Courtesy of UC San Diego

The NHERI Large High Performance Outdoor Shake Table (LHPOST6) at the University of California, San Diego is the world's largest outdoor earthquake simulator.

A recent $16.8 million grant from the National Science Foundation along with an additional $3.4 million of in-kind support from UC San Diego expanded the shake table’s testing capabilities to more realistically recreate the ground motions during strong earthquakes. The facility can test some of the heaviest specimens in the world, from multi-story buildings to bridge columns, bridge bents, and wind turbines, now with the ability to reproduce a full range of earthquake ground motions.

Until the 2022 upgrade, the shake table could only move back and forth in one direction. The upgrade to 6 degrees of freedom (DOF) allows the table to move in six directions - back and forth, up and down, left to right, as well as rotate in all three directions. Reproducing earthquake motions in 6-DOF is key because during a temblor, the ground may move in any direction. Because it is outdoors, the LHPOST6 allows for testing of much taller structures than any other shake table.

The shake table is also capable of testing large industrial systems, such as heating and air conditioning units for hospitals, and large electrical transformers for utility companies and the power grid. And, as more big cities such as Los Angeles, San Francisco and Seattle are looking to retrofit old buildings for seismic safety, large to full-scale tests of retrofit systems, some of which can only be done on a shake table like ours, will be required.

The newly upgraded LHPOST6 will address research needs pertinent to design and construction practices in the United States and worldwide and will drive improvements in design codes and standards as well as transformative seismic-resilient concepts.  

Operational since 2004, the LHPOST6 is the first known large-scale structural testing laboratory in the United States to demonstrate compliance with the International Standards Organization ISO/IEC 17025 [International Organization for Standardization ISO, 2018]. The operation and maintenance of the shake table are currently funded through a grant from NSF's Natural Hazards Engineering Research Infrastructure (NHERI) Program, administered by the UC San Diego Department of Structural Engineering.