July brought a reminder of the perennial great earthquake threat, with a series of major tremors in California.
Among the many risks that earthquakes unfold, one has been reduced by engineers at Alabama-based AMERICAN Cast Iron Pipe Co. (ACIPCO) — the disruption in water supply.
AMERICAN — one of Alabama’s largest manufacturers, founded in Birmingham in 1905 — makes ductile iron pipe, spiral-welded steel pipe, fire hydrants and valves for the waterworks industry and high-frequency-welded steel pipe for the oil and natural gas industries.
AMERICAN Cast Iron Pipe Co. introduced its Earthquake Joint System in 2015. In 2016, a study by Cornell University found the system can withstand ground ruptures in excess of those experienced during some of the world’s most catastrophic earthquakes.
The system, for use with AMERICAN ductile iron pipe, valves and hydrants, was tested at the Geotechnical Lifelines Large-Scale Testing Facility, a research facility of Cornell’s School of Civil and Environmental Engineering in Ithaca, New York. Test results cite AMERICAN’s system was able to axially extend at least 5.4 inches per joint, enough to resist more than 99 percent of earthquake-induced ground strains measured following four major earthquakes during the Canterbury Earthquake Sequence in Christchurch, New Zealand.
To put this into perspective, according to the report, the levels of earthquake-induced ground deformation measured in Christchurch exceed those measured in the 1989 Loma Preita, California, and 1994 Northridge, California, earthquakes, and are comparable to those documented following the 1906 San Francisco earthquake.
“Caused by failed gas and electrical lines, fires typically follow seismic events. Unfortunately, the water lines that support the fire protection systems have typically failed also,” said Derek Scott, marketing and technical manager with AMERICAN Flow Control, the valve and hydrant division of AMERICAN Cast Iron Pipe Co. “Water is the first defense against fires. AMERICAN’s Earthquake Joint System is a key component to keeping the hydrant lead intact, and therefore helping to ensure firefighters have the water they need to fight fires following an earthquake.”
A fast motion video was taken during the Cornell University study, showing the disruption of the ground’s surface under the simulated conditions of an earthquake. AMERICAN’s Earthquake Joint System is buried underneath. A second video shows the test crew unearthing AMERICAN’s Earthquake Joint System to find it passed the test, withstanding the ground forces of the simulated earthquake.