quien fuera, se

[per square meter or who ever it might be, would]

26:18 benefició ampliamente obteniendo una

[benefit themselvers considerably by]

26:21 planta más producto de quitar las vigas.

[putting in an extra floor as a result of omitting the beams.]

26:25 No digo que haya sido eso pero he visto

[I am not saying that that is the cause but I have seen]

26:28 casos como ese muchas veces que, en lugar

[cases like this one many times where, in place of]

26:31 de poner las vigas así, las ponen así y

[putting in beams like this, they put them like this and]

26:34 las llenan de hierros para por ejemplo

[they fill them with steel to, for example,]

26:37 ahorrarse un nivel en todo el alto del

[save themsleves room for another floor]

26:41 edificio. Así poder poner un nivel de más.

[in the building. That way they can have an extra floor.]

26:43 ¿Habrá sido esto?

[Was that what it was?]

26:45 A mí no me queda que pensar otra. Por

[I can't think of anthing else.]

26:47 ignorancia esto no puede haber sido. No puede haber sido.

[It wasn't ignorance. It could not have been.]

26:52 Y si lo fue, para eso estoy hoy acá, para

[And if it was, that is why I am here, to]

26:57 mostrarte a vos cómo no hay que hacer

[show you how not to do]

27:01 las cosas,

[things,]

27:03 para decirte que nunca firmes nada con

[to tell you that you should never sign]

27:07 lo cual no estás de acuerdo. Porque en

[that with which you are not in agreement. Because]

27:09 una de esas el desarrollista, al inversor,

[in one of these, the developer, the investor]

27:12 se esfuerza: "arquitecto necesita

[will make an effort: "Mr. Architect, I need]

27:14 una planta más" y te hacen firmar eso y

[an extra floor" and you are made to sign that and]

27:17 el responsable de eso sos vos. Que nunca

[you will be the one responsible. May it never]

27:21 te pase, que nunca nos pase que tengamos

[happen, may it never happen that one]

27:26 que cargar con la vida de 150 personas

[has to carry the life of 150 human beings]

27:30 en nuestra conciencia.

[on your conscience.]

27:35

[Música]

27:38 Hoy no hay sorteo, no hubo wilson. Este

[There is no lottery today, no ????. This]

27:41 (unintelligible) al principio es el vídeo

[.... at the beginning of the video]

27:43

[Música]

27:45 qué

[that]

27:46 no hubiese querido hacer. Toma conciencia

[I would not like to have made. Take notice]

27:49 por favor. La estructura es lo más

[please. The structure is the most]

27:51 importante.

[important thing.]

27:55 Haremos un minuto de silencio por las

[Let's have a minute of silence for the]

27:58 víctimas de esta tragedia.

[victims of this tragedy.]

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Js5180 - Condos don't do security backups or even install their own security system.. they hire a security company and lots of them include offsite backups these days. I don't really know anything about security tech 20 years ago though. Some security companies will do all of the interfacing with law enforcement too though.. and if you've ever had to prepare security footage for them it's actually a ton of work that most people can't do properly. That's why they'll sometimes hire a company to handle it all beyond just the install.. and offsite backups are actually easier and quicker for them to deal with. Security guys can watch the video and call 911 to report problems, but lots of them struggle to edit videos. If the video is long enough (around 2 minutes of hd video) you have to also re-encode it down to a smaller size or you won't be able to email it as a single video. The police won't usually take an entire hard drive from you for simple burglaries, it has to be a major crime for them to help you that much.

And the security guard is probably the poorest person that was in the building. Without a car, she probably can't get another job. Perhaps she's living with friends, etc.. no one knows her personal story. They all nearly died, including her, which is extremely traumatic and difficult to come back from. Everyone else is getting lots of assistance btw.. the city has setup a receiver to hand them out payments of 2-10k, and between the insurance and selling of the property a judge says they own at least 100 mil (48 in insurance policies and he estimates they can sell the property for 50-60 mil). Money can't do much anyways when you've lost a loved one, all it can do is help these people get their lives back together. If it doesn't sit well with you, don't donate.. it's that simple.

And nah, there was no proof that there was a Tesla in spot 78.. but it had a cover that made it look like it could have been one. Just odd that it was down there when those cars are so dangerous around concrete.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (jbourne8 )



Gimena Accardi and Nicolás Vázquez were the last two people in the garage and had just entered the elevator to go up to their unit for the night when the plaza level parking collapsed. At the same time, the fire alarm activated causing the cars to auto recall to the lobby level. Nicolas stated “we only went up one floor.” They were provided expedited replacement documents and a private jet through a well connected friend and returned to Argentina rather quickly. The Zion events/timeline are peculiar but easily rationalized, but deserve scrutiny. The other two, starting to raise red flags given the tiktok video.

The Tesla was crushed and when the battery cells are damaged, they tend to go into thermal runaway as a result. The fire seemed not to start until the next high tide when salt water would be back flowing in from the storm drains. This only makes the fire risk worse.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Js5180)

Which condos are doing off-site backups of days/weeks of security video? I’m gonna say zero.

I do on all my buildings with multiple backups on-site and remotely. Also have real-time remote connection with independent power and data links. I’m not the only one in Miami that does this, but it’s not extremely common either.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Alright, gotcha. I’m trying to keep objective facts separate from speculation. I’m here to read both, of course, as long as I can tell the difference.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Santos81, Wow, interesting. Yea.. that definitely seems to rule out the Tesla as a cause. That couples story might not be that odd too.. it looks like they're both actors and have been in several movies. It's interesting that they didn't see anything odd down there too, since 111 had been hearing strange noises for around 30 minutes at that point.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Santos - does this cover all channels? How long are these kept, and what kind of cost are we talking about? Is it full resolution? Does it obviate the need for an in-person guard?

I’m aware that this is possible, but as you said, not entirely common. Regardless, I can’t imagine a modern system with the storage on site but separate from the monitor.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Js5180, The modern ones are actually the opposite.. they're more likely to have a monitor that isn't near the actual storage. Storage in AWS is crazy cheap these days too.. as long as you're only storing around a week of data, you can store a lot up there without paying much. Storing a TB up there is only around $25 a month, and that'll get you pretty far.

I'm used to working on systems for much larger companies really, but a modern system could look something like this. Although I don't think the server has to be an NVR, it could just be a regular computer too. But yea.. even the CMS doesn't actually have to be next to the monitor up front.. or to the storage on the backend. Usually all of this stuff though is stored in a locked network closet somewhere.. sometimes with the HVAC systems. Could be up front, who knows.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

IEGeezer,
Another great translation. Sorry I didnt get back in time to help.
Te invito a comer pulpo y chocos a la grilla y tomar unas cervezas aqui en Canarias. 🐙 cheers

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Truly a quick and dirty. Please forgive any errors.)


Thanks for the incredible effort... wish I could give you a handful of 'stars'.

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (boo1)

Where is the major structural work?

"#2320 - Garage/Entrance/Deck Project for 4.4 Million" listed on page 3 of the executive summary.

Page 47 "structural repairs for garage and pool underside, and planter removal/waterproofing"

I'm sorry, but the "Planning For The Inevitable" (trademarked!) at the top of the report made me laugh/cringe when I read it. They might want to come up with a new catch phrase.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Looks like they were taking this seriously...

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

-Dik

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

It appears that this has been a wake-up call for the Miami area...

Miami Courthouse To Undergo Urgent Repairs After Inspection Prompted By Condo Collapse

An engineer’s report recommended floors 16 and above at the Miami-Dade County Courthouse be closed to staff.


https://www.huffpost.com/entry/miami-dade-county-c...

John R. Baker, P.E. (ret)
EX-'Product Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Couple other interesting items of note in the Reserve Study report:
It states the security surveillance system is from 2017 but still recommended replacement due to advancing technology, and inadequate resolution.

It confirms the fire alarm system has 27 flow sensors, which should have triggered the alarm when flow was sensed in the sprinkler system. Question remains why the F/A didn't activate when sprinkler lines broke in the garage. Speculation here, that these devices either weren't working or were deactivated to prevent false alarms.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Yes. The fire pumps should have activated when the system lost pressure through the broken lines. The sensors were most likely not flow sensors, but low pressure sensors. Flow sensors might not trigger on a slow leak that might even drain the system after awhile. Pressure sensors don't distinguish between pressure lost due to a sprinkler activation by fire, or due to a broken feed line. Low pressure by any cause activates the alarms and turns on the fire pumps (if there were pumps required in that system, probably so for that height). It seems the fire system should have activated to flood any line breaks, if not from pumps, just by the city water pressure alone.

Kind of points to feed water break at supply source, or the entire fire system was deactivated, not just the alarms.

BTW somebody commented above about confusing the word for buckling in es, "Pendeo" is not the same as what you were probably thinking, "pendejo".

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Here is the account of security guard Shamoka Furman on a GoFundMe page set up by Raysa Rodriguez. I have two questions about it though:
1) Wouldn't it be a fire code violation for the lobby doors to not have fail safes that would allow them to open during a power loss?
2) Since the lobby did not have a door to the stairwell, how did Shamoka enter the stairwell to help Maria Monteagudo escape through the garage?

"At approx 1:30am Shamoka heard and felt what she thought was an earthquake. Then the power went out. She called 911. When residents began to call down to the desk, Shamoka told them to "get out of the building immediately". Since the power was out, the front doors of CTS wouldn't open. Shamoka had to crawl through the valet key window. Once she saw there were residents trapped inside she crawled back through. This all happened in a matter of seconds. She grabbed an older resident, worked her way through the collapsed parking garage crawling through water, debris, over crushed cars and finally carrying the resident over a wall and safely out to Collins Ave. She made her way back in to the building and helped an entire family escape this time. She was badly injured in the process. She is covered with bruises from head to toe and may have a cracked rib. She is going to the hospital today. By the time first responders arrived, she was physically ill and hunched over on the street. Shamoka is physically injured and severely traumatized. She is a survivor and a hero. Unfortunately, her only posession in life was the car her deceased mother gave her that was in the visitors parking next to the pool area. As many of you have seen, the remaining portion of the building has been demolished"

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (3IEGeezer (Industrial)10 Jul 21 06:17)

Please forgive any errors.
Thank you, Thank you, Thank you, This video say with much clearer explanations and much more authority, what I would like to say about this design style.

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (1503-44 (Petroleum))

The fire pumps should have activated when the system lost pressure through the broken lines. The sensors were most likely not flow sensors, but low pressure sensors. Flow sensors might not trigger on a slow leak that might even drain the system after awhile. Pressure sensors don't distinguish between pressure lost due to a sprinkler activation by fire, or due to a broken feed line. Low pressure by any cause activates the alarms and turns on the fire pumps (if there were pumps required in that system, probably so for that height). It seems the fire system should have activated to flood any line breaks, if not from pumps, just by the city water pressure alone.

Kind of points to feed water break at supply source, or the entire fire system was deactivated, not just the alarms.

There are 24 flow sensors in the original plans (image, before the penthouse) with none in the basement. The alarm announcement did eventually sound, according to survivors.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (1503-44 (Petroleum) 10 Jul 21 11:23 IEGeezer, Another great translation. Sorry I didnt get back in time to help. Te invito a comer pulpo y chocos a la grilla y tomar unas cervezas aqui en Canarias.)


Thanks. I've never been there, maybe some day. By the way, do you speak Silbo, or rather can you whistle it?

Quote (dik (Structural) 10 Jul 21 12:33 Quote (Truly a quick and dirty. Please forgive any errors.) Thanks for the incredible effort... wish I could give you a handful of 'stars'.)


You're very welcome.

Quote (1503-44 (Petroleum) 10 Jul 21 15:43 BTW somebody commented above about confusing the word for buckling in es, "Pendeo" is not the same as what you were probably thinking, "pendejo".)


Buckling is not Pendeo. It is Pandeo, so no resemblance to (bleep).

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

At the risk of further exposing my ignorance, I have not seen any discussion on why the elevator shaft and equipment room above the 12 floor roof, are skinny beam and column with block in fill, and not a continuous shear wall to top of elevator equipment room and tied to the 12 floor shear wall and structural roof slab.

And then it gets worse with 2nd version of PH addition, with the shaft extension from the original penthouse addition design.

Seems odd to me that Boot leg penthouse has no shear wall reinforcement, and thinned slab roof kinda floating on top with the elevator shaft.

Perhaps the experts might want to discuss this, or after reading all posts, I missed it, please forgive me.

Also it appears to me that the original plan was that Stair tower adjoining elevator shaft was also supposed to be part of RC shear wall, yet it appears to be block fill between columns and beams.



RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (julootamu (Mechanical))

Other than that I agree floors should have had beams but since AC ducts are needed in a dropped ceiling unsure if beams would have added to the height of each floor.

The ductwork seems to be in dropped ceilings away from the outside walls. See timestamp 1:50 in the tour of 611.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Having HVAC experience and looking at duct design, I don't see why that duct design would effect beams at perimeter and in hallway walls. Duct system is very hotel like where you are not supplying air to outside wall, and then returning air to air handler at interior of space.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Or beams in between units

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (pellucider)

There are 24 flow sensors in the original plans (image, before the penthouse) with none in the basement. The alarm announcement did eventually sound, according to survivors.

That's unfortunate the developer decided a fire in the garage wasn't worth waking everyone up for.

Since they sensors were only on the living space floors, it would indicate there were no collapses on the upper floors as have been suspected since a break in the fire lines up there would have triggered the alarm. And we know from the unit 711 Ring video the only sounds were that of drywall dust and rebar snapping - no fire alarm or strobe lights - until after the video was interrupted due to the full-on collapse.

Quote (CE3527)

It states the security surveillance system is from 2017 but still recommended replacement due to advancing technology, and inadequate resolution.

That makes a lot more sense. The CCTV flatscreen in the lobby was showing color camera images and if the security system really was 20 years old, it would be highly unlikely to be using color cameras.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

I am referring to each Condo's split residential looking HVAC systems. I am not talking about the Big Central Building Unit. It does not appear they were taking in any outside make up air for each condo unit, much the same as a typical old school residential home.

They are trying to supply air from near the air handler with short duct runs, in a turn down soffit, with sufficient velocity or throw to reach the outside wall so that the supply air circulates from outside wall to interior return plenum at air handler. So no duct supply or return runs in much of the living space due to low ceiling heights

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

2
The building had no beams because it is a 2-way flat plate design. It was not a mistake as eluded to in the video. This design and construction method is very popular in the US because it simplifies the formwork, uses less concrete, and therefor is faster and cheaper. I’d be willing to bet the new condo next door is built with 2-way flat plate construction, although it’s probably post-tensioned with better connections.
With that said, the governing failure mechanism is punching shear, which is not a ductile failure mode…it happens suddenly. Beams, drop panels, and shear walls would have helped. There are many ways this building could have been better, stronger, more redundant. But developers want the cheapest building allowed by code. Contractors want the easiest building method. Architects love the ceiling height and views created by this method too. The end user, whom the building is supposed to protect, is not involved in the building process. So what incentive is there for an engineer to design something better if it costs more and is more difficult to build?
People assume that if it meets code then it’s safe.
But life safety is only one goal of the code committee’s who write the code and it is balanced with cost of construction. Concrete has to stay competitive with steel and vice versa. Post-tension has to be competitive with steel and RC concrete,etc. There appears to be a false presumption by the public that buildings are over-designed and redundant, but that’s not really the case. In reality they are rarely, if ever, tested to design loads and can generally sit there half empty with poor maintenance for a long time.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

(OP)

Quote (Awestruc (Structural)10 Jul 21 17:47)

and therefor is faster and cheaper
Ture, but sad. 105 or so lives lost. Probably about $300M in liability. (Yes the concrete was "soft", Yes the re-bar was under-nourished, still)

SF Charlie
Eng-Tips.com Forum Policies

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Awestruc, thanks for your response. What I was leading into was residents reporting the building was shaking, perhaps when they drove sheet piles within 10 feet of garage wall. The movement could have been floor slab deflections, beam deflections or column movements. Point being, there without sufficient lateral bracing and rigid enough floors, it appears this is over time loosening up what little reinforcement there is at flat slab interface with columns. Thus time and cycles as mentioned in forum is weakening structure. With sufficient minimum lateral support and reasonable deflection it does not seem building should be moving?

The penthouse, stair tower and elevator shaft don’t appear to have reinforcement in CMU in fill walls. I would think sway from wind or construction next door, or 3.9 bomb effect would cause a more dynamic input into structure than wind loads against apparent sufficient shear resistance from East?

Hope this helps explain my train of thought.

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (Great post!

Report
SFCharlie (Computer)(OP)10 Jul 21 17:58
Quote (Awestruc (Structural)10 Jul 21 17:47)
and therefor is faster and cheaper
Probably about $300M in liability.)

How many units were there? It looks like the last ones sold went for about $700K.
What was the square foot each floor?
Thanks,

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Mechanical equipment located at height more than 100 feet shall comply with FMC 301.15,
have a site-specific design (signed and sealed) by a Florida Professional Engineer, indicating
the location of mechanical equipment, the required design pressures and the installation
method.

Page 19

RE: Miami Beach, Champlain Towers South apartment building collapse, Part 04

Quote (SFCharlie)


SFCharlie (Computer)
(OP)
10 Jul 21 17:31
Please allow me to move the discussion to Miami Beach, Champlain Towers South apartment building collapse, Part 05,
Thank-you.
Someone Please close this post to new postings, or message me how to do this, Thanks.

Quote (SFCharlie)


SFCharlie (Computer)
(OP)
10 Jul 21 17:58

Quote (Awestruc (Structural)10 Jul 21 17:47)
and therefor is faster and cheaper

Ture, but sad. 105 or so lives lost. Probably about $300M in liability. (Yes the concrete was "soft", Yes the re-bar was under-nourished, still)

David and 1503-44; Resistance is futile. You will be ignored!

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

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