Talcoma Narrows "Galloping Gertie"
type: suspension bridge, gravity anchored, steel girders suspended spancompleted: 1940
collapsed: 1940
toll: 1 dog
cause: aeroelastic flutter; steel girders
see: http://video.google.ca/videosearch?hl=en&q=bridge%20collapse&um=1&ie=UTF-8&sa=N&tab=wv#
I-35 bridge in Minnosota spanning the Mississippi Rivertype: steel truss arch bridge
completed: 1967
collapsed: 2007
toll: 13 killed, 145 injured
cause: lack of redundancy in main truss system; fatigue cracking in cross girders
see: http://video.google.ca/videosearch?hl=en&q=bridge%20collapse&um=1&ie=UTF-8&sa=N&tab=wvhl=en&q=bridge%20collapse&um=1&ie=UTF-8&sa=N&tab=wv#
Laval (Montreal), Quebec
type: concrete cantilevered prestressed box girder
completed: 1970
completed: 1970
collapsed: 2006
toll: 5
cause: multifactoral; not enough steel reinforcement rods supporting the corbel joint in the abutment
The causes for the I-35 collapse are not correct. The primary cause was a design error leading to one of the gusset plates to be significantly undersized. The secondary cause was the unfortunate placement of construction materials an equipment directly above the weak joint during resurfacing work.
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