USC College of Engineering researchers are part of a national team that is working to develop technologies that will be able to examine the structural integrity of bridges. The research is being funded over five years by a $14 million dollar federal grant. USC’s portion of the grant is $4 million dollars. The other funds will go to the University of Miami, Virginia Tech, and the Physical Acoustics Corporation of Princeton, New Jersey. An important part of the project is the development of wireless sensors that can detect flaws in bridge. USC Engineering professor Dr. Paul Ziehl (zeal) says each institution has a specific role in the research program.”Te University of Miami and ourselves are heavily involved in gathering the information, making sense of the information and what is generally called ” bridge prognostics.” In other words, determining the health of the bridge at this time and projecting that into the future.”
Ziehl says “This study addresses a critical need in the nation’s infrastructure because many of our bridges were built 50 years ago, and many of these structures have a life expectancy of about 50 years.”
Ziehl says the sensors developed from the research must be able to pick up what is known as “surface waves” from the structure that is being monitored. ” The key aspect is that as damage grows in a structure, that causes surface waves to propagate that aren’t audible and aren’t visible but you can pick them up a good distance from where the damage occurs with these piezo-electric crystals. We are also developing new sensoring technologies with Dr. (Victor) Giurgiutiu (jurjutzu)) primarily in the Mechanical Engineering Department, where we pass waves through the material and detect damage from some of the sensors.”
Ziehl says the research focuses on concrete and steel bridges.
Ziehl says it is hoped that within the research period of five years, a cost efficient, reliable, round the clock system for monitoring the structural integrity of bridges will be developed. The idea of bringing all the different data inputs together coming into a system that has some level of intelligence as far as interpreting the data and having it be a self-powered system with wireless transmission for continuous monitoring is a product that is not available right now.”
Ziehl says when the system is developed for marketing, older structures, in his opinion, should be monitored first. “We have some structures that are clearly aging, degradation is taking place. My gut feel would be that the best place to install them would be on existing structures that have critical areas where we know we have areas of high stress or accelerated corrosion.”
The Federal Highway Administration estimates that more than 70,000 bridges in the United States are structurally deficient.