The scientists from the University of California-San Diego and the University of Arizona conducted the seismic tests on a half-scale, three-story, 1-million-pound concrete structure -- the largest footprint of any structure ever tested on a shake table in the United States.

A series of earthquake jolts as powerful as magnitude 8.0 on the Richter scale were used to test the seismic response of precast concrete floor systems used in structures such as parking garages, college dormitories, hotels, stadiums, prisons and office buildings.

The $2.3 million research project involved testing computer simulations to help design the three-story structure and to determine where sensors should be placed. The data recorded by the sensors were used to take measurements of certain physical phenomena on the structure such as displacements, strains and accelerations caused by the shaking; and to estimate forces in the structure.

The scientists said the $9 million University of California-San Diego shake table used in the research is the largest in the United States and the only outdoor shake table in the world.