Joint venture begins work on West Diamond
Published: February 26th 2009
Source: Daily Commercial News
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and complex rail grade separation in Toronto is employing the expertise
of two foundation contractors to get the job done.
West Diamond Joint Venture, a partnership of Bermingham Foundation
Solutions and Anchor Shoring & Caissons Ltd., recently started
installing steel pipe pile and caisson walls for the $277-million
Toronto West Diamond grade separation.
Designed by Delcan, the separation will allow east-west double CN rail
lines to pass underneath double north-south CP lines instead of crossing
them, as has been the case since the 1880s when the junction area of
west Toronto was settled. The term diamond stems from the shape where
the four lines converge.
The new underpass will eliminate scheduling conflicts between CP freight
trains, which have the right of way over passenger trains, including GO
Transit’s heavily used Georgetown-to-Toronto commuter service.
“The West Toronto Diamond rail-to-rail grade separation is one of the
largest and most comprehensive projects in the GO Transit Rail
Improvement Program,” says Gary McNeil, managing director of GO Transit.
Not only will the separation allow GO Trains and freight trains to pass
through the area with fewer interruptions, but it will also lay the
groundwork for future development of GO Train service for customers for
that part of the Greater Toronto Area, says McNeil.
But the much anticipated interrupted train service from Georgetown to
downtown Toronto won’t occur until sometime in 2011 when the project is
It will take at least 18 months just to install foundation walls along
the approximately one-kilometre route, says Bermingham Foundation’s
chief executive officer Patrick Bermingham. The actual excavation will
be handled by a different contractor later in the project schedule.
The magnitude of the
undertaking is the reason his firm formed the joint venture with Anchor.
“If we took on this project alone, we wouldn’t have the resources to
take on any other ones.”
The walls will be comprised of 36-inch diameter steel piles which will
be driven into the ground along the route by two 165-ton cranes and a
160-ton crane with hammers that have 200,000-pound energy rating and
they will be set to a depth ranging from 30 to 70 feet, he says.
“We’re building both a foundation wall and cofferdam as the train tracks
will be passing, not just below grade, but also below the water table.”
To ensure very tight tolerances, five piles are installed in a sequenced
operation. “We install the first, third and fifth piles and then come
back and hammer in the second and fourth ones. This is done to ensure
each pile goes in vertically and doesn’t lean.”
The piles are linked with “PT” connections which enable the joints to be
grouted, forming a tight water barrier. “It’s a system commonly used in
Japan, but not so much here,” says Bermingham.
“This is a very technical and challenging project,” adds Anchor project
manager Toben Jerry.
Not only are the crews working adjacent to active rail lines with
numerous trains passing daily, the site is located in very densely
populated area close to homes and businesses.
Construction practices used by the joint venture partners are designed
to impose minimum risks to the environment, the buildings, services and
utilities, while ensuring worker safety, says Jerry.
“When a train passes through, all work has to stop until we get the all
clear signal from CN officials.”
This first phase of the project requires installation of three permanent
walls and temporary shoring walls which will ensure safe train
diversions and protect sensitive foundation structures. The first phase
will be completed in 2010.
Later phases will include drilling out the 36-inch diameter interlocking
pipe piles and placing concrete within them to form a composite steel
and concrete section.
The interlocking pipe pile walls will provide lateral support by
retaining earth as the grade of the train rails are relocated under the
CP rails and Weston Road to the west. At those locations, the walls will
also provide vertical structural support for future bridge
installations, says Jerry.