UCLA scientists simulated the effects of a major earthquake Thursday morning as part of ShakeOut, a disaster scenario drill that was enacted across Southern California.
The faculty from the Network for Earthquake Engineering Simulation at UCLA crushed concrete structural columns with seismic force to demonstrate the dangers that sub-standard reinforcement poses to buildings and human life.
In attendance were engineers, public policy makers and others from the International Earthquake Conference, taking place in Los Angeles through Friday for ShakeOut.
With 5.3 million participants, the ShakeOut drill turned out to be the largest in the country’s history, officials said.
Earthquake safety and preparedness are major issues in this region, and a better understanding of what could happen in the inevitable case of another big quake has pushed researchers to developing technologies that can potentially save lives.
UCLA engineers tested the strength of two typical building columns side by side during the earthquake simulation conducted at the NEES structures laboratory at UCLA.
The goal was to test the strength of two concrete structural columns side by side.
One of the columns, with an older, less earthquake-ready construction was painted a Trojan red. The other column, colored in Bruin blue, was reinforced with a stronger web of internal steel rebar.
Using massive machinery, the engineers then placed the weight of a 2-3 story building upon both columns, while shaking them back and forth with the strength of up to a magnitude 9.0 earthquake.
The effect was an earthquake in slow-motion, said John Wallace, a UCLA professor of civil and environmental engineering and the event’s lead presenter.
As the simulated quake progressed, thick cracks emerged in the older of the two columns. Meanwhile, the newer column bent easily without breaking.
After about ten minutes of shaking, the weaker column had lost much of its concrete and was on the verge of collapse.
The stronger column sustained a few cracks but still stood tall.
The newer column’s stronger web of internal rebar helped it withstand the simulation, said Robert Nigbor, a principal investigator for the NEES.
“Concrete by itself is sort of like chalk. You put a force on it and it breaks,” Nigbor said.
“If you put steel in it, it becomes less brittle.”
Under real-world circumstances, the older column with less steel would have collapsed completely, Nigbor said.
The demonstration was important because Los Angeles building codes do not currently require the use of the newer pillars, also known as ductile columns, he added.
Greig Smith, a L.A. city council member who recently introduced legislation to require more ductile columns in local buildings, was pleased by Thursday’s demonstration.
“I think it proved the point I’ve been making,” Smith said.
Steve Powell, a Waste Management employee visiting with the International Earthquake Conference, said the destruction of the non-ductile column accentuated the importance of earthquake preparedness.
“It was pretty graphic. It really drives the point home,” Powell said.
Outside the NEES lab, the rest of UCLA and the larger southland area participated in the ShakeOut drill Thursday morning.
UCLA used BruinAlert, a text and email notification system, around 10 a.m. to remind students, faculty and staff to practice for a real earthquake.
The scenario presented by ShakeOut was a magnitude 7.8 quake along the San Andreas fault.
The Los Angeles area is long overdue for a major earthquake. The area hasn’t experienced one in well over 100 years.
“It will come, but people forget,” Nigbor said.
ShakeOut coordinators hoped the drill would dramatically increase local awareness about the threat of earthquakes.
“This is really all about education,” said Debbie Weiser, a ShakeOut steering committee member.
Although that committee will officially evaluate ShakeOut’s effectiveness later in the month, those involved said Thursday already seemed like a big success.
“Over a million people registered,” Nigbor said.
“That’s huge.”