New B.C. highrises at risk in event of major quake: study
CTV.ca News Staff
Published Wednesday, January 26, 2011 8:19PM EST
Many recently constructed highrise buildings in British Columbia could topple or crumble in a major earthquake, according to a new study made public on Wednesday.
The University of British Columbia Earthquake Lab study found buildings made with six-inch concrete support walls aren't as resistant to earthquakes as previously believed, despite being fully compliant with building codes.
The news comes on the 311th anniversary of one of the strongest earthquakes ever recorded on North America's Pacific Coast, in 1700. About 460,000 B.C. residents marked the anniversary by participating in the country's largest simultaneous earthquake preparedness drill ever executed.
In his study, UBC's Prof. Perry Adebar looked at the devastating 8.8-magnitude Chilean earthquake in 2010, comparing it to what could happen if a quake hit B.C. He found many of Chile's older buildings stayed intact, while newer buildings were more likely to crumble.
The use of thinner walls has become popular in Chile and North America – where building codes are very similar – in order to fit more spots in underground parking garages and create more interior space.
"Chile is a very modern country and we have six-inch walls just like this in Canada," Adebar said, calling for changes to B.C.'s building codes. For existing buildings, he recommends reinforcing thin walls with carbon fibre – a costly and lengthy procedure.
Using simulated earthquakes in his lab, Adebar found buildings between 10 and 20 storeys were at the highest risk, as were those built on flood plains and on sandy soils – much like the terrain in Richmond, south of Vancouver.
Discovery Channel's Mark Miller, whose report on infrastructure failure during Chile's massive earthquake aired on "Daily Planet," said B.C.'s building codes aren't up for review until 2014.
In the meantime, it remains "perfectly legal to build with what may be flawed building techniques," he told CTV News Channel today.
Residents prepare for earthquake
Meanwhile on Wednesday, participants in churches, schools and offices across the province took cover at 10 a.m. local time for the Great British Columbia Shake Out. Provincial legislators, however, opted out of the drill, cancelling their planned participation moments before it began.
It was B.C.'s first time trying out such a test run, in which radio stations sounded a synchronized alarm urging participants to take cover. They were instructed to get under a table, hold on tight and stay there for one minute -- about two to five minutes short of the expected duration of a real quake.
Organizers also advised participants on what not to do: run.
"If you're downtown, do not run outside the building," echoed Miller. "(In Chile), some of the buildings lost their glass… You're going to survive the quake but you're going to die from a big chunk of glass hitting you in the head."
While B.C. hasn't had a major earthquake since 1700 -- a "megaquake" that shook the ground for at least five minutes -- it sits in a geological region that puts it at risk. Seismologists warn another major quake they're calling "The Big One" could happen anytime.
Miller, who visited Chile last March, says drills like the one today remind ordinary citizens of that possibility.
"It gets people thinking about where (they would) hide out, where (they would) put their kids," he said.
With its proximity to the ocean, B.C. could also be prone to a post-earthquake tsunami, so those near the water should plan an exit to higher ground.
"You might have 45 minutes, you might have less," he said.