Engineers: 1 of 3 Columns Caused Miami Condo Collapse

[@38911bytefree]

This is the long way to prove how recillient buildings are even when designed at 50% and neglected for 40 years and all kinds of load added, filtration, salt... WOW .... I think this thing put a great fight against time that no one was willing to uncover ... for money reasons. As usual, 10/10 video, impressive effort.

[@jeffostroff]

Thanks, I'm glad you liked it!

[@major__kong]

If it makes you feel better, people staring at large cracks and not thinking there's a problem isn't limited to buildings. A passenger on Aloha Airlines flight 243 noticed a crack in the skin near the door as they were boarding. A large piece of the top of the fuselage peeled off on that flight. Luckily, only one person was killed.

[@jeffostroff]

Yes I remember that accident, way back in time

[@ChipsTheOrigamiLemon]

That’s crazy! You couldn’t pay me to go on an airplane with visible cracks.

[@scvcebc]

At the Honolulu Airport, there is a memorial plaque for the flight attendant who was sucked out.

[@chipbug]

If not for the heroic efforts by the 2 pilots, the plane could have crashed. A lot of the experts amused how they managed to get the plane safely back to the airport.

[@scvcebc]

@@chipbug They did not return back to Hilo, they were on the way to Oahu, but detoured to Maui and landed there.

[@artistjoh]

We can see revisions of the original plan on Champlain Towers South. What I would like to know is - are there similar revisions at the still standing Champlain Tower North? Has there been any additions to the pool deck like at the South tower? This is the sort of question I would want answered if I lived at Champlain Tower North.

[@rcsontag]

It is obvious that the pool deck partly collapsed due to the "punch through" of the support columns. The problem with the whole scenario is why in the world would the building structure be dependent upon the stability of the pool deck? These two structures should be independent neighbors.

[@jeffostroff]

The design was dependent upon itself, but fell victim to the deck collapsing.

[@jblaze0382nj]

Idk about anyone else in this comment section but, damn i get excited to see Jeff drop a new one every time!

[@jeffostroff]

It is fulfilling to finally upload each video

[@jblaze0382nj]

@@jeffostroff ty for your hard work as usual. That Google map overlay put things in a clear perspective. Great job!

[@lookforitcx]

Always a treat to see Jeff has uploaded a new video on CTS. Brilliantly researched and compiled. I find it so informative and when it ends after 22 minutes, I watch it again 😊 Keep up the good work Jeff. We appreciate you.

[@richardross7219]

Interesting but, until owners and managers go to jail for long stretches, very little will change. Maybe an inspector or two were responsible too. A good engineer should be suspicious of everything. Good Luck, Rick

[@williamhaynes7089]

some owners and managers died in the building colpase... as this was a condo not an apartment complex.

[@Davemak4944]

Thanks for keeping us updated, Jeff! Excellent analysis as always.

[@jeffostroff]

My pleasure!

[@itsraining6449]

And his voice is very relaxing to listen to.

[@moxievintage1390]

This was fascinating. The visuals really helped. I had seen videos mentioning the overall last minute change per se…but hadn’t heard about significant discrepancies in spacing. I decided on L11.1 quite early ~ What a terrifying ordeal…and as Juan Brown says about aviation accidents, “always a teachable moment”… Hey definitely enjoyed your work on Titan, too-the communication transcripts were incredible! Just thinking about how those last few minutes all went down is such a mind trip!!

[@jeffostroff]

Yes, can't wait to see the final report on Titan!

[@shrodingerschat2258]

Don't forget the broken support column recently on that roller coaster at Carrowinds.

[@gonavy1]

Jeff i love following you and listening to you explain everything but would it be possible to turn off the background music. It just makes it difficult at least for me to hear you talk. Thanks and i look forward to the next video

[@williamhaynes7089]

Strange, i didnt really notice the music... could hear him well

[@patrickmorrissey2271]

Great job. You raise a really great and key question at the end.... If all of the columns were exceeded..... Uhhhh.... Why wasn't shoring ordered???? Why wasn't further testing performed on more columns???? Or, did the board say no, that's enough, we're not paying for any more testing???? Is it taboo to ask that question, now that many participants are no longer with us????? Maybe I'm wrong, and I know, all the cases have settled out, but.... There are some big questions here, about public safety.....

[@jeffostroff]

yes shoring should have been ordered as it was in CTN

[@thoughtful_criticiser]

As for rebar being too deep, I was watching a slab being poured in London last week, the rebar was carefully laid out and spaced. On the day of the pour the crew were walking on the rebar as they poured. In the places not yet poured the rebar was no longer spaced as intended. Instead of being spaced vertically, the rebar looked as if it had been placed directly on to the previous member. The change in size of the tributaries on the south side of the pool deck could be justified if the engineers designed it just to support the slab and people using the pool with loungers and patio tables. Never intending it to support planters or machinery.

[@leeroberts1192]

I don't know if any engineering issues outside of the US are of interest to you but here in the UK atm there's big issues with the safety of buildings that have used reinforced autoclaved aerated concrete. It's caused I believe at least 100 schools to partially or fully close and some hospitals have got issues with it as well

[@colleent610]

Looks like someone was cutting corners.

[@jeffostroff]

Add in some lack of design check and you have a recipe for disaster

[@jmatx]

"Look here" Where? "and here" Where? "here you can see..." Where? "and over here" Where? Please use a large, obvious, colorized cursor.

[@heartoftherobot]

I’m not an engineer but I do have construction background and to me, it seems like it should be common practice for the building to be broken from the pool deck in the same way a bridge deck is broken from the ground on an interstate. It looks like a failure of the pool deck area occurred because they thought it wouldn’t ever see the loads for it to collapse. You ofc don’t design for a collapse, but it seems like this shouldn’t have bright down the whole building. So sad

[@markn8866]

The “J”s win - Jeff and Josh are the BEST!!! Much appreciate your research, analysis, and insights.

[@jeffostroff]

Us Js gotta stick together!

[@clouddancerss]

Wow, thank you for another fantastic video Jeff! I love the way you use overlays and photos to reinforce what you’re saying, and make it easier for those of us who are not engineers, to understand.

[@jeffostroff]

Thanks have many more to come

[@hayleyqueen987]

Hey Jeff, love your work 👍. I think the smoking gun is the “white vehicle” sitting in your picture next to 13.1. The engineer hasn’t allowed for, not only the weight of the planters, but also the “Live” loads of the cars next to that area. This combined with the extra weight of the sand, tiles, palm trees, heavy machinery, and the offset and longer span from 13.1 to the columns to the south (to allow the car park level to work better😐) all combined to the calapse of the deck and then pull the building with it 😕.

[@MajorCaliber]

Kids!... if you're in ANY Reiber-developed tower (CT North, CT East, Mirage on the Ocean, etc.) and you hear strange creaking noises... *quick, JUMP IN THE POOL!* ... it's the only safe place.

[@jeffostroff]

Yes that pool held up nicely during the collapse.

[@360alaska6]

I'm not an engineer, but I can't understand why they would design the building to depend on the pool deck structure for support. That would be like building a house that is dependent on a backyard deck for support, it makes no sense.

[@jeffostroff]

the columns and the beams support the building, but they did not expect that the collapsing pool deck could rip out beams that would then pull on columns holding up the building.

[@Seashellsbytheseashore21]

@@jeffostroffthey didn’t realize the rug was going to be pulled out from under them, you could say. Sad

[@360alaska6]

@@jeffostroff I guess to clarify my comment, why were they coupled at all?

[@waitaminute2015]

​@@360alaska6I'm perplexed about that too.

[@jakeo.]

Jeff, I have found your videos on the subject to be very interesting, and that made me a subscriber. Two things to throw out for consideration, though: 1) there is very faint music in the background that I find distracting, and 2) the comedy clips and movie clips that you throw in are totally unnecessary and detract from your presentation. The subject matter and your intelligent analysis speak for themselves. Get rid of the music and the comedy.

[@Daniel-it1dp]

This whole deal just goes to show how dangerous cheap renovators can be not knowing or considering anything about physics and engineering. They use laborers that just do what they are told with minimal direction and oversight so I really blame the owners of these companies. Too many keep on doing these things because “it’s never been a problem” but it’s more of they’ve just gotten lucky. It also goes to show the laborers setting up the rebar and laying the concrete are not engineers and we’re not properly having their work verified and checked by a foreman with the design specs. So many compounding errors and deficiencies.

[@firewalker1372]

Why did they get rid of the step down? Maybe to save money? Seems there has been a few corners cut when this structure was built. Why was the column type changed, at the end of the day I think it all boils down to money. Hell I could be wrong though 😂. Love the series man, keep up the great work.

[@jeffostroff]

Thanks for continuing to watch

[@tretre1692]

I wish I was dedicated enough to be an engineer.. back then, I hated math. Now I’m excited to help my daughter understand math in a way where she finds it fun and exciting where she can find a career like that!

[@fromaggiovagiola9128]

I wonder if any of the Engineers had a Stocton Rush Toupee hairstyle. Don't trust any Man hiding baldness.

[@bob456fk6]

Especially if he wants to be President of the United States.

[@jeffostroff]

They are all dead now, architect and engineer

[@hopefultraveller1]

Thanks again, Jeff - revealing and most thought-provoking.

[@jeffostroff]

Thanks, I'm glad you liked it!

[@rustybeatty6567]

All the added weight of all the marble and granite added to the inside of the building and also the penthouse floor lead to the whole building collapsing in the first place because it was that part of the building that failed and collapsed into the pool deck area and into the underground parking area. That building should have never have had underground parking in the first place that close to the coastline. Salt water is like acid to concrete and steel rebar.

[@messupfreq550]

Gotta believe 9" of sand, if waterlogged (likely?), must weigh as much as the original load. Don't see how the sand would ever dry out and capillary action would make it "thirsty." Place planters on top of it just made the load worse which the column punch through make evident. Besides any original design deficiencies, the "renovation" adding all that material to the deck added enormous stress as you pointed out.

[@redsquirrelftw]

The fact that they added a new layer of pavers with more sand makes me wonder if it was actually very slowly sinking over time, and water was pooling, so they did this to build it up and slope it, but added a bunch more weight and just made the problem worse.

[@jasons8479]

It's not just the immense weight of those added palm trees, it's also the deflection from them blowing around in strong coastal winds and storms. The trees themselves might not appear to move around that much, but that force has to go somewhere. Likely causing cracking and allowing water intrusion causing rebar corrosion.

[@robertfraser5994]

At the 13:55 mark in this video is a still shot of the pool area after the collapse. You can see a double vertical row of blue tiles around the pool. The bottom row is likely the original height and the tiles are a slightly different shade than the tiles in the row above. The bottom row of tiles would originally have had pavers on top of it. A double row of tiles is unusual and you can tell it is not original because to emerge from the pool, a user would have to lift their feet unusually high from the top plastered step to the height of the added paver deck. I'll bet that the skimmer/scupper reservoirs were never raised from their original height, so they would have been at the original height and a pool guy would have had to reach unusually far down to grab the leaf basket. On second thought, behind the top row of pool tiles, they may have poured a concrete wall on top of the pool's bond beam and attached the tiles to it. Or alternatively, they might have laid a row of some kind of masonry blocks. You have probably collected every publicly available photo of the collapse site, so you may know the answers to some of these questions by mentally reviewing what you have seen. Could the motivation for adding so much height to the entire paver deck have been to eliminate the "step" shown on the original architectural plans which ran from south to north on the west side of the patio area? And could this mean that the underlying structural beams shown on the original plan that were part of that step were present, but the step's presence was masked by the added height of the setting sand and pavers? If this was the case, the added weight would have extended to the pony wall along the north side of the patio area. Keep in mind that sand weighs 1.3 to 1.6 tons per cubic yard. As you say, the original plans would not have anticipated this extreme added load. I wonder if there are photos of the walkway at the northeast end of the patio and whether there is evidence of added height where it tied in with the original surrounding walkway. One question that needs to be answered is exactly when all that extra sand was added on top of the patio's concrete, and who made the decision. Was it during the original construction of the patio? It seems doubtful, or there would not be two rows of pool tiles of what appear to be different shades. The water level in the pool may have been raised by 9" if that is the height of the added setting sand. The weight of this water would not have been factored into the original plans, but fortunately, the pool was probably supported by soil underneath it, given that it was beyond the basement's footprint and therefore did not collapse. Remember that some of the patio pavers tiles/pavers near the north planters were removed (by an engineering firm, I believe) in order to evaluate the underlying structure. The tiles were never replaced, as I recall. But I had the impression that there was exposed concrete (or something similar) in that unprotected area, not a 9" layer of setting sand.

[@jeffostroff]

The pool was never an issue in this collapse not even a factor because the pool actually sits on top of the garage floor and the walls of the pool are built up from there so no amount of water in there is going to have any kind of effect on loads. However those layers of paver bricks that we saw do have effect on the loading because they are weighing down on the concrete pool deck slab

[@LakeNipissing]

From the beginning, you always suspected the column 27/28, Jeff. When you walked the perimeter of the property and took several high resolution photos, there wasn't even a stump left from that same column.

[@jeffostroff]

NIST dug up 3 of these columns, so they are looking at them as suspect also

[@dougc190]

I'm sure this is already been said, but I remember one of the Josh Porter videos he had done the math from the plans and ascertained that the pool deck the way it was originally in the plans was already at capacity just the way it set. So we're not counting people 9in of sand in places none of that it was overweight from the beginning.

[@matthewmosier8439]

I'm shocked at what was done on/ to the pool deck before the collapse. Machines, sand and pavers, etc. I've been in construction for years and am suprised that none of the wealthy men or women who lived in the building had experience with construction or a related field such as engineering and put a stop to it. As soon as a person learned that the pool deck was sitting on small columns, I would have assumed that they would raise an alarm at seeing all the weight that was placed on that area, and the photo from shortly before showing the planter with the cracks and gap growing at the deck face should have also been a huge red flag.

[@chipbug]

It is sad how badly designed this building was. However, it was even sadder when there were many opportunities that they could have noticed and fixed the issues, but 'experts' didn't do their proper job.

[@jasons8479]

Or the condo owners association preferred to spend money on fancy lobby upgrades.

[@keithpeacock9282]

Stainless steel rebar would solve the rusty rebar problem when your only 200' from the SALT WATER!

[@jeffostroff]

also epoxy coated rebar, but they appear to think corrosion was not so much a factor, as was the bad design of the building

[@jimmiller5600]

What failed? Collapsed? Design, Permitting, Construction & Inspection, State regulation and finally the residents themselves consistently voting "we refuse to pay for maintenance".

[@guruofendtimes819]

You are correct about the long spans but the calced LL and DL were just for a pool deck.The step beam was 12" less deep than originally designed for. The pool deck was raised 12". Other problems were lack of shearheads at columns, lack of shearwalls, Poor bond stress and concrete quality. In addition to a weight room and trees on patio.

[@newcarpathia9422]

The trouble with trying to ascertain where this started is defining "started." One column fails a bit, which causes another to shift, which causes another to shift, which causes the wall to give a little, back to the first column... On and on over years, until one of them finally had a "dramatic moment" which makes everything else progress rapidly. Shall I surmise that by "started," we are looking for the "dramatic moment?" Would the dramatic moment whatever caused the pool deck to start sagging or would we go more dramatic and fast forward to the night of the collapse?

[@Sylvan_dB]

I'm a software guy, and we have similar problems in my industry with people adding layers and building/changing without understanding what is going on underneath them. It's partially willful ignorance, yet also a necessary coping skill - everything has become so complex and so rushed that there is no time for the people involved to dig in and learn everything all the way down and sometimes it is actually impossible because the lower layers are inaccessible. At some point we *all* rely on the work of others with the expectation that it was done correctly.

[@mjookie]

Does it make any difference that the columns south of K13.1 are not just wider spaced but also offset? Your videos are endlessly fascinating - these days I look rather harder at construction methods! Thank you

[@wacojones8062]

I smell a possible criminal charge in the future. Columns undersize, erratic spacing, pool deck slabs to thin and way to much weight added, pool deck should have had a physical separation from the rest of the structure.

[@hayleyqueen987]

L🌙VE your work Jeff, best channel along with Josh at Building Integrity ❤ very good analysis 👍🙏

[@rufkutdiamnd]

@jeffostroff honestly I’m not so sure about that column failing first since Cassondra couldn’t see around the corner of the building next to the lobby/pool deck. Her condo was tucked in but she could see the area where the Nirs lived

[@chaseman113]

Based on your comments on column spacing, it almost looks like the engineer wrote themselves into a corner after loosing 15% of their column budget in a poker game.

[@jeffostroff]

es good analogy

[@shrodingerschat2258]

The long and short of it all is that this building should have been condemned years prior. Instead shortcuts were taken, and I'm sure inspectors were paid off by property management since that was probably the cheaper alternative than spending the money to make the repairs needed to make the building sound. This also makes me unwilling to set foot anywhere near a concrete column/beam/slab building.

[@mariemccann5895]

Excellent work as ever Jeff, but what is with he background music, it is a bit distracting, personally it is better without it.

[@ronarant2897]

I think whoever was paying the bill didn’t want to know what or how much was wrong. The bean counters will spend as little as they can get away with. It always seems to come down to money!

[@additudeobx]

Thanks Jeff, once again, for the outstanding effort. For all it is worth, its fallacy is that it takes decades for buildings improperly constructed to render and manifest themselves. You stated and pointed out early in the diagnosis how the planter's weight and pool deck resurfacing were contributors to the collapse.

[@buckwilson4167]

Super helpful visuals in this vid especially at 20:25 showing exactly how it was collapsing over time.

[@ccdoe2441]

Are building plans of condominiums public? Where can I find building plans and design drawings?

[@SuperMarkizas]

You put so much work into this! Most appreciated!

[@RealButcher]

Wo... even more new investigating things... thanks. This stays a very important thing to talk about. Because of more buildings of that time at that place, next to saltwater. ❤ And the same type of engenering and costcuttingcorner-stuff. 😮

[@billiamc1969]

What I don't understand is why folks don't realize that American construction is not about building safe structures...it is about building as fast as possible to the lowest cheapest standards possible to make as much profit then flee the state

[@fillmiller780]

could the larger spacing of poles be due to the lighter load requirements of the pool deck?

[@jeffostroff]

yes, but also why did the rest of the pool deck have shorter distances?

[@fillmiller780]

​ @jeffostroff I don't know, but I'd think that the load from the condos isn't "straight down", and that dynamic conditions (short interval like hurricanes and long interval like soil settling) would mean that you have to add more load-bearing capability closer to the condos. I'd be most interested to learn what changed in the design that led to the omission of structures between 79 and 80...why did they think the load would be less?

[@hu5116]

Hi Jeff great vid! However, it might be worthwhile to explain why rebar set deeper into the concrete is bad. I am hypothesizing it due to tensile leverage (my terms) again the load lever arm, but I’m not sure that is right and I’ll bet others are not clear why deep rebar is bad also. Thx!

[@mightymouseofnyc]

The engineering company who designed this tower should be investigated to include all the buildings they designed.

[@susanKWithAnE]

Does the Design to Capacity Ratio include time? Does time have an impact or is that calculated another way?

[@billj5645]

Having removed some of the beams and the stepdown would actually result in a stronger system because the stepdown and beam-A didn't have enough strength to do what they needed to do. Ironically the original design would have likely saved a lot of lives because it would have collapsed during construction rather than 40 years later. The additional tributary area that you point out will increase loads on the adjacent columns, increasing load on the punching shear zone at the same columns. It also creates unbalanced moments that aggravate the punching shear problem. I believe NIST also pointed out deficiencies in flexural steel in the longer spans. How would the original engineer know they would add the additional sand and pavers? They would know that this is the way buildings like that are always constructed! If they didn't know that and they didn't design for it, that is negligence. I've been designing them for over 40 years and have always allowed for additional sand, concrete and pavers. Sometimes there is a lot more than 9" of additional stuff, I've seen structures with over 3 feet of sand, concrete and pavers. Consider at Champlain Towers the floors inside the residential tower are 18" higher up than the slabs in the pool deck. You have to have some way to make up that difference so you don't have to have steps and ADA ramps at every exterior door so you do that by building up sand, concrete and pavers. You also need to provide slopes in the pavers so that they will drain off rainwater so you build the slopes into the sand, concrete and pavers instead of in the structure itself. The coefficient of 4 in the punching shear equation has been in the code since the beginning of time, since the first time that equation showed up in the code, and is still in the latest version of the building code. The equations have never considered the amount of reinforcing steel and if the slab had been designed and reinforced properly for the spans and loads involved there would not be any discussion of low reinforcement ratios. There may be some research being done on punching shear capacity relative to low reinforcement ratios but you will find very few engineers that know about this or use it.

[@TheHandyHam73]

In 2018, Morabito cut an inspection hole in the basement slab to examine the sub-basement area around the pile caps and in fact the Recertification plans included concrete beams installed in the sub-basement area reinforcing pile caps.

[@user-pf5xq3lq8i]

Exactly. NIST puts us off the trail- building was falling down, most people knew it, construction was planned. Owners and city hall let the 40 year guarantee expire *without an evacuation order*. The builder, however bad, said it would last 40 years..and it did.

[@WhittyPics]

Your analysis is right up there with Josh Porter's. Don't the columns under the building need to be closer together to support the weight of the building?

[@jeffostroff]

The columns under the building were likely sized appropriately to handle the extra load they were 16 inch by 16 inch, whereas the columns under the pool deck were 16 inch by 12 inch. But then the niche that NIST has found is that they think there was overcrowding of the rebar in many of the columns which would make them weaker so that they wouldn't even support the weight they were designed to support.

[@Dana_Danarosana]

Wow! Seeing all this, the elephant in the room would now be CTN, right?

[@dminner]

Parking spaces = Condo Sales (Greed overruled common sense).

[@hines862009]

22 minute video seemed like only 2 minutes ...excellent presentation!

[@kathys53]

Wonder what's up with Champlain Towers North these days.

[@leagarner3675]

Love that overlay!

[@jeffostroff]

I am so glad you liked it I worked on it for a couple of hours to get it right

[@MajorCaliber]

El Jefe, WHAT is the latest on... _drum roll_ *The Mystery Column* under the massive H-beam, and (seemingly) right in the middle of the driveway??? 🤔 🧐

[@jeffostroff]

They have not mentioned that column at all. Only thing I can think of is that it was not in original plans, but was likely in the as-built plans. This does happen in construction, which s why it is so important to save all the plans

[@jamesbehrje4279]

It rained really hard that week. All that water inside the sand of that pooldeck was a death sentence for Champagn Towers!!!

[@jeffostroff]

Just think how many times over the years since 1996 when that pool deck was rebuilt, how often it rained and saturated that water and probably takes days to fully evaporate under all of those paver bricks inside 9 inches of sand. Imagine that weight coming and going over the years in making that pulled deck go up and down like a trampoline

[@jasons8479]

Plus all the salt from the adjacent ocean, tracked in by foot and by winds. Which would not evaporate, but rather percolate through the failed waterproofing, causing rebar corrosion.

[@PotooBurd]

This is so informative!!! Fantastic video; I love this kind of content!🌻🌼🐝

[@jeffostroff]

Thanks so much!

[@orionbroadcast9226]

My apartment buildings (build just after WW2) have stair wells that are not part of the load bearing structure, meaning if they fall down, the building wont collapse. However, they sure don't look safe. I call it the scare case. The sides of the slab are all cracked, 1/2 to 2 inch thick pieced have come down from the ceiling. I am glad to be on the 1st floor where I only have to dash under them for a split second rather then use them to access my apartment. I was on the second floor visiting a neighbor recently and noticed you can see some of the rebar showing through the floor meaning that at least some of the rebar was at the top of the slab. There is supposed to be inspections of this complex annually, yet this stair well has been in this condition for years. Is there anything I can do that's no going to get me forced to move?

[@jeffostroff]

It should be reported to somebody at the city. To come take a look at it because that is very dangerous at this point.

[@alro2434]

Great job, THANKS! Surprised that rebar should be at the top part of a slab, isn't that in compression, & concrete's strength, and tension on the bottom with no rebar, concrete's weakest usage?

[@jeffostroff]

there are usually upper and lower rebar

[@larrysiebens5170]

Nice update Jeff, as I chatted long ago, being a paving stone installer and builder for many years.......the added weight of the overlay was the cause.. 3000 lbs per pallet and a 3 ton machine moving on the concrete deck = failure......cool update :) !!

[@moxievintage1390]

That was crazy to see that weight!!!

[@TheHandyHam73]

Did these changes take place before or after the Crane collapsed on several pile caps early in the construction?

[@jeffostroff]

Good question we don't know if crane collapse shifted naything.

[@shAnn0n1]

The video from the couple across the street from the driveway of Champlain Towers, and the woman on the phone with her husband saying "the pool deck collapsed" were absolutely right about what they saw. Jeff, you were absolutely right too about the remodeling and the extra weight, the load, and now we know that the building was collapsing slowly for years. Great breakdown Jeff.

[@kierannorris2283]

It looks to me like that extra spacing in the last row of columns was in regards to to pool and the area it took up. There was only the pergola/tent thing over that area so I don’t believe there was a problem with that section being overloaded. The extra sand and pavers added on later.. maybe. But from original design I don’t believe it was unreasonable. The pool had all that extra support under it so no extra stresses there either

[@kierannorris2283]

That being said, I still believe a huge part of the cause is the extra weight from the added sand and pavers. But again, based on original design Calculated with expected loads I don’t believe that spacing was an issue

[@katzfam1089]

Seems like many years of incompetence, every time they did a Reno things got worse. Didn’t they know the spacing of the columns were to far apart, didn’t they have the brains to see when every column showed overstress to fix the issue? I am by no means an engineer but I was a home builder and this reeks of cost cutting, cheap under experienced contractors and poor inspections and execution by the inspectors to fix all issues each and every time.

[@jeffostroff]

I hope these lessons learned will be taught to all maintenance companies, and boards of directors

[@gtaelement137]

Hello Jeff thank you for the update 👍👍👍

[@jeffostroff]

No problem 👍

[@katzfam1089]

Is it possible to take X-rays of columns to identify the depth of the rebar in each coloumn, or is that just a weird thing I’m thinking about?

[@jeffostroff]

They did that with sonar I beleive

[@youregonnaattackthem]

Phenomenal overlay with the transparent layers.

[@jeffostroff]

Thanks, I'm glad you liked it!

[@d.t.4523]

Thank you. Keep working, good luck.

[@loufuddrucker391]

Thanks for keeping this active.🎉

[@cynvision]

Bad contractor decisions to resurface the deck which was designed for a lighter dead load. Where was their structural engineer?

[@cynvision]

Sort of wondering if Moribito ran out of time to extract themselves from a project they could not afford to take the risk on once they did some back of envelope calculations on the other columns.

[@johnzee691]

the more info that comes out, the scarier it appears. the buildings engineering, the location in regards to salt water, shear factors ( not sure if this has ever been talked about or if its factored in) of weather events such as hurricanes and other storms really put life span on these buildings. and to think how many other buildings are ticking time bombs.. and now with ecars, and the weight differences. tick tock..

[@rubyoro0]

Couldn’t click fast enough!

[@jeffostroff]

Glad you finally clicked!

[@MCC876]

Jeff, is there common acceptance of how to classify if a condo is new, middle-aged, or old?

[@jeffostroff]

No standards that I know of, but they do have a 30 year recertification inspection now, and it is 20 years if you are close tot he ocean

[@dustyflair]

HOA money went to everything BUT upkeep up the building. Trypical

[@jeffostroff]

We see it a lot here in FL

[@ApartmentMaintenance]

Great video Jeff! 💪

[@jeffostroff]

More to come!

[@bebyntvbebyntv5165]

What does this mean for the north tower?

[@jeffostroff]

CTN Tower has several benefits that the South tower does not have, for example north tower years ago had all of the owners removed their tiles from the patios. Also there's two less units per floor so the building weighs less. The north tower did not have as many planters as the South tower did and never had the excess weight of the palm trees. The north tower kept up on their maintenance and although they did have some problems they were proactive in bringing in shoring poles and are in the middle now of repairing all of their patios, and they are under the care of Allyn Kilsheimer which is a very well known and respected structural engineer

[@The0125johnny]

What does this mean for the sister towers ?

[@jeffostroff]

They are already investigating Champlain towers North, and it was built years later different contractors, not so many planters, no palm trees on deck, and they are bolstering columns and patios now

[@billj5645]

They have never made final drawings available for the north building. It has a similar layout but could have been designed by a different engineer, could have different reinforcing, etc.

[@pomonabill220]

Love these analysis that you have presented and what Building Integrity presents. VERY thorough analysis and great illustrations that show what went on! Thank you for all your work on this. Very interesting.

[@chrismullins3645]

With respect.. At some point the car park was full.. So they parked cars on the pool deck.. Which was never designed to hold that weight.. Look at the lack of rebar sticking out the column's.. Look at the initial plans.. God Bless..

[@elantrauma]

Where did you get the blueprints for this Jeff. I'm entertaining the idea of making a physics simulation in Unreal Engine 5?

[@billj5645]

Right after the collapse they were available for download from the city's website.

[@jeffostroff]

It was on surfside web site.

[@elantrauma]

@@billj5645 Did they take them down? Do you have a like?

[@elantrauma]

@@jeffostroff Do you have a link?

[@wendymontie5660]

The weight of the palms contributed. PLUS what do palm trees do? SWAY. What happens on the seaside? Winds, fairly constant winds. The weight of the palms, plus the harmonics of the movement contributed. Had they stuck to shrubs in the planters, the building may have lasted longer…still would have collapsed given the second bit of bedding & concrete pavers. Did the condo association get a structural inspection done before adding the second set?! Probably not. That costs money and wouldn’t make the ‘beautification’ project be able to happen.

[@ryanlansom7951]

Love the videos Jeff. I reckon you should look at that footage of unit 711 in Champlain towers south there’s a crack going down the wall before the camera shut off. What happened to that video you made about NIST getting the footage of the building collapse from 87 park it had high resolution.

[@OpenRoader]

What is happening with the sister building?

[@hitomiratel7349]

Ahh, those pesky engineering relation factors! Usually arrived at from simplified stress field equations, one can argue forever if 4 or 3 is proper but a detailed FEA will give you much better values for the specific geometry and loading. I know, if it's all you have to go on it's better than nothing but I think it was a little deceptive to use the factor that "got rid of the problem" without being too obvious (like using half the usual). Great to point out that little bit Jeff!

[@Sylvan_dB]

Sounds like NIST and WJE both posit that engineering design was flawed, and the construction was in error, and the maintenance/upgrades over time exacerbated the flaws in design and construction, and then maintenance and warning signs were ignored. In other words, everybody thru the history of the building is at fault.

[@sunshinecindy570]

Nice work Jeff! Very interesting! 👍🏼👍🏼👍🏼👍🏼👍🏼

[@jeffostroff]

Thanks 👍

[@amunderdog]

Good observations of the column spacing. i remember? eye witness reports were K13.1 failed first. Then a period of time before the rest. You overlooked the designed drainage of the deck, being deleted by the added materials.

[@garyc39]

The structural engineer and Building inspector did not do their job.Was anyone charged with manslaughter.Did the building inspector make sure the rebar was spaced properly before the pour.Did the concrete have the right amount of aggregate to cement called for.Why were the tenants allowed to put heavy objects in their condos.A whole bunch of little problems make a big problem and the building came down.