My "Favorite" Structural Failure

[msquared48]

OK. I'll test the new step four.

Here is mine - an erection problem none the less, not dissimilar to the problem encountered at the Husky Stadium expansion failure in the '80's.

BRACE, BRACE, BRACE!

Mike McCann
McCann Engineering

 

[lkjh345]

Erection bracing can be a surprisingly important item.

 

[RARWOOD]

Your photo reminds me of a wood framed project that was put up about 8 years ago in Minneapolis. As I was taking my wife to work one day we drove by a four story wood framed condo project. I noticed there was no sheathing applied or any other type of bracing, so I figured it would not take much to bring the job down.

The next day when I took my wife to work, I saw that now on the job site there was just one huge pile of studs, joists and broken up roof trusses.

 

[AlmostPE]

How about the girder on c-470 in colorado? It didnt have lateral brace and had the same failure. It went down and a dodge durango hit it. the body of the car stopped (with the passangers), the bottom of the car kept going for several hundred feet. A father, a mother and a baby died instantly.

911 dispatcher didnt know what a girder was and told cdot crew to look around. They thought it was a tranportation sign or something.

 

[csd72]

msquared48,

Those beams are awful slender though.

I have seen many portal frames built where they erected the first two frames and then put the cross bracing between them. It is usually okay if you have a beam with a decent flange width.

In Australia, I never saw the first portal being braced. And in my experience the health and safety is stricter in Australia than in the US.

csd

 

[apsix]

A more comprehensive collapse.
It appears to be due to lack of top chord stability at erection time, combined with member discontinuity at the splices.
For an unusual structure such as this the designer should have specified adequate bracing during erection.

 

[apsix]

Another of the same.
(If anyone's wondering it seems that only one file can be attached per post.)

 

[msquared48]

Just to let everyone know here. I do not like any structural failure. They should not happen. That being said, the reason I refer to it as my "favorite" structural failure is that this one did NOT result in any loss of life, one or two jobs or so, but that is a story for another day.

To me, it just looks so preventable, and so stupid.

Mike McCann
McCann Engineering

 

[eliebl]

This is the type of failure that did result in loss of life about 6-8 years ago. I knew a one of the engineers who had to do a report on the failure. It is always know and understand the mistakes that are made so that we can learn from them and not repeat them. I only hope that I am never asked to look into such an unfortunate event.

EJL

 

[csd72]

apsix,

interesting pics - no cross bracing so it looks like they all rolled together.

msquared48,

The uk have a commitee aimed at learning from structural failures - I think ASCE is looking to join in on the initiative. Check out

http://www.scoss.org.uk/

csd

 

[HgTX]

The Colorado girder had what the contractor *imagined* was lateral bracing...

NTSB report here:

http://www.ntsb.gov/publictn/2006/HAB0601.pdf

Hg

Eng-Tips policies: faq731-376

 

[JAE]

HgTX - one of the final recommendations in that report:

...require the contractor or subcontractor to submit a written plan or design drawings for all construction, including temporary falsework and bracing, and to have these plans or drawings reviewed and approved by a Registered Professional Engineer..

It seems that more and more contractors are going to be hiring engineers to review construction-related shoring, bracing, erection processes, etc.