Expert 'horrified' by Chch developers

Christchurch, backed by the University of Canterbury, leads the world in earthquake engineering design, according to Stephen Hogg. Photo / File / Supplied

Cutting-edge earthquake engineering technology emanating out of post-disaster Christchurch is being ignored by some owners in their haste to erect new buildings in the city, an industry expert fears.

Stephen Hogg, technical director for engineering firm Aurecon, has just returned from the 15th World Conference on Earthquake Engineering in Portugal.

He said that after listening to world experts discussing earthquake engineering design, it reinforces the fact that Christchurch, backed by the University of Canterbury, leads the world.

But he was "horrified" developers were not taking advantage of the world-leading technology and were in danger of "repeating the sins of the past".

"What has horrified me recently is that while walking around the city I am seeing buildings going up that are ignoring the earthquake engineering technology available on our doorstep," he said.

"Not only do we have the world's best technology here, backed by experts such as Professor Stefano Pampanin from the University of Canterbury, but the extra cost of making a building truly dynamic is so small, probably less than 1 per cent of the total build cost.

"Christchurch has the chance to build the best seismically resilient buildings in the world, but already we are starting to miss a few tricks."

Central to the low damage design solutions is the incorporation of anti-seismic devices inside the building, Hogg said.

"It's like having a building full of shock absorbers that have the ability to dampen seismic energy while also allowing the building to move with the quake's force, to be dynamic. Watch a car with good shock absorbers move and sway when on a bumpy road, it's the same principle.

"And the other good thing is that these building shock absorbers only cost a few hundred dollars per unit and can be replaced."

He said the old mantra that "earthquakes don't read design code" is still relevant, saying it is foolhardy to stick rigidly to code.

"The last earthquake was twice code and there is no reason that the next 'big one' might exceed the new code," Hogg said.

"What we need are buildings that are truly resilient, and the place to find that information is right here in Christchurch."