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

 

[bones206]

I appreciate the legwork the youtubers put in. I watched Jeff's video and was able to absorb a lot of the timeline and background of this building in a few minutes, which I do value. The more speculative and opinion-based portions of the video I found to be a little strident and presumptuous. I do value the presentation of facts, but there is a whiff of clout-chasing and personal promotion sometimes that makes me cringe, especially with fatal tragedies like this. On the other hand, it's natural for people to try to understand why something happened and dig into it, testing out hypotheses with open source evidence and discussion with peers. Just think it should be tempered with humility and transparency, probably in the form of a disclaimer regarding professional credentials.

If these kind of videos are crossing an ethical or professional line, I would expect the relevant government bodies to address it as they deem necessary.

 

[fel3]

Jeff:

You said, "Well, then why is this web site allowed to be up? why is anyone here in haste allowed to post pictures and diagrams here an give opinions? If mac is right this whole eng-tips needs to be shuttered." I strongly disagree.

In the United States, at least, this entire discussion is protected by the First Amendment (assuming no actionable slander or libel or a few other special cases that don't apply here). Eng-tips.com as a whole is also protected for the same reason. You are advocating censorship, which is most often how truth is suppressed. In fact, the free and open discussion of events like this is generally beneficial, especially within a knowledgeable group like we have here.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[Murph 9000]

I don't think Jeff was advocating censorship. I interpreted his comment as being in favor of free speech and healthy academic discussion, and against Mac's quite inappropriate position that it's inappropriate for people to discuss and analyse engineering failures on the Internet.

 

[dik]

Education beats censorship every time...

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

-Dik

 

[fel3]

Murph…

You may be correct. Unfortunately, sarcasm doesn't translate very well to text.

============
"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

 

[IRstuff]

Let's not forget that Jeff is ostensibly the same Jeff on YouTube with their video about the collapse, so I'm certain they're not advocating censorship.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[dik]

There needs to be a 'Sarky' font... maybe something like Wingdings?

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

-Dik

 

[JAE]

The owner of the building, Andrew Wold, pleads guilty. Huge fine! (snark).

https://www.kwqc.com/2023/06/12/wold-pleads-guilty-not-maintaining-safe-conditions-davenport/

 

[JAE]

Also:

[blue]8 a.m. June 14 - 2 companies brought in for cause and origin report
According to the City of Davenport Chief Strategy Officer, Sarah Ott, the City of Davenport has engaged the Chicago-based White Birch Group, LLC and SOCOTEC Engineering to conduct a cause and origin report on the partial collapse of the building at 324 Main Street.

Both firms are highly regarded and have considerable experience in this type of investigation, Ott said. The time the assessment will take is unknown, but the completed report will first be shared with relevant agencies and oversight authorities.[/blue]

 

[JAE]

Demolition started:

 

[Sym P. le]

It looks like they're struggling to contain the process, encroaching on neighbouring structures, lower right.

Also, time lapse video of demolition Day 2, Youtube.

 

[Red Corona]

Joshua Porter (Building Integrity) has an excellent one up about this collapse, with a sequel coming soon

The sequel is now out:

https://www.youtube.com/watch?v=ydjZ7J3-JuQ

It's quite a good watch, the tl;dw seems pretty simple to me though: the people planning and executing the "fix" in Feb this year did not understand that the brick wall was load bearing, the "fix" did not adequately replace the load capacity of the damaged wall section they replaced, and the remaining load bearing wall nearby on the ground floor became overloaded as a result.

(Not mentioned in this vid but this seems to have continued right up to the facade shoring - as you guys pointed out above, the shoring on that wall at collapse time is clearly only targeted at keeping the facade on, not taking any meaningful load from the building itself.)

There were also clear signs of major problems well before the actual collapse. It's actually pretty impressive how brick structures fail slowly and safely for a long period (weeks). The level and speed of deformation should have had this building evacuated well before collapse.

 

[Sym P. le]

Josh is blowing a lot of hot air in the first half at least. The exterior wythe (brick) was structural though earlier repairs appear to have been cosmetic, masking a crippled structure with a substructural veneer (reference my earlier sketches).

The engineer supervised repairs in Feb. properly addressed structural concerns and those repairs were successfully implemented, even withstanding the collapse.

My attention piques when a d.i.y. owner with dubious qualifications and abilities undertakes the complex and dangerous task of furthering the urgent repairs. We don't know if the crew was even capable of following an engineers instructions, and it appears not.

I don't believe the engineer is to blame for this collapse though he might have been diligent to raise the urgency of the hazard. I'll leave that judgement to appropriate review.

P.S. last half of video is just more hot air.

 

[Sym P. le]

A much better take on the collapse by Mike Bell, following up his previous video.

Youtube

 

[FacEngrPE]

Load bearing brick walls at least thee ones I am familiar with do not have non load bearing veneer. Even if the structure has survived the repair effort it would still be at risk if the outer layer was not secured to the core. 100 years ago this would have been done with masonry mortar, sometime with tie bricks. Now there are more options.
There are no substitutes to proper shoring to divert the loads around the repair area.

https://www.wqad.com/article/news/s...uits/526-3fa12c49-0d83-4536-8486-fffb1b85b4a0

As of June 6, six lawsuits in play, one being a class action, and one claiming Mr Wold's LLC was an attempt to avoid liability and commit fraud on the city and tenants. Select Structural Engineering LLC, Bi-State Masonry Inc. and the City of Davenport and others are named.

 

[dik]

What is missing is the criminal negligence of the owner and lack of engineering input (he was the expert that everyone was relying on)... people died because of it.

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

-Dik

 

[Sym P. le]

From an inspection report by Select Structural (May 23/24), a clue as to why this structure failed in stages, ... the piecemeal approach to rehabilitation. A shore post can be seen behind the interior finish, obviously an earlier reinforcement, perhaps dating as far back as 2011.

Select Structural

Google Maps

Random interventions cause disconcerting external symptoms alternately between the ground floor and second floor, though the bearing capacity has in fact failed throughout.

Select Structural

Relevant to the discussion, from NCMA (this structure has five wythes whereas the article only references two):

- Composite walls are multiwythe walls where both wythes act structurally as one unit. They depend on sufficient stress transfer across the joint between wythes for composite action.

- To ensure shear transfer, Building Code Requirements for Masonry Structures requires that the joint between wythes ... be crossed by connecting masonry headers.

- Although allowed, the use of masonry headers is an outdated method of connecting masonry wythes and is not recommended for several reasons. Headers are less ductile than metal wall ties, making accommodation for differential movement a critical issue. Differential movement can shear the headers, effectively eliminating the composite action, particularly with the combination of concrete masonry and clay masonry wythes. Also, walls bonded by headers are also more susceptible to water penetration.

The west masonry wall was e.o.l., being so fractured as to not carry a load throughout its cross-section as intended. The elevated floors/structural frame only rested on the innermost wythes while decay attacked the structure from inside and out. Structural support is only derived from the masonry between window stacks and the lower most floor is least capable as commercial light demands greater prominence and impinges on this space. Infilled windows are not necessarily adequate structural enhancements.

Although Select Sturctural called for additional shoring in four foot increments during earlier winter repairs, there is no evidence that the owner provided same during May repairs (May 25).

City of Davenport

Meanwhile the horrific state of decay revealed itself as the external detached wythe/veneers fell away ... a few days later!

The structure collapsed on May 28, 2023.

My condolences to those whose loved ones were lost.

 

[enginesrus]

It looks like that building should have been a demo project 20 some years ago.

 

[3DDave]

That doesn't look like a shore post - just the studs to cover the old opening. It appears not to touch the beam above.

 

[Sym P. le]

That doesn't look like a shore post - just the studs to cover the old opening. It appears not to touch the beam above.

This shore post, behind the steel stud and still there two days later.

City of Davenport

Edit: The timestamp is a little suspicious as the photographer would have been very busy at 7:54:52. Not even Santa Claus could accomplish so many photos at once.