‘Smart’ pipes call for help

UC IRVINE (US)—A CD-sized sensor could help keep the water running during earthquakes and other disasters by sounding an alert when pipes crack or break. The sensors are being used to develop a wide-scale pipe monitoring system in California.

Engineers at the University of California at Irvine developed the sensors and are working to outfit the local water system in an effort to speed repair time when pipes fail.

“When an earthquake occurs and infrastructure systems fail, continued service of the water network is most critical,” says Masanobu Shinozuka, chair of civil and environmental engineering at the Henry Samueli School of Engineering at UC-Irvine and the lead investigator on the project. “Before anything happens, I’d like to have a pipe monitoring system in place to let us know when and where damage occurs. It could minimize misery and save lives.”

Shinozuka and Pai Chou, associate professor of electrical engineering and computer science, designed the devices to attach to the surface of pressurized drinking water and nonpressurized wastewater pipes to detect vibration and sound changes that could indicate pipe problems. Through antennae, the sensors relay information wirelessly over long distances to a central location for recording, processing, and diagnostic analysis.

Initially, the sensor network will cover about one square mile of the local water system, but eventually the scientists say it could encompass more than 10 square miles—the largest system of its kind to date.

The research team is now designing a network that functions underground as well as over a larger area. The main hurdles, Shinozuka says, are powering the sensors (batteries and solar energy are not strong enough), making them more cost-effective and robust in tough environments, and achieving long-range wireless communication efficiently and accurately.

The sensors will complement an existing monitoring system which is “too sparsely placed for identifying damage with the kind of precision we desire when a large earthquake or other natural hazard affects many locations,” Shinozuka adds.

Such a system could significantly reduce the amount of water lost each year to water main breaks. In the United States, water main breaks number about 240,000 a year, wasting up to six billion gallons of drinking water every day.

“An isolated malfunction is far different from a situation in which pipes break all over the place,” he says. “Our next-generation system will inform us as soon as possible when and where damage occurs and to what extent so we can better mitigate the consequences.”

The work is funded in part by the National Institute of Standards and Technology.

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