UCSD Jacobs School of Engineering University of California San Diego
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Jacobs School to Build World's First Outdoor Shake Table for Full-Scale Structural Earthquake Safety Tests

 

 

Structural engineers will be able to test buildings up to 60 ft. tall and structures weighing up to 2,200 tons.
The Jacobs School’s Structural Engineering Departmentis building the world’s first outdoor shake table. With its powerful hydraulic actuators capable of shakingat speeds up to 6 ft. per second, the equipmentwill create realistic simulations of the most devastating earthquakes ever recorded. At 25 ft by 40 ft., it will be the largest shake table in the United States.

The project is funded through a $5.9 million grantfrom the National Science Foundation with matching funds totaling $5 million from the state, industry partners and UCSD.

“This new outdoor laboratory will seal UCSD’s position as the innovation leader in structural testing for earthquake hazard mitigation,” said Frieder Seible, Interim Dean of the Jacobs School and director of the Charles Lee Powell Structural Research Laboratories. “Because there is no roof over the shake table, we will be able to use tall cranes and heavy equipment to construct and test full-scale buildings and structures, something that has not been possible before. We can now physically validate many construction systems that have previously only been analyzed through computer models.”

For example, the shake table will be used to validate the seismic safety of storage casks for spent nuclear fuel rods. Analytical models have shown that the containers would not crack under earthquake loads.

However, because the containers are so heavy and so big, there has previously been no shake table in the U.S. capable of testing the actual performance of casks in an earthquake. Next generation tests will also be done for multi-story buildings, bridge columns and bents, wharfs and piers, and lifeline structures such as electrical sub-stations.

The shake table is part of the National Science Foundation’s (NSF) effort to transform the nation’s ability to carry out earthquake engineering research. Through its George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), www.nees.org, NSF is providing $82 million to construct or enhance laboratories at more than 15 U.S. universities. All of the sites will be connected via the NEESgrid, an Internet-based network to make testing facilities and results available to researchers worldwide.

The large high performance outdoor shake table will be located at a new structural engineering field station to be constructed at Camp Elliott, located eight miles east of the campus. Adjacent to the shake table, UCSD is building a Soil Foundation-Structure Interaction (SFSI) Facility funded by the California Department of Transportation (Caltrans).
Taken together, the shake table and SFSI will allow for one of a kind testing of structural systems such as bridge abutments, embankments and foundations.

The field station at Camp Elliott is an extension of the Charles Lee Powell Structural Research Laboratories. The Powell Labs are world-renown for their capability for testing large-scale structural systems. Existing facilities include the Seismic Response Modification Device Testing Facility with a 16 ft. by 12 ft., sixdegree-of-freedom shake table designed to test new technologies to retrofit the state’s longest span bridges; the Structural Systems Laboratory for testing of buildings up to five stories tall and bridges up to 120 ft. long, and the Structural Components Laboratory which includes a 65 ft. long reaction wall for side-by-side testing of full- or large-scale components and a 16 ft. by 10 ft. uni-axial shake table.

Co-investigators on the NSF grant include Jacobs School Structural Engineering Professors Frieder Seible, Scott Ashford, Joel P. Conte, Ahmed-Waeil Elgamal, André Filiatrault, J. Enrique Luco, José Restrepo, and Chia-Ming Uang. Dr. Lelli Van Den Einde is the Project Manager and Larry Berman is the Sr. Development Engineer.

The shake table is expected to be fully operational by October 2004.