Structural Design and Construction Challenges on the South and West of Edmonton Area Development Project

In 2013, AltaLink initiated work on the South and West of Edmonton Area development project comprised of multiple 138-kV and 240-kV circuit modifications. Scopes included greenfield construction, rebuilding existing lines, and tapping existing lines to new substations. The complicated project scopes were challenging to construct due to outage constraints, environmental restrictions, and the need for multiple foundation solutions. Proper outage planning with the AltaLink Control Center was imperative and directly impacted the construction sequencing of the project. Environmental concerns affected the project in multiple ways: work restrictions during bird nesting and migration seasons, requirements for rig matting in environmentally sensitive and wet areas, and the use of vehicle wash stations. A variety of structure types were implemented on the project including double-circuit latticed steel towers, single-, double-, and triple-circuit tubular steel poles, and wood poles. Foundation types, including drilled shafts, helical foundations, and direct embed foundations, were selected based on structure type and location. Construction commenced in early 2017, and the project was placed in service in December 2017.