A simulated earthquake at the University at Buffalo caused more severe damage to the test house than was originally noticed, researchers announced Thursday.
The seismic test conducted in November at UB's earthquake center is part of an international effort to improve construction codes and it drew national attention.
Researchers involved in the project said the extensive damage is not a concern and the test is yielding rich data that will be applied to future design work and testing.
"It's good news in a sense," said John van de Lindt, an associate professor of civil engineering at Colorado State University and a lead project researcher. "Anything that happened to that building enables us to learn more."
Engineers at UB and several other universities are working together on a four-year, federally funded attempt to design structures that can better withstand powerful earthquakes.
The $1.24 million project -- funded through the National Science Foundation -- included a first-of-its-kind test held Nov. 14 at UB's Structural Engineering and Earthquake Simulation Laboratory.
That test simulated the effect of 1994's Northridge, Calif., earthquake -- a magnitude 6.7 quake -- on an 80,000-pound, two-story wooden house.
The test house was built on top of two movable shake tables in the UB earthquake laboratory -- designed to simulate the destructive forces of a quake.
University officials said the simulation was the largest seismic test ever conducted on a wooden structure, and the UB facility was the only lab in the United States able to carry out the test.
The house initially appeared to survive the 15-second shake, covered by local and national media, with little damage beyond a television, lamp and computer monitor that fell to the floor.
However, further investigation, including analyzing data taken from a dozen video cameras and 250 sensors installed in the 1,800-square-foot house, found severe structural damage.
For example, the sill plates -- the wood attached to the house's concrete foundation -- were split and cracked around the building's perimeter, said Andre Filiatrault, a UB professor of civil engineering and lead UB researcher on the project.
As engineers continue to tally the true extent of the damage, it is becoming clear that an earthquake of this size would leave a home built to the current standards uninhabitable, Filiatrault said.
And any repairs to the sill plates and to other structural damage in the house could be cost-prohibitive, researchers said.
"I think the building performed pretty much according to the current standards, which [are] based on preventing loss of life," Filiatrault said. "However, our current standards do not address economic issues related to cost of repairs. And that's what our project is trying to address."