The epoxy supplier knew full well that his brand wasnt good for the long haul and assumed the construction bosses knew that too — but they did not know that.
So, the bottom line is that the I-35W bridge “apparently lacked the kind of redundancy planning that is the norm today,” Teschler asserts. And since the I-35W bridge was designed in the 1960s it went online prior to the ASCE began noticing the “increased frequency of structural failures” — an unfortunate bit of timing indeed.
The new I-35W bridge that spans the Mississippi River and provides a reliable route into and out of the Minneapolis area has been fitted with “a complex array of more than 300 sensors” which will hopefully act as a “structural health monitoring” system (Murray, 2008).
Typically, Murray writes in Design News, sensors are applied to older structures; but in this case, taking extra care to assure the safety of the bridge is pivotal to public faith in engineering. It is too bad sensors werent installed on the original bridge construction; lives may well have been saved.
Ichniowski, Tom. (2008). NTSB Cites Gussets and Loads in Collapse. ENR: Engineering News-
Record, 261(16), 60-61.
McNichol, Dan. (2007). A Troubled Bridge Over Water. Roads & Bridges, Retrieved April 15,
2009, from http://www.roadsbridges.com.
Murray, Charles J. (2008). Sensors Deliver Real-Time Info on New Minnesota Bridge.
Design News, Retrieved April 16, 2009, from http://www.designnews.com..