Engineers in California launched a series of seismic tests on a building to test its ability to function after earthquakes.
The structural engineers conducted the tests on the world’s largest outdoor "shake table" at the Englekirk Structural Engineering Center, which subjects the building to movements similar to real earthquakes.
The $5 million project aims to assess earthquake and fire readiness of elevators, fire systems, medical equipment and computer servers through the artificial earthquakes at the five-storey building.
It is the first time that the bearing system has been tested under a full-scale building on a shake table in the United States.
The project, which is supported by a coalition of government agencies, foundations and industry partners, aims to find out how to keep buildings such as hospitals and data centres operational after going through an earthquake.
Researchers also will assess whether the building’s fire barriers have been affected by the shakes.
“Today’s test was really a success in the sense that the base isolators below the building protected the nonstructural components from the damaging effects of the ground motions,” said Professor Tara Hutchinson of the Jacobs School of Engineering at UC San Diego, the project’s lead principal investigator.
“Had this building been occupied, it would remain operational after these earthquakes.”
During the first day of testing, the building was subjected to motions recorded during the 1994, 6.7-magnitude Northridge earthquake and 2010, 8.8-magnitude Chile earthquake.
The base of the building, which was equipped with cylindrical rubber bearings that isolate the five-story building from most of the lateral motion it would normally experience during a temblor, swayed significantly, but the 1.4 million pound structure resting on top of the isolators suffered little distortion.
“We did observe some minor damage on the interior, in particular things that are quite sensitive or brittle elements, such as partition walls, in the form of cracking of mud and tape, as well as movement of contents,” Professor Hutchinson said.
“But these are cosmetic, easily and economically repairable.”
Throughout the two weeks of testing, engineers will monitor the building’s performance with more than 500 high-fidelity sensors and more than 70 cameras that will record the movement of key elements and components inside the building.
“What we are doing is the equivalent of giving a building an EKG to see how it performs after an earthquake and a post-earthquake fire,” said Professor Hutchinson.
Read more about the project