On the SDPB Radio Midday Program today, Paul Guggenheim interviewed "Connie" of the Minnesota Highway Department on the rapid building of the replacement bridge in Minneapolis.
Well, that was what I thought until I started searching for somebody in the department with that name. I finally found the story from SDSU on the lecture to engineers there.
SDSU Announces Lecture with alumnus Khani Sahebjam
Every now and then, radio announcers may need to literally spell some names. TV shows can plaster names on the screen in text....anyway.....
Interesting program.
Getting a major collapsed bridge rebuilt in about a year is a major accomplishment. The November-December issue of American Scientist has a good story on the engineering and procedures tied to bridge inspections, etc. written by Henry Petroski who regularly contributes articles related to engineering. The story is on pages 444-448 of the
November-December 2009 issue. The author mentions the Minnesota Transportation Dept., but gives no credit to anybody there for providing information.
If you are a member of the society or a subscriber to the magazine, you
can read the story at the link. I have just been buying the magazine on the news stand so can't actually get the story at the site.
American Scientist (restricted link) Bridge Story
However you do read it, it is an interesting story and the photos are good. One fact that is interesting:
"In the 40 years that the old bridge stood, well over a billion people may have crossed it"
The bridge had carried 140,000 vehicles per day with perhaps 200,000 people per day.
Inspection of the wreckage suggested that some gusset plates failed probably because a contractor had tons of equipment and gravel on one end of the bridge and the asymmetrical loading was just too much overload coupled with the high volume of traffic. Even though the bridge had survived for 40 years, it was under designed.
The replacment bridge was made in sections and glued together with epoxy and held together with internal stretched cables. Some information is available
here:
Concrete Products Awards

The photo above is from the Minnesota Dept of Transportation. Click on it for a larger version. A good black and white photo of a beautiful new bridge and associated sculptures are in the American Scientist story. Google searches for " St. Anthony Bridge I-35w" will turn up a lot more information
And as a kind of sidenote, the American Scientist story had a word I had never seen before. "Charrette" which in the story referred to a planning meeting in the Mn Dept of Trans. I guess the term was exactly appropriate if the definition below is correct.
"Charrette"definition
So, Silo Tech puts out product more important than football teams.
*** Stay tuned even if you can go anywhere from Dakota Today -- Doug Wiken
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