Feb. 5, 2002
A Whole Lot of Shaking Going On
GW's Virginia Campus Unveils New Earthquake Lab Complete
With Hi-Tech "Shake Table"
By Greg Licamele
The shiny gray slab measures 10-feet-by-10-feet. It
weighs 4,000 pounds. Beneath it rests a huge mass of concrete weighing
approximately 170 tons. The platform can shake, rattle, and roll, as
well as twist, turn, and twirl.
The Earthquake Simulator at GW’s Virginia Campus
is a new research tool to study one primary area: the damage earthquakes
can inflict on structures, soil, and building materials. The School
of Engineering and Applied Science’s Center for Infrastructure
Safety and Reliability (CISR) will lead the research into past and potential
earthquakes.
“We’re looking at ways of minimizing hazards
to structure foundations due to earthquakes,” says Shahram Sarkani,
professor of engineering management and systems engineering and CISR
director. “We’re trying to design better foundations and design
better structures so that they can resist damage due to earthquakes.”
Created with a grant from the National Science Foundation
(NSF) the “Shake Table” is the only one of its kind on the
East Coast of the United States with six degrees of freedom, simulating
motion in three translational and three rotational degrees powered by
hydraulics. The accompanying computer program allows Sarkani and his
researchers to create earthquakes such as the 1994 Northridge, CA, earthquake
or the 1906 San Francisco disaster. By looking at these different quakes,
researchers can better understand how structures need to be built and
fortified to limit damage and loss of life.
Since Northern Virginia does not sit on a major fault
line, it might not be evident why GW would invest in such a project.
However, being at the “center of it all” means conducting
research to educate key government policy makers, Sarkani says.
“We’re trying to bring earthquakes to the
forefront of their thinking,” he says. “Hopefully, we’ll
make a positive impact in terms of future funding and future research.
Generally, unless you’re from a district that experienced an earthquake,
you probably don’t have a good idea of what’s going on.”
One NSF-funded project at the lab has researchers
looking at “smart” structures subjected to severe earthquake
ground motion. These so-called “smart” structures consist
of sensors, dampers, or controllers that can detect and modify the response
of the structure to a range of ground motions. In addition to this project,
other government agencies are taking notice of this shiny gray slab,
including the Department of Defense, the Department of Transportation,
the Federal Emergency Management Agency, and the American Red Cross.
“We expect to have models of footing and the
soil beneath it, as well as models of multi-story buildings,” says
Sarkani, noting the table can hold up to 35,000 pounds. “The sky’s
the limit. Whatever we can get funding for and get other people excited
about.”
In addition to providing essential information to
the federal government and researchers, the lab will facilitate the
learning of GW students by showing them what the destruction of an earthquake
can be versus looking at it in a book.
“There are courses that teach students about
what the dynamics and vibrations are and the effects of those on different
pieces of equipment or a building,” says Majid Manzari, associate
professor of civil engineering. “We will show them what vibrations
in equipment could cause, what kind of failure, etc., so this is for
students to see the relationship between theory and real life.”
Send feedback to: bygeorge@gwu.edu
