35W Bridge Collapse

A new report has come out as to why the 35W bridge in Minneapolis/St. Paul collapsed back in August of 2007.

Hassan Astaneh, a professor in University of California Berkeley's Civil and Environmental Engineering Department has reported his findings in a paper at a world conference on steel bridges in Portugal. His department has also studied the collapse of the World Trade Center for the National Science Foundation.

His paper affirms what I had suspected and that is the added weight of the equipment and the construction material put too much burden on the bridge structure. The construction company on August 1st of last year had loaded 270 tons of construction materials on the bridge.

Mr. Astaneh was hired as a consultant by a victim to study the collapse. Mr Astaneh feels the bowed gusset plate should have been detected. However, what I did not know was the biggest problem was the added weight of not only the equipment and construction material, but that an additional 2 inches of concrete to the bridge deck back in 1998.

This caused an additional 30% in weight to the bridge that the trusses had to support.

Read the complete story here:
Study: Heavy construction materials, added pavement brought down 35W bridge
by Sea Stachura, Minnesota Public Radio