Whole Lotta Shakin ’ Going On
PRECISION VISION Data from sensors , digital cameras and aerial drones allowed for an incredibly detailed digital model of the building .
Did you know UC San Diego is home to the world ’ s largest outdoor shake table ? Here ’ s some more facts to be aware of :
IF THE PROSPECT of a mega-earthquake has you quaking yourself — fear not , because UC San Diego engineers are making sure our world will withstand the rumble . Researchers at the Jacobs School of Engineering are preparing to mitigate the effects of a largescale earthquake by testing a six-story , lightweight steel-frame building to determine how it will fare during a tremor and fires that may follow .
The structure , the tallest cold-formed steel-frame structure to undergo tests on a shake table , was built to represent a multifamily residential condominium or apartment . It was placed through a series of simulated temblors of increasing intensity that mimicked actual earthquakes .
As a better way to determine stress on the materials , the building ’ s performance was captured by an extensive array of more than 250 analog sensors , as well as digital cameras and aerial drones . Structural engineering professor Falko Kuester , who leads UC San Diego ’ s DroneLab , used unmanned aerial vehicles ( UAVs ) to capture both the seismic and fire testing and create a high-resolution 3-D model and video of observed damage . Engineers can use virtual reality ( VR ) to zoom in to see the tiniest details , such as cracks and changes in shape and color .
“ This is big VR for big data and big science ,” says Kuester .
As for the building ? “ It could have been easily repaired ,” said structural engineering professor Tara Hutchinson . “ The occupants would have gotten out safely .” Hutchinson believes the structure fared well because it is lighter than a concrete building and has less mass to generate damaging forces .
Fire was less kind to the structure , however . Plastic fixtures and hardware melted , as did several video cameras installed to capture the fire ’ s progression . Simulated quakes occurring after the fire tests further weakened the structure ’ s floors , bringing it close to collapse .
All the better to learn these effects in a test environment , however . The combination of these technologies — a one-of-a-kind outdoor shake table and powerful data visualization methods — allows structural engineers at the Jacobs School to produce an incredibly detailed digital model of the structures they test . This in turn allows them to make recommendations to improve design methods and building codes around the nation and around the world for when the Big One , or maybe the Mega One , hits .
12 years strong
The table has been shaking things up since 2004 and supports up to 2,000 tons — about 400 elephants ( or 11 of the Stuart Collection ' s Bear sculptures .)
Seismic mimicry
It can replicate the ground motion of the world ’ s largest earthquakes , including California ’ s 6.7-magnitude Northridge earthquake ( 1994 ), the 7.2-magnitude Cape Mendocino earthquake ( 1972 ) and the 8.8-magnitude Maule , Chile earthquake ( 2010 ).
Local motion
The table is located just off the I-15 highway and Pomerado Road ( though you ’ d never notice without a bright green building on top .)
Video star
Structural failures are recorded for analysis — watch the walls come tumbling down at tritonmag . com / shaketable
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