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

[SFCharlie]

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

SF Charlie
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[FJBnomics]

 

[FJBnomics]

As fruitless as this may be, if you zoom in on the passenger rear tire of the black pickup truck, from the image Reverse_Bias posted above, it sure looks like the deck is broken under planter wall in this area, and it appears passenger rear tire is in a deeper depression of the deck. Almost like the truck is loaded with bags of Sakcrete in the truck bed or something very heavy?

Truck also appears to be parked much closer to wall than surrounding autos? It was mentioned early on, that perhaps truck hit planter wall???

 

[Optical98]

I remember asking that early on, I think even before we had the garage video.
I think at the time I thought the wall was continuous, from the bottom and that the planter being pushed back or backed into could have dislodged the slab from the wall.

 

[Optical98]

Closer images, actually that looks to be a hard cover for the truck bed that's been dented in.
But you can see the chaos of the planter box.

A better zoom into that back tire
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1643934250/tips/Park_Coll9_2_fbyrgp.png[/URL]

 

[Sym P. le]

My guess for the truck is a 2018 2500HD High Country Duramax. If so, they don't get much heavier than that. Someone else posted about the truck but I lost track of the post.

 

[FJBnomics]

Look at the top tension crack in Optical98's post...

 

[Optical98]

Sym P. le

There were some posts about a Duramax possibly hitting a column, and I always thought they meant in the garage...but yeah, it could have hit that column from above as well. I'll look thru my pics to see if there's any that show the front right fender area of it.

Zoom in>

 

[Sym P. le]

I was wondering if that slab wrapped over the vehicle below. The stalls underneath are very deep and from the garage video you can see that sometimes the vehicles are parked all the way in and sometimes not.

 

[AusG]

It's all good new input to the overall question, but we don't know what that the deck has fallen onto. Cracks in it now may be due to landing on uneven stuff (cars, etc) under it.

 

[Sym P. le]

The poster I was referring to was trying to approximate the weight of the vehicles.

 

[Optical98]

I edited my post, check the pic and zoom in...there actually is a mark on it's fender. Can't say for certain what and when.... but it's there.

 

[FJBnomics]

The more I stare at the photos around the Duramax, the more I see IanCA’s slab failure in this area, and the fact that it looks like that is sufficient to pull slab down and away from wall. It was a 2-way slab, and I think that could explain tension failures in top and bottom in same area. Planters are a lot of weight, and provide great water source. I also see failure moving South to North explaining unzipping of rebar as failure progressed North. Failure likely progressing from Duramax area traveling North and East together, like a Wave for lack of coming up with better term.

I think this fits timeline and witness statements well. Any sound in this area is close to elevator shaft, would seem to be a conduit for sound to travel to every floor.

A wave traveling South to North would create high pressure to vent thru openings like North like Parking gate.

 

[Sym P. le]

I have to agree. The evidence seems to make a sound case for the lobby parking area, if not the truck itself, to be the trigger for the collapse.

Note: the line indicated as a construction joint at the west side of my drawing is an error. The topping layer broke in a straight line but the slab beneath has not.

Zone A should also encompass parking spaces 46 and 47, and is centered on column I14.1, along with the blue ellipse being centered on column line I.

I would include space 46 in zone A and shift the ellipse to the west while also making it broader. Space 47 would likely be akin to zone B. Thanks

 

[Red Corona]

You need to be careful about looking at the positioning of that truck in these photos - that's after the deck has already settled and it looks like the car on the W side of the truck has fallen into it, it could have pushed it into the column as they both fell. Nudging into that column (which we know didn't collapse) wouldn't have caused anything to happen anyway.

 

[FJBnomics]

I think slab was already about to, and Duramax just happens to be double weight of midsize to smaller cars, so like parking two cars on top of each other. A little more weight or the last straw on camel’ back.

I feel may have been construction joint near where Duramax parked

 

[Sym P. le]

I was thinking more along the lines of the weight and live load aspects working on an inherently weak slab/column connection. That little car would be a mere fly splat on that truck.

 

[zebraso]

The damage seen on the outside of the wall at the planter is proud to the plane of the wall. What could cause that aside from a lateral (normal) force pushing south from the other side? Am I missing something?

 

[FJBnomics]

I think it is falling down under inner planter wall in IanCA’s (c) diagram above. The downward fall creates horizontal and vertical force vector components on slab.

Say rebar has failed East to West under inner planter wall, but North South has not. But under stamped concrete East West rebar has not failed.

Further I would expect a lot of stamped concrete water ends up in joint between stamped concrete and inner planter wall and keeps structural slab under planter soaked and if already sagging deck with low spot at planter wall, them gravity does the rest

 

[zebraso]

Say rebar has failed East to West...

That makes sense. Thanks.

 

[MaudSTL]

I’ve attempted to map the Parking Deck Failure Theory onto the Witness Observations from the Timeline. Please review and provide corrections to this draft.