Miami Beach, Champlain Towers South apartment building collapse, Part 10 79

[SFCharlie]

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


SF Charlie
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[dik]

You might consider toning this down... we are getting away from the engineering theme of this website. Speculation should not be included. It's a matter of waiting to see what information comes out from any upcoming reports.

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

-Dik

 

[Demented]

If you're referring to me, sorry for trying to shed some insight into why the site has been being left alone for weeks.

At the hearing before Judge Michael Hanzman, Goldberg called the state of the pool deck an “immediate life safety issue.”

Hanzman was also expected to allow Goldberg to sign off on a roughly $500,000 permit to allow Miami-Dade to hire Bofam Construction Company to brace the retainment walls at the property.

But that permit had a timeline of up to six months, which the county considered “unacceptable,” Hanzman said. The county brought in an additional engineering firm that is revising the drawings and design of the buttressing, and those new plans will be ready next week. Once they are completed, a new emergency hearing will be held so Goldberg can sign off on the permit.

https://therealdeal.com/2021/08/06/...f-collapsing-and-will-be-braced-this-weekend/

 

[gonefishing2]

I find it interesting they are now worried about preserving evidence, and worrying about collapse after tub survived massive heavy metal track- excavator traffic.

Probably 80,000 lb size excavators

 

[Spartan5]

You might consider toning this down... we are getting away from the engineering theme of this website. Speculation should not be included. It's a matter of waiting to see what information comes out from any upcoming reports.

This whole series of threads is further gone than the structural integrity of that patio slab at this point. All of this needs to be reined in. And limited to the dissemination of factual information as it is released by authorities or news organizations (e.g. ENR). Or a discussion of how engineers practicing in the fields related to the design, construction, and maintenance of the building can learn from this failure.

The rest of it should all go elsewhere (Reddit, for instance) with a link to that at the head of the new thread for those who want to partake.

 

[dik]

agree...

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

-Dik

 

[SFCharlie]

What I've learned from my power-pointy do-dad
I've taken a lot of heat for my power-pointy do-dad, but I learned several things from creating it.
1. The wind was so high that the bush in front of the neighboring building was constantly in motion.
2. That, if the leaves on that bush don't move, it is a duplicate frame.
3. That the image in the first visible frame matches the models of the as built building, that Rodface and Santos81 created, with the entire center of pool facing (south) side dropped one story.
4. That the smart posters on this thread didn't need a power-pointy to see that.
5. That there are dark blobs above (behind?) and also to the left (west) of the PH roof parapets, that I can't explain, (of course, that could just be me.)
6. That the entire center of the pool side dropped intact until the 23rd (counting duplicates) frame.
7. That my intuition was correct, you can't analyze time and distance dropped from a fuzzy hand held video of a security system monitor. (due to hand motion, fuzziness, duplicate frames, and more.)


SF Charlie
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[CE3527]

5. That there are dark blobs above (behind?) and also to the left (west) of the PH roof parapets, that I can't explain, (of course, that could just be me.)

I think you are looking at the uncollapsed portions (which eventually collapse) behind the front face that is in the process of collapsing. This may include the lower roof (between the elevator shaft and penthouse) pitching down as well as the 13th floor passageway to the penthouse condos.

 

[SFCharlie]

uncollapsed portions (which eventually collapse) behind the front face that is in the process of collapsing. This may include the lower roof (between the elevator shaft and penthouse) pitching down as well as the 13th floor passageway to the penthouse condos.

Yes That is my suspicion also.


SF Charlie
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[Reverse_Bias]

Is there any sort of a global database on concrete structure collapses?

I know big collapses with lots of casualties usually get investigations, but I'm sure there are a few punching shear parking deck failures every year that only briefly make local headlines. This would probably be helpful in understanding the initial Parking/Pool deck failure.

 

[SFCharlie]

I'm sure there are a few punching shear parking deck failures every year

I googled "punching shear parking", and got plenty of responses, one was on eng-tips.

SF Charlie
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[spsalso]

I wonder how many of them might have been a wee bit short on rebar.
I, of course, wonder the same thing more locally.


spsalso

 

[Demented]

If you feel like paying some $ there's this study. Only an 11 year span though.

https://www.researchgate.net/public...Recent_Building_Failures_in_the_United_States

https://www.govinfo.gov/content/pkg...VPUB-C13-c3d64fd6d7663600a6e3a147919af0a1.pdf

 

[SFCharlie]

BEHIND OUR REPORTING
While federal and local investigations are underway, there is an urgent need for the public to understand what went wrong at Champlain Towers South.

The Herald worked with four engineers and a general contractor who reviewed a trove of records to better understand the circumstances of the collapse. The documentation included structural drawings and design plans of Champlain Towers South provided by the town of Surfside, high-resolution photographs of the collapse debris, and decades’ worth of construction and renovation permits, inspections and other records, including communications from the condo board.

Surfside tower was flawed from day one. Designs violated the code, likely worsened collapse
Link

 

[Santos81]

I have to admit Charlie, that article didn’t disappoint. Every single “expert” contradicts themselves over and over again; something that has been a recurring theme with CTS for a very long time.

The only engineer who has made a completely accurate public statement was Loizeaux regarding the concrete condition of the columns at the basement level.

 

[Optical98]

SF Charlie, can you archive that article and repost it? It's paywalled :/

Oh nvm ^^

 

[Cool_Controls]

So did big Al basically say the North towers looked good before realizing the original construction plans didn`t meet code?

 

[gonefishing2]

@SFCharlie, Thank-You for that article. I agree with Santos81, it did not disappoint and was worth your investment.

There were may great points about inadequate design in this article, and conflicting analysis by experts, but the except below based upon witness testimony and design short falls was very interesting to me concerning lateral movements of building.

"(Unlike frames built with beams and columns, in Champlain Towers the floor slabs provided most of the structure’s lateral stability, engineers who reviewed the plans told the Herald. The only other lateral support in the design was provided by reinforced concrete walls, called “shear walls,” at the stairwells and elevators, they said.
“The shear walls are very small. They are pitiful,” said Santiago, the former building inspector. “They don’t seem to have enough shear walls in one direction.”
When the first floor slab sagged around the columns, the whole structure became unstable and the tower began to sway.
Gabe Nir was in his family’s first-floor condo on the north side of the pool deck when he started hearing banging around 1 a.m., almost like a neighbor was engaged in late-night renovations, he said.
“I started feeling like this whole building started to move left and right,” Nir said. He said it felt like a cheap folding table swaying from side to side.)"

 

[SFCharlie]

Soo... The columns were not wide enough to hold all the rebar nor the building, at least not the pool deck with active load??? and the pool deck wasn't thick enough to prevent punch through???

SF Charlie
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[gonefishing2]

@SFCharlie, reduced column width greatly affected lateral stability in collapsed portion too, especially with lack of sufficient shear walls in E-W plane?

Edit: Miami Herald Article leads me to wonder if first floor building slab starting collapsing before lateral movements took down patio deck?

Or least first floor building slab deflections/failure starting the progressive collapse? If columns were undersized it seems that the extra loading/vibrations on roof would have affected first floor under designed columns and the marriage between the patio deck and the building slab at step down in slab?

Now you have to ask, why did first Builder walk off job?

 

[Reverse_Bias]

There was a long parking garage attached to a high rise condo building collapsed in 2010 in Hackensack, NJ. The building had much better structural support than Champlain tower, and the collapse stopped at the building line. Residents weren't allowed back about 6 months while the structure was being assessed.

https://www.fireengineering.com/firefighting/unified-command-mutual-aid-key-in-garage-collapse/#gref