September 18, 2008

BIRMINGHAM, Ala. - UAB Assistant Professor of Engineering Chris Waldron, Ph.D., is in his first semester at the university after working for the firm behind the design and construction of the new Minnesota Interstate 35W Bridge that replaces the previous structure that collapsed in the summer of 2007, killing 13 people.

The engineering professor, whose area of interest is the life cycle and durability of bridges, said that the new Minnesota Bridge uses state of the art technology to prevent a future collapse over the Mississippi River.

"The new bridge is structurally redundant, and so if one component of the bridge fails, it is less likely that the structure will collapse the way the old 35W Bridge did.  The old bridge was not structurally redundant, so when the plates that held the bridge components together failed as the experts speculate happened, the entire structure came down," Waldron said.

Waldron described the new bridge's post-tensioned concrete design as critical in its safety.

"The bridge has steel strands that run through the concrete and are stressed to put force onto the structure, compressing the concrete to keep it from cracking," Waldron said.