Hard Rock Hotel under construction in New Orleans collapses... 119

[Ingenuity]

Well the crane implosion did not seem to go exactly as planned:

 

[OHIOMatt]

It would seem that the situation is now more precarious than it was before the charges went off.

I am no expert on demolition like this, so I will leave my comments to the experts, but the cranes did not appear to melt away, as we described prior to the blast.

Typically this work takes months of planning. Maybe trying to do this in a few days was asking too much.

 

[bones206]

The way that one crane impacted the roof framing, they are lucky they didn’t trigger another collapse.

 

[JStephen]

Video of the crane demolition:

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

At this point, I would be inclined to request the army to send a tank over and see if a few strategic shots couldn't improve the situation.

Reminds of a quote from long ago, recited as best I remember it:
"There was a fire in the hotel. It was a 3-story building, and old man Hawkins was trapped on the 3rd floor. None of the ladders in town were long enough to reach him. With great presence of mind, I shouted "Fetch me a rope!" and presently, somebody brought me a rope. I threw one end up to old man Hawkins and said "Tie it around your waist!" He did so, and I pulled him down." (Attributed to Mark Twain)

 

[JohnRBaker]

One out of two ain't bad ;-)

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

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

 

[JAE]

The one on the left ended up on its "head" but still vertical - apparently on the street below.
Now they just need to saw the bottom off at an angle so it properly falls in line with the street and not diagonal into adjacent buildings!

 

[ausa]

What made traditional crane disassembly methods more dangerous than the controlled explosion route? General instability of the structure?

It would seem a lot would have to go right for the implosion route to go off without a hitch. Can anyone speak to normal success rates?

 

[Ingenuity]

In the post-implosion press conference this afternoon Mayor LaToya Cantrell stated:

"We want a complete demolition," Cantrell said. "That’s our focus, and that will be our mission."

I thought they may have preserved the first 8 levels of PT concrete construction (assuming adequate structural assessment etc), but I guess such preservation may come with 'bad vibes' for what holds of future use.

 

[ggcdn]

I dont understand why they didn't take off the crane booms the 'normal' way, with another mobile crane. Too risky? Riskier than an explosive demolition?

 

[NOLAscience]

It would seem that the situation is now more precarious than it was before the charges went off.

I am no expert on demolition like this, so I will leave my comments to the experts, but the cranes did not appear to melt away, as we described prior to the blast.

Big improvements:
(1) The Iberville St crane is essentially down, as planned
(2) BOTH counterweights are down; the booms are no longer turning in the wind;
(3) The Canal St crane is now just a tower and a bent boom, which can probably both be removed piece by piece, and they are probably in a fairly stable configuration, especially with a little help from temporary supports

I dont understand why they didn't take off the crane booms the 'normal' way, with another mobile crane. Too risky? Riskier than an explosive demolition?

There was no longer reliable support for the towers, especially for the Iberville St crane. Remove the counterweight and what will happen? Remove the boom and what will happen? Way too risky and would take weeks. Nearby businesses, including the Saenger Theater, have been closed for a week. People were unable to live in their homes (maybe still displaced??).

I think the mayor is wrong to want complete demolition. Why throw away 8 floors of post-tensioned concrete? Build a better building on top of that, but NOT another hotel!

 

[Ian8689]

Something else to note per S1.0A "FLOOR DECK SHALL BE SUPPORTED AROUND ALL FLOOR OPENINGS AND COLUMNS." I'm sure this is standard boiler plate but when it come to litigation and placing blame the attorneys will argue the SHALL was not done.

 

[Tomfh]

Wow. That’s one way to get rid of some cranes.

 

[Retiredat46]

The demo guys had one chance to get it right the first time...and they blew it.

I'd like to know how far the top section of the tower on the left is buried in whatever it landed on. Talk about sticking the landing.

 

[Retiredat46]

Well, the chief of the NOFD says it went pretty much as expected. It did damage a sewer line, but that was planned for. The news video shows that most of the tapered section of the tower above the boom is buried in the street, and the now-inverted upper part of the tower appears to be stable.

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

It's a looong video. The good part starts around the five hour mark.

 

[MTNClimber]

Impressive considering they avoided the catenaries for the street cars.

 

[XR250]

It's tragic that lives were lost in this collapse. So many aspects of the structural design are extremely questionable. However, I imagine if this structure did not collapse now, it would have later when potentially filled with thousands of patrons. So maybe a bullet was dodged.

 

[itsmoked]

Or, rather a bullet wasn't dodged but the artillery shell was.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[3DDave]

They speared the crane tower into the street. Like a giant lawn dart. Pretty sure that was not planned for. Also it seems like no one did a dynamics simulation for blasting or they would have not have blasted the towers until the initial motions had completely stopped. Instead they flipped a big part of the crane off the property, thankfully missing hitting anything else.

Still, as mis-planned events go, it could have been worse.

 

[hpaircraft]

The demo guys had one chance to get it right the first time...and they blew it.

There were a lot of random factors to the way the towers were damaged in the initial collapse, the situation was steadily deteriorating, weather was coming in, and there wasn't time to do exhaustive analysis they way you'd do with years or months to spare. Personally, I think they played the hand they were dealt about as well as might be expected, and it turned out way better than it could have. Nobody else was hurt, property damage was held to a dull roar, and the situation was made a lot more stable.

 

[miningman]

I cant help but wonder how many of these monday morning quarter back players, have ANY blasting experience whatsoever.