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

 

[gte447f]

They are playing with a symptom and missing the problem.

It seems so.

 

[Sym P. le]

Your Title image is a prime illustration for the analysis of the collapse though I don't think you're quite on the mark in your latest video. The collapse isn't distinguished by the falling of the exterior facade, rather it is the collapse of support for the second floor, i.e. the inner wythes on the first floor, from which everything else follows.

If I'm not mistaken, the original structure used brickwork to support the second floor. East/West steel beams extend to the west perimeter and are encased monolithically with the second floor slab, all of which bear on the inner wythes of the west perimeter wall. I believe there are three or four wythes, one of which is the exterior facade. The exterior facade is tightly tied to the inner wythes, not utilizing air gaps as we do today. This is noticeable on the higher levels where the original brickwork is still present but falling apart, i.e. no gap where exterior facade falls away from inner wythe.

What your Title image shows brilliantly are the failing inner wythes. To the right of the door, the layer of remedial facade (not original) has fallen away revealing the decripit inner wythes, upon which the building rests. Yes, upon which the building rests! To the left of the door, the whole section has dropped as though a layer of brick work has crushed and the window frame next to it is deflected. Further to the right, the CMU's may not be picking up any bearing weight since the original distribution was directed between the window openings.

Evidence of deterioration of west wall support for the second floor is well documented. Unfortunately, all evidence reflected in the deterioration of the exterior facade has distracted from the root cause. As the second floor dropped further and further, efforts were misguidedly spent on patching up the exterior blemishes without turning adequate attention to shoring up the structure and repairing loss of functionality of the inner wythes.

It is true that the exterior facade has suffered badly from weathering and is a big problem, but that is not the direct mechanism of collapse, nor a myriad of bulges and air gaps. Watching the exterior for first signs of collapse is merely to say, where is the collapse first reflected in the exterior layer. The collapse initiates with loss of support for the second floor, i.e. the sections illustrated in your Title slide cease to function.

In my NEST animated GIF above, you can see the section of brick to the right of the door spill out. This is critical supportive material and the dying breath of the structure.

All the best and thanks for your work.

 

[Tomfh]

Way too much hindsight bias in this thread. It’s not right to conclude that the engineer was incompetent and/or corrupt, or that this major failure should have been obvious beforehand.

 

[jerseyshore]

It's always wild to see these things because building don't fall down. Until they do.

I think pham once again nailed it above. I mean how many really bad beams have we all seen before in a building? Bad columns? Bad walls? Bad overall structures. Thousands. But let's be real, they are only sending us to look at the bad ones. However, the failure rate of a building structure in service is incredibly low. Just a handful a year even make semi-national news. Telling an owner or town a building has to be evacuated and shut down immediately is a high risk professionally with little precedence.

I also agree with Tomfh; it is very easy to have hindsight and criticize after the fact when there's a good chance any one of us has inspected or evaluated a building in the past year in just as bad or worse condition. But those buildings didn't fall down. Because buildings don't just fall down...

 

[spsalso]

Very well said.


spsalso

 

[dik]

I'm not so sure... looking at the condition of the exterior wall, prior to collapse, would not have provided any assurance of stability. He should have done more. People died because he didn't do anything. Same thing I observed with the repairs to the Florida condo that collapsed. The repair detail showed 3/4" conc cover for concrete in a ocean salt environment. My first thought was about the qualifications of the engineer that spec'd that. I'm not used to seaside environments, but have likely designed over 40 parking garages in the last 50 years. I would have know better.

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

-Dik

 

[IRstuff]

The static photos are SCARY Gaps and broken brick in a load-bearing wall would give me nightmares to live there.

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

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

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[dik]

Even walking by it on the street would have raised some concerns, and I would have immediately contacted the building department, just as a concerned citizen.

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

-Dik

 

[Tomfh]

I'm not so sure... looking at the condition of the exterior wall, prior to collapse

That’s how hindsight bias works.

 

[gte447f]

Way too much hindsight bias in this thread. It’s not right to conclude that the engineer was incompetent and/or corrupt, or that this major failure should have been obvious beforehand.

Maybe I missed something in this thread, but I don't think anyone has concluded that the engineer was incompetent, and certainly not corrupt. Luckily this forum has no bearing on the situation.

And I don't think it is necessarily hindsight bias to question some of what we have seen. Some of it certainly seems questionable. But, you are right that it is important to realize that none of us had first-hand, real-time knowledge of the situation as it unfolded, and so we should temper our analysis.

I will say that I cringed as I read through the most recent engineer letters, directing the repairs that seem to have been underway when the collapse happened. It seemed to be a very serious, essential, and critical structural repair to be undertaking with just a few letters and sketches, most especially because the building seems to have been occupied by tenants going about their normal lives. Here's a question (food for thought): should it be regulated that complete replacement of major structural members supporting occupant loads (multiple floors in this case) should not be permitted for an occupied structure? In other words, should there be a mandatory evacuation in such cases?

I certainly empathize with the engineer involved, because I have been in similar situations myself and faced similar decisions about what to do in cases of major structural deficiencies and repairs to buildings occupied with tenants. In hindsight, I would probably make different decisions now in some of those cases than I did at the time. It's a tough spot to be in.

 

[dik]

If I was in the area, and came across the condition, I would have raised a flag. This was more than a simple defect.

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

-Dik

 

[Murph 9000]

I will say that I cringed as I read through the most recent engineer letters, directing the repairs that seem to have been underway when the collapse happened. It seemed to be a very serious, essential, and critical structural repair to be undertaking with just a few letters and sketches, most especially because the building seems to have been occupied by tenants going about their normal lives. Here's a question (food for thought): should it be regulated that complete replacement of major structural members supporting occupant loads (multiple floors in this case) should not be permitted for an occupied structure? In other words, should there be a mandatory evacuation in such cases?

That could possibly introduce a risk of further delaying or reducing the scope of important maintenance. It might be necessary in some cases, but excessive in others. A better approach might be to mandate that the work be carried out under the direction and supervision of an engineer, following a detailed plan of work that accounts for properly supporting the structure and managing risk as the work progresses. It seems to me that part of the problem here is that the building owner apparently tried to do the work on the cheap, without a formal detailed plan, and the chosen contractor was significantly out of their depth with no proper supervision from an engineer. Have the plan properly approved by the city/county engineer, and let them pass the final judgement on whether a temporary evacuation is required.

 

[gte447f]

Murph9000, the things that you suggest appear to have been in place for this particular collapse, and yet it still collapsed. The work was being done per the instructions of an engineer (notwithstanding apparent deviations from the engineer's sketches for the shoring). The city/AHJ seem to have been perfectly well aware of the issues and seem to have been involved in the process. In fact, I suspect the engineer may have even been working for the city rather than the owner. I don't know this for a fact, but it is not clear to me who retained the engineer. His letters were all addressed to "To Whom It May Concern". The only thing missing from your suggestions is a "detailed plan of work that accounts for properly supporting the structure and managing risk as the work progresses", but don't you think that is probably what the engineer involved thought he was doing and what everyone else involved thought he was doing in this case? The only reason we know that this doesn't appear to have been the case is because the building collapsed. But that is kind of my point, a few letters and sketches may not have been enough to address the seriousness and the magnitude of the issues involved in this case. However, I don't think that a non-engineering bureaucracy (i.e., the city/AHJ) should be able to judge and dictate what constitutes "detailed plan of work that accounts for properly supporting the structure and managing risk as the work progresses". If the engineers can't be trusted to do this, then it may need to be codified (e.g., building codes).

I do agree with you that it appears that the contractor in this case may have been beyond their depth, although they may have been very knowledgeable and skilled at their trade. I think they were a masonry company, a specialty trade contractor, not a licensed general contractor. As I was going through some of the documents on the AHJ web site linked above (I did not go through them all), I came across one email exchange between someone at the city and someone at the masonry contractor that seemed to be discussing the requirement that a building permit was required and assisting the masonry contractor to obtain a general contractor license in order to be able to pull the necessary permit.

 

[gte447f]

Wow. I just looked through all the documents posted on the Davenport Iowa website. Tons of complaints and violations for this building in just the last 3 years. The docs paint a picture that this building was a slum and a ticking time bomb.

 

[JohnRBaker]

Over the weekend, the bodies of the three remaining heretofore missing individuals were found in the collapsed portion of the building. According to city emergency officials, this now accounts for all known residents of the building.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[gte447f]

A sad outcome.

 

[phamENG]

In other words, should there be a mandatory evacuation in such cases?

This is my standard in cases where I'm looking at a damaged building. If any shoring is required for any reason, I instruct the owner/contractor/whomever to 'remove all live load from the affected spaces and tributary areas of members to be supported by temporary shoring." I then explain what that means in case they don't know.

 

[dik]

We'll see how this flies...

https://www.cnn.com/2023/06/06/us/davenport-iowa-building-collapse-tuesday/index.html

I still think the owner should be charged with negligent homicide...

From another article, "“The owner of this building was aware, the city of Davenport was aware, the engineering companies and construction people were aware. This was a completely preventable tragedy,” said attorney Andrew M. Stroth, who is representing Peach and Lexus Berry."

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

-Dik

 

[dik]

Filing...

https://s3.documentcloud.org/docume...ding-owner-and-city-after-deadly-collapse.pdf

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

-Dik

 

[Sym P. le]

Ryan Shaffer (R.A. Masonry) interviews

WQAD8 abc

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