Bridge Collapse

[yesman065]

Originally Posted by Urbane Guerrilla

Now I'm calling BS on you.

Shouldn't the emphasis be on "you"? As in: Now I'm calling BS on you. Seems to read better - just a thought.

Speaking of the Bridge Collapse - did anyone else get a letter from their local rep with the new budget on it? Mine had a whole lotta cash specifically designated for this. I thought the timing was rather convenient.

[Urbane Guerrilla]

I mulled over that style of doing it -- but decided against using too much italic font. It may express emphasis well in voice, but in text it's easier to overdo. It was one pronoun or the other, but both becomes just that bit much. I picked one; the other would have worked too.

Hey, politicos budgeting money will react swiftly and strongly to a very public disaster. It's particularly obvious in a nice transparent democracy.

[barefoot serpent]

I'm calling pigeon guano on the whole lot of ya!

Inspectors began documenting the buildup of pigeon dung on the span near downtown Minneapolis two decades ago. Experts say the corrosive guano deposited all over the Interstate 35W span's framework helped the steel beams rust faster.

[yesman065]

"no shit?" I mean yeah - shit!

[xoxoxoBruce]

They have finished with the bird shit and are moving to the deicing system next. They have a long way to go yet. A waste of time and money, really... everybody knows Bush did it.

[tw]

Originally Posted by xoxoxoBruce

They have finished with the bird shit and are moving to the deicing system next.

I am still waiting for analysis that includes significant terms such as 'fatigue'. Also troubling is that redundancy did not exist on this bridge. Redundancy is even found in Roebling 1880 bridge - the Brooklyn Bridge.

Rusting is a common problem in so many bridges such as NY's Williamsburg Bridge that was not painted for 30 years. It took a falling structural member to finally get maintenance restarted.

One need only visit Philadelphia to view Interstate 95 some 40 feet above those neighborhoods. Rust is rampant everywhere. Is that 6 or 8 lanes highway ready for collapse?

The Golden Gate Bridge gets repainted constantly. A painting crew is constantly repainting that bridge. With landfall on Marin County, then the painting starts all over again in San Francisco. How many other bridges get that kind of maintenance?

But rust alone typically does not cause fatigue; would be unacceptable long before rust could create fatigue. However this MN bridge had no redundancy. This then begs the question why routine electronic monitoring is not installed on bridges without redundancy.

Questions that we should expect an engineering analysis to answer.

[xoxoxoBruce]

Originally Posted by tw

One need only visit Philadelphia to view Interstate 95 some 40 feet above those neighborhoods. Rust is rampant everywhere. Is that 6 or 8 lanes highway ready for collapse?

I've been hearing "experts" grumbling, for several years, that the whole elevated section of I-95 through Philly should be completely rebuilt. What a clusterfuck that would be.

[tw]

Originally Posted by xoxoxoBruce

I've been hearing "experts" grumbling, for several years, that the whole elevated section of I-95 through Philly should be completely rebuilt.

A point made (if I remember) in The Economist. There is no political reward for doing maintenance. Political reward is in building something new. Mayor Lindsay in NY had two choices. Maintain the bridges (ie Williamsburg) or rebuild Yankee Stadium - corporate welfare for the Yankees. Lindsay rebuilt Yankee Stadium.

Don't paint I-95 and don't do any maintenance on Veteran's Stadium - and the city will get everyone in PA to rebuild them. Phillies were given a new stadium for free paid for by all PA taxpayers. Clearly that was cheaper than standard maintenance.

[xoxoxoBruce]

Monday morning quarterbacking on the net.

At http://taxa.epi.umn.edu/bridge/ an Epidemiologist (it's about diseases, nothing to do with bridges or engineering) weighs in with his theory.

He's blaming the construction/repair work.... with 8 x 10 glossies and a paragraph on the back.

[warch]

Trying to share some pics of one of the sorting sites. Lots of scrap has gone through the site- metal, rebar and concrete. Barges bring it down, it is sorted and categorized then barged or trucked to another place for study.

not sure how to post a pic. If youre interested. you can send me a message and give me some posting tips...I give up!

[piercehawkeye45]

Assuming the photo is saved to your computer:

1. Go to http://imageshack.us/
2. Browse the photo you want to host and click "host it"
3. Copy the direct link address (bottom)
4. Click on the "instert image button
5. paste url

[warch]

[IMG][/IMG]

I'll try this one...thanks! They have actually moved a bit out. Last week there was quite a pile of broken rebar chunks.

[warch]

try again...here is a sorted area of metal...

[tw]

I assume that construction was to repair the surface of what is called the expansion joint. Using the maps and pictures, that expansion joint is located directly above support rollers for the south end. A bridge must expand and contract. Those rollers permit that change. But I understand one of the south support rollers had seized and was repaired.

Well that expansion joint would be directly above those rollers. I doubt construction on that expansion joint caused a failure. However they may have been fixing a symptom. The reasons for that expansion joint repair may have been due to fatigue orginally created by that seized south support roller.

Obviously this is all speculation. Photos only provide dots that the engineer's analysis must connect with lines to explain the entire failure.

I had heard expansion joints were repaired. That picture may be that expansion joint. Not described is why repair is necessary. Was the defective expansion joint due to a growing bridge fatigue? Curiously, that expansion joint is directly over what I am guessing is the support roller that seized.

[xoxoxoBruce]

Here's a picture I found on Wunderground that shows the cleanup progress.