Dome collapse

Dome in Minneapolis collapses under snow load

HHH Sports stadium in Minnesota can't deal with the snow load. The storm, while severe, is not a "storm of the century" or a 100 year only event. What did the designers think/ plan for? Snow in Minnesota should be no surprise.

That's what I thought when I first heard about it. Building a structure in Minnesota that can't handle snow would be like putting up a building in Florida that can't withstand the rain and wind of an average hurricane. It just doesn't make any sense.

The dome design appears to quite a sensible and clever design for the winter and snow conditions expected, but has probably aged quite poorly in the sunshine after getting on for 30 years old. The design has one major flaw though, as soon a tear appears in the outer fabric of Teflon coated fibre glass the whole dome structure is compromised as it will deflate as the inner and outer air pressure begins to equalise.

Building a rigid structure over such a large area designed to take 18 to 24 inch snow load would be a very expensive civil engineering design challenge.

We might even see the same thing happen to the London Millennium dome monstrous carbuncle later this winter also.

My understanding is that the snowfall was well above average, and, something unusual for the area, quite wet.

Membrane roofs are also something of a compromise. Failure under extreme conditions was likely planned and engineered to allow it to happen without serious structural damage. It isn't like the main structure collapsed. Just the membrane roof in the center.

My understanding is that they started clearing the snow off and hand to get off of it due to wind hazards. Then... pop.

Who owns the Metrodome? The state? The city? private ownership? Whoever - looks like a lawyer's dream ...

Great- first my team collapses, then their house!

The snow we just had in Minnesota was of the light dry variety due to the low temperatures, but there was up to two feet of it, and more in drifted areas. The wind speeds were 35 to 50 MPH. It is not all that unusual for the HHH Metrodome roof to collapse; it has happened four times now. The roof membranes are worn out and need to be replaced. Ziggy Wulff's prayers answered?

The collapse was caught on video from the inside:

http://blog.seattlepi.com/zennieabraham/archives/231543.asp

I'm not sure I would want to be on that roof in those conditions. If the weight of the snow is enough to need removal it is enough to risk damage and collapse. With everyone on it in danger of falling into the stadium. Add in a strong wind, anyone who has played the parachute game knows if it catches the wind it can throw you, and you risk getting tossed to the outside and ending up bouncing off the parking lot.

I suppose, if they follow the rules, there are likely harnesses, safety lines, and sturdy attachment points but that particular ride would not be my definition of fun. I've gotten too old to enjoy that game under any conditions but hanging on a line in that weather is a bit more than I'm willing to do for anything anyone is likely to offer.

When it comes right down to it if it is between getting someone seriously injured or the fabric giving up I'll go for the later. They are insured and the fabric needs to be replaced regularly anyway. Given the beer drinking and gassy nature of the fans the stadium could likely do with a little extra ventilation.

I read from one of the coaches (I think) that basically they pop the rim of the roof, pull off the cloth, and replace it. Hit the generator, it inflates, and voila! New roof.

Kind of like a big honking bike tire.

A bit on NPR said that the last time it collapsed the repair only took three days. Which is long for changing a tire but shockingly fast for such a large construction.

I wish the Vikings could be repaired so quickly!

Pop out the head coach, replace with a new one, inflate with hot air!

That's what they're trying!

Sounds like the inflatable autopilot in "Airplane".

[quote=Art_in_FLI suppose, if they follow the rules, there are likely harnesses, safety lines, and sturdy attachment points but that particular ride would not be my definition of fun. [/quote]

Actually, in wintertime Minnesota, no safety gear is needed. They just stick their tongue on a metal support, and they are firmly attached until spring.

That goes a long way toward explaining why Minnesotans talk funny.

You could learn the accent....Just repeat the word "lutefisk" with your tongue frozen to an I-beam

Why when we travel to other places they like us to say certain words?

One word: Fargo.

I grew up in a small farming community in Minnesota and parents/aunts/uncles sound just like that.

-Blast

Sound like what? Jesse Ventura