Miami Beach, Champlain Towers South apartment building collapse, Part 05 111

[SFCharlie]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.
Miami Beach, Champlain Towers South apartment building collapse
Miami Beach, Champlain Towers South apartment building collapse, Part 02
Miami Beach, Champlain Towers South apartment building collapse, Part 03
Miami Beach, Champlain Towers South apartment building collapse, Part 04


SF Charlie
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[Js5180]

Like this, for example:

 

[AutisticBez]

On the left is a completely destroyed column supporting a building. As a result of this impact, the building had to be shored up, and a new column constructed to replace it.

Sohel, K.M.A, Al-Jabri, K & Al Abri, A.H.S, 2020. Behavior and design of reinforced concrete building columns subjected to low-velocity car impact. Structures (Oxford), 26, pp.601–616.

"The columns that are located in car parking garages or adjacent to roadways are highly vulnerable to out-of-plane loads imposed by the moving vehicles. The column that is subjected to impact force imposed by a vehicle traveling at high speed may be damaged severely and lose its design strength, which can lead to failure of the column"

"Consequently, this can cause the column to fail in taking the applied loads on it. Therefore, the loads have then shifted to the adjacent columns, where those columns may not be designed to support such additional loads. In the worst case, the failure of the column can lead to a progressive collapse of the affected building."

Can't even make this stuff up.

"At an impact velocity of 40 km/h, Column C300 suffered moderate damage at the crash point as well as at the base of the column (Fig. 9a). However, at an impact velocity of 50 km/h, the column C300 failed by shear near the base of the column (Fig. 9b)."

"Column C400 failed in shear at a car impact velocity of 80 km/h,"

C300 300 × 300 2.6% 3101.8 27.26 4
C400 400 × 400 2.6% 5558.2 25.99 8
C500 500 × 500 2.6% 8685.8 26.54 12
C600 600 × 600 2.6% 12506.0 27.58 16

How thick was M11.1?

It is possible, you can't rule it out. If the connecting rebar at the top and bottom of the column M11.1 was weak as the rest of the pool deck, well, why not? It's hardly a worse possibility then the roof anchors nonsense that has legitimately no eyewitness statements. If there was a column impact anywhere in the garage, then M11.1 seems like the most likely target.

 

[Sym P. le]

What production model car is ...

My dads Royal Monaco S/W with a 400
... provided the engine mounts are good.

 

[Js5180]

Jbourne,

If the columns are equally spaced on the plans, then the spacing in a perspective photo would be an equal ratio, not an equal spacing.

For example, in the tiktok, if the distance between the right edge of the shear wall, the end of the ramp pillar, and the "27" pillar is the same, then you can take the pixel counts and extrapolate the next pillar location.

Let's say on the plan, the pillars are 20 ft/20 ft/20 ft/20 ft, and in the perspective, the visible ones are 200-160-128 pixels between them. The next pillar will be 102.4 pixels beyond. That same math would put the M11.1 column left of where you're envisioning:

 

[gonefishing2]

Js5180, I sae now, you are saying that object could be CMU in middle of your yellow oval. And yes that could be

 

[gonefishing2]

Ok I see the perspective means the column would have been in front of planter, but planter is still in same area, which is logical. Just on other side of column perhaps. And some of what we are seeing could be parts of failed beam between 27 and 28 or slab.

 

[Js5180]

Thermopile - I'm saying that if you think there's any possibility that the yellow oval is part of a CMU wall, then you have to consider the "fallen roof object" theory, because there are no local sources of cinder blocks at that area. Just like if you see roofing rolls, you are seeing fallen debris from the roof.

 

[gonefishing2]

Js5180, I definitely see what looks like roll roofing and cinder block, now that it was pointed out, and the image was enhanced.

So yes, roof first is still a viable theory

 

[Sym P. le]

Rolls of roofing paper?!?! Srsly, the plot thickens!

CMU's??? Whoa!!!

I have an idea, but I need some time to develop it.

 

[gonefishing2]

As far as the security camera that caught collapse, I am not sure all systems have the look back feature? It was also at night too. My security cameras do have look back feature, and they are triggered by sound as well as movement. So a sound trigger like the penthouse roof falling could have been what 'woke' camera up?

 

[jbourne8]

I drew out the columns too.. perhaps this will illustrate what I was trying to say better. Sort of interesting, but this sort of makes it look like you can only see the bottom of pillar 28, but there's an object in front of it, and the column on top of the planter doesn't seem like it's necessarily part of the same column if that's the case. It's sort of strange too, since there don't seem to be any horizontal columns in that area in the 2020 tour video. Maybe it's part of the pool deck slab?

Anyways, if you take that column and place it on it's side, you can see it lines up pretty well with that white area.

I get those drawings aren't perfect too, but I'm not an artist and they look roughly correct. I think when you look at the negative recoloring of the photo though, that's when it becomes very obvious that there's just one white object on the ground. Not sure what else it could be really if it's not the missing column.

Also, couldn't those bars on the floor just be sprinkler pipes? We know they probably fell down around there too, and there were two of them.

 

[Sym P. le]

If anyone has imagery of the work or documents pointing to activity on this roof portion at the time of collapse please reup it. Thanks.

 

[jbourne8]

Another thing that cinder block shaped object could be are those smaller white planters they had on their pool deck. You can only see them in the most recent photos, but they seem roughly that size. It's hard to say where they were exactly though, since it seems like they moved them around a bit.

 

[jbourne8]

Although.. the part I don't get at all, is if that white object on the ground is the column.. the direction it's pointing doesn't make a lot of sense. I tried to draw it out, but it's like the bottom of it is gone.. and the location of it is too far to the right. It's also not quite angled towards where the column was. I don't get how this wasn't a bomb really.. nothing else seems to fit with how this looks.

Also, it seems like you can see the rebar and metal sticking up in the spot where that column used to be once you draw it out more in 3D.

Maybe these white rocks are bits of the missing column? Again though, it seems crazy how far they are from where the column was.. this is about a car length and a half away.

Sym P. le, you can find them here -

https://surfside.one/public-records-search/

All of the 2021 permits, the 2021 plan, and the preliminary review plans for the 40 year certification are probably worth looking at. The inspector was actually there around 14 hours before it collapsed too -

https://www.palmbeachpost.com/story...cial-roof-14-hours-before-tragedy/5354356001/

 

[zebraso]

Also, it seems like you can see the rebar and metal sticking up in the spot where that column used to be once you draw it out more in 3D.

Speaking of rebar, does this look like a J-hook or where a J hook was in a section of concrete?

 

[Spartan5]

So a sound trigger like the penthouse roof falling could have been what 'woke' camera up?

Remember, it’s been established that the progressive deck collapse preceded the total collapse by at least a few minutes.

Y’all staring way too hard at that grainy image. You might could begin to see Stikini creeping around behind the columns if you squint just right.

 

[Roga50]

New video of the recovery: Link

Behind a paywall but you can watch it in Incognito mode

Several closeups from various angles. Hard to make much out, but there could be clues in there.

 

[AutisticBez]

Okay, so M11.1 is 12 inch by 16 inch by the plans. Guess which side is the 12 inch. The side facing the ramp. So, it's as wide as M10 from the direction of the ramp. But, it's thin. It's 12 inchs. Or 30cm. It would take a car a speed of 50km/h to destroy this column, in ideal conditions, meaning, if the rebar at the top and bottom of the column were decent and not rusted out.

I'm thinking the actual speed of a vehicle required to destroy this column is less then the 50km/h. Depending on the severity of the damage, much less. If the rebar is brittle as hell, as proven by the punching shears, then I don't think it's a stretch to suggest a car had something to do with this.

Now, if this column gets kicked out at the bottom, the car is probably under the rubble down the back.

 

[Murph 9000]

It would take a car a speed of 50km/h to destroy this column, in ideal conditions, meaning, if the rebar at the top and bottom of the column were decent and not rusted out.

A drunk driver managing to do 30 mph into a column at 0100 is certainly a plausible scenario. So is an octogenarian stomping on the wrong pedal.

It might, however, not be necessary to "destroy" the column. All that's really needed is sufficient damage to initiate failure, which could even be delayed. Hit it hard enough to crack it and empty out the rebar cage a little over a few inches, and it will potentially be severely weakened. Or just push it an inch or two out of alignment and the load pushing down is now also pushing it sideways. There are more subtle scenarios than just suddenly destroying it.

I'm not yet seeing actual evidence to conclusively support either of those failure modes, just throwing that out there that it doesn't necessarily have to be a spectacular hit to set things in motion.

Similarly, if a heavy vehicle overloaded the surface parking deck, it could potentially crack it in the afternoon, but maybe the deck doesn't drop until the slab thermally contracts at 0100 (or some other slow failure mode, like each subsequent vehicle causes the crack to enlarge).

 

[Seppe]

Remember, it’s been established that the progressive deck collapse preceded the total collapse by at least a few minutes.

Y’all staring way too hard at that grainy image. You might could begin to see Stikini creeping around behind the columns if you squint just right.

Yep. Some people are so invested in the "roof-triggered event" theory that they are hanging their argument on imagery that is one step above a Rorschach ink blot.