Researchers from the University at Buffalo conducted the state's first large-scale earthquake simulation on Tuesday to determine how prone unreinforced masonry walls are to quake damage.
The test took place at UB’s Multidisciplinary Center for Earthquake Engineering Research (MCEER) where two 14-foot-tall walls, made to replicate turn-of-the-20th-century row houses stood parallel to one another during several tests.
The left wall was built with 100 year old brick and mortar similar to “brownstones” found in New York City. The right wall was built stronger and retrofitted using techniques typical on the West Coast, where there's more seismic activity.
The first few quakes were designed to imitate the 2011, 5.8 magnitude Virginia earthquake. During the Virginia test you could see very little movement between the walls. Then researchers conducted a mockup of the 2011 Christchurch, New Zealand earthquake. They completed three Christchurch tests, starting at 50 percent, then 75 percent and finally moving on to 100 percent of the destructive 6.1 magnitude quake.
Researchers say while New York City is not a zone with high seismic activity, the potential damage from an earthquake is significant due to the city's aging infrastructure and large population.
UB research assistant Maikol Del Carpio says the retrofitted wall held up much better in the set of experiments.
"This [simulated damage] could have probably killed a person. If someone was walking on the street, the parapet would have fallen down. On the other side where the wall was retrofitted using braces we validated there was no damage to the parapet. So the retrofitted technique was validated, at least for this experiment," Del Carpio said.
UB doctoral student Juan Aleman spearheaded the experiment for his thesis project. He says that data being collected can be put to good use by structural engineers.
"The engineering community doesn't have numerical, computer tools to analyze these types of buildings," said Aleman. "They want to analyze the buildings and see if these buildings will be able to sustain an earthquake, but they don't know how to do it."
Aleman says the test results will also be used to calculate the potential property or human loss that quakes like this can cause.
MCEER along with the Structural Engineers Association of New York (SEAoNY) and the International Masonry Institute (IMI) conducted the experiment.