Mass homelessness top concern for B.C. seismic engineers

B.C. builds to some of the highest seismic standards in the world. So you might assume the majority of us would be able to return to our homes after a major earthquake. 

Turns out, it's not quite that simple. 

Engineers design buildings today for what they term "life safety" during the main event, which means your building will likely still be standing when the ground stops shaking.

That's the good news, says Perry Adebar, head of UBC's civil engineering department. 

"But the code doesn't ensure that a building can be usable. So people will leave the building safely and perhaps never re-enter." 

Tens of thousands with nowhere to live

Adebar points to Christchurch, New Zealand, as an example. After that city's 2011 earthquake, teams of engineers inspected 3,000 buildings in the downtown core — and yellow or red-tagged 45 percent of them because of safety issues. 

By February 2015, 1,240 of those buildings had been demolished.

You might say that the best thing that could happen to our area is a small earthquake ... and everyone will start to realize yes, this is real- Perry Adebar

This is the scenario that worries B.C.'s engineering and emergency planning communities most. Metro Vancouver has seven times the population of Christchurch and 20 times the density. If the earthquake strikes close enough to the Lower Mainland, Adebar predicts as many as 100,000 people could be displaced. 

And there is no easy way to know which buildings will be OK.

Older buildings may be fine — but maybe not

So if you're eyeing your 1960s-era, four-storey walk-up with suspicion, Adebar says age isn't necessarily the deciding factor. Design, materials, upgrades, soil conditions — these all come into play. 

"There's generally a belief that the older the building, the worse it will do. But I don't agree with that. I've looked at drawings of older buildings that will do very well," he said.

"On the other hand, we have brand new buildings which won't collapse, but I am pretty certain will be badly damaged." 

Victoria is facing an equally grim scenario, but for a different reason — its large stock of buildings from the late 1800s and early 1900s, including single-family homes, are all built on unstable soil. 

B.C. lacking engineering expertise 

Adding to the problem, says Adebar, is the fact that B.C. doesn't have the expertise necessary to determine what's safe and what isn't. 

"Most engineers aren't really going to have the experience and the knowledge to make an accurate assessment. So, they're going to err on the side of caution. It increases the chance that you will not be able to get back into your building, because somebody has said this one may be unsafe." 

It's a looming disaster that, Adebar says, the engineering community is finally beginning to wake to, as colleagues increasingly look for better ways to collaborate, to train and to understand what resilient design looks like. 

But Adebar worries it may not be happening fast enough. 

"You might say that the best thing that could happen to our area is a small earthquake that damages a few buildings, doesn't hurt anybody, and everyone will start to realize yes, this is real. This could really happen."

Only then, he says, will we — individuals, scientists, government — be forced to take resiliency seriously.