Miami Beach, Champlain Towers South apartment building collapse, Part 06 131

[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

SF Charlie
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[CE3527]

Optical98 - I wondered about the stories of people going from the upper floors to the basement (instead of via the lobby) as well. A review of the floor plans shows that the stairwell didn't have an inside lobby level exit. The lobby level exit was instead on the side of the collapsed pool deck. The exit door is blocked by debris in the photos. It seems really silly that if you park your car and want to go straight to the lobby you have go up, go outside on the pool deck, and then back in (or take the elevator). Apparently that's the way it was. While the stairs remained open, it seems that the people "trapped" on the balconies were the ones that feared going through the garage. One of them mentioned fear of electrocution in the standing water, which would have been a legit concern.

 

[jbourne8]

The 911 calls from the survivors were released btw -

https://www.youtube.com/watch?v=-V82BZuV-m4

 

[CE3527]

Does anybody have any theories on this concrete slab in the post-debris removal photo? It appears to be fairly in tact in areas where it's exposed. I thought initially this was the garage slab on grade and they just removed the rest of the garage slab on grade around it which became filled with standing water. But I don't think there's any reason for them to remove the garage slab on grade, or that place becomes a mudhole plus I haven't seen it removed in any pictures. Then I thought maybe it's the pool deck from above, but A) it doesn't have pavers on it and B) this is the exact area in the Tik Tok video where it seems to show concrete chunks to have fallen, so how would this be in one neat piece?

Maybe the answer is obvious, but it's escaping me.

 

[Optical98]

I haven't figured out how to reply to people on here yet, Odds n Ends --

Someone asked where the Storage Areas were at:

Link


Marked area on Ramp, they drew(sprayed) a red rectangle and placed cones about it.

Link

This is a tough read, it's from an article regarding the Mother and Daughter (Unit 904) that fell but have survived thankfully (Prayers for a speedy recovery for both of them)!
I'm posting it because in their accounting of events, they did not drop all the way down at once, there were seconds between the floors dropping... 9th dropped to 8th, paused briefly, then down to the 3rd floor.

Link

 

[Tropmet]

Optical98, the most important thing the photos you found show is that at some point the entire ceiling of the entry driveway fell down, falling onto a vehicle parked there. This had to happen after residents were able to safely exit out of the front door after the pool deck and part of the valet parking collapsed (the Nirs and the South American celebrity couple). It is unknown whether this occurred at the time of the building collapse or happened after. The ladder is clearly providing 2nd floor access to the building for emergency workers.

If the entryway ceiling collapse happened some time later after the building collapse that may have been an indication that the remaining building was unstable, but that is simply a guess on my part.

The surviving stairwell next to the elevators did not have an exit into the lobby. On the lobby level it only had an exit outside to the pool deck. Images show that there was no way to exit there as the decking collapsed a few feet outside that door (see image below). The other exit door was at the basement level and accounts said there was debris there that one group of residents climbed over to exit from the garage (I am guessing through the gaping hole we have seen at the back of the valet parking). I think I remember reading that group went down to the beach. They could have done so by making their way up onto the remaining pool deck and walking over debris to the exit gate by the pool. I found that surprising but if leaving through the garage it seems there would be no other way. This was the family I believe in an 06 unit, parents and two teenagers, who also rescued an 88 year old making her way down the staircase as they went down. Others said they could not navigate the debris at the bottom of the stairwell in the basement level and went back up to the second or third floor to a balcony out front to be rescued. This I believe was the woman who left a phone message accidentally that was played on the news as she went to other apartments on the floor to find neighbors.

 

[Demented]

https://www.youtube.com/watch?v=VM416Xg-oBQ

Precision guess work based on information provided by those of questionable knowledge

 

[Colostruct]

It does seem to be higher than the other slab areas which I assume are submerged. Is it possible that this is an upper slab that punched through? The slab elevation change, planters and the supporting beam I feel that might have failed first is to the south of this location.

 

[CE3527]

Colostruct - yes, that makes the most sense to me that it's the pool deck slab. they may have just removed the pavers. someone in the tiktok video said "i thought it was an accident". if that slab pulled away from the building as one piece and dropped suddenly to the ground it would have made a huge bang.

 

[Optical98]

CE3527 and Tropmet, thank you for responding! Yes, I knew the Stairwell exited to the pool deck vs the Lobby. What I was trying to determine was if the drive thru had fallen down as there hasn't been much photo evidence but survivors speaking of it falling. Also this verifies what you spoke of Tropmet, regarding the Entryway Ceiling >

Link

 

[1503-44]

CE3527 it also seems less than ideal to be forced to bypass the lobby and direct street level egress and continue down to the underground parking lot in the event of emergencies. How can it be allowed to block the most direct egress route to street level and the supposed safest and fastest means to exit the building during emergencies.

 

[Demented]

Does anyone know at which elevation the piles were driven down at? I cannot find it in any of the drawing files I have. I just noticed the 3'6" depth of them.

Precision guess work based on information provided by those of questionable knowledge

 

[Santos81]

Those figures surprise me. Does that mean that a flat roof equipped with a parapet and scuppers as described would collect and hold a considerable amount of water before it was able to drain through those devices? I am somewhat ignorant on the subject, but I have to assume that the roof would be designed to shift the water to some other means of collection/discharge and would not be designed with the expectation that it would regularly hold up to several inches of accumulated rainfall?

This building used Internal Discharge as primary with only smaller elevated zones using scuppers as primary to discharge to the internal zone below. Overflow Scuppers are for when the rate of rainfall exceeds the flow capacity of the internal system or if a drain becomes blocked.

 

[Demented]

CE3527 it also seems less than ideal to be forced to bypass the lobby and direct street level egress and continue down to the underground parking lot in the event of emergencies. How can it be allowed to block the most direct egress route to street level and the supposed safest and fastest means to exit the building during emergencies.

Because this is Florida

https://i.imgur.com/ce6du4p.jpg

Approved by Palm Beach County Fire Marshall.
Edit: Hell, OSHA even turned a blind eye to this.

A 4 story apartment building now stands where a lake was 2 months ago. They just simply relocated and reshaped the lake. Logic and safety isn't a thing here.

 

[Colostruct]

CE3527

I don't think it's the pool exterior slab. I believe it is an interior slab. If I have the orientation right from the plans, there is a row of columns between the base of the ramp and the exterior of the building and we can see remnants of two of those column in the photo you referenced. I believe the outside of the building and the edge of the planter/pool deck would be further down the photo. (South on the drawings). Unfortunately, I haven't see a great photo of what the beam looked like at that location.

But, I do believe this to be "ground zero" for the collapse of the building (after initial collapse of the pool deck and upper parking areas). My gut feeling is that the column to the right of this "slab" you are pointing out is the one that finally collapsed and brought the building down. That makes sense because the building didn't lean much as it went down.

Edit. Whoops. I meant the column to the left massively failed and initiated the main collapse. This was AFTER the beam at the slab change initially failed and caused the first wave of damage.

 

[Demented]

The generator room would be located there if I am not mistaken.

Precision guess work based on information provided by those of questionable knowledge

 

[1503-44]

OMG!

When I worked at Petrofac in Sharja, UAE we evacuated our 12 story building for an earthquake. Being the first to get the Heck out of there, I ran down the stairs to ground level and found massive doors. They were easy to open at the time, because I was one of only two people to reach the exit that quickly. If there had been any more people there at the bottom of the stairs, we might have been crushed up against them by a crowd, because the doors opened only toward us.

As soon as the all clear had been given and I arrived back at my desk, I found the company's safety violation notice form used by our construction activities group and wrote them up. It took awhile and I had actually left that company by the time, but a year later I was told that they did act on the violation I wrote up and reversed the direction of the doors to open outward, exactly as I had told them. Surprisingly, or not, the practice of outward opening emergency doors is far from universal and they are in fact common in many countries, in the EU and UK included. Inward opening emergency use doors are extremely dangerous.

 

[Santos81]

Does anybody have any theories on this concrete slab in the post-debris removal photo?

Should be the basement slab which is not entirely on grade. There are pits for the storm drainage system below. One of the larger ones is between that slab and the end of the ramp.

To add:

The water level will change with the tide. The TOS elevation was surveyed at -0.27ft NAVD so it’s underwater outside of low tide.

 

[NOLAscience]

You need someone with autism super powers to imagine ways that buildings can collapse.

I disagree with this statement. We (structural engineers) deal with this every day, if we deal with non-routine arrangements, different restrictions, etc. We all imagine the ways that a building would collapse under different combinations of load, damage, etc.

 

[Optical98]

The Generator room location >
Link

 

[1503-44]

Probably not a serious comment there NOLA.
I know this is serious business, but can we see the humor and let it go.... just this once.