Bridge 9430 Theory
With thousands of bridges that have been built in the country and with the long history of design, construction and inspection of these structures it is extraordinary that this critical structure has been allowed to deteriorate to point of complete failure causing such a dramatic impact in a major metropolitan area. it is reasonable to ask hard questions about why this happened.It is quite likely that political factors have interfered with the process of maintaining the infrastructure in the state of Minnesota.
Although all the facts have not been compiled, based on some of the things i have researched and the reports that have been made so far, I have come up with a possible scenario that might explain why this disaster happened.
I was fortunate to make my online inquiries early before the flood of online material concerning this event had buried a lot of the existing information available on the bridge and its history.
1960s : The MNDOT builds a relatively inexpensive bridge across the Mississippi river in order to complete I-35W within an aggressive time schedule.
Late 1990s: Bridge 9340 is showing signs of significant wear and is being patched and reinforced frequently. The structure is rapidly succumbing to overbearing traffic load and age and needs to be replaced.
2000: With highway funding in short supply and roads needing increasing and expensive maintenance the MN DOT is desperately looking for ways to save money on maintenance. The state awards grants to U of M researchers to conduct a hi-tech research program designed to convince legislators that many aging bridges may be replaced at a later time than determined by standard metrics. It is thought that a report presented by respected civil engineering academics using state-of-the-art computer technology and some equations would be a convincing way to defer spending of many millions of dollars in funds on repair and replacement of existing structures. The 9340 bridge was a good candidate because of its financial liability and it close proximity to the research facility.
2002: After a year or so of tests on the 9340 bridge, U of M researchers publish a report that suggests that the bridge does not need to be replaced for at least 15 years and should be inspected more often. It also states that the bridge is unlikely to collapse despite flaws in the structure and discounts any evidence assembled my traditional inspection criteria. The report is practically calls the established procedures for determining bridge replacement obsolete and advocates applying the process to many other bridges throughout the state potentially saving hundreds of millions of dollars in funding that would otherwise go toward the timely replacement of potentially dangerous bridges in Minnesota. Replacement of the 9340 bridge is put on the back burner as the now invalidated inspections continue. Suggested repairs are delayed. The researchers stick feathers in their hats.
2007: Bridge 9340 experiences total structural failure and creates a major disaster for the Twin Cities metropolitan area.
Questions remain:
Who came up with the idea to perform research on this structure?
Who approved it?
Who made the decision to accept researchers advice over the established procedures of the DOT inspections department?
Labels: 35-W, bridge 9340, minneapolis, mississippi
posted by Rev. Barking Nonsequitur | 3:52 PM
10 Comments:
I think you've got it right. The 2001 report completed by the UofM also found that fatigue cracks were theoretically not possible because the observed stress levels were not high enough to cause fatigue. This is curious given that the UofM experts were called in because inspections had already found cracks.
Even despite this the 2001 report recommended reinforcing the bridge or increase the frequency of inspections. DOT chose to increase inspections.
If you look at the inspection reports completed for 2005 and 2006 you will see that they are nearly identical. Both reports include the exact same photographs (not different photos of the same areas, the same photos). If the purpose of inspection is to monitor critical areas and examine the structure for crack growth why are new photos not taken every year.
The bridge collapse appears to be the result of faulty process that has been years in the making.
I have not seen the '06 report. As I recall the '02 report had pictures that showed the critical structures that needed be inspected so maybe they were just for identification instead of showing how bad the condition of them was.
I recall reading that although there was fatigue and cracks, the structure was unlikely to collapse.
That seemed like a flimsy rationalization on the part of the researchers - and of course they were completely wrong and probably knew better.
What is so stupid here is the NTSB defending the merits of the study which was obviously flawed and perhaps fraudulent and they are trying to use the same process to perform forensics on the collapse.
This may be the subject of my next blog piece.
God bless Ronald McReagan and all of the other Republican Party assholes that have followed, for thier unceasing efforts in thwarting the EPA and other watchdog agencies. Agencies that would only waste money protecting the unwashed masses. It's so much more efficient to start wars and syphon money into the pockets of the Military Industrial Complex than to support National infrastructure. Besides, nobody wants those construction jobs, so they would probably fall to "undocumented" immigrants, right?
Bitter? Disgusted? Nah!
Q: How does a Republican say, "Fuck you"?
A: "Needs more research. Go back and do it again."
Since (theoretically) you can't sue the governmet, it is cheaper to let the structure fall down, let private insurance pay out, and then build a new bridge, than it is to condemn and purchase property, build a parallel bridge, and demolish the old structure. This is the same logic that kept Ford from installing $6 bumper guards on the Pinto, and prevented Chevy from discontinuing side-saddle gas tanks, so it must be logical. Of course, you have to make a great show of ritualized sadness to make it look good.
Breaker - those are all great observations. Funny how they keep limiting the damages companies can pay to litigants. You are right - they just give out platitudes and then sweep everything under the rug again.
If I see one more friggin' prayer/bawl session I'm going to puke.
Grown men and women on their knees - and now, a mine collapse in Utah - and people performing gestures of acquired helplessness while the rescuers are bumbling about, like those who could not rescue the sailors on the Kursk. Just disgusting. I hope we didn't turn away foreign help this time, too, as we did during Katrina.
We have processes in place to prevent such occurrences, but I'm afraid that the American people are attributing more and more human-made problems to God.
The identical photographs cited by Anonymous sounds like the fake photos right out of The China Syndrome. Different disaster, fictionalized one - but the same problem: inspections not done properly, or faked, because of money. So get on your knees, America.
My new motto: Only prey pray.
Rev. Barky, I just thought of something - what's your take on the condition of the bridge at Ford Parkway?
I take that bridge twice a night between grad school and the 46th Street Light Rail Station.
Just suddenly got creeped thinking about it.
It says they just spent $18M working on it the last couple of years.
Intercity/Ford Bridge - http://en.wikipedia.org/wiki/Intercity_Bridge
The country may be way behind in fixing its bridges, but I think the chances of anyone being caught on a collapsing bridge is much less likely than being hit by lighting.
Actually, I read one of the worst ones on the area is the Lafayette bridge in Saint Paul. I'd stay way from that one in a thunderstorm.
Okay, thanks. ;-)
Post a Comment
<< Home