Miami Beach, Champlain Towers South apartment building collapse, Part 02 151

[dik]

thread815-484587


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

-Dik

 

[bradw1128]

More on the concerns that led to the halt of searching overnight:

https://www.miamiherald.com/news/local/community/miami-dade/miami-beach/article252490903.html

Miami-Dade Fire Chief Alan Cominsky said engineers raised several concerns with structural issues of the building. Mainly, they documented 6 to 12 inches of movement in a large column that may damage a super column in the garage. There has also been “slight movement” in a concrete slab on the south side of the building that “could cause additional failure of the building.”

He said there has also been movement in the debris pile.

Florida Gov. Ron DeSantis, speaking at Thursday’s briefing, said “obviously last night there were issues with the remaining structure” of the Champlain Towers South Condo, but added that state engineers were helping Miami-Dade Fire Rescue get “different options on how to handle this.”

“Obviously we believe that continuing searching is something that’s very important,” DeSantis said.

Bradley Wilder, P.E.
Construction P.E. (KY), MBA
Bridge Rehab, Coatings, Structural Repair

 

[ProEpro]

"Possible Failure Point Emerges in Miami-Area Building Collapse"

https://www-nytimes-com.cdn.ampproject.org/v/s/

http://www.nytimes.com/2021/06/27/u...27/us/miami-building-investigation-clues.html

NY Times article agrees with the discussion here. Has some good graphics.

"The National Institute of Standards and Technology, a federal agency, was sending scientists and engineers to do a preliminary review, hoping to identify and preserve materials that might help understand the collapse. Officials said they expected a number of local, state and federal agencies also to be involved in the inquiry, though it was not clear which agency would lead the effort"

I hope that becomes clear very soon.

 

[TheGreenLama]

And to make matters worse a tropical storm is expected in the area by Tues.

 

[spinspecdrt]

I like this theory. There is also a 1' step in the slab in this area.

 

[Roga50]

1) Are there any safeguards (i.e. laws) in place to prevent some condo owners from stonewalling paying for repairs to the common building until after they sell/flip their individual units? If not I can imagine it would be quite a common practice. Simply sell, move to another building, wait until large maintenance assessments are projected, sell and start the process again. There was mention earlier of a recent buyer of a unit in this building who knew nothing of the 2018 report. Did this buyer also know nothing of the impending maintenance assessment, or is this more of a buyer not doing the proper homework?

In the WSVN "Help me Howard" link I posted above, he does kind of talk about that. If the homeowner refuses to pay, the condo board can foreclose on their unit. But that probably does take considerable time. And then, of course, the unit would have to be sold to someone else willing to pay the assessment.

(for those not from Florida, "Howard" in the video was the head of the Broward County public defender office for many years. Broward County is just north of the location of the collapse.

 

[Retiredat46]

What are the chances the Florida officials will decide to bring down the standing portion of the building with a controlled demolition rather than take a chance that it will come down on its own during the approaching tropical storm? It's undoubtedly compromised, and reducing the risk of damage to nearby buildings may outweigh other considerations.

I doubt there's enough time to shore up the building, but there may be time to arrange a controlled demolition. It's going to be a tough call to cancel the paused search and rescue effort, though.

 

[bradw1128]

It's going to be a tough call to cancel the paused search and rescue effort, though.

Maybe someone who has worked on an urban search and rescue task force could speak to this? From what I can gather, these teams are equipped to be deployed for around 10 days. At some point, the operation ceases to be rescue-focused and becomes recovery-focused. That's got to be a hard call for someone to make but it will happen eventually. When it does, the calculus changes a lot in exposing anyone on site to the risk of further collapse.

Bradley Wilder, P.E.
Construction P.E. (KY), MBA
Bridge Rehab, Coatings, Structural Repair

 

[LittleInch]

My reasoning is simply to try and put together the eye witness stories who all talk about the pool areas seeming to subside with what other evidence we have.

Now maybe part of the building went first and then the pool deck area and then the building or maybe the other way around. But I just thought it is at least worth considering as it seems to be a weak point and could be the start point of the whole collapse. There is also talk about the impact of the building work on the condo to the south and the effect on the whole thing of that sheet pile wall which went in a few years ago only 5m or so the south of the exterior wall.



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[spsalso]

If they do decide to bring the building down soon, I hope and expect them to gather evidence first. If necessary, one of those robot thingys that are all the rage could get sent in. Well, not maybe into the debris pile, but into parts of the garage that aren't fully collapsed.

On a slightly different note, it's been a week since this happened, and I haven't noticed the name of the company that built this. Did I miss it?


spsalso

 

[dold]

What are the chances the Florida officials will decide to bring down the standing portion of the building with a controlled demolition .

No idea, but I wonder if they would consider bringing the building down to the west and into the street, so as to preserve the working area to the east? The only thing to the west is Collins ave and a park/tennis courts.

 

[Retiredat46]

Here's the info from:

https://en.wikipedia.org/wiki/Surfside_condominium_building_collapse

"William M. Friedman & Associates Architects, Inc., was the architect for the project's 1979 contract drawings.[27][28] Breiterman Jurado & Associates, consulting engineers, were responsible for engineering aspects and the 1979 contract drawings, with Brieterman and associates covering structural items and Jurado and associates covering electrical and mechanical.[27][28] Nattel Construction, Inc., of Miami Beach was the general contractor for the construction of all three buildings.[7]"

According to:

https://www.corporationwiki.com/Florida/Miami-Beach/nattel-construction-inc-3902977.aspx

"Nattel Construction, Inc. filed as a Domestic for Profit Corporation in the State of Florida and is NO LONGER ACTIVE. This corporate entity was filed approximately forty-two years ago on Tuesday, June 19, 1979 , according to public records filed with Florida Department of State."


Bringing the building down in the street might seriously damage some critical underground infrastructure.

 

[ChiefInspectorJ]

Here is an excellent video of the collapse area. You can see the punch thru of the columns .It looks the Patio/slab garage roof hit the building columns.

https://www.foxnews.com/us/miami-condo-collapse-survivor-miracle-escaped

Those buildings survived Hurricane Andrew. But couldn't survive foundation and torsion problems. Soft Story.

 

[SFCharlie]

Many of us agree that the "surveillance video" starts after the collapse was initiated.
I hope that the grand jury will subpoena the original video.
Also, I hope they will subpoena any video from all surrounding buildings.
The literature from Champlain Tower South state that they have video surveillance, this should have survived (I hope.)


SF Charlie
Eng-Tips.com Forum Policies

 

[Retiredat46]

I think the rubble at the end of the ramp to the underground parking area may be critical in determining the trigger event. It's probably going to be stay pretty much where it is now regardless of how the standing part comes down, and it may be possible to determine where it came from.

 

[ChiefInspectorJ]

I have found with 30 years of inspection experience that the ACI minimum concrete cover is severely deficient. And on top of the space requirement there is a tolerance to that dimension allowed.In field tolerance on any thing are lucky to be 3/4" especially since concrete is not smooth and some aggregates are at the surface not perfectly flat like a crystal.

 

[AtomixPro]

Extensive 4K aerial drone footage from various angles. Set the player settings to 4K. You can zoom in quite well to areas of interest.

https://www.youtube.com/watch?v=GyrvMi-4QE4&t=115s

 

[AtomixPro]

From the drone footage I linked, you can see a large part of the 111 planters still fairly intact.

It's interesting how large parts of the deck structure remained elevated despite the collapse. It almost seems as though the west pool deck and upper level parking area collapsed further than the deck directly beneath the collapsed building.

We know that Sara Nir saw the upper level south parking collapse prior to the full collapse. The Stratton account as described by her husband was of the "pool caving in". Clearly she didn't mean the pool itself, but this area west of the pool is more suited to the description. She had a good view of the pool and upper parking, not so much the 111 planters.

For higher resolution views and different perspective, see the video itself.

 

[TheGreenLama]

It's become "relatively" clear--based on witness testimony--that the portion of the patio slab, which also served as parking and was visible from the lobby, collapsed prior to the main building collapse. It's still unclear if this area came down prior to other sections of the patio deck, or was brought down by adjacent spans collapsing. But again, it wasn't brought down by the building.

Elsewhere in the thread it has been suggested that the unzipping of the bottom rebar seen here is not unimaginable in high impact collapse events. But here, for this section of slab, we do not have a high impact collapse event--unless you consider a span in the the adjacent bay failing and falling 10 ft. To me this suggests that something is seriously wrong with the ability of the bottom reinforcement to develop (causes have been discussed elsewhere). I would posit that there may exist these rebar development deficiencies building-wide, as similar unzipping instances can be seen in other photos.

 

[Roga50]

Re video from security cameras on the property: the plans show that the security office seems to be next to the mail room, next to the elevators in the part of the building that is still standing. So even if all video recording is on-prem, the servers would most likely be in that room and have survived. There also seems to be slight mention [I could be wrong--forget where I saw it in the plans] of a "telemetry computer" in the office between the trash/electrical room and the front desk (also in an area still standing)? Of course, that was back in the 80's so no idea what that really was or what it would capture. At a previous employer of mine down here, I worked in a building from the same era and our telemetry computer was mostly related to the HVAC system and smoke fans/vents/fire alarm system.

 

[AtomixPro]

Hopefully someone with jurisdiction has the foresight to check for the CCTV system before they demolish or further disturb the still standing building.