New earthquake-resilient water pipes developed

Scientists have designed and tested a new earthquake-resilient pipeline that can better protect water utility networks during natural disasters.
They ran multiple tests, including an earthquake simulation in which a 28-foot-long section of the pipe was outfitted with more than 120 monitoring instruments and buried within 80 tonnes of soil - an experiment that took over a month for the research team to prepare.
The test mimicked a fault rupture that can occur during an earthquake when global plates begin to slip past each other, causing the ground to shift and deform.
A large, hydraulically powered "split box" imposed two feet of fault rupture along a 50-degree angle, forcing the buried pipeline into a combination of compression and bending.

"The pipe was able to accommodate the two feet and didn't spring a leak," said Brad Wham, from Cornell University.
"We took the pipe to three times its current design standard, and it continued to convey water. So we consider it a successful test and very promising technology," said Wham.

While the test pipe was only eight inches in diameter, Wham said the results are scalable and could be applied to pipelines as large as 70 inches in diameter or greater.
The steel pipe, developed by JFE Holdings in Japan, uses a unique structural wave design to control buckling, allowing the pipe to bend and compress without rupturing or losing water pressure.

The wave features are installed at key locations along the pipeline to absorb large ground deformation, such as movements imposed by earthquakes and landslides or from undermining associated with scour during hurricanes and floods. The extent of its performance was unknown until it arrived at Cornell.
Following the fault rupture test, the research team spent three days carefully excavating the pipeline and will begin collecting additional data based on its deformation.