The Drainage Tunnelling team completed 7 major projects for the city, University of Alberta and the City of Calgary.
- Mill Woods Double Barrel:
As part of a complicated network of tunnels and connections this project will help to remove stormwater from the existing double barrel pipe and reduce risk of flooding in southeast of Edmonton.
- West Edmonton Sanitary Sewer (WESS) Stage W-12:
The City’s Lovat tunnel boring machine has been used to cross under the North Saskatchewan River, involving 3 shafts, small diversion tunnels and a 1,200m siphon. The construction challenges were abandoned coal mines, the presence of methane gas, and difficult access and limited surface disruption on the Riverside Golf Course.
- University of Alberta:
A shaft of 3m deep and 6m in diameter, and a 34m long tunnel have been excavated.
- North Edmonton Sanitary Trunk (NEST) Tunnel:
The 3.7km long, 2.4m diameter tunnel is the longest tunnel completed from one working shaft. The tunnel connects to the existing pump station and access manholes with the expected completion in 2012.
- Rio Terrace/Quesnell Heights Tunnel:
An arch-shaped hand tunnel with 5 shafts was selected for this labour intensive project. Dinosaur bones were uncovered during the excavation, which drew the international media attention. When the tunnel is completed, it will connect to a new pump station to provide the necessary storage capacity to accommodate excess flows generated by severe rainfall and lessen the risk of sewer backup into basements.
- Calgary – Memorial Drive Project:
A tunnel was installed under Memorial Drive and passed under a rail system. A 24/7 schedule was operated for part of the project to minimize the settlement risk. The tunnel boring machine broke into the removal shaft on the north side of Memorial Drive before Christmas, setting the stage for the pipe installation.
- Calgary – 16th Avenue Project:
The tunnel project was a continuation of the Memorial Drive project. With the extremely hard ground conditions, the tunnel boring machine experienced enough stress that led the mole cutting teeth needed immediate replacement to avoid any delay in schedule.