This has obviously been the topic of discussion in the engineering/design field with colleagues and many theories are being batted around. One thing that I stumbled on is that if you look at the "sister" building it is the same but different. There is an additional bay in the building that collapsed. What raises red flags is that the additional bay is also where the collapse of the building appeared to have propagated from. That additional bay also includes an additional bay in the plaza deck by the pool.
At the moment this absolutely proves nothing. It is just an observation I made. It is something that I am sure they will be looking at. I don't know what building was designed/built first. If I was part of the investigation it would be high on my list to have a team look at this along with all the other things they will evaluate.
Satellite Photo showing the two buildings:
I haven't figured out the pool...
That satellite pic shows a pool separate from the building. Was there a 2nd one inside? Was it located somewhere other than the ground floor?
In reply to SVreX (Forum Supporter) :
The one in the pic is the pool everyone mentions. There is a parking garage underneath the pool and building.
Is it just me with a tainted bias... but in the above picture the 'North" building looks better maintained, more polished, etc.
The difference in two different sets of owners and condo associations?
SVreX (Forum Supporter) said:
I haven't figured out the pool...
That satellite pic shows a pool separate from the building. Was there a 2nd one inside? Was it located somewhere other than the ground floor?
My interpretation from the beginning of this was that the "pool deck" is the wording that stuck. The pool is relevant but it is the large paved area for residents to congregate around the pool as well as use for circulation.
That entire paved surface should have water management systems incorporated into the layers between it and the parking garage and foundations. That water management is where I think the focus of the engineering report directed the early and current conversation. The pool is likely less relevant.
In reply to Purple Frog (Forum Supporter) :
I think that white roof building in the middle is between the two sister towers and may be a cousin tower.
The two older roof color buildings on each edge of the photo are I think the buildings Dean is discussing.
NOHOME
MegaDork
7/22/21 11:35 a.m.
In reply to Purple Frog (Forum Supporter) :
I had the same thought.
In reply to dean1484 :
Interesting observation. I would think the design would be scalable based on my observation. The structural walls have the floors spanning between to form each apartment bay. The tolerance stackup plus wind load and seismic action could result in the longer overall length structure of the building that failed seeing increased stresses at the structural wall in Picture North from which the fallen and standing building were separated.
STM317
UberDork
7/22/21 11:45 a.m.
Advan046 said:
In reply to Purple Frog (Forum Supporter) :
I think that white roof building in the middle is between the two sister towers and may be a cousin tower.
The two older roof color buildings on each edge of the photo are I think the buildings Dean is discussing.
Even so, the North tower appears to have fresher paint on the trim, the balconies are more uniform, there's cleaner cement on the pool deck, and the chairs on the pool deck are neatly spaced rather than haphazardly placed all around.
Underground parking garage seems like a bad idea all around in that area. I'd thought it was above ground, and now all the comments about flooding and corrosion make a whole lot more horrifying sense.
Interestingly, "AvE" autosuggests "building collapse" on YouTube's search bar.
In reply to Pete. (l33t FS) :
That's a really good, well balanced summary.
More old buildings coming apart in Miami. Could it be something in the air?
Snowdoggie (Forum Supporter) said:
More old buildings coming apart in Miami. Could it be something in the air?
More likely something in the ground. After hearing about the earthquakes in the Caribbean.... a good quake in south Florida... oh boy.
I have watched some other videos from the link above. He is quite good.
aircooled said:
Snowdoggie (Forum Supporter) said:
More old buildings coming apart in Miami. Could it be something in the air?
More likely something in the ground. After hearing about the earthquakes in the Caribbean.... a good quake in south Florida... oh boy.
I have watched some other videos from the link above. He is quite good.
That garage at The Hemispheres looks a lot like Champlain Towers before it fell. This building is even bigger and taller and older than Champlain Towers, not to mention right down the road. Very scary.
I wanted to maybe put a little closure to this. From this article, it looks like multiple things came together to cause this.
The building not being code-compliant when built.
Salt water from the pool deck leaking into the structure corroding the rebar.
Adding significant weight to the plaza/pool deck in the form of concrete planters after the fact that it was not designed for.
Article from NPR here
https://www.npr.org/2024/03/08/1236628075/surfside-florida-champlain-towers-south-condo-collapse-cause#:~:text=Because%20of%20design%20flaws%2C%20investigators,structure%20itself%20before%20the%20collapse.
On a side note, the NIST investigator Mr. Glenn Bell is someone I worked with back in my early days when I was just getting into the field. He is one of the smartest and most skilled Civil Engineers I know. And to top it off he is one of the nicest people. He would take the time to explain things to me when I was just starting out. He did not have to do that. I can not say enough good things about him.
His Bio is here : https://www.nist.gov/people/glenn-r-bell
SV reX
MegaDork
7/9/24 10:16 p.m.
Kinda odd wording there.
"..concrete used in the pool deck and in the columns that supported it was weaker than required by building codes."
I'm not sure what that means. I'm not aware of any codified concrete strength rating that would apply to a building this size. It would all be defined by the engineering.
Drop Mr Bell an Email about it. His email is in his bio See if he would clarify it. I am betting NPR has got something wrong and either misquoted or condensed something to simplify things to make it more reader-friendly.
Another thing I realized is that there is no mention of failure to maintain the place. Not sure if this is on purpose (most likely was) as that would be stepping into something that was/is being litigated if I remember.
In reply to SV reX :
There is a minimum compressive strength for concrete in ACI 318 which is the code Florida uses for structural concrete.
SV reX
MegaDork
7/10/24 8:50 a.m.
In reply to Toyman! :
I'm familiar with that. It's 2500 psi.
I find it hard to believe that supporting columns and foundation supports for a building that size were ever specified by the engineer to allow 2500 psi concrete.
It's likely it's a misprint from NPR.
SV reX
MegaDork
7/10/24 8:55 a.m.
This article (which is much older) seems more accurate. It is linked from that article.
Surfside condo collapse investigation
It discusses extensive corrosion, poor inspections, and bad workmanship and/or design. Doesn't mention the building code.
Mr_Asa
MegaDork
7/10/24 9:03 a.m.
In reply to SV reX :
"All men are mortal, Socrates is a man, therefore Socrates is mortal"
If it didn't even meet code there's no way it would meet any engineering design. Makes complete sense to me.
Not sure it applies in this case, but there is always debate over the building code in effect at the time of construction versus the current code today.
In reply to SV reX :
Surely they meant "weaker than specified by engineering" rather than code. 2500psi is rather low for major load-bearing structures; even here in Arizona, stem walls are 3k minimum.
All that said, of course concrete is strongest in compression. That's all good and well until you get into tension or ductility concerns, which it sounds like may have played a part here (if, in fact, the rebar was corroded).
