Partial Overpass Collapse Kills At Least 1 (Golden, Colorado)

FOX News ^ | May 15, 2004

[sathers]

confirmed fatalities

[tommix2]

You are correct. The top flange of the girder should have been laterally braced at several points. The flange apparently was not braced ar all allowing the girder to
twist at midspan, a common mode of failure.

[Mad_Tom_Rackham]

So the girder is meant to support its load while in the vertical orientation. But if it's upper flange is not braced against lateral movement, it can twist on its longitudinal axis and then sag (while still supported at its ends). This indeed seems to be what happened. Thanks for your insight.

Lack of supervision at the site?

[meatloaf]

I don't think it twisted. The beam still seems to be on the abutments. It fell over, then sagged because it can't support its own weight in that orientation.

Something happened with the bracing (diaphragms) on the ends to allow it to fall over. If I was the superintendent on that job, I'd be thinking up a good excuse.

[Palladin]

bump

[tommix2]

You are right. we can't tell from the picture what they had in place. It takes two girders side by side to hav diaphragms between them. WE used different methods to get temporary bracing or support while erecting them depending on the situation. One way is to assemble girders in pairs on the ground if not too heavy to lift. Another way is to use two cranes and hold one girder until the adjacent girder is braced to it. Another way is to rig temporary guys or shores if the wind is not strong. But you must calculate what you are going to do before you start. The slenderness of the bare girder is beyond the range of specifications for girders in finished atructures, and we
(the bridge company i worked for) developed our own formula to calculate this. We never had a failure.

[Tolerance Sucks Rocks]

In Dallas they have this giant overpass thing being setup at 75 and 635. I hate driving under it. They don't appear safe, and sometimes are not.

Ah, yes, the High Five interchange. I wish I lived down there so I could check it out.

[RoughDobermann]

Investigators are pictured at the scene of an accident on Interstate 70 west of Denver near Golden, Colo., on Saturday, May 15, 2004, where a steel girder fell from an overpass into morning highway traffic outside Denver crushing one car and killing three people. (AP Photo/Ed Andrieski)

Not that it's important, but the accident took place at the intersection of E-470 and I-70, which is on the EAST side of town.

[Pablo64]

Question for you: It's been many years since I worked for the highway department (in Colorado, no less) but looking at the picture where the left side of the girder is still up on the smaller pier, it seems to me that this was probably the first of the set to be placed (probably last thing on Friday before knocking off for the weekend). Typically, the girder would have been set on its pier bolts and the nuts tightened down. Some sort of lateral bracing would definately have been needed (as you pointed out), but do you think that perhaps there was a failure of the anchor bolts, or concrete or such, that allowed it to tip? Or would the lack of lateral bracing (combined with maybe some strong winds) be enough to start some movement back and forth and thereby work loose or damage the bolts?

I just can't imagine somebody not securing that beam properly considering how careful they usually are in all stages of handling them. My understanding is that those are custom made for each placement and any excess twisting or such while placing them can render them useless by causing the holes to not line up with the preset anchor bolts. What do you think?

[US_MilitaryRules]

I beams work 1 way. When they are taller verticaly. This 1 appears to have rolled sideways and bent under its own weight. Looks like it wasn't secured verticaly very well and an earthqake/road vibrations via trucks, might have tipped it.

[cubreporter]

I hated that 6th Avenue exit also. You described it correctly. Haven't been up that direction in a long time. Very sad about the family. Tragic...just tragic.

[cubreporter]

We never know do we? Thank God for your son's safety. Prayers for the victims and families of the tragedy.

[RightWhale]

It was an SUV. It is the responsibility of anyone who notices such a thing as a girder about to fall to inform someone who seems to be at least potentially awake at the construction site.

[Tall_Texan]

Yes, I saw that. Too bad for the family.

[ThePythonicCow]

Ouch - that's gotta hurt ...

[tommix2]

Or would the lack of lateral bracing (combined with maybe some strong winds) be enough to start some movement back and forth and thereby work loose or damage the bolts? Probably this what happened. I just can't imagine somebody not securing that beam properly considering how careful they usually are in all stages of handling them This what I meant by cutting corners. Obviously, they did not secure it properly or it wouldnot have collapsed, and now an innocent person is dead.

[Vince Ferrer]

Investigators are pictured at the scene of an accident on Interstate 70 west of Denver near Golden, Colo., on Not that it's important, but the accident took place at the intersection of E-470 and I-70, which is on the EAST side of town.

If it was in Golden, I think it would be the C-470 overpass.

[nvatexan]

Here is the website for the "High Five" project.

http://dallashighfive.org/

[robjna]

this is truly a freak accident, the timing of being exactly underneath at the time of impact is scary, one second either way and it is a partial or no -impact situation. I feel for the victims as it could anyone of us driving under the constant construction of overpasses on our freeways

[Redbob]

In marked contrast to the construction superintendents and design engineers for example on the Kansas City Hyatt Regency skywalk project?
Plenty of carelessness and poor jdugement to go around there.