million cubic metres of excavation and backfill, approxi-mately
300,000 cubic metres of concrete demolition, 21,000
metric tons of structural steel, 45 structures, (includ-ing
a cable-stayed bridge) and 440,000 square metres of
concrete paving.”
The enormity of the undertaking is further complicated by
the need to keep the roads and rail lines running, even while
one of the highways is being relocated. But before any of the
demolition and construction could begin, one of the first
challenges was soil remediation.
“Turcot Yard used to be an old railway yard,” Marcoux
said. “Every type of contamination needs to be managed
differently.” Because the project is so large, most of the con-taminated
material is being reused as backfill on the job
site. Of the approximately one million cubic metres of con-taminated
soil, about 90 per cent was reused, which greatly
reduced the truck miles expended on the job.
“All our backhoes are equipped with GPS, so the operator
of the equipment knows exactly where he is at all times. A 3D
model of the ground was done, so it really helps us manage
where we are,” said Marcoux.
He notes that a “huge spreadsheet” helps ensure that each
section of the site that will be receiving fill is ready on time.
It was based on information gleaned from 2,800 surveys that
went into creating a soil management plan based on reha-bilitation
principles which was designed to limit the project’s
ecological footprint.
Besides the contaminants, the geotechnical parameters of
the soils presented their own challenges. “There used to be
an old river, so there was also compressible material – clay
and peat. In some instances, they went down to bedrock,” he
said. This necessitated the drilling of close to 3,000 bore holes
down to competent material.
However, of all the site’s unique qualities, the most chal-lenging
was certainly the need to maintain traffic flow
throughout the project. Like a surgeon who must maintain
blood circulation during a tricky operation, the KPH Turcot
members (Kiewit, Parsons, CRH Canada Group Inc. and
WSP) knew they had to keep the traffic moving seamlessly
over the five-year reconstruction while roads, rails, ramps
and bridges were being removed and rebuilt.
“It’s an extremely challenging project. When you look at
it, it’s probably one of the most complex transportation jobs
right now in North America because of the proximity of other
structures,” said Marcoux. “We’re working in a very dense
urban area.”
For everyone on site, movement is restricted because of
the need to work with large pieces of machinery close to
live transportation routes, pedestrian corridors and existing
structures. In some cases, work has to be carried out under-neath
low structures. Vibration has to be carefully monitored
with a seismograph or survey prism. Just one element of traf-fic
management is the requirement to build 95,000 square
metres of permanent and temporary retaining walls.
PROJECT SPOTLIGHT
Just one element of traffic management is the
requirement to build 95,000 square metres of
permanent and temporary retaining walls.
54 Q2 2018 www.pilingcanada.ca
