COVER FEATURE
One of the first of its kind in Alberta, the Fort McMurray
West 500-kV Transmission Project (WFMAC) is
owned by Alberta PowerLine, a partnership between
ATCO and Quanta Services, Inc. This is the first proj-ect
awarded under the newly instituted Competitive Process
by the Alberta Electric System Operator.
Working under this partnership, Valard Construction,
a Quanta subsidiary, oversaw the full engineering, pro-curement
and construction of 500 kilometres of 500-kV
transmission line from the Genesee area west of Edmonton
to Fort McMurray in Northern Alberta. Included in this
construction were the foundations for two substations that
occurred concurrently with the line.
This project required the installation of over 6,500 driven
pipe piles, 250 large diameter drilled shaft foundations
(requiring over 9,000 cubic metres of concrete) and almost
5,000 helical piles with more than 6,500 extensions being
added. All of this work was done in weather that ranged
from 35°C during the summer to -45°C in the winter, and
in mud, sleet, rain, fog and blizzard conditions. Completed
in just 13 months (between September 2017 and October
2018) the bulk of the foundation program was finished over
four months early, marking a monumental achievement for
Northstar Sharp’s Foundation Specialists.
Unique design considerations
Over the course of 2016, under the direction of Valard and
working alongside other Quanta subsidiaries, the project
team designed and refined a family of towers and foundations
that could accommodate both the stresses of the northern
Alberta climate as well as the varied subsurface conditions
expected on the project. The focus was on constructability
and efficiency in execution.
Then an extensive front-end geotechnical program
was initiated under environmental supervision ahead of
construction contract execution to help identify critical geo-technical
areas. Testing and sampling was completed ahead
of the design process to augment the design and procure-ment
phases. This geotechnical process continued alongside
the right-of-way (ROW) development and provided geotech-nical
incite on every proposed foundation site for the project.
Using the data obtained, a comprehensive foundation
design package was produced with input from both the
transmission line design team and the construction leader-ship
responsible for installations in the field. By involving the
field-based teams in the overall design, the Northstar Sharp’s
team was well versed with the requirements and project
needs prior to construction start.
A team of geotechnical engineers was maintained
throughout the project to review incoming site data, assess
design applications, assign installation criteria as well as sign
off on actual executed installation. The close relationship
between design engineering and pile installation allowed for
PHOTOS COURTESY OF NORTHSTAR SHARP’S FOUNDATION SPECIALISTS
CONTINUED ON PAGE 27
PILING CANADA 25