Metrodome Roof Collapses?

[Babalonian]

 

First of all, all I said was "engineering fail".  That is such a broad based comment I don't know why you are epically ranting over this.  I could have meant the engineering of the fabric, or the engineering of the heating system, or the engineering of the roof.  I honestly have not even looked into it at all other than this thread and the general news articles.  I'm sorry for inferring that the structural engineer might have been to blame.  Are you a structural engineer?  I'm not, but I will be in about 3 years after I graduate with my M.S. in Structural Engineering, and finish up my work requirements to get licensed in my state.  Anytime you want to talk loads, codes, dynamics, structural reliability, concrete design, steel design, masonry design, wood design, seismic design, etc.  Let me know. 

We're looking for tensile strength here mate.      I'm not a licensed or formally edumacated civil and hydrolic engineer (I'm what you'll soon come to affectionatley reffer to as a CAD monkey (AACADD graduates), but I deal with the stuff 5-days a week and either the state OSHPOD or local/county Building and Safety inspectors and permits about once a week (and those overseeing department's codes and ordinances roughly only about 20 times an hour).  Most of the standards you're learning in school are derived from the ordnances and codes that are overall the national standard, just a few things different here and there (IE: here in So Cal, you can throw out just about everything in school you'll learn about winterizing and distributing snowfall loads, but you'll be brushing up on and regularly frequenting topics on seismic safety, non-potable reclaimed water, rain-water retention systems, bio-filters for rain runoff, etc., etc.).

Make sure you take some project management cources while working on your degree in school, it'll really help you land a great position quicker out of school... otherwise there's a good chance you might be placed out of school as a subrodinate to some poor overworked and vindictive CAD monkey like me.  

[Babalonian]

Building code

   whatabout it, I said it would/should of never been built in the first place if it didn't at least meet the minimum state and local codes and ordnances, baring a specific waiver issued by them for it.  It's like a state-issued drivers permit, you have to meet the minimum requirements and get issued a permit, else it's illegal for you to ever drive and making you 100% liable for any accident or failure that occurs as a result - your fault or not.  The state is only liable if they issued a permit to someone unfit or that fails to meet the requirements, or in this case if they issue a building permit for a set of plans that doesn't meet the codes and requirements the permit requires them to.

They engineer things that meet or exceed the specifications of the designer/owner(s) that then must comply to or exceed the state and local code and ordnance requirements (building codes).  Assuming they didn't get away with constructing the roof of the Metrodome without a permit, and the construction of said roof met or exceeded the plans and specifications issued to the contractor, it's the fault of whoever at the state or local government level noded their head to the plans and put the stamp of aproval on it.

This is where my frustration kicks in, it's that people think this was as professionaly constructed as your neighbor's backyard shed, and that since the roof colapsed then it must be the fault of the nupty who engineered and built it.  I spend a great deal of my profesional time having to "demonstrate, without any reason of doubt, to the state/local ____ inspector/permit-issuer, that everything within the scope of work being proposed meets or exceeds all requirements"... my usual frustrations kick in where state and local beurocracies meet the "without and reason of doubt" line (IE: a datum table displayed verticaly is denied for resubmital just because the inspector wants it in a horizontal format... stupid stuff like this happens often, and despite complaints they are in their full right to).
Something here went very wrong, and likely not at the level of the engineer who, unless there was some taboo under-the-table nagotions going on with the inspectors and the engineers/designers, likely met or exceeded what was specified to him.

As I said before, I'm guessing this was a failure of maintenance or operational procedure.

[Babalonian]

Wrong.  Any structural engineer that designs to the customer’s specifications and neglects the governing codes will not be an engineer very long.  It is the responsibility of the engineer to protect the public even if that means the customer has to cancel the project because they are not willing to cover the cost.  I don’t know all of the details related to this case so I will withhold my opinion, but I will say that the roof should have been designed according to the local and state building codes which would allow for a snowfall like that roof just experienced.  If the engineer didn’t do that, they are very fortunate nobody was hurt and they deserve the lawsuit that is heading their way.      

SunBat, P.E.  

There is no way an under-engineered roof of the frakin Metrodome would of gotten constructed without at least a couple building permits issued from the state.  If the roof did not meet those requirement but was issued a permit (aka: permission) then it is the state's fault, or rather, not the fault of the structural engineer, as the state said it was OK and fit the bill and standards.

I don't personaly know of a structural engineer that would of touched this idea with a 100-foot ductile iron pole, but owner-representing value engineers are another matter.

[Babalonian]

Also Sunbat, did you know a guy named Gerhardt Kramer? (I think thats how you spell his name) He builds geodesic domes and was in new braunfels building one.

You reffering to the same Gerhardt Karmmer at Langdon Willson here in LA?

[Dichotomy]

Well the three PE's I talked to in the last couple of days all said the same thing.  'I'm glad my stamp wasn't on it'.  The poo is going to fly far and fast and it will stick to as many people as it can. 

And Bab.. CA building codes are so whack that I cringe every single time one comes across my desk. 

When the big one hits the light poles will be the last things to go

[68ZooM]

There is no way an under-engineered roof of the frakin Metrodome would of gotten constructed without at least a couple building permits issued from the state.  If the roof did not meet those requirement but was issued a permit (aka: permission) then it is the state's fault, or rather, not the fault of the structural engineer, as the state said it was OK and fit the bill and standards.

I don't personaly know of a structural engineer that would of touched this idea with a 100-foot ductile iron pole, but owner-representing value engineers are another matter.

Bingo, i design homes and some commercial buildings at times , the plans will not be passed without certified engineered spec's that must meet or exceed  ALL  State, County, and City structural codes, once passed it's Safe for the Public to occupy, and with that Roof System i'm sure they kept a good eye on it's construction, now you get into the did all the materials used in construction meets the Spec's ? , they must have or they never would of passed all the inspections during its construction OR did something happen with the climate control system that prevented it from supplying enough warmth into the Roof to keep the snow from accumulating on the Roof, there's going to be alot of finger pointing until this is all said and done

[Dichotomy]

Zoom are you a Civil or a PE?

[grizz441]

We're looking for tensile strength here mate.      I'm not a licensed or formally edumacated civil and hydrolic engineer (I'm what you'll soon come to affectionatley reffer to as a CAD monkey (AACADD graduates), but I deal with the stuff 5-days a week and either the state OSHPOD or local/county Building and Safety inspectors and permits about once a week (and those overseeing department's codes and ordinances roughly only about 20 times an hour).  Most of the standards you're learning in school are derived from the ordnances and codes that are overall the national standard, just a few things different here and there (IE: here in So Cal, you can throw out just about everything in school you'll learn about winterizing and distributing snowfall loads, but you'll be brushing up on and regularly frequenting topics on seismic safety, non-potable reclaimed water, rain-water retention systems, bio-filters for rain runoff, etc., etc.).

Make sure you take some project management cources while working on your degree in school, it'll really help you land a great position quicker out of school... otherwise there's a good chance you might be placed out of school as a subrodinate to some poor overworked and vindictive CAD monkey like me.  

Hah, well thx, I have an engineering position at a consulting office too, I'm not just going to school.

Thx for the tip on tensile strength, I'll look that one up, never heard of it before.  Hopefully I can also learn how to draw a shear and moment diagram while I'm at it.   

[SunBat]

I love it when CADD monkeys try to talk engineering. It's cute.

SunBat, P.E.

[Masherbrum]

Here's more things to nibble on: "Maki said he had about seven workers on the roof Saturday, blasting hot water with fire hoses to get rid of the snow."

http://www.startribune.com/sports/vikings/111730439.html?elr=KArksi8cyaiU9PmP:QiUiD3aPc:_Yyc:aUjEkD_hEK_kchO7DU

Ice + some of the wettest snow I've seen in 37 years.   Again, the roof was screwed from the get go in this storm.    Maybe they'll remove the dome and use it as an open air stadium.

[68ZooM]

Zoom are you a Civil or a PE?

if your refereeing to an engineer, no i still would have a couple years left for that degree, I've been mulling that over ever sense the housing market took a dump, but 2 years structural design, then 2 years working with Bill Clemens Jr a former Oregon State Building Offical been in Structural engineering for the past 30 years, when the WTC went down he was part of the investigation team that studied what was left, anyway under him i would do all the drawings of the homes and commercial buildings into final form and Bill would do the engineering, run the calc's , sheer loads, beam sizing, ect, all the good stuff them guys get paid the big bucks for     i should go back and finish, liked designing structures  

[Dichotomy]

I've thought about it Zoom as I pretty much 'get' all of the codes I have to deal with.  Been dealing with them off and on for 15 years.  If you've only got two to go you should imo.  My industry could use more people with common sense. 

Hmmmm.. this is getting interesting.

Okay pop quiz for all of the enginerds out there.

You have a supporting structure originally designed with an embed depth of 10 ft of 65 ksi steel (galvanized and mastic coated ((industry standard depth and protection)).  The PE of record recommends, due to soil conditions, a drilled caisson of 12' depth 18" OD to 6" above ground level.  The contractor calls and wants to backfill with #7 rock and soil instead of pouring the caisson or cold jointing it so, in the future, he can get to his below grade wiring. 

What's your answer?

I'll reserve mine because I already know it. 

[68ZooM]

yea i should go finish it out, I've been in the construction field for about 26 years, last 17 was heavy equipment operator , doing all phases of earthwork, residential, commercial, logging road construction, safeways, freddie's list goes on when i had my injury in 2000 that's when i was told heavy construction carrer was over and i had to look for something else, took almost 4 years of rehab and pain management classes, injections only to end up with a class 2 permanate disabilty of the lower back, so i went into home/structural design sense i knew almost all the phases of construction industry, i love drawing peoples dreams into reality

[morfiend]

Based on latest code it probably should have been designed, assuming a cold roof, for 24psf flat snow load, 5psf rain on snow, round it up to 30psf...(not sure about the code 30 years ago)

30psf load with 20.5pcf density

30/20.5 = 1.46ft = 17.6 inches snow design.  Assuming no unbalanced snow, (and proper drainage) which I don't know enough about a dome structure to know if you can make that assumption.  So hell, after all safety factors, are taken into account from both snow loads and fabric loads I would think it would be able to take at least 40psf of load before failing, which would be 2 feet of snow.  Not enough info though.

  Did anyone check the snow fall that day,2 feet fell in many places,in fact in some place 3 to 5 feet fell.

   I think Grizz is about spot on because I saw a snow fall of 60 cm,for that area,which is 24 to 25 inches.

   We had 160 cm total now since the day of the colapse,which exceeds the total for all of last winter and winter doesnt start for another 6 or 7 days....  160 cm equals roughly 62 inches.


   

[Guppy35]

I'm not seeing nearly as much excitment about it here in Minnesota as on the AH BBS.  It's the Dome after all.  This happened before and it's the Vikings.  We expect something to go wrong!

The bigger drama right now is Minneapolis and St. Paul getting the roads cleared.  The Burbs did fine, but the Mpls/St.Paul have not done a very good job at clearing the roads.  As one who had to work that day, and couldn't just call in, I can tell you that driving was insane and I'm still sore from all the shoveling.  Last time it was this bad was Holloween 91.  I've got a picture of our car showing only the roof from that one