News Florida Collapsed Condominium had been sinking since 1990s

[Twigg]

Rest of the building likely to be demolished:

If the lingering tower makes it through next week (tropical storm Elsa expected to make landfall early in the week)

 

[russ_watters]

I would have said "certain". How many years of studies would it take to convince you its safe?

Yeah, infinity. I'm not even sure I want anything to do with an adjacent property, much less the attached rest of the building.

The article's wording is a little off (so much of that...), but it implies an imminent demolition. Like, trying to demolish safely and without adding additional rubble on top of the recovery operation, within the next few weeks.

 

[russ_watters]

If the lingering tower makes it through next week (tropical storm Elsa expected to make landfall early in the week)

Yeah, so the article talks about expanding cracks on a day-to-day basis, but isn't specific about where they are. "expanding cracks" on that timescale equates to "collapse in progress". That's what preceded the Pier 34 collapse.

 

[Twigg]

Yeah, so the article talks about expanding cracks on a day-to-day basis, but isn't specific about where they are. "expanding cracks" on that timescale equates to "collapse in progress". That's what preceded the Pier 34 collapse.

Oh oops, disregard my comments

 

[Vanadium 50]

Would be interested to know if there are insurances for complete structure failures.

Yes, but whether the peril is covered or not depends on the cause. Fire, for example, is almost always covered. If the underlying cause was the "sinking" discussed in post #1, maybe not, because Earth motion is in the same category as earthquakes, which usually requires an addition to the policy (called a rider).

It is not impossible that the units destroyed in the initial collapse were not covered but rhe ones that will be destroyed in the upcoming demolition will be.

 

[russ_watters]

Oh oops, disregard my comments

Using my mentor supermediocrepowers for good, I read the post you deleted, and honestly it looked fine to me. Yeah, I don't know how easy it is going to be to bring down the rest of the building safely. If I were a structural engineer, I don't think I'd want to even be walking around in the rest of the building inspecting cracks that are growing as I look at them. And I definitely wouldn't feel good about climbing around on the rubble pile with a compromised structure looming over me.

 

[Astronuc]

Yeah, so the article talks about expanding cracks on a day-to-day basis, but isn't specific about where they are.

I noticed that as well, and that's annoying, since it's critical information. One cannot tell if it's columns of the failed section, or columns in the portion still standing. I read in a different article about cracking or noises from the northwest section, the part still standing but damage when the collapsed section pulled away. I notice floors on the exposed (eastern) face are sagging, so they have been compromised. The foundation or subsurface could be shifting, and I think it likely the structure would collapse onto the existing collapse pile.Edit/Update: Daily Mail, Miami condo collapse: Officials review work of suspended inspector
https://www.msn.com/en-us/news/us/miami-condo-collapse-officials-review-work-of-suspended-inspector/ar-AALFjEH

A Florida building inspector who assured residents of the collapsed tower that it was in good shape a month after being warned otherwise is having all of his previous work reviewed after being suspended from his new job.

Meanwhile, it has also been disclosed that the entire building department for the town of Surfside was under review at the time of the collapse.

Rosendo Prieto was chief building official of Surfside until November 2020. On Tuesday, he was placed on leave from his job as interim building official for C.A.P. Government Inc.

Now, city officials in Doral are planning on reviewing his previous work to make sure he didn't clear other buildings that may be dangerous.

 

[anorlunda]

With all this talk about sinking and salt water intrusion I see no mention of the tides. The former maintenance man mentioned "spring tides" and with tides we have currents. I don't mean swift water currents, but nonzero motion of water that can remove a small bit of material from the karst below the slabs with each tidal cycle. That makes analysis more difficult, and comparison with similar structures less relevant. Even the buildings across the street might have substantially different subsurface conditions.

It would be reasonable to expect all the other high rise buildings in the area to react with "an abundance of caution." A news report earlier this week said that a 6 story condo on the Miami River announced a $1 million per unit assessment to make repairs. Even rich people can find that $1 million here and another $1 million there starts adding up to big money. Couple that with beach erosion and alarmist predictions of sea level rise (my ridiculous neighbor believes 60 m rise this century instead of 60 cm) and what happens to the resale value of those condos? I expect that the owners may soon be financially underwater [inadvertent pun].

 

[Twigg]

I'm glad they're reviewing Prieto's other decisions. I hope for his sake that it was a case of not enough visible information for him to see the problem, and not gross negligence; however, given the 2018 reports that seems unlikely. Hope he remembers how to flip burgers.

It seems like rescue efforts have resumed according to NPR. Putting this all together, it seems that (1) there are expanding cracks somewhere in the structure, (2) either the cracks aren't in a critical location or the first responders are risking it anyways to try and find survivors before Elsa makes landfall, and (3) they are planning to take down the lingering building safely (?) assuming it doesn't collapse on its own in the next week or so.

Using my mentor supermediocrepowers for good, I read the post you deleted, and honestly it looked fine to me

Since my now-deleted comments seem relevant again, I'll repeat them here. Imagine you got the the job to demolish the remaining tower. Normally, you'd go to the city government office and grab the building plans, and spend a lot of time planning what features to manually cut and where to place explosives to bring down the building in a controlled manner. This time, the building is progressively collapsing, you don't know how much of the planned structure has failed, and you probably can't send anyone inside or underneath. You're also on an accelerated time table to bring the building down safely before it comes down whichever way it pleases. It will probably be wet, if the building survives the storm, and you still have all the usual hazards of working with explosives (imagine you push the detonator button and nothing happens. What do you do?). TL;DR version: YIKES!

The media seems to be repeatedly asking about the use of drones/robots for rescue work. I know no one has brought it up here, because I think the folks on this thread all know it's for the most part a ridiculous proposition. But since it's taken public interest, I just want to comment briefly. I'm under the impression that even the internet-famous dancing robots of Boston Dynamics don't have the agility to walk over a debris field, much less have the smarts to search for survivors (putting aside the not-killing-them during rescue aspect of things). I assume tread or wheel based machines don't stand a chance with this much physical obstruction. This doesn't even touch on the issue of on-the-spot problem solving capability that's necessary for unpredictable situations. What I can see being useful here are remote-controlled drones with IR cameras for looking for heat signatures (survivors, fires inside the debris pile, etc). Also drones with regular cameras for inspecting inaccessible parts of the remaining structure (even if it doesn't totally collapse from the ground up, it's just as bad if it starts raining cinderblocks from the top).

 

[artis]

@Twigg your assessment of media hype is well correct but I personally think that IR cameras are of little use here because I doubt a human body's heat signature can be captured if that body lies beneath several layers of reinforced concrete floor slabs. A building type like this when it collapses it doesn't turn into dust instead the vertical columns break and fall sideways while the large floor slabs just pancake one on top of the other they break apart but still they cover a large area much like sheets stacked on top one another.
I'd say regular cameras on long extensions work better here as they can be inserted into the maze of rubble.
As for the remaining structure my personal bet is that left as is it would collapse downwards just like the other part did and as most buildings do whether accidentally or in a controlled demolition the reason I think is because the vertical downforce due to gravity is much larger than any other lateral force that would sway the structure sideways , I mean you would need an extremely strong wind to blow a heavy 12 story concrete structure sideways but the weight of the building on the other hand is quite enough to make it fall vertically down even if the first weak spot or break happens asymmetrically.

In fact I think we all know of an infamous real life proof of this. Remember the 9/11 World Trade Center's south tower which got hit asymmetrically in one of it's corners where the most mechanical damage and heat load was located , when it started to collapse it's upper roughly 25 floors started to fall asymmetrically to one side , you can even see in the videos the whole upper part tilting visibly and strongly to one side at that point it even seemed it will topple over and fall on the adjacent buildings and streets but as it fell it rather soon "straightened" itself out and by the end of it the collapse was rather symmetrical and pretty much within the footprint of the building.
The reason I think is this, because for a heavy structure the downwards force due to gravity + inertia from movement (after collapse has initiated) is much much larger than any other lateral force like wind or asymmetrical breakage point within the structure.

 

[Astronuc]

Cassie Stratton was on the phone with her out-of-town husband, looking down from her fourth-floor balcony in horror as part of the pool deck below apparently vanished into a sink hole.

She "told him that the pool was collapsing, that the ground was shaking and cracking," Stratton's sister, Ashley Dean, told CNN's John Berman. "It's my understanding that she let out a very loud scream and the phone went dead."

https://www.cnn.com/2021/07/03/us/surfside-condo-collapse-questions-unanswered-invs/index.html

from what is known to date, the tower's cave-in resembles less a cataclysmic event than a slow-motion catastrophe, made possible by years of missed warnings, mixed messaging and delayed action, according to public records, including emails and inspection reports, as well as experts who have spoken with CNN.

The true toll of the collapse, of course, remains buried in the rubble. Authorities have confirmed at least 22 deaths, along with 126 unaccounted for.

In recent years selling prices in the building have remained high. A week before the disaster, a three-bedroom condo there sold for $710,000, according to realty company Redfin. The price of most condos ranged from $295,000 (for a one-bedroom in March 2020) to $980,000 (for a three-bedroom a year later), real estate records indicate.

Morabito Consultants, the engineering firm hired to conduct the review, noted "abundant cracking and spalling" in concrete columns, beams and walls, "exposed, deteriorating rebar" and failing waterproofing beneath the pool deck and entrance that was causing "major structural damage."

Also, a photo taken that year by a mechanical engineering firm shows a crack around the edge of a beam running along the top of the room. Engineers and experts consulted by CNN said it appears the same crack is visible in a photograph of the pool equipment room taken just days before the collapse -- only the latter photo, first published by the Miami Herald, shows the crack in much worse condition.

Mounting repairs and sticker shock: 'This is where we are now'

About a month after the report was released by Morabito, a condo association member, Mara Chouela, forwarded a copy of it to Surfside's building official, Rosendo Prieto. Prieto came to the board's regular meeting a couple days later and shared his professional opinion, saying the building appears to be "in very good shape," according to minutes of the meeting.

 

[anorlunda]

There is more to question than just the engineering. If building management is the responsibility of the condo associations, and the boards of those associations are staffed by residents, then most will be amateur. Worse, board members are not only inexperienced, they are conflicted.

Perhaps building codes for multifamily dwellings need to be expanded to cover not only design and construction, but also ongoing management and finance.

 

[Twigg]

@Astronuc, knowing (assuming it's true) that Prieto saw the report ahead of time, I take back my previous statement. No one should trust this guy with flipping burgers even.

I'm sure you all saw, another condo building, Crestview Towers, was evacuated after the emergency review process on buildings older than 40 years showed structural damage that had been reported back in January 'of this year (haven't seen any media outlet elaborate on what variety of damage it was). At least some good may be coming out of all this.

 

[Vanadium 50]

Perhaps building codes for multifamily dwellings need to be expanded to cover not only design and construction, but also ongoing management and finance.

Why just multifamily?

 

[anorlunda]

Why just multifamily?

Fair question. Modern life is full of arbitrary distinctions like that. You need a license to drive a car, but not a bicycle.

 

[Astronuc]

@Astronuc, knowing (assuming it's true) that Prieto saw the report ahead of time, I take back my previous statement. No one should trust this guy with flipping burgers even.

I posted about the article that indicated that Prieto has been put on leave from his current job and all of his work is now being investigated.

Rosendo (Ross) Prieto has recently claimed he did not 'see' the report (hard to believe), but then went to a board meeting and told that the building was in 'very good condition'. If he had not seen the report, then he gave an uninformed, unsubstantiated opinion (that by itself would be gross negligence). On the other hand, there is evidence Prieto did review the report and discussed it with condo board members, and still told the condo folks that the building was in "very good condition". Again, that is "gross negligence" bordering on criminal negligence.

"Surfside records also show that a condo board member sent the report to Prieto before the 2018 meeting and the two met in his office to discuss the matter, according to the article," and he was subsequently invited to the condo board meeting." After the meeting at Prieto's office, a board member wrote, “Thank you so much for having us in your office. We appreciate your time a lot. We would like to invite you to our board meeting on [Thursday, Nov. 15, 2018] at 7:30 to explain the facts of the 40-year inspection,” Mara Chouela reportedly wrote. "

https://nypost.com/2021/06/29/ex-surfside-boss-on-leave-at-new-job-after-damning-report/

A review of the minutes of a condo association meeting by the newspaper found that Prieto told the board he had indeed reviewed the troubling report by engineer Frank Morabito.

WT*?!

 

[Twigg]

Yeah, I'm starting to think Mr Prieto would look reaaaaally good in orange.

 

[fresh_42]

Why just multifamily?

The number of floor levels is probably the better distinction.

However, people know for decades if not longer that Istanbul is built on shaky ground. They do have adequate directions for any buildings. Nevertheless, people did not stop building houses illegally and wildly.

I have to say more about the comparison, and why it is not completely off, but that will lead me on political ground, so I make only one comment about 'lessons learned': Did anybody else than I followed the current political debate about modernizing the country-wide infrastructure? I think the best that can be achieved are regulations for Miami and maybe some other cities will follow the example.

 

[Twigg]

knowing (assuming it's true) that Prieto saw the report ahead of time,

@Astronuc sorry, the "assuming it's true" wasn't aimed at you. I was just acknowledging the fact (I thought) that we only had Mara Chouela's claim that Ross Prieto had seen the report. Now that I see there is an email record that can be subpoena'd, it's a very different story.

 

[Astronuc]

@Astronuc sorry, the "assuming it's true" wasn't aimed at you. I was just acknowledging the fact (I thought) that we only had Mara Chouela's claim that Ross Prieto had seen the report. Now that I see there is an email record that can be subpoena'd, it's a very different story.

I didn't take it personally. Like you, I can only go by what is reported, which may or may not be valid, or perhaps, part of the story. As time goes by, more evidence becomes revealed, and it seems to be piling up with respect to Prieto's negligence, which is still only part of the story.

The investigation will have to look into the site characteristics (did a sinkhole open up, i.e., was the supporting ground unstable and why), the design (was the design appropriate), the construction (was the construction methods and materials appropriate), the maintenance (it appears the maintenance was deficient), the inspection process (seems to have been appropriate), the government oversight (clearly (in hindsight) there are those that feel the oversight was lacking).

 

[Lnewqban]

I posted about the article that indicated that Prieto has been put on leave from his current job and all of his work is now being investigated.

Rosendo (Ross) Prieto has recently claimed he did not 'see' the report (hard to believe), but then went to a board meeting and told that the building was in 'very good condition'. If he had not seen the report, then he gave an uninformed, unsubstantiated opinion (that by itself would be gross negligence). On the other hand, there is evidence Prieto did review the report and discussed it with condo board members, and still told the condo folks that the building was in "very good condition". Again, that is "gross negligence" bordering on criminal negligence.

"Surfside records also show that a condo board member sent the report to Prieto before the 2018 meeting and the two met in his office to discuss the matter, according to the article," and he was subsequently invited to the condo board meeting." After the meeting at Prieto's office, a board member wrote, “Thank you so much for having us in your office. We appreciate your time a lot. We would like to invite you to our board meeting on [Thursday, Nov. 15, 2018] at 7:30 to explain the facts of the 40-year inspection,” Mara Chouela reportedly wrote. "

https://nypost.com/2021/06/29/ex-surfside-boss-on-leave-at-new-job-after-damning-report/

WT*?!

After having worked with several Building Departments in South Florida, I wouldn't pay any attention to the technical opinion of any Building Official.
Even with the purest original intentions of protecting the public at the time of taking the job, most of these experienced Building Inspectors become political subjects within a jurisdiction administration power drama.

Their main priority becomes the pleasing of rich influencial citizens, as well as of town/city administrators who could terminate their employment.
If that means bending the Building Code a little and overlooking some violations, so be it.

Personally, I have not met one that could run a structural calculation or an accurate assesment.
Clearly and sadly, this condo association did not think the same way that I do, reason for which they seeked and trusted the opinion of Mr. Prieto.

Copied from
https://en.m.wikipedia.org/wiki/Building_officials

"Building officials of developed countries are generally the jurisdictional administrator of building and construction codes, engineering calculation supervision, permits, facilities management, and accepted construction procedures."

 

[russ_watters]

Why just multifamily?

Shared risks/responsibilities and conflicting interests are hard to manage.

 

[russ_watters]

Looks like the rest of the building is going to be demolished tomorrow:
https://www.usatoday.com/story/news...emolition-planned-within-36-hours/7851388002/

 

[Astronuc]

Looks like the rest of the building is going to be demolished tomorrow:
https://www.usatoday.com/story/news...emolition-planned-within-36-hours/7851388002/

I wonder if they will give the residents time to collect some of their irreplaceable valuables. Or do they consider it too dangerous.

 

[russ_watters]

I wonder if they will give the residents time to collect some of their irreplaceable valuables. Or do they consider it too dangerous.

Sounds like no, in the article.

 

[artis]

@Astronuc I think those who got out already collected their most irreplaceable valuable namely their own life. Going back one more time would risk loosing that single most precious valuable.

 

[artis]

This is a rather nicely made video echoing my own viewpoint , One thing I've noticed from both this video and other pictures is that for a rather large structure like this a 12 story building the main columns seem rather thin , also in the video he talks about the seemingly different thickness of columns where the ones that were located in the part that was left standing are much thicker.
Not saying this is the cause of anything but interesting nevertheless.

 

[anorlunda]

This is a rather nicely made video

Thanks for sharing that. The video is very detailed and instructive. I recommend it to everyone here who wants to discuss the collapse.

 

[Astronuc]

he talks about the seemingly different thickness of columns where the ones that were located in the part that was left standing are much thicker.

Thinner columns, which appear to be the case, would be more likely to buckle or shear, i.e., the loads at which they buckle/shear would be less. That the rest of the building is standing may be in part due to the larger columns. Questions remain as to the integrity of the columns at the base of the collapsed building and the foundation and subsurface ground underneath.

It's notable that the columns of the garage are still standing even after the pool deck/lower garage roof collapsed, which would imply that the rebar gave way and the deck structure sheared away from the columns. The garage didn't tall into a sinkhole, but the lady who mentioned it probably saw the garage deck drop into what she thought was a sink hole.

Early in the video, about 5:10, with the motor sitting on a slab and the pool pump sitting on a piece of wood on a cinder block. I agree about the criticism of the pool pump support, but the other motor seems to be on a concrete or cement slab (pad?), or a raised portion of the floor. I have seen that practice in many basements. It is design to let water run off if there is a pipe rupture and the idea is to prevent flooding of electrical equipment. One would not want to use aluminum RTU brackets (~5:39) because they would corrode in the dampness with chlorine or sea salt present.

The video mentions Architects Journal. I found one site -
https://www.architectsjournal.co.uk...apse-engineers-early-theories-as-to-the-cause
I haven't found the colored image of the building indicating the sections that collapsed by order.I have heard one report (I have not substantiated/verified) that the amount of rebar was insufficient. That will be revealed in an investigation.

I think the demolition will bring the building down on to its foundation and possibly onto the existing debris pile.

@Astronuc I think those who got out already collected their most irreplaceable valuable namely their own life. Going back one more time would risk loosing that single most precious valuable.

True, but for some it's all the mementos (e.g., pictures of family members) and personal gifts from family and friends, and possibly legal documents, that are just as important as their lives. But they have been told they will not be able to re-enter the building.

 

[Borg]

For those looking for the inspection reports, the city of Surfside has posted them all in one place on their website:
https://surfside.one/public-records-search/