Home Projects

Lower Churchill Project

See all Projects

Project Description

The Lower Churchill Project is intended to develop the hydroelectric potential of the Churchill River.  Phase I, referred to as Muskrat Falls, includes more than 800 miles of high voltage transmission line through the remote, rugged terrain of Newfoundland and Labrador, Canada.

Team Members

Nalcor Energy, Valard, Crux Subsurface

Crux’s Role

Original foundation designs for the alignment included grillage and driven piles, but variable bedrock depths and boggy ground conditions created installation challenges.  Crux was engaged to provide a design-build micropile alternative at select structure locations, the number of which continued to expand throughout the project.

Designs were developed for both self-supporting and guyed structures, and factored in bog up to 25 feet as well as variable bedrock quality.  The construction approach provided a flexible solution that could be adapted onsite if geotechnical conditions differed from expectations.  In total, Crux designed and installed micropile foundations for 161 structures to depths of up to 70 feet.

Site access in the remote, rugged terrain presented challenges to the project, and access roads were constructed across the alignment.  During the winter months, the frozen ground provided sufficient support for equipment traveling off the access roads.  During the remaining seasons, rig mats were used onsite to support equipment.

Additional challenges included working in temperatures close to -40°C/-40°F.  To mitigate this, all equipment included an on-board heating system and insulation; a heated pressure washer was used to clean the drill at the end of each shift; all-thread bar and hardware required heating to above 5°C/41°F prior to installation; and an insulated blanket was wrapped around the grouted piles to protect fresh grout from freezing.

 

 

Related Projects

Lolo-Oxbow 230 kV Transmission Line Rebuild

Micropile design and construction for four remote-access river crossing structures requiring an alternative foundation option.

View Project
Antimony to Burke A&B Transmission Rebuild

Project Description The Antimony to Burke project involved the rebuild of an approximately 13-mile 115 kV transmission line between Western Montana and Eastern Idaho.  The...

View Project
Paris to Ark City Transmission Line

Project Description The Paris to Ark City Transmission Line involved upgrading an existing power system originally built in the 1940’s and nearing the end of...

View Project
Copyright © 2021 Crux Subsurface, Inc.
Back to Top