×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# Miami Beach, Champlain Towers South apartment building collapse, Part 1260

## Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

10
Chapter 12
The Long Winter Awaits

As the leaves of late summer wither ever so slightly, their mottled discolorations foretell their future. Soon, with the waning of daylight, their photosynthetic journey will halt, and gravity will return their mineral elements to the soil below.

Huddled amongst these trees have assembled the technological elite, intellectually curious, and professionally trained people of this land. Their ranks infiltrated as they are with charlatans, quacks, and poseurs; all stare in awe at the mighty forest that surrounds them.

The sun dappling their faces as each one takes in the light. “I know the reason the light shines!” says one. “I, too, know” says another, “but the light, it shines differently for me; reflected as if cast upon a scattering of invisible orbs.”

A third mills about, claiming there is not light at all. “Behold the mighty PowerPoint and gaze upon its infinite wisdom! It showeth thus the absence of light entirely! This pixel here! And that smudge outlined in chartreuse!”

What a tremendous cacophony all these voices make. It reverberates through the trunks like a flock of magpies what have been into the fermented crabapples.

But the light is growing ever dimmer. The playing of the shadows waning as the stomata gasp their final breaths. Darkness. Coldness.

The bleak monotony of winter marches ever closer. These ravenous minds yearn for a brightening sky to inform their views but none awaits. Only a monochrome landscape, stretching from woodland floor to the low gray stratus that hug the ground.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Spartan5)

Liked, for stomata among other things. And yes, the light does shine differently, for those of us in the other hemisphere: Spring approaches, not winter.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

USA Today has had someone review the medical records. Apparently few autopsies were performed for religious reasons. At least 9 victims of 98 dead may have initially survived Surfside condo collapse, but were not found by rescue teams, investigation shows

In addition to the woman’s voice in the basement, which may refer to the teenage girl from 204, there are suppositions about victims from 704 and 1002, and descriptions of injuries to victims from these units:
• 212
• 501
• 802
• 811
• 1010
• 1111

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MaudSTL)

Apparently few autopsies were performed for religious reasons.

From the article:

#### Quote:

Only one autopsy was performed. Otherwise, technicians conducted only external examinations and, in some cases, X-rays

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MaudSTL (Computer)25 Aug 21 13:06 The NYT reviews the events around the penthouse addition and mentions the crane collapse. ‘They Were Bullies’: Inside the Turbulent Origins of the Collapsed Florida Condo)

What a damning article on the whole process of design construction and permitting in this region of the country. The only thing I would say, from my experience, is that I don’t think things have changed all that much. It’s not unusual to see Cities, counties, and the State get intimidated into accepting substandard projects by developers and their lawyers.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Re: the NYT article linked above.

It says that Surfside had only a part-time building inspector and "delegated inspections of the towers back to the Champlain Towers builders...".

I may be overly naive here, but it seems to me that Surfside should have hired an additional Special Building Inspector, then. And assign that person to this job. The whole point of allowing this building was to bring in money to Surfside (according to the article). So it would seem appropriate to "spend a little to get a lot".

Besides, wouldn't the permit fees cover the cost of the inspection? That IS the point of permit fees, is it not?

spsalso

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

MaudSTL

"USA Today has had someone review the medical records. Apparently few autopsies were performed for religious reasons. At least 9 victims of 98 dead may have initially survived Surfside condo collapse, but were not found by rescue teams, investigation shows"

Thanks for the article. I find it highly disturbing on so any levels.

"Fire rescue logs indicate that officials knew hours after the 1:25 a.m. collapse at Champlain Towers South on June 24 that survivors remained in the mountain of debris. Rescue teams were in contact with live victims, and search dogs – one of the department’s most reliable indicators of life – confirmed human life."

You'd think as a "crime scene" autopsies would be mandated.. but suddenly "it was never a crime scene" but a death investigation??

Seems the County decided to pick and choose which records to keep or dispose of as well.
So much incompetence and subterfuge at the same time!

And once again the couple in 811..that were found holding their IDs...no visible injuries that would lead to death.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Just in case anyone missed it, this is one of the most detailed and touching records of the search and rescue efforts. And is it from any one of our tax paid employees? NO. It's from an Israeli Commander ...

Miami: A search and rescue diary:

https://www.israelhayom.com/2021/08/06/miami-a-sea...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MaudSTL (Computer))

In addition to the woman’s voice in the basement, which may refer to the teenage girl from 204, there are suppositions about victims from 704 and 1002, and descriptions of injuries to victims from these units:

212
501
802
811
1010
1111

From the article:
Another person who did not appear to have immediate life-threatening injuries was Gloria Machado, 71, who lived in Unit 1111.

Records show Machado suffered “fractures of the skull and facial bones, ribs, spinal column, legs, and feet,” as well as “global laceration of the scalp with multiple skull fractures and multiple facial fractures.”

Six minutes after the collapse, however, 911 operators received a call from a man claiming to be Machado’s son, fire rescue logs show.

The caller said he “received a call from his mother” and she was “trapped inside her apartment 1111 and unable to get out,” logs show.

Quite honestly, those injuries might not have immediately killed her, but they seem inconsistent with someone being awake/alert enough to make a call. Also, she said she was trapped in her apartment, not that not that it had collapsed.

There was some speculation a few threads back that before the actual collapse, the structure may have sagged and twisted such that doors could not be opened. I wonder if the call was made before the building fell?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley (Structural)25 Aug 21 17:47 Quote (IEGeezer (Industrial)

Charley - can this be moved to current page? Should I copy and paste there?
Obviously I did not see your call to move to a new location.
Thanks,]

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)25 Aug 21 18:44)

Quote (Vance Wiley (Structural)25 Aug 21 17:47
Quote (IEGeezer (Industrial)
Charley - can this be moved to current page? Should I copy and paste there?
I don't know how to move it, I don't even know how to close my "part 11". but if it were my post,
I would edit it - copy the text form the edit page (where you can change it) - and paste into a post on this page.

Sorry for mansplaining it...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

3

#### Quote (Quote (IEGeezer (Industrial)) (When you are mixing on site, you may run out of time doing a large slab. In that case, did they pour the bottom half first and then come back the next day to finish the pour? Could that have led to "delamination?"))

It has been mentioned earlier that some contractors placed slab pours to the level of the bottom of the upper reinforcing and stopped there to lay the upper reinforcing on the concrete and avoid the use of high chairs. This would require a delay for the slab to set for foot traffic and to support the reinforcing.
The proper casting of a concrete member - beam, column, slab, footing, or wall is monolithic - one casting with reconsolidation between the layers of placement - or through a properly prepared cold joint.
Had I caught a contractor leaving an as placed joint surface in concrete he would have been sandblasting the entire surface to remove the interface surface sufficient to expose aggregates solidly embedded in the prior pour. That is a bit expensive.
On one project the contractor did not place the temperature reinforcing in a topping slab which was placed over precast tees. The flanges of the tees had been intentionally roughened just like DOT girders and were correctly prepared for a topping slab placement. The contractor should have called for an inspection. The remaining pile of reinforcing was the clue. He was directed to place the reinforcing, clean the slab, and coat the surface with epoxy. The reinforcing was temperature reinforcing - not the principal reinforcing providing strength for floor support, as the reinforcing of slabs at CTS was.
Cold joints were a problem at FIU. What is with the Florida contractors?
The concrete is/was likely mixed in a batching plant and trucked to the site. It might have been pumped or perhaps hoisted in buckets to the elevation being placed if there were a crane on the site. The handling of concrete, even in the 1980s, was clearly defined in the codes and industry practice. Batch times, number of turns of the drum on the truck, slump, added water - all are supposed to be controlled. Mixes are and were designed and load tags provided with reference to specific approved mixes, and the concrete sampled for slump and compressive strength. And it remains a problem today.
Reinforced concrete is the most structurally important product in most structures that is actually created on the job. Under less than factory controlled conditions - like rain, temperature, and other factors. But on the job it becomes just hard work, with a deadline only an hour away if you want to finish it correctly.
And yes - that is basically delamination by default.
Thanks,

Thanks, Charlie

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

> There was some speculation a few threads back that before the actual collapse, the structure may have sagged and twisted such that doors could not be opened. I wonder if the call was made before the building fell?

Yes that seems likely, in the x11 stack at least. That is probably why 811 couldn't escape, even though they were awake and aware enough to get their IDs and choose their death pose (that was the speculation in the previous thread). The timestamp on the call that the woman in 1111 made to her son would be extremely interesting.

It all lines up, to me, with something failing low down in one of the x11 column stacks (L or M 9.1 probably), leading to load distribution (with noises and deformation) for some minutes until the connection with that M9.1-11.1 beam breaks, the pool deck becomes unsupported and starts puncture-shearing the deck columns.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (local 10)

The National Institute of Standards and Technology held a news conference Wednesday morning to discuss its investigation into the June 24 partial collapse of the Champlain Towers South condominium building.
NIST establishes team of experts to investigate cause of Surfside building collapse

#### Quote (NIST)

NIST Establishes Expert Team to Investigate the Champlain Towers South Collapse

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Red Corona (Computer)25 Aug 21 20:18)

It all lines up, to me, with something failing low down in one of the x11 column stacks (L or M 9.1 probably)
(from a number of sources:)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

>It all lines up, to me, with something failing low down in one of the x11 column stacks (L or M 9.1 probably), leading to load distribution (with noises and deformation) for some minutes until the connection with that M9.1-11.1 beam breaks, the pool deck becomes unsupported and starts puncture-shearing the deck columns.

And yet, 611 (and the ground floor tenants) were the only ones that got out. Might the upper floors have actually deformed before/more so than the lower floors? Would the twisting (for want of a better word) have gotten worse as you went higher, despite the initial failure being at the base?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Gosh Golly Since the units were defined on the prints, IF they had just poured sheer walls between the units, the building would probably be standing today.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley)

some contractors placed slab pours to the level of the bottom of the upper reinforcing and stopped

I just want to second what Vance is saying. I find it quite unbelievable that this practice may be occurring in Florida. In my opinion, ANY STRUCTURAL SLAB THAT HAS A HORIZONTAL CONSTRUCTION JOINT WITHIN ITS DEPTH IS SUSPECT. I'm not saying this is never done. But if required special care is demanded, and would usually be specifically detailed on the drawings to ensure it's properly done. It should never just be left to the contractor to install these at their whim.

Separately, the broken MC core samples, w/ loose rebar, are likely NOT the result of horizontal CJ's. They are much more likely the result of corroded rebar causing spalling within the concrete.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
From the surveillance video (which starts after the start of the fall), I seem to see the entire south (poolside) face of the center (units x10 & x11 including the top PH) of the east wing fall intact. What appears to be the skyline of the corridor to the top PH seems to appear (stationary) as the face falls. This requires the floors and roof to tip toward the pool. Since the face of x10 & x11 units remain connected, I don't see the doors getting twisted. We do see twisting in the ring camera video though?

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Those cores went through previous repair work.

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

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

SFCharlie,

Ring video is picking up micro-level twisting and wracking going on in the structure pre-collapse. This would not be visible in the macro-level surveillance video. At least that's my take.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

From the surveillance video (which starts after the start of the fall), I seem to see the entire south (poolside) face of the center (units x10 & x11 including the top PH) of the east wing fall intact. What appears to be the skyline of the corridor to the top PH seems to appear (stationary) as the face falls. This requires the floors and roof to tip toward the pool. Since the face of x10 & x11 units remain connected, I don't see the doors getting twisted. We do see twisting in the ring camera video though?
The twisting could have remained internal to the building, or that specific stack. The X11 stack had the most internal alteration of walls, with 10 out of 12 kitchens having the CMU walls removed, and 6 out of 12 having the CMU walls in the laundry removed.

These were on the drawing as not structurally integral, but in a packet of errors, what's to say these walls were not giving some support to the slabs.

The doors would be located between both sets of these walls.

Edit: Another thing to note is, this building had pretty much 100% coverage with hurricane rated glass.
Having just got off a job where we were literally hammering stainless steel on top of glass (and welding it too, oh the joys of 90* max inter-pass temp. FML), a little twist in a building that'll stop a door from opening wont even make that glass wince. The crappy aluminum or stainless frames around the glass have enough crush space that they'd give way about 2-3" before the glass even touches something hard. That glass wouldn't have broken until it was crushed. Layers upon layers of latex paint too. Even at higher quality, that side of the building probably wouldn't have shown us much.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
TheGreenLama, Demented Thanks for responding!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Debirlfan)

…611 (and the ground floor tenants) were the only ones that got out. Might the upper floors have actually deformed before/more so than the lower floors? Would the twisting (for want of a better word) have gotten worse as you went higher, despite the initial failure being at the base?

Everything is speculation, of course.

But if you go to 34:36 in the 911 calls, there’s a call starting at 1:29:57, seven minutes after the collapse. They’ve edited out the unit number, but it’s likely to be the son of Gloria Machado in 1111. He says his mother told him “there was an explosion in her building” and “She’s trapped in her apartment.”

Given the timing of the call and the verbiage, I think you can make the argument that Ms. Machado survived the collapse, made the call, and then expired before rescue. Ms. Machado thought there had been an explosion in the building. She would have had no idea that the building itself had collapsed. All she could have known is that she was trapped in the rubble of her ruined apartment. What I’m trying to say is that the wracking of her door frame was unlikely to have been the reason she couldn’t get out, especially considering the extent of her injuries.

As for 811, we will never know why they grabbed their IDs and died in each other’s arms. Rather than being stuck in their apartment as a result of wracking, though, perhaps like the Nirs in 111 they believed they were experiencing an earthquake. When you’re in a high rise in an earthquake, you’re supposed to stay away from glass and wait it out, and then, after the shaking stops, put on your shoes, grab your purse, and evacuate. Maybe that’s what the people in 811 were preparing to do, having no way to anticipate a building collapse.

We know from what the Gonzalezes, who miraculously survived after plunging down from 904, said that the building was shaking violently on their level, so it would be natural to think it was an earthquake. The Gonzalezes’ decision to try to escape saved them…they got lucky. Like Ileana Monteagudo had done several minutes earlier in 611, the Gonzalezes in 904 got their apartment door open and ran out into the hallway.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

>But if you go to 34:36 in the 911 calls, there’s a call starting at 1:29:57, seven minutes after the collapse. They’ve edited out the unit number, but it’s likely to be the son of Gloria Machado in 1111. He says his mother told him “there was an explosion in her building” and “She’s trapped in her apartment.”

There was a guy on the officer's body cam saying that his mother was stuck in her apartment. The impression I had was that she was in the still standing part of the building? He might have been the one who called 911?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Given the extent of the injuries described I’m amazed that she’d be able to locate and operate her phone in the pitch dark in any amount of time, let alone within minutes of the collapse.

I would have also expected that she would have been described to dispatch as seriously injured and in need of immediate medical attention instead of trapped. And probably would have called 911 first herself.

Which makes me think the call was placed before the whole thing came down but after some shaking and wracking of the building took place.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I noted poor, powdery concrete in earlier snaps of the rubble pile but I am not a concrete guy. Is it the expert view that this stuff looks wrong? We also don't see that much corrosion of the rebar on general view (foot of that columns in the article being an obvious exception). Is corrosion/expansion/concrete cancer in the overall structure really in evidence here?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Debirlfan)

There was a guy on the officer's body cam saying that his mother was stuck in her apartment. The impression I had was that she was in the still standing part of the building? He might have been the one who called 911?

The guy in the street trying to get the cops to save his mom seemed to be indicating the part still standing. I can’t decipher whether he says the apartment number. Go to 6:37 in this bodycam video and see if you can hear a unit number. He is talking to the cops at 1:36:35, which is 7 minutes after the 911 call about the mom trapped in her apartment and 14 minutes after the building collapsed.

#### Quote (Spartan5)

Which makes me think the call was placed before the whole thing came down but after some shaking and wracking of the building took place.

Blue Shirt Fire Admin from 1209 described hearing something falling in the apartment and then described the sound of the building collapse as a jet. It’s questionable whether 1209 even heard the deck collapse. Ileana Monteagudo in 611 described the deck collapse as a supernatural force that woke her up. Because of these statements, I am having a hard time imagining someone in 1111 describing the deck collapse as an explosion. But assuming one person’s supernatural force is another person’s explosion, let’s imagine that Gloria Machado called her son immediately after the 1:15 deck collapse. It doesn’t make sense to me that her son would then wait until 1:29:57, nearly 15 minutes after the deck collapse and 7 minutes after the building collapse, to call 911 to report that his mother’s building had had an explosion and she was trapped in her apartment.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Curiously, the base of the column that was shown as an example of "astronomical" corrosion didn't fail.

It's still standing.

spsalso

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MaudSTL)

let’s imagine that Gloria Machado called her son immediately after the 1:15 deck collapse. It doesn’t make sense to me that her son would then wait until 1:29:57, nearly 15 minutes after the deck collapse and 7 minutes after the building collapse, to call 911 to report that his mother’s building had had an explosion and she was trapped in her apartment.

Let’s imagine, that she, like my mom who is of the same vintage, takes a few moments to get her bearings at 1:15 in the morning. And instead she called moments before the building collapsed after waking up, wandering about a bit, finding she can’t open the door, Gondi go her phone, and calling. That’s the better part of 5 minutes right there.

Where was here son calling from? If it was anywhere other than the immediate area he would have had to work a bit to get patched into the Miami-Dade County dispatch, no?

#### Quote:

Monteagudo, who is in her 50s, woke up from a restless sleep and heard strange noises. She initially believed they came from the open sliding door to the oceanfront balcony.

“I ran and tried to close it but I couldn’t, I imagine because it was unlevel already because of all the movement,” she recounted. “I heard a crack and when I looked, I saw a crack traveling in the wall two fingers thick. Something told me, you need to run.”

What did the building experience between the time Monteagudo was woken up by “strange noises” and the time after cracks started running in the wall, but while she ran about collecting credit cards, ID, various religious tokens, and then ran down several flights of stairs before the collapse happened. I can’t imagine that everything was serene.

Like you said, it’s all speculation. None of it will be resolved with any certainty. And even if it is, it sheds no relevant light on anything. We’ve had some 4,000 posts of that. Maybe it’s fodder for the lawyers. But other than that…

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Maud, its possible for someone to have died in the standing portion of the building. Very little has been said for the state of the standing portion. Not sure if anyone went door to door either. Perhaps those who could escape, did so via fire ladders or down the stairs. Is it possible someone died in the standing portion? Then later, they were found crushed in the wreckage after it was demolished?

There was internal damage in portions of the standing portion. Surely there must have been rooms where people may have been stuck by doors that wouldn't open?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Spartan,

"None of it will be resolved with any certainty. And even if it is, it sheds no relevant light on anything. We’ve had some 4,000 posts of that. Maybe it’s fodder for the lawyers. But other than that…"

Both NIST and Lawyers will re-interview all of these survivors/witnesses. It won't be "fodder" because they will ask better, more deliberate questions and have bilingual interviewers. Unlike journalists looking for a sensational soundbite.

Yes, we on here are at an extreme disadvantage trying to reinterpret any of the previous interviews.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

AutisticBez

Fire fighters did go completely thru the standing portion of the building that morning.

You can see at the very top, that is one of them with a flashlight.

Also, I was able to tie all of the deaths to the Units of the collapsed portion, I kept a spreadsheet. I started it because I knew the original number of 149 was incorrect. Cava knew the missing was under 100 within 2-3 days and never corrected herself... I wonder if this lie was upheld to help increase the state of emergency or fema funding?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Great post! Report Optical98)

You can see at the very top, that is one of them with a flashlight.

There is also a faint glow of flashlights on the stairwell landings.

What I am interested in is that vertical row of red lights. Are those exit signs with batteries at the end of the halls? (I'll start looking)

Found it...

That looks like what I'm seeing.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The core sample in this image shows disruption of rebar to concrete bond, but I just don't see the corrosion necessary, in this sample, to cause the expansion. Now with this small of core hole, it is possible drilling core broke it up, but it would seem proper concrete strength, mix and installation would have far better bond that what this image shows. It appears concrete itself is more suspect or perhaps how it was installed? If same crew as Demented's watery low aggregate looking mix, did this repair, then installation and materials seems more likely?

Edit: Ignore the marks and comments, as I just grabbed this from the lead in image to another long winded read and think out loud video for profit, which is just a bunch of hot air.......

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The core sample in this image shows disruption of rebar to concrete bond, but I just don't see the corrosion necessary, in this sample, to cause the expansion.

The concrete for that particular core sample does look particularly degraded (powdery). And at least from this view the steel looks relatively clean. It is still odd that the separation is occurring at the steel. Core samples don't normally break up. I'm not a materials expert, so I'll keep an open mind on causation until some actual testing is done.

Here is an image of that core from earlier in the thread Part 7, 18 Jul 21 1:10.
By the way, could anyone provide the link to the Morabito Phase IIA report where these come from. I can no longer find it. Is it within the Surfside document trove?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Here's the corroded column base from the NIST vid. I'm guessing it's one of the deck cols. Before anyone says a car hit it, it could have been hit with a bulldozer a few times during debris removal.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)(OP)26 Aug 21 16:56)

Now who's resorting to power-pointy do-dads

I don't have the literary skills of some of posters, so I had to join "Team" do-dads, to get my points across!

#### Quote (TheGreenLama (Structural)26 Aug 21 17:22)

link to the Morabito Phase IIA report where these come from. I can no longer find it. Is it within the Surfside document trove?

I looked in Surfside document trove and could not find it either. I thought that is where it was originally found, as it was buried in the 80 page Association Meeting Minutes.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AusG (Petroleum)26 Aug 21 03:03 I noted poor, powdery concrete in earlier snaps of the rubble pile)

Too much water in the mix makes concrete weak and powdery. Is there yet available any test reports of the strength of cured cylinders cast from the concrete used at this site and cured in the lab? Any test results of cores taken in the last year? Pre or post collapse.
There have been comments on rainwater possibly causing weakening or dissolving rock strata below the building.
Now the question - about aggregates in Miami. Are the aggregates sensitive to degradation by salt water exposure? In the FIU photos of broken concrete almost all the aggregates I saw were split by the fracture. Good bond, not so good aggregates? Can we see aggregates in the crumbles here?
A comment on "congestive rebaritis" - I do not see anything out of the ordinary by viewing the pics of the columns - and if rebar is tight there is a max aggregate size to be used. At column bar splices, it is common practice to offset the bars from below to do a contact lap just above the floor slab pour , in this case. There is a detail of such a condition and it appears correct to me - bars offset at 1:6 slope and the offset should be offset toward the center of the column (I do not recall seeing the direction to orient the offset as a requirement on the drawings, but it is the practice). Reinforcing needs to be separated enough to allow good bond and load transfer between the concrete and reinforcing, and the codes address this. Mix properties as placed and proper consolidation of the concrete is required. Measurements will confirm compliance or non-compliance.
I am not sure the rebar spacing was a major contributor to the collapse. One column on line "L" is 24X12 and has 12 - #12 bars for about 5.3% steel, with the maximum allowed being 8%. Column on Line G , 14X18 and 10 - #11 is 6.07%, less than the 8% maximum.
Thanks,

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (I am not sure the rebar spacing was a major contributor to the collapse. One column on line "L" is 24X12 and has 12 - #12 bars for about 5.3% steel, with the maximum allowed being 8%. Column on Line G , 14X18 and 10 - #11 is 6.07%, less than the 8% maximum. Thanks,)

Unless things have changed... at the splice you can have 4% (main steel)... 4%+4% spiced bars = 8%.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley)

I do not see anything out of the ordinary by viewing the pics of the columns

That pic above that SFCharlie posted looks odd to me. In it there are 4 bars all in line and basically touching each other at the corner. Bundling of bars in EQ zones is done all the time. Usually the shape is triangular w/ 3 bars per group. Here, with them all in line, it seems like concrete placement could be a problem.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Optical98)

Thanks Optical98!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Regarding columns with too little or too much rebar, here are examples of each.

Too much.

Too little

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (dik (Structural)26 Aug 21 18:50 Quote ( with the maximum allowed being 8%. Column on Line G , 14X18 and 10 - #11 is 6.07%, less than the 8% maximum. Thanks,) Unless things have changed... at the splice you can have 4%... 4%+4% spiced bars = 8%.)

The amount of steel within the lap zone is not used to determine the capacity of the column.
The longitudinal reinforcing up the column is the determining factor and the focus of the 8% limitation.
If there are moments at the top of the slab/bottom of the column, the development length for any bar in tension should be checked.

BIGTIME EDIT - - I do not see the logic in this but

#### Quote (dik (Structural)26 Aug 21 18:50)

is correct - the limit of 8% DOES apply to splice zones in the ACI318- 2014 Section 10, as follows (with comments). What this does today is require splice collars so all reinforcing stays in line and reduces the congestion if more than 4% is needed
From http://aghababaie.usc.ac.ir/files/1506505203365.pd...

10.6.1.1 For nonprestressed columns and for prestressed
columns with average fpe < 225 psi, area of longitudinal
reinforcement shall be at least 0.01Ag but shall not exceed
0.08Ag.

R10.6.1.1 Limits are provided for both the minimum and
maximum longitudinal reinforcement ratios.
Maximum reinforcement—The amount of longitudinal
reinforcement is limited to ensure that concrete can be
effectively consolidated around the bars and to ensure that
columns designed according to the Code are similar to the
test specimens by which the Code was calibrated. The 0.08
limit applies at all sections, including splice regions, and
can also be considered a practical maximum for longitudinal reinforcement in terms of economy and requirements
for placing. Longitudinal reinforcement in columns should
usually not exceed 4 percent if the column bars are required
to be lap spliced, as the lap splice zone will have twice as
much reinforcement if all lap splices occur at the same
location.

I learned something toeday. Thank you,

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Report: Evidence of extensive corrosion in collapsed condo

#### Quote (AP)

“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.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (TheGreenLama)

he concrete for that particular core sample does look particularly degraded (powdery). And at least from this view the steel looks relatively clean. It is still odd that the separation is occurring at the steel. Core samples don't normally break up. I'm not a materials expert, so I'll keep an open mind on causation until some actual testing is done.

Here is an image of that core from earlier in the thread Part 7, 18 Jul 21 1:10.
By the way, could anyone provide the link to the Morabito Phase IIA report where these come from. I can no longer find it. Is it within the Surfside document trove?
Concrete was removed at partial depth to where rebar could be inspected. Where no full depth repairs were required, steel was sand blasted and coated. A random combination of repair mortar, bagged concrete mixed on site, and pumped concrete with the slump of a snow man in Florida, was used to fill back the excavated areas. In some areas, new steel was just laid besides, on top, or below existing.

Partial depth repairs were done from above and below in the same locations, mostly around the planter locations. They went 3-6" down, and 3-6" up in their excavation to expose the rebar.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The following is an excerpt from:

An ACI Standard
Building Code Requirements for Structural Concrete
(ACI 318M-14) and Commentary (ACI 318RM-14)
Reported by ACI Committee 318
Chapter 10 Columns, page 156

I don't know if this is latest or correct source, so I attached document to this post.

R10.6—Reinforcement limits
R10.6.1 Minimum and maximum longitudinal reinforcement
R10.6.1.1 Limits are provided for both the minimum and maximum longitudinal reinforcement ratios.

Maximum reinforcement—The amount of longitudinal reinforcement is limited to ensure that concrete can be effectively consolidated around the bars and to ensure that columns designed according to the Code are similar to the test specimens by which the Code was calibrated. The 0.08 limit applies at all sections, including splice regions, and can also be considered a practical maximum for longitu- dinal reinforcement in terms of economy and requirements for placing. Longitudinal reinforcement in columns should usually not exceed 4 percent if the column bars are required to be lap spliced, as the lap splice zone will have twice as much reinforcement if all lap splices occur at the same location.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

This 'too much rebar' thing. It's pretty conclusive that it's against code (thanks to people above who've looked up the rules). But those columns only had too much rebar in the splice region, right? Which was immediately above each floor. Is there any indication that a column initially failed in that area (immediately above the ground floor, presumably, as the load on the columns is highest at the bottom of the building)?

Does it apply at the base of the columns in the garage as well? I wouldn't have thought there would be any splicing there, as there isn't a column beneath that slab, and it didn't look like it in the pictures where they'd cleared the rubble but the columns were still present. And we know that, apart from maybe M12.1, all those columns were still standing at basement level.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (All About Money (Aerospace))

I stand corrected. Thanks for correcting - I had just edited my original reply to @dik, with the comments pasted there.
The 4% limit was hiding in the back of my mind, and I was surprised when I saw the 8% - really! But there it was in bold - but without the comments.
The takeaway is a good thing - increase the size of the column if you need to exceed 4% reinforcing OR use splice couplers.
Now to find a copy of ACI318 that was in effect in 1980.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (I learned something toeday. Thank you,)

Not a problem... one of the features of this website. I haven't done a real concrete tower for two decades, but at that time the general maximum practical reinforcing ratio was about 2.5% to 3% (and max reinf at splices was about 6%) with column sizes and concrete strength only changing as needed to accommodate greater loads.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Red Corona (Computer)26 Aug 21 23:33 This 'too much rebar' thing)

I have corrected my original post about % and added one just minutes ago.
The condition of lapped reinforcing generally applies to the top of foundations also because it is difficult to set and hold a large tall cage of reinforcing over a deep pile cap or footing and while placing concrete. The dowels can be tied to mat reinforcing and most of the time no bracing is required.. But there are a lot of times the dowel bars are not straight vertical and in the right place.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

in other news:

Millennium Tower sank another inch this past month.
Underpinning to bedrock.
shoulda in the first place.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (raymiepo (Computer)27 Aug 21 01:09)

Let's see how good Demented's Math skills are. Question is how many Harbor Freight Winches will it take to right the leaning Millennium Tower on the other Coast? We were leaning 17" before the 100M repair started in May, but now we are leaning 22"?

Perhaps SFCharlie can come up with a 'do-dad' fix? EDIT: Perhaps a series of Flying Buttresses like the old Cathedral's?

Next Question: Who wants to live in a High Rise on either Coast?

Link to NBC Bay Area article:

https://www.nbcbayarea.com/investigations/millenni...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Millennium Tower fix = 2 do-dads and a tar kettle in the basement~

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (raymiepo (Computer)27 Aug 21 01:09)

Millennium Tower sank another inch this past month.
I guess it is not an Engineering Failure nor Disaster yet, but I'm surprised I can't find a thread for the "Millennium Tower"

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (All About Money (Aerospace)27 Aug 21 01:51)

how many Harbor Freight Winches will it take to right the leaning Millennium Tower on the other Coast?
When the new span of the bay bridge was built, they brought in the "Left Coast Lift" (real name, I believe), the largest floating crane west of the Mississippi...

#### Quote (Perhaps SFCharlie can come up with a 'do-dad' fix?)

(that will take a while, but I'll get on it)

#### Quote (Next Question: Who wants to live in a High Rise on either Coast?)

SFCharlie for one

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

I cant't find tread for Millennium Tower

Its under SF Tower Settlement Part II - Key word here is "yet" but engineers are working on making it worse as we speak. Unbelievable!!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley)

Now the question - about aggregates in Miami.
There is aggregate...

but as you observe it looks barely harder than the cement, and is pale coloured presumably limestone.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

https://www.nbcbayarea.com/investigations/new-tilt...

as far as aggregates go... if there are chlorides in it, it can reduce the passivity of the concrete (not cement, that's the pozzolan used to make concrete) and reduce the ability to resist corrosion.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Sorry for the diversion but a promise is a promise

There, that wasn't so hard...
Now back to the aggregate

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

SF Millenium Tower just needs they do what they are already doing, but harder and on the other side to even it up.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

What you're seeing with Millennium Towers is the first phase:

Pound a whole buncha pilings in, all the way to bedrock.

IF the building tilts too much during the first phase, bungee cords are used as safety devices, and are tied around that cucumber shaped building nearby.

Phase two involves a whole lot of hydraulic jacks. One is placed above each pile, and the jacks lift the building back up to vertical. There will be a guy (paid double time, by the way) up on top with a 24" level. He will be in constant communication with management.

Phase two point one is removal of the bungee cords. Great care will be taken to avoid them "snapping" out a window or three on adjacent buildings.

Phase three is filling the whole cavity where the hydraulic jacks are with, yes, CONCRETE.

Phase four is the after-party, which will take place in the East Bay. Just in case.

spsalso

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Do-Da Do-Da and now...
Back to the aggregate in Miami (I know the group trying to build the new Panama Canal locks ran into a problem. They were going to use the rock quarried out of the lock site, but there was an unrecognized fault running through it and the rock was too fractured to meet spec, so they had to find a new quarry...)

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
From the Miami Herald > AP > Miami Herald article...

#### Quote (Abieyuwa Aghayere, a Drexel University engineering researcher who reviewed the NIST video)

“The white color just stuns me,” Aghayere said. Instead of seeing aggregate material mixed into the concrete, “it’s just homogenous,” he said, a likely indication of saltwater damage.

#### Quote (dik (Structural)27 Aug 21 02:29)

as far as aggregates go... if there are chlorides in it, it can reduce the passivity of the concrete

Saltwater corrosion of the aggregate or just "we don't need no stinkin' aggregate"

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Back to Millennium Tower for just a bit. If you want to reduce settlement do not drill 36" dia. piles through the unconsolidated marine clays and give a path to release the excess pore water pressure from the 10' thick matt sitting on them and thereby increase the settlement instead of slowing it down. I'm no geologist but my god you don't have to be to know this was a very bad idea.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

CTS is not the first one in Florida - -
While searching for a copy of ACI 318-77 I found this:

Source: https://www.concrete.org/publications/internationa...
Title: Cause of the Condominium Collapse in Cocoa Beach, Florida

Author(s): H. S. Lew, N. J. Carino and S. G. Fattal

Publication: Concrete International

Volume: 4

Issue: 8

Appears on pages(s): 64-73

Keywords: buildings; concrete construction; failure; flat concrete plates; punching shear; shear strength; strength; structural analysis.

Date: 8/1/1982

Abstract:
Gives the results of an investigation into the collapse of a five-story, flat-plate condominium building in Cocoa Beach, Fla. The collapse occurred on March 27, 1981, while the casting of the roof slab was in progress. Eleven workers were killed and 23 were injured. The investigators conducted on-site inspections, made laboratory tests, and made analytical studies. It was concluded that the most probable cause of the collapse was inadequate punching shear capacity in the fifth-floor slab to resist imposed construction loads. The analysis indicated that punching shear stresses at many slab/column connections were close to the ultimate capacity specified by the Code (ACI 318-77). Consequently, it was Concluded that a punching shear failure at a heavily stressed location triggered a succession of failures at other locations, resulting in the downward collapse of the entire structure.
Dejavu all over again?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

My money is on bad aggregate in worse concrete, with too little of it around threadbare steel, in not enough beams and shear walls. Add weather and poor maintenance and this thing is a mudpie with nice curtains and a pool. And that is just from listening to y'all put it all together.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@VanceWiley - I believe somewhere in the previous threads someone posted a link to the federal investigation report on the Cocoa Beach collapse. I also found this article from the day after CTS came down:

Structural engineer sees similarity in deadly South Florida, 1981 Cocoa Beach collapses

"...the 1981 Cocoa Beach collapse inspired a law that required structural engineers and inspectors...to undergo a qualification program to 'enhance the quality control and inspection during construction of 'threshold buildings.' ' Such structures include those over three stories or 50 feet or built for more than 500 people."

Unfortunately, both of these buildings were under construction at the same time, so the additional regulations came too late for CTS. It would also appear that those lessons may well have been lost on subsequent inspectors over the years, if Surfside's questionable repair approvals are any indication.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Thermopile)

Let's see how good Demented's Math skills are. Question is how many Harbor Freight Winches will it take to right the leaning Millennium Tower on the other Coast? We were leaning 17" before the 100M repair started in May, but now we are leaning 22"?
You know damn well they'll burn out straight out of the box and burn the place down. I don't think China was able to produce aluminum when my ref books were printed. Anyone have strength data for pot aluminum?

I like spsalso's plan. He's just missing some whistles and hand gestures.

Edit:
The local aggrigate mines in the area are Limestone mines, especially if it came from Cemex.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (RandomTaskkk (Structural)27 Aug 21 06:47 )

Be careful what you ask for? Are you sure you want all the "do-da's" and powerpoint guru's to invade a forum that has been lean, mean and focused?

#### Quote (Demented (Industrial)27 Aug 21 09:09 )

Quote (Thermopile)

Now that I have been exposed, I guess I will have to reinvent myself again. Perhaps this time Demented2 ? or perhaps SFDoDa ?

I too like spsalso's plan....They were working on wrong side………

Edit: Back to CTS Aggregate.......

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Demented)

Those cores went through previous repair work.

I went through the Oct 14 board minutes that Optical98 provided [https://s3.documentcloud.org/documents/20985354/20...], where the images of the cores samples are shown, and I found no mention of the cores being made particularly to inspect previous repairs. Is this core location requirement coming from somewhere else, and if so do you remember where that may be found?

A couple of highlights from the board minutes (for those who haven't already read them):

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (RandomTaskkk (Structural)27 Aug 21 06:47)

I second the motion!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (All About Money (Aerospace)27 Aug 21 12:34)

Are you sure you want all the "do-da's" and powerpoint guru's to invade a forum that has been lean, mean and focused?
I promise to leave them in peace and quiet.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I caught on day 1. Pretty sure others have known for a while. :P

@TheGreenLama
They weren't to inspect previous repairs. Some of the cores just happened to fall in the location of old repair work, especially those taken from the pool deck and lobby driveway. The concrete started to fail within a few years of building completion due to corrosion with rebar and spalling and failed or no waterproofing. 2 main restoration projects were undertaken, both of which were jobs that failed or were never completed. The Morabito work would be the 3rd main project going at some of these areas.

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

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (AusG (Petroleum)27 Aug 21 02:19)

Quote (Vance Wiley)
Now the question - about aggregates in Miami.
There is aggregate...

The google search was "Florida limestone aggregate concrete structural strength"

Effects of Coarse Aggregate on the Physical Properties of Florida Concrete Mixes

#### Quote (The coarse aggregate produced in Florida and used in structural concrete require special consideration with regard to relative strength,)

Also, please see the attachment: (everything you could want to know... ...I got as far as the "Mohr circles" and got lost...that was on the first diagram.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@Demented
Thanks. That's what I figured you meant, but just wanted to make sure.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
The attached paper goes with the slides attached above...

#### Quote (SFCharlie (Computer)(OP)27 Aug 21 19:12)

Also, please see the attachment: (everything you could want to know... ...I got as far as the "Mohr circles" and got lost...that was on the first diagram.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Okay, here is my question. The column has a coded 4% maximum rebar presence right? But in the splice its 8%. So, if 8% is okay during the splice, why is it 4% outside the splice? If it can take 8%, why the 4%?

Am I looking at this wrong? Shouldn't it be 4% or 8% maximum regardless of splice? Just because you double the rebar during a splice, does not mean the columns rebar percentage maximum should increase.

The two values should be the same right? Just the column thickness should be based around the splice percentage and reduced rebar elsewhere.

Is it possible the code is wrong with 4%, 8%? How is the code today?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (AutisticBez (Computer)27 Aug 21 21:24)

So, if 8% is okay during the splice, why is it 4% outside the splice? If it can take 8%, why the 4%?
Somewhere above I read that it was 4% so that at the splice it would not exceed 8%, but that the splice could be staggered to allow more...

#### Quote (R10.6.1.1)

Longitudinal reinforcement in columns should usually not exceed 4 percent if the column bars are required to be lap spliced, as the lap splice zone will have twice as much reinforcement if all lap splices occur at the same location.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer))

++++
Charlie - I scanned well past the Mohr's circles and found only soil/rock(?) strata information for piles and foundations. Nothing addressing aggregates for concrete. I did find what I think is the source for concrete used at CTS - it looks just like many of the pics of crumbles and broken columns and slabs.
It is titled Figure 2-3. Newberry quarry excavation (Paul Bullock 2004; FDOT Public Report) and is found on pdf page 25 of your second reference -https://files.engineering.com/getfile.aspx?folder=...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
acerbic - "tasting sour or bitter."

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

acerbic

You could also just go with “sharp and forthright.”

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)(OP)27 Aug 21 22:12 Quote (Vance Wiley (Structural)27 Aug 21 21:51) Nothing addressing aggregates for concrete. Try the attached:)

Thanks, Charlie - that IS about aggregates.
Takeaway:
Florida uses oolite and Florida limestone for structural concrete.
Memo to self: NEVER get involved in concrete in Florida.

My concern remains about how these aggregates weather under fresh water conditions, acid rain, and coastal environments.
If you see anything about durability of Florida concrete, please let me know.
Thanks again,

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)27 Aug 21 23:23)

If you see anything about durability of Florida concrete,
Well, the first three articles were about "Fiber Reinforced Concrete"
Well...FDOT thinks it's a problem worthy of research...
See Attachment:
(more to come, only one attachment per post (as far as I can tell))
Actually no more to come, one article about using electrical resistance to measure durability, but that's all
Electrical Resistivity of Concrete for Durability Evaluation: A Review

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yeah, but, if 8% max is fine at splice then 8% all the way up is the true max and 4% is merely less rebar?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley)

10.6.1.1 For nonprestressed columns and for prestressed
columns with average fpe < 225 psi, area of longitudinal
reinforcement shall be at least 0.01Ag but shall not exceed
0.08Ag.
R10.6.1.1 Limits are provided for both the minimum and
maximum longitudinal reinforcement ratios.
Maximum reinforcement—The amount of longitudinal
reinforcement is limited to ensure that concrete can be
effectively consolidated around the bars and to ensure that
columns designed according to the Code are similar to the
test specimens by which the Code was calibrated. The 0.08
limit applies at all sections, including splice regions, and
can also be considered a practical maximum for longitudinal reinforcement in terms of economy and requirements
for placing. Longitudinal reinforcement in columns should
usually not exceed 4 percent if the column bars are required
to be lap spliced, as the lap splice zone will have twice as
much reinforcement if all lap splices occur at the same
location.

#### Quote (AutisticBez)

Yeah, but, if 8% max is fine at splice then 8% all the way up is the true max and 4% is merely less rebar?

That is what the code is saying. 8% is fine. But if you need to lap anything you are going to have to double up bars in the lap regions, so to remain below 8% total, you can only have 4% in the sections either side of the slices. In other words: if there are no splices 8% is fine, if there are splices, 4% max either side to remain below 8% at splice.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

A brief but apparently recent drone shot of the CTS slab with NIST at work. Is that L or M9.1/10 where they are drilling?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@MaudStl
It looks to be 3 column lines from south edge-- 12.1 --and about 2 west of pool--between L & M.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (MaudSTL (Computer)27 Aug 21 22:28)

You could also just go with “sharp and forthright.”
I was thinking of the condos, not the comments. I guess I'm the one who's archaic. Sorry.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
I thought (dangerous, I know) that if FDOT was researching in 2017, that maybe there were some results by now. I googled each of the topics, and, sure enough, each had a published paper. I downloaded all four. The one I felt was most applicable (Durability Evaluation of Ternary Mix Designs for Extremely dot dot dot ) is attached below:

If you wish, I would be glad to upload any or all of the following:
1. Performance Improvement of High Early Strength (HES) Concrete for Pavement Replacement Slabs
2. Effects of Blast Furnace Slag Characteristics on Durability of Cementitious Systems for Florida Concrete Structures
3. Development of Calcined Clays as Pozzolanic Additions in Portland Cement Concrete Mixtures

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)(OP)28 Aug 21 16:11)

I was thinking of the condos, not the comments. I guess I'm the one who's archaic. Sorry.

I prefer considering myself 'Vintage' rather than archaic.......

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (MaudSTL (Computer)28 Aug 21 14:20)

A brief but apparently recent drone shot of the CTS slab with NIST at work
Good catch
I'm glad someone is keeping a watch on the research and investigation.
Please like and comment on the video. They can use the support.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (TheGreenLama)

It looks to be 3 column lines from south edge-- 12.1 --and about 2 west of pool--between L & M.

Thank you! I am so used to looking at the plan drawings and counting down from the top that it threw me off to see a different orientation.

#### Quote (SFCharlie)

I guess I'm the one who's archaic.

I think plenty of us are no longer young whippersnappers.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

That drill rig is over L12.1 I believe. That's one of the columns under the pool deck (but not the building) that puncture sheared and remained standing, so I'm not sure why it's of interest.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Sorry, I couldn't help myself...

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I'm not so sure that is a drilling rig. And that blue rectangular object looks to be sized to fit inside the black framework. And that crane is big enough to drop that blue object through the frame for seismic testing of some sort. (just spitballing here.) Maybe getting a baseline on that column or maybe they suspect it started there. I need more pixels.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Nukeman948 (Electrical)28 Aug 21 18:56)

I need more pixels.
Yes, we all do...

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
I managed to squeeze out a few more (no pixels were harmed in the making of this power-pointy)

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The name of the company listed on the side of those trucks would be very useful.
Edit: It doesn't look like ground penetrating radar. Wonder if it's water related?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (That is what the code is saying. 8% is fine. But if you need to lap anything you are going to have to double up bars in the lap regions, so to remain below 8% total, you can only have 4% in the sections either side of the slices. In other words: if there are no splices 8% is fine, if there are splices, 4% max either side to remain below 8% at splice.)

This would be easy if the code or comments had simply stated that column capacity is limited to steel contribution of no more than (some) %Ag. I see a reason for limiting the maximum contribution of the reinforcing.
The key word in this is the word "Lap" which creates a zone with twice the amount of reinforcing. The comment specifically states the purpose of limiting the % of reinforcing is to avoid congestion and facilitate the concrete placement. I can see congestion and small spacings causing poor concrete at a lap section with too much reinforcing - 16% is a lot of the column area and bars will be close together. Some cases require the large aggregate be removed and the first portion of the pour be a slurry with higher cement content. Normal practice is to lap with the bars in contact and the dowels from below oriented to the interior behind the bars above and that helps a bit.
From the commentary "Longitudinal reinforcement in columns should
usually not exceed 4 percent if the column bars are required
to be lap spliced, as the lap splice zone will have twice as
much reinforcement if all lap splices occur at the same location."
I do not read anything there which prohibits a maximum of 8% "at any section" if the bars are not lapped.
The practical workaround is to use splice couplers and keep the bars aligned with the dowels from below. There will no doubt be some discussion of whether the added size of the coupler should be considered as increasing the percentage of reinforcing at the coupler location. I would say technically it does and practically it does not have to, therefore the working % for the column must be less than 8%. This can be fudged by splicing the coupler splices at different heights starting maybe one coupler height above the previous pour. This complicates things and probably should be avoided. BUT if aggregate size allows and mix properties of slump and consolidation efforts are successful, that should be allowed.
The best solution is to avoid highly reinforced columns and just make the column larger, thereby easing the difficulty and increasing the likelihood of success.
Perhaps this has been discussed within the Concrete Design industry and that would be interested to see. Ultimately the EOR is in charge and can decide whether to take advantage of the ambiguity or go conservative and increase the column size.
I would recommend a larger column if a design was closing in on 8%Ag working reinforcing. But then there are architects who want skinny columns.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

In the drone video, the blue box is over the "missing" column in the Tik Tok video.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Surely that "Blue Box" is what we in Oz call a "PortaLoo" ??

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (AusTony2046 (Electrical)28 Aug 21 23:26)

Surely that "Blue Box" is what we in Oz call a "PortaLoo" ??
I admit that was my first thought also, but in this frame from the video the aspect ratio seems wrong.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Could it be a Tardis?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (AusTony2046 (Electrical)29 Aug 21 00:06)

Could it be a Tardis?
Ah,definitely, that's it!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Please somebody put on your best Florida country club outfit. (you know white polo shirt or blouse, golf slacks or skirt, white socks, cross trainers) and call a real estate agent to show you a unit overlooking the CTS. tell them you want to see the view from the balcony. Have them take you over and while your there, take a couple of photos of the tower and the blue thing.
We will all thank you very much!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

What I guess I am trying to say, is that a columns maximum rebar percent should be uniform down the entire length. That if its 8% at the lap, then technically it can take 8% down the entire length.

Or its 4% down the length and the splice is a weak point at 8%.

Someone mentioned staggering the splice, sure, its possible, you have the start and end of the rebar at different points, such that you reduce congestion of rebar at any one point. Its a little complicated, but still possible.

The problem to me, is the splice occurring just above the slabs, and someone deciding they can't fit as much rebar from the slabs through the column due to congestion?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

take a couple of photos of the tower and the blue thing.

There is a live cam but it only shows about 1/3 of what we want to see. When the vid was posted it was already gone. I'm way too busy to keep a close eye on that and there is not much to see most of the time.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

SFCharlie

"the blue thing."

I think those are counterweights or stabilizers for the crane.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

3
Just something I found, looks similar.
They may have been assembling or disassembling the apparatus when the video was made. We may never know its final form.

Dynamic Load Testing is a method to assess pile load capacity by applying a dynamic load to the pile head (usually drop weight in frame) while recording acceleration and strain at the pile head. DLT is a high strain dynamic test which can be undertaken on cast in situ piles when the pile concrete is strong enough to withstand the stresses generated during impact. For preformed piles (eg. steel, timber or precast concrete), testing can be done either during or after installation.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Nukeman948 (Electrical)29 Aug 21 02:50)

Just something I found, looks similar.
I think you may have nailed it.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

I think you may have nailed it.

The definition and the picture came from two different web-sites but from the same search. Couldn't tell you how it works or if it works on an old slab but I'm not getting paid enough for that. At least we have more pixels.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (The problem to me, is the splice occurring just above the slabs, and someone deciding they can't fit as much rebar from the slabs through the column due to congestion?)

You are right on track. And it is the duty of the design engineer to determine that the calculated and specified reinforcing can be installed with the proper separations and developments. That is particularly difficult for structures in seismic zones, where joints may have 4 beams intersecting and a column above and below.
Compression bars at a splice could develop end bearing of maybe 5 to 10 kips - which is disregarded unless one is trying to save his butt.

It would seem to be proper to disregard calculating the column capacity by using the doubled reinforcing (eg. 8%) in a lap splice zone. After all, just above the lap splice the reinforcing drops to half (eg. 4%) and the column loses the stability provided by the slab or beams. This would seem to be a more critical place to check the column, if no frame action has induced moments in the column.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yep; I can imagine that Tardis-like thing being lowered down into that rig as depicted in Nukeman's photo. Good work!

Here's a slightly-less potato-ey grab from that drone footage...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Charlie - you are the go-to guy when it comes to sources and references.
I cannot locate an on-line source for an ACI 318-77 code. Can you find one? I have looked for more than 4 hours.
Does anyone on this thread have one and could copy the Column Design section, which is Chapter 10 in the -14 version, and post it here, please?
I would like to verify the 4%/8% issue. If the maximum allowed reinforcing was 8% for splice zones in the ACI 318-77 version several columns are/were not code compliant at the splice zones.
If that is the case, special measures were necessary to ensure dense and well conslolidated concrete at those zones, and it seems the concrete for this project had little special attention.
The possible consequence would be low density or incomplete consolidation of the concrete, and possibly leaving voids and rock pockets at some locations. Most serious locations would possibly be at the top of the pile caps and locations where salt water could collect from whatever source - winds off the ocean, wet tires, or underground water.
Thanks,
EDIT ADD: Drawing sheet S-11 references ACI 318-72..ACI 318-77 should have been in effect when the design was performed.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The gadget is certainty not ground penetrating radar, and is way too big for a seismic testing device. The dynamic tester idea looks good to me. The van on the near side of the site in badged Cone Tec or Conc tec, if that rings bells with anybody.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yes, thanks for that explanation. To me, also, it feels like a bad idea to attempt to design columns as small as possible. I mean, you have a set percentage for the rebar to concrete ratio. As your column shrinks, as does the content of rebar.

When I was referring the vehicle impact data, it was obvious that only a little bit more thickness of the columns was enough to completely prevent the issue. If an extra inch of concrete column thickness was enough to save nearly a hundred people from dying, isn't that worth it?

If we added up the total cost of an extra inch calculated into every dimension of the building, and that cost spread over 40 years. What amount are we talking about? Is the lowest common denominator acceptable here?

The code says this, so we won't do anymore then the code? Like I am sure that the code isn't there to put the bare minimum into your building. How safe do people feel living in a condo where only the bare minimum was put in to satisfy the "code"? Maybe the code should be set at a 4x amount that makes it super impossible for buildings to ever fall over ever again?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Nukeman948)

I believe you are correct. Lying in bed last night that was another option that came to mind. I've never seen this done, but this would be something entirely plausible. Below is video of an operation. I can't vouch for all the info presented. https://www.youtube.com/watch?v=ZWN5dO1U1ms Obviously they need to set up above an existing pile cap. Another pile test option is a static test.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (To me, also, it feels like a bad idea to attempt to design columns as small as possible.)

You do, within reason; columns are non useable floor space. You keep the same column size for several floors changing the amount of reinforcing and you can change the concrete strength, too. You want to keep the same concrete strength for all columns on a given level. I haven't designed a multi-storey concrete building for a couple of decades, but that's the way it was done; I assume it's still done the same for economy.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (TheGreenLama)

I believe you are correct.

And yet I am not 100% convinced on my own theory. From your video it says the minimum pile exposure is 2 times the diameter. They may have found a way to get usable data even with a slab that would distribute the the impact over multiple piles or maybe they are using DLT equipment in a different manner or for a different purpose. I check the live cam at least once on most days if I have time, and never saw them while they were there. I'm pretty sure they only tested one or two locations if that means anything.

Edit: Live cam is missing in action right now, maybe they know I'm watching!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)29 Aug 21 08:26)

I cannot locate an on-line source for an ACI 318-77 code. Can you find one?
my google search was "ACI 318-77"

ACI 318-77 Topic - American Concrete Institutehttps://www.concrete.org › topicsinconcrete › topicdetail
JOURNAL Articles ON ACI 318-77. Behavior and Design of Multistory Building Frames of Unbonded Post-Tensioned Concrete. Publication: Journal Proceedings
People also search for
aci 318-77 pdf
aci 318-89
aci 318 history
aci 318 versions
reinforced concrete
aci
What is the current version of ACI 318?
I clicked on:
INFORMATIONAL RESOURCES ON ACI 318-77
on that page, I clicked on:

#### Quote:

Standards & Documents (1)
on that page I found:

#### Quote (STANDARDS, PRACTICES AND MANUALS ON ACI 318-77 318 Historical ACI Building Code Requirements (1908-2005) VIEW ALL DOCUMENTS ON ACI 318-77 »)

I clicked on:
318 Historical ACI Building Code Requirements (1908-2005)

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Nukeman948 (Electrical)29 Aug 21 15:21)

Edit: Live cam is missing in action right now, maybe they know I'm watching!

Maybe they don't know we are watching?
Let YouTube and Them know you care! Thanks

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

2
Related to the drone video showing test rig and blue drop mass, here's an interesting description of the information gathered from Dynamic Load Testing (DLT):

The narrator speaks of "drilled shafts" (a terminology not much used in this thread).

Drilled Shafts: Elements formed by creating a drilled hole into which structural steel and concrete is cast or placed.

Driven Piles: Foundation support typically using steel or precast concrete elements driven into soil with impact or vibratory methods.

I think that the Franki piles in use at CTS are sort of a hybrid, since their installation involves both wet concrete placement and driving.

Regarding ConeTec (as spotted by AusG), I found no specific mention of DLT on their website, but they are clearly specialists in doing geotechnical site investigations.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Vance, just to confirm I agree completely with what you are saying re: reinforcement %'s. Not sure if you thought I didn't, or it just came across like that on the interwebs. I was merely trying to elaborate on the practicalities for AutisticBez's sake.

I don't do concrete design, but I suspect if I was, and I knew that a) I had to lap bars and b) the maximum reinforcement % was 8%; then I would design everything I knew had to be lapped with 4% reinforcement so it wasn't an issue / didn't matter where the splices ended up being.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

you almost never design columns for the max 4% reinforcing... generally 2-1/2% and then go up to about 4% and then you change column size.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@Nukeman948,

For test to be effective I would think they would have had to chip out fdn slab to expose a lone Franki pile (No comment of effectiveness of PDA on Franki piles). And it is likely that they are working in that area simply because it is away from the collapse event. Piles near collapse may have been damaged.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)

Thanks, Charlie. You ARE the master of drill downs in my book.
I was able to get to

#### Quote (318 Historical ACI Building Code Requirements (1908-2005))

and now I just need to sell my house to cover the cost and I will be good.
In today's code, using lap splices, the max reinforcing in a column is 4% (as I interpret the code) because the lap splice zone is limited to 8%.
That may not have been the case in 1980.
In my mind I had thought the max reinforcing was 4% and the purpose was to prevent brittle and abrupt failures.
Today we have products which can flow and maintain strength and could be used in congested areas - there is a minimum limit dimensionally of course, and the cost rises. Another 2 inches on the column dimension or an extra 1000 psi on concrete strength would be less expensive, I think.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (KingBobo (Mechanical)29 Aug 21 16:56)

Regarding ConeTec (as spotted by AusG), I found no specific mention of DLT on their website, but they are clearly specialists in doing geotechnical site investigations.
I noticed:
Drilling, and:
geophysical-testing
Including
MULTI-CHANNEL ANALYSIS OF SURFACE WAVES
So, maybe, drop the weight, and record the echoes???)

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (RandomTaskkk (Structural)29 Aug 21 17:02 I was merely trying to elaborate on the practicalities .)

I appreciate that and I agree with you there.
This ball of string has gotten away from me and I am trying to collect the ends to prevent leaving bad information here.
Thanks for the help.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

For those currently debating % steel and lap splices let me add my two cents.

Staggered lap splices are common.

Couplers are sometimes given as an option for contractors. I have a sense, though, that these are a costly option.

Using couplers for outside/perimeter column bars may be impacted by two things: maintaining minimum concrete cover (as a coupled bar now has an increased diameter); interference w/ the shear/confinement steel. You always want to situate your column steel as close to the edge as possible, and shear steel interference w/ coupled bars may impact the use of couplers.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)29 Aug 21 17:48)

and now I just need to sell my house to cover the cost and I will be good.
ACI 318: Building Code Requirements for Reinforced Concrete
It's Big
(finally got it to open, it's the 1995 version.)

edit: one may buy a used hardcover on Amazon for $120 +$4 shipping

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)29 Aug 21 17:48)

and now I just need to sell my house to cover the cost and I will be good.
Attached is a .pdf of chapter 10.6. It is not searchable, but it is small.
If there are other chapters you would like, just ask...

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (it's the 1995 version.)

My earliest edition is the '63...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@Vance Wiley,

Found a PDF online that is labeled as a 1980 "Technical Release" for use by the USDA that is supposedly based on ACI 318-77. User beware.
https://directives.sc.egov.usda.gov/OpenNonWebCont...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)(OP)29 Aug 21 19:32 Attached is a .pdf of chapters 10.7. 10.8 Again it's not searchable, but small.)

Charlie - thank you so much - but - your clip starts at 10.7 and in the ACI 318-19 the the % reinforcing is Chapter 10.6. I hate to wear out my welcome, but if it is not too much trouble and if 10.6 is available to you - -please?
Many thanks, and an old phrase "Much Obliged".

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

Maybe they don't know we are watching?
Let YouTube and Them know you care! Thanks

I would normally agree with letting them know we like their content but this is not a youtube live cam. It is a NEST cam that is owned by the same people that have the drone video but they do not share a link for the NEST cam on their youtube page. If they want it hidden, I'm not going to draw extra attention to it. Some people really want to restrict sharing info with other people. I think the facebook page I was on is theirs also and they are searching for spies that are stealing their info and not giving credit to them. Something about a "fake youtube engineer" making videos with their research.

This post will self destruct as soon as you finish reading it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)29 Aug 21 20:39)

if 10.6 is available to you

#### Quote (SFCharlie (Computer)(OP)29 Aug 21 19:11)

Attached is a .pdf of chapter 10.6. It is not searchable, but it is small.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (TheGreenLama (Structural)29 Aug 21 20:24 @Vance Wiley, Found a PDF online that is labeled as a 1980 "Technical Release" for use by the USDA that is supposedly based on ACI 318-77. User beware)

Thank you.. I scanned thru to the end and revisited the first 60 pages -I did not find anything addressing columns or amount of reinforcing in columns.
I do appreciate the effort. And I will beware.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

This was interesting to listen to, maybe start at around 20:00

August 25, 2021 Building Membership Council Governing Committee meeting

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

MASW
Nice thought but nope. I have done some Multichannel analysis of surface wave MASW for geotech in limestone terrain and all you need is a FBH and someone's big dumb nephew to swing it. All that heavy hardware would just complicate things. Also I'm not seeing strings of geophones laid out. MASW would be the correct seismic technique for this job so maybe we'll see that later.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie (Computer)(OP)29 Aug 21 20:52 Quote (Vance Wiley (Structural)29 Aug 21 20:39) if 10.6 is available to you)

You are a hard man to keep up with, Charlie.
You had already sent 10.+. Your clip of 10.7 and 10.8 carries over to 10.9 and that addresses maximum reinforcing in compression members ( columns).
It clearly states minimum As is 1%Ag and maximum As is 8%Ag. The comment recommends As max of 4% if splices are lapped.
Note that it is a recommendation. So if the columns at CTS have 6% reinforcing that was not a code violation - just ignoring a recommendation. And is not permitted in current codes, practices, or recommendations by several Structurals on this forum.
I can put this to rest now. I will not use more than 4% steel in a concrete column.
Thanks, everyone.
WAIT !!
Charlie - were the clips you sent from a 1995 edition of ACI 318? If so that leaves me wondering how the 1977 edition addressed this. No sleep yet - - - disregard prior comments herein.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (AusG (Petroleum)29 Aug 21 22:16)

I'm not seeing strings of geophones laid out
Nop, Neither do I.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

This paper Pile capacity using dynamic analysis has a reasonable explanation of the dynamic pile test. It is covered by ASTM D4945 Standard Test Method for High-Strain Dynamic Testing of Deep Foundations.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)29 Aug 21 22:19)

were the clips you sent from a 1995 edition of ACI 318? If so that leaves me wondering how the 1977 edition addressed this.
1. I don't know.
2. the posts upstream are from the 2014 version
3. I don't think it has changed much?
4. Chapter 8 is labeled:
"ANALYSIS AND DESIGN GENERAL CONSIDERATIONS ......... 318-77" <- I don't understand this?

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Note that it is a recommendation.)

More than a recommendation... those that 'Be' will rain down h*llfire and brimstone on those that mess with it.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

@FacEngrPE... thanks for the link; it's good.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (dik)

FYI
Was your post from the 1963 code, it sure looks familiar; like the code that we used at university.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (apper.42 (Structural)30 Aug 21 01:52)

Was your post from the 1963 code
If it was, It hadn't changed a whit by 1995
edit: Nop, same hand written note (page 113, top of right hand column "UBC ZONES 3.4") in my 1995 and DIK's chapter 10

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Also, based on the drawings, what % were these columns set to be?

I would be interested in knowing about the columns that failed.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I just looked back over the 1979 column schedule. (Item 4 at https://surfside.one/public-records-search/). Column type D (16"x16" w/ 12 of #11 rebar) has 7.3% rebar at basement level and column G (14"x18" w/ 10 of #11 rebar) has 6.2%. Column type L has 5.3% at the basement. Those are the most packed. These may not be as built but it was the only column schedule I could lay my hands on. I know the over-packed rebar idea has come up before, sorry if this old news.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Just a thought on applicability of Dynamic Load Testing of CST Franki piles. I'm not familiar w/ this testing method, but to get useful results don't you need a fair degree of precision in both the pile length and it's cross sectional area? Franki piles have a bulb of unknown size at base. And do we have as-built pile lengths for CST?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Traveled to the east coast last week, and could not help but notice the massive shear walls in the parking garage under the Target store in King of Prussia, PA. Might not have noticed them two months ago, but they sure stand out now. This picture shows 3 of them, but there were probably 8 overall.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Aaaaaaaannnnddddd…they’re off! The Miami Herald says that live bidding on 8777 Collins Ave. will be scheduled. “Surfside’s Champlain Towers South site on the market. Live bidding planned.“

>>>>>Edit: More late-breaking news.

South Florida Officials Hold Discussion Regarding Safety Improvements Following Surfside Condo Collapse

Museum Preserves Surfside Memorial Wall for Building Collapse Victims

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I expect the new design will emphasise solidity and permanence, and stay within the limits of local materials and technology. Link

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

SFC... do you have it as a *.pdf?

thanks...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I have the 1995 version in PDF FORMAT of the ACI-318-77 spec, which is actually called ACI-318-95.

Let me know if anyone wants it. I searched high and low and cannot find anyone with the "77" version who doesn't want $200 for a stinking PDF! Also, I uploaded a video the other night where I added my graphic overlay of the parking garage over NIST's video of the empty garage floor "hockey rink", to aid visually what is going on at the site, and identify where ground zero is. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 AusG, and that isn't at the splice right? Which means at the splice, this could be even worse? ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) #### Quote (Jeff Ostroff (Electrical)30 Aug 21 22:48) I have the 1995 version in PDF FORMAT of the ACI-318-77 spec, which is actually called ACI-318-95. I had already put a link to that above. #### Quote (SFCharlie (Computer)(OP)29 Aug 21 18:28) Depending on your PC, you might try downloading the .pdf: ACI 318: Building Code Requirements for Reinforced Concrete It's Big (finally got it to open, it's the 1995 version.) ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 Here is the overlay I made on top of a screenshot from the NIST drone flyover, showing the locations of the important columns, plus a tiny embedded screenshot of the tourist video showing approximately where they were seeing all the debris landing on the garage floor. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (AutisticBez) and that isn't at the splice right? No, that is the straight column schedule, but just for the basement level. The steel decreases rapidly upwards. IDK how often a splice is required but yes, a splice near the basement level would be very crowded. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 too close to KFC? Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 Ok here's a question. Once the slab has collapsed as per the tiktok and survivor accounts it is no longer pulling catenary-wise on the columns. Whatever lateral damage can be caused by the falling slab is done by that point. Is it more likely that the building survives those next 14 minutes with one or two columns gone, or that the extra buckling in unsupported columns could bring it down 14 minutes later? ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 AusG, first it was maybe only 5 to 7 minutes from deck collapse to building collapse. Most likely the falling 12"x16" column M11.1 weakened or crippled the 16"x16" M9.1/M10 via yanking on the beam connecting them as the skinnier column was destroyed by the deck collapse, and shown missing in the tourist video. I think that the smaller column severely damaged the 16"x16" to the point that it made that now-weakened and de-rated 16"x16" column a few minutes later begin to buckle and crumble, now that they are no longer rated to do the job they have been doing up to this point. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (AusG and Jeff Ostroff) The deck collapsed at 1:15 AM or so and the building collapsed at 1:22 AM, so about seven minutes elapsed between those two events. During that time witnesses say the building was shaking and rumbling. Here’s the CTS Collapse Witness Statement Timeline for your reference. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 It may have been with the collapse of the deck that the deck pulled the tower supporting columns as shown in the one animation and this precipitated the tower collapse. Due to possible underdesign and definite criminal lack of maintenance the building collapsed. Whatever triggered the event is really immaterial. It was the straw that broke... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I misremembered the time interval, my bad. Dik the gap, whatever time it is matters though. Was it a time gap while the building stood with missing columns, or stood before the columns buckled and quit? Jeff's sequence of deck-column-beam-column-total collapse is interesting. I noted in various pics there is some rubble under that "C" of short beams that was left uncollected for some time, so it was not exactly the first thing to fall in the main building, although most other rubble looked later again. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I'm not so sure that either 10 seconds or 10 minutes has any bearing... the stage was set; it could have been Lorenz' butterfly. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I'm on record here agreeing with that basic point: it was poised to fall by this point. I'm just noting that once the deck is down there is no more catenary pull, so either it took another 7 minutes to (fail to) load shift with missing column(s) or 7 minutes to buckle those columns, and I was wondering from our SE contingent which was more likely. It may be an unanswerable question and so be it. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I have always had a problem with the term "missing column". Even if the concrete completely crumbled wouldn't there still be rebar that would buckle? There was rebar coming up through the slab and the splice should have been above the next slab and I can't see all that rebar getting sheared off or pulled out and the column simply falling over. Of course rebar can be sheared off like at the shear wall as the building fell, but that is a different situation from a column getting bumped by a car or catenary forces from the pool deck. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) A link in the article, that Maud posted just above: #### Quote (MaudSTL (Computer)31 Aug 21 13:32) had slipped past me. It has nice 3d perspective art for the floor plan, with location of the victims, and tears. A vertical neighborhood: Floor-by-floor look at the lives lost and dreams shattered by Florida condo collapse (maybe Maud will share the magic of how to make a link to bypass the firewall? Thanks) ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I don't know if you folks have heard over the last few weeks but the mayor of surfside has been whining in the news for a few weeks about how Miami Dade PD won't allow him or his engineering company World-renowned civil engineer Allyn Kilsheimer who investigated the 9/11 Pentagon attack and the FIU bridge collapse, to enter the collapsed condo property at all. Miami Dade police have been keeping that place solid nobody goes in or out. And I listened in the other day to a Surfside Commission meeting where the entire Commission wasted 1/2 hour of time bickering back and forth trying to figure out why won't they let us in blah blah blah. These people are totally clueless they don't realize that they are the subject of a criminal investigation and I think their heads are buried in the sand on this one. And the reason why they are the result of a criminal investigation is because like we've mentioned before here on the forum, all sorts of records are missing from the city! And, they don't know if missing records are due to that former city inspector Ross Prieto who had the keys to the warehouse under his name, whether he is the reason they are missing but right now everybody is suspect including anybody that the city would hire even though Alan has a very good reputation in the business. That being said, Alan did visit the sister property, the Champlain towers north which has almost the same floor plan, and he did take all sorts of core samples there and I guess we're waiting to hear back from the results of that, but so far he feels that building is not in any danger of collapsing. the scuttlebutt I had heard from over the years was that maintenance was completed in a timely manner in the north towers, as that homeowners association was more on the ball and when things broke down they fixed them there not let needed repairs sit there in fester for years. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) I have processed ACI 318-56 into two smaller searchable .pdf files, Be careful with formulas, they have been thru a tortured process Adobe converted pdf to OCRed Word, I manually remove the shadows of the "gutter" between the pages of the book, Word saved as .pdf. (only one attachment per post - Part 1 SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) Part 2 I have processed ACI 318-56 into two smaller searchable .pdf files, Be careful with formulas, they have been thru a tortured process Adobe converted pdf to OCRed Word, I manually remove the shadows of the "gutter" between the pages of the book, Word saved as .pdf. (only one attachment per post - Part 2 SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) If there is a particular page, image, table, or formula etc. in ACI 318-56, that you wish to see the original, that's easy. Just Identify the page clearly, and I'll post its image... SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (SFCharlie) …nice 3d perspective art for the floor plan, with location of the victims, and tears. Here’s an archived version. This piece was never updated with final status info…it shows people as Missing who have been recovered Deceased. A vertical neighborhood: Floor-by-floor look at the lives lost and dreams shattered by Florida condo collapse ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 2 Archiving the Contents of a URL Pros A utility at archive.today takes a snapshot of the contents of a URL and stores it. This has several benefits, e.g. developing news stories can be archived multiple times as the story unfolds and information on the URL is updated. It will also archive an article that is on a site with a “number of free articles” counter on it. It will retain the archive even if the original URL is taken down. Cons Archive.today will not archive an article behind a true firewall requiring a login, e.g. WSJ, etc. Sometimes videos within the content will play and sometimes they won’t. Embedded hyperlinks may or may not work. Interactive graphics don’t work interactively…they will be static graphics. Steps 1. Copy the URL you want to archive 2. Access archive.today 3. Paste the URL in the “I want to search the archive for saved snapshots” field and click Search 4. Complete the CAPTCHA 5. If the archive DOES contain one or more snapshots, select from the existing options and then copy its URL 6. If the archive does NOT contain existing snapshots, click the hyperlink “Archive this URL,” click Save in the “My URL is alive and I want to archive its contents” field, wait for the archive to be written, and then copy the URL ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 Are all of these ACI documents being circulated in their entirety here not copy written material? ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 AusG, So the columns that failed were overcrowded with rebar? This making them weaker then they should be? Its clearly out of code right? What about the connection point with the beam under the planters? Also, exactly where does the splice occur? Is the splice just above the beam? ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) When I was traveling regularly for business, Almost everywhere I stayed, had copies of USAToday. Maybe because their audience consists of middle class vacationer and also business men, they seem to steer away from extremes. Even today, I find myself read articles on my many diverse interest in USAToday. I find them well written, well researched, and factual. I recommend that you subscribe as I have. Here is a sample of their work: Beyond the firewall A link in the article, that Maud posted just above: #### Quote (MaudSTL (Computer)31 Aug 21 13:32) had slipped past me. It has nice 3d perspective art for the floor plan, with location of the victims, and tears. A vertical neighborhood: Floor-by-floor look at the lives lost and dreams shattered by Florida condo collapse SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) #### Quote (Spartan5 (Civil/Environmental)31 Aug 21 18:48) Are all of these ACI documents being circulated in their entirety here not copy written material? My very first post was a link the the ACI's own site. I did provide a link to the '95 document that was already publicly visible and searchable on the web. I also posted a link to Amazon's offers where one could purchase used editions. This is common in reviews of copyrighted material. I believe my other posts have been links or excerpts. SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (AutisticBez) rebar I just looked at the column schedule, found a published table of x-sectional areas of standard rebar, and did the arithmetic. It stands to reason splices, beam and slab attachments will all increase crowding. One of the youtube analyses of the building raised this, and it was discussed here a few threads ago by people with much more knowledge than me. If you are keen you should look back some. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (Nukeman948 (Electrical)31 Aug 21 12:26 I have always had a problem with the term "missing column". Even if the concrete completely crumbled wouldn't there still be rebar that would buckle?) There certainly should be dowels from the pile cap or column below and the remains of a column caught below most of the debris from the slabs above. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (AutisticBez (Computer)31 Aug 21 19:33 AusG, So the columns that failed were overcrowded with rebar? This making them weaker then they should be? Its clearly out of code right? What about the connection point with the beam under the planters? Also, exactly where does the splice occur? Is the splice just above the beam?) Excessive reinforcing at splices inhibits good concrete in that region, possibly leaving rock pockets and poorly consolidated/compacted concrete. Do not know about the beam to column joints or beam to beam joints. That is typically easier to use a vibrator and improve the density of concrete there. Splices in the columns are at the top of the pile caps, and top of each floor slab. Details for this are on sheet S-3 (pile caps) and S-11, columns. EDIT ADD: Subsequent posts address rebar crowding - I would add that it has been suggested here that 3% to 3.5% is a practical limit. I agree, and suggest the extra concrete be used to provide more cover for the reinforcing, thereby also providing enhanced protection from corrosion, particularly important in coastal environments. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (moon61) I think it would qualify as fair use. https://www.copyright.gov/fair-use/more-info.html I get fair use. No doubt I push the boundaries of it too in my postings on the internet. But per the information you shared. I don’t think that posting/sharing or hosting (in the case of files uploaded to engineering.com’s servers)whole documents constitutes fair use. Two of the factors considered in evaluating fair use: #### Quote: Amount and substantiality of the portion used in relation to the copyrighted work as a whole: Under this factor, courts look at both the quantity and quality of the copyrighted material that was used. If the use includes a large portion of the copyrighted work, fair use is less likely to be found; if the use employs only a small amount of copyrighted material, fair use is more likely. That said, some courts have found use of an entire work to be fair under certain circumstances. And in other contexts, using even a small amount of a copyrighted work was determined not to be fair because the selection was an important part—or the “heart”—of the work. In this case, complete works of different ACI standards are being distributed. In some cases, enhanced even to make it searchable and eliminate annoying artifacts left over from the stealing process. #### Quote: Effect of the use upon the potential market for or value of the copyrighted work: Here, courts review whether, and to what extent, the unlicensed use harms the existing or future market for the copyright owner’s original work. In assessing this factor, courts consider whether the use is hurting the current market for the original work (for example, by displacing sales of the original) and/or whether the use could cause substantial harm if it were to become widespread. It would seem this would certainly apply to the current code. Maybe less so to the older versions. Though, if ACI still sells them (or sells a higher quality (e.g. searchable version), it seems apparent it’s harming the market value. Otherwise it would seem there would be entire libraries of these and other documents (like ASTM specs) just existing out there in the public domain. I also don’t think that “I’m just sharing something that someone else stole” is a defense that a Professional Engineer should use. But maybe that’s just me. Maybe the ACI documents are intended to be free. In which case I’m out in left field. But I always thought that charging for these standards was the means of recouping some of the cost for developing them. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) #### Quote (MaudSTL (Computer)31 Aug 21 23:28) A structural engineer in Broward doesn’t want to update the current code at this time. #### Quote (Brittany Wallman - South Florida Sun Sentinel) "The official, Dan Lavrich, said there’s no evidence to support changes – no proof that poor maintenance played a role in the tower’s collapse, no data showing climate change affects a building’s structural integrity, and no justification for requiring earlier safety inspections." . . . "If Broward ends up alone in seeking changes to the safety inspection program, it will be up to Lavrich’s 13-member Board of Rules and Appeals to vote to recommend it to the Florida Building Commission." Nop no flooding here: Thursday Night's Rain Caused Street Flooding On Miami Beach Aug 13, 2021 nor here: Miami Beach areas already flooded as Fred approaches Florida Aug 13, 2021 SF Charlie Eng-Tips.com Forum Policies ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 #### Quote (MaudSTL) I can think of several things a diligent county could do right now, so I don't buy "nothing to be done", but I'm not sure what specific climate or sea level clauses should be entered right now in a building code as a result of CTS. Sea level rise is a foreseeable hazard for shorefront property generally so it should be mentioned. Is it not already? ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) #### Quote (Spartan5 (Civil/Environmental)1 Sep 21 00:43) I have deleted the two of my posts I found contained whole documents. I do maintain that: 1. Posting a link to their site with instruction to find their publications helps them. 2. Exposing engineers to the existence and relevance of their codes helps them. 3. A link to "stolen" ACI-318 is no different than finding that link in a google search. 4. The "clean-ups" were put thru Adobe OCR which corrupted the formulas, the heart of the work. So go buy a copy ACI Standard Building Code Requirements for Reinforced Concrete (ACI 318-63)by ACI Committee 318$120.69

Hardcover · Used, Good
Only 1 left in stock - order soon.
Shipped from: Friends of Jefferson Public Library

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

I have deleted the two of my posts I found contained whole documents.
I do maintain that:
1. Posting a link to their site with instruction to find their publications helps them.
2. Exposing engineers to the existence and relevance of their codes helps them.
3. A link to "stolen" ACI-318 is no different than finding that link in a google search.
4. The "clean-ups" were put thru Adobe OCR which corrupted the formulas, the heart of the work.
Number 3 was the issue. Like I said, I don’t think posting links that circumvent the copyright of the standard, or even the instructions on how to find them for free, is very ethical. But that’s my opinion. Seems straightforward to me though.

The ACI sells a thumb drive with every version and supplementary documentation from 1908 to 2005 (fully searchable) for $200 here: https://www.concrete.org/store/productdetail.aspx?... Including: #### Quote: 1908- NACU Report of the Committee on Laws and Ordinances 1910- NACU Standard No. 4 Standard Building Regulations for the Use of Reinforced Concrete 1920- American Concrete Institute Standard Specifications No. 23 1927- Reinforced Concrete Building Design and Specifications 1936- Building Regulations for Reinforced Concrete (ACI 501-36T) 1941- Building Regulations for Reinforced Concrete (ACI 318-41) 1947- Building Code Requirements for Reinforced Concrete (ACI 318-47) 1951- Building Code Requirements for Reinforced Concrete (ACI 318-51) 1956- Building Code Requirements for Reinforced Concrete (ACI 318-56) 1963- Building Code Requirements for Reinforced Concrete (ACI 318-63) 1963- Commentary on Building Code Requirements for Reinforced Concrete (ACI 318-63) 1971- Building Code Requirements for Reinforced Concrete (ACI 318-71) 1971- Commentary on Building Code Requirements for Reinforced Concrete (ACI 318-71) 1973- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-71) 1974- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-71) 1975- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-71) 1976- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-71) 1977- Building Code Requirements for Reinforced Concrete (ACI 318-77) 1977- Commentary on Building Code Requirements for Reinforced Concrete (ACI 318R-77) 1980- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-77) 1983- Building Code Requirements for Reinforced Concrete (ACI 318-83) 1983- Commentary on Building Code Requirements for Reinforced Concrete (ACI 318R-83) 1983- Building Code Requirements for Structural Plain Concrete (ACI 318.1-83) and Commentary 1986- Building Code Requirements for Reinforced Concrete (ACI 318-83) (Revised 1986) 1986- Supplement to: Building Code Requirements for Reinforced Concrete (ACI 318-83) and (ACI 318M-83) and Commentary 1989- Building Code Requirements for Reinforced Concrete (ACI 318-89) and Commentary (ACI 318R-89) 1989- Building Code Requirements for Structural Plain Concrete (ACI 318.1-89) and Commentary (ACI 318.1R-89) 1992- Building Code Requirements for Reinforced Concrete (ACI 318-89) and Commentary (ACI 318R-89) (Revised 1992) 1992- Building Code Requirements for Structural Plain Concrete (ACI 318.1-89) and Commentary (ACI 318.1R-89) (Revised 1992) 1995- Building Code Requirements for Structural Concrete (ACI 318-95) and Commentary (ACI 318R-95) 1999- Building Code Requirements for Structural Concrete (ACI 318-99) and Commentary (ACI 318R-99) 2002- Building Code Requirements for Structural Concrete (ACI 318-02) and Commentary (ACI 318R-02) 2005- Building Code Requirements for Structural Concrete (ACI 318-05) and Commentary (ACI 318R-05) This site sells it at a slight discount for$178.65

By the time you’re done with it, that memory stick will certainly be treasured memento that holds a place of esteem alongside your other well-worn texts =)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote ((MaudSTL (Computer)31 Aug 21 23:28) A structural engineer in Broward doesn’t want to update the current code at this time.)

It is best to proceed with caution. You don't want to put the cart before the horse. We don't know yet what happened, so we can't prevent it.

However, it appears that the building was built too low to begin with, which cannot be blamed on sea level rise, but you can start by building well above the current water table.

120 Years ago or so, the city of Miami was quarantined because of yellow fever. At http://digitalcollections.fiu.edu/tequesta/files/1... you can read an interesting account of how it was dealt with. It helps to read it using some historical perspective. A lot of very costly things were done but the mosquitoes weren't quarantined. You don't want to repeat mistakes. There is no substitute for knowledge.

In the epilogue, the Reed Commission is mentioned. That would be Major Walter Reed after whom the hospital was named when he died of a ruptured appendix.

Some of the treatments for yellow fever:

#### Quote (There was a fellow with us... a big strapping man. Suddenly he had a terrible chill. We immediately rushed him to his room, got a bucket of boiling water in which we placed his feet, put him to bed with several blankets over him, a mustard plaster on his stomach and cracked ice around his throat and at the top of his head. In a few minutes he was delirious. It took six of us to hold him in bed. He would yell... you could hear him in Cuba. The six of us heldhim in bed for five hours until he finally dozed off from weakness.)

We need to get this right. In the meantime, more inspections can't hurt.

EDIT: It seems as if the building didn't meet code when built and the code has been updated since then, so further updates would not be specific to this tragedy. Since this is not my area of expertise, does code specifically address repairs? It seems to me that more focus needs to be made on all the repairs that were made to the pool deck. How are such repairs regulated?

(OP)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (IEGeezer (Industrial)1 Sep 21 04:22)

At what point does someone need to step in and say that you can't treat a slab like "my grandfather's axe: I've replaced the head twice and the handle three times"?
After what we know about the structural slab delaminating at the top reinforcement, I think that the only real fix would be to replace the entire slab? But your question about who makes that call, is a valid question.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Vance Wiley (Structural)1 Sep 21 17:38)

@Charlie - It could be a good thing to have all these in the library for this forum - while they are free.
In the mean time:
Resistance of Flat-Plate Buildings against Progressive
Collapse. I: Modeling of Slab-Column Connections

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Nice Model and article from NY Times titled "The Surfside Condo Was Flawed and Failing. Here’s a Look Inside."

https://www.nytimes.com/interactive/2021/09/01/us/...

Edit: Warning for some, No mention on Top First.......

#### Quote (SFCharlie (Computer)(OP)1 Sep 21 22:30)

Thank you for posting that particular paper! It appears my attempted post of this paper was a failure!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

According to the excellent timeline from MaudSTL (Computer):

Before 1:10 AM, there were "knocking" noises.

At T minus 12 (1:10 AM):
In 111, Sarah (office), Gabe (kitchen), and Chani Nir (shower) hear a loud crash, as if "a wall collapsed" in the condo above.

In the lobby, Shamoka Furman hears a loud sound that seems to come from the elevator, although the elevator throws no alarms.

At 1:15 AM, the deck collapses:

In the lobby, Sarah Nir and Shamoka Furman hear a "big boom." Sarah runs to the window to see "all the garage has collapsed...:"

In 111, Gabe and Chani, hear a loud crash.

In the elevator between the garage and the lobby, Nicolas Vazquez and Gimena Arcadi hear and fell the collapse.

Other than the Nirs, I believe only Ileana Monteagudo in the x11 stack survive. Ms. Monteagudo wakes up after the deck collapse.

What if, one of the balconies between the red lines below fails and falls, thus collapsing the pool deck. I hate to bring up the "falling object" theory again, but I am struggling to explain the "knocking" noises and the "wall crashing" before the deck collapse. What if the balcony was falling slowly, until it fell against the building, hanging by a thread and then collapsed to the pool deck, collapsing it and precipitating the rest? Just another thought.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Expanding on the falling balcony idea - if a balcony collapsed slowly, pieces of it or items falling from it might account for the knocking noises?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

If the deck started to fail progressively at the construction joint near the pool first, unzipping almost, it would account for knocking noises. Punch, sag, pull, collapse, punch, sag, pull, collapse, etc. until it got to the parking area, then a larger punch, sag, collapse (BANG) and pull before the columns give way and bring the whole building down.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The problem with the falling balcony idea is that it starts with an idea in search of evidence. That is the type of flawed thinking that gets us looking at fuzzy pictures and seeing A/C units and tar-paper rolls when they just are not there.
A good theory always starts with evidence and works towards a viable explanation without confirmation bias.
It could be correct but the balconies are not simply glued to the side of the building but are a cantilevered part of the floor slabs with lengths of rebar extending far into the slab. I don't see them having any more chance of failing in a way that would trigger a collapse than other theories that have much more evidence and seem more likely.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I'm thinking the knocking noises could also be grab-and-release of surfaces grinding under load - say rebar prying out, or a crack or joints moving. The same process as creates creaking but more periodic. say: Pool deck progressive sag with catenary pull on the columns (could that find a fulcrum on first floor slab, stressing the second floor?), knocking, Nir's first collapse "above", pool deck gives up completely, unsupported and wracked columns buckle, general collapse of first section.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Thanks, IEGeezer.

Also keep in mind that the knocking sounds went on for over two hours, and maybe longer. Chani Nir (111) heard them starting at 11 PM when she got home. We have no idea if Shamoka Furman or anyone else heard the knocking sounds in the lobby, or at what time the sounds actually started. So that 2+ hour duration would tend to favor of the slo-mo deck collapse pulling hard enough on a weak column idea over the balcony collapse idea.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I think the problem with the falling balconies is that when I see video of the security camera from 87 Park next door, as the condo starts to collapse, it looks like all the balconies are accounted for. I don't see anything out of place.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Regarding the elevator noises, maybe knocking noises.. someone had mentioned before that the concrete blocks that made up the shaft walls, if the elevator shaft walls were damaged the blocks would fall down onto the elevator cars, thus creating 'noises from above'.

Good view of the stairwell

View to the right shows elevator shaft - this must be where the blocks were falling from?
[img

I finally found a good pic of the deck below the stairwell door to the pool deck, I hadn't realized the deck had collapsed under the planter, you can see right into the basement...and the planter is still hanging to the wall!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Also, did we ever decide what these items on the roof were, this is a satellite photo est date 6/22/21, showing the roofing crane as roof work was still in progress.

What is that large round silver object?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Optical98 (Computer)2 Sep 21 03:03)

you can see right into the basement...and the planter is still hanging to the wall!
Here is where I could just use some them thar power-pointy arrows to see what you're talking about

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

SF Charlie

Let me know if this helps, I have Power-point and have viewed pics on it, but have not Used PP for a long time..

The green lines are the planter and the red arrow points to the basement.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yes. That is a planter and that is a stub of the deck still attached to the wall. The edge below your green mark is part of the collapse edge of the pool deck with a view into the carpark beneath. That collection of stuff shows up in a number of views of the rubble pile taken early on in the recovery.

AusG

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I was agreeing with you out loud. There had been some debate a few threads back about that door and planter being what it is, so I added my vote.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

AugG

Thank you. I've gotten too used to snarky replies on here, lol.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Optical98 (Computer)2 Sep 21 03:35)

Let me know if this helps,
Yes, That helps a lot!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

No probs. For my sins I help mod a news & politics website. I see way too much pointless snark to wish to add to it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I have purchased the entire historical series of ACI 318 building codes to understand what were the provisions back in 1970s. And there were a lot of things that have stayed pretty much the same since we started understanding structural engineering and mechanics. The only problem is it is in a USB drive that is formatted and I can’t somehow upload and send it over.

But yeah splice requirements, punching capacity, shear capacity of beams, direct design method, column reinforcement and all are the same. The missing things in ACI 318-77 code were integrity reinforcement, different phi factors compared to today’s ACI, factored load combinations specified by ACI and all.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Sgw1009)

Angela and Devon Gonzalez from 904 were interviewed this morning on the Today show (NBC).

Thanks. This resolves one question…we now know the Gonzalezes did not make it out to the hallway. The floor collapsed outside the bedroom door.

So this means we do not know whether or not their apartment door could have been opened.

I will update the timeline to clarify.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Congratulations on the credit you received on the NYT infographic of 9/1/2021!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MaudSTL (Computer)2 Sep 21 16:33 Quote (StructuralMadness) Congratulations on the credit you received on the NYT infographic of 9/1/2021!)

That is an impressive production. Very well presented.
The presentation is so "real" and complete it brings to mind something that has bothered me over the last 20 years or more - it MUST NOT be allowed in a court proceeding. It is too convincing.
All they left out are the concrete eating termites from Mars.
My point being it will be hard for a jury (there will be no engineers on the jury - particularly structurals) to believe they have not witnessed all the defects that that contributed to the collapse and deaths. The video will instantly make them something like someone who knew the defendant well.
Any attorney working against some point is working uphill already.
Hell, I'm convinced. And I have sat in the box beside the Judge and explained many things to Juries.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Great Graphics
Thanks also to:

#### Quote (gonefishing2 (Aerospace)1 Sep 21 22:31)

Nice Model and article from NY Times titled "The Surfside Condo Was Flawed and Failing. Here’s a Look Inside."
Edit: Warning for some, No mention on Top First.......
Here is the shared code for the article above
The Surfside Condo Was Flawed and Failing. Here’s a Look Inside.
I subscribe to the NYTs and they let me share 10 articles a month free.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

> What if, one of the balconies between the red lines below fails and falls, thus collapsing the pool deck

Any 'a thing falls and starts the pool deck collapse' needs to explain why 111 didn't mention it, as it would presumably have fallen right outside their window.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

A really good presentation from the NYT, Charlie.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

OK folks, too many What Ifs, sounds like we are pulling baseless scenarios out of the sky in search of supporting facts, like throwing a hail Mary pass and seeing what sticks against the wall. I prefer to go by spotting evidence first that leads to a legitimate root cause, something other than falling balconies, which we already explained last night the security video from 87 Park next door showed all balconies seemed to be intact when the collapse started. People actually think that navy ship test blast 400 miles away could have collapsed the building.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Vance Wiley)

All they left out are the concrete eating termites from Mars.

I too was surprised they left out the concrete…they could have quoted the demolition folks and mentioned the ratings the concrete should have had by code.

#### Quote (Vance Wiley)

…it will be hard for a jury (there will be no engineers on the jury - particularly structurals) to believe they have not witnessed all the defects that that contributed to the collapse and deaths. The video will instantly make them something like someone who knew the defendant well.

In St. Louis we have a lot of cases and a small, generous population, so residents are called to jury duty many times. I’ve been called four times, and served twice (once as foreman.) Anyhow, based on my jury experience, this infographic is indeed a jury spoiler.

One of the things I liked about it from the witness perspective is that they avoided the controversy over “which part of the deck fell first” by showing the collapsed area collapsing all at once. Despite what some people think, we have no collapse witness statement to support a deck collapse sequence. Each witness describes what they saw right in front of them…cars fallen into the garage as seen from the lobby and porte-cochere, and the pool deck collapsing as seen from 410. Instead of trying to establish a sequence of deck collapse, the infographic did a good job (at least to a lay person) of showing us the weak columns, the long span, and area left overloaded by the elimination of beams.

The infographic also avoids trying to define what the Nirs call the 1st Collapse…which we have struggled over in our discussions. It could have been any number of things, from any direction.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

One thing a few of us noticed from the NIST video released on 8/25, on which I uploaded my frame by frame analysis video with my graphics overlay on the empty collapse site, is if you look at several closeups of the cut columns and beams you will see there appears to be virtually no large rock aggregate in the concrete, it should be 3/4" aggregate unless the code was different here in 1979 cocaine cowboy era. Yet look at those closeups, and it looks like there is virtually no aggregate in the concrete at all. So each picture now opens up more questions about the strength of the concrete when this condo was built.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

As usual with such articles, the "comments" are very interesting. So many comments mention holding the inspectors and permit approvers accountable... "Longford" could you please reply to a few of those -
"That would start with Finding the many boxes of documents the Town of Surfside seems to have Lost".
That is a fact worth noting, eh?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeff, the video footage from 87 park is so bad that with the right squinting of the eyes, you can even make out what looks like a phallus in those dark shadows. Or maybe thats just my eyes.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
On the 1979 plans, on sheet s14 of 14, (page 35 of the .pdf) the column schedule, there is an 8" by 12" column called out under the letter "P", that is shown to be used on floor basement thru 11th.
I'm not very familiar with the plans, but I can't find where this column is used.
Help!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

Re missing aggregate. I believe it is there (paler grains and patches just visible in the NIST broken column pics), breaking along exactly the same surface and hence no stronger than the surrounding concrete. Local limestone, either deteriorated or more likely never much good in the first place.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

How could the load of a slab possibly applying a cantilever moment and load to a concrete column holding up about 800kips cause a building to collapse?
The south side of the building did not collapse as the slab failed in punch shear and damaged a small area of the column.But there was a beam there tie it to another column. The pics show the column with chunks missing.
So a beam attached to M11.1 tore away from the column and left it crippled. Seismic wave propagated to the weaker columns on the upper floors and punch sheared.
The main step beam needs to be examined as this actually held up the building.
If a joint ran through it that would be the smoking gun.
Also a planter box BM A could have smashed into M11.1 and severely damaged it.
Also the video looks like the collapse starts at the top 5 floors and caused the columns to buckle.
I wonder what shape the piles are in.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

...there is an 8" by 12" column called out under the letter "P", that is shown to be used on floor basement thru 11th.
I'm not very familiar with the plans, but I can't find where this column is used.

Scroll up 7 pages to S7 and look at the East side of the East stairwell.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (sfcharlie)

That 8x12 column you are looking for is gridline Column E on the "Basement Level Dimensions drawing", page 33 of 336. On that page look to where the vestibule is in the garage, and out in front of the elevators to the left you'll see the tiny columns with 8" next to them. These also appear on every other floor level page, sometimes with TC next to it, not sure what TC means

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff (Electrical) 3 Sep 21 01:24 Quote (sfcharlie) That 8x12 column you are looking for is gridline Column E on the "Basement Level Dimensions drawing", page 33 of 336. On that page look to where the vestibule is in the garage, and out in front of the elevators to the left you'll see the tiny columns with 8" next to them. These also appear on every other floor level page, sometimes with TC next to it, not sure what TC means)

Do you have pics of the main step beam and columns L,M,N?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote:

Jeff Ostroff 3 Sep 21 01:24
...not sure what TC means.

TC Could mean Trash Chute.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Those 8x12 in the middle of the lobby would not be trash chute, they are too small. The trash chutes are inline over the dumpster room

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (CheifInspector)

The only photos I have of L, M, N are in our friend Fiorella's garage video walkthrough of the Champlain Towers South last summer. In there we see the Beam between L and M, which I pointed out in our video seemed bowed.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

Those 8x12 in the middle of the lobby would not be trash chute, they are too small. The trash chutes are inline over the dumpster room

Those things marked TC are right next to a 30 inch diameter hole that ends at the trash room on the first floor. It looks like they are in the corners of a room that you enter to toss your trash so the trash chute opening is not right in the main corridor.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeff without these post failure pics this case can't be solved.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

You might be right then, I got a better view of it of Morabito's plans for the 40 year certification, here is the screenshot I grabbed, and it looks like TC is indeed the trash chute. On the architect plans from 1979 that I looked at it was not drawn as clear as this drawing is.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

What are we looking for Charlie? A column by the elevators or over to the east side? Is it a smaller column, I might have a pic of it?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

You might be right then,

Thank you.

Page 219 of 336 screenshots of trash chute and the "P" columns Charlie asked for:

Edit to add: TC is not an abbreviation for trash chute because I see TC used in other locations on these prints. I don't know what it means.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (nukeman)

Just be careful with this, because page 219 is the Champlain Towers North floorplan. Likely the same, but would have to spend more time looking between that and a real Champlain Towers South pages like 9/336 or page 10/336 or page 20/336, but none of those pages shows the 8x12 columns like the eengineer's drawing that I pasted above.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

Just be careful with this, because page 219 is the Champlain Towers North floorplan.

You are correct. Try page 29 of 336.

Edit to add: TC stands for tie column. Page 38 note 9.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

TC stands for total collapse.

Lock it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Nukeman948 (Electrical)3 Sep 21 01:16)

Scroll up 7 pages to S7 and look at the East side of the East stairwell.

#### Quote (Jeff Ostroff (Electrical)3 Sep 21 01:24)

That 8x12 column you are looking for is gridline Column E on the "Basement Level Dimensions drawing", page 33 of 336.

#### Quote (Nukeman948 (Electrical)3 Sep 21 02:39)

Page 219 of 336 screenshots of trash chute and the "P" columns Charlie asked for:

#### Quote (Jeff Ostroff (Electrical)3 Sep 21 02:44)

...spend more time looking between that and a real Champlain Towers South pages like 9/336 or page 10/336 or page 20/336, but none of those pages shows the 8x12 columns like the engineer's drawing that I pasted above.
Great post!

#### Quote (Nukeman948 (Electrical)3 Sep 21 02:54)

Quote (Jeff Ostroff)Just be careful with this, because page 219 is the Champlain Towers North floorplan.
You are correct. Try page 29 of 336

Thank you all for the help!

#### Quote (Optical98 (Computer)3 Sep 21 02:32)

What are we looking for Charlie? A column by the elevators or over to the east side? Is it a smaller column, I might have a pic of it?
I didn't know, that's why I asked!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
O S, now I C D gofish.
Between M and N, 2 & 4...

Woo! I'm glad I wasn't a construction supervisor on this job.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
So... On sheet 042 of 336 – "ROOF & PENTHOUSE PLAN @ 1 8th in eq 1 ft – 0 in" of the 1979 plan the 13th floor PH is shown?

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Page 42 of 336 near the elevator actually has it spelled out as Trash Chute, confirming the location of those 8"x12" columns.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

Page 42 of 336 near the elevator actually has it spelled out as Trash Chute, confirming the location of those 8"x12" columns.

Well yes, but actually no.
My first post on this subject had all the correct information Charlie asked for.
Your first post, after mine, was the wrong columns, then you continued to try defending incorrect information and told me to be more careful about where I found my information.
"P" columns are different from "TC" columns in the amount of rebar and concrete strength for each floor.
And here you are still defending the wrong columns.
We done?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Here is a link to an upcoming (9/14/21) Webinar many of you may be interested in, you would need to register for it:

Live Webinar
RAND ENGINEERING

SOUTH FLORIDA CONDO COLLAPSE:
ACTIONS TO BE TAKEN

https://myemail.constantcontact.com/Join-Us-for-Li...

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Article of interest >

A snippet:

"We see a privately owned collapsed building in Florida and a publicly owned collapsed bridge in Minnesota as two distinct problems, but in a fundamental way they are not. In one case individuals sweep pronounced problems under the rug and show a moderate cost savings. In the other case an entire nation falls trillions of dollars off the international pace of infrastructure investment and meanwhile creates a tax incentive so a hedge fund can erect a pencil-shaped skyscraper in Manhattan with a $100 million penthouse and plumbing that leaks because the building sways in the jet stream." The Surfside Condo Collapse: A Brief Forensic Study of Missing the Point Entirely https://thebanter.substack.com/p/the-surfside-cond... ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I read the article Optical98 linked to. Leaving out the over-dramatic quote that doesn't appear to make sense, it does have some good points. However, casting structural engineers as the last of the under-paid thoroughly honest and competent group anywhere (also an over-dramatic line) leaves out that Surfside allowed the SE on the job to also be the building inspector on the job (as I recall). And, at best, he seems to me to have done both jobs poorly. Also. On the failed bridge he mentions: wasn't that a straightforward mistake of fabricating the gusset plates out of thinner than specified steel? Quite the contrast to the condo. spsalso ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 I went down to the Champlain Tower South collapse site today and shot some interesting video of the rapidly changing site that NIST was not showing us on their quick updates. This has to be costing millions, there are cops everywhere preventing you from getting past the property line. I also got some video across the street from the Champlain Towers N building, which is 3 buildings north. I basically duplicated the famous tourist video in the daylight, and got to see a much better brighter view of the columns in the afternoon light, as well as unobstructed views of the columns when a car came out and the gate went up. ### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12 (OP) #### Quote (Jeff Ostroff (Electrical)3 Sep 21 23:11) I went down to the Champlain Tower South collapse site today and shot some interesting video of the rapidly changing site that NIST was not showing us on their quick updates. I'm not kidding. Next time you go, schedule a visit to 87 park to see about an apartment for your daughter who will be attending the most expensive university in Miami. She'll want a unit on the North (shady) side of the building. You have to take some video off the deck to show her.... Then go to the hotel and ask the staff to show you a unit on the south side (overlooking the pool?) shoot some video and tip them well ($1 bills don't cut it anymore)
Looking forward to seeing the results on YouTube!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I can tell you that being an investor and remodeler myself who has bought and sold many condos over the years, every time there is a major event, hurricane, catastrophe, financial meltdown, etc., something big changes in the paperwork that has to be done sometimes even to sell your unit.

For example, in 2012 they passed a law requiring condominium boards to take out fiduciary bonds, which protects us condo unit owners if people from the board of directors take off with the money or siphons away cash.

And in one of my condos where I was trying to sell the unit, the deal fell through, because the lender for the buyer asked for that proof of fiduciary bond and did not get the proof of a fiduciary bond. Then we found out that there was no bond and we were furious that the president of the HOA had not secured any of that insurance. But luckily the buyers brought in a third buyer and paid cash for the unit which ultimately saved the sale for me.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The police presence points to a criminal investigation. I am wondering is a suicide driver was involved. the whole scenario is too weird.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

[quote Jeff Ostroff (Electrical) 4 Sep 21 00:41 I can tell you that being an investor and remodeler
Can you post the pics?
Did you any bomb sniffing dogs?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (ChiefinspectorJ)

I am wondering is a suicide driver was involved. the whole scenario is too weird.

If you go back five or six threads, you can review the discussion about a car hitting a column. When you review the Collapse Witness Timeline, you can see that we know that the following people used the garage immediately prior to the collapse:

<1:15 Nicolas Vazquez and Gimena Accardi (who were in the elevator when the deck collapsed)
~12:50-1:00 Eric Zion
~12:30 Sarah Nir and Gabe Nir

What we do and do not know:
• No one has volunteered any information about seeing or causing damage in the garage at the time they were there. No interviews to date have included questions about the garage.
• No one has volunteered that they heard any knocking sounds (which were heard in 111 from 11:00 PM on) while in the garage. Vazquez does say they heard a couple loud cracking sounds several seconds before they got on the elevator.
• We do not know what parking spaces any of them used. Depending on where they parked, it is possible for damage to have occurred outside of their lines of sight.
• There may also have been other garage users we don’t know about.
Basically, at this point, unless new information is revealed, any speculation about a driver hitting a column is just that…speculation.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yes, the car into the column scenario is another failure mode in search of evidence.
I will tell you today I got video outside Champlain Towers North of the view that tourists video was shot, but mine is in the daylight, the gate was open and we can see all the columns, where they should be, and it will put to rest all arguments people have on the tourist video as to which columns are where and what is missing.

I won't be posting my Champlain Tower pics or video that I shot today until I upload the final produced video onto my YouTube Channel, to prevent other channels from stealing my photos and video and getting a first-mover advantage on it, or run around trying to claim it was their work like we have witnessed lately.

I am also miffed the NYtimes appeared to use a lot of my early work and deductions without giving me credit I know they said: “some engineers said”…. It seems they were doing a research paper based on other's work, they even gave Miami Herald credit for their Aug 8 article but not the rest of us.
As far as I know, my channel was the first to offer a minute-by-minute timeline in video form on my first How IT collapsed video, which got 5 million views and a few press interviews for me, so I know they were watching my content.

Then Maud came along and did that awesome spreadsheet of the timeline which I now use because it has much more granularity and clickable evidence links to back up data points. Very well done Maud. It was obvious they referenced that spreadsheet but I did not see the credit to Maud.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Jeff Ostroff (Electrical)31 Aug 21 00:13)

the tourist video showing approximately where they were seeing all the debris landing on the garage floor.
Jeff, is there an established time for the tourist video? I'm trying to place it in time relative to seeing the (valet parking) cars in the basement.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

I had read an article where the lady who shot the video said it was 1:18 AM when she shot the video based on the time stamp on the video file in her phone. There is also another video she shot which most people don't know exists, it shows her and her husband after the collapse they got into the elevator in her hotel across the street, and you can see their lags were pretty banged up and bleeding from the rubble when the condo collapsed, and small chunks shot all the way over to the hotel pool.

This aligns exactly with 911 calls, from 1:22 AM you can hear the building collapsing in the background.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

BTW folks I don't know if this has been brought up or not, but I confirmed when I was inside at CTN today:

But, the Champlain Towers North and South are NOT carbon copies. Many people think they are the same because many framing plans are the same. But Champlain South has 12 units per floor, and Champlain North has only 10 units per floor. The floorplans of the units are different, even though the pool deck, and balconies, and look of the buildings are pretty close. I got photos of the drive-up porte-cochere and the above-ground parking deck, and the pool gate from the parking deck. The pool is now closed indefinitely as they do their 40-year inspection.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

… is there an established time for the tourist video?

ABC News quotes the 1:18 AM timeline. This is in the Data tab in the Timeline spreadsheet.

Edit: This one is actually better. NBC News states the Before video was time stamped 1:18 AM, and the After video was time stamped 1:27 AM. I just added this to the Notes in the timeline.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Jeff Ostroff (Electrical)4 Sep 21 03:18)

As far as I know, my channel was the first to offer a minute-by-minute timeline in video form
Thanks for calling my attention to this image:

Max building fail in Miami
This is consistent with what I saw in my frame by frame analysis. I find it difficult to explain the strange angular brake to the east of the stairwell shear wall, but it appears to be what happened.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The reason I support the car collision premise, is that there is a missing column. It did not punching shear. It was missing prior to collapse.

Its really simple, car hits column, its attached at the top by a beam from the direction of impact. It has every reason in the world to bottom shear. 40km/h is enough to take out pool deck column 12x8 inch.

Were any bodies recovered from inside cars?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I feel like we're going round page 7 again here but ... People heard noises that indicate something was happening well before the final collapse. At least three people were in the garage after those noises were going on, and none of them reported a crashed car. And if we're talking about M11.1 as the 'missing column', well, that's immediately at the bottom of the parking ramp, there's no way people entering the garage wouldn't have noticed a crashed car and broken column there.

As far as I know the only 'evidence' for this column being 'missing' is the TikTok video? If you look at that video, you also can't see M12.1 - but we know that column did in fact stand up and the slab fell around it, hiding it from the camera. I don't believe you can be sure that the same isn't true of M11.1. In the cleanup videos you can see that the bottom rebar for M11.1 is there after column and debris removal, and doesn't look any different from that of the other columns nearby.

> @Jeff - Champlain Towers North and South are NOT carbon copies

In particular according to some people in previous threads, the slab step at the building side of the pool deck isn't there. I'm not sure the M9.1-M11-1 beam is either. But the column layout is the same so it should be good for the parking ramp video if you've lined it up correctly.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

I will tell you today I got video outside Champlain Towers North of the view that tourists video was shot, but mine is in the daylight, the gate was open and we can see all the columns, where they should be, and it will put to rest all arguments people have on the tourist video as to which columns are where and what is missing.

Well you can't put to rest all arguments until you after have heard all arguments,(and you know I have one).
So far nobody has said much about the fact that the collapse shown in the tic-tok video has taken out the lights beyond the ramp. I have been in parking garages with rows of lights off and it is freaky how things like columns just disappear when there are no lights shining on them.
Is there any chance you could get some video of a garage or other room with rows of columns and show the effect of turning off lights towards the back of the room?
My point is that I believe all the columns are there but we can't see them with the lighting that is available. This also makes it impossible to see how much damage they may or may not have.

#### Quote (Red Corona 4 Sep 21 10:20)

Your post got a star from me. Excellent logic.

#### Quote (AutisticBez)

Were any bodies recovered from inside cars?
40km/h is enough to take out pool deck column 12x8 inch.

All bodies or remains have been recovered and identified.
I have read reports stating that all victims were located where they were expected to be.
No extra bodies or remains have been found.

The smallest column listed for the basement level is 12x16, not 12x8. I even tried to scale off the prints to confirm this.
Perhaps this mystery car had a flux capacitor installed.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The “missing column” theory is a bit wearisome to me as well. And I was disappointed to see it in the NYT piece.

Is the idea is that something hit it with enough force to shear it flush at both the top and bottom and knocked it completely away?

Or did it get laid over at 90° right at the base leaving it even with, and parallel to the ground? Shearing all of that rebar cleanly at the ceiling.

Those columns have proven to be like box of spaghetti noodles as far as the rebar goes, but all of that has disappeared too.

If the column has been hit (or otherwise damaged) I would have expected to see a buckled or stoved mess where it was. Not nothingness.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Spartan5)

If the column has been hit (or otherwise damaged) I would have expected to see a buckled or stoved mess where it was.

Exactly right.
It must be there, either still standing, leaning, or in the debris pile, but I suspect we just can't see it because of the lighting. And no video from CTN taken in the daytime with all the garage lights on will convince me otherwise.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Jeff Ostroff)

Very well done Maud.

Thank you, Jeff! I am a big fan of your overlays, because they reduce confusion and help develop a common understanding of what is where.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Well why is the place a crime scenes? Politics? Something is going on.
The only structural scenario I see now is the beams holding up the planters torn chunks of concrete from the main step beam which held up the building.
I have not found any sections showing how the BM A's were tied into the step beam.
One plan shows a 2-6" beam and another a 1-6" beam. Also there was a large load on that beam from a weight room.
The BM A's also tied directly in to the columns K, L M and probably damaged them similar to the damage on the other South east punch shear beams.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (ChiefInspectorJ (Specifier/Regulator)4 Sep 21 23:06)

Well why is the place a crime scenes? Politics? Something is going on.
Politics the "Developers" hate the "Surfside" for limiting what can be built.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

3

#### Quote (ChiefinspectorJ)

Well why is the place a crime scenes?

Miami-Dade’s economy depends in great part on real estate. They need to preserve the belief that local properties are safe to buy, sell, and live in. To keep their real estate market viable, they are highly motivated to assure that the collapse of the CTS is blamed on anything other than environment, location, and building age. After all, there are many other buildings just like CTS all over Miami-Dade, and residents are rightly concerned that their building has the potential to be another CTS.

IMO, the County hopes to build a case for criminal negligence by the Town of Surfside and/or the CTS Condo Board. The fact that the Town of Surfside immediately engaged a very highly regarded forensic engineer put Miami-Dade at a disadvantage, because Kilsheimer will focus on a thorough, correct analysis whether the County likes it or not. So they want to keep Kilsheimer out of there so they can buy time to try to build a criminal negligence case that will take the focus away from the realities of aging concrete and steel structures in a highly corrosive environment on a barrier island threatened with imminent sea level rise.

That’s the way I have been looking at it, but I am not local.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

How could the town be criminally liable for this?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

"...highly motivated to assure that the collapse of the CTS is blamed on anything other than environment, location, and building age. After all, there are many other buildings just like CTS all over Miami-Dade, and residents are rightly concerned that their building has the potential to be another CTS."

While presumably trying VERY hard to stay away from the concept of Shoddy Construction (see: "...many other buildings just like CTS..."

spsalso

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

If they have broken the law, and through their negligence deaths were cause... This still hasn't played out in the courts... we don't even have an 'official' report...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

"How could the town be criminally liable for this?"

Negligent manslaughter (Florida): the killing of another person through gross negligence.

The condo board is a tough sell. They're just a bunch of clueless non-professionals. But the city: a person paid to act in a professional manner who......

And if that person could be shown to have been acting in a manner accepted by the city,......

spsalso

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Again… how was the town negligent Hypothetically even?

#### Quote (spsalso)

But the city: a person paid to act in a professional manner who......
The city? Or the licensed professional structural engineering firm that was paid \$500,000 to assess the condition of the building, analyze the as-built conditions, identify structural deficiencies, and design repairs?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

OK, I just uploaded my video to You Tube minutes ago, but here is a screenshot I made from my video, showing something interesting, that will open up more questions.

I noticed while filming the Champlain Towers South debris site yesterday that all the column rebars were pretty much intact coming out of the garage floor, mostly the rebar is vertical. But look at this photo where I pointed to column M11.1, the column most of us think brought the building down when the pool deck collapsed against this column. This is the column underneath that planter, 20 feet outside the building wall. Look how bent and twisted Column M11.1 is, and all the damage on it, hardly anything left. Everything always seems to point to this column.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

If they knowing issued a permit for work that was non-compliant or unsafe, for a start and there are likely several other issues... did they receive any financial benefit from the 'sloppy' work... best let the lawyers sort it out; the possibilities make my head hurt.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

There was a screenshot posted earlier from after the clearance that shows M11.1's bottom rebar looking similar to all the others. If I get bored enough I'll scroll back through the threads to find it.

I suspect that since then they've cut the rebar to take it away for analysis because they think there's something about that column too. Which most of us here agree with, I think, but it's not as simple as that pic makes out.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Column M11.1 is connected underground to that leaning Millennium Tower building in San Fransisco. The more they tug and pull on M11.1, the more the Millennium Tower building leans.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeff Ostroff...better images of the column in question. The way it's curved, looks like something ran into it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Jeff Ostroff (Electrical)5 Sep 21 13:24)

Column M11.1 is connected underground to that leaning Millennium Tower building in San Fransisco(sp). The more they tug and pull on M11.1, the more the Millennium Tower building leans.
First Jeff, I'm looking forward to watching your video.
I wish that M11.1 rebar was the cause of the millennium tower sinking, but alas, they cut the rebar and the tower is still going down, down under the 22 inch limit they set...
We have photos of the basement when it was first emptied, before the excavator tore out the columns. let see what M11.1 looked like then. Thanks!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

In case it's not obvious. Sarcasm.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

2

#### Quote (JDATL)

The way it's curved, looks like something ran into it.

I tend to think that more closely resembles a column that buckled and subsequently had 12 stories worth of building materials crash down on it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
How the tower fell (not why!)
This is the first image from the surveillance CCTV...

Now the camera is warmed up...

Central section falling, East section, not so much.

Central section still falling, East section, still not so much.

First clear evidence of east section floors tipping next to center section.

First clear evidence of floors tipping east of column (j13?)(sheet P4 of 11) 1979 plans pdf 10 of 336.
N10 (sheet S9 of 14) 1979 plans pdf 27 of 336.

column (N10) continues falling, roof line appears intact?

edit: Sorry, I forgot to attach the power-pointy file: (It' set up as a slide show...)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (arbitraria (Civil/Environmental)5 Sep 21 16:19 Quote (JDATL) The way it's curved, looks like something ran into it.)

Perhaps an M1A1 Battle Wagon (Abrahms tank).
We can more accurately surmise that the rebar is not GREATLY corroded - it took some severe bending without snapping. Thus shifting focus to concrete quality at the time.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Look at the red arrows on my OP. You are looking at the wrong rebar.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

2
EDIT: disregard I did this wrong. Leaving here so the following posts make sense

Re 'missing' column - @Spartan5 pulled this screencap from a site video in part 8. You can clearly see M11.1's bottom rebar sticking up like all the other columns, so it certainly wasn't 'missing' up to a height of about 3'.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Is M11.1 the missing column?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Red Corona)

You can clearly see M11.1's bottom rebar sticking up like all the other columns

The rebar sticking up in the right hand square is from column 27, otherwise known as column M10. The pile was pushed from M11.1 toward the drive ramp before this photo was taken.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Wait up, the column in your picture is M10 not M11.1 and M11.1 is clearly missing. M10 is 1 spot away from ramp. The 10 columns are at the edge of building. M11.1 is the thin column under pool deck connected via beam. Your photo of the basement is M10.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Rofl, someone can't count. 9 (skip a column) 11.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

JDATL.

You evidently missed my point. I know what rebar you are pointing at. I'm merely pointing out there is a ton of other rebar equally (if not more so) damaged, and therefore how contrived the vehicle impact argument is by just picking out the bent rebar which supports that 'theory' whilst ignoring all the other equally damaged rebar all around the site.

Did something drive into all the other rebar which bent those too!?

Can we please just put the whole vehicle theory to bed. This building wasn't brought down by a car.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

It still appears that there is a bundle of rebar there at M11.1 in the rubble pile laying over to the South-East but it's hard to tell from that picture if it was mangled by that excavator, the falling building, or an Abrahms M1 tank.
Of course velocity has a large effect on impact damage. Perhaps a vehicle traveling at 88 MPH with a net force of 1.21 jigggawhats of energy. That just might be enough to vaporize that tiny column and it would explain without a doubt why no car was found against the column.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Three ways a column can fail. Punching shear, most of pool deck, buckling, under building. And lastly, bottom shear from vehicle impact :)

M11.1 is a bottom shear. Find me a single photo of its intact rebar at the bottom.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

40km/h is fast enough to bottom shear a 12 by 16 column. Fact. I even posted the research data on this.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Lol ok that's what I get for doing that in a rush. Yeah you're right this pic isn't the one I was looking for, 11.1 line is still buried under the debris here.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

My two photos with the red arrows are pointing to 11.1, guys. The single piece of rebar sticking up.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Can we please just put the whole vehicle theory to bed. This building wasn't brought down by a car.

New theory: crane operator put a car full of tar paper on the roof (because it was easier to lift the whole car instead of unloading it first). In doing so they damaged the parapet wall ever so slightly. They had planned on loading old AC units onto the car to be lowered down with the crane at a later date.

While driving the car around on the roof the night of the collapse, one of the engine rods started to fail (loud knocking noises). But these laborers, being the really bad coked up Floridian type, kept driving it anyway.

The car then threw the engine rod through the block. It spun out on the oil slick, and crashed through the previously damaged parapet wall.

These guys, not being total f-ups, had considered this could happen and had tied the car off with an extension cord to a roof anchor. The roof anchor, having been poorly installed because they were drunk, failed to arrest the fall of the car. This was all signed off on at the highest level of town officials.

The car, laden with ac units and tarpaper tolls, plummeted to the ground trailing a long length of cord and a roof anchor (maybe more than one, we can’t be sure about that).

It smashed through the patio after glancing off of a planter which redirected it at a 45° angle right into the base of M11.1, totally obliterating it, and leaving behind the telltale u-shaped hook in the regard one would expect of the bumper of a Volvo station wagon.

It’s all there in the pile that has a few cones around it. PowerPoint to follow.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I think the photos above with the green square around "column M11.1 are wrong, I think that is M10, and M11.1 was damaged so badly there is none left of it to show in the rubble pile. I need a link to the video directly so I can see larger but M11.1 should be in line with those 2 excavator shovels and looks like you can see a stub of it on the garage floor in line with them.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

OK, I found the video, and took this screenshot from a better angle, and I added my labels showing you where M11.1 should be, it is still under the shallow end of the dirt pile, which means there is not much left of that column, just like I showed in my video that I shot at the site on Friday. Hope this helps!

.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

There were several columns that were cut way down or only had 1-3 strands of rebar showing after they cleared the basin. TBF, that particular one is in what seems to be ground zero tho.

I think the ones sprayed with red are the columns used for demo.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (JDATL)

Yes your red arrows correctly pointed to that M11.1 column that has nothing but one or 2 rebars coming up out of the ground.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Egads...can some of you old timers speak to the site/platform owners about the low graphics?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I know the resolution stinks, and I upload high res photos, but it compresses it down. You should be able to click on the photos and have it enlarge.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (JDATL (Industrial)

Apologies - My comment was directed to the bundle of #11s bent over to the left.
The single bar at the first photo looks like a single #4 - maybe a #5. I cannot tell if there were more bars. That is far less than a structural column would have used.
In the second pic the worker is holding a bent bar of similar size. Not sure why that piece is of interest.
If that is a piece of a wall or jamb or infill cmu then I can see a vehicle impact causing damage.
But if that were a structural column it should not have been important to the stability of a 12 story concrete structure and loss of that less than significant capacity should not have caused a collapse.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Where does the "vehicle impact" fit on "Maud's timeline Of Doom".
The building was making failing noises for two hours before the collapse.
Did the "vehicle" hit two hours earlier and nobody saw it? Nobody reported it.
No vehicle was ever found crashed into a column.
Can you obliterate a column and still drive away?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Vehicle damages M11.1, leading to progressive failure of pool deck, then compromising building columns connected via beams. Find me M11.1 intact.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AutisticBez)

Find me M11.1 intact.
40km/h is fast enough to bottom shear a 12 by 16 column. Fact. I even posted the research data on this.

Find me the damaged "vehicle".

I found your research. Your "facts" leave a lot to be desired.
It used computer simulations for the column and car and said: "A shear fracture occurs at the joint when the speed exceeds 40 km/h for columns with dimensions 400 mm or less"
Shear fracture does not equal displacement.
A different study I found said: "The occurrence of plastic
deformation in the car determines the importance of using of a real car in the
experiments instead of a rigid projectile. For crash tests at high velocities large
plastic deformations in the car are predictable but this is not so obvious for low
velocity impacts".

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Also if a car hits a column, the weakest point for shearing is likely at the 5 to 6 foot height, not at the height a car would hit it at, the closer to the ground you are, I would think you have more strength to the column from lap joints of rebar coming up from the layers below, like the foundation.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

AutsticBez

That column wasn't numbered was it, it was between parking spaces?
Is it behind these?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Optical98 (Computer))

If I am not turned around, the column would be one bay (+?-) west and one bay north of the corner of the pool - right? The column in your pic just posted with number 40 (or is that 43) painted on its surface?
EDIT - Nope - Sheet S2 shows it as the next column north of one marked 40/43?. I cannot read the number painted there - maybe 38?
EDIT 2 - the pool plaza columns are designated "N" and 12" X 16" with 4 -#7 rebars. One must interpret the note for concrete strength - it could be 3000 psi.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Vance Wiley

42 and 40, 28 is behind 40
I can't see a number on the column behind 42

Yeah, I think we're looking for the column behind 28, and it's under the rubble.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Yes in photo find column #40, then look to left is #28 right over the firemen's white helmets, then M11.1 should be to the left of that, but it is under the rubble pile.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
So it's taken us 29 minutes to realize M11.1 was under the rubble when everything fell toward it during the collapse. What I want to know is how did the slab drop beam fail at M and K, so the whole center façade could fall as one?

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

What we do know is that all of the surrounding columns to M11 are standing straight up and were not pulled in any direction.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

So what if this collapse has nothing to do with Column failure, what direction would you go then? Slab failure?
There were indications that the generator room floor was weak, they intended to reinforce it for new equipment..

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Optical98)

What we do know is that all of the surrounding columns to M11 are standing straight up and were not pulled in any direction.

Scroll up to the last picture Jeff posted and put an eyeball on M9.1. Does that look plumb to you?

The generator is on the opposite side of the building from where the collapse started and was strong enough for the old equipment that was still in place. There is no evidence of a "vehicle" hitting the generator.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I didn't say anything about a vehicle.. And you should watch some of the videos showing heavy equipment rolling over and grinding into the basin floor right in that area by the pool. They used that area heavily to bring equipment in and bring debris out. So it is no wonder many of the column stumps are bent and ground down.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Optical98)

And you should watch some of the videos showing heavy equipment rolling over and grinding into the basin floor right in that area by the pool. They used that area heavily to bring equipment in and bring debris out. So it is no wonder many of the column stumps are bent and ground down.

And this is precisely why nobody should be using the condition of the column stumps or any other objects in these pictures to support any hair-brained theories.

Sorry about the vehicle jab, it was just the main hair-brained theory of the day.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Nukeman

Any investigation will be looking at objects in the pictures.
I try to stay open minded when presented with theories or maybe not even theories but a desire to talk thru an idea objectively. And I always appreciate the same courtesy.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Spartan5 )

Interesting theory. Where are these items in the pile?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Optical98)

Any investigation will be looking at objects in the pictures.

The investigators were there for the entire process and documented every piece of evidence as it was uncovered. That is far different from a snapshot in time with almost no context. Like taking video through the fence weeks after the site is cleared.

I keep an open mind too but there are limits when the flaws in the theories are so obvious.
You want to discuss how it started with the generator? Go for it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeff Ostroff

I highly suspect there are only about 6 people posting on this entire forum, each with as many multi-personality sock accounts they use to derail any serious concepts or convos.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Vehicle collisions with columns cause a bottom shear. The damage doesnt occur at impact. The bottom is the weakest point.

M11.1 did not puncture shear, so where is it? A car didn't do it, then how the hell did it collapse? Was it the one pool deck column that managed to survive a similar fate?

Its ground zero, what happened to M11.1. Find me this column intact.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Looking at it another way: RC structures have been built since early 1900s and RC is the most common structural material in a world 60% urbanised. There are 5 billion adults in the world, (so 2.5 billion stupider than the median) driving 1.4 billion automobiles, many in places with imperfect building standards. If car/column interactions brought down mediocre buildings we would not be guessing about it here. Sure, maybe that one time in a billion that the conditions are just right, the relative zephyr/love tap of a car on a column might precipitate a chain of events like this, but even if so the question for builders and designers would be those preconditions, the design and the construction, because cars and idiots fall within the design brief.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AutisticBez)

What evidence shows M11.1 did not puncture shear? It could have been the first one to puncture shear but we can't know for sure because it got buried under 13 stories of rubble. If the damage didn't happen at impact, did it happen a week later? Maybe before the impact?

(please excuse me while I switch accounts, and personalities because... uh... reasons)

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Question:

#### Quote (AutisticBez)

What happened to M11.1?

Its ground zero.

^ Ahemm....

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

I just found evidence of multiple additional car strikes. Thoughts?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

So it's like Murder on the Orient Express? Everyone was in on it? every owner drove a car in a pillar? That pillar in the photo above is on the northernmost edge of the property and is bent like that because the whole building came down on it, causing it to bend.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

So it's like Murder on the Orient Express?

That’s been the approach to this here for the last ten threads or so. It’s all most have at this point. Barring any other videos or photographs from that night, it’s all that there’ll be for some time.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (ChiefInspectorJ)

Interesting theory. Where are these items in the pile?

You will have to credit others for identifying the items. I can only claim the creative writing behind the theory.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Just to go back to the real world for a sec. Isn't that column pic the visual evidence right there of columns being undersized for the amount of steel?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeff, its more plausible then a video of you pointing at expansion joints and minor spalling occurring at the bottom corner of that joint, and making out that the entire building is going to collapse based on a little water seeping through an expansion joint.

Cars hit stuff, I know one person who wrote a car off on a column. So it does happen. 40km/h is a slow speed, and between the column and the entry is like 100 foot downward slope, my car could do that just rolling naturally without any gas.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AutisticBez)

40km/h is a slow speed, and between the column and the entry is like 100 foot downward slope, my car could do that just rolling naturally without any gas.

LOL, You're not even close to reality. Let's find some real numbers and see what it works out to.

From the prints we have a grade level of 10 feet 10 inches. The garage floor is 2 feet 2 inches which gives a drop of 8 feet 8 inches.
The ramp length from the property line to the bottom at column line 8 is only 83 feet 4 inches.

Well I'm not smart enough to figure out rolling and wind resistance for your Australian hooptie and how to apply all that to acceleration on a ramp, so I skipped that nonsense and found a free fall calculator online and the numbers only come out to 26km/h. Surely the acceleration on a ramp will give a much slower speed than free fall.
Feel free to check my math.
And please share with us your evidence of a real car and how you determined it was going precisely 40km/h.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Can anyone find pics of the main step beams? The one at the building line is 12" x 19" which also is holding up the weight room. The step beam behind the planter has 2 drops in it with BM A's under it somehow attached to the step beam.
Also if someone can do calcs on this beam with a cantilever moment of the deck and planters added to the other loads?
The columns appeared to be the strongest element in the building.
They are a red herring and performed way beyond capacity..

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Once again there's no way a car could have run into M11.1, which is right at the bottom of the parking ramp, at any time before 01.15 (well after serious problems had already started as reported by the Nirs in 111), because people coming into the garage would have seen it. That's even if you think a car hitting a column could theoretically fracture it and damage it structurally.

> M11.1 did not puncture shear

What's your evidence for that? M11.1 was buried under the debris of the initial collapse, and then also by the eastern section, and during the clearance heavy equipment was dragged all over it.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Spartan5 (Civil/Environmental)6 Sep 21 04:15)

You will have to credit others for identifying the items. I can only claim the creative writing behind the theory.
At least, some of the item identifications have been debunked in the thread they were posted in, and their poster, in that case, acknowledged the incorrect ID and asked for other suggestions!

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

An Ancient Girl Had Parents From Different Species. Scientists Are
Dumbfounded

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharile)

At least, some of the item identifications have been debunked in the thread they were posted in, and their poster, in that case, acknowledged the incorrect ID and asked for other suggestions!
The poster said (to paraphrase) “yeah I guess that AC unit is only as big as a construction cone as you have pointed out.” They left the rest of their theory that follows ‘hanging’ so to speak. Mine is at least as plausible as theirs.

In any case, I will agree with you that maybe those aren’t AC units in that picture. What else do you think it is they could have loaded on the car before it lost control and drove off the roof?

#### Quote (MarkBoB2)

I believe this object is the condenser of an air conditioning unit. Near this object lies a square piece of sheet metal with rounded corners that has a circular hole inside. I believe that this the metal top of the air conditioning unit. One would expect the cable to go through this circular hole as well. But one can see a slot in one side of the top that has allowed the cable and top to be separated. This slot could have been made by the recovery crew to allow easier inspection of the top, or could have been made by pulling on the cable by a power shovel while the top was still covered by the debris pile.

Now, I would wager that it is no accident that this cable extends into the internal condenser part of an air conditioning unit. Normally, the top of an air conditioning unit is covered by a wire grating that would prevent a cable from randomly penetrating inside. However, if one wanted to raise or lower an air conditioning unit with a cable, instead of putting it on a platform or using a lifting sling in some manner, it is easier to just remove the circular grating in the metal top and pass the cable hook through the top opening, then around a compressor support bracket at the bottom of the condenser, and then reattach the hook to the cable again. This alone would indicate that a human being was responsible for attaching the air conditioning unit to the cable.

So, why is the object of interest (whether an AC or some other object) still intact and still attached to the cable after the building has collapsed? Clearly, something went wrong during the raising or lowering of the object that prevented the person involved from detaching the cable. This something that went wrong could not have happened near the top of the building, because then nearly all of the cable would still be in the winch and not strewn all over the debris pile with the object still attached. Therefore, it must have happened near the pool deck. But if the winch malfunctioned in some way to cause the object to fall freely to the pool deck with the cable still attached, then the object likely would have been dented beyond all recognition by the collision with the deck floor. Clearly, the TikTok video shows that this object is still relatively intact. But what if the something that went wrong occurred just a few feet above the pool deck? This could happen if the cable was not long enough. In this case, the users involved might be tempted to gain a few more feet to safely put the object on the deck by tilting the crane at the top a little bit. But when this was done, the change in the crane’s center of gravity could have caused the crane to press against the parapet, causing a moment arm of over 7 feet (4 feet of parapet height plus 3 feet of clearance) with over 300 pounds of force to be applied. This may have caused part of the parapet to give way, sending it crashing down onto the most sensitive part of the building’s structure; namely, the beam between column 27 (column M10) and column M11.1. In this case, the object of interest would fall only the distance of one floor plus a few more feet, which would enable it to stay relatively intact. It would also have resulted in the object of interest falling midway between the hoist counterweights on the debris pile as observed in other photos because the object would have been pulling down on the hoist structure, thereby keeping it centered on the object.

1) It is likely that there was a second person at the bottom of the building as well as one at the top. This is likely because someone is required at the bottom to remove the hoist hook from the object and cart it away, while someone at the top controls the hoist. This second person was likely in cell phone communication with the one at the top. This would have allowed almost silent operation under normal circumstances after 12:00 AM at night. But this second person might have been seen by a surveillance camera having a line of sight over the patio area of the pool deck. This person at the bottom would have been exposed to the falling parapet and may have been injured or even worse. Nothing has been mentioned by the recovery crew about finding a person near the object of interest.

2) The amount of cable required would have been at least 120’ 8” to cover the distance from the penthouse roof floor to the pool deck below. An additional 8 feet or more would have been required to get over the penthouse parapet (4 feet tall), the height of the air conditioner (3 to 4 feet), and either a cable pulley or a winch (1 foot), thus adding an additional 8 to 9 feet. Therefore, the total cable length required would have been 129 to 130 feet. Most commercial winches have only 120 feet of cable, some have 130 feet, but very few have over 130 feet. Therefore, the amount of cable needed was right at the limits of most available winches.

3) With the pulley or winch needing to be 8 to 9 feet above the penthouse floor, the hoist would have been quite tall. Also, it would have needed to extend at least two to three feet over the parapet to clear a 3 foot square object like an air conditioner, so it would have required a counterbalance over 8 feet long with weights greater than 300lb x 3/8 = 100 lbs to stabilize the hoist in two directions. Two hexagonal weights on rods were found on the debris pile that could serve this purpose. Also, this large hoist would likely have been present when the building inspector was on the roof the day before the collapse, so he should be able to give a description of the hoist.

4) A winch would have been attached to the hoist structure. This winch would have fallen to the pool deck below with the hoist structure, probably causing the winch to be seriously damaged. An object was found on the debris pile that appears to be this winch, with the motor and cable spool separated from the housing. However, no other parts of a hoist structure have been observed except for the two counterbalances and possibly a pulley.

5) Operation of a hoist on a roof requires that the hoist have a tie-down cable to a secure building structure to prevent it from falling. There was no such secure building structure on the penthouse roof near the hoist at the time. Therefore, the workers may have used the aluminum framework of the air conditioner mounts as a tie-down structure. Evidence of an aluminum framework with a second air conditioner attached can be found on the debris pile at the end of the ramp.

6) Could the falling of the penthouse parapet wall above and its crashing to the deck correspond to Maud’s first stage of collapse? The second stage of collapse has been identified as being caused by the falling of the pool deck, which might have taken place after a short pause.

7) Could the “knocking sounds” or “hammering on the roof” heard by a tenant and by the night watchman before the collapse have been caused by compressed air guns being used to remove air conditioners from their mounts prior to moving them?

8) Could the weird smells noticed by some tenants have been caused by the refrigerant being released from the air conditioners that had fallen? This refrigerant is a gas that normally has a faint smell like either ether or chloroform that some people might find to cause a disagreeable odor. Each air conditioner has about two to three pounds of this gas inside that takes about a half hour to release completely. With a total of about sixty or more air conditioners on the roof falling at the same time, this would have caused over 150 pounds of this gas to be released all at one time, which would have been noticeable throughout the collapsed building.

9) There may be a witness who can tell us who was on the roof that night. The security desk employee should have seen anyone who entered the elevator after hours while wearing working clothes. And this same security desk employee may also have seen them exit the elevator to leave the building after the pool deck collapsed, which he/she should also have seen by watching one of the security cameras. Has anyone asked the security employee about these topics?

I will leave it to others to explain who may have been on the roof that night to trigger this sad sequence of events because of potential liability concerns. Suffice it to say that the trigger for the collapse was likely an industrial accident created by carelessness and stupidity, and not merely by structural deficiencies as bad as they were to everyone’s agreement, including my own. Without this trigger, no one knows how long the building could have remained standing with all its deficiencies. The case is equivalent to an old and unhealthy person being run over by an automobile driven by a careless driver. No matter how old or how unhealthy the old person is, the cause of death is still an automobile accident caused by a careless driver. One can introduce new health measures to keep an old person functioning longer, but only by stopping careless driving can one prevent automobile accidents that cause the death of older people.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Do I think that a car might have hit a column? Yes. Do I think that a car came speeding down the ramp and totally demolished a column? No.

We know that some of the columns were (at best) of marginal size as originally designed. In many cases they appear to have had too much/too little rebar. Concrete was of questionable quality. Pavers/planters/water added additional weight, and provided access for seepage of water. Previous repairs are highly questionable.

Now, consider the possibility that one of the tenants is not a great driver, and occasionally 'nudges' the column next to their parking spot as they are parking. Maybe it happens once, maybe it happens a dozen times over the course of a year or two. There's little visible damage to the column, maybe a chip or two on the corner--but is the impact/vibration enough to internally crumble already damaged concrete, and perhaps loosen it from rusty rebar? Could the structure have been so bad that one little bump (or a series of them) have been the straw that broke the camel's back and brought the whole thing down?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

The ramp is part A of the distance between gate and M11.1

M11.1 is two columns distance from bottom of ramp. Its perhaps nearing 153 feet. Suggesting that the car needs to reach 88 miles per hour to damage a column is incredible.

I am not suggesting the car cleanly blew out the column at freeway speeds. I am saying the car hit the column at maybe 40-50km/h. You know, its late at night, a fee drinks were consumed. An older person is a little bit intoxicated. Old people suck at driving. They are coming down the ramp and the foot taps the wrong peddle.

Impact occurs. Its not enough to instantly destroy the column but its sheared at the bottom a few inches. Rebar at the bottom is broken from rust and the impact. The pool deck was already in a bad state. Somewhere else, another column punching shears, then another. Its a slow progression that maybe takes an hour or more. The sound of this slow progress can be heard in 111 its directly above the area.

M11.1 did not punching shear, because it was damaged before the pool deck collapsed. See, most the punching shear columns remained intact due to the protection the holed deck created. The deck collapsing held the columns pushed through it. M11.1 didn't punching shear, its fallen on its side. Why? The beam at the top prevented it from going through? It buckled, collapsed sideways. Its shear occurred at the bottom. Nobody has a photo of its bottom rebar intact.

In fact there is barely anything left. You think maybe the rebar was brittle as hell? Maybe water had been leaking down it and destroyed it?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AutisticBez)

You know, its late at night, a fee drinks were consumed. An older person is a little bit intoxicated. Old people suck at driving. They are coming down the ramp and the foot taps the wrong peddle.

Yikes with the blatant ageism there!

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

OK, guys, forget for a moment about how the objects might have gotten on the debris pile. The photo below shows the objects on the debris pile that happen to be found found at the same location as the objects in the TikTok video. Therefore, at least some of these objects should be the same objects as the ones in the TikTok video.

The large object immediately behind column 27 (column M10) is the object that SFCharlie noted had only a one foot diameter hole and that I conceded was not an air conditioner. Notice that this object has four mounting feet as I have shown in the annotated version of this same photo below. These four mounting feet suggest the object is associated with some kind of high torque application. Now you tell me what this object is and how it got there. I expect whoever took this photo will have the same difficulty of explaining this object.

Notice that behind this object lies a metal framework with a hole in it that is about twice the diameter of the hole in the first object. This would make it a candidate for the air conditioner that has been discussed at length already. Also notice that to the right of this framework lies what I have identified as a hexagonally-shaped weight on a rod. This object is seen in the TikTok video as shown in the photo below. Also seen on the debris pile as well as in the TikTok video is a metal sprinkler pipe and an object I have called a metal rod in cement. The TikTok video even shows shadows of these latter two objects. Now, you tell me how these objects got there.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (MarkBoB2 (Electrical)6 Sep 21 20:25)

as I have shown in the annotated version of this same photo
Thanks for annotating the photo.
Might you attach the power point, please?
My aging eyes can't make out what this blog does to photos.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
I notice it's almost time for a new part. not yet, but soon.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

Thanks for annotating the photo.
Might you attach the power point, please?
My aging eyes can't make out what this blog does to photos.

I’ve enhanced the relevant portions for you:

Part of me feels badly for posting these things given the serious nature of the incident. But the rest of me can’t help but draw attention to some of the craziness that is being taken seriously.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Jeez, that was a hell of a load of laundry... Honestly I have a scratched cornea today, so I can't read the fine print on your pics Markbob :/

Also, if you want clearer pics of the rubble, go to Getty Images and search CTS Collapse pics. Markbob, do that.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Spartan5)

You will have to credit others for identifying the items. I can only claim the creative writing behind the theory.

#### Quote (Spartan5)

The poster said (to paraphrase) “yeah I guess that AC unit is only as big as a construction cone as you have pointed out.” They left the rest of their theory that follows ‘hanging’ so to speak. Mine is at least as plausible as theirs.

#### Quote (Spartan5)

I’ve enhanced the relevant portions for you:

I was silent from August 21 until September 6, when you resurrected your ridicule of me by re-posting my own previous posts above. Why do you insist on abusing people instead of giving your own theories and defending them? Do you enjoy playing god instead of trying to come up with your own valid engineering solutions?

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (MarkBoB2)

Why do you insist on abusing people instead of giving your own theories and defending them? Do you enjoy playing god instead of trying to come up with your own valid engineering solutions?
I apologize if the abuse seems personal but some of this stuff seems pretty bonkers.

I’ve also posted my ideas. Much is awash in this sea of lunacy though. SFCharlie, for instance, missed my posting of the NIST footage which opened, I believe thread 8, because of all of the nonsense about roof anchors and a pallet of 200 tar paper rolls bringing the building down.

Playing god???? In what manner?

Engineering solutions? We haven’t even identified the problem yet.

But I think I found something that matches your sketching. The smoking gun perhaps:

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Spartan

I agree with Markbob, this ridicule of others needs to stop.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Spartan5 (Civil/Environmental)6 Sep 21 21:27)

I’ve enhanced the relevant portions for you:
I see an evil monster stomping (raining ?) on other peoples' parades. well... maybe not evil, just frustrated with all the conjecture. At least MarkBoB2 pointed out what he perceives where, not one of those "do you see what I see?" This way we can look at it to see if it makes sense or not.
Thanks MarkBoB2 and thanks for the attached file.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (AutisticBez)

Suggesting that the car needs to reach 88 miles per hour to damage a column is incredible.

Well, the comment about 88MPH goes along with 1.21 jiggawatts. It was a movie reference that apparently went over your head.

“I guess you guys aren't ready for that yet. But your kids are gonna love it.”

Back To The Real World...
Some of the posters here are so locked in to their ideas that I'm sure they will never believe the NIST reports when they come out. They will end up as our very own Champlain truthers.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (SFCharlie)

I see an evil monster stomping (raining ?) on other peoples' parades.
If this is the parade grounds, then one dog and pony show is as good as the other.

Maybe this isn’t the parade grounds. I’d be glad to exit stage right if there were another thread that was limited to the posting of new information from reputable sources and other actual engineering information in lieu of all the iSpy, fantastical conjecture, and WAGs we have the last ten threads here.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

4
Do most Engineers behave like 10 year old kids or just most of the ones on this tread right now, why push the same theories repeatedly without adding anything new.

My opinion is that the collapse was precipitated by the deterioration of the concrete in the pool deck. Although no test results from cores have been revealed I believe that the concrete was so weakened by the ingress of chlorides from the environment, lack of proper waterproofing and lack of proper maintenance, that :

1) The slab could no longer act in an elastic manner as designed by the ultimate strength method. Concrete finally failed in compression in a sudden manner instead of the steel failing in an elastic manner allowing redistribution of loads before failure.

2) The severe weakening of the concrete and compression failure led to complete loss of shear strength at the columns where the top of the slab was open and confinement in the bottom of the slab giving most of the shear capacity was completely removed.

Even without a sudden major triggering event the added surcharge DL on the deck due to an added layer of tiles and and waterproofing/sand layer along with any ponding due to excessive rain and lack of drainage of the deck and planters probably contributed. The deck so weakened only required some minor trigger to cause the collapse.

I believe that actual concrete tests will show that the insitu concrete in the deck is about two thirds to three quarters of the specified strength. This is also probably the case for the columns just below the pool deck and just above the parking garage floor.

Poor design, faulty construction and quality control, and lack of proper maintenance all contributed with all of these factors directly or indirectly involving the architect engineers and building officials. Just my humble opinion. Now all of the posters have something to criticize from the structural point of view.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (Spartan5 (Civil/Environmental)7 Sep 21 00:27)

If this is the parade grounds, then one dog and pony show is as good as the other.
Agreed
Maybe if I had led with a gentler intro, I would have gotten farther.
I'd be delighted with the posting of new information from reputable sources and other actual engineering information.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (apper.42)

Do most Engineers behave like 10 year old kids or just most of the ones on this tread right now, why push the same theories repeatedly without adding anything new.

My opinion is that the collapse was precipitated by the deterioration of the concrete in the pool deck. Although no test results from cores have been revealed I believe that the concrete was so weakened by the ingress of chlorides from the environment, lack of proper waterproofing and lack of proper maintenance, that :

1) The slab could no longer act in an elastic manner as designed by the ultimate strength method. Concrete finally failed in compression in a sudden manner instead of the steel failing in an elastic manner allowing redistribution of loads before failure.

2) The severe weakening of the concrete and compression failure led to complete loss of shear strength at the columns where the top of the slab was open and confinement in the bottom of the slab giving most of the shear capacity was completely removed.

Even without a sudden major triggering event the added surcharge DL on the deck due to an added layer of tiles and and waterproofing/sand layer along with any ponding due to excessive rain and lack of drainage of the deck and planters probably contributed. The deck so weakened only required some minor trigger to cause the collapse.

I believe that actual concrete tests will show that the insitu concrete in the deck is about two thirds to three quarters of the specified strength. This is also probably the case for the columns just below the pool deck and just above the parking garage floor.

Poor design, faulty construction and quality control, and lack of proper maintenance all contributed with all of these factors directly or indirectly involving the architect engineers and building officials. Just my humble opinion. Now all of the posters have something to criticize from the structural point of view

Myself and others have postulated this same general theory, and have presented it across several posts that can be found in the first few threads of this topic:

-questionable design and execution of a highly-sensitive structural system (two-way flat slab susceptible to a punching shear mechanism that is inherently magnified by moment imbalance)

-an unforgiving environmental exposure that pours water and chlorides into the aforementioned structural system

-suspect quality of construction and construction materials

-non-existent periodic assessment/maintenance
.

This boring, vanilla theorizing has long since been buried by what seems like an incessant stream of rubble pile photo-analysis and other sensational musings, some of which I honestly can't believe are even being entertained as legitimate thoughts.

So a sincere thank you for bringing back this plausible/probable logic, despite the fact that it is clearly not spectacular or sinister enough for an increasing number of posters on here.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

Considering 9/11 20th anniversary upon us,……went down a very deep rabbit hole recently.
It is not my intent to highjack this thread - I just have some items I wish to comment.
If anyone objects, I (or would hope, the powers that be) will take down the post.

The other night I watched CNN Films Present: 9/11, the Peabody Award winning documentary that was to be about a New York City Fire Department probationary firefighter but ended up being a minute-by-minute portrayal of the attacks from the perspective of the first responders who answered the call.
I was very moved. Kept thinking of CTS souls.
The doco triggered me into search.
“Falling Man”, photograph taken by AP Press Photographer Richard Drew. Controversial, and drew much criticism and anger.
“Desperation Forced a Horrific Decision” by Dennis Cauchon and Martha Moore, USA Today, Sept. 2, 2002.
I do not provide links here, because I leave the search decision to readers. Not my intent to be ghoulish. The subject matter is personal.

I kept thinking of New York’s Bravest going UP a 44” stairwell saddled with 50 lbs. of equipment and panicked people going DOWN. And some disabled, and some feeble.

“Federal authorities reported that during the designing of the towers, the Port Authority dropped plans to use an earlier building code that would have required six stairways in each tower, and turned for economic reasons to the more lax requirements of a later code that required only three stairways. By building fewer staircases, it could make more of each floor available for rent.”
-NY Times, Sept. 10, 2004

https://www.govinfo.gov/content/pkg/GOVPUB-C13-8da...

Chapter 10 > 10.2 REQUIREMENTS FOR A FOURTH STAIRWAY (Pages 159 -160)

Sadly, learn from mistakes - fire protection for steel, firefighter-communications systems, sprinkler supplies, elevator use…

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Quote (Seppe)

Myself and others ....

I would encourage others with a different failure mechanism to reiterate their theory here; many have talked about over reinforcement of columns but did it result in failure in a particular way.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)

#### Quote (apper.42 (Structural)7 Sep 21 01:49)

Although no test results from cores have been revealed
1. Yes, except for some PR from NIST, nothing new has been revealed.
2. Core were taken in 2020 and (some) results were presented to the apartment association and can be found in "Minutes of BOARD OF DIRECTORS MEETING held Wednesday, October 14th, 2020 at 7:00 PM".

I understand that more core were drilled and someone (Demented? or YouTuber BuildingIntegrity?) has found photos of them, but I don't know where?

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
Found them:
(hidden on the plan of work performed)

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

(OP)
From the core samples above, YouTuber BuildingIntegrity suggests that a significant extent of the pool deck had delaminated.

SF Charlie
Eng-Tips.com Forum Policies

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

One thing no one has mentioned is that when a contractor last year took those core samples, it appears they cored right through rebar. I always thought this was a no-no. In fact, Surfside sent out guidelines to building owners stating to use GPR (Ground Penetrating Radar) first before taking core samples, to avoid hitting rebar. It is no strange coincidence to me that the core sample which penetrated the rebar was taken just inches to the left of column M11.1, right next to the planter box. You have seen me point out in several of my videos since June about how they left that core site open with Bob's barricade there, and in some other MLS photos, seems like no covering was ever put back on the 3' x 3' exploration site. these core sites are required to be filled back in and returned to the state they were in before the sampling, pretty much the same day if possible.

o Perform GPR (ground penetrating radar) to determine slab thickness and to locate
reinforcing steel, if reinforced (conventional slab on ground or reinforced slab on
ground).
o, Take one set of three concrete cores (after GPR to avoid reinforcing steel) for
compressive strength testing per AC! standards and one core for petrographic
examination per ICRI standards. Repair cored holes in accordance with ICRI industry
standards.
o GPR column for vertical reinforcing steel and lateral ties (measuring spacing) for the full
height of that lift. Verify vertical column reinforcing splices,
o Take one VA" diameter maximum 3"-depth core In column (after GPR to avoid
reinforcing steel) for compressive strength testing per ACI standards and petrographic
examination per ICRI standards. Immediately repair cored holes in accordance with ICRI
industry standards.

### RE: Miami Beach, Champlain Towers South apartment building collapse, Part 12

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!