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ambience: sounds of earthquake,
We’re listening to a time lapse recording of an earthquake. Well, sometimes during a severe earthquake, loose rock and soil beneath the surface can begin to act like a liquid – causing waves to move across solid ground the same way they travel across a lake or pond. It’s a dangerous occurrence called ‘soil liquefaction.’ I’m Jim Metzner and this is the Pulse of the Planet presented by DuPont. Tom O’Rourke is a Professor of Civil and Environmental Engineering at Cornell University.
“The shaking from the earthquake generates water pressures within the soil that turn it, literally, into a liquid or a viscous fluid .For example, during the most recent Kobe earthquake of 1995, soil liquefaction generated ground movements of one to four meters.”
That ‘up and down’ movement can cause underground pipelines to rupture – releasing chemicals or natural gas. O’ Rourke and his team want to build new pipelines which can resist the stress of soil liquefaction, so they’re recreating ground ruptures here, in their laboratory.
ambience: earthquake test
“We simulate earthquakes to test pipelines by developing the type of ground rupture that the pipelines would be subjected to during the actual earthquake. To do this, we create a large holding box with many tons of sand that simulates the boundaries of a landslide, a liquefaction area, or a surface rupture caused by faulting.”
We’ll hear more about how earthquakes affect underground structures like pipelines in an future programs. Please visit our website at pulseplanet.com. Pulse of the Planet is presented with support provided by the National Science Foundation.
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