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

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04
Miami Beach, Champlain Towers South apartment building collapse, Part 05
Miami Beach, Champlain Towers South apartment building collapse, Part 06
Miami Beach, Champlain Towers South apartment building collapse, Part 07
Miami Beach, Champlain Towers South apartment building collapse, Part 08
Miami Beach, Champlain Towers South apartment building collapse, Part 09
Miami Beach, Champlain Towers South apartment building collapse, Part 10
Miami Beach, Champlain Towers South apartment building collapse, Part 11
Miami Beach, Champlain Towers South apartment building collapse, Part 12
Miami Beach, Champlain Towers South apartment building collapse, Part 13
Miami Beach, Champlain Towers South apartment building collapse, Part 14

SF Charlie
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[Demented]

Maybe that's why stuff in Florida, south FL in particular gets messed up so much down here.

Got your degree with straight c's?
Have at least some "experience" on your resume?

HERE'S YOUR PE LICENSE GOOD SIR. BETTER CARRY GOOD INSURANCE.

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

 

[AusG]

I'm puzzled as to why the vertical load capacity - or otherwise - of the south wall is suddenly a thing. The point, and I have been paying attention down the back here, is the sag of the deck and heavy planters creating a catenary force on the load-bearing columns and/or load-transferring beams in that critical KLM area of the building, with the collapse of the deck imparting a rotation and loss of support to those structural elements and pulling the rug out from under. If the deck letting go laterally from the south wall can be shown to contribute meaningfully to that story so be it. If it would make little difference, ok, bang goes that component. But in no case does anything in the working hypothesis depend on building load appearing at the south wall. That would be ridiculous and no-one is promoting it.

 

[spsalso]

AusG,

It started with the concept that the construction to the south could have been at least contributory to the collapse. And if it did, the "entry" would have been at the south wall.

The discussion entered into the area where the deck and the vertical wall of the garage meet, and the purpose and type of the connection. And the failure in this area. This included such things as the scrapes on the wall caused by the broken rebar as it fell.

My contribution was speculating that that area failed from west to east as the parking area/planter went down, falling first.

I think others might have speculated that the fail DID start at the pool deck garage wall interface, caused by damage by the southern construction. I believe there is a lawsuit that asserts something like that.


spsalso

 

[Optical98]

I find the discussion of the wall being load bearing or not interesting. It may have had something to do with the pool deck collapsing.

However, the pool deck collapse did not bring down that building.

From the sequence of events it has been made clear that the Nirs and Security heard sounds from above, the Nirs hearing this for at least an hour prior to the collapse and unit 1211 hearing sounds the night prior.

Mrs Nir heard what sounded like a wall falling into hers Before the pool deck and the parking deck fell.

We have to look closer at the Above sounds and the shear wall.

Spalso, the west to east fracturing also goes along with what Nir's son said about it feeling like a collapsing card table. The rebar pulling from the shear wall, I'd say may have started several floors above which coin sides with the blocks falling into the elevator shaft.

 

[IanCA]

Hello,
I have been closely watching the information being released about this collapse since it occurred, and also working to understand and communicate some of the potential risk factors, but I only started paying attention to the information being posted here a couple of weeks ago. It has taken me that long to read all of the previous posts and take notes on the information I found to be most credible. I am very grateful to everyone who has contributed their time, knowledge, imagination, creativity and dedication to understanding the causes.

what supports that wall? I'm talking foundation what carries the load? It there was a grade beam over piles piers or even a footers then that would be one thing, but there is nothing under that wall.

Keith, please refer to the section detail of the perimeter wall posted by structuralex in part 02 on 30 Jun 21 14:22 it clearly shows the structural support.

If the deck letting go laterally from the south wall can be shown to contribute meaningfully to that story so be it

If the vertical support provided by the southern wall is removed, the guest parking deck area is essentially supported in cantilever only by a single column, I14.1, with partial support by column 14.1 G.1 and column 15 J.1 (actually located between J and K but not explicitly identified on S4 of14). I'm quite confident that calculations will show that even under optimal construction and maintenance conditions, the design strength of the column slab detail at I14.1 would insufficient to support that load and the associated bending moment. The problem is that the column is only 2 feet square and the load is effectively being applied more than 20 feet away.

However, the pool deck collapsed did not bring down that building. From the sequence of events it has been made clear that the Nirs and Security sounds heard from above,

That is only part of the story and relies on their perception of the direction of the sound source being correct. The sequence (thanks very much for the timeline MaudSTL) includes descriptions of "cars jutting out" at ~1:15, reports of the pool deck collapse at >1:17, both events before the building collapses. The problem with accurately understanding the direction of the sound is that people are very accustomed to hearing noise from above due to occupants in the appartment above, but much less frequently from below (requiring someone to be banging on the ceiling of the garage). Also with structure bourne noise the sound is propagating from surfaces of the room so the surface finishes have a strong influence over the relative levels, carpet will reduce the apparent level from below. Direct sound propagating through the front windows is likely to bounce off the ceiling.

Alternatively they could have just built that South wall so the edge of the pool deck rests on top of it rather than tie into it.

Jeff, The parking deck was resting on top of the South wall after rebar failed. The single row of vertical rebar at the wall slab connection was forced to work as a hinge to accomodate the thermal expansion and contraction of the deck and was alo exposed to the highest level of salt and chloride concentration. The constraint of the deck was far more stiff at the north side where the building was.

 

[Keith_1]

I just don't have time to check this every day.

I do agree that if the Beams were weekend of course the slab was, but they serve two totally different purposes. If this were a localized point of failure that was not at grade or subgrade, and resulted in this type of failure it would raise questions, but not very difficult ones, in the context of a 40 year old building.

The biggest issue that that has ever occured in terms of decks occured with post-tensioned system widely used in the 1970's that was a trifecta of really poor metallurgy, design and installation detail, especially with the bonded tendons. This was a real and 100% defect in a construction product, and trust me not a single architect, engineer or contractor would have ever intentionally used such a product in construction. I would like to say that there was no failure that. like chapman resulted in the loss of life, but there were, especially in Northern Parking structures. Once the problem was known and understood, the building professions remediated alot structures, that to this day, and for many decades into the future, will be strutrualy sound and safe.
I just don't have time to check this every day.

I do agree that if the Beams were weekend of course the slab was, but they serve two totally different purposes. If this was a localized point of failure that was not at grade or subgrade, and resulted in this type of failure it would be a real head scratcher.

The biggest issue that that has ever occurred in terms of decks occurred with post-tensioned system widely used in the 1970's that was a trifecta of really poor metallurgy, design and installation detail, especially with the bonded tendons. This was a real and 100% defect in a construction product, and trust me not a single architect, engineer or contractor would have ever intentionally used such a product in construction. I would like to say that there was no failure that. like chapman resulted in the loss of life, but there were, especially in Northern Parking structures. Once the problem was known and understood, the building professions remediated a lot structures, that to this day, and for many decades into the future, will be structurally sound and safe.

The above is actually a real long term defect in construction that took years to be understood, there was no nefarious intent and I think every engineer that was involved in designing that system was haunted by their mistakes.

The Miami bridge collapse is different, in that instance I actually place the blame on everyone involved -- especially the field engineer that tensioned or de-tensioned those cables. Hell, I blame the super and project manager for not vacating the deck, stopping traffic and not calling the fire department. They actually should have known better, so put them all in jail. I would never work on a tendon with anyone standing over it, under it, or within a hundred feet in front of it. If you are stressing a tendon and someone gets injured or killed it is your fault, and in my opinion should be criminally responsible. Side, note -- I had one fail in my life, it tore up 8 feet of concrete and embedded itself halfway into an 8" concrete wall that was 80' feet away, no one got hurt because I controlled the environment around me.

Chapman, failed because unfortunately professionals are simply not involved post construction, because frankly we find dealing with a bunch of idiots taxing and not worth the time. If Chapman would have called me, I would have told them I need a check for $200,000, and would have started shoring immediately, it would not have fallen.

They ignored advice, did not heed the warnings, and did everything they could not to get good advice, it is on the management company, the property manager and the Board, not on qualified construction professionals.

 

[SwinnyGG]

I have a rather large resume, you do not, so where do you think you stand on this side of the equation.

*eye roll*

No one cares about, or is impressed by, the alleged size or alleged voracity of your resume, dude.

What people DO care about, in this context, is clear presentation of facts with at least some minimum level of clear forethought backing them up.

Every single person in this thread is speculating; we all know that. Blanket statements about the facts, especially in concert with blanket statements about your alleged intellectual superiority, are the real waste of time here.

 

[SwinnyGG]

I know for as a 100% fact this was not a design issue

No you don't. The fact that you keep trumpeting that you know everything is not helping your case. You must be a real peach to work with in the real world.

If you think a property management company is qualified to understand these types of issue, you are the problem.

Huh? I never said anything of the kind. Some property managements companies may have the staff to understand a scenario like this, where a building in their charge is damaged and in need of extensive repair. But I never said (nor do I believe, nor do I believe anyone else in this thread has said or believes) that this particular property management group had the right expertise or made any good decisions.

The last time I checked, a mechanical engineer sits in a cubicle and speaks to no one, except when I call them and tell them that I need to change the size of a duct, so I really can not imagine a more unqualified professional other than a "computer engineer" to assert authority in this matter.

Ha! Once again... no one in this thread is truly aware of the 'resume' of anyone else in this thread. Funny how the only one spouting off about how strong their resume is, while denigrating the experience of others they know only by a handle in a forum in the backwaters of the internet, is YOU.

All you're doing is making yourself look like a clueless dick.

If you have nothing constructive to add to the discussion, go somewhere else. If you want to explain why you're so confident in the blanket statements you keep making, have at it. But at the moment you're 100% wasting everyone's time.

 

[Keith_1]

There are alot of design issues that exists, especially with lap lengths and coverage with balconies, but they don't result in the collapse of abuilding. There is a huge difference between some bad temperature steel, or a few bad bars on a balcony going bad, and the total failure of the entire foundational system. Yes, slabs do spall, but for a total failure is alot more than a #7 bar, it is cascading failure due to sure neglect and stupidity.

There is so much redundancy that the failure of a beam or column is not going to result in the total failure of a completed building, especially at 40 years. This thing was so neglected I would charge the property management company, the engineer and everyone else that did not file a report that it was a life saftey issue with at least aggravated manslaughter. This was 100% preventable, and even a basic understanding of structures would have prevented the loss of life that occured with Chapman.

Just accept that if the membrane was protected this would never have happened, and that even days before the failure, that if someone would have shored up the beams and de-compressed the columns that it never would have not of failed until it was repaired. Shoring can do alot more than you think, especially when it is a deflected load that so many think is the major cause of failure.

 

[Demented]

Chapman or Champlain? You may be thinking of a compmetely different building, which would explain a lot.

I hope your grip is good Keith 'cause I'm passing the crazy torch off to you.

 

[AutisticBez]

I have a question. If you know the construction to the south is damaging your property, why didn't you do anything about it?

 

[FJBnomics]

Keith, please refer to the section detail of the perimeter wall posted by structuralex in part 02 on 30 Jun 21 14:22 it clearly shows the structural support.

Here is the section detail dug up by IanCA. This sure looks like a turned down slab at grade supporting the South Retaining Wall, via direct load transfer to the hydrostatic soil below and thus the retaining wall supports the patio deck.

 

[Nukeman948]

This sure looks like a turned down slab at grade supporting the South Retaining Wall, via direct load transfer to the hydrostatic soil below??

That is correct. Also the drawings show piles on 12 foot centers supporting that slab around the entire perimeter to handle the load. Page 307 of 336 from the big set of drawings or page S1.

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[Keith_1]

thermopile,

There is no such thing as a "down turned slab" if it where it would be a footer or a grade beam. Slabs are on the ground, decks are suspended.

There is an 8" wall running from the West corner of the building to the East corner with #5 bars horizontal and vertical @ 12", and a section of wall from the East corner that is a 12" wall for 10' with #5 bars hortizontal and vertical at 16' centers. The corner is just what a corner is, because you always reinforce them to account for wind loading. Even in a single story CBS house you will have more steel and fill cells in the corners.

 

[Keith_1]

NuleDuke, so you have pile 12' on center, that shows nothing in relation to the perimeter wall. I actually know the order of construction, so I know that the sheet piles were installed before the piles, and I also know that there is not a pile under that wall.

 

[Nukeman948]

Kweef_1, You are looking at the drawings wrong. What you are calling a 12" wall for 10' is the section view of the slab. It is thickened, or turned down as some people say, around the perimeter of the building. The wall is 8" thick and its height varies. At the top of that drawing is the 9.5" pool deck. Those piles are under the thickened portion or footer of the slab. Please take a few minutes to look at the drawings that we are showing you. You can download the full set of drawings from the city of Surfside.

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[Keith_1]

thermopile, the one thing that you missed was that 12" section is called out at an elevation of 2' 2" which above whatever the slab elevation is. It really does not matter what the purpose of that 12" section because it does not transfer to the foundation. 2 is not 0,learn how to read a plan. I would be nicer if you people actually accepted reality.

 

[Nukeman948]

the one thing that you missed was that 12" section is called out at an elevation of 2' 2" which above whatever the slab elevation is.

Dude, the slab elevation is at 2' 2" above sea level. That is the reference point that they used here. Look at page S14 of the drawings. It is page 35 of 336. It shows elevation of each floor. It would be nice if YOU accepted reality.

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[zebraso]

2' 2" above sea level

That might be a kweef too far.

 

[SwinnyGG]

Long winded personal attack

You're, as is becoming typically for you in this thread, woefully incorrect. Not that it matters very much. I don't claim to know you, and at this point I don't care to. So how about we just stick to the facts. Maybe that will get you to understand why you're not correct.

what supports that wall? I'm talking foundation what carries the load? It there was a grade beam over piles piers or even a footers then that would be one thing, but there is nothing under that wall.

NuleDuke, so you have pile 12' on center, that shows nothing in relation to the perimeter wall. I actually know the order of construction, so I know that the sheet piles were installed before the piles, and I also know that there is not a pile under that wall.

When you look at the entire sheet, the pile layout is crystal clear. It's simple, really. Piles are spaced 5'0" or 6'0" from the slab edge. The slab had a thickened edge per the detail shown earlier in the thread, 8' wide. There are no columns above this ring of perimeter piles; the thickened edge of the slab is carrying load which has been transferred down from the grade level slab, through the retaining wall which bears on the thickened slab edge.

Say it over and over again all you want, but that perimeter wall carried a non-zero load. Period. End of story. To continue to say what you're saying is ignoring facts. If you want to modify your position and say that the perimeter thickened edge/pile placement/retaining wall/grade level slab detail is a bad design, say that all you want and I don't think anyone is going to really disagree with you.

Put your ego away and LOOK at the detail thermopile posted above. That vertical block drawn at 5' OC from the edge of the slab, with a twin another 12" further in? Those are the piles dude. Note that there's not a column above in the section; note the hook bar tying the grade-level slab to the retaining wall.

None of this is that hard to figure out if you stop rambling about how smart you are and actually read the drawings.

Nuke, you don't know where the ground is, there is an entire floor below that 2'2" elevation, you talk about being an idiot, you define it. Bottom of E-4 is 125' 8" to the top, learn how to add, it is a easy as 1+1=2

Again, seems like you're talking specifics without looking at drawings, or if you are actually looking at drawings, you can't read them. It's very clear what the basement TOS elevation is, and that there most certainly is not a secret hidden floor underneath it.

Just stop, man. You're embarrassing yourself.