and treating the pipes, “before anything could be built on
top of them when work resumed in the summer of 2015.”
The new airport opened to passengers in December of 2017.
“The other challenge, besides logistics, is the quality of
the installation – and we took it very, very seriously,” Gesret
said. “If you have one nick, the CO2 will leak into the permafrost
and create a pocket inside somewhere, which is going to be
less or more frozen than the other part – in this case, the
building isn’t floating horizontally anymore, it’s going to tilt.
So you plan, you sequence, you supervise the work properly
– you control, you check.”
“You plan, you sequence, you control, you check”
“Everything used below grade is pressure-vessel quality
seamless piping,” said Panagapko, and rigorously tested for
leaks using mass spectrometer helium leak detection equipment
and nitrogen pressure testing once the pipes are laid.
“Anything above grade subjected to the environment is
completely cleaned and sand-blasted, then coated with a
flame-sprayed aluminized coating – similar to galvanizing,
but much more corrosion-resistant – and then a two-part
epoxy topcoat paint is applied on top of that,” he said.
Although it’s important that contractors don’t dig below
grade without insuring they’re aware of the system and
where the piping is, he adds, modern systems are very robust,
“with redundancy designed in,” so that failures on a loop, for
example, will be compensated by the loop that’s next to it.
About 70 people from Bouygues were working at the
site, including engineers and technicians who did the
specialized work, along with workers from the local Inuit
community, says Gesret. An international company with its
headquarters in Paris, France, and almost 130,000 employees,
Bouygues has done projects in 80 countries, but nothing
like this before, he adds.
“We may not build another thermosyphon system – what
matters is that we have that experience. Our first lesson was
that it’s possible to build everywhere as long as you understand
the local difficulties and you’re capable to work with them,” he
said. “It’s mainly a question of taking the time to understand
how it works and putting everything together.”
PROJECT SPOTLIGHT
“As soon as we activate the system
it maintains a frozen state for the
life of the system, with no need for
any maintenance or electrical input
from the building.”
– Justin Panagapko,
Arctic Foundations of Canada
52 Q3 2019 www.pilingcanada.ca
/www.pilingcanada.ca
