Posted on 08/01/2007 4:28:27 PM PDT by ButThreeLeftsDo
Just turned on the news. 35W bridge collapsed in the Mississippi River. Cars, trucks, semis.....
Fires burning, tanker trucks, at least one school bus, more than ten cars......
Just now breaking.......
Weird coincidence that an Internet message appeared today from Al Qaida with photo-shops of Pres. Bush and Musharraf in front of a burning White House. The message reportedly said America is in for a surprise (www.drudgereport.com)
I was trying to figure that out too. Thought it was a bridge expert, but finally realized it was Baiden, or whatever his name is.
Can’t believe he’s an expert on bridges. What a guy!
FRmail back at ya...
That was an earthquake in San Fran
Low chord elevation of 744 minus 60 feet gives a normal water elevation of 684. Piling data says that the pier in the water is near the stream bed elevation of 673. That indicates that the water is about 11 feet deep.
Wasn’t the collapse of the Tacoma Narrows bridge in 1940 blamed on resonance?
Only one tiny little problem: This bridge did not have any pillars in the water!
he knew about it because he did the autopsies on the dead from the NY bridge collapse... cause of death, cause of collapse, final report, yada yada
My husband has been a driller in NYS for over 25 years. He has many times drilled in rivers looking for bedrock. Here in NYS there most defintely are piles in our rivers.
How is that coincidental with a collapsed bridge in Minnesota?
Good to know. I just got home and am just catching up on the news.
How is that a weird coincidence? Last I heard, a bridge in Minneapolis collapsed. The White House didn't burn with Bush and Musharraf in it.
Oh okay....then he really did know what he was talking about. I was just shocked to hear him on this story.
True.
However, of course, I never said 90F temperatures could bring down bridges. I said it could be one of many factors combining to make a catastrophe.
Question: How many illegal aliens were already, and are already, sitting in those emergency wards taking space?
Question: Does this area of city area have a notable illegal alien population which, typical in other areas which do, tack the resources of emergency wards and social services?
Question: Was there construction being done on this bridge, and was this construction being done by sub-contractors who hired illegal aliens who do the work that Amercians won't do?
Just asking.
That seems like a bold statement to me.
For structural steel I would be more worried about colder temperatures and brittle fracture than higher temperatures. The yield strength for structural steel does vary for temperature, and I'd need to pull out a table to tell you how much. But the change up to 90 F will almost certainly be insignificant until you get up to temperatures about 800 F.
That depends on the environmental extremes for which the bridge was designed, doesn't it?
Check your Freep mail.
It’s a cantilever bridge. Set a concrete block on one side of a creek, another across the way, then balance a 2x10 on each block, so that they meet in the middle. If one block fails, then whole structure becomes unstable.
This bridge is comprised of two such structures side by side, at the upstream and downstream edges of the deck. The two structures are joined together by diagonal bracing between them, designed to keep a cross section of the structure square and upright.
It appears to me that the steel structure above one pier failed laterally, as if the diagonal braces between the kingposts atop both same side concrete piers failed under comprension or tension allowing the bridge deck to sway in the downstream direction before toppling over on its side.
On the far side, the steel trusses suffered shearing failure directly above the piers, dropping the main span into the river nearly intact. Then the approach span on that side lost its counterweight, began to buckle, and collapsed back towards the shore.
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