NOLA Hard Rock Hotel collapse

[pureantigravity]

There's a parking garage around the corner from me.
It's all pre-tensioned concrete beams (50 foot long sections) supporting a pre-cast/slab-sectioned floor.
The beams all sit, un-secured, on the support structure with 2" of overhang.
In event of seismic event ...
pray.
But this is going to be a mess to figure out. So much of it just fell apart it seems.

[teleee]

So.....wtf is cmu?

concrete masonry units - fancy lingo for cinder blocks

[splat]

Thanks, teleee. I thought it meant cement mixing units.

[I Skied Bandini Mountain]

The beams all sit, un-secured, on the support structure with 2" of overhang.

Please. Stop.

[::: :::]

i'm w/ telee that it doesn't look like a crane/beam induced failure
but, that said...
not really enough to go on for what actually started it with the vids not starting until the structure was already moving

be interesting to see what forensics determines...

[pureantigravity]

https://terrific-top10.com/2014/01/2...ing-collapses/

[ill-advised strategy]

Not sure if they will do a NTSB type level investigation or even who that would be other than Orleans Parish inpsections..

Private by way of insurance companies maybe?

[Micol]

I doubt the beam and or crane had anything to do with it. First the structure started to collapse on a corner, a long ways away from the location of the structure that the red iron was constructing. Second, the beam appears to already be bolted off, making it impossible to be subjected to load spin. Again, a whole lot of speculation based on a few youtube photos. But, I have been around cranes and construction my whole adult life, and put myself through college in the seat of a crane, and my structural engineering degree (and staying in a plethora of Holiday Inn Expresses) point to this being something different. I would love to review the design calcs on this.

i knew we had some pros in here (and you other guys that chimed in)....good info...
take a look at some of those attachments to the NOLA paper article...maybe find something in there that might be helpful

[Micol]

Private by way of insurance companies maybe?

true that

[MultiVerse]

OSHA is participating in, and maybe even heading up the investigation.

[Micol]

OSHA is participating in, and maybe even heading up the investigation.

i completely forgot about those guys/gals....

[::: :::]

nerd forum here -- with some images not offered in the news, incl dtls

https://www.eng-tips.com/viewthread.cfm?qid=459166

[Micol]

nerd forum here -- with some images not offered in the news, incl dtls

https://www.eng-tips.com/viewthread.cfm?qid=459166

off the subject......wonder if that place is as fun as here or moderated

[Micol]

that p.e. forum yielded this little piece of info....which may have absolutely nothing to do with this situation...but interesting non the less....
Head of building inspections put on suspension last month for corruption investigation....

https://www.nola.com/news/courts/art...3619becbf.html

[Danno]

off the subject......wonder if that place is as fun as here or moderated

an engineering forum. fun. hmmmm.

[Micol]

an engineering forum. fun. hmmmm.

haha

but on serious side....they've got some sets of plan sections and callouts and its getting pretty detailed in there....also the lack of experience in prior like/similar projects by the structural engineering firm (smaller co) and the contractor .....being brought up.....

topical summary review .....in case you dont click it...

[SorryBro]

Please. Stop.

QFT

If you don't have experience in engineering/building, your (puregravity) wild (dumb) speculation only adds confusion to a very sad situation. Be quiet, read the eng-tips link, and come back with an actual question, not a statement that you know nothing about. Actual engineers are giving their opinion rather than dentists.

This building was constructed of concrete over pan deck floor supported on steel beam/columns bearing on a post tensioned transfer slab. Very typical design for a building of this height. What caused the collapse? No one has a clue at this point.

I will agree with telee that I don't think it was anything due to the crane or impact loads from the crane hoisting beams into place. If I was forced to guess, improper temporary shoring and possible overloading due to construction loads (pallets of cmu, etc). We just don't know at this point and probably won't for years.

Everyone should keep in mind that no one involved with this is sleeping right now. The stress the design/construction/ownership teams has got to be through the roof. Knowing your mistake (know or unknown) has killed people is something that must burn into your soul.

/rant

[pureantigravity]

Guy that took video says the wind was notable
- he does mention it as something that stood out in his mind.
I think a wind caused crane issue, interacting with the steel framing up top, could very well be a point of investigation.
Twisting of the crane structure, transferred to the building, is a force that is hard to resist because
the building isn't designed to take that any time, esp when under construction.
But I doubt it is wind cause. Unless a load dropped or shoring came loose .... or
1,000 other causes that an armchair dufus could come up with.

Question though:
Does PT (post-tensioned) concrete act like carbon fiber structure (under load) when it breaks?
I mean, is the result of small failure in post-tensioned concrete likely to result in a more catastrophic failure than the same
structure designed with just reinforced concrete?

With the recent bridge collapse in Spain (Italty??), are we seeing a more skeptical view of tensioned concrete structures?

[pureantigravity]

QFT

If you don't have experience in engineering/building, your (puregravity) wild (dumb) speculation only adds confusion to a very sad situation. ...
/rant

Sure. Why don't we wait for actual qualified engineers to comment. Oh wait, they won't. I think it is in the professional designation code to not comment on such matters or else
loose designation or be fined.
Correct me if wrong.

[teleee]

QFT

IEveryone should keep in mind that no one involved with this is sleeping right now. The stress the design/construction/ownership teams has got to be through the roof. Knowing your mistake (know or unknown) has killed people is something that must burn into your soul.

/rant

Amen, I cant imagine anything worse. I have had people killed on a job site and it is the worst thing possible and will change you forever.

[abraham]

Sure. Why don't we wait for actual qualified engineers to comment. Oh wait, they won't. I think it is in the professional designation code to not comment on such matters or else
loose designation or be fined.
Correct me if wrong.

Your posts are literally bracketed by comments from people qualified to talk about this.

[SorryBro]

Sure. Why don't we wait for actual qualified engineers to comment. Oh wait, they won't. I think it is in the professional designation code to not comment on such matters or else
loose designation or be fined.
Correct me if wrong.

This will be my one and only reply to you. You are wrong. There will be a full investigation (OHSA, as well as city, county and national jurisdictions) into the causes of this tragedy. Many experts will review every piece of evidence and state their opinions. At that time, we can all review the report (the many, many pages of it) and might have a better understanding on what happened. Until then, your "is the result of a small failure in post-tensioned concrete..." comments have no basis. You didn't read the eng-tips thread. The post tensioned transfer slab DID NOT collapse. Sigh.

[iceman]

We're gonna need AvE to weigh in and tell us what happened like he did in the Seattle crane collapse incident:

[east or bust]

Who else read through the engineering forum thread? Interesting stuff that is backed by more than has been laid out here, but still speculative at this point. Though there does seem to be some compelling data to support inadequacies in the design, under the assumption that the permit drawings were not altered before being RFC’d. Which is a big assumption to make.

[beaterdit]

To my untrained mind, the crane pulling up on that red steel beam and leveraging things it was bolted to seemed plausible. In one of the linked videos though, you can see that beam spinning freely ie. it wasn’t bolted to anything. The reason it butts up to the other beam in every aftermath pic is that’s just where it ended up, resting against the other beam.

Anyhow, this sucks, as bad as three people dying is, I’m glad it wasn’t MUCH worse.

Also, I am not an engineer.