If the orebody is the heart of a mining operation, the
haul roads are its arteries. Keep them in good shape,
and equipment will move efficiently. Allow them to
deteriorate, and the well-being of the entire operation
can be at risk.
The haul road programs of most open pit operations in
Canada share three common considerations: safety, environmental
management and equipment management.
Good roads are safer and can contribute to lower vehicle
emissions, better water management and longer equipment
Adapting the terrain
Each year, four to five kilometres of new haul roads are
built at Syncrude Canada’s Mildred Lake and Aurora
mines. These roads are designed to last the duration of the
mine life and their construction is a multi-staged process
involving collaboration between different company teams.
At the outset, the long-range planners design the layout
of the road, accounting for expected volumes of traffic and
the timing and scheduling of production activities. Once
the design is in place, it is up to the short-range planning
group to incorporate its requirements into the overall operation
plans and to secure the timely supply of the requisite
materials. Finally, the job of having the roads built goes to
the haul road construction group, which oversees the contractors.
As one might expect, the actual road construction
process entails some very intricate steps.
Crowned subgrades need to be constructed first, providing
a solid foundation for the road. The crown prevents
the water that seeps through the granular layer immediately
above it from permeating the subgrade and helps
drain it off the road. Operations at
Syncrude don’t stop for the weather, so
the roads are built to handle it.
“The subgrades are the most important
part,” says Rod Walsh, a field
supervisor who has been with
Syncrude for 23 years. “You can have
the best granulars, but the road will
break down if it doesn’t have a solid
Due to differences in the materials
available at the two mines, their road
designs vary. At Mildred Lake,
Cretaceous-era marine clays, packed to 101 per cent of
proctor, are used as a subgrade material. At Aurora,
these marine clays are not available, so lean oil sand is
used to build the subgrade, which is not as effective. To
balance it out, alterations are made to the rest of the
Once Syncrude builds and approves the subgrade, local
contractors construct the roads. Approximately $8 to $10
million — $2 million a kilometre — is spent on road construction
annually at both mines.
Pit-run gravel and sands found on Syncrude’s own lease
are used to construct the base. However, Ken Bell, technical
leader, Mildred Lake, foresees a shortage of this
material in the future. “So we need to be innovative in our
approach to smart granular management,” he says.
Granular usage can be reduced by “flipping” or
reclaiming materials from roads no longer in use. This
road recycling offers several advantages. Less granular
needs to come out of the quarry, water management
becomes easier, material haul distances are
shortened and royalties need not be paid for the recycled
materials. Once the road is built and tested, it is
signed off to the operations people, who assume
responsibility for its maintenance.