Bridge Health Monitoring: Reality

"When heavy trucks rumble across the Burlington-Bristol Bridge, new sensors detect the stresses they put on the 2,300-foot span and instantly transmit the information to computers in Philadelphia.
Drexel and its partner, the Burlington County Bridge Commission, plan to use the system continuously to help the agency better allocate its resources for bridge maintenance.
In Minnesota, for example, engineers are analyzing data from hundreds of sensors on the new Interstate 35 bridge erected last year in Minneapolis to replace the span that collapsed in August 2007, killing 13 people. Yet one challenge in monitoring long-standing bridges is understanding stresses that are inherent in the structure, according to French. She pointed out that one cause of the I-35 collapse was that its gusset plates were too thin - a design error committed a half-century ago and not necessarily detectable if sensors had been attached.
Others are exploring wireless sensors, which were used in a pilot project on the Golden Gate Bridge."




http://www.philly.com/inquirer/local/20091116_Bridge_sensors_send_stress_data_to_Drexel_researchers.html