In its initial public demonstration, the world's first seismic testing apparatus for nonstructural components performed exactly as designed last Friday at the University at Buffalo and MCEER, providing engineers with the first realistic, experimental method of simulating and evaluating how earthquakes damage building equipment, contents and components.
"These experiments clearly demonstrate new capabilities available at UB to test many types of nonstructural systems, whether they are attached to walls or connected between the top and bottom of a story in a building," Gilberto Mosqueda, Ph.D., assistant professor of civil, structural and environmental engineering in the UB School of Engineering and Applied Sciences said. "We look forward to assisting our industry partners in testing and improving the performance of their products during earthquakes."
Mitigation and response to extreme events, whether natural events like earthquakes and hurricanes, or manmade like terrorist attacks, is a research strategic strength identified in the UB 2020 strategic plan.
These recent tests were representative of a "design basis" earthquake, which has a 10 percent probability of occurring within the next 50 years and a "maximum considered earthquake," the largest earthquake shaking that a building could experience in its service life in a high-seismic zone in the U.S.
UB engineers and SEESL technicians constructed and equipped a 10-foot by 12-foot composite hospital room, outfitted with numerous systems typical of a critical-care facility, ranging from mechanical systems, such as sprinklers and medical gas lines, to ceiling-mounted surgical lamps, a suspended ceiling, infusion pumps and wall-mounted computer monitors.
"Ben," a crash dummy provided by Calspan, Inc., of Buffalo, was seated on top of a gurney that had been secured in its stationary position. Nonetheless, the gurney was tossed about like a toy in both tests, while "Ben" -- 180 pounds of dead weight -- hit the floor in the maximum event and was very severely tossed about in the design basis quake.
During the design basis earthquake test, UB engineers were surprised to see wall-mounted EKG monitors fall from their pedestals, since they were mounted according to current California standards. The maximum considered earthquake test caused a few ceiling tiles to fall.
"These failures highlight some potential vulnerabilities that should be further studied," said Andre Filiatrault, Ph.D., professor of civil, structural and environmental engineering at UB and director of SEESL.
The NCS is the only system in the world capable of realistically simulating how the contents and distributed systems (i.e., water, sprinkler, medical gas piping) in important buildings, such as hospitals, react to strong ground shaking and amplified floor motions, said Mosqueda.
While he cautioned that general conclusions cannot be drawn from these tests, which were conducted primarily to demonstrate the capabilities of the NCS, nonetheless, he said that these unexpected failures point to areas where engineers and manufacturers may want to focus their joint efforts in the future.
The National Science Foundation-funded Nonstructural Components Simulator (NCS) realistically simulated a fully equipped, upper-story hospital room experiencing two levels of seismic activity.
The demonstration took place in the Structural Engineering and Earthquake Simulation Laboratory (SEESL) in UB's School of Engineering and Applied Sciences for an audience of more than 100 earthquake engineers and industry representatives from across the U.S. who were attending the UB/MCEER symposium on "Seismic Regulations and Challenges for Protecting Building Equipment, Components and Operations."
Gilberto Mosqueda was lead designer and builder of the facility with Rodrigo Retamales, a doctoral student in the same department.
The NCS is coming online just as a consortium of universities, led by the University of Nevada at Reno, and including UB, has been awarded a five-year, $3.6 million National Science Foundation NEES Grand Challenge grant to investigate the performance of nonstructural systems during earthquakes.
For its portion of the research, UB's Department of Civil, Structural and Environmental Engineering will receive approximately $700,000.
In addition to complementary facilities at UNR, UB's Nonstructural Components Simulator and versatile, twin movable shake tables will provide a test bed for these research studies to conduct experiments to better understand and improve the seismic performance of nonstructural systems, particularly ceilings, piping and partition walls.
In addition to Filiatrault, Andre Reinhorn, Ph.D., Clifford C. Furnas Professor of Structural Engineering at UB and former SEESL director, and Andrew Whittaker, Ph.D., professor of civil, structural and environmental engineering will be leading the UB studies.
The testing platforms of the NCS were designed and constructed by UB engineers and SEESL staff; the hydraulic actuators that drive the system were manufactured by MTS Systems Corporation.
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