35W Freeway Bridge Collapse

[frigilux]

I got such a kick from this article; The teenage 'bridge hero' who got the kids off that bus declined an offer to have his picture taken with George Bush when Dub visited the site a few days ago.

And Dunwoody Tech College is going to pay his tuition.

There is hope for the world.

http://www.nytimes.com/2007/08/07/u...b2&ei=5124&partner=permalink&exprod=permalink

 

[buffster]

The teenage 'bridge hero'

Humility is a virtue.

It's nice to see that there are still a few humble people out there not clamoring to be media hogs or opportunists, benefiting from the misfortunes of others.

 

[goprog]

And in contrast, the police have arrested a couple people for
claiming to be bridge experts so they could sell something.

The question is whether or not he declined to have his picture
taken with Bush out of humility or principle or he just likes
fishing.

Phelps and Coulter, brother and sister? Evil spawn of Satan?

 

[retroguy]

goprog....

I believe you may be correct about Phelps and Coulter. Satan is the Father of hatred.

 

[sudsmaster]

Latest on bridge engineering

Recent news wire stories state that bridge inspectors have zeroed in on various gusset plates that are used to reinforce the joints between different steel girders in the bridge substructure.

Several problems were mentioned: the plates may have been too thin; they used rivets instead of bolts to hole the plates to the girders, it takes more rivets than bolts to hold a plate in place, hence more holes in the plate and hence a weaker plate, and rivets can work loose in time; when cracks were found they were fixed by welding - welding can result in a more brittle steel structure unless the heat affected zone is carefully managed (difficult sometimes to do out-of-doors); the bridge design may have had flaws such as the too-thin gusset plates and miscalculation of the loads the bridge would be subjected to.

Another factor may have been the extra weight of additional materials and vehicles, including a cement truck, parked on the bridge for the deck repair work.

 

[goprog]

I can't quite go along with the "extra weight" on the bridge.
During rush hour, that bridge is pretty much bumper-to-bumper
across 4 lanes of traffic (well, if the traffic is moving there
MIGHT be a car length or two between vehicles). With traffic
down to one lane each way, there would have to be a whole lot
of construction equipment on the bridge to make a difference -
I would think. But there could have been.

 

[sudsmaster]

Yeah, I was a bit doubtful about the weight thing as well, but... a fully loaded cement truck, plus other building materials, plus the jack hammering... it all could have been the proverbial straw... esp. if the jack hammering through the deck severed what little was holding the bridge together at that point.

Uncorroborated stories are that construction workers noticed that the bridge was swaying side to side in an unusual manner as they loaded material and equipment onto the bridge a day or two before the collapse.

 

[goprog]

Aerial picture "moments" before the collapse

shows very little (IMO) equipment and traffic on the bridge.
(Was on the local news tonight - expect it was seen elsewhere.)

 

[goprog]

A ninth body has been recovered. Not unexpected, but one of
the local news websites says "The Red Cross needs your help
with the I-35W Bridge Collapse".

Sorry, I don't think they are related and it ticks me off they
are spinning this. It may be that blood or plasma is needed in
general, but the bridge collapse (IMO) has nothing to do with
that need or anything even approaching a minor portion of that
need. Am I wrong? (Yeah, who knows, maybe it's just rhetorical
in nature, but well-regarded institutions should not be mimicing
our politicians, media, and corporations in trying to take
advantage of any news item. At least they didn't declare a
need for blood when Paris Hilton went to jail I suppose...)

 

[sudsmaster]

As I understand it, the Red Cross does a lot more than just collect and distribute blood. In various natural disasters, it mobilizes its volunteers to help displaced people find shelter and other necessities of life. Obviously the bridge disaster didn't displace many, if any, people. But it's possible that there is a need for a rare blood type amongst the critically injured still in hospital?

It's also possible that the local news website got its information wrong.

 

[goprog]

Egad. The "Secretary of Transportation" is on "The News Hour".
She made a comment about bridge "construction" materials, etc,
being on the bridge and construction companies should calculate
bearing loads. While that may be true, the aerial picture of
the bridge before the collapse showed significantly less "stuff"
on the bridge than normal rush hour traffic would be. Looks
like another attempt to divert attention from the real problem.
(IMO) She also has lots of excuses why the gas tax should not
be increased.

 

[sudsmaster]

Goprog, do you remember the 50th Anniversary of the Golden Gate Bridge? They closed the bridge to traffic and let people walk the entire width and length of the bridge. Photos showed the bridge with a decided slump in the middle of the suspension span... from the weight of all those human bodies, which turned out to be far more than the weight of bumper-bumper traffic.

Similarly, it's possible that heavy construction materials stacked on the 35w bridge could be equal to or greater than that of bumper-bumper car traffic. It might even be worse if the materials were concentrated in one area, an unbalanced type of load.

Let's let the forensic engineers do their job and see just what combination of factors caused this collapse.