Apartment Building Collapse 46

[dik]

"A six-story apartment complex partially collapsed Sunday evening in the city of Davenport, Iowa, authorities said. It was not immediately clear if there were any fatalities or how many people may be missing or trapped in the building.

Davenport Mayor Mike Matsen said there were "several people unaccounted for," but did not give a specific number or range.

The collapse happened shortly before 5 p.m. local time, Davenport fire chief Mike Carlsten said. The cause of the collapse was not immediately clear."

https://www.cbsnews.com/news/davenport-iowa-building-collapse/

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[3DDave]

Ah-sneaky.

 

[Sym P. le]

I believe this is a photo of the space accessed by the exterior door with the sidelight and where the May repairs are taking place. The interior finish nearest the door is buckling while the distant surface beyond the jog (and beside the desk) remains sound as the structure is reinforced by the shore post mentioned in my above post.

The image is from a City of Davenport Rental Property Complaint Inspection, July 2021.

City of Davenport

Also, another intervention (a steel beam and shore) is visible in the following image (reposted) from the first Select Structural report, Feb 2, 2023, though there is no indication of when it was installed.

Select Structural

What seems clear is that there is a broad section of wall that has lost bearing capacity through two floors, the middle half which is propped up by additional shoring and the original stack masonry.

City of Davenport, Feb 10, 2023

 

[Sym P. le]

An animated GIF extracted from the CNN video.

In light of my above posts, it seems that the north shoring post is the last impediment to the collapse. The structure weighs down on the shoring post causing masonry above it to disintegrate before the two structural masonry columns south of the door and between the window infills give way leading to the broader collapse. Although a slab of exterior wythe breaks free further south, that is only consequential to the failure at ground level.

 

[3DDave]

That no one is likely going to prison over this is the worst part. If someone crept into the building and smashed out the supports like that it would be murder. But just ignoring it? A stiff fine and some civil suits.

 

[Sym P. le]

And if all that isn't enough, how about the asymmetrical loading of the key arches above the window infills. Perhaps an historical flaw that played a role in the structure's final demise.

 

[Sym P. le]

... the worst part

I find it disturbing that work was carried out without any shoring. The exterior bracing was just there to prevent a few bricks (or more) from landing on peoples heads. I suppose that will be work for insurance adjusters and lawyers. Maybe not a billion dollar law suit this time but it won't be pennies.

 

[FacEngrPE]

Here's the latest on the building collapse lawsuits against Wold, Davenport and others Tom Loewy , Anthony Watt Aug 4, 2023, quad city times

 

[dik]

It bothers me that there were no criminal charges filed.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[FacEngrPE]

Lawyers that claim victims of a building collapse should have their claims voided due to their "contributory negligence" (living in the building that collapsed)??) belong on dik's list.

 

[dik]

They likely didn't know it was a collapse 'about to happen'. I don't suspect they had any suicidal tendencies. They, like others, rely on experts.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[Sym P. le]

Whatever the cause of the veneer slab leaning against the building, whether decay or purposeful removal, further scaling operations on either side of the door look deliberate and I'd say the crew recklessly came close to killing themselves. If all of the scaling operation was deliberate and without any shoring efforts, that would be extraordinarily reckless and given the outcome could or should lead to charges.

 

[Sym P. le]

As masonry column A looses its capacity, the masonry/shore combo of column B is overcome and the structure collapses. That's not to say that the masonry column north of the door had any further endurance, but I see column B as yielding first.

As I attempted to describe much earlier, the outer wythe/veneers are indicative of distress but are not a comprehensive description of the full cross sectional distortion. The inner wythes supporting the floor structure can yield to vertical forces while the outer wythe detaches and bulges across a greater surface area. That is to say, the structure was slowly shrinking down from the inside while the outer surface bulged out.

While the outer wythe may become detached and bulge, it still remains propping up the masonry above and pulling it out can be a fools gambit. If I'm missing one label, it's "Mickey Mouse Was Here" under column A.

Edit: Looking back at the animated GIF, the two closest windows crush as the upper floors bear down on them while their sills remain fixed. When column B fails, the second floor bridges to the stack masonry. The south portion of the second floor collapses from the impact of the upper floors.

 

[Sym P. le]

Please continue this discussion at Apartment Building Collapse - Part 2