Miami Beach, Champlain Towers South apartment building collapse, Part 11 54

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04
Miami Beach, Champlain Towers South apartment building collapse, Part 05
Miami Beach, Champlain Towers South apartment building collapse, Part 06
Miami Beach, Champlain Towers South apartment building collapse, Part 07
Miami Beach, Champlain Towers South apartment building collapse, Part 08
Miami Beach, Champlain Towers South apartment building collapse, Part 09
Miami Beach, Champlain Towers South apartment building collapse, Part 10


SF Charlie
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[12345abc6ttyui67]

MarkBob2, I'm sorry I have not read the full text of your post, but looking at the photos I just can't make my eyes see any of the things you seem to see. As best I can tell all you are pointing at are smashed up bits of concrete and rebar. I really can't fathom how you are making anything different out of these photos.

 

[MarkBoB2]

SFCharlie, the full video is titled "Recovery Efforts Continue at Surfside Collapse Site", and can be found at

https://www.youtube.com/watch?v=jI6Up5Nv70c.

The scene from which this photo was taken occurs at 4:45 into the 5:02 long video.

 

[SFCharlie]

SFCharlie, the full video is titled "Recovery Efforts Continue at Surfside Collapse Site"

Thank you very much!


SF Charlie
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[Red Corona]

Is that cable? I just thought it was the thin rebar (from slab bottom or something) and it was pale because it was dusty. But it does kind of look like cable.

I'm not convinced by the image interpretation though and I still think it's very unlikely that something like that fell right outside 111's window without that being in 111's story. Or that an operative was on the pool deck trying to bring an AC (or anything else) down after midnight, again with 111 mentioning it.

 

[gonefishing2]

Markbob2, I will only comment on your item 8, as I have lots of HVAC hands-on experience that conflicts with your number 8 narrative. I don't know where you got your information for number 8, but it is so far off, I have to furnish correct information.

Most of the roof AC units you are referring to are residential units, which would contain either R22 with mineral oil, or R410a with synthetic oil. Neither of those refrigerants or oils produces the 'weird' smells that would be noticed by anybody. What smell there is dissipates very quickly and size of hole determines how fast the refrigerant vents into the environment. So cross that one off your list.

My current Rheem 3 ton residential HVAC units have about 19 lbs of refrigerant in each of them. One is more than the other due to longer line set. I know this because I weighted the refrigerant in when I had to repair an outdoor unit leak. The manufacture label contains the amount of refrigerant pre-charge in the outdoor unit, and tells you how much refrigerant to add for each foot of line set beyond 15 feet (depending on line set size). So 3 lbs or a normal residential home system is way off. Think about how long the line set is for first floor air handler with a roof condenser. The other problem is that over the years depending on manufacture or compressor type or size of coils, the amount of refrigerant can vary a lot. My systems are 12 years old, and newer ones take less refrigerant than my 410a systems. Again your assumption is so far off, I have to offer correct information.

Bottom line, Throw out your number 8 assumption all together. It is wrong and unsupported by real world data.

I will be honest, all I did was scan your long list of statements, and this one caught my eye because I know it is 100% wrong and can validate that it is wrong, so I felt compelled to correct your assumption.

Not trying to be critical, but it sure would help credibility if things like your number 8 were actually even in the ballpark of being realistic without easily seeing it is way off. I only speak for number 8, since I am expert on this subject.

Edit: BTW, you found a winch. The roof hoist would not have used a winch. It had to be a hoist rated system for overhead lifting. Winches are for horizontal pulls like pulling a car up onto a trailer or pulling a 4WD out of the mud.

Edit2: HVAC guys use cordless impact drivers, drills or hand tools to loosen and tighten nuts, bolts and screws. Not dragging a compressor around to use air tools.

Edit3: Most of oil is in outdoor unit on roof, and that is where the higher percentage of refrigerant would be. Once a line shear leak developed on roof, the refrigerant would escape to atmosphere quickly.

 

[Debirlfan]

If you want to talk about suspicious orange cones, I'd be more interested in talking about the one seen on the police body cam, that was located right beside the edge where the slab broke off in the parking area. Was it there because there was already some damage in that area?

 

[MaudSTL]

Sincere thanks to all who have described various possibilities related to the building’s load redistribution. It seems so impressive that the building adapted and adapted for over two hours in order to keep its balance, almost managed to find it, and then lost it after all.

Am I correct in thinking that the first collapse at 1:10 was the straw that finally broke the deck’s back? Or could that simply be coincidental rather than causal? I understand we are speculating. My interest is in understanding the various ways we can understand the sequence of events.

 

[Sym P. le]

... for this 2.5' height of column at the step beam column joint, the contractor may have used 4000 psi concrete instead of 6000psi for columns. As there were no requirements for puddling back in ACI 318-77.

I refer to dwg "S5 of 14" from R1 of the Surfside document package (or page 31 of the PDF) which I believe is the revision closest to construction.

Along grid 9.1, a slab step of 1'-6" is specified, altered from other revisions using 2'-6", and would effect columns I, K, and M, where column L would only see a 7" step. This step revision also places the pool deck elevation at +11'-10", at par with the above ground parking as opposed to the alternative arrangement where the parking was at an intermediate elevation between the building slab and the pool deck slab.

In your video, I do not recall you mentioning the parking adjacent to the thirty foot span between columns under the pool deck nor the planters separating the pool deck from the parking, both of which impinge on the weakest area of deck slab. Can you update your model to account for this extra load?

 

[Vance Wiley]

For those Mechanicals on this thread - some credit, I think.
- - - - - - - - - - - - - - - -
1875 Ward's Castle - William Ward, a mechanical engineer living in Port Chester, New York, chose to build an all concrete house. It was the first reinforced concrete structure to be built in the United States. When it was completed, neighbors expecting it's imminent collapse called it "Ward's Folly", but after years of little wear and much comfort, it earned a new, well-deserved appellation, "Ward's Castle".

Source:

http://www.dupontcastle.com/castles/wards.htm

 

[Optical98]

Debirlfan

I believe that cone was used to reserve certain parking spaces on the upper level.

 

[gonefishing2]

Ward's Concrete Castle would have been great in summer before Air Conditioning, but I am not so sure it would have been very comfortable in winter?

 

[MaudSTL]

Tangential but interesting, from the Miami-Herald. Miami losing another chief resilience officer. What’s left of the climate change department?

 

[Debirlfan]

I believe that cone was used to reserve certain parking spaces on the upper level.

Entirely possible. Given where it was located, it did seem suspicious.

 

[zebraso]

Not trying to be critical

I think I can be a little more critical. A 3 ton condenser unit weighs maybe 150 lbs shipped with a charge in it. I don't know what the terminal velocity would be but they would catch some air given the grid and radiator fins. If a single condensor hitting the ground (or the deck) was even felt as a vibration in the structure I would be surprised. I am not saying these things would even implode or disintegrate when hitting the ground from that height. You could probably rebuild it. I mean a 35 inch direct view tv set from 1990 weighs twice as much.

Edit: about 22.6 kJ at impact at most for a 3 "ton" unit weighing 150 lbs. At 93 km/h with no wind resistance. Someone will correct me if I'm wrong. Crumpling would absorb some of that energy I assume. Seriously though no one would rebuild it because the coil would be toast, but you might be able to salvage the compressor!

Edit: one to many kilos (k double transposed)

 

[MaudSTL]

Contemporary drone shots. Surfside is opening up the west lane of Collins. The foundation does not appear to be braced.

https://www.local10.com/news/local/...fside-collapse-site-to-ease-traffic-concerns/

 

[gonefishing2]

Edit: Perhaps a 3 lb refrigerant system in flight?

 

[gonefishing2]

It seems to me that there should be a larger right of way along Collins Avenue, such that a private owners building’s foundation wall did not affect the public roads?

Or perhaps the public road should include lateral support for roadway?

Or there should be adequate setback from property lines before digging below grade level?

It seems a building failure should not compromise public roadways.

 

[zebraso]

3 lb

As a prop? yeah. ha. They got that to look pretty real. David Letterman used to do a gag where he dropped stuff off of the Ed Sullivan (I think) theater. It was never very impressive (mostly anti-climatic). It wasn't 13 stories either AFAIR. I wouldn't doubt he actually dropped an ac unit. Of course they took all the proper safeguards. I am sure he dropped things that weighed at least 150 lbs. Generally most things don't disintegrate into bits and pieces unless they are really brittle. AC unit? nah.

 

[raymiepo]

noticed in the vid local10 news report (link that MaudSTL provided [thanks, MaudSTL])small and large pump dewatering (I'm supposing)trucks.
I'd post the picks I had screenshot from the report vid, as a convenience, but don't know the copyright protocol for the forum. sorry. easy enough to view the vid.
of course, don't know exactly when the drone vid was taken. could have been stock footage, maybe.
but I noted the location of the trucks????
in a case, like this, would they haul and dump the water?
or consider the use of the well, which was possibly never permitted?
also, wondering the ratio of sea water to fresh?

 

[Spartan5]

Re: Letterman. The building was 7 stories. Amongst other things, there’s a 250 lb safe coming off it at the 2-minute mark.

https://m.youtube.com/watch?v=nAUknFYFla0