Florida Collapsed Condominium had been sinking since 1990s

[artis]

The first slab is the floor of the underground garage, and the slab should be attached by rebar to the columns. If the rebar in those joints failed, then the columns could drop into the ground underneath, which would compromise the structure above.

I would also tend to think that even the base slab that rests on ground is connected by rebar to the columns but in a building with 12 stories I would suspect that the columns themselves actually start well below the base slab (the floor of the parking garage) and are actually built on top of piles driven into ground or some anchoring. If the columns actually ended on the base slab then they would puncture right through the slab and drop to ground a soon as the building is finished being built. Or you would need an extremely thick slab , I'm thinking like a meter thick or more. So I think the slab is thin it just does the floor function and some lateral bracing of columns while the columns themselves have to rest on some deeper anchoring, especially in a soft ground like that next to ocean.So continuing our online investigation , here is a video that I found quite randomly, it seems to show a large part of the underground garage. In the end you can see the exit ramp for cars that was filmed in the tourist video with the leaking water pipe. You can observe plenty of pipes on the ceiling from fire water ones to some other ones. If that pipe burst because of the yard slab failure being at the other side of the slab it would indicate that the rest of the slab underneath the structure was heavily compromised. The most likely damage to the pipe could have resulted from large heavy portions of the concrete slab dropping freely and hitting the pipes in the process.
As for the column thickness well it seems that they were the same thickness throughout the structure , at least at the basement level because the part of the parking garage with the exit ramp seen in the video is the very part that collapsed.
Truth be told apart from a few cracks here and there the slab doesn't seem to be in such an extremely bad conditions like it is told on news. Lastly I hope this is the video of the building in question but it definitely seems so from the floor plan and exit ramp.

Lastly take a look at this video , a short clip by someone from the rescue team as they are working under the collapsed section in the parking garage. Take notice of the ceiling slab, the one that I think could be responsible for the compromising of columns. Notice how the rebar has separated from the slab and left deep trenches in the half fallen slab piece under which the people are working. It could very well be that similar damage happened under the building as the yard slab portion fell, rebar being metal has high tensions capabilities and it could have exerted a large pull on all the adjacent structure.
Also at the very beginning of the video take a close look of one of the columns and see how the slab has separated from the column and fallen down yet the column is left standing.


This is a picture under the half part that was left standing , notice how the failure of the yard slab has carried on through the rebar into the slab underneath the building.

I must say those people working in that hellish unsafe environment risking their lives should get all the respect they deserve.

 

[artis]

Here's a guy who has made a video with all the columns and the first floor slab which seems to be the place where failure started.

 

[artis]

One thing that hasn't been talked here as far as I see is about survivors.
Sadly I think there won't be any more survivors past the first ones that were found, there are mostly 2 reasons for that , first is time, living under rubble without water or food and with possible injuries can only last you a couple of days at best in most cases.

But the second reason is that I think most of the folks died upon collapse, in a structure like this the floor slabs being made from concrete they are heavy and as the building comes down those slabs literally fall one on top of the other. Being as heavy as they are ordinary apartment items cannot slow them down or stop them they annihilate everything from fridges to TV's and furniture , everything gets absolutely flattened under the weight and inertia so I would think anyone who was as the part of the collapsed building somewhere between the very top floor and basement got compressed to a coin.

See in the pictures how the balconies are sitting one atop the other with just inches of space between what was once a whole floor between.

 

[anorlunda]

Clearly the board did not understand the gravity of the situation

The board is comprised of residents with no particular qualifications. Can any condo board anywhere be expected to correctly interpret an engineering report? The condo board should be required to also hire an engineering firm to carry it a step further; to produce a detailed list of remedies that must be performed including schedule. The detail must be enough to present to possible bidders as an RFP.

In no case should we expect condo associations to competently decide engineering questions or even to understand them.

 

[Astronuc]

Can any condo board anywhere be expected to correctly interpret an engineering report? The condo board should be required to also hire an engineering firm to carry it a step further; to produce a detailed list of remedies that must be performed including schedule. The detail must be enough to present to possible bidders as an RFP.

A colleague owns an apartment in a condo in a major city. He was probably the only engineer on the board when he joined several years ago, and he made things happen, such as roof repair and proper ventilation that had been neglected to the point where apartments were suffering damage. And he had to deal with members who did not want to pay for repairs/improvements, much like the situation at CTS, but not as critical.

Going forward, there will probably be changes in the local and/or state laws, or mandates pushed by insurance companies, to impose more responsibility onto condo associations and/or owners of condos to ensure proper structural inspections. If there was less rebar in the columns and/or beams, especially in the joints, or if the columns were indeed undersized for the structure, then something went wrong in the construction and inspection/certification phase, so that will have to be addressed.

What agency/law would require a condo board to hire an engineering firm? Morabito Consultants (an engineering firm) was hired to do some kind of assessment in preparation for the 40-year review and recertification. MC warned of damage to the structure. The town inspector declared the building in "very good shape", so apparently the board concluded that the building was in very good shape despite MC's warnings. A 'timely fashion' for repairs would have been 2019 (@38 years), not starting 2021 at 40 years.

On the other hand, I'm troubled by the statement in the MC report (item J), "Though some of this damage is minor, most of the concrete deterioration needs to be repaired in a timely fashion. All cracking and spalling located in the parking garage shall be repaired in accordance with the recommendations of ICRI." The statement would be reasonable if the damage to the concrete was superficial (or minor), which in places it might have been. But the use of minor seems to undermine the severity of the situation. Even if it was minor, it was surely going to be major or critical at some point, because that is the nature of corrosion and environmental degradation.

Perhaps the requirements for a 40-year recertification don't go far enough, since MC didn't appear to do a full structural integrity inspection, and I'm sure MC did not expect apparent inadequacy in the rebar (if that proves to be the case). And look at the language in item K.

Does the 40-year recertification process require a full structural integrity assessment/inspection, i.e., would it require that the integrity of the rebar be inspected with GPR and/or X-ray?

MC offered to work with the CTS association board in the last paragraph, "MC trusts this initial report will assist the Champlain Towers South Condominium in understanding the required maintenance that is needed to properly maintain this existing residential property. MC is available to further discuss the recommended repair work and how it coincides with the owner's desires and constraints. We look forward to working with you in maintaining the structural integrity of the Champlain Towers South Condominium." Was that enough? How far does MC have to go to ensure the board 'understands'? In items J and K, MC states "All cracking and spalling located in the parking garage shall be repaired in accordance with the recommendations of ICRI."(J) and "All repaired concrete slabs located in the parking garage are to be
repaired in accordance with the recommendations of ICRI"(K). It's not clear on the followup.

I'm curious about the popping sounds in the apartment building/garage. Did they happen just before the collapse, or had they been happening for days before?

In no case should we expect condo associations to competently decide engineering questions or even to understand them.

But don't they have to be competent enough to hire an engineer to evaluate/assess a building's structural integrity? After all, aren't the owners responsible for ensure the structural integrity of their property? Sounds like there needs to be some law(s) or government regulation(s).

 

[Keith_McClary]

to impose more responsibility onto condo associations and/or owners of condos to ensure proper structural inspections.

If you put personal responsibility/liability on board members, nobody will want to serve on the board.

"MC trusts this initial report will assist the Champlain Towers South Condominium in understanding the required maintenance that is needed to properly maintain this existing residential property. MC is available to further discuss the recommended repair work and how it coincides with the owner's desires and constraints. We look forward to working with you in maintaining the structural integrity of the Champlain Towers South Condominium." Was that enough?

I would read that as a standard sales pitch that they tack onto every report.

 

[anorlunda]

Normally, I'm libertarian by nature. But this example sure seems to point to the need for new regulations/laws.

What would make sense in cases where there are thousands of similar condo owned buildings is to pool resources to hire a professional building management company to do most of the things that are today handled by the residents. The management company should have a legal fiduciary duty.

 

[artis]

Well I somewhat disagree with the assessment that owners need to be told like children what to do.
I am not a doctor or a surgeon but when I have legitimate concerns over my health I call one.
A building owner doesn't have to be a structural engineer but we all have eyes and if we see or hear or witness whatever we should simply call the "doctor".

I don't want to sound judgemental on people that have passed away horribly but eventually reality is reality and for every mistake there is a person or surname that is attached to it and in this case I do feel that the very people that died were somewhat responsible for this.
The same happens with folks and their health I know many folks who feel sick yet they disregard that as "no biggie" only to find months later that they are taken to intensive care and now the illness is vast and raging and often they die in the result from something that could have been treated easily.
Who is to blame in such a case? Should we now have laws that mandate everyone to sit right next to a doctor 24/7?

The problem is that even when people tend to worry about their own health very few would ever think that a building that they only partially own also needs some looking after. It's just how people are , we are essentially selfish and tend to disregard threats that are hard to understand or that are not visible. So I guess @anorlunda suggestion of tougher building evaluation and them being mandatory after certain intervals is the best option.

 

[artis]

@Astronuc as for the building evaluation in 2018, here I would say that if that building collapsed like it did only 3 years later I would say that a cosmetic repair or otherwise would not have made much of a difference, here is why I think that.
When you have reinforced concrete structure , when the rebar has rusted away and the concrete has cracked there is not much you can do further on, sure you can cover the cracks but concrete accumulates moisture through it's very self so there will still be further moisture and further rusting inside.
Also whenever pieces of concrete have fallen off , what is the remedy ? To patch new concrete in place? I'd say no, here is why I think that.
Whenever you cast concrete whether in factory pre-cast panels or on site you form it as a single monolith, when that concrete dries if it then later fractures or forms a void the new concrete or other material that will be put into this crack or void won't restore the same structural integrity that it originally had.

Like imagine taking a jack hammer and cracking out some pieces from a reinforced concrete panel or slab, then patch that hole with fresh cement made on spot say by hand or whatever , that new cement patch will never have the same adherence or load bearing capability the original uninterrupted slab/panel had, so it's structure will still be weakened.
This is much worse ofcourse when there is rusted rebar underneath.

I would say that beyond a certain point of rebar rust and concrete cracking and spalling there is no going back , patching up cracks is just making it seem pretty but structurally the load bearing is not and will not be there.
I would say that given how totally the structure failed and all the possible weak spots it had, even the year 2018 was too late to do anything useful in the long term , Id' say that building needed to be assessed professionally and then vacated peacefully and demolished. Or at least the yard slab needed to be demolished and rebuilt completely , although I'm not sure how one could do that and how that would have affected the structural integrity of the remaining tower.Anyway patching concrete is like heat soldering broken plastic, yes it can be done but the soldered part will never be as tough as the original.

 

[anorlunda]

It's just how people are , we are essentially selfish and tend to disregard threats that are hard to understand or that are not visible.

Yes. To make it worse, consider the case where the necessary repairs are more than the residents can afford. If unaffordable, the option is to abandon the building and their investment in the building and to shoulder the expenses of demolition. How many would vote to accept that conclusion? How many if most residents are retired and have most of their net worth tied up in that real estate investment?

@russ_watters said it best that shared responsibility and conflicted interests are hard to manage. Now compare how to manage that in the case of a commercial building compared to a condominium owned building. As a 76 year old senior myself, I would add a third case to compare -- a condo owned by residents all over 70 years old.

This incident shines the light on the basic business model of condominiums. This is an engineering forum, and it's natural that we are most interested in the engineering details, but preventing future repeats requires a hard look at the social side also.

 

[Rive]

as for the building evaluation in 2018, here I would say that if that building collapsed like it did only 3 years later I would say that a cosmetic repair or otherwise would not have made much of a difference

Any relevant kind of 'cosmetic' repair includes removing loose parts and assessing the integrity of the remaining material, since cover up is possible only if the reserves are still adequate.
So starting that 'cosmetics' may not have been able to prevent the collapse of the building, but it could have been made it done in a controlled way (by a demolition brigade).

Ps.: worth noting that exactly due this 'cosmetics' is also a serious engineering stuff, especially in case of (reinforced) concrete.

 

[Astronuc]

@Astronuc as for the building evaluation in 2018, here I would say that if that building collapsed like it did only 3 years later I would say that a cosmetic repair or otherwise would not have made much of a difference, here is why I think that.

I don't believe MC (2018) called for 'cosmetic repairs', but then I don't know what MC meant by "All cracking and spalling located in the parking garage shall be repaired in accordance with the recommendations of ICRI". What would are the recommendations of ICRI in this case? MC did indicate that previous repairs had failed, or were failing: "MC visual observations revealed that many of the previous garage concrete repairs are failing resulting in additional concrete cracking, spalling and leaching of calcium carbonate deposits." Leaching of calcium carbonate indicates a severe problem.

There is an ICRI document - 310.1R-2008 (English PDF) - Guideline for Surface Preparation for the Repair of Deteriorated Concrete Resulting from Reinforcing Steel Corrosion. Would that have been recommended and employed in the repairs. I would hope so.

See page 5, Slides 27-30, which call for concrete replacement.
https://cdn.ymaws.com/www.icri.org/resource/resmgr/2016_fall_convention/1_Fri_02-F2016.pdf

See also Discussion in - https://www.concrete.org/Portals/0/Files/PDF/3646t_02-11.pdf

The decision to undercut the reinforcing bar should be made based on the chloride ion concentration and/or extent of carbonation in the surrounding concrete. There is a high risk of continuing corrosion whenever, at the reinforcing steel level, the acid-soluble chloride content by weight of cement exceeds 1% (ASTM C114) or cement paste is carbonated. Significant contamination may require the removal of existing concrete surrounding the bar. Such a removal will avoid creating an environment where part of the circumference is depassivated and another part is still passive, a combination that may lead to accelerated corrosion.

The damage to the columns would have to be inspected on an individual basis. If their load bearing capacity was reduced, then they would have to be replaced or the damaged portion would have to be replaced, and if some observations are correct, the proper rebar installed. It is certainly not a trivial matter. Otherwise, the thin columns would require steel collars or some kind of external steel reinforcement that would potentially compromise the parking areas (fewer spaces). My guess is that the cost of repairs would be substantial.

The marine environment is fairly aggressive with respect to corrosion of common structural steels, which are not stainless steels. I know this from a study I did about 5 years ago looking at corrosion resistance of certain structures in the process and nuclear power industry, and looking at failures of structural elements. Even common stainless steels of the 300 series can fail due to stress corrosion cracking with chronic exposure to chlorine/chlorides.

On the other hand, if it is discovered that some of the columns had actually dropped below their initial elevations due to a sinkhole or some ground subsidence, then the repairs suggested above would be moot. But would the ground subsidence have been discovered? It certainly was not mentioned in the MC report (2018).

 

[russ_watters]

Well @Astronuc as for the column thickness I still hold my judgment on that one because I assume that it is a factor that is very hard to conceal and given that back when the towers were built the US was considered and still is considered a first world country I would find it hard to believe that one could pull off such a blatantly visible mistake in one of the country's most popular cities and tourist destinations. But who knows time will tell.

As a practicing mechanical (not structural) engineer in this arena, structural engineering scares the hell out of me. I know nobody is perfect, and despite review processes, mistakes get through. They can even be created during construction and then missed/signed off on by the engineer (Hyatt Reagency walkway). The rate is very low, but the number of opportunities is very high.

 

[russ_watters]

A colleague owns an apartment in a condo in a major city. He was probably the only engineer on the board when he joined several years ago, and he made things happen, such as roof repair and proper ventilation that had been neglected to the point where apartments were suffering damage. And he had to deal with members who did not want to pay for repairs/improvements, much like the situation at CTS, but not as critical.

Going forward, there will probably be changes in the local and/or state laws, or mandates pushed by insurance companies, to impose more responsibility onto condo associations and/or owners of condos to ensure proper structural inspections...

What agency/law would require a condo board to hire an engineering firm? Morabito Consultants (an engineering firm) was hired to do some kind of assessment in preparation for the 40-year review and recertification. MC warned of damage to the structure...Perhaps the requirements for a 40-year recertification don't go far enough, since MC didn't appear to do a full structural integrity inspection, and I'm sure MC did not expect apparent inadequacy in the rebar (if that proves to be the case). And look at the language in item K.

Does the 40-year recertification process require a full structural integrity assessment/inspection, i.e., would it require that the integrity of the rebar be inspected with GPR and/or X-ray?...

But don't they have to be competent enough to hire an engineer to evaluate/assess a building's structural integrity? After all, aren't the owners responsible for ensure the structural integrity of their property? Sounds like there needs to be some law(s) or government regulation(s).

I'm on my HOA board. We're a townhouse commuity and a small one, so the stakes are much lower: Typically in a townhouse the unit owner owns the house and land under it. In a condo the unit owner owns from the drywall in and the association owns the rest of the building.

I'm the only engineer on the board, and not a structural engineer. My work (HVAC and general project management) intersects with structural engineering, but not enough to be an expert. The experience as an engineering project manager would be more relevant here. And I actually have to be careful leveraging my engineering experience due to liability and professional ethics constraints.

The desires of the owners and the desires of the association they belong to do not necessarily align. My community of townhomes are mostly a combination of "starter homes" and rentals. The incentive to fix our roads, for example, is low because if a person plans to move in 5 years they don't want to be paying for 20 years of infrastructure. In both cases (townhomes and condos), the common property has less impact on your property value and quality of life than what is inside your walls.

I worked on a big condo building in Philly, and they are a challenge because their membership is larger and more diverse. You have young "starter home" people and people who have been living there for decades and plan decades more. Their needs/wants often conflict.

And, as discussed, few people have the expertise to assess such things (accounting and legal matters too). The best thing my board has done was to hire a management company and stop trying to do things all ourselves.

But ultimately, the board controls the money so unless an engineer/city licensing and inspection dept actually gets a building condemned, it is tough to enforce/force standards and action. Presumably Morabito could have called the city if they thought collapse was likely/imminent. In Philly we had a road shut down for emergency repairs after an inspector happened to drive by an overpass he'd previously inspected and noticed a large crack that hadn't been there before. So it does happen. In hindsight, the Pier 34 situation was pretty much a "pull the fire alarm and call the police" level of "imminent", but people who witnessed the deterioration beforehand were simply incredulous; how could the owner not be addressing this gigantic crack?

The regulatory requirement for this incident may simply come down to 40 year recertification timeline being too long or lacking power/urgency/decisiveness.

 

[russ_watters]

Any relevant kind of 'cosmetic' repair includes removing loose parts and assessing the integrity of the remaining material, since cover up is possible only if the reserves are still adequate...

Ps.: worth noting that exactly due this 'cosmetics' is also a serious engineering stuff, especially in case of (reinforced) concrete.

Yeah, I would go further to simply say that with the possible exception of paint, there is no such thing as a purely cosmetic repair to a structural element.

 

[Astronuc]

PS on this item. I've been pondering this statement.

"MC visual observations revealed that many of the previous garage concrete repairs are failing resulting in additional concrete cracking, spalling and leaching of calcium carbonate deposits."

I read this as meaning the previous repairs were not done properly, or possibly because, the waterproofing was failing and damage due to chlorinated water and salty water intrusion was persistent.

The standing water, especially if it was saltwater from flooding during hurricanes,storms or high tides, is troubling. It implies the damage was happening to the foundation of the building, as is evident by the degradation of the concrete on the sloped entry (driveway) and floor of the garage, as well as the pool/plaza deck. There should have been some kind of structural integrity assessment, and in retrospect/hindsight, 40 years seem like too long and it should be more like 30 years, or whenever there is observable damage like that mentioned in the MC report.

As a practicing mechanical (not structural) engineer in this arena, structural engineering scares the hell out of me.

As a practicing engineer also, but not a structural engineer in terms of civil engineering, I do special types of structural analyses, and I've been involved in plenty of failure root cause analyses. My clients are typically other engineers or engineering managers. I'm glad I do not have to deal with the public or groups of citizens.

I also know about various codes since I sit on a national standards committee for steel, which covers a wide range of products and applications, including standards for rebar. I know about ACI, AISI, CRSI and other standards, but I do not practice in those areas. I appreciate that it's complicated.

https://www.crsi.org/index.cfm/basics
https://www.crsi.org/index.cfm/standards-certifications

 

[anorlunda]

The regulatory requirement for this incident may simply come down to 40 year recertification timeline being too long or lacking power/urgency/decisiveness.

Plus the fact that only 2 Florida counties require recertification at all, according to the Palm Beach Post

 

[anorlunda]

This article suggests that the market may provide a solution to these old buildings. Rich old people may be displaced by richer young people.

https://www.nbcnews.com/news/us-new...d-reshape-miami-s-real-estate-market-n1273306
Market observers said they have already begun to see diminishing demand for units in older buildings in the area that are typically occupied by lower-income tenants and retirees, similar to the fallen condo, Champlain Towers South in Surfside. And those built since 2000, typically inhabited by wealthier Floridians, are getting greater attention from buyers.
...
“All the best properties were built in the '70s, '80s and '90s on this good waterfront land,” Sasseville said of Miami Beach. “Now you’re going to see what we call condo terminations, where developers buy out old buildings, tear them down and put up new ones.” [emphasis added by me]
...
Another concern is that insurance premiums may suddenly spike, Clarkson said. He recalled that after Hurricane Andrew in 1992, many major insurers left Florida because of the amount of claims and because “premiums were going up 400 percent, 500 percent overnight” due to the lack of competition.

“It becomes a feast,” he said. “And that's what's going to happen again or they're going to issue policies with so many exclusions on it that it’s almost not worth having.”

 

[gmax137]

Plus the fact that only 2 Florida counties require recertification at all, according to the Palm Beach Post

Makes me wonder what is typical, nation-wide.

 

[Astronuc]

One way to keep track of needed repairs is a "reserve study," in which condo boards bring in experts like engineers or certified specialists every few years to inspect buildings and estimate how much the boards should collect from residents to prepare for future fixes. The building's financial documents, obtained by NBC News and NBC Miami, show that Champlain Towers South had not done a professional reserve study since at least 2016. That decision was legal, but it meant that planning was left to the board, a shifting group of volunteers with little training in building maintenance.

https://www.msn.com/en-us/news/us/repealed-florida-law-would-have-required-faster-repairs-at-collapsed-tower-experts-say/ar-AALUvzg

Robaina sponsored a 2008 law requiring condo associations to hire engineers or architects to submit reports every five years about how much it would cost to keep up with repairs.

The law lasted just two years before it was repealed in 2010, after Robaina left office.

I think the building collapse might have been prevented had the columns on the south face of the collapsed portion been more robust, and had proper concrete (for a marine environment) been used. We are waiting for an investigation of the site (ground stability), construction (rebar and concrete), effects of corrosion (samples of rebar and concrete from the failed columns), . . . .

More robust inspection, certification and recertification programs are needed.

And the town building inspector who told the CTS association board should be investigated for negligence.

 

[Keith_McClary]

'Condo wars:' Surfside association fighting in Florida was extreme, but it's a familiar battle for HOAs​

Long before the Champlain Towers South Condominium collapsed, the owners and the complex's board of directors spent years clashing over the cost and extent of safety and structural repairs for the 12-story building near Miami.

"Why is all of this so complicated and expensive?" read the question that topped the board's meeting minutes over a list of major structural problems last October as the deadline for a state-required recertification of the Surfside, Florida building approached.

On April 9, Jean Wodnicki, president of the Champlain Towers South board, warned in a letter to owners that the problems had worsened. “We have discussed, debated, and argued for years now, and will continue to do so for years to come as different items come into play,” she wrote.

"A lot of the work could have been done or planned for in years gone by. But this is where we are now," added Wodnicki.

The disagreements represent an extreme but familiar version of the infighting and financial planning battles that play out across the nation in condos, homeowner associations and co-ops — roughly 380,000 community associations in all. Owners or shareholders of the associations square off with volunteer and sometimes inexperienced board members elected to oversee the complexes in a struggle to maintain aging buildings while keeping monthly fees low and enticing new buyers.
...
the Champlain Towers South Board "was struggling and struggling and struggling" for years to gain approval from unit owners to fund costly repair work, and "finally got it over the line" shortly before the collapse.

 

[Astronuc]

Allyn Kilsheimer is Investigating a Building Collapse by Studying Clues From One Still Standing
https://www.msn.com/en-us/news/us/investigating-a-building-collapse-by-studying-clues-from-one-still-standing/ar-AALYLqU

The death toll at CTS is up to 86, with about another 43 or so missing.
https://www.msn.com/en-us/news/crime/will-anyone-face-criminal-charges-over-surfside-condo-collapse-heres-what-experts-say/ar-AALXUE2?li=BBnbfcL

There is concern that some older condo buildings may be compromised, or simply bought by a developer, demolished and a new structure built, which would price many people out of the area.
https://www.nbcnews.com/news/us-new...d-reshape-miami-s-real-estate-market-n1273306Meanwhile, "A historic courthouse has been evacuated after engineers identified "safety concerns" following a review of the building's structural integrity that was prompted by the deadly collapse of a Miami Beach-area condo building, Miami-Dade County officials said Friday night."
https://www.nbcnews.com/news/us-new...ing-inspection-finds-safety-concerns-n1273613

The courthouse, completed in 1928, is where most civil cases are heard. The 28-story building also houses some administrative offices.
. . .
Problems with leaks, mold and issues with the courthouse's facade have been reported at the building over the years. But Miami-Dade County is currently in the early stages of construction of a new civil courthouse, with plans to sell the historic building.

 

[artis]

For those that are interested. Here is a nice recent video of the same guy I already posted here earlier , truth be told of all the wannabe experts and amateurs on youtube this youtuber seems like a solid man. Some details might be irrelevant in his video but overall the detail he is showing and the homework he has done is quite amazing.

Take notice when he examines the tourist video and indeed it seems like the some columns had failed before the whole collapse. Also at the end where he has some of those garage photos indeed there seems to have been some columns tied to others via additional support which could have proven fatal in terms of lateral pull.

Also one thing I just realized that a flat on site cast floor slab when it gets wet, not only it impacts the rebar inside it but since most concrete is rather porous the slab accumulates weight overtime, since concrete dries very slowly and in frequent rains and moisture not at all.

 

[artis]

Here is another good short video from the news this time, so much truth said in such little time , why can't all modern news be like this.

 

[artis]

Seems like improper building techniques are not that uncommon , just most are minor and probably they get away with it while others are major and end in this

 

[Gary_T2018]

The most shocking part of the whole tragedy it seems is that both the professionals hired by the homeowners to inspect the building and the government-dispatched surveyors had knowledge of the extensive or at the very least, conspicuous damages caused by the flawed implementation of the drainage scheme, since exposed rebars were easily observable.

Yet no one proposed the evacuation or condemnation of the building. This is highly unusual! Either these technical workers have this overconfidence which enabled them to draw the conclusion that the damage wasn't in anyway substantial, or they failed to perform due diligence and go that extra mile out of their league and their line to the higher-ups or the media to expose this, or most likely, they genuinely didn't understand how bad things were. They studied the schematics of the building, and neither their academic training nor their working experience was sufficient for them to understand how potentially disastrous the damages could be.

It's astonishing and alarming that none of these people have the kind of professional paranoia that made them go hyperbolic almost immediately upon finishing the inspection. Imagine a flight safety inspector detected cracks in the fuselage but simply filed a report and called it a day.

What were they thinking?

 

[russ_watters]

@Gary_T2018 your post has been moved to the existing thread on the subject.

To reply; this incident is one in which most of the degradation likely happened in places that couldn't be observed, making it difficult to know when the building's collapse became imminent. But we'll be learning more as the investigation proceeds...

 

[Tom.G]

An 8 minute video animation of collapse based on event video and architectural plans. Dated July 26, 2021



Cheers,
Tom

 

[swampwiz]

Florida below Orlando is geologically limestone covered with beach sand. The latter is quite weak, and the former is subject to acidic intrusion, which is why there are so many sinkholes and flooding far away from the coast on sunny days.

This is the just tip of the tropical iceberg. There will be more towers that collapse, and sea-level rise will make Miami unlivable unless everyone moves their homes & streets up.

 

[BillTre]

I have seen plans on TV where they want to build a big wall (sound familiar?) to keep out the water.
The porous bedrock would seem to make this fruitless.

 

[artis]

Unless they are willing to extend that wall down to hell itself... , then indeed such a project might seem fruitless in that place.

 

[Astronuc]

The video shows densely packed steel reinforcement in various sections of the building, along with extensive corrosion where one column met the building's foundation.

"The corrosion on the bottom of that column is astronomical," Dawn Lehman, a professor of structural engineering at the University of Washington, told the Miami Herald. She said that amount of corrosion should have been obvious and documented as part of the 40-year inspection that was ongoing when the building in Surfside, Florida, collapsed June 24.

https://www.npr.org/2021/08/26/1031245430/surfside-condo-collapse-corrosion

While it's already congested with rebar, at the splice regions, it would have been "even further congested," Aghayere told the Herald.

He said he was struck by how "powdery" and white the concrete in columns appeared in the newly released video. Stone-like aggregates used to strengthen concrete during construction typically remain visible but they were not in the images from the collapse site.

"The white color just stuns me," Aghayere told the newspaper. He added that instead of seeing aggregate material mixed into the concrete, "it's just homogenous," which is likely indication of saltwater damage.

A recent article suggests, "Collapsed Surfside Towers Actually Broke Building Code From the Very Beginning". Apparently, other high-rise building may face repair or demolition.
https://www.curbed.com/2021/08/miami-condo-collapse-structural-flaws.html

WSJ - Behind the Florida Condo Collapse: Rampant Corner-Cutting - Inadequate waterproofing, thin columns and faulty concrete emerge as leading possibilities in Champlain Towers South tragedy
https://www.wsj.com/articles/behind-the-florida-condo-collapse-rampant-corner-cutting-11629816205

SURFSIDE, Fla.—A startling discovery awaited an engineer who drilled into the ground-level concrete slab at Champlain Towers South last year. He could find no waterproofing in two separate sections, the engineer wrote in a letter to the condominium board.

Without that essential layer for a high rise facing the punishing Atlantic Ocean, rainwater and salty sea spray likely had seeped in for decades, slowly weakening the steel rebar and concrete holding up the condo building. Indeed, the engineer reported at the time seeing significant concrete deterioration.

They skipped waterproofing in areas where saltwater could seep into concrete, the available evidence indicates. They put the building’s structural slabs on thin columns without the support of beams in some places. They installed too few of the special heavy walls that help keep buildings from toppling, engineers say, features that could have limited the extent of the collapse. And they appeared to have put too little concrete over rebar in some places and not enough rebar in others, design plans and photos of the rubble indicate.

The building should not have been certified.
Meanwhile in SAN FRANCISCO (AP) — A $100 million fix to stop a San Francisco luxury high-rise from sinking and tilting even more is on hold while engineers try to learn why the building has sunk another inch (2.5 centimeters) during the repair.
https://apnews.com/article/business-san-francisco-d44b9288019f08347294df72fb430e1a

The 58-story tower opened to fanfare in 2009 and all 419 apartments quickly sold out. High-profile residents have included former San Francisco 49er Joe Montana, late venture capitalist Tom Perkins and Giants outfielder Hunter Pence.

But by 2016, the https://www.seattletimes.com/nation-world/tilting-sinking-san-francisco-high-rise-raises-alarm/ (40 centimeters) into the soft soil and landfill of San Francisco’s dense financial district. It was also leaning, creating a 2-inch (5-cm) tilt at the base and a 6-inch (15-cm) lean at the top. Residents sued the developer and designers.

A confidential settlement reached last year with homeowners included $100 million to install 52 concrete, 140,000-pound (63,500-kilogram) piles to anchor the building to bedrock 250 feet (76 meters) below ground. Piles provide foundation support.

$100 M / 419 ~ $238,663.5 per apartment.

 

[artis]

Well the lesson here is simple, capitalism although much better than all the other tried out ways of human interaction needs strict oversight , without oversight the default mode is towards more profit and less safety.As for that San Francisco building , I read about it years ago, I think the stupidity there is simply that they should have understood that the soil and ground in that place is just not suited for heavy structures. Could have built a tower that is lower and lighter probably would had no problems.

 

[artis]

@Astronuc from your npr link I read that they suspect that the concrete might have been of a lesser quality than necessary.
Now again this is my own opinion not an official viewpoint but from what I know the color of concrete mixture once dried is a rather good sign of it's strength and especially it's adhesion, unless ofcourse a coloring additive or different mixture had been used. Normally the toughest and strongest type of concrete that I know is usually dark grey to even blueish in color, and what is most important it is like that throughout it's cross section not just at some spots. Generally the whiter the concrete tone the less cement it has and more additives.
I disagree that saltwater alone can make a dark grey to blue concrete white entirely. I have seen bridges older than 40 years that have endured extreme amount of road salt and water , ice and snow etc and yet their concrete is has not changed color drastically nor it shows any major discoloration.

What normally happens with concrete as it ages is called "concrete efflorescence" which is a whitish type of surface discoloration from various salts that come to surface as the concrete ages and also from atmosphere impact , like saltwater and moisture.
In the Champlain towers in every picture that you look, everywhere whether columns or floor slabs all the concrete is very white inside, and not just in spots but entirely throughout. I don't think this is due to saltwater moisture. You cannot get such even almost perfect color tone throughout from outside impacts.I can't say for certain about the Champlain tower case, maybe they just used a different mix/additives maybe even used coloring to make it whiter for better visuals can't tell without more info.

 

[russ_watters]

Well the lesson here is simple, capitalism although much better than all the other tried out ways of human interaction needs strict oversight , without oversight the default mode is towards more profit and less safety.

Since this is squarely in the realm of government oversight, I don't see how this has anything to do with capitalism.

If you are talking about developers cutting corners in general, that isn't a unique feature of capitalism either.