Here is my website and pics. I am determined to eliminate these tolls. Here is a sorry point in the bridge...
Posted on 08/08/2007 7:59:09 PM PDT by neverdem
MINNEAPOLIS, Aug. 8 — Investigators have found what may be a design flaw in the bridge that collapsed here a week ago, in the steel parts that connect girders, raising safety concerns for other bridges around the country, federal officials said on Wednesday.
The Federal Highway Administration swiftly responded by urging all states to take extra care with how much weight they place on bridges of any design when sending construction crews to work on them. Crews were doing work on the deck of the Interstate 35W bridge here when it gave way, hurling rush-hour traffic into the Mississippi River and killing at least five people.
The National Transportation Safety Board’s investigation is months from completion, and officials in Washington said they were still working to confirm the design flaw in the so-called gusset plates and what, if any, role they had in the collapse.
Still, in making public their suspicion about a flaw, the investigators were signaling they considered it a potentially crucial discovery and also a safety concern for other bridges. Gusset plates are used in the construction of many bridges, not just those with a similar design to the one here.
“Given the questions being raised by the N.T.S.B., it is vital that states remain mindful of the extra weight construction projects place on bridges,” Secretary of Transportation Mary E. Peters said in a statement issued late Wednesday.
Since the collapse, the concern among investigators has focused on “fracture critical” bridges, which can collapse if even a single part fails. But neither the safety board nor the federal Department of Transportation on Wednesday singled out any particular design of bridge in raising its new concerns about gusset plates and the weight of construction equipment.
Concerns about the plates emerged not from the waters of the Mississippi River...
(Excerpt) Read more at nytimes.com ...
I heard it is I-280 now.
You aren’t far off afield. Many times, a bridge collapse or the failure of a structure has more than one cause. Sometimes, each cause in itself is not enough to make a structure fail, but the combination is what does the trick.
It will be most interesting to see what the examination finds. This will be an engineering case study for many years into the future, and many engineers will have this in their course of study.
Was, but isn't for long...
It's definitely not an Interstate, however they blocked the intersections and locked the signal lights on green to help with the traffic flow.
Just had to laugh out loud today when they revealed the new plans for a bridge. 5 lanes of traffic with space down the middle for light rail.
I understand that there are actually four videos from the Army Corp of Engineers, but I have only seen one, and I think that is the one you refer to. It shows the southern end of the bridge. It would be interesting to see the full view of what happened from a more distant vantage point.
Gravity is hard taskmaster, as are unbalanced forces. Both show themselves in the video, when they are rarely “seen” in real life, but ever present. Every bridge, every building, every structure is resisting forces all the time, yet we see them as static creations. They expand and contract, resist forces until they are demolished, or until the unthinkable happens, and they fail.
Where do you come up with a weight of 80,000 lbs. for an 18-wheeler? Back in my college days, I worked as a Teamster and loading 40,000 on a trailer was a heavy load. With the weight of the tractor, your pushing maybe 55-60,000. Am I missing something here?
Explain to me what you think they were doing dumping rock onto the bridge?
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Well,,,Maybe they wuz buildin’ a “gravel-road-bridge”?...;0)
Are you sure you don’t have north & south reversed? (Hint: look at the sun angle and shadows...)
80,000 lbs is standard maximum load and all that is allowed by MN law on the roads. These trucks were filed with rock so no problem making the weight within capacity.
There have been differing views on what is where.
From what I have seen, I think I have it right. But I have even seen the ends of the bridge referred to as “east” and “west”.
That’s why I describe the piers. The pier at the water’s edge, that ended up out of alignment, is what I call “south”. The north pier is what I refer to as the one with the pier tops missing. It is clearly the landlocked one.
One of the madening things about the news coverage was that with all of the aerial photos shown there were no north arrows for orientation.
Here is my website and pics. I am determined to eliminate these tolls. Here is a sorry point in the bridge...
Thanks for the feedback.
Yep. But mostly, this tragedy is a result of BAD PLANNING. Construction during rush hour, poor load division (traffic and construction materials), vibration effects.
IIRC, two lanes were closed. I wouldn't be surprised if the collapse was multifactorial, with the loading on the bridge just one of the factors. I like the NY Times' coverage for these disaster stories because the articles usually have decent graphics. I ignore the political spin when it's present.
just noticed there are some new (to me) videos at one of the local tv station. Interesting.
they are at kmsp.com sorry, dont know how to link
From the video I saw, it appeared that both ends of the span collapsed at the same time - no slow motion - and immediate.
80,000 is the legal limit except for MI where it is 160,000#. 80,000 is 40 tons (last night I got 4 when dividing 80 by 2), so 100 tons is 2.5 trucks at thee legal limit.
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