Miami Beach, Champlain Towers South apartment building collapse, Part 15 32

[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
Miami Beach, Champlain Towers South apartment building collapse, Part 11
Miami Beach, Champlain Towers South apartment building collapse, Part 12
Miami Beach, Champlain Towers South apartment building collapse, Part 13
Miami Beach, Champlain Towers South apartment building collapse, Part 14

SF Charlie
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[MaudSTL]

Uh oh. Potential trouble in paradise? According to the Miami Herald, it turns out that the Mirage, which is post-tensioned, shares the same architect (and very similar design) as CTS. It has a history that has included broken tensioning cables, large cracks in the deck, cracks and flooding in the garage, long-standing maintenance and condo board issues. Allyn Kilsheimer of KCE and other engineers are interviewed.

Here is an archived version of the Miami Herald’s A lost ‘Champlain’ tower languishes in Surfside. Residents don’t know if they’re safe.

 

[MaudSTL]

Battle lines are being drawn. It’s going to get very ugly. Per the Miami Herald, United in grief, bitter legal battles now divide Surfside collapse survivors and families.

 

[AusG]

Seems to me there is a confusion between emergency relief, insurance, and compensation. Heirs don't need emergency accommodation and new pajamas, but survivors do. Owners or their estates are due the insurance they paid for and whatever saleable value remains, less (I guess) whatever culpability they can be shown to have for the disaster (hence I'm guessing recent posts here about the sacred membrane). Non-owners or their heirs are due at least whatever public liability insurance the building carried. What constitutes compensation per se I don't know. Surfside forking out for approving the thing in the first place? Some state-wide fund from gummint, or levied on the condo business? Grief seems to get deeper the deeper the pockets the compo fund has access to. Stinging Morabito, absent evidence of smoking gun malpractice, will have the effect of making it hard for other condo boards to get professional advice right when they are needing it, which is not helpful.

 

[Pud]

One thing's for sure - lawyers are going to make a fortune.


Politicians like to panic, they need activity. It is their substitute for achievement.

 

[MaudSTL]

The Miami Herald has compiled their reporting to date in an excellent infographic called House of Cards: How decades of problems converged the night Champlain Towers fell. I'm still going through it from the witness statement perspective.

So far, I see that they still start the clock at 1 AM. This means that they continue to ignore the loud cracking sounds heard 22 hours earlier in 1211, and the fact that Chani Nir in 111 was hearing banging starting at 11 PM. So far, the only new witness info I found was the definitive statement that the time stamp of Cassie Stratton's call to Mike Stratton was 1:20 AM...this is the first time I have seen this in writing, so I will update the Witness Timeline with that info. If I find any other new witness info, I'll edit this post and the Timeline as required.

>>>Edit:
I went through the infographic a couple of times. The MH is sticking with their artistic license as mentioned above and also in regard to the time when Sara Nir went to the lobby after hearing the so-called first collapse. In all her initial interviews, Sara said that crash occurred at 1:10 while she was WhatsApping, and she went to the lobby at 1:14. I don’t think this makes any difference from an engineering perspective, but I do think it is inaccurate to claim now that the Nirs heard the first crash at 1:14 when they actually heard it at 1:10..

Another example of artistic license is where they show the crack running down the wall in 611. I can find no statement by Ileana Monteagudo to describe which living room wall cracked. Yet the infographic depicts it on the east side. I would like to see that confirmed by Ms. Monteagudo herself. But for now I still don’t think we actually know which wall developed the crack.

Other than the Stratton call time stamp, I didn’t see anything new or worthy of a Witness Timeline update. Although it makes no engineering difference, I was amused that they added something about the Nirs encouraging Shamoka Furman to join them in leaving the building…that’s the first time I have seen that claim. I feel skeptical about it, considering that Sara did nothing but yell at Shamoka in the lobby. Maybe it’s a little revisionism to make up for Sara’s repeated statements of having had to tell Shamoka what to do, e.g. demanding Shamoka call the cops on whoever was doing construction in the middle of the night, commanding her to pull the fire alarm and call 911 after the deck collapsed (insisting she had to call the event an earthquake,) and having to provide the street address.

 

[Jeff Ostroff]

I always wondered why her husband Mike was so adamant repeating that he distinctively recalled the call happened at 1:30 went the building had already collapsed at 1:22. So I wonder how they got this new timestamp

 

[MaudSTL]

The infographic states that the time stamp came from “call logs.”

 

[Jeff Ostroff]

I mentioned to one of their reporters today about the lady complaining the day before about the creaking concrete building. I too wonder why they never mentioned that. They also did not mention the pool guy seeing the spalling 36 hours before the collapse. My early videos on this mentioned it, and it was in the news, but the spalling was "man-made", as what he saw is what Morabito told the contractor in 2020 to scrape off the Korbel of the pool in 2020. BUT... the pool guy saw pooling water in space #78 at this timestamp of 36 hours before the collapse. That might be of importance, and everyone has left this detail out since then. It was only on the news around June 25 and June 26, then quickly forgotten.

 

[Demented]

Joint testing at last.

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

 

[spsalso]

Looks like the judge knows how to write.

I see that the ONLY .gov's to receive this were miami-dade.


spsalso

 

[MaudSTL]

A new study of sea level rise associates the c-word with the CTS collapse.

https://www.palmbeachpost.com/story...ower-faced-assault-sea-level-rise/9120938002/

Here’s the abstract, which includes a nice tidal graph annotated with hurricanes.

https://www.sciencedirect.com/science/article/abs/pii/S0964569121004518

The abstract states in part, “Historical trends in the elevation of sea-level, King Tides, and hurricane storm surge quantified between 1994 and 2020 reveal the number of times sea level rose to elevations above the building's basement floor increased from an average of 244 per year between 1994 and 2006 to 636 from 2007 to 2020. This is attributed to a 3-fold increase in the rate of relative sea-level rise that occurred after 2006.”

 

[AusG]

Anyone recall an image anytime where a rebar cage sprouting from the garage floor was rusted out? In distance shots some looked incomplete vs others, but in every close-up I recall there was recent surface rust only. The rise of sea level is one of those "gee, it can't have helped any" vague factors that - for this collapse specifically -could be either significant or a red herring.

 

[SFCharlie]

a rebar cage sprouting from the garage floor was rusted out? In distance shots some looked incomplete vs others, but in every close-up I recall there was recent surface rust only.

I vagally recall an NIST photo of an intact portion of a column still attached at the slab, but bent and with what looked like solid rust at the central square of the remains of the connection to the slab.

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[Optical98]

Two new videos:

Building Integrity

Zeroing in on the Initiation of the Surfside Collapse

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

Jeff Ostroff

Best Condo Collapse Theories: Me Or Miami Herald House of Cards?

https://www.youtube.com/watch?v=NySfow1ugm0

Be sure to read the comments on the above video, as Dawn Lehman joins in on the commentary as does Mike Bell.

 

[Jeff Ostroff]

Wouldn't rebar rust anyway after sitting outside for a few weeks in the brutal humid weather and rains that we had down here in Miami?

 

[Sym P. le]

Optical98[/b] (Computer)13 Jan 22 01:39]Building Integrity

Zeroing in on the Initiation of the Surfside Collapse

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

Youtub's Building Integrity gives a well reasoned explanation of why the deck collapse requires rebar failure in tension at the south perimeter wall.

 

[KingBobo]

As I understand it, the theory from Building Integrity is that the rebar connections into the pool deck slab along the south wall of the perimeter bathtub had been compromised. He points out a few early photos showing that the rebar had simply fractured (as opposed to 'zippering' from the concrete), claiming that this supports the idea that the reinforcing steel in that area had been eaten away due to long-term corrosion. With decent close-up inspection of the fractures made shortly after the collapse, it would probably be quite easy for investigators to determine whether the degree of corrosion was extensive enough to conclude that it must have started well prior to the collapse. I don't know how quickly rebar exposed to Surfside weather will rust into nothing, but I'm inclined to think that -- even after a month or two of such exposure -- the remaining cross section of good steel won't be very much smaller than at the start. Of course, any corrosion occurring at the bondline between rebar and concrete will weaken that bond and encourage a zippering kind of failure but not necessarily a tensile fracture of the rebar itself.

 

[AusTony2046]

Assuming that Josh's theory about the slab failing in tension at the southern boundary is correct (and it sounds feasible), on failure, I would expect the southern edge of the slab to jerk away from the wall on failure, but surely it would move no more than a fraction of an inch - Josh estimated 0.4" to 0.5". Had it moved even a few inches, it would surely have taken out all the columns around the upper level parking, but they all remained undamaged.

How would that miniscule movement bring down the building on the northern edge of the slab?

 

[KingBobo]

I believe that Josh is suggesting that the collapse could have been precipitated by something as "benign" as the normal day/night loading cycle. For this to work, we must pre-suppose that the pool deck was teetering on the hairy edge of collapse for quite a while and that those thermally-induced stress cycles in the corrosion-weakened rebar finally produced a fatigue fracture on that fateful night. With the southern edge no longer tensioning the deck (the analogy of those tug-of-war guys letting go of the rope), additional load would have been suddenly transferred onto the columns that was sufficient to initiate the punching shear failures which led to the building collapse. As I recall, there were some load-transferring beams near the building footprint which -- in response to the collapsing pool deck -- could exert a strong moment onto several critical columns supporting the building. This aspect of the design has already been criticized on this forum because it allowed a collapse of the pool deck to threaten the whole building.

 

[spsalso]

So groundwater infiltration at the top couple of feet of soil would cause the rebar to fail at this location? Wouldn't that have called for some sort of waterproofing membrane? Or is such infiltration so unusual that no one thought to do it?

I wonder how long the building would have stood if it had been properly constructed, but keeping the water infiltration at this point. The expansion/contraction at the joint would have remained the same, and the damage to the rebar would have remained the same. Of course, the deck presumably wouldn't fall down. So maybe just a nasty repair job at the failed joint.


spsalso