ENR: Can they warn of possible failure, and if so, how?

Nader: Yes they can provide a warning. In the case of the Bay Bridge the sensors are connected to the bridge monitoring system.

J. Garrett, dean of the engineering department at Carnegie Mellon University, responded to a request for comment by noting that CMU's Smart Infrastructure Institute has been studying implementation of sensor technologies that may be helpful in this case.

"One technology they might consider for monitoring portions of the bridge are piezoelectric actuators that generate and receive ultrasonic waves," Garrett says. "A group of faculty and students in Carnegie Mellon University’s Smart Infrastructure Institute (SII) is exploring the use of these sensors and advanced signal processing and machine learning techniques for determining the existence and extent of different types of damage in metal pipes. This technology has also been explored for application to structural steel connections and rail stock."

Garrett says he also has circulated the request for comment among experts in the field and encouraged join the discussion.