Miami Beach, Champlain Towers South apartment building collapse, Part 14 41

[SFCharlie]

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

SF Charlie
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[zebraso]

Is it not strange

Strange also might be that there was a floating column and no sign of any splice on the beam? Apparently the beam slipped out from under it. Also from what elevation was the no. 10 that is seen originally? How deep could the building drive it before it got sheared off?

 

[Jeff Ostroff]

Remember that the floating K column was 12x24, but in reality, it was only 12" in the direction of the shearing forces, so it broke like a toothpick and ripped right out of that 9" first-floor slab. Remember, the column does not attach directly to the top of the H-Beam, it attaches to the 1st floor slab.

 

[MaudSTL]

The Miami Herald reports that there are No answers yet at feds’ first public hearing on Champlain Towers collapse probe.

 

[Demented]

Depending on how the plans were read, that K column should have had dowels extending 3" or 9.25" into beam 35.

That lobby level slab likely crumbled when the beam assembly twisted. Could have made it easier for the column to escape and slide down beam 35, if that is actually what happened.

 

[Reverse_Bias]

Disappointed on NIST press conference it's basically just a plan to investigate. In the mean time I think Mike Bells video gave a somewhat satisfying explanation. NIST final report is probably just going to be a much longer more detailed version of it.

 

[Jeff Ostroff]

Did nits answer any q&A from public commentary? Is there going to be a link to the video of this online meeting? I think it's a travesty to force us to register in advance by 11/3, which I missed, when it should just be a live feed like it was when we had the 2018 Marjory Stonemean Douglas Shooting Commission Meetings.
At least I was sable to secure their presentation and download them.

 

[Optical98]

Horrifying question...could they have added that column and missed the supporting beam by a foot or two?

Edit - I'm talking about the column that was to be supported, not the hypothetical one in the garage.

 

[Jeff Ostroff]

@optical99 no, you don't add a column and miss by that much. IF they added a column like this one, it looks to be about 2 feet east of the middle of the H, so doubtful they were trying to shore up the H-Beam. More likely, the column was added to shore up the first-floor level, probably under the living room of Unit #112. But still fairly close to that floating K column.

 

[Demented]

What advantages are there to this theoretical temporary concrete column that conventional steel supports cannot offer?

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

 

[AusG]

I'm under the impression a joint between RC structural elements is a designed and properly fabricated item with rebar extended in all the directions that concrete is to be poured, including upwards into the subsequent column. Having the foot of a column simply butted on a slab with no splice and/or potentially offset from the correct location is indeed horrifying and I'm expecting those who know how things are done (i.e. not me) to find it unlikely.

 

[Jeff Ostroff]

I can't think of any advantages to the column, as it is right in the middle of the east-west lane travel in the garage, although you can drive around it. So if they added this column, it would have to be for something serious, and also they would have to know there is no PILE or PIF under it. Not that is would be supporting 12 floors of columns directly over it, I suspect it would be for deterioration of the garage ceiling over that spot

 

[Demented]

Jeff, if this issue were serious enough to warrant the concrete column be cast to support the failing slab above, wouldn't the area still need temporary shoring of a more rapid method, such as the conventional steel tubular slab post shores, for the duration that the concrete is curing?

Why here, and not under the sections of deck that were in a much poorer state and at more of a risk of collapse?

 

[Jeff Ostroff]

Yes! I would have used metal wrenching telescopic shoring poles, with 4x4 wood posts up against the ceiling as most traditional people do. Maybe they thought they needed a 12x24 or a 24x24, still can't tell the intended size of the column, much less if someone was really trying to plant a column there..

 

[SFCharlie]

I don't know how constructing a column would be useful supporting the slab? If the slab was in distress, wouldn't the column just create more of a stress point? ...doesn't seem like a good way to reinforce a slab?

SF Charlie
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[Jeff Ostroff]

Charlie yes it could, but not if you incorporate a capital and a drop panel at the top of the column

 

[Nukeman948]

A far better method for a temporary shoring at that location would be a wide steel beam or two spanning the drive with steel columns sitting on the pile caps right beside the concrete columns. Less stress on the upper slab and could be braced by the existing columns. Solid foundation support, far less traffic disruption and only a days site work if you prefab at the shop. Concrete at that location would require several days completely blocking the drive with a 28 day curing time and the shoring required would be as much work as just using steel beams.

Don't wait, CALL NOW! Our Operators are Standing Buy!!

 

[SFCharlie]

Yes, Operator, I'd like two steel columns and a wide steel beam or two. Thank you!

SF Charlie
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[Roga50]

Typical example of the problem with South Florida condo's--and Champlain Towers...

https://wsvn.com/news/help-me-howard/unsafe-elevator-solution/

(notice the age of the condo board president)

Sound familiar?

 

[spsalso]

I do have to ask:

What floor does the condo board president live on?




spsalso

 

[Demented]

4th, of a different building. Because you know, FL is great.