51 unaccounted for after deadly high-rise collapse in Florida

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Red Squirrel

No Lifer
May 24, 2003
70,454
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www.anyf.ca
Wonder if some of the water pooling in the parking garage also started to seep into the ground below and slowly eroded it. Eventually the columns shifted down enough to cause the floors to start separating and finally it all gave way. Also the way the floors are fastened to the columns is very suspect. Should there not be metal I beams between each column? It looks like they opted for post tensioning instead which is very tricky to get right especially if you're doing a grid. I'm not an engineer but not seeing metal I beams does not sit well with me. The reports of every window leaking could have been a clue there was lot of movement to the building too.

Those columns also seem kinda small to consider the number of floors.

Random pic I found of one:

44787569-9734511-Structural_damage_can_be_seen_at_Champlain_Towers_East_adjacent_-m-25_1624917225558.jpg


Going to guess it's maybe a foot and a half wide. Though I don't think the size is the culprit, the way the floors broke right through seems to indicate the floors themselves did not sit that solidly on the collumns. Reminds me of people who build decks and use nice beefy 6x6 posts, but then bolt the beams on the side. You're relying on a couple dozen bolts to hold the weight of the entire deck instead of relying on the actual supports. In this case, the rebar or post tensioning cables.

I'm no engineer so maybe I'm off here but that's just my observation.
 

ISAslot

Platinum Member
Jan 22, 2001
2,890
108
106
After watching many videos and seeing how things are constructed, I still don't see the 'smoking gun'. I'm highly suspicious of the deck and planter area in front of the building opposite the garage entrance ramp. At that location the floor concrete pour transitions down in several places. Some of these transitions even look uneven, probably from poor form work, but if the form work was bad, how was the steel work? Plus the large planters were added, and the pool deck had sand and pavers. Was this too much weight for a 9.5" slab at these spans? Did a planter clog and fill with water? Did some planters leak badly corroding the concrete severely where the damage was hidden?
 

skyking

Lifer
Nov 21, 2001
22,746
5,904
146
Wonder if some of the water pooling in the parking garage also started to seep into the ground below and slowly eroded it. Eventually the columns shifted down enough to cause the floors to start separating and finally it all gave way. Also the way the floors are fastened to the columns is very suspect. Should there not be metal I beams between each column? It looks like they opted for post tensioning instead which is very tricky to get right especially if you're doing a grid. I'm not an engineer but not seeing metal I beams does not sit well with me. The reports of every window leaking could have been a clue there was lot of movement to the building too.

Those columns also seem kinda small to consider the number of floors.

Random pic I found of one:

44787569-9734511-Structural_damage_can_be_seen_at_Champlain_Towers_East_adjacent_-m-25_1624917225558.jpg


Going to guess it's maybe a foot and a half wide. Though I don't think the size is the culprit, the way the floors broke right through seems to indicate the floors themselves did not sit that solidly on the collumns. Reminds me of people who build decks and use nice beefy 6x6 posts, but then bolt the beams on the side. You're relying on a couple dozen bolts to hold the weight of the entire deck instead of relying on the actual supports. In this case, the rebar or post tensioning cables.

I'm no engineer so maybe I'm off here but that's just my observation.
you have it backwards, RS.
The columns are on augur cast piling, drilled to a solid strata far below the fill area that the building is on. They did not fail in the manner that you think.
The columns *MUST* be supported laterally every X number of feet, or they will fail in a buckling action. The slab that was poured at the lowest level, the one that is on the earth, was critical part of that lateral support and when that slab settled enough, the columns are now doomed.
The site was on a fill. Fills settle over time unless constructed with great care and from good materials.
Those leaks certainly added to the final disposition, but the very nature of the site was also a problem.
When doing construction on bad materials like that, we tend to place that bottom slab on grade beams. Those are massive reinforced concrete beams that are poured on top of their own set of dedicated augur cast piling, and then the rebar tails poured into the tops of those beams are incorporated into the thick heavily reinforced slab.
The beams are close together and the slab does not rely on the direct support of the ground it is poured over.
 
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gorobei

Diamond Member
Jan 7, 2007
3,988
1,487
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i came across this channel a few weeks ago. they cover the collapse and the engineering issues over a dozen videos or so. they pulled the filed plans and did a structural engineering review. he seems to have zeroed in on a key issue with the 'as built'. (tldr: some column/sections were at 100% load, live load wasnt addressed, beams under planters were removed.) beware highly technical.
 

pmv

Lifer
May 30, 2008
15,142
10,033
136
Another summary of the issue - can't see if it's been posted already yet. Sounds like it was "multi-causal", so presumably determining "responsibility" is going to be a huge task? Agrees with the video above, in that there were major structural problems with it as built.

Seems monumentally-absurd that so much corner-cutting happened because of a desire to fit more cars into the underground car-park, as if parking-spaces are more important than lives.

 

Torn Mind

Lifer
Nov 25, 2012
12,065
2,768
136
^^^ Do you really want Florida people scattered all over the county?

Really?


OK, maybe Texas will take them.
Unfair characterization. Many people in Florida are transplants from elsewhere. Many of the victims in these particular apartments paid their dues in life in NY.

Brian Laundrie started his life in New Jersey.