Tribune/Nathan Orme - UNRR engineering students make final preparations for Thursday's earthquake simulation. In the foreground, a display shows pieces of the model bridge that was tested in the seismic experiment.
Tribune/Nathan Orme - Ashkan Vosooghi, a student working on his doctorate in structural and earthquake engineering at UNR, measures cracks in the model bridge that was subjected to an 8.0 simulated earthquake on Thursday.
The principal investigator of the research project was civil and environmental engineering professor Mehdi Saiidi, who said, "This is a unique experiment because we are using several innovative materials like nickel/titanium alloys and polyvinyl fibers mixed with cement."
The quarter-scale bridge, measuring 110 feet long, 10 feet high, 8 feet wide and topped with large concrete blocks, was shaken with bidirectional forces to realistically simulate an earthquake to determine if the use of new materials would make bridges less likely to collapse.
The National Science Foundation helped fund the earthquake simulation, Saiidi said, and the equipment site is connected to the NSF’s George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES) consortium of 15 universities, which compiles data and conducts experiments to develop new ways of constructing "seismic-resistant" structures.
"Having these universities all participate in earthquake research follows the ideal model of research," Vice President for Research and Dean of the College of Engineering Marsha Read said. "That is, the more collaborative research you have, the better it will be."
Two of the nearby universities in the NEES Consortium are the University of California, Berkeley and University of California, San Diego. Even in the company of such prestigious schools, UNR is unique in its contribution to the consortium's effort.
"This (UNR) is the only university in the country that has three shake tables, which are responsible for the actual earthquake simulations," Read said. "We have visitors come from other countries to see the research conducted in the large structures laboratory. It serves as an important tool for recruiting new engineering students to the college."
Thursday’s test took place in the university's Center for Civil Engineering Earthquake Research headquarters.
"The center has a $10 million state-of-the-art laboratory in the field of bridge engineering," Saiidi said. "The laboratory has powerful shake tables with the capability of simulating large earthquakes."
Saiidi described the purpose of a large-scale structures lab, saying, "A large-scale structures lab can create an earthquake on demand. This enables us to study the ability of a structure to withstand earthquake effects without having to wait for the next real earthquake."
After the tests took place, engineering students examined the structure to see how the parts of the bridge made of the various materials fared.
"We used new types of materials," graduate student Arash Esmaili said. "The outcome, just by looking at how the traditional materials and the new ones were affected, was that the new materials were able to withstand much more pressure than the traditional concrete mixtures."
After the series of tests, the bridge was left standing, with the majority of damage done to the areas of the bridge that were not made of the new materials. The tests were important since they revealed the effectiveness of using components like nickel and titanium to build bridges.
"The tests show that these new materials could be an integral part of the next generation of seismic resistant bridge construction," Esmaili said.
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