99th Avenue Sanitary Tunnel Bypass
- Duration: 2020-2024
- Client: EPCOR
- Project Type: Water/Wastewater
Project Overview
This project included the design and construction, and trenchless installation, of a new 1,800 mm nominal diameter ‘bypass’ sanitary tunnel, 1625 m in length. The alignment of this project included a crossing of the Mackinnon Racine and the construction of permanent drop structures and manholes, by passes and reconnections. The tunnel was to be approximately 30 m below street elevation and crossing at approximately 20 m below the ravine.
The design installation depth placed the tunnel close to the Empress Formation (Saskatchewan sand and gravel), within sandy clay, clay till soil conditions, with a high-water table and potential of encountering boulders and cobbles. Tunnelling within the sand players and high-water table required extreme care and attention to maintain the line and grade; and more importantly, control of ground loss which was the key to minimizing ground settlement.
![99th-1](https://scgcanada.ca/wp-content/uploads/2022/09/99th-1-scaled.jpg)
![99th-3](https://scgcanada.ca/wp-content/uploads/2022/09/99th-3.jpg)